fs/sysv/inode.c

   1 /*
   2  *  linux/fs/sysv/inode.c
   3  *
   4  *  minix/inode.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  xenix/inode.c
   8  *  Copyright (C) 1992  Doug Evans
   9  *
  10  *  coh/inode.c
  11  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
  12  *
  13  *  sysv/inode.c
  14  *  Copyright (C) 1993  Paul B. Monday
  15  *
  16  *  sysv/inode.c
  17  *  Copyright (C) 1993  Bruno Haible
  18  *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
  19  *
  20  *  This file contains code for allocating/freeing inodes and for read/writing
  21  *  the superblock.
  22  */
  23
  24 #include <linux/highuid.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/vfs.h>
  29 #include <linux/writeback.h>
  30 #include <linux/namei.h>
  31 #include <asm/byteorder.h>
  32 #include "sysv.h"
  33
  34 static int sysv_sync_fs(struct super_block *sb, int wait)
  35 {
  36         struct sysv_sb_info *sbi = SYSV_SB(sb);
  37         unsigned long time = get_seconds(), old_time;
  38
  39         lock_super(sb);
  40
  41         /*
  42          * If we are going to write out the super block,
  43          * then attach current time stamp.
  44          * But if the filesystem was marked clean, keep it clean.
  45          */
  46         sb->s_dirt = 0;
  47         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  48         if (sbi->s_type == FSTYPE_SYSV4) {
  49                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  50                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  51                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  52                 mark_buffer_dirty(sbi->s_bh2);
  53         }
  54
  55         unlock_super(sb);
  56
  57         return 0;
  58 }
  59
  60 static void sysv_write_super(struct super_block *sb)
  61 {
  62         if (!(sb->s_flags & MS_RDONLY))
  63                 sysv_sync_fs(sb, 1);
  64         else
  65                 sb->s_dirt = 0;
  66 }
  67
  68 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  69 {
  70         struct sysv_sb_info *sbi = SYSV_SB(sb);
  71         lock_super(sb);
  72         if (sbi->s_forced_ro)
  73                 *flags |= MS_RDONLY;
  74         if (*flags & MS_RDONLY)
  75                 sysv_write_super(sb);
  76         unlock_super(sb);
  77         return 0;
  78 }
  79
  80 static void sysv_put_super(struct super_block *sb)
  81 {
  82         struct sysv_sb_info *sbi = SYSV_SB(sb);
  83
  84         if (sb->s_dirt)
  85                 sysv_write_super(sb);
  86
  87         if (!(sb->s_flags & MS_RDONLY)) {
  88                 /* XXX ext2 also updates the state here */
  89                 mark_buffer_dirty(sbi->s_bh1);
  90                 if (sbi->s_bh1 != sbi->s_bh2)
  91                         mark_buffer_dirty(sbi->s_bh2);
  92         }
  93
  94         brelse(sbi->s_bh1);
  95         if (sbi->s_bh1 != sbi->s_bh2)
  96                 brelse(sbi->s_bh2);
  97
  98         kfree(sbi);
  99 }
 100
 101 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
 102 {
 103         struct super_block *sb = dentry->d_sb;
 104         struct sysv_sb_info *sbi = SYSV_SB(sb);
 105         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 106
 107         buf->f_type = sb->s_magic;
 108         buf->f_bsize = sb->s_blocksize;
 109         buf->f_blocks = sbi->s_ndatazones;
 110         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
 111         buf->f_files = sbi->s_ninodes;
 112         buf->f_ffree = sysv_count_free_inodes(sb);
 113         buf->f_namelen = SYSV_NAMELEN;
 114         buf->f_fsid.val[0] = (u32)id;
 115         buf->f_fsid.val[1] = (u32)(id >> 32);
 116         return 0;
 117 }
 118
 119 /*
 120  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 121  */
 122 static inline void read3byte(struct sysv_sb_info *sbi,
 123         unsigned char * from, unsigned char * to)
 124 {
 125         if (sbi->s_bytesex == BYTESEX_PDP) {
 126                 to[0] = from[0];
 127                 to[1] = 0;
 128                 to[2] = from[1];
 129                 to[3] = from[2];
 130         } else if (sbi->s_bytesex == BYTESEX_LE) {
 131                 to[0] = from[0];
 132                 to[1] = from[1];
 133                 to[2] = from[2];
 134                 to[3] = 0;
 135         } else {
 136                 to[0] = 0;
 137                 to[1] = from[0];
 138                 to[2] = from[1];
 139                 to[3] = from[2];
 140         }
 141 }
 142
 143 static inline void write3byte(struct sysv_sb_info *sbi,
