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| author | Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> | 2009-06-08 12:41:35 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-06-08 12:41:35 -0400 |
| commit | 9aee2286071c23c535fe9928eec1a26e0bcf256d (patch) | |
| tree | e0518acaa75c1399ffcf67ca74a54d5a9488296b /fs/ext4 | |
| parent | f8514083cd61daef12fba5ef883ad9352c450428 (diff) | |
| download | lwn-9aee2286071c23c535fe9928eec1a26e0bcf256d.tar.gz lwn-9aee2286071c23c535fe9928eec1a26e0bcf256d.zip | |
ext4: fix dx_map_entry to support 256k directory blocks
The dx_map_entry structure doesn't support over 64KB block size by
current usage of its member("offs"). Because "offs" treats an offset
of copies of the ext4_dir_entry_2 structure as is. This member size is
16 bits. But real offset for over 64KB(256KB) block size needs 18
bits. However, real offset keeps 4 byte boundary, so lower 2 bits is
not used.
Therefore, we do the following to fix this limitation:
For "store":
we divide the real offset by 4 and then store this result to "offs"
member.
For "use":
we multiply "offs" member by 4 and then use this result
as real offset.
Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/namei.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index f2bc160463b7..07eb6649e4fa 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -749,7 +749,7 @@ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, ext4fs_dirhash(de->name, de->name_len, &h); map_tail--; map_tail->hash = h.hash; - map_tail->offs = (u16) ((char *) de - base); + map_tail->offs = ((char *) de - base)>>2; map_tail->size = le16_to_cpu(de->rec_len); count++; cond_resched(); @@ -1147,7 +1147,8 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, unsigned rec_len = 0; while (count--) { - struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs); + struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) + (from + (map->offs<<2)); rec_len = EXT4_DIR_REC_LEN(de->name_len); memcpy (to, de, rec_len); ((struct ext4_dir_entry_2 *) to)->rec_len = |