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| author | Theodore Ts'o <tytso@mit.edu> | 2010-04-20 16:51:59 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2010-04-20 16:51:59 -0400 |
| commit | b90f687018e6d6c77d981b09203780f7001407e5 (patch) | |
| tree | d2e2b36b4d88d2098000fcb56cc56e5d2e74fdf1 /fs/ext4/mballoc.c | |
| parent | fd2dd9fbaf9e498ec63eef298921e36556f7214c (diff) | |
| download | lwn-b90f687018e6d6c77d981b09203780f7001407e5.tar.gz lwn-b90f687018e6d6c77d981b09203780f7001407e5.zip | |
ext4: Issue the discard operation *before* releasing the blocks to be reused
Otherwise, we can end up having data corruption because the blocks
could get reused and then discarded!
https://bugzilla.kernel.org/show_bug.cgi?id=15579
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 54df209d2eed..e5ab41b559c0 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2534,6 +2534,17 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn) mb_debug(1, "gonna free %u blocks in group %u (0x%p):", entry->count, entry->group, entry); + if (test_opt(sb, DISCARD)) { + ext4_fsblk_t discard_block; + + discard_block = entry->start_blk + + ext4_group_first_block_no(sb, entry->group); + trace_ext4_discard_blocks(sb, + (unsigned long long)discard_block, + entry->count); + sb_issue_discard(sb, discard_block, entry->count); + } + err = ext4_mb_load_buddy(sb, entry->group, &e4b); /* we expect to find existing buddy because it's pinned */ BUG_ON(err != 0); @@ -2555,16 +2566,6 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn) page_cache_release(e4b.bd_bitmap_page); } ext4_unlock_group(sb, entry->group); - if (test_opt(sb, DISCARD)) { - ext4_fsblk_t discard_block; - - discard_block = entry->start_blk + - ext4_group_first_block_no(sb, entry->group); - trace_ext4_discard_blocks(sb, - (unsigned long long)discard_block, - entry->count); - sb_issue_discard(sb, discard_block, entry->count); - } kmem_cache_free(ext4_free_ext_cachep, entry); ext4_mb_release_desc(&e4b); } |