fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81
  82 /*
  83  * Lock ordering
  84  *
  85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  87  *
  88  * page fault path:
  89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  90  *   page lock -> i_data_sem (rw)
  91  *
  92  * buffered write path:
  93  * sb_start_write -> i_mutex -> mmap_sem
  94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  95  *   i_data_sem (rw)
  96  *
  97  * truncate:
  98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
  99  *   i_mmap_rwsem (w) -> page lock
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   transaction start -> i_data_sem (rw)
 102  *
 103  * direct IO:
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 106  *   transaction start -> i_data_sem (rw)
 107  *
 108  * writepages:
 109  * transaction start -> page lock(s) -> i_data_sem (rw)
 110  */
 111
 112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 113 static struct file_system_type ext2_fs_type = {
 114         .owner          = THIS_MODULE,
 115         .name           = "ext2",
 116         .mount          = ext4_mount,
 117         .kill_sb        = kill_block_super,
 118         .fs_flags       = FS_REQUIRES_DEV,
 119 };
 120 MODULE_ALIAS_FS("ext2");
 121 MODULE_ALIAS("ext2");
 122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 123 #else
 124 #define IS_EXT2_SB(sb) (0)
 125 #endif
 126
 127
 128 static struct file_system_type ext3_fs_type = {
 129         .owner          = THIS_MODULE,
 130         .name           = "ext3",
 131         .mount          = ext4_mount,
 132         .kill_sb        = kill_block_super,
 133         .fs_flags       = FS_REQUIRES_DEV,
 134 };
 135 MODULE_ALIAS_FS("ext3");
 136 MODULE_ALIAS("ext3");
 137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 138
 139 static int ext4_verify_csum_type(struct super_block *sb,
 140                                  struct ext4_super_block *es)
 141 {
 142         if (!ext4_has_feature_metadata_csum(sb))
 143                 return 1;
 144
 145         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 146 }
 147
 148 static __le32 ext4_superblock_csum(struct super_block *sb,
 149                                    struct ext4_super_block *es)
 150 {
 151         struct ext4_sb_info *sbi = EXT4_SB(sb);
 152         int offset = offsetof(struct ext4_super_block, s_checksum);
 153         __u32 csum;
 154
 155         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 156
 157         return cpu_to_le32(csum);
 158 }
 159
 160 static int ext4_superblock_csum_verify(struct super_block *sb,
 161                                        struct ext4_super_block *es)
 162 {
 163         if (!ext4_has_metadata_csum(sb))
 164                 return 1;
 165
 166         return es->s_checksum == ext4_superblock_csum(sb, es);
 167 }
 168
 169 void ext4_superblock_csum_set(struct super_block *sb)
 170 {
 171         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 172
 173         if (!ext4_has_metadata_csum(sb))
 174                 return;
 175
 176         es->s_checksum = ext4_superblock_csum(sb, es);
 177 }
 178
 179 void *ext4_kvmalloc(size_t size, gfp_t flags)
 180 {
 181         void *ret;
 182
 183         ret = kmalloc(size, flags | __GFP_NOWARN);
 184         if (!ret)
 185                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 186         return ret;
 187 }
 188
 189 void *ext4_kvzalloc(size_t size, gfp_t flags)
 190 {
 191         void *ret;
 192
 193         ret = kzalloc(size, flags | __GFP_NOWARN);
 194         if (!ret)
 195                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 196         return ret;
 197 }
 198
 199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 200                                struct ext4_group_desc *bg)
 201 {
 202         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 203                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 204                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 205 }
 206
 207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 208                                struct ext4_group_desc *bg)
 209 {
 210         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 211                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 212                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 213 }
 214
 215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 216                               struct ext4_group_desc *bg)
 217 {
 218         return le32_to_cpu(bg->bg_inode_table_lo) |
 219                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 220                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 221 }
 222
 223 __u32 ext4_free_group_clusters(struct super_block *sb,
 224                                struct ext4_group_desc *bg)
 225 {
 226         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 227                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 228                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 229 }
 230
 231 __u32 ext4_free_inodes_count(struct super_block *sb,
 232                               struct ext4_group_desc *bg)
 233 {
 234         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 235                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 236                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 237 }
 238
 239 __u32 ext4_used_dirs_count(struct super_block *sb,
 240                               struct ext4_group_desc *bg)
 241 {
 242         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 243                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 244                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 245 }
 246
 247 __u32 ext4_itable_unused_count(struct super_block *sb,
 248                               struct ext4_group_desc *bg)
 249 {
 250         return le16_to_cpu(bg->bg_itable_unused_lo) |
 251                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 252                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 253 }
 254
 255 void ext4_block_bitmap_set(struct super_block *sb,
 256                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 257 {
 258         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 259         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 260                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 261 }
 262
 263 void ext4_inode_bitmap_set(struct super_block *sb,
 264                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 265 {
 266         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 267         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 268                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 269 }
 270
 271 void ext4_inode_table_set(struct super_block *sb,
 272                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 273 {
 274         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 275         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 276                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 277 }
 278
 279 void ext4_free_group_clusters_set(struct super_block *sb,
 280                                   struct ext4_group_desc *bg, __u32 count)
 281 {
 282         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 283         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 284                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 285 }
 286
 287 void ext4_free_inodes_set(struct super_block *sb,
 288                           struct ext4_group_desc *bg, __u32 count)
 289 {
 290         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 291         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 292                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 293 }
 294
 295 void ext4_used_dirs_set(struct super_block *sb,
 296                           struct ext4_group_desc *bg, __u32 count)
 297 {
 298         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 299         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 300                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 301 }
 302
 303 void ext4_itable_unused_set(struct super_block *sb,
 304                           struct ext4_group_desc *bg, __u32 count)
 305 {
 306         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 307         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 308                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 309 }
 310
 311
 312 static void __save_error_info(struct super_block *sb, const char *func,
 313                             unsigned int line)
 314 {
 315         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 316
 317         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 318         if (bdev_read_only(sb->s_bdev))
 319                 return;
 320         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 321         es->s_last_error_time = cpu_to_le32(get_seconds());
 322         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 323         es->s_last_error_line = cpu_to_le32(line);
 324         if (!es->s_first_error_time) {
 325                 es->s_first_error_time = es->s_last_error_time;
 326                 strncpy(es->s_first_error_func, func,
 327                         sizeof(es->s_first_error_func));
 328                 es->s_first_error_line = cpu_to_le32(line);
 329                 es->s_first_error_ino = es->s_last_error_ino;
 330                 es->s_first_error_block = es->s_last_error_block;
 331         }
 332         /*
 333          * Start the daily error reporting function if it hasn't been
 334          * started already
 335          */
 336         if (!es->s_error_count)
 337                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 338         le32_add_cpu(&es->s_error_count, 1);
 339 }
 340
 341 static void save_error_info(struct super_block *sb, const char *func,
 342                             unsigned int line)
 343 {
 344         __save_error_info(sb, func, line);
 345         ext4_commit_super(sb, 1);
 346 }
 347
 348 /*
 349  * The del_gendisk() function uninitializes the disk-specific data
 350  * structures, including the bdi structure, without telling anyone
 351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 353  * This is a kludge to prevent these oops until we can put in a proper
 354  * hook in del_gendisk() to inform the VFS and file system layers.
 355  */
 356 static int block_device_ejected(struct super_block *sb)
 357 {
 358         struct inode *bd_inode = sb->s_bdev->bd_inode;
 359         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 360
 361         return bdi->dev == NULL;
 362 }
 363
 364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 365 {
 366         struct super_block              *sb = journal->j_private;
 367         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 368         int                             error = is_journal_aborted(journal);
 369         struct ext4_journal_cb_entry    *jce;
 370
 371         BUG_ON(txn->t_state == T_FINISHED);
 372         spin_lock(&sbi->s_md_lock);
 373         while (!list_empty(&txn->t_private_list)) {
 374                 jce = list_entry(txn->t_private_list.next,
 375                                  struct ext4_journal_cb_entry, jce_list);
 376                 list_del_init(&jce->jce_list);
 377                 spin_unlock(&sbi->s_md_lock);
 378                 jce->jce_func(sb, jce, error);
 379                 spin_lock(&sbi->s_md_lock);
 380         }
 381         spin_unlock(&sbi->s_md_lock);
 382 }
 383
 384 /* Deal with the reporting of failure conditions on a filesystem such as
 385  * inconsistencies detected or read IO failures.
 386  *
 387  * On ext2, we can store the error state of the filesystem in the
 388  * superblock.  That is not possible on ext4, because we may have other
 389  * write ordering constraints on the superblock which prevent us from
 390  * writing it out straight away; and given that the journal is about to
 391  * be aborted, we can't rely on the current, or future, transactions to
 392  * write out the superblock safely.
 393  *
 394  * We'll just use the jbd2_journal_abort() error code to record an error in
 395  * the journal instead.  On recovery, the journal will complain about
 396  * that error until we've noted it down and cleared it.
 397  */
 398
 399 static void ext4_handle_error(struct super_block *sb)
 400 {
 401         if (sb->s_flags & MS_RDONLY)
 402                 return;
 403
 404         if (!test_opt(sb, ERRORS_CONT)) {
 405                 journal_t *journal = EXT4_SB(sb)->s_journal;
 406
 407                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 408                 if (journal)
 409                         jbd2_journal_abort(journal, -EIO);
 410         }
 411         if (test_opt(sb, ERRORS_RO)) {
 412                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 413                 /*
 414                  * Make sure updated value of ->s_mount_flags will be visible
 415                  * before ->s_flags update
 416                  */
 417                 smp_wmb();
 418                 sb->s_flags |= MS_RDONLY;
 419         }
 420         if (test_opt(sb, ERRORS_PANIC)) {
 421                 if (EXT4_SB(sb)->s_journal &&
 422                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 423                         return;
 424                 panic("EXT4-fs (device %s): panic forced after error\n",
 425                         sb->s_id);
 426         }
 427 }
 428
 429 #define ext4_error_ratelimit(sb)                                        \
 430                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 431                              "EXT4-fs error")
 432
 433 void __ext4_error(struct super_block *sb, const char *function,
 434                   unsigned int line, const char *fmt, ...)
 435 {
 436         struct va_format vaf;
 437         va_list args;
 438
 439         if (ext4_error_ratelimit(sb)) {
 440                 va_start(args, fmt);
 441                 vaf.fmt = fmt;
 442                 vaf.va = &args;
 443                 printk(KERN_CRIT
 444                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 445                        sb->s_id, function, line, current->comm, &vaf);
 446                 va_end(args);
 447         }
 448         save_error_info(sb, function, line);
 449         ext4_handle_error(sb);
 450 }
 451
 452 void __ext4_error_inode(struct inode *inode, const char *function,
 453                         unsigned int line, ext4_fsblk_t block,
 454                         const char *fmt, ...)
 455 {
 456         va_list args;
 457         struct va_format vaf;
 458         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 459
 460         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 461         es->s_last_error_block = cpu_to_le64(block);
 462         if (ext4_error_ratelimit(inode->i_sb)) {
 463                 va_start(args, fmt);
 464                 vaf.fmt = fmt;
 465                 vaf.va = &args;
 466                 if (block)
 467                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 468                                "inode #%lu: block %llu: comm %s: %pV\n",
 469                                inode->i_sb->s_id, function, line, inode->i_ino,
 470                                block, current->comm, &vaf);
 471                 else
 472                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 473                                "inode #%lu: comm %s: %pV\n",
 474                                inode->i_sb->s_id, function, line, inode->i_ino,
 475                                current->comm, &vaf);
 476                 va_end(args);
 477         }
 478         save_error_info(inode->i_sb, function, line);
 479         ext4_handle_error(inode->i_sb);
 480 }
 481
 482 void __ext4_error_file(struct file *file, const char *function,
 483                        unsigned int line, ext4_fsblk_t block,
 484                        const char *fmt, ...)
 485 {
 486         va_list args;
 487         struct va_format vaf;
 488         struct ext4_super_block *es;
 489         struct inode *inode = file_inode(file);
 490         char pathname[80], *path;
 491
 492         es = EXT4_SB(inode->i_sb)->s_es;
 493         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 494         if (ext4_error_ratelimit(inode->i_sb)) {
 495                 path = file_path(file, pathname, sizeof(pathname));
 496                 if (IS_ERR(path))
 497                         path = "(unknown)";
 498                 va_start(args, fmt);
 499                 vaf.fmt = fmt;
 500                 vaf.va = &args;
 501                 if (block)
 502                         printk(KERN_CRIT
 503                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 504                                "block %llu: comm %s: path %s: %pV\n",
 505                                inode->i_sb->s_id, function, line, inode->i_ino,
 506                                block, current->comm, path, &vaf);
 507                 else
 508                         printk(KERN_CRIT
 509                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 510                                "comm %s: path %s: %pV\n",
 511                                inode->i_sb->s_id, function, line, inode->i_ino,
 512                                current->comm, path, &vaf);
 513                 va_end(args);
 514         }
 515         save_error_info(inode->i_sb, function, line);
 516         ext4_handle_error(inode->i_sb);
 517 }
 518
 519 const char *ext4_decode_error(struct super_block *sb, int errno,
 520                               char nbuf[16])
 521 {
 522         char *errstr = NULL;
 523
 524         switch (errno) {
 525         case -EFSCORRUPTED:
 526                 errstr = "Corrupt filesystem";
 527                 break;
 528         case -EFSBADCRC:
 529                 errstr = "Filesystem failed CRC";
 530                 break;
 531         case -EIO:
 532                 errstr = "IO failure";
 533                 break;
 534         case -ENOMEM:
 535                 errstr = "Out of memory";
 536                 break;
 537         case -EROFS:
 538                 if (!sb || (EXT4_SB(sb)->s_journal &&
 539                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 540                         errstr = "Journal has aborted";
 541                 else
 542                         errstr = "Readonly filesystem";
 543                 break;
 544         default:
 545                 /* If the caller passed in an extra buffer for unknown
 546                  * errors, textualise them now.  Else we just return
 547                  * NULL. */
 548                 if (nbuf) {
 549                         /* Check for truncated error codes... */
 550                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 551                                 errstr = nbuf;
 552                 }
 553                 break;
 554         }
 555
 556         return errstr;
 557 }
 558
 559 /* __ext4_std_error decodes expected errors from journaling functions
 560  * automatically and invokes the appropriate error response.  */
 561
 562 void __ext4_std_error(struct super_block *sb, const char *function,
 563                       unsigned int line, int errno)
 564 {
 565         char nbuf[16];
 566         const char *errstr;
 567
 568         /* Special case: if the error is EROFS, and we're not already
 569          * inside a transaction, then there's really no point in logging
 570          * an error. */
 571         if (errno == -EROFS && journal_current_handle() == NULL &&
 572             (sb->s_flags & MS_RDONLY))
 573                 return;
 574
 575         if (ext4_error_ratelimit(sb)) {
 576                 errstr = ext4_decode_error(sb, errno, nbuf);
 577                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 578                        sb->s_id, function, line, errstr);
 579         }
 580
 581         save_error_info(sb, function, line);
 582         ext4_handle_error(sb);
 583 }
 584
 585 /*
 586  * ext4_abort is a much stronger failure handler than ext4_error.  The
 587  * abort function may be used to deal with unrecoverable failures such
 588  * as journal IO errors or ENOMEM at a critical moment in log management.
 589  *
 590  * We unconditionally force the filesystem into an ABORT|READONLY state,
 591  * unless the error response on the fs has been set to panic in which
 592  * case we take the easy way out and panic immediately.
 593  */
 594
 595 void __ext4_abort(struct super_block *sb, const char *function,
 596                 unsigned int line, const char *fmt, ...)
 597 {
 598         va_list args;
 599
 600         save_error_info(sb, function, line);
 601         va_start(args, fmt);
 602         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 603                function, line);
 604         vprintk(fmt, args);
 605         printk("\n");
 606         va_end(args);
 607
 608         if ((sb->s_flags & MS_RDONLY) == 0) {
 609                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 610                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 611                 /*
 612                  * Make sure updated value of ->s_mount_flags will be visible
 613                  * before ->s_flags update
 614                  */
 615                 smp_wmb();
 616                 sb->s_flags |= MS_RDONLY;
 617                 if (EXT4_SB(sb)->s_journal)
 618                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 619                 save_error_info(sb, function, line);
 620         }
 621         if (test_opt(sb, ERRORS_PANIC)) {
 622                 if (EXT4_SB(sb)->s_journal &&
 623                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 624                         return;
 625                 panic("EXT4-fs panic from previous error\n");
 626         }
 627 }
 628
 629 void __ext4_msg(struct super_block *sb,
 630                 const char *prefix, const char *fmt, ...)
 631 {
 632         struct va_format vaf;
 633         va_list args;
 634
 635         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 636                 return;
 637
 638         va_start(args, fmt);
 639         vaf.fmt = fmt;
 640         vaf.va = &args;
 641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 642         va_end(args);
 643 }
 644
 645 #define ext4_warning_ratelimit(sb)                                      \
 646                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 647                              "EXT4-fs warning")
 648
 649 void __ext4_warning(struct super_block *sb, const char *function,
 650                     unsigned int line, const char *fmt, ...)
 651 {
 652         struct va_format vaf;
 653         va_list args;
 654
 655         if (!ext4_warning_ratelimit(sb))
 656                 return;
 657
 658         va_start(args, fmt);
 659         vaf.fmt = fmt;
 660         vaf.va = &args;
 661         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 662                sb->s_id, function, line, &vaf);
 663         va_end(args);
 664 }
 665
 666 void __ext4_warning_inode(const struct inode *inode, const char *function,
 667                           unsigned int line, const char *fmt, ...)
 668 {
 669         struct va_format vaf;
 670         va_list args;
 671
 672         if (!ext4_warning_ratelimit(inode->i_sb))
 673                 return;
 674
 675         va_start(args, fmt);
 676         vaf.fmt = fmt;
 677         vaf.va = &args;
 678         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 679                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 680                function, line, inode->i_ino, current->comm, &vaf);
 681         va_end(args);
 682 }
 683
 684 void __ext4_grp_locked_error(const char *function, unsigned int line,
 685                              struct super_block *sb, ext4_group_t grp,
 686                              unsigned long ino, ext4_fsblk_t block,
 687                              const char *fmt, ...)
 688 __releases(bitlock)
 689 __acquires(bitlock)
 690 {
 691         struct va_format vaf;
 692         va_list args;
 693         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 694
 695         es->s_last_error_ino = cpu_to_le32(ino);
 696         es->s_last_error_block = cpu_to_le64(block);
 697         __save_error_info(sb, function, line);
 698
 699         if (ext4_error_ratelimit(sb)) {
 700                 va_start(args, fmt);
 701                 vaf.fmt = fmt;
 702                 vaf.va = &args;
 703                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 704                        sb->s_id, function, line, grp);
 705                 if (ino)
 706                         printk(KERN_CONT "inode %lu: ", ino);
 707                 if (block)
 708                         printk(KERN_CONT "block %llu:",
 709                                (unsigned long long) block);
 710                 printk(KERN_CONT "%pV\n", &vaf);
 711                 va_end(args);
 712         }
 713
 714         if (test_opt(sb, ERRORS_CONT)) {
 715                 ext4_commit_super(sb, 0);
 716                 return;
 717         }
 718
 719         ext4_unlock_group(sb, grp);
 720         ext4_handle_error(sb);
 721         /*
 722          * We only get here in the ERRORS_RO case; relocking the group
 723          * may be dangerous, but nothing bad will happen since the
 724          * filesystem will have already been marked read/only and the
 725          * journal has been aborted.  We return 1 as a hint to callers
 726          * who might what to use the return value from
 727          * ext4_grp_locked_error() to distinguish between the
 728          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 729          * aggressively from the ext4 function in question, with a
 730          * more appropriate error code.
 731          */
 732         ext4_lock_group(sb, grp);
 733         return;
 734 }
 735
 736 void ext4_update_dynamic_rev(struct super_block *sb)
 737 {
 738         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 739
 740         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 741                 return;
 742
 743         ext4_warning(sb,
 744                      "updating to rev %d because of new feature flag, "
 745                      "running e2fsck is recommended",
 746                      EXT4_DYNAMIC_REV);
 747
 748         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 749         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 750         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 751         /* leave es->s_feature_*compat flags alone */
 752         /* es->s_uuid will be set by e2fsck if empty */
 753
 754         /*
 755          * The rest of the superblock fields should be zero, and if not it
 756          * means they are likely already in use, so leave them alone.  We
 757          * can leave it up to e2fsck to clean up any inconsistencies there.
