ext4: add largedir feature

This INCOMPAT_LARGEDIR feature allows larger directories to be created
in ldiskfs, both with directory sizes over 2GB and and a maximum htree
depth of 3 instead of the current limit of 2. These features are needed
in order to exceed the current limit of approximately 10M entries in a
single directory.

This patch was originally written by Yang Sheng to support the Lustre server.

[ Bumped the credits needed to update an indexed directory -- tytso ]

Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Signed-off-by: Artem Blagodarenko <artem.blagodarenko@seagate.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3219154..f17a4e7 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1800,7 +1800,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,              ENCRYPT)
                                         EXT4_FEATURE_INCOMPAT_MMP | \
                                         EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
                                         EXT4_FEATURE_INCOMPAT_ENCRYPT | \
-                                        EXT4_FEATURE_INCOMPAT_CSUM_SEED)
+                                        EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
+                                        EXT4_FEATURE_INCOMPAT_LARGEDIR)
 #define EXT4_FEATURE_RO_COMPAT_SUPP    (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
                                         EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
                                         EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
@@ -2126,6 +2127,16 @@ ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
  */
 #define ERR_BAD_DX_DIR (-(MAX_ERRNO - 1))
 
+/* htree levels for ext4 */
+#define        EXT4_HTREE_LEVEL_COMPAT 2
+#define        EXT4_HTREE_LEVEL        3
+
+static inline int ext4_dir_htree_level(struct super_block *sb)
+{
+       return ext4_has_feature_largedir(sb) ?
+               EXT4_HTREE_LEVEL : EXT4_HTREE_LEVEL_COMPAT;
+}
+
 /*
  * Timeout and state flag for lazy initialization inode thread.
  */
@@ -2756,13 +2767,15 @@ static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
        es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
 }
 
-static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
+static inline loff_t ext4_isize(struct super_block *sb,
+                               struct ext4_inode *raw_inode)
 {
-       if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
+       if (ext4_has_feature_largedir(sb) ||
+           S_ISREG(le16_to_cpu(raw_inode->i_mode)))
                return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
                        le32_to_cpu(raw_inode->i_size_lo);
-       else
-               return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
+
+       return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
 }
 
 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)

diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index f976111..5e61e46 100644 (file)
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -77,7 +77,14 @@
 
 #define EXT4_RESERVE_TRANS_BLOCKS      12U
 
-#define EXT4_INDEX_EXTRA_TRANS_BLOCKS  8
+/*
+ * Number of credits needed if we need to insert an entry into a
+ * directory.  For each new index block, we need 4 blocks (old index
+ * block, new index block, bitmap block, bg summary).  For normal
+ * htree directories there are 2 levels; if the largedir feature
+ * enabled it's 3 levels.
+ */
+#define EXT4_INDEX_EXTRA_TRANS_BLOCKS  12U
 
 #ifdef CONFIG_QUOTA
 /* Amount of blocks needed for quota update - we know that the structure was

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5cf82d0..47604d1 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4712,7 +4712,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
        if (ext4_has_feature_64bit(sb))
                ei->i_file_acl |=
                        ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
-       inode->i_size = ext4_isize(raw_inode);
+       inode->i_size = ext4_isize(sb, raw_inode);
        if ((size = i_size_read(inode)) < 0) {
                EXT4_ERROR_INODE(inode, "bad i_size value: %lld", size);
                ret = -EFSCORRUPTED;
@@ -5037,7 +5037,7 @@ static int ext4_do_update_inode(handle_t *handle,
                raw_inode->i_file_acl_high =
                        cpu_to_le16(ei->i_file_acl >> 32);
        raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
-       if (ei->i_disksize != ext4_isize(raw_inode)) {
+       if (ei->i_disksize != ext4_isize(inode->i_sb, raw_inode)) {
                ext4_isize_set(raw_inode, ei->i_disksize);
                need_datasync = 1;
        }

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 404256c..423e1f7 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -513,7 +513,7 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 
 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 {
-       return le32_to_cpu(entry->block) & 0x00ffffff;
+       return le32_to_cpu(entry->block) & 0x0fffffff;
 }
 
 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
@@ -739,6 +739,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
        struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
        u32 hash;
 