 144         unsigned char * from, unsigned char * to)
 145 {
 146         if (sbi->s_bytesex == BYTESEX_PDP) {
 147                 to[0] = from[0];
 148                 to[1] = from[2];
 149                 to[2] = from[3];
 150         } else if (sbi->s_bytesex == BYTESEX_LE) {
 151                 to[0] = from[0];
 152                 to[1] = from[1];
 153                 to[2] = from[2];
 154         } else {
 155                 to[0] = from[1];
 156                 to[1] = from[2];
 157                 to[2] = from[3];
 158         }
 159 }
 160
 161 static const struct inode_operations sysv_symlink_inode_operations = {
 162         .readlink       = generic_readlink,
 163         .follow_link    = page_follow_link_light,
 164         .put_link       = page_put_link,
 165         .getattr        = sysv_getattr,
 166 };
 167
 168 void sysv_set_inode(struct inode *inode, dev_t rdev)
 169 {
 170         if (S_ISREG(inode->i_mode)) {
 171                 inode->i_op = &sysv_file_inode_operations;
 172                 inode->i_fop = &sysv_file_operations;
 173                 inode->i_mapping->a_ops = &sysv_aops;
 174         } else if (S_ISDIR(inode->i_mode)) {
 175                 inode->i_op = &sysv_dir_inode_operations;
 176                 inode->i_fop = &sysv_dir_operations;
 177                 inode->i_mapping->a_ops = &sysv_aops;
 178         } else if (S_ISLNK(inode->i_mode)) {
 179                 if (inode->i_blocks) {
 180                         inode->i_op = &sysv_symlink_inode_operations;
 181                         inode->i_mapping->a_ops = &sysv_aops;
 182                 } else {
 183                         inode->i_op = &sysv_fast_symlink_inode_operations;
 184                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 185                                 sizeof(SYSV_I(inode)->i_data) - 1);
 186                 }
 187         } else
 188                 init_special_inode(inode, inode->i_mode, rdev);
 189 }
 190
 191 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 192 {
 193         struct sysv_sb_info * sbi = SYSV_SB(sb);
 194         struct buffer_head * bh;
 195         struct sysv_inode * raw_inode;
 196         struct sysv_inode_info * si;
 197         struct inode *inode;
 198         unsigned int block;
 199
 200         if (!ino || ino > sbi->s_ninodes) {
 201                 printk("Bad inode number on dev %s: %d is out of range\n",
 202                        sb->s_id, ino);
 203                 return ERR_PTR(-EIO);
 204         }
 205
 206         inode = iget_locked(sb, ino);
 207         if (!inode)
 208                 return ERR_PTR(-ENOMEM);
 209         if (!(inode->i_state & I_NEW))
 210                 return inode;
 211
 212         raw_inode = sysv_raw_inode(sb, ino, &bh);
 213         if (!raw_inode) {
 214                 printk("Major problem: unable to read inode from dev %s\n",
 215                        inode->i_sb->s_id);
 216                 goto bad_inode;
 217         }
 218         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 219         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 220         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 221         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 222         set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
 223         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 224         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 225         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 226         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 227         inode->i_ctime.tv_nsec = 0;
 228         inode->i_atime.tv_nsec = 0;
 229         inode->i_mtime.tv_nsec = 0;
 230         inode->i_blocks = 0;
 231
 232         si = SYSV_I(inode);
 233         for (block = 0; block < 10+1+1+1; block++)
 234                 read3byte(sbi, &raw_inode->i_data[3*block],
 235                                 (u8 *)&si->i_data[block]);
 236         brelse(bh);
 237         si->i_dir_start_lookup = 0;
 238         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 239                 sysv_set_inode(inode,
 240                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 241         else
 242                 sysv_set_inode(inode, 0);
 243         unlock_new_inode(inode);
 244         return inode;
 245
 246 bad_inode:
 247         iget_failed(inode);
 248         return ERR_PTR(-EIO);
 249 }
 250
 251 static int __sysv_write_inode(struct inode *inode, int wait)
 252 {
 253         struct super_block * sb = inode->i_sb;