 758          */
 759 }
 760
 761 /*
 762  * Open the external journal device
 763  */
 764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 765 {
 766         struct block_device *bdev;
 767         char b[BDEVNAME_SIZE];
 768
 769         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 770         if (IS_ERR(bdev))
 771                 goto fail;
 772         return bdev;
 773
 774 fail:
 775         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 776                         __bdevname(dev, b), PTR_ERR(bdev));
 777         return NULL;
 778 }
 779
 780 /*
 781  * Release the journal device
 782  */
 783 static void ext4_blkdev_put(struct block_device *bdev)
 784 {
 785         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 786 }
 787
 788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 789 {
 790         struct block_device *bdev;
 791         bdev = sbi->journal_bdev;
 792         if (bdev) {
 793                 ext4_blkdev_put(bdev);
 794                 sbi->journal_bdev = NULL;
 795         }
 796 }
 797
 798 static inline struct inode *orphan_list_entry(struct list_head *l)
 799 {
 800         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 801 }
 802
 803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 804 {
 805         struct list_head *l;
 806
 807         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 808                  le32_to_cpu(sbi->s_es->s_last_orphan));
 809
 810         printk(KERN_ERR "sb_info orphan list:\n");
 811         list_for_each(l, &sbi->s_orphan) {
 812                 struct inode *inode = orphan_list_entry(l);
 813                 printk(KERN_ERR "  "
 814                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 815                        inode->i_sb->s_id, inode->i_ino, inode,
 816                        inode->i_mode, inode->i_nlink,
 817                        NEXT_ORPHAN(inode));
 818         }
 819 }
 820
 821 static void ext4_put_super(struct super_block *sb)
 822 {
 823         struct ext4_sb_info *sbi = EXT4_SB(sb);
 824         struct ext4_super_block *es = sbi->s_es;
 825         int i, err;
 826
 827         ext4_unregister_li_request(sb);
 828         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 829
 830         flush_workqueue(sbi->rsv_conversion_wq);
 831         destroy_workqueue(sbi->rsv_conversion_wq);
 832
 833         if (sbi->s_journal) {
 834                 err = jbd2_journal_destroy(sbi->s_journal);
 835                 sbi->s_journal = NULL;
 836                 if (err < 0)
 837                         ext4_abort(sb, "Couldn't clean up the journal");
 838         }
 839
 840         ext4_unregister_sysfs(sb);
 841         ext4_es_unregister_shrinker(sbi);
 842         del_timer_sync(&sbi->s_err_report);
 843         ext4_release_system_zone(sb);
 844         ext4_mb_release(sb);
 845         ext4_ext_release(sb);
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 ext4_clear_feature_journal_needs_recovery(sb);
 849                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 850         }
 851         if (!(sb->s_flags & MS_RDONLY))
 852                 ext4_commit_super(sb, 1);
 853
 854         for (i = 0; i < sbi->s_gdb_count; i++)
 855                 brelse(sbi->s_group_desc[i]);
 856         kvfree(sbi->s_group_desc);
 857         kvfree(sbi->s_flex_groups);
 858         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 859         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 860         percpu_counter_destroy(&sbi->s_dirs_counter);
 861         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 862         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 863         brelse(sbi->s_sbh);
 864 #ifdef CONFIG_QUOTA
 865         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 866                 kfree(sbi->s_qf_names[i]);
 867 #endif
 868
 869         /* Debugging code just in case the in-memory inode orphan list
 870          * isn't empty.  The on-disk one can be non-empty if we've
 871          * detected an error and taken the fs readonly, but the
 872          * in-memory list had better be clean by this point. */
 873         if (!list_empty(&sbi->s_orphan))
 874                 dump_orphan_list(sb, sbi);
 875         J_ASSERT(list_empty(&sbi->s_orphan));
 876
 877         sync_blockdev(sb->s_bdev);
 878         invalidate_bdev(sb->s_bdev);
 879         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 880                 /*
 881                  * Invalidate the journal device's buffers.  We don't want them
 882                  * floating about in memory - the physical journal device may
 883                  * hotswapped, and it breaks the `ro-after' testing code.
 884                  */
 885                 sync_blockdev(sbi->journal_bdev);
 886                 invalidate_bdev(sbi->journal_bdev);
 887                 ext4_blkdev_remove(sbi);
 888         }
 889         if (sbi->s_mb_cache) {
 890                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 891                 sbi->s_mb_cache = NULL;
 892         }
 893         if (sbi->s_mmp_tsk)
 894                 kthread_stop(sbi->s_mmp_tsk);
 895         sb->s_fs_info = NULL;
 896         /*
 897          * Now that we are completely done shutting down the
 898          * superblock, we need to actually destroy the kobject.
 899          */
 900         kobject_put(&sbi->s_kobj);
 901         wait_for_completion(&sbi->s_kobj_unregister);
 902         if (sbi->s_chksum_driver)
 903                 crypto_free_shash(sbi->s_chksum_driver);
 904         kfree(sbi->s_blockgroup_lock);
 905         kfree(sbi);
 906 }
 907
 908 static struct kmem_cache *ext4_inode_cachep;
 909
 910 /*
 911  * Called inside transaction, so use GFP_NOFS
 912  */
 913 static struct inode *ext4_alloc_inode(struct super_block *sb)
 914 {
 915         struct ext4_inode_info *ei;
 916
 917         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 918         if (!ei)
 919                 return NULL;
 920
 921         ei->vfs_inode.i_version = 1;
 922         spin_lock_init(&ei->i_raw_lock);
 923         INIT_LIST_HEAD(&ei->i_prealloc_list);
 924         spin_lock_init(&ei->i_prealloc_lock);
 925         ext4_es_init_tree(&ei->i_es_tree);
 926         rwlock_init(&ei->i_es_lock);
 927         INIT_LIST_HEAD(&ei->i_es_list);
 928         ei->i_es_all_nr = 0;
 929         ei->i_es_shk_nr = 0;
 930         ei->i_es_shrink_lblk = 0;
 931         ei->i_reserved_data_blocks = 0;
 932         ei->i_reserved_meta_blocks = 0;
 933         ei->i_allocated_meta_blocks = 0;
 934         ei->i_da_metadata_calc_len = 0;
 935         ei->i_da_metadata_calc_last_lblock = 0;
 936         spin_lock_init(&(ei->i_block_reservation_lock));
 937 #ifdef CONFIG_QUOTA
 938         ei->i_reserved_quota = 0;
 939         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 940 #endif
 941         ei->jinode = NULL;
 942         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 943         spin_lock_init(&ei->i_completed_io_lock);
 944         ei->i_sync_tid = 0;
 945         ei->i_datasync_tid = 0;
 946         atomic_set(&ei->i_unwritten, 0);
 947         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 948         return &ei->vfs_inode;
 949 }
 950
 951 static int ext4_drop_inode(struct inode *inode)
 952 {
 953         int drop = generic_drop_inode(inode);
 954
 955         trace_ext4_drop_inode(inode, drop);
 956         return drop;
 957 }
 958
 959 static void ext4_i_callback(struct rcu_head *head)
 960 {
 961         struct inode *inode = container_of(head, struct inode, i_rcu);
 962         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 963 }
 964
 965 static void ext4_destroy_inode(struct inode *inode)
 966 {
 967         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 968                 ext4_msg(inode->i_sb, KERN_ERR,
 969                          "Inode %lu (%p): orphan list check failed!",
 970                          inode->i_ino, EXT4_I(inode));
 971                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 972                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 973                                 true);
 974                 dump_stack();
 975         }
 976         call_rcu(&inode->i_rcu, ext4_i_callback);
 977 }
 978
 979 static void init_once(void *foo)
 980 {
 981         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 982
 983         INIT_LIST_HEAD(&ei->i_orphan);
 984         init_rwsem(&ei->xattr_sem);
 985         init_rwsem(&ei->i_data_sem);
 986         init_rwsem(&ei->i_mmap_sem);
 987         inode_init_once(&ei->vfs_inode);
 988 }
 989
 990 static int __init init_inodecache(void)
 991 {
 992         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 993                                              sizeof(struct ext4_inode_info),
 994                                              0, (SLAB_RECLAIM_ACCOUNT|
 995                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 996                                              init_once);
 997         if (ext4_inode_cachep == NULL)
 998                 return -ENOMEM;
 999         return 0;
1000 }
1001
1002 static void destroy_inodecache(void)
1003 {
1004         /*
1005          * Make sure all delayed rcu free inodes are flushed before we
1006          * destroy cache.
1007          */
1008         rcu_barrier();
1009         kmem_cache_destroy(ext4_inode_cachep);
1010 }
1011
1012 void ext4_clear_inode(struct inode *inode)
1013 {
1014         invalidate_inode_buffers(inode);
1015         clear_inode(inode);
1016         dquot_drop(inode);
1017         ext4_discard_preallocations(inode);
1018         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1019         if (EXT4_I(inode)->jinode) {
1020                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1021                                                EXT4_I(inode)->jinode);
1022                 jbd2_free_inode(EXT4_I(inode)->jinode);
1023                 EXT4_I(inode)->jinode = NULL;
1024         }
1025 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1026         fscrypt_put_encryption_info(inode, NULL);
1027 #endif
1028 }
1029
1030 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1031                                         u64 ino, u32 generation)
1032 {
1033         struct inode *inode;
1034
1035         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1036                 return ERR_PTR(-ESTALE);
1037         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1038                 return ERR_PTR(-ESTALE);
1039
1040         /* iget isn't really right if the inode is currently unallocated!!
1041          *
1042          * ext4_read_inode will return a bad_inode if the inode had been
1043          * deleted, so we should be safe.
1044          *
1045          * Currently we don't know the generation for parent directory, so
1046          * a generation of 0 means "accept any"
1047          */
1048         inode = ext4_iget_normal(sb, ino);
1049         if (IS_ERR(inode))
1050                 return ERR_CAST(inode);
1051         if (generation && inode->i_generation != generation) {
1052                 iput(inode);
1053                 return ERR_PTR(-ESTALE);
1054         }
1055
1056         return inode;
1057 }
1058
1059 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1060                                         int fh_len, int fh_type)
1061 {
1062         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1063                                     ext4_nfs_get_inode);
1064 }
1065
1066 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1067                                         int fh_len, int fh_type)
1068 {
1069         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1070                                     ext4_nfs_get_inode);
1071 }
1072
1073 /*
1074  * Try to release metadata pages (indirect blocks, directories) which are
1075  * mapped via the block device.  Since these pages could have journal heads
1076  * which would prevent try_to_free_buffers() from freeing them, we must use
1077  * jbd2 layer's try_to_free_buffers() function to release them.
1078  */
1079 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1080                                  gfp_t wait)
1081 {
1082         journal_t *journal = EXT4_SB(sb)->s_journal;
1083
1084         WARN_ON(PageChecked(page));
1085         if (!page_has_buffers(page))
1086                 return 0;
1087         if (journal)
1088                 return jbd2_journal_try_to_free_buffers(journal, page,
1089                                                 wait & ~__GFP_DIRECT_RECLAIM);
1090         return try_to_free_buffers(page);
1091 }
1092
1093 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1094 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1095 {
1096         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1097                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1098 }
1099
1100 static int ext4_key_prefix(struct inode *inode, u8 **key)
1101 {
1102         *key = EXT4_SB(inode->i_sb)->key_prefix;
1103         return EXT4_SB(inode->i_sb)->key_prefix_size;
1104 }
1105
1106 static int ext4_prepare_context(struct inode *inode)
1107 {
1108         return ext4_convert_inline_data(inode);
1109 }
1110
1111 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1112                                                         void *fs_data)
1113 {
1114         handle_t *handle;
1115         int res, res2;
1116
1117         /* fs_data is null when internally used. */
1118         if (fs_data) {
1119                 res  = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1120                                 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1121                                 len, 0);
1122                 if (!res) {
1123                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1124                         ext4_clear_inode_state(inode,
1125                                         EXT4_STATE_MAY_INLINE_DATA);
1126                 }
1127                 return res;
1128         }
1129
1130         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1131                         ext4_jbd2_credits_xattr(inode));
1132         if (IS_ERR(handle))
1133                 return PTR_ERR(handle);
1134
1135         res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1136                         EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
1137                         len, 0);
1138         if (!res) {
1139                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1140                 res = ext4_mark_inode_dirty(handle, inode);
1141                 if (res)
1142                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1143         }
1144         res2 = ext4_journal_stop(handle);
1145         if (!res)
1146                 res = res2;
1147         return res;
1148 }
1149
1150 static int ext4_dummy_context(struct inode *inode)
1151 {
1152         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1153 }
1154
1155 static unsigned ext4_max_namelen(struct inode *inode)
1156 {
1157         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1158                 EXT4_NAME_LEN;
1159 }
1160
1161 static struct fscrypt_operations ext4_cryptops = {
1162         .get_context            = ext4_get_context,
1163         .key_prefix             = ext4_key_prefix,
1164         .prepare_context        = ext4_prepare_context,
1165         .set_context            = ext4_set_context,
1166         .dummy_context          = ext4_dummy_context,
1167         .is_encrypted           = ext4_encrypted_inode,
1168         .empty_dir              = ext4_empty_dir,
1169         .max_namelen            = ext4_max_namelen,
1170 };
1171 #else
1172 static struct fscrypt_operations ext4_cryptops = {
1173         .is_encrypted           = ext4_encrypted_inode,
1174 };
1175 #endif
1176
1177 #ifdef CONFIG_QUOTA
1178 static char *quotatypes[] = INITQFNAMES;
1179 #define QTYPE2NAME(t) (quotatypes[t])
1180
1181 static int ext4_write_dquot(struct dquot *dquot);
1182 static int ext4_acquire_dquot(struct dquot *dquot);
1183 static int ext4_release_dquot(struct dquot *dquot);
1184 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1185 static int ext4_write_info(struct super_block *sb, int type);
1186 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1187                          struct path *path);
1188 static int ext4_quota_off(struct super_block *sb, int type);
1189 static int ext4_quota_on_mount(struct super_block *sb, int type);
1190 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1191                                size_t len, loff_t off);
1192 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1193                                 const char *data, size_t len, loff_t off);
1194 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1195                              unsigned int flags);
1196 static int ext4_enable_quotas(struct super_block *sb);
1197 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1198
1199 static struct dquot **ext4_get_dquots(struct inode *inode)
1200 {
1201         return EXT4_I(inode)->i_dquot;
1202 }
1203
1204 static const struct dquot_operations ext4_quota_operations = {
1205         .get_reserved_space = ext4_get_reserved_space,
1206         .write_dquot    = ext4_write_dquot,
1207         .acquire_dquot  = ext4_acquire_dquot,
1208         .release_dquot  = ext4_release_dquot,
1209         .mark_dirty     = ext4_mark_dquot_dirty,
1210         .write_info     = ext4_write_info,
1211         .alloc_dquot    = dquot_alloc,
1212         .destroy_dquot  = dquot_destroy,
1213         .get_projid     = ext4_get_projid,
1214         .get_next_id    = ext4_get_next_id,
1215 };
1216
1217 static const struct quotactl_ops ext4_qctl_operations = {
1218         .quota_on       = ext4_quota_on,
1219         .quota_off      = ext4_quota_off,
1220         .quota_sync     = dquot_quota_sync,
1221         .get_state      = dquot_get_state,
1222         .set_info       = dquot_set_dqinfo,
1223         .get_dqblk      = dquot_get_dqblk,
1224         .set_dqblk      = dquot_set_dqblk,
1225         .get_nextdqblk  = dquot_get_next_dqblk,
1226 };
1227 #endif
1228
1229 static const struct super_operations ext4_sops = {
1230         .alloc_inode    = ext4_alloc_inode,
1231         .destroy_inode  = ext4_destroy_inode,
1232         .write_inode    = ext4_write_inode,
1233         .dirty_inode    = ext4_dirty_inode,
1234         .drop_inode     = ext4_drop_inode,
1235         .evict_inode    = ext4_evict_inode,
1236         .put_super      = ext4_put_super,
1237         .sync_fs        = ext4_sync_fs,
1238         .freeze_fs      = ext4_freeze,
1239         .unfreeze_fs    = ext4_unfreeze,
1240         .statfs         = ext4_statfs,
1241         .remount_fs     = ext4_remount,
1242         .show_options   = ext4_show_options,
1243 #ifdef CONFIG_QUOTA
1244         .quota_read     = ext4_quota_read,
1245         .quota_write    = ext4_quota_write,
1246         .get_dquots     = ext4_get_dquots,
1247 #endif
1248         .bdev_try_to_free_page = bdev_try_to_free_page,
1249 };
1250
1251 static const struct export_operations ext4_export_ops = {
1252         .fh_to_dentry = ext4_fh_to_dentry,
1253         .fh_to_parent = ext4_fh_to_parent,
1254         .get_parent = ext4_get_parent,
1255 };
1256
1257 enum {
1258         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1259         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1260         Opt_nouid32, Opt_debug, Opt_removed,
1261         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1262         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1263         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1264         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1265         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1266         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1267         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1268         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1269         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1270         Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1271         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1272         Opt_lazytime, Opt_nolazytime,
1273         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1274         Opt_inode_readahead_blks, Opt_journal_ioprio,
1275         Opt_dioread_nolock, Opt_dioread_lock,
1276         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1277         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1278 };
1279
1280 static const match_table_t tokens = {
1281         {Opt_bsd_df, "bsddf"},
1282         {Opt_minix_df, "minixdf"},
1283         {Opt_grpid, "grpid"},
1284         {Opt_grpid, "bsdgroups"},
1285         {Opt_nogrpid, "nogrpid"},
1286         {Opt_nogrpid, "sysvgroups"},
1287         {Opt_resgid, "resgid=%u"},
1288         {Opt_resuid, "resuid=%u"},
1289         {Opt_sb, "sb=%u"},
1290         {Opt_err_cont, "errors=continue"},
1291         {Opt_err_panic, "errors=panic"},
1292         {Opt_err_ro, "errors=remount-ro"},
1293         {Opt_nouid32, "nouid32"},
1294         {Opt_debug, "debug"},
1295         {Opt_removed, "oldalloc"},
1296         {Opt_removed, "orlov"},
1297         {Opt_user_xattr, "user_xattr"},
1298         {Opt_nouser_xattr, "nouser_xattr"},
1299         {Opt_acl, "acl"},
1300         {Opt_noacl, "noacl"},
1301         {Opt_noload, "norecovery"},
1302         {Opt_noload, "noload"},
1303         {Opt_removed, "nobh"},
1304         {Opt_removed, "bh"},
1305         {Opt_commit, "commit=%u"},
1306         {Opt_min_batch_time, "min_batch_time=%u"},
1307         {Opt_max_batch_time, "max_batch_time=%u"},
1308         {Opt_journal_dev, "journal_dev=%u"},
1309         {Opt_journal_path, "journal_path=%s"},
1310         {Opt_journal_checksum, "journal_checksum"},
1311         {Opt_nojournal_checksum, "nojournal_checksum"},
1312         {Opt_journal_async_commit, "journal_async_commit"},
1313         {Opt_abort, "abort"},
1314         {Opt_data_journal, "data=journal"},
1315         {Opt_data_ordered, "data=ordered"},
1316         {Opt_data_writeback, "data=writeback"},
1317         {Opt_data_err_abort, "data_err=abort"},
1318         {Opt_data_err_ignore, "data_err=ignore"},
1319         {Opt_offusrjquota, "usrjquota="},
1320         {Opt_usrjquota, "usrjquota=%s"},
1321         {Opt_offgrpjquota, "grpjquota="},
1322         {Opt_grpjquota, "grpjquota=%s"},
1323         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1324         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1325         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1326         {Opt_grpquota, "grpquota"},
1327         {Opt_noquota, "noquota"},
1328         {Opt_quota, "quota"},
1329         {Opt_usrquota, "usrquota"},
1330         {Opt_barrier, "barrier=%u"},
1331         {Opt_barrier, "barrier"},
1332         {Opt_nobarrier, "nobarrier"},
1333         {Opt_i_version, "i_version"},
1334         {Opt_dax, "dax"},
1335         {Opt_stripe, "stripe=%u"},
1336         {Opt_delalloc, "delalloc"},
1337         {Opt_lazytime, "lazytime"},
1338         {Opt_nolazytime, "nolazytime"},
1339         {Opt_nodelalloc, "nodelalloc"},
1340         {Opt_removed, "mblk_io_submit"},
1341         {Opt_removed, "nomblk_io_submit"},
1342         {Opt_block_validity, "block_validity"},
1343         {Opt_noblock_validity, "noblock_validity"},
1344         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1345         {Opt_journal_ioprio, "journal_ioprio=%u"},
1346         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1347         {Opt_auto_da_alloc, "auto_da_alloc"},
1348         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1349         {Opt_dioread_nolock, "dioread_nolock"},
1350         {Opt_dioread_lock, "dioread_lock"},
1351         {Opt_discard, "discard"},
1352         {Opt_nodiscard, "nodiscard"},
1353         {Opt_init_itable, "init_itable=%u"},
1354         {Opt_init_itable, "init_itable"},
1355         {Opt_noinit_itable, "noinit_itable"},
1356         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1357         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1358         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1359         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1360         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1361         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1362         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1363         {Opt_err, NULL},
1364 };
1365
1366 static ext4_fsblk_t get_sb_block(void **data)
1367 {
1368         ext4_fsblk_t    sb_block;
1369         char            *options = (char *) *data;
1370
1371         if (!options || strncmp(options, "sb=", 3) != 0)
1372                 return 1;       /* Default location */
1373
1374         options += 3;
1375         /* TODO: use simple_strtoll with >32bit ext4 */
1376         sb_block = simple_strtoul(options, &options, 0);
1377         if (*options && *options != ',') {
1378                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1379                        (char *) *data);
1380                 return 1;
1381         }
1382         if (*options == ',')
1383                 options++;
1384         *data = (void *) options;
1385
1386         return sb_block;
1387 }
1388
1389 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1390 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1391         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1392
1393 #ifdef CONFIG_QUOTA
1394 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1395 {
1396         struct ext4_sb_info *sbi = EXT4_SB(sb);
1397         char *qname;
1398         int ret = -1;
1399
1400         if (sb_any_quota_loaded(sb) &&
1401                 !sbi->s_qf_names[qtype]) {
1402                 ext4_msg(sb, KERN_ERR,
1403                         "Cannot change journaled "
1404                         "quota options when quota turned on");
1405                 return -1;
1406         }
1407         if (ext4_has_feature_quota(sb)) {
1408                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1409                          "ignored when QUOTA feature is enabled");
1410                 return 1;
1411         }
1412         qname = match_strdup(args);
1413         if (!qname) {
1414                 ext4_msg(sb, KERN_ERR,
1415                         "Not enough memory for storing quotafile name");
1416                 return -1;
1417         }
1418         if (sbi->s_qf_names[qtype]) {
1419                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1420                         ret = 1;
1421                 else
1422                         ext4_msg(sb, KERN_ERR,
1423                                  "%s quota file already specified",
1424                                  QTYPE2NAME(qtype));
1425                 goto errout;
1426         }
1427         if (strchr(qname, '/')) {
1428                 ext4_msg(sb, KERN_ERR,
1429                         "quotafile must be on filesystem root");
1430                 goto errout;
1431         }
1432         sbi->s_qf_names[qtype] = qname;
1433         set_opt(sb, QUOTA);
1434         return 1;
1435 errout:
1436         kfree(qname);
1437         return ret;
1438 }
1439
1440 static int clear_qf_name(struct super_block *sb, int qtype)
1441 {
1442
1443         struct ext4_sb_info *sbi = EXT4_SB(sb);
1444
1445         if (sb_any_quota_loaded(sb) &&
1446                 sbi->s_qf_names[qtype]) {
1447                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1448                         " when quota turned on");
1449                 return -1;
1450         }
1451         kfree(sbi->s_qf_names[qtype]);
1452         sbi->s_qf_names[qtype] = NULL;
1453         return 1;
1454 }
1455 #endif
1456
1457 #define MOPT_SET        0x0001
1458 #define MOPT_CLEAR      0x0002
1459 #define MOPT_NOSUPPORT  0x0004
1460 #define MOPT_EXPLICIT   0x0008
1461 #define MOPT_CLEAR_ERR  0x0010
1462 #define MOPT_GTE0       0x0020
1463 #ifdef CONFIG_QUOTA
1464 #define MOPT_Q          0
1465 #define MOPT_QFMT       0x0040
1466 #else
1467 #define MOPT_Q          MOPT_NOSUPPORT
1468 #define MOPT_QFMT       MOPT_NOSUPPORT
1469 #endif
1470 #define MOPT_DATAJ      0x0080
1471 #define MOPT_NO_EXT2    0x0100
1472 #define MOPT_NO_EXT3    0x0200
1473 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1474 #define MOPT_STRING     0x0400
1475
1476 static const struct mount_opts {
1477         int     token;
1478         int     mount_opt;
1479         int     flags;
1480 } ext4_mount_opts[] = {
1481         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1482         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1483         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1484         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1485         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1486         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1487         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1488          MOPT_EXT4_ONLY | MOPT_SET},
1489         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1490          MOPT_EXT4_ONLY | MOPT_CLEAR},
1491         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1492         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1493         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1494          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1495         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1496          MOPT_EXT4_ONLY | MOPT_CLEAR},
1497         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1498          MOPT_EXT4_ONLY | MOPT_CLEAR},
1499         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1500          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1501         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1502                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1503          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1504         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1505         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1506         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1507         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1508         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1509          MOPT_NO_EXT2},
1510         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1511          MOPT_NO_EXT2},
1512         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1513         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1514         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1515         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1516         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1517         {Opt_commit, 0, MOPT_GTE0},
1518         {Opt_max_batch_time, 0, MOPT_GTE0},
1519         {Opt_min_batch_time, 0, MOPT_GTE0},
1520         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1521         {Opt_init_itable, 0, MOPT_GTE0},
1522         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1523         {Opt_stripe, 0, MOPT_GTE0},
1524         {Opt_resuid, 0, MOPT_GTE0},
1525         {Opt_resgid, 0, MOPT_GTE0},
1526         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1527         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1528         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1529         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1530         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1531         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1532          MOPT_NO_EXT2 | MOPT_DATAJ},
1533         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1534         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1535 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1536         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1537         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1538 #else
1539         {Opt_acl, 0, MOPT_NOSUPPORT},
1540         {Opt_noacl, 0, MOPT_NOSUPPORT},
1541 #endif
1542         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1543         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1544         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1545         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1546                                                         MOPT_SET | MOPT_Q},
1547         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1548                                                         MOPT_SET | MOPT_Q},
1549         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1550                        EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1551         {Opt_usrjquota, 0, MOPT_Q},
1552         {Opt_grpjquota, 0, MOPT_Q},