+       memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
        frame->bh = ext4_read_dirblock(dir, 0, INDEX);
        if (IS_ERR(frame->bh))
                return (struct dx_frame *) frame->bh;
@@ -768,9 +769,15 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
        }
 
        indirect = root->info.indirect_levels;
-       if (indirect > 1) {
-               ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
-                                  root->info.indirect_levels);
+       if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
+               ext4_warning(dir->i_sb,
+                            "Directory (ino: %lu) htree depth %#06x exceed"
+                            "supported value", dir->i_ino,
+                            ext4_dir_htree_level(dir->i_sb));
+               if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
+                       ext4_warning(dir->i_sb, "Enable large directory "
+                                               "feature to access it");
+               }
                goto fail;
        }
 
@@ -859,12 +866,19 @@ fail:
 
 static void dx_release(struct dx_frame *frames)
 {
+       struct dx_root_info *info;
+       int i;
+
        if (frames[0].bh == NULL)
                return;
 
-       if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
-               brelse(frames[1].bh);
-       brelse(frames[0].bh);
+       info = &((struct dx_root *)frames[0].bh->b_data)->info;
+       for (i = 0; i <= info->indirect_levels; i++) {
+               if (frames[i].bh == NULL)
+                       break;
+               brelse(frames[i].bh);
+               frames[i].bh = NULL;
+       }
 }
 
 /*
@@ -1050,7 +1064,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 {
        struct dx_hash_info hinfo;
        struct ext4_dir_entry_2 *de;
-       struct dx_frame frames[2], *frame;
+       struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
        struct inode *dir;
        ext4_lblk_t block;
        int count = 0;
@@ -1485,7 +1499,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
                        struct ext4_dir_entry_2 **res_dir)
 {
        struct super_block * sb = dir->i_sb;
-       struct dx_frame frames[2], *frame;
+       struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
        struct buffer_head *bh;
        ext4_lblk_t block;
        int retval;
@@ -1889,7 +1903,7 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
         */
        dir->i_mtime = dir->i_ctime = current_time(dir);
        ext4_update_dx_flag(dir);
-       dir->i_version++;
+       inode_inc_iversion(dir);
        ext4_mark_inode_dirty(handle, dir);
        BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
        err = ext4_handle_dirty_dirent_node(handle, dir, bh);
@@ -1908,7 +1922,7 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 {
        struct buffer_head *bh2;
        struct dx_root  *root;
-       struct dx_frame frames[2], *frame;
+       struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
        struct dx_entry *entries;
        struct ext4_dir_entry_2 *de, *de2;
        struct ext4_dir_entry_tail *t;
@@ -2127,13 +2141,16 @@ out:
 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
                             struct inode *dir, struct inode *inode)
 {
-       struct dx_frame frames[2], *frame;
+       struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
        struct dx_entry *entries, *at;
        struct buffer_head *bh;
        struct super_block *sb = dir->i_sb;
        struct ext4_dir_entry_2 *de;
+       int restart;
        int err;
 
+again:
+       restart = 0;
        frame = dx_probe(fname, dir, NULL, frames);
        if (IS_ERR(frame))
                return PTR_ERR(frame);
@@ -2155,24 +2172,44 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
        if (err != -ENOSPC)
                goto cleanup;
 
+       err = 0;
        /* Block full, should compress but for now just split */
        dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
                       dx_get_count(entries), dx_get_limit(entries)));
        /* Need to split index? */
        if (dx_get_count(entries) == dx_get_limit(entries)) {
                ext4_lblk_t newblock;
-               unsigned icount = dx_get_count(entries);
-               int levels = frame - frames;
+               int levels = frame - frames + 1;
+               unsigned int icount;
+               int add_level = 1;
                struct dx_entry *entries2;
                struct dx_node *node2;
                struct buffer_head *bh2;
 