 254         struct sysv_sb_info * sbi = SYSV_SB(sb);
 255         struct buffer_head * bh;
 256         struct sysv_inode * raw_inode;
 257         struct sysv_inode_info * si;
 258         unsigned int ino, block;
 259         int err = 0;
 260
 261         ino = inode->i_ino;
 262         if (!ino || ino > sbi->s_ninodes) {
 263                 printk("Bad inode number on dev %s: %d is out of range\n",
 264                        inode->i_sb->s_id, ino);
 265                 return -EIO;
 266         }
 267         raw_inode = sysv_raw_inode(sb, ino, &bh);
 268         if (!raw_inode) {
 269                 printk("unable to read i-node block\n");
 270                 return -EIO;
 271         }
 272
 273         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 274         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 275         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 276         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 277         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 278         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 279         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 280         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 281
 282         si = SYSV_I(inode);
 283         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 284                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 285         for (block = 0; block < 10+1+1+1; block++)
 286                 write3byte(sbi, (u8 *)&si->i_data[block],
 287                         &raw_inode->i_data[3*block]);
 288         mark_buffer_dirty(bh);
 289         if (wait) {
 290                 sync_dirty_buffer(bh);
 291                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 292                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 293                                 sb->s_id, ino);
 294                         err = -EIO;
 295                 }
 296         }
 297         brelse(bh);
 298         return 0;
 299 }
 300
 301 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
 302 {
 303         return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 304 }
 305
 306 int sysv_sync_inode(struct inode *inode)
 307 {
 308         return __sysv_write_inode(inode, 1);
 309 }
 310
 311 static void sysv_evict_inode(struct inode *inode)
 312 {
 313         truncate_inode_pages(&inode->i_data, 0);
 314         if (!inode->i_nlink) {
 315                 inode->i_size = 0;
 316                 sysv_truncate(inode);
 317         }
 318         invalidate_inode_buffers(inode);
 319         end_writeback(inode);
 320         if (!inode->i_nlink)
 321                 sysv_free_inode(inode);
 322 }
 323
 324 static struct kmem_cache *sysv_inode_cachep;
 325
 326 static struct inode *sysv_alloc_inode(struct super_block *sb)
 327 {
 328         struct sysv_inode_info *si;
 329
 330         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 331         if (!si)
 332                 return NULL;
 333         return &si->vfs_inode;
 334 }
 335
 336 static void sysv_i_callback(struct rcu_head *head)
 337 {
 338         struct inode *inode = container_of(head, struct inode, i_rcu);
 339         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 340 }
 341
 342 static void sysv_destroy_inode(struct inode *inode)
 343 {
 344         call_rcu(&inode->i_rcu, sysv_i_callback);
 345 }
 346
 347 static void init_once(void *p)
 348 {
 349         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 350
 351         inode_init_once(&si->vfs_inode);
 352 }
 353
 354 const struct super_operations sysv_sops = {
 355         .alloc_inode    = sysv_alloc_inode,
 356         .destroy_inode  = sysv_destroy_inode,
 357         .write_inode    = sysv_write_inode,
 358         .evict_inode    = sysv_evict_inode,
 359         .put_super      = sysv_put_super,
 360         .write_super    = sysv_write_super,
 361         .sync_fs        = sysv_sync_fs,
 362         .remount_fs     = sysv_remount,
 363         .statfs         = sysv_statfs,
 364 };
 365
 366 int __init sysv_init_icache(void)
 367 {
 368         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 369                         sizeof(struct sysv_inode_info), 0,
 370                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 371                         init_once);
 372         if (!sysv_inode_cachep)
 373                 return -ENOMEM;
 374         return 0;
 375 }
 376
 377 void sysv_destroy_icache(void)
 378 {
 379         kmem_cache_destroy(sysv_inode_cachep);
 380 }