1553         {Opt_offusrjquota, 0, MOPT_Q},
1554         {Opt_offgrpjquota, 0, MOPT_Q},
1555         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1556         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1557         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1558         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1559         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1560         {Opt_err, 0, 0}
1561 };
1562
1563 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1564                             substring_t *args, unsigned long *journal_devnum,
1565                             unsigned int *journal_ioprio, int is_remount)
1566 {
1567         struct ext4_sb_info *sbi = EXT4_SB(sb);
1568         const struct mount_opts *m;
1569         kuid_t uid;
1570         kgid_t gid;
1571         int arg = 0;
1572
1573 #ifdef CONFIG_QUOTA
1574         if (token == Opt_usrjquota)
1575                 return set_qf_name(sb, USRQUOTA, &args[0]);
1576         else if (token == Opt_grpjquota)
1577                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1578         else if (token == Opt_offusrjquota)
1579                 return clear_qf_name(sb, USRQUOTA);
1580         else if (token == Opt_offgrpjquota)
1581                 return clear_qf_name(sb, GRPQUOTA);
1582 #endif
1583         switch (token) {
1584         case Opt_noacl:
1585         case Opt_nouser_xattr:
1586                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1587                 break;
1588         case Opt_sb:
1589                 return 1;       /* handled by get_sb_block() */
1590         case Opt_removed:
1591                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1592                 return 1;
1593         case Opt_abort:
1594                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1595                 return 1;
1596         case Opt_i_version:
1597                 sb->s_flags |= MS_I_VERSION;
1598                 return 1;
1599         case Opt_lazytime:
1600                 sb->s_flags |= MS_LAZYTIME;
1601                 return 1;
1602         case Opt_nolazytime:
1603                 sb->s_flags &= ~MS_LAZYTIME;
1604                 return 1;
1605         }
1606
1607         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1608                 if (token == m->token)
1609                         break;
1610
1611         if (m->token == Opt_err) {
1612                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1613                          "or missing value", opt);
1614                 return -1;
1615         }
1616
1617         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1618                 ext4_msg(sb, KERN_ERR,
1619                          "Mount option \"%s\" incompatible with ext2", opt);
1620                 return -1;
1621         }
1622         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1623                 ext4_msg(sb, KERN_ERR,
1624                          "Mount option \"%s\" incompatible with ext3", opt);
1625                 return -1;
1626         }
1627
1628         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1629                 return -1;
1630         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1631                 return -1;
1632         if (m->flags & MOPT_EXPLICIT) {
1633                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1634                         set_opt2(sb, EXPLICIT_DELALLOC);
1635                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1636                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1637                 } else
1638                         return -1;
1639         }
1640         if (m->flags & MOPT_CLEAR_ERR)
1641                 clear_opt(sb, ERRORS_MASK);
1642         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1643                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1644                          "options when quota turned on");
1645                 return -1;
1646         }
1647
1648         if (m->flags & MOPT_NOSUPPORT) {
1649                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1650         } else if (token == Opt_commit) {
1651                 if (arg == 0)
1652                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1653                 sbi->s_commit_interval = HZ * arg;
1654         } else if (token == Opt_max_batch_time) {
1655                 sbi->s_max_batch_time = arg;
1656         } else if (token == Opt_min_batch_time) {
1657                 sbi->s_min_batch_time = arg;
1658         } else if (token == Opt_inode_readahead_blks) {
1659                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1660                         ext4_msg(sb, KERN_ERR,
1661                                  "EXT4-fs: inode_readahead_blks must be "
1662                                  "0 or a power of 2 smaller than 2^31");
1663                         return -1;
1664                 }
1665                 sbi->s_inode_readahead_blks = arg;
1666         } else if (token == Opt_init_itable) {
1667                 set_opt(sb, INIT_INODE_TABLE);
1668                 if (!args->from)
1669                         arg = EXT4_DEF_LI_WAIT_MULT;
1670                 sbi->s_li_wait_mult = arg;
1671         } else if (token == Opt_max_dir_size_kb) {
1672                 sbi->s_max_dir_size_kb = arg;
1673         } else if (token == Opt_stripe) {
1674                 sbi->s_stripe = arg;
1675         } else if (token == Opt_resuid) {
1676                 uid = make_kuid(current_user_ns(), arg);
1677                 if (!uid_valid(uid)) {
1678                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1679                         return -1;
1680                 }
1681                 sbi->s_resuid = uid;
1682         } else if (token == Opt_resgid) {
1683                 gid = make_kgid(current_user_ns(), arg);
1684                 if (!gid_valid(gid)) {
1685                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1686                         return -1;
1687                 }
1688                 sbi->s_resgid = gid;
1689         } else if (token == Opt_journal_dev) {
1690                 if (is_remount) {
1691                         ext4_msg(sb, KERN_ERR,
1692                                  "Cannot specify journal on remount");
1693                         return -1;
1694                 }
1695                 *journal_devnum = arg;
1696         } else if (token == Opt_journal_path) {
1697                 char *journal_path;
1698                 struct inode *journal_inode;
1699                 struct path path;
1700                 int error;
1701
1702                 if (is_remount) {
1703                         ext4_msg(sb, KERN_ERR,
1704                                  "Cannot specify journal on remount");
1705                         return -1;
1706                 }
1707                 journal_path = match_strdup(&args[0]);
1708                 if (!journal_path) {
1709                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1710                                 "journal device string");
1711                         return -1;
1712                 }
1713
1714                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1715                 if (error) {
1716                         ext4_msg(sb, KERN_ERR, "error: could not find "
1717                                 "journal device path: error %d", error);
1718                         kfree(journal_path);
1719                         return -1;
1720                 }
1721
1722                 journal_inode = d_inode(path.dentry);
1723                 if (!S_ISBLK(journal_inode->i_mode)) {
1724                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1725                                 "is not a block device", journal_path);
1726                         path_put(&path);
1727                         kfree(journal_path);
1728                         return -1;
1729                 }
1730
1731                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1732                 path_put(&path);
1733                 kfree(journal_path);
1734         } else if (token == Opt_journal_ioprio) {
1735                 if (arg > 7) {
1736                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1737                                  " (must be 0-7)");
1738                         return -1;
1739                 }
1740                 *journal_ioprio =
1741                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1742         } else if (token == Opt_test_dummy_encryption) {
1743 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1744                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1745                 ext4_msg(sb, KERN_WARNING,
1746                          "Test dummy encryption mode enabled");
1747 #else
1748                 ext4_msg(sb, KERN_WARNING,
1749                          "Test dummy encryption mount option ignored");
1750 #endif
1751         } else if (m->flags & MOPT_DATAJ) {
1752                 if (is_remount) {
1753                         if (!sbi->s_journal)
1754                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1755                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1756                                 ext4_msg(sb, KERN_ERR,
1757                                          "Cannot change data mode on remount");
1758                                 return -1;
1759                         }
1760                 } else {
1761                         clear_opt(sb, DATA_FLAGS);
1762                         sbi->s_mount_opt |= m->mount_opt;
1763                 }
1764 #ifdef CONFIG_QUOTA
1765         } else if (m->flags & MOPT_QFMT) {
1766                 if (sb_any_quota_loaded(sb) &&
1767                     sbi->s_jquota_fmt != m->mount_opt) {
1768                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1769                                  "quota options when quota turned on");
1770                         return -1;
1771                 }
1772                 if (ext4_has_feature_quota(sb)) {
1773                         ext4_msg(sb, KERN_INFO,
1774                                  "Quota format mount options ignored "
1775                                  "when QUOTA feature is enabled");
1776                         return 1;
1777                 }
1778                 sbi->s_jquota_fmt = m->mount_opt;
1779 #endif
1780         } else if (token == Opt_dax) {
1781 #ifdef CONFIG_FS_DAX
1782                 ext4_msg(sb, KERN_WARNING,
1783                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1784                         sbi->s_mount_opt |= m->mount_opt;
1785 #else
1786                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1787                 return -1;
1788 #endif
1789         } else if (token == Opt_data_err_abort) {
1790                 sbi->s_mount_opt |= m->mount_opt;
1791         } else if (token == Opt_data_err_ignore) {
1792                 sbi->s_mount_opt &= ~m->mount_opt;
1793         } else {
1794                 if (!args->from)
1795                         arg = 1;
1796                 if (m->flags & MOPT_CLEAR)
1797                         arg = !arg;
1798                 else if (unlikely(!(m->flags & MOPT_SET))) {
1799                         ext4_msg(sb, KERN_WARNING,
1800                                  "buggy handling of option %s", opt);
1801                         WARN_ON(1);
1802                         return -1;
1803                 }
1804                 if (arg != 0)
1805                         sbi->s_mount_opt |= m->mount_opt;
1806                 else
1807                         sbi->s_mount_opt &= ~m->mount_opt;
1808         }
1809         return 1;
1810 }
1811
1812 static int parse_options(char *options, struct super_block *sb,
1813                          unsigned long *journal_devnum,
1814                          unsigned int *journal_ioprio,
1815                          int is_remount)
1816 {
1817         struct ext4_sb_info *sbi = EXT4_SB(sb);
1818         char *p;
1819         substring_t args[MAX_OPT_ARGS];
1820         int token;
1821
1822         if (!options)
1823                 return 1;
1824
1825         while ((p = strsep(&options, ",")) != NULL) {
1826                 if (!*p)
1827                         continue;
1828                 /*
1829                  * Initialize args struct so we know whether arg was
1830                  * found; some options take optional arguments.
1831                  */
1832                 args[0].to = args[0].from = NULL;
1833                 token = match_token(p, tokens, args);
1834                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1835                                      journal_ioprio, is_remount) < 0)
1836                         return 0;
1837         }
1838 #ifdef CONFIG_QUOTA
1839         if (ext4_has_feature_quota(sb) &&
1840             (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1841                 ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1842                          "mount options ignored.");
1843                 clear_opt(sb, USRQUOTA);
1844                 clear_opt(sb, GRPQUOTA);
1845         } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1846                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1847                         clear_opt(sb, USRQUOTA);
1848
1849                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1850                         clear_opt(sb, GRPQUOTA);
1851
1852                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1853                         ext4_msg(sb, KERN_ERR, "old and new quota "
1854                                         "format mixing");
1855                         return 0;
1856                 }
1857
1858                 if (!sbi->s_jquota_fmt) {
1859                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1860                                         "not specified");
1861                         return 0;
1862                 }
1863         }
1864 #endif
1865         if (test_opt(sb, DIOREAD_NOLOCK)) {
1866                 int blocksize =
1867                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1868
1869                 if (blocksize < PAGE_SIZE) {
1870                         ext4_msg(sb, KERN_ERR, "can't mount with "
1871                                  "dioread_nolock if block size != PAGE_SIZE");
1872                         return 0;
1873                 }
1874         }
1875         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1876             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1877                 ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1878                          "in data=ordered mode");
1879                 return 0;
1880         }
1881         return 1;
1882 }
1883
1884 static inline void ext4_show_quota_options(struct seq_file *seq,
1885                                            struct super_block *sb)
1886 {
1887 #if defined(CONFIG_QUOTA)
1888         struct ext4_sb_info *sbi = EXT4_SB(sb);
1889
1890         if (sbi->s_jquota_fmt) {
1891                 char *fmtname = "";
1892
1893                 switch (sbi->s_jquota_fmt) {
1894                 case QFMT_VFS_OLD:
1895                         fmtname = "vfsold";
1896                         break;
1897                 case QFMT_VFS_V0:
1898                         fmtname = "vfsv0";
1899                         break;
1900                 case QFMT_VFS_V1:
1901                         fmtname = "vfsv1";
1902                         break;
1903                 }
1904                 seq_printf(seq, ",jqfmt=%s", fmtname);
1905         }
1906
1907         if (sbi->s_qf_names[USRQUOTA])
1908                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1909
1910         if (sbi->s_qf_names[GRPQUOTA])
1911                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1912 #endif
1913 }
1914
1915 static const char *token2str(int token)
1916 {
1917         const struct match_token *t;
1918
1919         for (t = tokens; t->token != Opt_err; t++)
1920                 if (t->token == token && !strchr(t->pattern, '='))
1921                         break;
1922         return t->pattern;
1923 }
1924
1925 /*
1926  * Show an option if
1927  *  - it's set to a non-default value OR
1928  *  - if the per-sb default is different from the global default
1929  */
1930 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1931                               int nodefs)
1932 {
1933         struct ext4_sb_info *sbi = EXT4_SB(sb);
1934         struct ext4_super_block *es = sbi->s_es;
1935         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1936         const struct mount_opts *m;
1937         char sep = nodefs ? '\n' : ',';
1938
1939 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1940 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1941
1942         if (sbi->s_sb_block != 1)
1943                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1944
1945         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1946                 int want_set = m->flags & MOPT_SET;
1947                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1948                     (m->flags & MOPT_CLEAR_ERR))
1949                         continue;
1950                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1951                         continue; /* skip if same as the default */
1952                 if ((want_set &&
1953                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1954                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1955                         continue; /* select Opt_noFoo vs Opt_Foo */
1956                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1957         }
1958
1959         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1960             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1961                 SEQ_OPTS_PRINT("resuid=%u",
1962                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1963         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1964             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1965                 SEQ_OPTS_PRINT("resgid=%u",
1966                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1967         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1968         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1969                 SEQ_OPTS_PUTS("errors=remount-ro");
1970         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1971                 SEQ_OPTS_PUTS("errors=continue");
1972         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1973                 SEQ_OPTS_PUTS("errors=panic");
1974         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1975                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1976         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1977                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1978         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1979                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1980         if (sb->s_flags & MS_I_VERSION)
1981                 SEQ_OPTS_PUTS("i_version");
1982         if (nodefs || sbi->s_stripe)
1983                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1984         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1985                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1986                         SEQ_OPTS_PUTS("data=journal");
1987                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1988                         SEQ_OPTS_PUTS("data=ordered");
1989                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1990                         SEQ_OPTS_PUTS("data=writeback");
1991         }
1992         if (nodefs ||
1993             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1994                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1995                                sbi->s_inode_readahead_blks);
1996
1997         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1998                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1999                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2000         if (nodefs || sbi->s_max_dir_size_kb)
2001                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2002         if (test_opt(sb, DATA_ERR_ABORT))
2003                 SEQ_OPTS_PUTS("data_err=abort");
2004
2005         ext4_show_quota_options(seq, sb);
2006         return 0;
2007 }
2008
2009 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2010 {
2011         return _ext4_show_options(seq, root->d_sb, 0);
2012 }
2013
2014 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2015 {
2016         struct super_block *sb = seq->private;
2017         int rc;
2018
2019         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2020         rc = _ext4_show_options(seq, sb, 1);
2021         seq_puts(seq, "\n");
2022         return rc;
2023 }
2024
2025 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2026                             int read_only)
2027 {
2028         struct ext4_sb_info *sbi = EXT4_SB(sb);
2029         int res = 0;
2030
2031         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2032                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2033                          "forcing read-only mode");
2034                 res = MS_RDONLY;
2035         }
2036         if (read_only)
2037                 goto done;
2038         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2039                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2040                          "running e2fsck is recommended");
2041         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2042                 ext4_msg(sb, KERN_WARNING,
2043                          "warning: mounting fs with errors, "
2044                          "running e2fsck is recommended");
2045         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2046                  le16_to_cpu(es->s_mnt_count) >=
2047                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2048                 ext4_msg(sb, KERN_WARNING,
2049                          "warning: maximal mount count reached, "
2050                          "running e2fsck is recommended");
2051         else if (le32_to_cpu(es->s_checkinterval) &&
2052                 (le32_to_cpu(es->s_lastcheck) +
2053                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2054                 ext4_msg(sb, KERN_WARNING,
2055                          "warning: checktime reached, "
2056                          "running e2fsck is recommended");
2057         if (!sbi->s_journal)
2058                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2059         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2060                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2061         le16_add_cpu(&es->s_mnt_count, 1);
2062         es->s_mtime = cpu_to_le32(get_seconds());
2063         ext4_update_dynamic_rev(sb);
2064         if (sbi->s_journal)
2065                 ext4_set_feature_journal_needs_recovery(sb);
2066
2067         ext4_commit_super(sb, 1);
2068 done:
2069         if (test_opt(sb, DEBUG))
2070                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2071                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2072                         sb->s_blocksize,
2073                         sbi->s_groups_count,
2074                         EXT4_BLOCKS_PER_GROUP(sb),
2075                         EXT4_INODES_PER_GROUP(sb),
2076                         sbi->s_mount_opt, sbi->s_mount_opt2);
2077
2078         cleancache_init_fs(sb);
2079         return res;
2080 }
2081
2082 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2083 {
2084         struct ext4_sb_info *sbi = EXT4_SB(sb);
2085         struct flex_groups *new_groups;
2086         int size;
2087
2088         if (!sbi->s_log_groups_per_flex)
2089                 return 0;
2090
2091         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2092         if (size <= sbi->s_flex_groups_allocated)
2093                 return 0;
2094
2095         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2096         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2097         if (!new_groups) {
2098                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2099                          size / (int) sizeof(struct flex_groups));
2100                 return -ENOMEM;
2101         }
2102
2103         if (sbi->s_flex_groups) {
2104                 memcpy(new_groups, sbi->s_flex_groups,
2105                        (sbi->s_flex_groups_allocated *
2106                         sizeof(struct flex_groups)));
2107                 kvfree(sbi->s_flex_groups);
2108         }
2109         sbi->s_flex_groups = new_groups;
2110         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2111         return 0;
2112 }
2113
2114 static int ext4_fill_flex_info(struct super_block *sb)
2115 {
2116         struct ext4_sb_info *sbi = EXT4_SB(sb);
2117         struct ext4_group_desc *gdp = NULL;
2118         ext4_group_t flex_group;
2119         int i, err;
2120
2121         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2122         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2123                 sbi->s_log_groups_per_flex = 0;
2124                 return 1;
2125         }
2126
2127         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2128         if (err)
2129                 goto failed;
2130
2131         for (i = 0; i < sbi->s_groups_count; i++) {
2132                 gdp = ext4_get_group_desc(sb, i, NULL);
2133
2134                 flex_group = ext4_flex_group(sbi, i);
2135                 atomic_add(ext4_free_inodes_count(sb, gdp),
2136                            &sbi->s_flex_groups[flex_group].free_inodes);
2137                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2138                              &sbi->s_flex_groups[flex_group].free_clusters);
2139                 atomic_add(ext4_used_dirs_count(sb, gdp),
2140                            &sbi->s_flex_groups[flex_group].used_dirs);
2141         }
2142
2143         return 1;
2144 failed:
2145         return 0;
2146 }
2147
2148 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2149                                    struct ext4_group_desc *gdp)
2150 {
2151         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2152         __u16 crc = 0;
2153         __le32 le_group = cpu_to_le32(block_group);
2154         struct ext4_sb_info *sbi = EXT4_SB(sb);
2155
2156         if (ext4_has_metadata_csum(sbi->s_sb)) {
2157                 /* Use new metadata_csum algorithm */
2158                 __u32 csum32;
2159                 __u16 dummy_csum = 0;
2160
2161                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2162                                      sizeof(le_group));
2163                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2164                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2165                                      sizeof(dummy_csum));
2166                 offset += sizeof(dummy_csum);
2167                 if (offset < sbi->s_desc_size)
2168                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2169                                              sbi->s_desc_size - offset);
2170
2171                 crc = csum32 & 0xFFFF;
2172                 goto out;
2173         }
2174
2175         /* old crc16 code */
2176         if (!ext4_has_feature_gdt_csum(sb))
2177                 return 0;
2178
2179         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2180         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2181         crc = crc16(crc, (__u8 *)gdp, offset);
2182         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2183         /* for checksum of struct ext4_group_desc do the rest...*/
2184         if (ext4_has_feature_64bit(sb) &&
2185             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2186                 crc = crc16(crc, (__u8 *)gdp + offset,
2187                             le16_to_cpu(sbi->s_es->s_desc_size) -
2188                                 offset);
2189
2190 out:
2191         return cpu_to_le16(crc);
2192 }
2193
2194 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2195                                 struct ext4_group_desc *gdp)
2196 {
2197         if (ext4_has_group_desc_csum(sb) &&
2198             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2199                 return 0;
2200
2201         return 1;
2202 }
2203
2204 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2205                               struct ext4_group_desc *gdp)
2206 {
2207         if (!ext4_has_group_desc_csum(sb))
2208                 return;
2209         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2210 }
2211
2212 /* Called at mount-time, super-block is locked */
2213 static int ext4_check_descriptors(struct super_block *sb,
2214                                   ext4_group_t *first_not_zeroed)
2215 {
2216         struct ext4_sb_info *sbi = EXT4_SB(sb);
2217         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2218         ext4_fsblk_t last_block;
2219         ext4_fsblk_t block_bitmap;
2220         ext4_fsblk_t inode_bitmap;
2221         ext4_fsblk_t inode_table;
2222         int flexbg_flag = 0;
2223         ext4_group_t i, grp = sbi->s_groups_count;
2224
2225         if (ext4_has_feature_flex_bg(sb))
2226                 flexbg_flag = 1;
2227
2228         ext4_debug("Checking group descriptors");
2229
2230         for (i = 0; i < sbi->s_groups_count; i++) {
2231                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2232
2233                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2234                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2235                 else
2236                         last_block = first_block +
2237                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2238
2239                 if ((grp == sbi->s_groups_count) &&
2240                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2241                         grp = i;
2242
2243                 block_bitmap = ext4_block_bitmap(sb, gdp);
2244                 if (block_bitmap < first_block || block_bitmap > last_block) {
2245                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2246                                "Block bitmap for group %u not in group "
2247                                "(block %llu)!", i, block_bitmap);
2248                         return 0;
2249                 }
2250                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2251                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2252                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2253                                "Inode bitmap for group %u not in group "
2254                                "(block %llu)!", i, inode_bitmap);
2255                         return 0;
2256                 }
2257                 inode_table = ext4_inode_table(sb, gdp);
2258                 if (inode_table < first_block ||
2259                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2260                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2261                                "Inode table for group %u not in group "
2262                                "(block %llu)!", i, inode_table);
2263                         return 0;
2264                 }
2265                 ext4_lock_group(sb, i);
2266                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2267                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2268                                  "Checksum for group %u failed (%u!=%u)",
2269                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2270                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2271                         if (!(sb->s_flags & MS_RDONLY)) {
2272                                 ext4_unlock_group(sb, i);
2273                                 return 0;
2274                         }
2275                 }
2276                 ext4_unlock_group(sb, i);
2277                 if (!flexbg_flag)
2278                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2279         }
2280         if (NULL != first_not_zeroed)
2281                 *first_not_zeroed = grp;
2282         return 1;
2283 }
2284
2285 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2286  * the superblock) which were deleted from all directories, but held open by
2287  * a process at the time of a crash.  We walk the list and try to delete these
2288  * inodes at recovery time (only with a read-write filesystem).