-               if (levels && (dx_get_count(frames->entries) ==
-                              dx_get_limit(frames->entries))) {
-                       ext4_warning_inode(dir, "Directory index full!");
+               while (frame > frames) {
+                       if (dx_get_count((frame - 1)->entries) <
+                           dx_get_limit((frame - 1)->entries)) {
+                               add_level = 0;
+                               break;
+                       }
+                       frame--; /* split higher index block */
+                       at = frame->at;
+                       entries = frame->entries;
+                       restart = 1;
+               }
+               if (add_level && levels == ext4_dir_htree_level(sb)) {
+                       ext4_warning(sb, "Directory (ino: %lu) index full, "
+                                        "reach max htree level :%d",
+                                        dir->i_ino, levels);
+                       if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
+                               ext4_warning(sb, "Large directory feature is "
+                                                "not enabled on this "
+                                                "filesystem");
+                       }
                        err = -ENOSPC;
                        goto cleanup;
                }
+               icount = dx_get_count(entries);
                bh2 = ext4_append(handle, dir, &newblock);
                if (IS_ERR(bh2)) {
                        err = PTR_ERR(bh2);
@@ -2187,7 +2224,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
                err = ext4_journal_get_write_access(handle, frame->bh);
                if (err)
                        goto journal_error;
-               if (levels) {
+               if (!add_level) {
                        unsigned icount1 = icount/2, icount2 = icount - icount1;
                        unsigned hash2 = dx_get_hash(entries + icount1);
                        dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
@@ -2195,7 +2232,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 
                        BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
                        err = ext4_journal_get_write_access(handle,
-                                                            frames[0].bh);
+                                                            (frame - 1)->bh);
                        if (err)
                                goto journal_error;
 
@@ -2211,17 +2248,25 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
                                frame->entries = entries = entries2;
                                swap(frame->bh, bh2);
                        }
-                       dx_insert_block(frames + 0, hash2, newblock);
-                       dxtrace(dx_show_index("node", frames[1].entries));
+                       dx_insert_block((frame - 1), hash2, newblock);
+                       dxtrace(dx_show_index("node", frame->entries));
                        dxtrace(dx_show_index("node",
                               ((struct dx_node *) bh2->b_data)->entries));
                        err = ext4_handle_dirty_dx_node(handle, dir, bh2);
                        if (err)
                                goto journal_error;
                        brelse (bh2);
+                       err = ext4_handle_dirty_dx_node(handle, dir,
+                                                  (frame - 1)->bh);
+                       if (err)
+                               goto journal_error;
+                       if (restart) {
+                               err = ext4_handle_dirty_dx_node(handle, dir,
+                                                          frame->bh);
+                               goto journal_error;
+                       }
                } else {
-                       dxtrace(printk(KERN_DEBUG
-                                      "Creating second level index...\n"));
+                       struct dx_root *dxroot;
                        memcpy((char *) entries2, (char *) entries,
                               icount * sizeof(struct dx_entry));
                        dx_set_limit(entries2, dx_node_limit(dir));
@@ -2229,22 +2274,18 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
                        /* Set up root */
                        dx_set_count(entries, 1);
                        dx_set_block(entries + 0, newblock);
-                       ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
-
-                       /* Add new access path frame */
-                       frame = frames + 1;
-                       frame->at = at = at - entries + entries2;
-                       frame->entries = entries = entries2;
-                       frame->bh = bh2;
-                       err = ext4_journal_get_write_access(handle,
-                                                            frame->bh);
+                       dxroot = (struct dx_root *)frames[0].bh->b_data;
+                       dxroot->info.indirect_levels += 1;
+                       dxtrace(printk(KERN_DEBUG
+                                      "Creating %d level index...\n",
+                                      info->indirect_levels));
+                       err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
                        if (err)
                                goto journal_error;
-               }
-               err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
-               if (err) {
-                       ext4_std_error(inode->i_sb, err);
-                       goto cleanup;
+                       err = ext4_handle_dirty_dx_node(handle, dir, bh2);
+                       brelse(bh2);
+                       restart = 1;
+                       goto journal_error;
                }
        }
        de = do_split(handle, dir, &bh, frame, &fname->hinfo);
@@ -2256,10 +2297,15 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
        goto cleanup;
 
 journal_error:
-       ext4_std_error(dir->i_sb, err);
+       ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
 cleanup:
        brelse(bh);
        dx_release(frames);
+       /* @restart is true means htree-path has been changed, we need to
+        * repeat dx_probe() to find out valid htree-path
+        */
+       if (restart && err == 0)
+               goto again;
        return err;
 }
 
@@ -2296,7 +2342,7 @@ int ext4_generic_delete_entry(handle_t *handle,
                                        blocksize);
                        else
                                de->inode = 0;
-                       dir->i_version++;
+                       inode_inc_iversion(dir);
                        return 0;
                }
                i += ext4_rec_len_from_disk(de->rec_len, blocksize);