2289  *
2290  * In order to keep the orphan inode chain consistent during traversal (in
2291  * case of crash during recovery), we link each inode into the superblock
2292  * orphan list_head and handle it the same way as an inode deletion during
2293  * normal operation (which journals the operations for us).
2294  *
2295  * We only do an iget() and an iput() on each inode, which is very safe if we
2296  * accidentally point at an in-use or already deleted inode.  The worst that
2297  * can happen in this case is that we get a "bit already cleared" message from
2298  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2299  * e2fsck was run on this filesystem, and it must have already done the orphan
2300  * inode cleanup for us, so we can safely abort without any further action.
2301  */
2302 static void ext4_orphan_cleanup(struct super_block *sb,
2303                                 struct ext4_super_block *es)
2304 {
2305         unsigned int s_flags = sb->s_flags;
2306         int nr_orphans = 0, nr_truncates = 0;
2307 #ifdef CONFIG_QUOTA
2308         int i;
2309 #endif
2310         if (!es->s_last_orphan) {
2311                 jbd_debug(4, "no orphan inodes to clean up\n");
2312                 return;
2313         }
2314
2315         if (bdev_read_only(sb->s_bdev)) {
2316                 ext4_msg(sb, KERN_ERR, "write access "
2317                         "unavailable, skipping orphan cleanup");
2318                 return;
2319         }
2320
2321         /* Check if feature set would not allow a r/w mount */
2322         if (!ext4_feature_set_ok(sb, 0)) {
2323                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2324                          "unknown ROCOMPAT features");
2325                 return;
2326         }
2327
2328         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2329                 /* don't clear list on RO mount w/ errors */
2330                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2331                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2332                                   "clearing orphan list.\n");
2333                         es->s_last_orphan = 0;
2334                 }
2335                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2336                 return;
2337         }
2338
2339         if (s_flags & MS_RDONLY) {
2340                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2341                 sb->s_flags &= ~MS_RDONLY;
2342         }
2343 #ifdef CONFIG_QUOTA
2344         /* Needed for iput() to work correctly and not trash data */
2345         sb->s_flags |= MS_ACTIVE;
2346         /* Turn on quotas so that they are updated correctly */
2347         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2348                 if (EXT4_SB(sb)->s_qf_names[i]) {
2349                         int ret = ext4_quota_on_mount(sb, i);
2350                         if (ret < 0)
2351                                 ext4_msg(sb, KERN_ERR,
2352                                         "Cannot turn on journaled "
2353                                         "quota: error %d", ret);
2354                 }
2355         }
2356 #endif
2357
2358         while (es->s_last_orphan) {
2359                 struct inode *inode;
2360
2361                 /*
2362                  * We may have encountered an error during cleanup; if
2363                  * so, skip the rest.
2364                  */
2365                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2366                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2367                         es->s_last_orphan = 0;
2368                         break;
2369                 }
2370
2371                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2372                 if (IS_ERR(inode)) {
2373                         es->s_last_orphan = 0;
2374                         break;
2375                 }
2376
2377                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2378                 dquot_initialize(inode);
2379                 if (inode->i_nlink) {
2380                         if (test_opt(sb, DEBUG))
2381                                 ext4_msg(sb, KERN_DEBUG,
2382                                         "%s: truncating inode %lu to %lld bytes",
2383                                         __func__, inode->i_ino, inode->i_size);
2384                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2385                                   inode->i_ino, inode->i_size);
2386                         inode_lock(inode);
2387                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2388                         ext4_truncate(inode);
2389                         inode_unlock(inode);
2390                         nr_truncates++;
2391                 } else {
2392                         if (test_opt(sb, DEBUG))
2393                                 ext4_msg(sb, KERN_DEBUG,
2394                                         "%s: deleting unreferenced inode %lu",
2395                                         __func__, inode->i_ino);
2396                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2397                                   inode->i_ino);
2398                         nr_orphans++;
2399                 }
2400                 iput(inode);  /* The delete magic happens here! */
2401         }
2402
2403 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2404
2405         if (nr_orphans)
2406                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2407                        PLURAL(nr_orphans));
2408         if (nr_truncates)
2409                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2410                        PLURAL(nr_truncates));
2411 #ifdef CONFIG_QUOTA
2412         /* Turn quotas off */
2413         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2414                 if (sb_dqopt(sb)->files[i])
2415                         dquot_quota_off(sb, i);
2416         }
2417 #endif
2418         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2419 }
2420
2421 /*
2422  * Maximal extent format file size.
2423  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2424  * extent format containers, within a sector_t, and within i_blocks
2425  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2426  * so that won't be a limiting factor.
2427  *
2428  * However there is other limiting factor. We do store extents in the form
2429  * of starting block and length, hence the resulting length of the extent
2430  * covering maximum file size must fit into on-disk format containers as
2431  * well. Given that length is always by 1 unit bigger than max unit (because
2432  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2433  *
2434  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2435  */
2436 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2437 {
2438         loff_t res;
2439         loff_t upper_limit = MAX_LFS_FILESIZE;
2440
2441         /* small i_blocks in vfs inode? */
2442         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2443                 /*
2444                  * CONFIG_LBDAF is not enabled implies the inode
2445                  * i_block represent total blocks in 512 bytes
2446                  * 32 == size of vfs inode i_blocks * 8
2447                  */
2448                 upper_limit = (1LL << 32) - 1;
2449
2450                 /* total blocks in file system block size */
2451                 upper_limit >>= (blkbits - 9);
2452                 upper_limit <<= blkbits;
2453         }
2454
2455         /*
2456          * 32-bit extent-start container, ee_block. We lower the maxbytes
2457          * by one fs block, so ee_len can cover the extent of maximum file
2458          * size
2459          */
2460         res = (1LL << 32) - 1;
2461         res <<= blkbits;
2462
2463         /* Sanity check against vm- & vfs- imposed limits */
2464         if (res > upper_limit)
2465                 res = upper_limit;
2466
2467         return res;
2468 }
2469
2470 /*
2471  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2472  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2473  * We need to be 1 filesystem block less than the 2^48 sector limit.
2474  */
2475 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2476 {
2477         loff_t res = EXT4_NDIR_BLOCKS;
2478         int meta_blocks;
2479         loff_t upper_limit;
2480         /* This is calculated to be the largest file size for a dense, block
2481          * mapped file such that the file's total number of 512-byte sectors,
2482          * including data and all indirect blocks, does not exceed (2^48 - 1).
2483          *
2484          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2485          * number of 512-byte sectors of the file.
2486          */
2487
2488         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2489                 /*
2490                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2491                  * the inode i_block field represents total file blocks in
2492                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2493                  */
2494                 upper_limit = (1LL << 32) - 1;
2495
2496                 /* total blocks in file system block size */
2497                 upper_limit >>= (bits - 9);
2498
2499         } else {
2500                 /*
2501                  * We use 48 bit ext4_inode i_blocks
2502                  * With EXT4_HUGE_FILE_FL set the i_blocks
2503                  * represent total number of blocks in
2504                  * file system block size
2505                  */
2506                 upper_limit = (1LL << 48) - 1;
2507
2508         }
2509
2510         /* indirect blocks */
2511         meta_blocks = 1;
2512         /* double indirect blocks */
2513         meta_blocks += 1 + (1LL << (bits-2));
2514         /* tripple indirect blocks */
2515         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2516
2517         upper_limit -= meta_blocks;
2518         upper_limit <<= bits;
2519
2520         res += 1LL << (bits-2);
2521         res += 1LL << (2*(bits-2));
2522         res += 1LL << (3*(bits-2));
2523         res <<= bits;
2524         if (res > upper_limit)
2525                 res = upper_limit;
2526
2527         if (res > MAX_LFS_FILESIZE)
2528                 res = MAX_LFS_FILESIZE;
2529
2530         return res;
2531 }
2532
2533 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2534                                    ext4_fsblk_t logical_sb_block, int nr)
2535 {
2536         struct ext4_sb_info *sbi = EXT4_SB(sb);
2537         ext4_group_t bg, first_meta_bg;
2538         int has_super = 0;
2539
2540         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2541
2542         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2543                 return logical_sb_block + nr + 1;
2544         bg = sbi->s_desc_per_block * nr;
2545         if (ext4_bg_has_super(sb, bg))
2546                 has_super = 1;
2547
2548         /*
2549          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2550          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2551          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2552          * compensate.
2553          */
2554         if (sb->s_blocksize == 1024 && nr == 0 &&
2555             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2556                 has_super++;
2557
2558         return (has_super + ext4_group_first_block_no(sb, bg));
2559 }
2560
2561 /**
2562  * ext4_get_stripe_size: Get the stripe size.
2563  * @sbi: In memory super block info
2564  *
2565  * If we have specified it via mount option, then
2566  * use the mount option value. If the value specified at mount time is
2567  * greater than the blocks per group use the super block value.
2568  * If the super block value is greater than blocks per group return 0.
2569  * Allocator needs it be less than blocks per group.
2570  *
2571  */
2572 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2573 {
2574         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2575         unsigned long stripe_width =
2576                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2577         int ret;
2578
2579         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2580                 ret = sbi->s_stripe;
2581         else if (stripe_width <= sbi->s_blocks_per_group)
2582                 ret = stripe_width;
2583         else if (stride <= sbi->s_blocks_per_group)
2584                 ret = stride;
2585         else
2586                 ret = 0;
2587
2588         /*
2589          * If the stripe width is 1, this makes no sense and
2590          * we set it to 0 to turn off stripe handling code.
2591          */
2592         if (ret <= 1)
2593                 ret = 0;
2594
2595         return ret;
2596 }
2597
2598 /*
2599  * Check whether this filesystem can be mounted based on
2600  * the features present and the RDONLY/RDWR mount requested.
2601  * Returns 1 if this filesystem can be mounted as requested,
2602  * 0 if it cannot be.
2603  */
2604 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2605 {
2606         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2607                 ext4_msg(sb, KERN_ERR,
2608                         "Couldn't mount because of "
2609                         "unsupported optional features (%x)",
2610                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2611                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2612                 return 0;
2613         }
2614
2615         if (readonly)
2616                 return 1;
2617
2618         if (ext4_has_feature_readonly(sb)) {
2619                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2620                 sb->s_flags |= MS_RDONLY;
2621                 return 1;
2622         }
2623
2624         /* Check that feature set is OK for a read-write mount */
2625         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2626                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2627                          "unsupported optional features (%x)",
2628                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2629                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2630                 return 0;
2631         }
2632         /*
2633          * Large file size enabled file system can only be mounted
2634          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2635          */
2636         if (ext4_has_feature_huge_file(sb)) {
2637                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2638                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2639                                  "cannot be mounted RDWR without "
2640                                  "CONFIG_LBDAF");
2641                         return 0;
2642                 }
2643         }
2644         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2645                 ext4_msg(sb, KERN_ERR,
2646                          "Can't support bigalloc feature without "
2647                          "extents feature\n");
2648                 return 0;
2649         }
2650
2651 #ifndef CONFIG_QUOTA
2652         if (ext4_has_feature_quota(sb) && !readonly) {
2653                 ext4_msg(sb, KERN_ERR,
2654                          "Filesystem with quota feature cannot be mounted RDWR "
2655                          "without CONFIG_QUOTA");
2656                 return 0;
2657         }
2658         if (ext4_has_feature_project(sb) && !readonly) {
2659                 ext4_msg(sb, KERN_ERR,
2660                          "Filesystem with project quota feature cannot be mounted RDWR "
2661                          "without CONFIG_QUOTA");
2662                 return 0;
2663         }
2664 #endif  /* CONFIG_QUOTA */
2665         return 1;
2666 }
2667
2668 /*
2669  * This function is called once a day if we have errors logged
2670  * on the file system
2671  */
2672 static void print_daily_error_info(unsigned long arg)
2673 {
2674         struct super_block *sb = (struct super_block *) arg;
2675         struct ext4_sb_info *sbi;
2676         struct ext4_super_block *es;
2677
2678         sbi = EXT4_SB(sb);
2679         es = sbi->s_es;
2680
2681         if (es->s_error_count)
2682                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2683                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2684                          le32_to_cpu(es->s_error_count));
2685         if (es->s_first_error_time) {
2686                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2687                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2688                        (int) sizeof(es->s_first_error_func),
2689                        es->s_first_error_func,
2690                        le32_to_cpu(es->s_first_error_line));
2691                 if (es->s_first_error_ino)
2692                         printk(": inode %u",
2693                                le32_to_cpu(es->s_first_error_ino));
2694                 if (es->s_first_error_block)
2695                         printk(": block %llu", (unsigned long long)
2696                                le64_to_cpu(es->s_first_error_block));
2697                 printk("\n");
2698         }
2699         if (es->s_last_error_time) {
2700                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2701                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2702                        (int) sizeof(es->s_last_error_func),
2703                        es->s_last_error_func,
2704                        le32_to_cpu(es->s_last_error_line));
2705                 if (es->s_last_error_ino)
2706                         printk(": inode %u",
2707                                le32_to_cpu(es->s_last_error_ino));
2708                 if (es->s_last_error_block)
2709                         printk(": block %llu", (unsigned long long)
2710                                le64_to_cpu(es->s_last_error_block));
2711                 printk("\n");
2712         }
2713         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2714 }
2715
2716 /* Find next suitable group and run ext4_init_inode_table */
2717 static int ext4_run_li_request(struct ext4_li_request *elr)
2718 {
2719         struct ext4_group_desc *gdp = NULL;
2720         ext4_group_t group, ngroups;
2721         struct super_block *sb;
2722         unsigned long timeout = 0;
2723         int ret = 0;
2724
2725         sb = elr->lr_super;
2726         ngroups = EXT4_SB(sb)->s_groups_count;
2727
2728         sb_start_write(sb);
2729         for (group = elr->lr_next_group; group < ngroups; group++) {
2730                 gdp = ext4_get_group_desc(sb, group, NULL);
2731                 if (!gdp) {
2732                         ret = 1;
2733                         break;
2734                 }
2735
2736                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2737                         break;
2738         }
2739
2740         if (group >= ngroups)
2741                 ret = 1;
2742
2743         if (!ret) {
2744                 timeout = jiffies;
2745                 ret = ext4_init_inode_table(sb, group,
2746                                             elr->lr_timeout ? 0 : 1);
2747                 if (elr->lr_timeout == 0) {
2748                         timeout = (jiffies - timeout) *
2749                                   elr->lr_sbi->s_li_wait_mult;
2750                         elr->lr_timeout = timeout;
2751                 }
2752                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2753                 elr->lr_next_group = group + 1;
2754         }
2755         sb_end_write(sb);
2756
2757         return ret;
2758 }
2759
2760 /*
2761  * Remove lr_request from the list_request and free the
2762  * request structure. Should be called with li_list_mtx held
2763  */
2764 static void ext4_remove_li_request(struct ext4_li_request *elr)
2765 {
2766         struct ext4_sb_info *sbi;
2767
2768         if (!elr)
2769                 return;
2770
2771         sbi = elr->lr_sbi;
2772
2773         list_del(&elr->lr_request);
2774         sbi->s_li_request = NULL;
2775         kfree(elr);
2776 }
2777
2778 static void ext4_unregister_li_request(struct super_block *sb)
2779 {
2780         mutex_lock(&ext4_li_mtx);
2781         if (!ext4_li_info) {
2782                 mutex_unlock(&ext4_li_mtx);
2783                 return;
2784         }
2785
2786         mutex_lock(&ext4_li_info->li_list_mtx);
2787         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2788         mutex_unlock(&ext4_li_info->li_list_mtx);
2789         mutex_unlock(&ext4_li_mtx);
2790 }
2791
2792 static struct task_struct *ext4_lazyinit_task;
2793
2794 /*
2795  * This is the function where ext4lazyinit thread lives. It walks
2796  * through the request list searching for next scheduled filesystem.
2797  * When such a fs is found, run the lazy initialization request
2798  * (ext4_rn_li_request) and keep track of the time spend in this
2799  * function. Based on that time we compute next schedule time of
2800  * the request. When walking through the list is complete, compute
2801  * next waking time and put itself into sleep.
2802  */
2803 static int ext4_lazyinit_thread(void *arg)
2804 {
2805         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2806         struct list_head *pos, *n;
2807         struct ext4_li_request *elr;
2808         unsigned long next_wakeup, cur;
2809
2810         BUG_ON(NULL == eli);
2811
2812 cont_thread:
2813         while (true) {
2814                 next_wakeup = MAX_JIFFY_OFFSET;
2815
2816                 mutex_lock(&eli->li_list_mtx);
2817                 if (list_empty(&eli->li_request_list)) {
2818                         mutex_unlock(&eli->li_list_mtx);
2819                         goto exit_thread;
2820                 }
2821
2822                 list_for_each_safe(pos, n, &eli->li_request_list) {
2823                         elr = list_entry(pos, struct ext4_li_request,
2824                                          lr_request);
2825
2826                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2827                                 if (ext4_run_li_request(elr) != 0) {
2828                                         /* error, remove the lazy_init job */
2829                                         ext4_remove_li_request(elr);
2830                                         continue;
2831                                 }
2832                         }
2833
2834                         if (time_before(elr->lr_next_sched, next_wakeup))
2835                                 next_wakeup = elr->lr_next_sched;
2836                 }
2837                 mutex_unlock(&eli->li_list_mtx);
2838
2839                 try_to_freeze();
2840
2841                 cur = jiffies;
2842                 if ((time_after_eq(cur, next_wakeup)) ||
2843                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2844                         cond_resched();
2845                         continue;
2846                 }
2847
2848                 schedule_timeout_interruptible(next_wakeup - cur);
2849
2850                 if (kthread_should_stop()) {
2851                         ext4_clear_request_list();
2852                         goto exit_thread;
2853                 }
2854         }
2855
2856 exit_thread:
2857         /*
2858          * It looks like the request list is empty, but we need
2859          * to check it under the li_list_mtx lock, to prevent any
2860          * additions into it, and of course we should lock ext4_li_mtx
2861          * to atomically free the list and ext4_li_info, because at
2862          * this point another ext4 filesystem could be registering
2863          * new one.
2864          */
2865         mutex_lock(&ext4_li_mtx);
2866         mutex_lock(&eli->li_list_mtx);
2867         if (!list_empty(&eli->li_request_list)) {
2868                 mutex_unlock(&eli->li_list_mtx);
2869                 mutex_unlock(&ext4_li_mtx);
2870                 goto cont_thread;
2871         }
2872         mutex_unlock(&eli->li_list_mtx);
2873         kfree(ext4_li_info);
2874         ext4_li_info = NULL;
2875         mutex_unlock(&ext4_li_mtx);
2876
2877         return 0;
2878 }
2879
2880 static void ext4_clear_request_list(void)
2881 {
2882         struct list_head *pos, *n;
2883         struct ext4_li_request *elr;
2884
2885         mutex_lock(&ext4_li_info->li_list_mtx);
2886         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2887                 elr = list_entry(pos, struct ext4_li_request,
2888                                  lr_request);
2889                 ext4_remove_li_request(elr);
2890         }
2891         mutex_unlock(&ext4_li_info->li_list_mtx);
2892 }
2893
2894 static int ext4_run_lazyinit_thread(void)
2895 {
2896         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2897                                          ext4_li_info, "ext4lazyinit");
2898         if (IS_ERR(ext4_lazyinit_task)) {
2899                 int err = PTR_ERR(ext4_lazyinit_task);
2900                 ext4_clear_request_list();
2901                 kfree(ext4_li_info);
2902                 ext4_li_info = NULL;
2903                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2904                                  "initialization thread\n",
2905                                  err);
2906                 return err;
2907         }
2908         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2909         return 0;
2910 }
2911
2912 /*
2913  * Check whether it make sense to run itable init. thread or not.
2914  * If there is at least one uninitialized inode table, return
2915  * corresponding group number, else the loop goes through all
2916  * groups and return total number of groups.
2917  */
2918 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2919 {
2920         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2921         struct ext4_group_desc *gdp = NULL;
2922
2923         for (group = 0; group < ngroups; group++) {
2924                 gdp = ext4_get_group_desc(sb, group, NULL);
2925                 if (!gdp)
2926                         continue;
2927
2928                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2929                         break;
2930         }
2931
2932         return group;
2933 }
2934
2935 static int ext4_li_info_new(void)
2936 {
2937         struct ext4_lazy_init *eli = NULL;
2938
2939         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2940         if (!eli)
2941                 return -ENOMEM;
2942
2943         INIT_LIST_HEAD(&eli->li_request_list);
2944         mutex_init(&eli->li_list_mtx);
2945
2946         eli->li_state |= EXT4_LAZYINIT_QUIT;
2947
2948         ext4_li_info = eli;
2949
2950         return 0;
2951 }
2952
2953 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2954                                             ext4_group_t start)
2955 {
2956         struct ext4_sb_info *sbi = EXT4_SB(sb);
2957         struct ext4_li_request *elr;
2958
2959         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2960         if (!elr)
2961                 return NULL;
2962
2963         elr->lr_super = sb;
2964         elr->lr_sbi = sbi;
2965         elr->lr_next_group = start;
2966
2967         /*
2968          * Randomize first schedule time of the request to
2969          * spread the inode table initialization requests
2970          * better.
2971          */
2972         elr->lr_next_sched = jiffies + (prandom_u32() %
2973                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2974         return elr;
2975 }
2976
2977 int ext4_register_li_request(struct super_block *sb,
2978                              ext4_group_t first_not_zeroed)
2979 {
2980         struct ext4_sb_info *sbi = EXT4_SB(sb);
2981         struct ext4_li_request *elr = NULL;
2982         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2983         int ret = 0;
2984
2985         mutex_lock(&ext4_li_mtx);
2986         if (sbi->s_li_request != NULL) {
2987                 /*
2988                  * Reset timeout so it can be computed again, because
2989                  * s_li_wait_mult might have changed.
2990                  */
2991                 sbi->s_li_request->lr_timeout = 0;
2992                 goto out;
2993         }
2994
2995         if (first_not_zeroed == ngroups ||
2996             (sb->s_flags & MS_RDONLY) ||
2997             !test_opt(sb, INIT_INODE_TABLE))
2998                 goto out;
2999
3000         elr = ext4_li_request_new(sb, first_not_zeroed);
3001         if (!elr) {
3002                 ret = -ENOMEM;
3003                 goto out;
3004         }
3005
3006         if (NULL == ext4_li_info) {
3007                 ret = ext4_li_info_new();
3008                 if (ret)
3009                         goto out;
3010         }
3011
3012         mutex_lock(&ext4_li_info->li_list_mtx);
3013         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3014         mutex_unlock(&ext4_li_info->li_list_mtx);
3015
3016         sbi->s_li_request = elr;
3017         /*
3018          * set elr to NULL here since it has been inserted to
3019          * the request_list and the removal and free of it is
3020          * handled by ext4_clear_request_list from now on.
3021          */
3022         elr = NULL;
3023
3024         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3025                 ret = ext4_run_lazyinit_thread();
3026                 if (ret)
3027                         goto out;
3028         }
3029 out:
3030         mutex_unlock(&ext4_li_mtx);
3031         if (ret)
3032                 kfree(elr);
3033         return ret;
3034 }
3035
3036 /*
3037  * We do not need to lock anything since this is called on
3038  * module unload.
3039  */
3040 static void ext4_destroy_lazyinit_thread(void)
3041 {
3042         /*
3043          * If thread exited earlier
3044          * there's nothing to be done.
3045          */
3046         if (!ext4_li_info || !ext4_lazyinit_task)
3047                 return;
3048
3049         kthread_stop(ext4_lazyinit_task);
3050 }
3051
3052 static int set_journal_csum_feature_set(struct super_block *sb)
3053 {
3054         int ret = 1;
3055         int compat, incompat;
3056         struct ext4_sb_info *sbi = EXT4_SB(sb);
3057
3058         if (ext4_has_metadata_csum(sb)) {
3059                 /* journal checksum v3 */
3060                 compat = 0;
3061                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3062         } else {
3063                 /* journal checksum v1 */
3064                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3065                 incompat = 0;
3066         }
3067
3068         jbd2_journal_clear_features(sbi->s_journal,
3069                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3070                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3071                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3072         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3073                 ret = jbd2_journal_set_features(sbi->s_journal,
3074                                 compat, 0,
3075                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3076                                 incompat);
3077         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3078                 ret = jbd2_journal_set_features(sbi->s_journal,
3079                                 compat, 0,
3080                                 incompat);
3081                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3082                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3083         } else {
3084                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3085                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3086         }
3087
3088         return ret;
3089 }
3090
3091 /*
3092  * Note: calculating the overhead so we can be compatible with
3093  * historical BSD practice is quite difficult in the face of
3094  * clusters/bigalloc.  This is because multiple metadata blocks from
3095  * different block group can end up in the same allocation cluster.
3096  * Calculating the exact overhead in the face of clustered allocation
3097  * requires either O(all block bitmaps) in memory or O(number of block
3098  * groups**2) in time.  We will still calculate the superblock for
3099  * older file systems --- and if we come across with a bigalloc file
3100  * system with zero in s_overhead_clusters the estimate will be close to
3101  * correct especially for very large cluster sizes --- but for newer
3102  * file systems, it's better to calculate this figure once at mkfs
3103  * time, and store it in the superblock.  If the superblock value is
3104  * present (even for non-bigalloc file systems), we will use it.
3105  */
3106 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3107                           char *buf)
3108 {
3109         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3110         struct ext4_group_desc  *gdp;
3111         ext4_fsblk_t            first_block, last_block, b;
3112         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3113         int                     s, j, count = 0;
3114
3115         if (!ext4_has_feature_bigalloc(sb))
3116                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3117                         sbi->s_itb_per_group + 2);
3118
3119         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3120                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3121         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3122         for (i = 0; i < ngroups; i++) {
3123                 gdp = ext4_get_group_desc(sb, i, NULL);
3124                 b = ext4_block_bitmap(sb, gdp);
3125                 if (b >= first_block && b <= last_block) {
3126                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3127                         count++;
3128                 }
3129                 b = ext4_inode_bitmap(sb, gdp);
3130                 if (b >= first_block && b <= last_block) {
3131                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3132                         count++;
3133                 }
3134                 b = ext4_inode_table(sb, gdp);
3135                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3136                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3137                                 int c = EXT4_B2C(sbi, b - first_block);
3138                                 ext4_set_bit(c, buf);
3139                                 count++;
3140                         }
3141                 if (i != grp)
3142                         continue;
3143                 s = 0;
3144                 if (ext4_bg_has_super(sb, grp)) {
3145                         ext4_set_bit(s++, buf);
3146                         count++;
3147                 }
3148                 for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3149                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3150                         count++;
3151                 }
3152         }
3153         if (!count)
3154                 return 0;
3155         return EXT4_CLUSTERS_PER_GROUP(sb) -
3156                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3157 }
3158
3159 /*
3160  * Compute the overhead and stash it in sbi->s_overhead
3161  */
3162 int ext4_calculate_overhead(struct super_block *sb)
3163 {
3164         struct ext4_sb_info *sbi = EXT4_SB(sb);
3165         struct ext4_super_block *es = sbi->s_es;
3166         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3167         ext4_fsblk_t overhead = 0;
3168         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3169
3170         if (!buf)
3171                 return -ENOMEM;
3172
3173         /*
3174          * Compute the overhead (FS structures).  This is constant
3175          * for a given filesystem unless the number of block groups
3176          * changes so we cache the previous value until it does.
3177          */
3178
3179         /*
3180          * All of the blocks before first_data_block are overhead
3181          */
3182         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3183
3184         /*
3185          * Add the overhead found in each block group
3186          */
3187         for (i = 0; i < ngroups; i++) {
3188                 int blks;
3189
3190                 blks = count_overhead(sb, i, buf);
3191                 overhead += blks;
3192                 if (blks)
3193                         memset(buf, 0, PAGE_SIZE);
3194                 cond_resched();
3195         }
3196         /* Add the internal journal blocks as well */
3197         if (sbi->s_journal && !sbi->journal_bdev)
3198                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3199
3200         sbi->s_overhead = overhead;
3201         smp_wmb();
3202         free_page((unsigned long) buf);
3203         return 0;
3204 }
3205
3206 static void ext4_set_resv_clusters(struct super_block *sb)
3207 {
3208         ext4_fsblk_t resv_clusters;
3209         struct ext4_sb_info *sbi = EXT4_SB(sb);
3210
3211         /*
3212          * There's no need to reserve anything when we aren't using extents.
3213          * The space estimates are exact, there are no unwritten extents,
3214          * hole punching doesn't need new metadata... This is needed especially
3215          * to keep ext2/3 backward compatibility.
3216          */
3217         if (!ext4_has_feature_extents(sb))
3218                 return;
3219         /*
3220          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3221          * This should cover the situations where we can not afford to run
3222          * out of space like for example punch hole, or converting
3223          * unwritten extents in delalloc path. In most cases such
3224          * allocation would require 1, or 2 blocks, higher numbers are
3225          * very rare.
3226          */
3227         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3228                          sbi->s_cluster_bits);
3229
3230         do_div(resv_clusters, 50);
3231         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3232
3233         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3234 }
3235
3236 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3237 {
3238         char *orig_data = kstrdup(data, GFP_KERNEL);
3239         struct buffer_head *bh;
3240         struct ext4_super_block *es = NULL;
3241         struct ext4_sb_info *sbi;
3242         ext4_fsblk_t block;
3243         ext4_fsblk_t sb_block = get_sb_block(&data);
3244         ext4_fsblk_t logical_sb_block;
3245         unsigned long offset = 0;
3246         unsigned long journal_devnum = 0;
3247         unsigned long def_mount_opts;
3248         struct inode *root;
3249         const char *descr;
3250         int ret = -ENOMEM;
3251         int blocksize, clustersize;
3252         unsigned int db_count;
3253         unsigned int i;
3254         int needs_recovery, has_huge_files, has_bigalloc;
3255         __u64 blocks_count;
3256         int err = 0;
3257         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3258         ext4_group_t first_not_zeroed;
3259
3260         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3261         if (!sbi)
3262                 goto out_free_orig;
3263
3264         sbi->s_blockgroup_lock =
3265                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3266         if (!sbi->s_blockgroup_lock) {
3267                 kfree(sbi);
3268                 goto out_free_orig;
3269         }
3270         sb->s_fs_info = sbi;
3271         sbi->s_sb = sb;
3272         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3273         sbi->s_sb_block = sb_block;
3274         if (sb->s_bdev->bd_part)
3275                 sbi->s_sectors_written_start =
3276                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3277
3278         /* Cleanup superblock name */
3279         strreplace(sb->s_id, '/', '!');
3280
3281         /* -EINVAL is default */
3282         ret = -EINVAL;
3283         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3284         if (!blocksize) {
3285                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3286                 goto out_fail;
3287         }
3288
3289         /*
3290          * The ext4 superblock will not be buffer aligned for other than 1kB
3291          * block sizes.  We need to calculate the offset from buffer start.
3292          */
3293         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3294                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3295                 offset = do_div(logical_sb_block, blocksize);
3296         } else {
3297                 logical_sb_block = sb_block;
3298         }
3299
3300         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3301                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3302                 goto out_fail;
3303         }
3304         /*
3305          * Note: s_es must be initialized as soon as possible because
3306          *       some ext4 macro-instructions depend on its value
3307          */
3308         es = (struct ext4_super_block *) (bh->b_data + offset);
3309         sbi->s_es = es;
3310         sb->s_magic = le16_to_cpu(es->s_magic);
3311         if (sb->s_magic != EXT4_SUPER_MAGIC)
3312                 goto cantfind_ext4;
3313         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3314
3315         /* Warn if metadata_csum and gdt_csum are both set. */
3316         if (ext4_has_feature_metadata_csum(sb) &&
3317             ext4_has_feature_gdt_csum(sb))
3318                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3319                              "redundant flags; please run fsck.");
3320
3321         /* Check for a known checksum algorithm */
3322         if (!ext4_verify_csum_type(sb, es)) {
3323                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3324                          "unknown checksum algorithm.");
3325                 silent = 1;
3326                 goto cantfind_ext4;
3327         }
3328
3329         /* Load the checksum driver */
3330         if (ext4_has_feature_metadata_csum(sb)) {
3331                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3332                 if (IS_ERR(sbi->s_chksum_driver)) {
3333                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3334                         ret = PTR_ERR(sbi->s_chksum_driver);
3335                         sbi->s_chksum_driver = NULL;
3336                         goto failed_mount;
3337                 }
3338         }
3339
3340         /* Check superblock checksum */
3341         if (!ext4_superblock_csum_verify(sb, es)) {
3342                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3343                          "invalid superblock checksum.  Run e2fsck?");
3344                 silent = 1;
3345                 ret = -EFSBADCRC;
3346                 goto cantfind_ext4;
3347         }
3348
3349         /* Precompute checksum seed for all metadata */
3350         if (ext4_has_feature_csum_seed(sb))
3351                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3352         else if (ext4_has_metadata_csum(sb))
3353                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3354                                                sizeof(es->s_uuid));
3355
3356         /* Set defaults before we parse the mount options */
3357         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3358         set_opt(sb, INIT_INODE_TABLE);
3359         if (def_mount_opts & EXT4_DEFM_DEBUG)
3360                 set_opt(sb, DEBUG);
3361         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3362                 set_opt(sb, GRPID);
3363         if (def_mount_opts & EXT4_DEFM_UID16)
3364                 set_opt(sb, NO_UID32);
3365         /* xattr user namespace & acls are now defaulted on */
3366         set_opt(sb, XATTR_USER);
3367 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3368         set_opt(sb, POSIX_ACL);
3369 #endif
3370         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3371         if (ext4_has_metadata_csum(sb))
3372                 set_opt(sb, JOURNAL_CHECKSUM);
3373
3374         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3375                 set_opt(sb, JOURNAL_DATA);
3376         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3377                 set_opt(sb, ORDERED_DATA);
3378         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3379                 set_opt(sb, WRITEBACK_DATA);
3380
3381         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3382                 set_opt(sb, ERRORS_PANIC);
3383         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3384                 set_opt(sb, ERRORS_CONT);
3385         else
3386                 set_opt(sb, ERRORS_RO);
3387         /* block_validity enabled by default; disable with noblock_validity */
3388         set_opt(sb, BLOCK_VALIDITY);
3389         if (def_mount_opts & EXT4_DEFM_DISCARD)
3390                 set_opt(sb, DISCARD);
3391
3392         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3393         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3394         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3395         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3396         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3397
3398         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3399                 set_opt(sb, BARRIER);
3400
3401         /*
3402          * enable delayed allocation by default
3403          * Use -o nodelalloc to turn it off
3404          */
3405         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3406             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3407                 set_opt(sb, DELALLOC);
3408
3409         /*
3410          * set default s_li_wait_mult for lazyinit, for the case there is
3411          * no mount option specified.
3412          */
3413         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3414
3415         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3416                            &journal_devnum, &journal_ioprio, 0)) {
3417                 ext4_msg(sb, KERN_WARNING,
3418                          "failed to parse options in superblock: %s",
3419                          sbi->s_es->s_mount_opts);
3420         }
3421         sbi->s_def_mount_opt = sbi->s_mount_opt;
3422         if (!parse_options((char *) data, sb, &journal_devnum,
3423                            &journal_ioprio, 0))
3424                 goto failed_mount;
3425
3426         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3427                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3428                             "with data=journal disables delayed "
3429                             "allocation and O_DIRECT support!\n");
3430                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3431                         ext4_msg(sb, KERN_ERR, "can't mount with "
3432                                  "both data=journal and delalloc");
3433                         goto failed_mount;
3434                 }
3435                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3436                         ext4_msg(sb, KERN_ERR, "can't mount with "
3437                                  "both data=journal and dioread_nolock");
3438                         goto failed_mount;
3439                 }
3440                 if (test_opt(sb, DAX)) {
3441                         ext4_msg(sb, KERN_ERR, "can't mount with "
3442                                  "both data=journal and dax");
3443                         goto failed_mount;
3444                 }
3445                 if (test_opt(sb, DELALLOC))
3446                         clear_opt(sb, DELALLOC);
3447         } else {
3448                 sb->s_iflags |= SB_I_CGROUPWB;
3449         }
3450
3451         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3452                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3453
3454         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3455             (ext4_has_compat_features(sb) ||
3456              ext4_has_ro_compat_features(sb) ||
3457              ext4_has_incompat_features(sb)))
3458                 ext4_msg(sb, KERN_WARNING,
3459                        "feature flags set on rev 0 fs, "
3460                        "running e2fsck is recommended");
3461
3462         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3463                 set_opt2(sb, HURD_COMPAT);
3464                 if (ext4_has_feature_64bit(sb)) {
3465                         ext4_msg(sb, KERN_ERR,
3466                                  "The Hurd can't support 64-bit file systems");
3467                         goto failed_mount;
3468                 }
3469         }
3470
3471         if (IS_EXT2_SB(sb)) {
3472                 if (ext2_feature_set_ok(sb))
3473                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3474                                  "using the ext4 subsystem");
3475                 else {
3476                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3477                                  "to feature incompatibilities");
3478                         goto failed_mount;
3479                 }
3480         }
3481
3482         if (IS_EXT3_SB(sb)) {
3483                 if (ext3_feature_set_ok(sb))
3484                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3485                                  "using the ext4 subsystem");
3486                 else {
3487                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3488                                  "to feature incompatibilities");
3489                         goto failed_mount;
3490                 }
3491         }
3492
3493         /*
3494          * Check feature flags regardless of the revision level, since we
3495          * previously didn't change the revision level when setting the flags,
3496          * so there is a chance incompat flags are set on a rev 0 filesystem.
3497          */
3498         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3499                 goto failed_mount;
3500
3501         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3502         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3503             blocksize > EXT4_MAX_BLOCK_SIZE) {
3504                 ext4_msg(sb, KERN_ERR,
3505                        "Unsupported filesystem blocksize %d", blocksize);
3506                 goto failed_mount;
3507         }
3508
3509         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3510                 ext4_msg(sb, KERN_ERR,
3511                          "Number of reserved GDT blocks insanely large: %d",
3512                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3513                 goto failed_mount;
3514         }
3515
3516         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3517                 err = bdev_dax_supported(sb, blocksize);
3518                 if (err)
3519                         goto failed_mount;
3520         }
3521
3522         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3523                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3524                          es->s_encryption_level);
3525                 goto failed_mount;
3526         }
3527
3528         if (sb->s_blocksize != blocksize) {
3529                 /* Validate the filesystem blocksize */
3530                 if (!sb_set_blocksize(sb, blocksize)) {
3531                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3532                                         blocksize);
3533                         goto failed_mount;
3534                 }
3535
3536                 brelse(bh);
3537                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3538                 offset = do_div(logical_sb_block, blocksize);
3539                 bh = sb_bread_unmovable(sb, logical_sb_block);
3540                 if (!bh) {
3541                         ext4_msg(sb, KERN_ERR,
3542                                "Can't read superblock on 2nd try");
3543                         goto failed_mount;
3544                 }
3545                 es = (struct ext4_super_block *)(bh->b_data + offset);
3546                 sbi->s_es = es;
3547                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3548                         ext4_msg(sb, KERN_ERR,
3549                                "Magic mismatch, very weird!");
3550                         goto failed_mount;
3551                 }
3552         }
3553
3554         has_huge_files = ext4_has_feature_huge_file(sb);
3555         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3556                                                       has_huge_files);
3557         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3558
3559         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3560                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3561                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3562         } else {
3563                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3564                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3565                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3566                     (!is_power_of_2(sbi->s_inode_size)) ||
3567                     (sbi->s_inode_size > blocksize)) {
3568                         ext4_msg(sb, KERN_ERR,
3569                                "unsupported inode size: %d",
3570                                sbi->s_inode_size);
3571                         goto failed_mount;
3572                 }
3573                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3574                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3575         }
3576
3577         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3578         if (ext4_has_feature_64bit(sb)) {
3579                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3580                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3581                     !is_power_of_2(sbi->s_desc_size)) {
3582                         ext4_msg(sb, KERN_ERR,
3583                                "unsupported descriptor size %lu",
3584                                sbi->s_desc_size);
3585                         goto failed_mount;
3586                 }
3587         } else
3588                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3589
3590         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3591         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3592         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3593                 goto cantfind_ext4;
3594
3595         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3596         if (sbi->s_inodes_per_block == 0)
3597                 goto cantfind_ext4;
3598         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3599                                         sbi->s_inodes_per_block;
3600         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3601         sbi->s_sbh = bh;
3602         sbi->s_mount_state = le16_to_cpu(es->s_state);
3603         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3604         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3605
3606         for (i = 0; i < 4; i++)
3607                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3608         sbi->s_def_hash_version = es->s_def_hash_version;
3609         if (ext4_has_feature_dir_index(sb)) {
3610                 i = le32_to_cpu(es->s_flags);
3611                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3612                         sbi->s_hash_unsigned = 3;
3613                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3614 #ifdef __CHAR_UNSIGNED__
3615                         if (!(sb->s_flags & MS_RDONLY))
3616                                 es->s_flags |=
3617                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3618                         sbi->s_hash_unsigned = 3;
3619 #else
3620                         if (!(sb->s_flags & MS_RDONLY))
3621                                 es->s_flags |=
3622                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3623 #endif
3624                 }
3625         }
3626
3627         /* Handle clustersize */
3628         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3629         has_bigalloc = ext4_has_feature_bigalloc(sb);
3630         if (has_bigalloc) {
3631                 if (clustersize < blocksize) {
3632                         ext4_msg(sb, KERN_ERR,
3633                                  "cluster size (%d) smaller than "
3634                                  "block size (%d)", clustersize, blocksize);
3635                         goto failed_mount;
3636                 }
3637                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3638                         le32_to_cpu(es->s_log_block_size);
3639                 sbi->s_clusters_per_group =
3640                         le32_to_cpu(es->s_clusters_per_group);
3641                 if (sbi->s_clusters_per_group > blocksize * 8) {
3642                         ext4_msg(sb, KERN_ERR,
3643                                  "#clusters per group too big: %lu",
3644                                  sbi->s_clusters_per_group);
3645                         goto failed_mount;
3646                 }
3647                 if (sbi->s_blocks_per_group !=
3648                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3649                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3650                                  "clusters per group (%lu) inconsistent",
3651                                  sbi->s_blocks_per_group,
3652                                  sbi->s_clusters_per_group);
3653                         goto failed_mount;
3654                 }
3655         } else {
3656                 if (clustersize != blocksize) {
3657                         ext4_warning(sb, "fragment/cluster size (%d) != "
3658                                      "block size (%d)", clustersize,
3659                                      blocksize);
3660                         clustersize = blocksize;
3661                 }
3662                 if (sbi->s_blocks_per_group > blocksize * 8) {
3663                         ext4_msg(sb, KERN_ERR,
3664                                  "#blocks per group too big: %lu",
3665                                  sbi->s_blocks_per_group);
3666                         goto failed_mount;
3667                 }
3668                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3669                 sbi->s_cluster_bits = 0;
3670         }
3671         sbi->s_cluster_ratio = clustersize / blocksize;
3672
3673         if (sbi->s_inodes_per_group > blocksize * 8) {
3674                 ext4_msg(sb, KERN_ERR,
3675                        "#inodes per group too big: %lu",
3676                        sbi->s_inodes_per_group);
3677                 goto failed_mount;
3678         }
3679
3680         /* Do we have standard group size of clustersize * 8 blocks ? */
3681         if (sbi->s_blocks_per_group == clustersize << 3)
3682                 set_opt2(sb, STD_GROUP_SIZE);
3683
3684         /*
3685          * Test whether we have more sectors than will fit in sector_t,
3686          * and whether the max offset is addressable by the page cache.
3687          */
3688         err = generic_check_addressable(sb->s_blocksize_bits,
3689                                         ext4_blocks_count(es));
3690         if (err) {
3691                 ext4_msg(sb, KERN_ERR, "filesystem"
3692                          " too large to mount safely on this system");
3693                 if (sizeof(sector_t) < 8)
3694                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3695                 goto failed_mount;
3696         }
3697
3698         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3699                 goto cantfind_ext4;
3700
3701         /* check blocks count against device size */
3702         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3703         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3704                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3705                        "exceeds size of device (%llu blocks)",
3706                        ext4_blocks_count(es), blocks_count);
3707                 goto failed_mount;
3708         }
3709
3710         /*
3711          * It makes no sense for the first data block to be beyond the end
3712          * of the filesystem.
3713          */
3714         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3715                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3716                          "block %u is beyond end of filesystem (%llu)",
3717                          le32_to_cpu(es->s_first_data_block),
3718                          ext4_blocks_count(es));
3719                 goto failed_mount;
3720         }
3721         blocks_count = (ext4_blocks_count(es) -
3722                         le32_to_cpu(es->s_first_data_block) +
3723                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3724         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3725         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3726                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3727                        "(block count %llu, first data block %u, "
3728                        "blocks per group %lu)", sbi->s_groups_count,
3729                        ext4_blocks_count(es),
3730                        le32_to_cpu(es->s_first_data_block),
3731                        EXT4_BLOCKS_PER_GROUP(sb));
3732                 goto failed_mount;
3733         }
3734         sbi->s_groups_count = blocks_count;
3735         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3736                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3737         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3738                    EXT4_DESC_PER_BLOCK(sb);
3739         sbi->s_group_desc = ext4_kvmalloc(db_count *
3740                                           sizeof(struct buffer_head *),
3741                                           GFP_KERNEL);
3742         if (sbi->s_group_desc == NULL) {
3743                 ext4_msg(sb, KERN_ERR, "not enough memory");
3744                 ret = -ENOMEM;
3745                 goto failed_mount;
3746         }
3747
3748         bgl_lock_init(sbi->s_blockgroup_lock);
3749
3750         for (i = 0; i < db_count; i++) {
3751                 block = descriptor_loc(sb, logical_sb_block, i);
3752                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3753                 if (!sbi->s_group_desc[i]) {
3754                         ext4_msg(sb, KERN_ERR,
3755                                "can't read group descriptor %d", i);
3756                         db_count = i;
3757                         goto failed_mount2;
3758                 }
3759         }
3760         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3761                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3762                 ret = -EFSCORRUPTED;
3763                 goto failed_mount2;
3764         }
3765
3766         sbi->s_gdb_count = db_count;
3767         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3768         spin_lock_init(&sbi->s_next_gen_lock);
3769
3770         setup_timer(&sbi->s_err_report, print_daily_error_info,
3771                 (unsigned long) sb);
3772
3773         /* Register extent status tree shrinker */
3774         if (ext4_es_register_shrinker(sbi))
3775                 goto failed_mount3;
3776
3777         sbi->s_stripe = ext4_get_stripe_size(sbi);
3778         sbi->s_extent_max_zeroout_kb = 32;
3779
3780         /*
3781          * set up enough so that it can read an inode
3782          */
3783         sb->s_op = &ext4_sops;
3784         sb->s_export_op = &ext4_export_ops;
3785         sb->s_xattr = ext4_xattr_handlers;
3786         sb->s_cop = &ext4_cryptops;
3787 #ifdef CONFIG_QUOTA
3788         sb->dq_op = &ext4_quota_operations;
3789         if (ext4_has_feature_quota(sb))
3790                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3791         else
3792                 sb->s_qcop = &ext4_qctl_operations;
3793         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3794 #endif
3795         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3796
3797         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3798         mutex_init(&sbi->s_orphan_lock);
3799
3800         sb->s_root = NULL;
3801
3802         needs_recovery = (es->s_last_orphan != 0 ||
3803                           ext4_has_feature_journal_needs_recovery(sb));
3804
3805         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3806                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3807                         goto failed_mount3a;
3808
3809         /*
3810          * The first inode we look at is the journal inode.  Don't try
3811          * root first: it may be modified in the journal!
3812          */
3813         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3814                 if (ext4_load_journal(sb, es, journal_devnum))
3815                         goto failed_mount3a;
3816         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3817                    ext4_has_feature_journal_needs_recovery(sb)) {
3818                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3819                        "suppressed and not mounted read-only");
3820                 goto failed_mount_wq;
3821         } else {
3822                 /* Nojournal mode, all journal mount options are illegal */
3823                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3824                         ext4_msg(sb, KERN_ERR, "can't mount with "
3825                                  "journal_checksum, fs mounted w/o journal");
3826                         goto failed_mount_wq;
3827                 }
3828                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3829                         ext4_msg(sb, KERN_ERR, "can't mount with "
3830                                  "journal_async_commit, fs mounted w/o journal");
3831                         goto failed_mount_wq;
3832                 }
3833                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3834                         ext4_msg(sb, KERN_ERR, "can't mount with "
3835                                  "commit=%lu, fs mounted w/o journal",
3836                                  sbi->s_commit_interval / HZ);
3837                         goto failed_mount_wq;
3838                 }
3839                 if (EXT4_MOUNT_DATA_FLAGS &
3840                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3841                         ext4_msg(sb, KERN_ERR, "can't mount with "
3842                                  "data=, fs mounted w/o journal");
3843                         goto failed_mount_wq;
3844                 }
3845                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3846                 clear_opt(sb, JOURNAL_CHECKSUM);
3847                 clear_opt(sb, DATA_FLAGS);
3848                 sbi->s_journal = NULL;
3849                 needs_recovery = 0;
3850                 goto no_journal;
3851         }
3852
3853         if (ext4_has_feature_64bit(sb) &&
3854             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3855                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3856                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3857                 goto failed_mount_wq;
3858         }
3859
3860         if (!set_journal_csum_feature_set(sb)) {
3861                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3862                          "feature set");
3863                 goto failed_mount_wq;
3864         }
3865
3866         /* We have now updated the journal if required, so we can
3867          * validate the data journaling mode. */
3868         switch (test_opt(sb, DATA_FLAGS)) {
3869         case 0:
3870                 /* No mode set, assume a default based on the journal
3871                  * capabilities: ORDERED_DATA if the journal can
3872                  * cope, else JOURNAL_DATA
3873                  */
3874                 if (jbd2_journal_check_available_features
3875                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3876                         set_opt(sb, ORDERED_DATA);
3877                 else
3878                         set_opt(sb, JOURNAL_DATA);
3879                 break;
3880
3881         case EXT4_MOUNT_ORDERED_DATA:
3882         case EXT4_MOUNT_WRITEBACK_DATA:
3883                 if (!jbd2_journal_check_available_features
3884                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3885                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3886                                "requested data journaling mode");
3887                         goto failed_mount_wq;
3888                 }
3889         default:
3890                 break;
3891         }
3892         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3893
3894         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3895
3896 no_journal:
3897         sbi->s_mb_cache = ext4_xattr_create_cache();
3898         if (!sbi->s_mb_cache) {
3899                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3900                 goto failed_mount_wq;
3901         }
3902
3903         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3904             (blocksize != PAGE_SIZE)) {
3905                 ext4_msg(sb, KERN_ERR,
3906                          "Unsupported blocksize for fs encryption");
3907                 goto failed_mount_wq;
3908         }
3909
3910         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3911             !ext4_has_feature_encrypt(sb)) {
3912                 ext4_set_feature_encrypt(sb);
3913                 ext4_commit_super(sb, 1);
3914         }
3915
3916         /*
3917          * Get the # of file system overhead blocks from the
3918          * superblock if present.
3919          */
3920         if (es->s_overhead_clusters)
3921                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3922         else {
3923                 err = ext4_calculate_overhead(sb);
3924                 if (err)
3925                         goto failed_mount_wq;
3926         }
3927
3928         /*
3929          * The maximum number of concurrent works can be high and
3930          * concurrency isn't really necessary.  Limit it to 1.
3931          */
3932         EXT4_SB(sb)->rsv_conversion_wq =
3933                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3934         if (!EXT4_SB(sb)->rsv_conversion_wq) {
3935                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3936                 ret = -ENOMEM;
3937                 goto failed_mount4;
3938         }
3939
3940         /*
3941          * The jbd2_journal_load will have done any necessary log recovery,
3942          * so we can safely mount the rest of the filesystem now.
3943          */
3944
3945         root = ext4_iget(sb, EXT4_ROOT_INO);
3946         if (IS_ERR(root)) {
3947                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3948                 ret = PTR_ERR(root);
3949                 root = NULL;
3950                 goto failed_mount4;
3951         }
3952         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3953                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3954                 iput(root);
3955                 goto failed_mount4;
3956         }
3957         sb->s_root = d_make_root(root);
3958         if (!sb->s_root) {
3959                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3960                 ret = -ENOMEM;
3961                 goto failed_mount4;
3962         }
3963
3964         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3965                 sb->s_flags |= MS_RDONLY;
3966
3967         /* determine the minimum size of new large inodes, if present */
3968         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3969                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3970                                                      EXT4_GOOD_OLD_INODE_SIZE;
3971                 if (ext4_has_feature_extra_isize(sb)) {
3972                         if (sbi->s_want_extra_isize <
3973                             le16_to_cpu(es->s_want_extra_isize))
3974                                 sbi->s_want_extra_isize =
3975                                         le16_to_cpu(es->s_want_extra_isize);
3976                         if (sbi->s_want_extra_isize <
3977                             le16_to_cpu(es->s_min_extra_isize))
3978                                 sbi->s_want_extra_isize =
3979                                         le16_to_cpu(es->s_min_extra_isize);
3980                 }
3981         }
3982         /* Check if enough inode space is available */
3983         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3984                                                         sbi->s_inode_size) {
3985                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3986                                                        EXT4_GOOD_OLD_INODE_SIZE;
3987                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3988                          "available");
3989         }
3990
3991         ext4_set_resv_clusters(sb);
3992
3993         err = ext4_setup_system_zone(sb);
3994         if (err) {
3995                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3996                          "zone (%d)", err);
3997                 goto failed_mount4a;
3998         }
3999
4000         ext4_ext_init(sb);
4001         err = ext4_mb_init(sb);
4002         if (err) {
4003                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4004                          err);
4005                 goto failed_mount5;
4006         }
4007
4008         block = ext4_count_free_clusters(sb);
4009         ext4_free_blocks_count_set(sbi->s_es,
4010                                    EXT4_C2B(sbi, block));
4011         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4012                                   GFP_KERNEL);
4013         if (!err) {
4014                 unsigned long freei = ext4_count_free_inodes(sb);
4015                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4016                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4017                                           GFP_KERNEL);
4018         }
4019         if (!err)
4020                 err = percpu_counter_init(&sbi->s_dirs_counter,
4021                                           ext4_count_dirs(sb), GFP_KERNEL);
4022         if (!err)
4023                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4024                                           GFP_KERNEL);
4025         if (!err)
4026                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4027
4028         if (err) {
4029                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4030                 goto failed_mount6;
4031         }
4032
4033         if (ext4_has_feature_flex_bg(sb))
4034                 if (!ext4_fill_flex_info(sb)) {
4035                         ext4_msg(sb, KERN_ERR,
4036                                "unable to initialize "
4037                                "flex_bg meta info!");
4038                         goto failed_mount6;
4039                 }
4040
4041         err = ext4_register_li_request(sb, first_not_zeroed);
4042         if (err)
4043                 goto failed_mount6;
4044
4045         err = ext4_register_sysfs(sb);
4046         if (err)
4047                 goto failed_mount7;
4048
4049 #ifdef CONFIG_QUOTA
4050         /* Enable quota usage during mount. */
4051         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4052                 err = ext4_enable_quotas(sb);
4053                 if (err)
4054                         goto failed_mount8;
4055         }
4056 #endif  /* CONFIG_QUOTA */
4057
4058         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4059         ext4_orphan_cleanup(sb, es);
4060         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4061         if (needs_recovery) {
4062                 ext4_msg(sb, KERN_INFO, "recovery complete");
4063                 ext4_mark_recovery_complete(sb, es);
4064         }
4065         if (EXT4_SB(sb)->s_journal) {
4066                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4067                         descr = " journalled data mode";
4068                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4069                         descr = " ordered data mode";
4070                 else
4071                         descr = " writeback data mode";
4072         } else
4073                 descr = "out journal";
4074
4075         if (test_opt(sb, DISCARD)) {
4076                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4077                 if (!blk_queue_discard(q))
4078                         ext4_msg(sb, KERN_WARNING,
4079                                  "mounting with \"discard\" option, but "
4080                                  "the device does not support discard");
4081         }
4082
4083         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4084                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4085                          "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4086                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4087
4088         if (es->s_error_count)
4089                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4090
4091         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4092         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4093         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4094         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4095
4096         kfree(orig_data);
4097 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4098         memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4099                                 EXT4_KEY_DESC_PREFIX_SIZE);
4100         sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4101 #endif
4102         return 0;
4103
4104 cantfind_ext4:
4105         if (!silent)
4106                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4107         goto failed_mount;
4108
4109 #ifdef CONFIG_QUOTA
4110 failed_mount8:
4111         ext4_unregister_sysfs(sb);
4112 #endif
4113 failed_mount7:
4114         ext4_unregister_li_request(sb);
4115 failed_mount6:
4116         ext4_mb_release(sb);
4117         if (sbi->s_flex_groups)
4118                 kvfree(sbi->s_flex_groups);
4119         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4120         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4121         percpu_counter_destroy(&sbi->s_dirs_counter);
4122         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4123 failed_mount5:
4124         ext4_ext_release(sb);
4125         ext4_release_system_zone(sb);
4126 failed_mount4a:
4127         dput(sb->s_root);
4128         sb->s_root = NULL;
4129 failed_mount4:
4130         ext4_msg(sb, KERN_ERR, "mount failed");
4131         if (EXT4_SB(sb)->rsv_conversion_wq)
4132                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4133 failed_mount_wq:
4134         if (sbi->s_mb_cache) {
4135                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4136                 sbi->s_mb_cache = NULL;
4137         }
4138         if (sbi->s_journal) {
4139                 jbd2_journal_destroy(sbi->s_journal);
4140                 sbi->s_journal = NULL;
4141         }
4142 failed_mount3a:
4143         ext4_es_unregister_shrinker(sbi);
4144 failed_mount3:
4145         del_timer_sync(&sbi->s_err_report);
4146         if (sbi->s_mmp_tsk)
4147                 kthread_stop(sbi->s_mmp_tsk);
4148 failed_mount2:
4149         for (i = 0; i < db_count; i++)
4150                 brelse(sbi->s_group_desc[i]);
4151         kvfree(sbi->s_group_desc);
4152 failed_mount:
4153         if (sbi->s_chksum_driver)
4154                 crypto_free_shash(sbi->s_chksum_driver);
4155 #ifdef CONFIG_QUOTA
4156         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4157                 kfree(sbi->s_qf_names[i]);
4158 #endif
4159         ext4_blkdev_remove(sbi);
4160         brelse(bh);
4161 out_fail:
4162         sb->s_fs_info = NULL;
4163         kfree(sbi->s_blockgroup_lock);
4164         kfree(sbi);
4165 out_free_orig:
4166         kfree(orig_data);
4167         return err ? err : ret;
4168 }
4169
4170 /*
4171  * Setup any per-fs journal parameters now.  We'll do this both on
4172  * initial mount, once the journal has been initialised but before we've
4173  * done any recovery; and again on any subsequent remount.
4174  */
4175 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4176 {
4177         struct ext4_sb_info *sbi = EXT4_SB(sb);
4178
4179         journal->j_commit_interval = sbi->s_commit_interval;
4180         journal->j_min_batch_time = sbi->s_min_batch_time;
4181         journal->j_max_batch_time = sbi->s_max_batch_time;
4182
4183         write_lock(&journal->j_state_lock);
4184         if (test_opt(sb, BARRIER))
4185                 journal->j_flags |= JBD2_BARRIER;
4186         else
4187                 journal->j_flags &= ~JBD2_BARRIER;
4188         if (test_opt(sb, DATA_ERR_ABORT))
4189                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4190         else
4191                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4192         write_unlock(&journal->j_state_lock);
4193 }
4194
4195 static journal_t *ext4_get_journal(struct super_block *sb,
4196                                    unsigned int journal_inum)
4197 {
4198         struct inode *journal_inode;
4199         journal_t *journal;
4200
4201         BUG_ON(!ext4_has_feature_journal(sb));
4202
4203         /* First, test for the existence of a valid inode on disk.  Bad
4204          * things happen if we iget() an unused inode, as the subsequent
4205          * iput() will try to delete it. */
4206
4207         journal_inode = ext4_iget(sb, journal_inum);
4208         if (IS_ERR(journal_inode)) {
4209                 ext4_msg(sb, KERN_ERR, "no journal found");
4210                 return NULL;
4211         }
4212         if (!journal_inode->i_nlink) {
4213                 make_bad_inode(journal_inode);
4214                 iput(journal_inode);
4215                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4216                 return NULL;
4217         }
4218
4219         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4220                   journal_inode, journal_inode->i_size);
4221         if (!S_ISREG(journal_inode->i_mode)) {
4222                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4223                 iput(journal_inode);
4224                 return NULL;
4225         }
4226
4227         journal = jbd2_journal_init_inode(journal_inode);
4228         if (!journal) {
4229                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4230                 iput(journal_inode);
4231                 return NULL;
4232         }
4233         journal->j_private = sb;
4234         ext4_init_journal_params(sb, journal);
4235         return journal;
4236 }
4237
4238 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4239                                        dev_t j_dev)
4240 {
4241         struct buffer_head *bh;
4242         journal_t *journal;
4243         ext4_fsblk_t start;
4244         ext4_fsblk_t len;
4245         int hblock, blocksize;
4246         ext4_fsblk_t sb_block;
4247         unsigned long offset;
4248         struct ext4_super_block *es;
4249         struct block_device *bdev;
4250
4251         BUG_ON(!ext4_has_feature_journal(sb));
4252
4253         bdev = ext4_blkdev_get(j_dev, sb);
4254         if (bdev == NULL)
4255                 return NULL;
4256
4257         blocksize = sb->s_blocksize;
4258         hblock = bdev_logical_block_size(bdev);
4259         if (blocksize < hblock) {
4260                 ext4_msg(sb, KERN_ERR,
4261                         "blocksize too small for journal device");
4262                 goto out_bdev;
4263         }
4264
4265         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4266         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4267         set_blocksize(bdev, blocksize);
4268         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4269                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4270                        "external journal");
4271                 goto out_bdev;
4272         }
4273
4274         es = (struct ext4_super_block *) (bh->b_data + offset);
4275         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4276             !(le32_to_cpu(es->s_feature_incompat) &
4277               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4278                 ext4_msg(sb, KERN_ERR, "external journal has "
4279                                         "bad superblock");
4280                 brelse(bh);
4281                 goto out_bdev;
4282         }
4283
4284         if ((le32_to_cpu(es->s_feature_ro_compat) &
4285              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4286             es->s_checksum != ext4_superblock_csum(sb, es)) {
4287                 ext4_msg(sb, KERN_ERR, "external journal has "
4288                                        "corrupt superblock");
4289                 brelse(bh);
4290                 goto out_bdev;
4291         }
4292
4293         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4294                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4295                 brelse(bh);
4296                 goto out_bdev;
4297         }
4298
4299         len = ext4_blocks_count(es);
4300         start = sb_block + 1;
4301         brelse(bh);     /* we're done with the superblock */
4302
4303         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4304                                         start, len, blocksize);
4305         if (!journal) {
4306                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4307                 goto out_bdev;
4308         }
4309         journal->j_private = sb;
4310         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4311         wait_on_buffer(journal->j_sb_buffer);
4312         if (!buffer_uptodate(journal->j_sb_buffer)) {
4313                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4314                 goto out_journal;
4315         }
4316         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4317                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4318                                         "user (unsupported) - %d",
4319                         be32_to_cpu(journal->j_superblock->s_nr_users));
4320                 goto out_journal;
4321         }
4322         EXT4_SB(sb)->journal_bdev = bdev;
4323         ext4_init_journal_params(sb, journal);
4324         return journal;
4325
4326 out_journal:
4327         jbd2_journal_destroy(journal);
4328 out_bdev:
4329         ext4_blkdev_put(bdev);
4330         return NULL;
4331 }
4332
4333 static int ext4_load_journal(struct super_block *sb,
4334                              struct ext4_super_block *es,
4335                              unsigned long journal_devnum)
4336 {
4337         journal_t *journal;
4338         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4339         dev_t journal_dev;
4340         int err = 0;
4341         int really_read_only;
4342
4343         BUG_ON(!ext4_has_feature_journal(sb));
4344
4345         if (journal_devnum &&
4346             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4347                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4348                         "numbers have changed");
4349                 journal_dev = new_decode_dev(journal_devnum);
4350         } else
4351                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4352
4353         really_read_only = bdev_read_only(sb->s_bdev);
4354
4355         /*
4356          * Are we loading a blank journal or performing recovery after a
4357          * crash?  For recovery, we need to check in advance whether we
4358          * can get read-write access to the device.
4359          */
4360         if (ext4_has_feature_journal_needs_recovery(sb)) {
4361                 if (sb->s_flags & MS_RDONLY) {
4362                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4363                                         "required on readonly filesystem");
4364                         if (really_read_only) {
4365                                 ext4_msg(sb, KERN_ERR, "write access "
4366                                         "unavailable, cannot proceed");
4367                                 return -EROFS;
4368                         }
4369                         ext4_msg(sb, KERN_INFO, "write access will "
4370                                "be enabled during recovery");
4371                 }
4372         }
4373
4374         if (journal_inum && journal_dev) {
4375                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4376                        "and inode journals!");
4377                 return -EINVAL;
4378         }
4379
4380         if (journal_inum) {
4381                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4382                         return -EINVAL;
4383         } else {
4384                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4385                         return -EINVAL;
4386         }
4387
4388         if (!(journal->j_flags & JBD2_BARRIER))
4389                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4390
4391         if (!ext4_has_feature_journal_needs_recovery(sb))
4392                 err = jbd2_journal_wipe(journal, !really_read_only);
4393         if (!err) {
4394                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4395                 if (save)
4396                         memcpy(save, ((char *) es) +
4397                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4398                 err = jbd2_journal_load(journal);
4399                 if (save)
4400                         memcpy(((char *) es) + EXT4_S_ERR_START,
4401                                save, EXT4_S_ERR_LEN);
4402                 kfree(save);
4403         }
4404
4405         if (err) {
4406                 ext4_msg(sb, KERN_ERR, "error loading journal");
4407                 jbd2_journal_destroy(journal);
4408                 return err;
4409         }
4410
4411         EXT4_SB(sb)->s_journal = journal;
4412         ext4_clear_journal_err(sb, es);
4413
4414         if (!really_read_only && journal_devnum &&
4415             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4416                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4417
4418                 /* Make sure we flush the recovery flag to disk. */
4419                 ext4_commit_super(sb, 1);
4420         }
4421
4422         return 0;
4423 }
4424
4425 static int ext4_commit_super(struct super_block *sb, int sync)
4426 {
4427         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4428         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4429         int error = 0;
4430
4431         if (!sbh || block_device_ejected(sb))
4432                 return error;
4433         /*
4434          * If the file system is mounted read-only, don't update the
4435          * superblock write time.  This avoids updating the superblock
4436          * write time when we are mounting the root file system
4437          * read/only but we need to replay the journal; at that point,
4438          * for people who are east of GMT and who make their clock
4439          * tick in localtime for Windows bug-for-bug compatibility,
4440          * the clock is set in the future, and this will cause e2fsck
4441          * to complain and force a full file system check.
4442          */
4443         if (!(sb->s_flags & MS_RDONLY))
4444                 es->s_wtime = cpu_to_le32(get_seconds());
4445         if (sb->s_bdev->bd_part)
4446                 es->s_kbytes_written =
4447                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4448                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4449                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4450         else
4451                 es->s_kbytes_written =
4452                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4453         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4454                 ext4_free_blocks_count_set(es,
4455                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4456                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4457         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4458                 es->s_free_inodes_count =
4459                         cpu_to_le32(percpu_counter_sum_positive(
4460                                 &EXT4_SB(sb)->s_freeinodes_counter));
4461         BUFFER_TRACE(sbh, "marking dirty");
4462         ext4_superblock_csum_set(sb);
4463         lock_buffer(sbh);
4464         if (buffer_write_io_error(sbh)) {
4465                 /*
4466                  * Oh, dear.  A previous attempt to write the
4467                  * superblock failed.  This could happen because the
4468                  * USB device was yanked out.  Or it could happen to
4469                  * be a transient write error and maybe the block will
4470                  * be remapped.  Nothing we can do but to retry the
4471                  * write and hope for the best.
4472                  */
4473                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4474                        "superblock detected");
4475                 clear_buffer_write_io_error(sbh);
4476                 set_buffer_uptodate(sbh);
4477         }
4478         mark_buffer_dirty(sbh);
4479         unlock_buffer(sbh);
4480         if (sync) {
4481                 error = __sync_dirty_buffer(sbh,
4482                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4483                 if (error)
4484                         return error;
4485
4486                 error = buffer_write_io_error(sbh);
4487                 if (error) {
4488                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4489                                "superblock");
4490                         clear_buffer_write_io_error(sbh);
4491                         set_buffer_uptodate(sbh);
4492                 }
4493         }
4494         return error;
4495 }
4496
4497 /*
4498  * Have we just finished recovery?  If so, and if we are mounting (or
4499  * remounting) the filesystem readonly, then we will end up with a
4500  * consistent fs on disk.  Record that fact.
4501  */
4502 static void ext4_mark_recovery_complete(struct super_block *sb,
4503                                         struct ext4_super_block *es)
4504 {
4505         journal_t *journal = EXT4_SB(sb)->s_journal;
4506
4507         if (!ext4_has_feature_journal(sb)) {
4508                 BUG_ON(journal != NULL);
4509                 return;
4510         }
4511         jbd2_journal_lock_updates(journal);
4512         if (jbd2_journal_flush(journal) < 0)
4513                 goto out;
4514
4515         if (ext4_has_feature_journal_needs_recovery(sb) &&
4516             sb->s_flags & MS_RDONLY) {
4517                 ext4_clear_feature_journal_needs_recovery(sb);
4518                 ext4_commit_super(sb, 1);
4519         }
4520
4521 out:
4522         jbd2_journal_unlock_updates(journal);
4523 }
4524
4525 /*
4526  * If we are mounting (or read-write remounting) a filesystem whose journal
4527  * has recorded an error from a previous lifetime, move that error to the
4528  * main filesystem now.
4529  */
4530 static void ext4_clear_journal_err(struct super_block *sb,
4531                                    struct ext4_super_block *es)
4532 {
4533         journal_t *journal;
4534         int j_errno;
4535         const char *errstr;
4536
4537         BUG_ON(!ext4_has_feature_journal(sb));
4538
4539         journal = EXT4_SB(sb)->s_journal;
4540
4541         /*
4542          * Now check for any error status which may have been recorded in the
4543          * journal by a prior ext4_error() or ext4_abort()
4544          */
4545
4546         j_errno = jbd2_journal_errno(journal);
4547         if (j_errno) {
4548                 char nbuf[16];
4549
4550                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4551                 ext4_warning(sb, "Filesystem error recorded "
4552                              "from previous mount: %s", errstr);
4553                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4554
4555                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4556                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4557                 ext4_commit_super(sb, 1);
4558
4559                 jbd2_journal_clear_err(journal);
4560                 jbd2_journal_update_sb_errno(journal);
4561         }
4562 }
4563
4564 /*
4565  * Force the running and committing transactions to commit,
4566  * and wait on the commit.
4567  */
4568 int ext4_force_commit(struct super_block *sb)
4569 {
4570         journal_t *journal;
4571
4572         if (sb->s_flags & MS_RDONLY)
4573                 return 0;
4574
4575         journal = EXT4_SB(sb)->s_journal;
4576         return ext4_journal_force_commit(journal);
4577 }
4578
4579 static int ext4_sync_fs(struct super_block *sb, int wait)
4580 {
4581         int ret = 0;
4582         tid_t target;
4583         bool needs_barrier = false;
4584         struct ext4_sb_info *sbi = EXT4_SB(sb);
4585
4586         trace_ext4_sync_fs(sb, wait);
4587         flush_workqueue(sbi->rsv_conversion_wq);
4588         /*
4589          * Writeback quota in non-journalled quota case - journalled quota has
4590          * no dirty dquots
4591          */
4592         dquot_writeback_dquots(sb, -1);
4593         /*
4594          * Data writeback is possible w/o journal transaction, so barrier must
4595          * being sent at the end of the function. But we can skip it if
4596          * transaction_commit will do it for us.
4597          */
4598         if (sbi->s_journal) {
4599                 target = jbd2_get_latest_transaction(sbi->s_journal);
4600                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4601                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4602                         needs_barrier = true;
4603
4604                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4605                         if (wait)
4606                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4607                                                            target);
4608                 }
4609         } else if (wait && test_opt(sb, BARRIER))
4610                 needs_barrier = true;
4611         if (needs_barrier) {
4612                 int err;
4613                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4614                 if (!ret)
4615                         ret = err;
4616         }
4617
4618         return ret;
4619 }
4620
4621 /*
4622  * LVM calls this function before a (read-only) snapshot is created.  This
4623  * gives us a chance to flush the journal completely and mark the fs clean.
4624  *
4625  * Note that only this function cannot bring a filesystem to be in a clean
4626  * state independently. It relies on upper layer to stop all data & metadata
4627  * modifications.
4628  */
4629 static int ext4_freeze(struct super_block *sb)
4630 {
4631         int error = 0;
4632         journal_t *journal;
4633
4634         if (sb->s_flags & MS_RDONLY)
4635                 return 0;
4636
4637         journal = EXT4_SB(sb)->s_journal;
4638
4639         if (journal) {
4640                 /* Now we set up the journal barrier. */
4641                 jbd2_journal_lock_updates(journal);
4642
4643                 /*
4644                  * Don't clear the needs_recovery flag if we failed to
4645                  * flush the journal.
4646                  */
4647                 error = jbd2_journal_flush(journal);
4648                 if (error < 0)
4649                         goto out;
4650
4651                 /* Journal blocked and flushed, clear needs_recovery flag. */
4652                 ext4_clear_feature_journal_needs_recovery(sb);
4653         }
4654
4655         error = ext4_commit_super(sb, 1);
4656 out:
4657         if (journal)
4658                 /* we rely on upper layer to stop further updates */
4659                 jbd2_journal_unlock_updates(journal);
4660         return error;
4661 }
4662
4663 /*
4664  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4665  * flag here, even though the filesystem is not technically dirty yet.
4666  */
4667 static int ext4_unfreeze(struct super_block *sb)
4668 {
4669         if (sb->s_flags & MS_RDONLY)
4670                 return 0;
4671
4672         if (EXT4_SB(sb)->s_journal) {
4673                 /* Reset the needs_recovery flag before the fs is unlocked. */
4674                 ext4_set_feature_journal_needs_recovery(sb);
4675         }
4676
4677         ext4_commit_super(sb, 1);
4678         return 0;
4679 }
4680
4681 /*
4682  * Structure to save mount options for ext4_remount's benefit
4683  */
4684 struct ext4_mount_options {
4685         unsigned long s_mount_opt;
4686         unsigned long s_mount_opt2;
4687         kuid_t s_resuid;
4688         kgid_t s_resgid;
4689         unsigned long s_commit_interval;
4690         u32 s_min_batch_time, s_max_batch_time;
4691 #ifdef CONFIG_QUOTA
4692         int s_jquota_fmt;
4693         char *s_qf_names[EXT4_MAXQUOTAS];
4694 #endif
4695 };
4696
4697 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4698 {
4699         struct ext4_super_block *es;
4700         struct ext4_sb_info *sbi = EXT4_SB(sb);
4701         unsigned long old_sb_flags;
4702         struct ext4_mount_options old_opts;
4703         int enable_quota = 0;
4704         ext4_group_t g;
4705         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4706         int err = 0;
4707 #ifdef CONFIG_QUOTA
4708         int i, j;
4709 #endif
4710         char *orig_data = kstrdup(data, GFP_KERNEL);
4711
4712         /* Store the original options */
4713         old_sb_flags = sb->s_flags;
4714         old_opts.s_mount_opt = sbi->s_mount_opt;
4715         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4716         old_opts.s_resuid = sbi->s_resuid;
4717         old_opts.s_resgid = sbi->s_resgid;
4718         old_opts.s_commit_interval = sbi->s_commit_interval;
4719         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4720         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4721 #ifdef CONFIG_QUOTA
4722         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4723         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4724                 if (sbi->s_qf_names[i]) {
4725                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4726                                                          GFP_KERNEL);
4727                         if (!old_opts.s_qf_names[i]) {
4728                                 for (j = 0; j < i; j++)
4729                                         kfree(old_opts.s_qf_names[j]);
4730                                 kfree(orig_data);
4731                                 return -ENOMEM;
4732                         }
4733                 } else
4734                         old_opts.s_qf_names[i] = NULL;
4735 #endif
4736         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4737                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4738
4739         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4740                 err = -EINVAL;
4741                 goto restore_opts;
4742         }
4743
4744         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4745             test_opt(sb, JOURNAL_CHECKSUM)) {
4746                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4747                          "during remount not supported; ignoring");
4748                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4749         }
4750
4751         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4752                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4753                         ext4_msg(sb, KERN_ERR, "can't mount with "
4754                                  "both data=journal and delalloc");
4755                         err = -EINVAL;
4756                         goto restore_opts;
4757                 }
4758                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4759                         ext4_msg(sb, KERN_ERR, "can't mount with "
4760                                  "both data=journal and dioread_nolock");
4761                         err = -EINVAL;
4762                         goto restore_opts;
4763                 }
4764                 if (test_opt(sb, DAX)) {
4765                         ext4_msg(sb, KERN_ERR, "can't mount with "
4766                                  "both data=journal and dax");
4767                         err = -EINVAL;
4768                         goto restore_opts;
4769                 }
4770         }
4771
4772         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4773                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4774                         "dax flag with busy inodes while remounting");
4775                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4776         }
4777
4778         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4779                 ext4_abort(sb, "Abort forced by user");
4780
4781         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4782                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4783
4784         es = sbi->s_es;
4785
4786         if (sbi->s_journal) {
4787                 ext4_init_journal_params(sb, sbi->s_journal);
4788                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4789         }
4790
4791         if (*flags & MS_LAZYTIME)
4792                 sb->s_flags |= MS_LAZYTIME;
4793
4794         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4795                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4796                         err = -EROFS;
4797                         goto restore_opts;
4798                 }
4799
4800                 if (*flags & MS_RDONLY) {
4801                         err = sync_filesystem(sb);
4802                         if (err < 0)
4803                                 goto restore_opts;
4804                         err = dquot_suspend(sb, -1);
4805                         if (err < 0)
4806                                 goto restore_opts;
4807
4808                         /*
4809                          * First of all, the unconditional stuff we have to do
4810                          * to disable replay of the journal when we next remount
4811                          */
4812                         sb->s_flags |= MS_RDONLY;
4813
4814                         /*
4815                          * OK, test if we are remounting a valid rw partition
4816                          * readonly, and if so set the rdonly flag and then
4817                          * mark the partition as valid again.
4818                          */
4819                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4820                             (sbi->s_mount_state & EXT4_VALID_FS))
4821                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4822
4823                         if (sbi->s_journal)
4824                                 ext4_mark_recovery_complete(sb, es);
4825                 } else {
4826                         /* Make sure we can mount this feature set readwrite */
4827                         if (ext4_has_feature_readonly(sb) ||
4828                             !ext4_feature_set_ok(sb, 0)) {
4829                                 err = -EROFS;
4830                                 goto restore_opts;
4831                         }
4832                         /*
4833                          * Make sure the group descriptor checksums
4834                          * are sane.  If they aren't, refuse to remount r/w.
4835                          */
4836                         for (g = 0; g < sbi->s_groups_count; g++) {
4837                                 struct ext4_group_desc *gdp =
4838                                         ext4_get_group_desc(sb, g, NULL);
4839
4840                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4841                                         ext4_msg(sb, KERN_ERR,
4842                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4843                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4844                                                le16_to_cpu(gdp->bg_checksum));
4845                                         err = -EFSBADCRC;
4846                                         goto restore_opts;
4847                                 }
4848                         }
4849
4850                         /*
4851                          * If we have an unprocessed orphan list hanging
4852                          * around from a previously readonly bdev mount,
4853                          * require a full umount/remount for now.
4854                          */
4855                         if (es->s_last_orphan) {
4856                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4857                                        "remount RDWR because of unprocessed "
4858                                        "orphan inode list.  Please "
4859                                        "umount/remount instead");
4860                                 err = -EINVAL;
4861                                 goto restore_opts;
4862                         }
4863
4864                         /*
4865                          * Mounting a RDONLY partition read-write, so reread
4866                          * and store the current valid flag.  (It may have
4867                          * been changed by e2fsck since we originally mounted
4868                          * the partition.)
4869                          */
4870                         if (sbi->s_journal)
4871                                 ext4_clear_journal_err(sb, es);
4872                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4873                         if (!ext4_setup_super(sb, es, 0))
4874                                 sb->s_flags &= ~MS_RDONLY;
4875                         if (ext4_has_feature_mmp(sb))
4876                                 if (ext4_multi_mount_protect(sb,
4877                                                 le64_to_cpu(es->s_mmp_block))) {
4878                                         err = -EROFS;
4879                                         goto restore_opts;
4880                                 }
4881                         enable_quota = 1;
4882                 }
4883         }
4884
4885         /*
4886          * Reinitialize lazy itable initialization thread based on
4887          * current settings
4888          */
4889         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4890                 ext4_unregister_li_request(sb);
4891         else {
4892                 ext4_group_t first_not_zeroed;
4893                 first_not_zeroed = ext4_has_uninit_itable(sb);
4894                 ext4_register_li_request(sb, first_not_zeroed);
4895         }
4896
4897         ext4_setup_system_zone(sb);
4898         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4899                 ext4_commit_super(sb, 1);
4900
4901 #ifdef CONFIG_QUOTA
4902         /* Release old quota file names */
4903         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4904                 kfree(old_opts.s_qf_names[i]);
4905         if (enable_quota) {
4906                 if (sb_any_quota_suspended(sb))
4907                         dquot_resume(sb, -1);
4908                 else if (ext4_has_feature_quota(sb)) {
4909                         err = ext4_enable_quotas(sb);
4910                         if (err)
4911                                 goto restore_opts;
4912                 }
4913         }
4914 #endif
4915
4916         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4917         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4918         kfree(orig_data);
4919         return 0;
4920
4921 restore_opts:
4922         sb->s_flags = old_sb_flags;
4923         sbi->s_mount_opt = old_opts.s_mount_opt;
4924         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4925         sbi->s_resuid = old_opts.s_resuid;
4926         sbi->s_resgid = old_opts.s_resgid;
4927         sbi->s_commit_interval = old_opts.s_commit_interval;
4928         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4929         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4930 #ifdef CONFIG_QUOTA
4931         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4932         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4933                 kfree(sbi->s_qf_names[i]);
4934                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4935         }
4936 #endif
4937         kfree(orig_data);
4938         return err;
4939 }
4940
4941 #ifdef CONFIG_QUOTA
4942 static int ext4_statfs_project(struct super_block *sb,
4943                                kprojid_t projid, struct kstatfs *buf)
4944 {
4945         struct kqid qid;
4946         struct dquot *dquot;
4947         u64 limit;
4948         u64 curblock;
4949
4950         qid = make_kqid_projid(projid);
4951         dquot = dqget(sb, qid);
4952         if (IS_ERR(dquot))
4953                 return PTR_ERR(dquot);
4954         spin_lock(&dq_data_lock);
4955
4956         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4957                  dquot->dq_dqb.dqb_bsoftlimit :
4958                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4959         if (limit && buf->f_blocks > limit) {
4960                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4961                 buf->f_blocks = limit;
4962                 buf->f_bfree = buf->f_bavail =
4963                         (buf->f_blocks > curblock) ?
4964                          (buf->f_blocks - curblock) : 0;
4965         }
4966
4967         limit = dquot->dq_dqb.dqb_isoftlimit ?
4968                 dquot->dq_dqb.dqb_isoftlimit :
4969                 dquot->dq_dqb.dqb_ihardlimit;
4970         if (limit && buf->f_files > limit) {
4971                 buf->f_files = limit;
4972                 buf->f_ffree =
4973                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4974                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4975         }
4976
4977         spin_unlock(&dq_data_lock);
4978         dqput(dquot);
4979         return 0;
4980 }
4981 #endif
4982
4983 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4984 {
4985         struct super_block *sb = dentry->d_sb;
4986         struct ext4_sb_info *sbi = EXT4_SB(sb);
4987         struct ext4_super_block *es = sbi->s_es;
4988         ext4_fsblk_t overhead = 0, resv_blocks;
4989         u64 fsid;
4990         s64 bfree;
4991         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4992
4993         if (!test_opt(sb, MINIX_DF))
4994                 overhead = sbi->s_overhead;
4995
4996         buf->f_type = EXT4_SUPER_MAGIC;
4997         buf->f_bsize = sb->s_blocksize;
4998         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4999         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5000                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5001         /* prevent underflow in case that few free space is available */
5002         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5003         buf->f_bavail = buf->f_bfree -
5004                         (ext4_r_blocks_count(es) + resv_blocks);
5005         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5006                 buf->f_bavail = 0;
5007         buf->f_files = le32_to_cpu(es->s_inodes_count);
5008         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5009         buf->f_namelen = EXT4_NAME_LEN;
5010         fsid = le64_to_cpup((void *)es->s_uuid) ^
5011                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5012         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5013         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5014
5015 #ifdef CONFIG_QUOTA
5016         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5017             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5018                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5019 #endif
5020         return 0;
5021 }
5022
5023 /* Helper function for writing quotas on sync - we need to start transaction
5024  * before quota file is locked for write. Otherwise the are possible deadlocks:
5025  * Process 1                         Process 2
5026  * ext4_create()                     quota_sync()
5027  *   jbd2_journal_start()                  write_dquot()
5028  *   dquot_initialize()                         down(dqio_mutex)
5029  *     down(dqio_mutex)                    jbd2_journal_start()
5030  *
5031  */
5032
5033 #ifdef CONFIG_QUOTA
5034
5035 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5036 {
5037         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5038 }
5039
5040 static int ext4_write_dquot(struct dquot *dquot)
5041 {
5042         int ret, err;
5043         handle_t *handle;
5044         struct inode *inode;
5045
5046         inode = dquot_to_inode(dquot);
5047         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5048                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5049         if (IS_ERR(handle))
5050                 return PTR_ERR(handle);
5051         ret = dquot_commit(dquot);
5052         err = ext4_journal_stop(handle);
5053         if (!ret)
5054                 ret = err;
5055         return ret;
5056 }
5057
5058 static int ext4_acquire_dquot(struct dquot *dquot)
5059 {
5060         int ret, err;
5061         handle_t *handle;
5062
5063         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5064                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5065         if (IS_ERR(handle))
5066                 return PTR_ERR(handle);
5067         ret = dquot_acquire(dquot);
5068         err = ext4_journal_stop(handle);
5069         if (!ret)
5070                 ret = err;
5071         return ret;
5072 }
5073
5074 static int ext4_release_dquot(struct dquot *dquot)
5075 {
5076         int ret, err;
5077         handle_t *handle;
5078
5079         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5080                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5081         if (IS_ERR(handle)) {
5082                 /* Release dquot anyway to avoid endless cycle in dqput() */
5083                 dquot_release(dquot);
5084                 return PTR_ERR(handle);
5085         }
5086         ret = dquot_release(dquot);
5087         err = ext4_journal_stop(handle);
5088         if (!ret)
5089                 ret = err;
5090         return ret;
5091 }
5092
5093 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5094 {
5095         struct super_block *sb = dquot->dq_sb;
5096         struct ext4_sb_info *sbi = EXT4_SB(sb);
5097
5098         /* Are we journaling quotas? */
5099         if (ext4_has_feature_quota(sb) ||
5100             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5101                 dquot_mark_dquot_dirty(dquot);
5102                 return ext4_write_dquot(dquot);
5103         } else {
5104                 return dquot_mark_dquot_dirty(dquot);
5105         }
5106 }
5107
5108 static int ext4_write_info(struct super_block *sb, int type)
5109 {
5110         int ret, err;
5111         handle_t *handle;
5112
5113         /* Data block + inode block */
5114         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5115         if (IS_ERR(handle))
5116                 return PTR_ERR(handle);
5117         ret = dquot_commit_info(sb, type);
5118         err = ext4_journal_stop(handle);
5119         if (!ret)
5120                 ret = err;
5121         return ret;
5122 }
5123
5124 /*
5125  * Turn on quotas during mount time - we need to find
5126  * the quota file and such...
5127  */
5128 static int ext4_quota_on_mount(struct super_block *sb, int type)
5129 {
5130         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5131                                         EXT4_SB(sb)->s_jquota_fmt, type);
5132 }
5133
5134 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5135 {
5136         struct ext4_inode_info *ei = EXT4_I(inode);
5137
5138         /* The first argument of lockdep_set_subclass has to be
5139          * *exactly* the same as the argument to init_rwsem() --- in
5140          * this case, in init_once() --- or lockdep gets unhappy
5141          * because the name of the lock is set using the
5142          * stringification of the argument to init_rwsem().
5143          */
5144         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5145         lockdep_set_subclass(&ei->i_data_sem, subclass);
5146 }
5147
5148 /*
5149  * Standard function to be called on quota_on
5150  */
5151 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5152                          struct path *path)
5153 {
5154         int err;
5155
5156         if (!test_opt(sb, QUOTA))
5157                 return -EINVAL;
5158
5159         /* Quotafile not on the same filesystem? */
5160         if (path->dentry->d_sb != sb)
5161                 return -EXDEV;
5162         /* Journaling quota? */
5163         if (EXT4_SB(sb)->s_qf_names[type]) {
5164                 /* Quotafile not in fs root? */
5165                 if (path->dentry->d_parent != sb->s_root)
5166                         ext4_msg(sb, KERN_WARNING,
5167                                 "Quota file not on filesystem root. "
5168                                 "Journaled quota will not work");
5169         }
5170
5171         /*
5172          * When we journal data on quota file, we have to flush journal to see
5173          * all updates to the file when we bypass pagecache...
5174          */
5175         if (EXT4_SB(sb)->s_journal &&
5176             ext4_should_journal_data(d_inode(path->dentry))) {
5177                 /*
5178                  * We don't need to lock updates but journal_flush() could
5179                  * otherwise be livelocked...
5180                  */
5181                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5182                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5183                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5184                 if (err)
5185                         return err;
5186         }
5187         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5188         err = dquot_quota_on(sb, type, format_id, path);
5189         if (err)
5190                 lockdep_set_quota_inode(path->dentry->d_inode,
5191                                              I_DATA_SEM_NORMAL);
5192         return err;
5193 }
5194
5195 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5196                              unsigned int flags)
5197 {
5198         int err;
5199         struct inode *qf_inode;
5200         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5201                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5202                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5203                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5204         };
5205
5206         BUG_ON(!ext4_has_feature_quota(sb));
5207
5208         if (!qf_inums[type])
5209                 return -EPERM;
5210
5211         qf_inode = ext4_iget(sb, qf_inums[type]);
5212         if (IS_ERR(qf_inode)) {
5213                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5214                 return PTR_ERR(qf_inode);
5215         }
5216
5217         /* Don't account quota for quota files to avoid recursion */
5218         qf_inode->i_flags |= S_NOQUOTA;
5219         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5220         err = dquot_enable(qf_inode, type, format_id, flags);
5221         iput(qf_inode);
5222         if (err)
5223                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5224
5225         return err;
5226 }
5227
5228 /* Enable usage tracking for all quota types. */
5229 static int ext4_enable_quotas(struct super_block *sb)
5230 {
5231         int type, err = 0;
5232         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5233                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5234                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5235                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5236         };
5237
5238         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5239         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5240                 if (qf_inums[type]) {
5241                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5242                                                 DQUOT_USAGE_ENABLED);
5243                         if (err) {
5244                                 ext4_warning(sb,
5245                                         "Failed to enable quota tracking "
5246                                         "(type=%d, err=%d). Please run "
5247                                         "e2fsck to fix.", type, err);
5248                                 return err;
5249                         }
5250                 }
5251         }
5252         return 0;
5253 }
5254
5255 static int ext4_quota_off(struct super_block *sb, int type)
5256 {
5257         struct inode *inode = sb_dqopt(sb)->files[type];
5258         handle_t *handle;
5259
5260         /* Force all delayed allocation blocks to be allocated.
5261          * Caller already holds s_umount sem */
5262         if (test_opt(sb, DELALLOC))
5263                 sync_filesystem(sb);
5264
5265         if (!inode)
5266                 goto out;
5267
5268         /* Update modification times of quota files when userspace can
5269          * start looking at them */
5270         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5271         if (IS_ERR(handle))
5272                 goto out;
5273         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5274         ext4_mark_inode_dirty(handle, inode);
5275         ext4_journal_stop(handle);
5276
5277 out:
5278         return dquot_quota_off(sb, type);
5279 }
5280
5281 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5282  * acquiring the locks... As quota files are never truncated and quota code
5283  * itself serializes the operations (and no one else should touch the files)
5284  * we don't have to be afraid of races */
5285 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5286                                size_t len, loff_t off)
5287 {
5288         struct inode *inode = sb_dqopt(sb)->files[type];
5289         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5290         int offset = off & (sb->s_blocksize - 1);
5291         int tocopy;
5292         size_t toread;
5293         struct buffer_head *bh;
5294         loff_t i_size = i_size_read(inode);
5295
5296         if (off > i_size)
5297                 return 0;
5298         if (off+len > i_size)
5299                 len = i_size-off;
5300         toread = len;
5301         while (toread > 0) {
5302                 tocopy = sb->s_blocksize - offset < toread ?
5303                                 sb->s_blocksize - offset : toread;
5304                 bh = ext4_bread(NULL, inode, blk, 0);
5305                 if (IS_ERR(bh))
5306                         return PTR_ERR(bh);
5307                 if (!bh)        /* A hole? */
5308                         memset(data, 0, tocopy);
5309                 else
5310                         memcpy(data, bh->b_data+offset, tocopy);
5311                 brelse(bh);
5312                 offset = 0;
5313                 toread -= tocopy;
5314                 data += tocopy;
5315                 blk++;
5316         }
5317         return len;
5318 }
5319
5320 /* Write to quotafile (we know the transaction is already started and has
5321  * enough credits) */
5322 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5323                                 const char *data, size_t len, loff_t off)
5324 {
5325         struct inode *inode = sb_dqopt(sb)->files[type];
5326         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5327         int err, offset = off & (sb->s_blocksize - 1);
5328         int retries = 0;
5329         struct buffer_head *bh;
5330         handle_t *handle = journal_current_handle();
5331
5332         if (EXT4_SB(sb)->s_journal && !handle) {
5333                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5334                         " cancelled because transaction is not started",
5335                         (unsigned long long)off, (unsigned long long)len);
5336                 return -EIO;
5337         }
5338         /*
5339          * Since we account only one data block in transaction credits,
5340          * then it is impossible to cross a block boundary.
5341          */
5342         if (sb->s_blocksize - offset < len) {
5343                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5344                         " cancelled because not block aligned",
5345                         (unsigned long long)off, (unsigned long long)len);
5346                 return -EIO;
5347         }
5348
5349         do {
5350                 bh = ext4_bread(handle, inode, blk,
5351                                 EXT4_GET_BLOCKS_CREATE |
5352                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5353         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5354                  ext4_should_retry_alloc(inode->i_sb, &retries));
5355         if (IS_ERR(bh))
5356                 return PTR_ERR(bh);
5357         if (!bh)
5358                 goto out;
5359         BUFFER_TRACE(bh, "get write access");
5360         err = ext4_journal_get_write_access(handle, bh);
5361         if (err) {
5362                 brelse(bh);
5363                 return err;
5364         }
5365         lock_buffer(bh);
5366         memcpy(bh->b_data+offset, data, len);
5367         flush_dcache_page(bh->b_page);
5368         unlock_buffer(bh);
5369         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5370         brelse(bh);
5371 out:
5372         if (inode->i_size < off + len) {
5373                 i_size_write(inode, off + len);
5374                 EXT4_I(inode)->i_disksize = inode->i_size;
5375                 ext4_mark_inode_dirty(handle, inode);
5376         }
5377         return len;
5378 }
5379
5380 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5381 {
5382         const struct quota_format_ops   *ops;
5383
5384         if (!sb_has_quota_loaded(sb, qid->type))
5385                 return -ESRCH;
5386         ops = sb_dqopt(sb)->ops[qid->type];
5387         if (!ops || !ops->get_next_id)
5388                 return -ENOSYS;
5389         return dquot_get_next_id(sb, qid);
5390 }
5391 #endif
5392
5393 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5394                        const char *dev_name, void *data)
5395 {
5396         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5397 }
5398
5399 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5400 static inline void register_as_ext2(void)
5401 {
5402         int err = register_filesystem(&ext2_fs_type);
5403         if (err)
5404                 printk(KERN_WARNING
5405                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5406 }
5407
5408 static inline void unregister_as_ext2(void)
5409 {
5410         unregister_filesystem(&ext2_fs_type);
5411 }
5412
5413 static inline int ext2_feature_set_ok(struct super_block *sb)
5414 {
5415         if (ext4_has_unknown_ext2_incompat_features(sb))
5416                 return 0;
5417         if (sb->s_flags & MS_RDONLY)
5418                 return 1;
5419         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5420                 return 0;
5421         return 1;
5422 }
5423 #else
5424 static inline void register_as_ext2(void) { }
5425 static inline void unregister_as_ext2(void) { }
5426 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5427 #endif
5428
5429 static inline void register_as_ext3(void)
5430 {
5431         int err = register_filesystem(&ext3_fs_type);
5432         if (err)
5433                 printk(KERN_WARNING
5434                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5435 }
5436
5437 static inline void unregister_as_ext3(void)
5438 {
5439         unregister_filesystem(&ext3_fs_type);
5440 }
5441
5442 static inline int ext3_feature_set_ok(struct super_block *sb)
5443 {
5444         if (ext4_has_unknown_ext3_incompat_features(sb))
5445                 return 0;
5446         if (!ext4_has_feature_journal(sb))
5447                 return 0;
5448         if (sb->s_flags & MS_RDONLY)
5449                 return 1;
5450         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5451                 return 0;
5452         return 1;
5453 }
5454
5455 static struct file_system_type ext4_fs_type = {
5456         .owner          = THIS_MODULE,
5457         .name           = "ext4",
5458         .mount          = ext4_mount,
5459         .kill_sb        = kill_block_super,
5460         .fs_flags       = FS_REQUIRES_DEV,
5461 };
5462 MODULE_ALIAS_FS("ext4");
5463
5464 /* Shared across all ext4 file systems */
5465 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5466
5467 static int __init ext4_init_fs(void)
5468 {
5469         int i, err;
5470
5471         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5472         ext4_li_info = NULL;
5473         mutex_init(&ext4_li_mtx);
5474
5475         /* Build-time check for flags consistency */
5476         ext4_check_flag_values();
5477
5478         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5479                 init_waitqueue_head(&ext4__ioend_wq[i]);
5480
5481         err = ext4_init_es();
5482         if (err)
5483                 return err;
5484
5485         err = ext4_init_pageio();
5486         if (err)
5487                 goto out5;
5488
5489         err = ext4_init_system_zone();
5490         if (err)
5491                 goto out4;
5492
5493         err = ext4_init_sysfs();
5494         if (err)
5495                 goto out3;
5496
5497         err = ext4_init_mballoc();
5498         if (err)
5499                 goto out2;
5500         err = init_inodecache();
5501         if (err)
5502                 goto out1;
5503         register_as_ext3();
5504         register_as_ext2();
5505         err = register_filesystem(&ext4_fs_type);
5506         if (err)
5507                 goto out;
5508
5509         return 0;
5510 out:
5511         unregister_as_ext2();
5512         unregister_as_ext3();
5513         destroy_inodecache();
5514 out1:
5515         ext4_exit_mballoc();
5516 out2:
5517         ext4_exit_sysfs();
5518 out3:
5519         ext4_exit_system_zone();
5520 out4:
5521         ext4_exit_pageio();
5522 out5:
5523         ext4_exit_es();
5524
5525         return err;
5526 }
5527
5528 static void __exit ext4_exit_fs(void)
5529 {
5530         ext4_destroy_lazyinit_thread();
5531         unregister_as_ext2();
5532         unregister_as_ext3();
5533         unregister_filesystem(&ext4_fs_type);
5534         destroy_inodecache();
5535         ext4_exit_mballoc();
5536         ext4_exit_sysfs();
5537         ext4_exit_system_zone();
5538         ext4_exit_pageio();
5539         ext4_exit_es();
5540 }
5541
5542 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5543 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5544 MODULE_LICENSE("GPL");
5545 module_init(ext4_init_fs)
5546 module_exit(ext4_exit_fs)