ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc From: Akira Fujita <a-fujita@xxxxxxxxxxxxx> If block allocation failed after marking claimed blocks as dirty blocks with nodelalloc, we have to subtract these blocks from s_dirty_blocks_counter in error handling. Otherwise s_dirty_blocks_counter goes wrong so that filesystem's free blocks decreases incorrectly. This issue was reported as ext4 online defrag's bug by Li Zefan. http://marc.info/?l=linux-ext4&m=122697235715170&w=2 Reported-by: Li Zefan <lizf@xxxxxxxxxxxxxx> Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxxx> --- mballoc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff -X linux-2.6.28-rc6-ext4/Documentation/dontdiff -upNr linux-2.6.28-rc6-ext4/fs/ext4/mballoc.c linux-2.6.28-rc6-mballoc-fix/fs/ext4/mballoc.c --- linux-2.6.28-rc6-ext4/fs/ext4/mballoc.c 2008-12-01 11:44:28.000000000 +0900 +++ linux-2.6.28-rc6-mballoc-fix/fs/ext4/mballoc.c 2008-12-01 12:04:06.000000000 +0900 @@ -4495,12 +4495,18 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t if (!ac) { ar->len = 0; *errp = -ENOMEM; + if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) + percpu_counter_sub(&sbi->s_dirtyblocks_counter, + reserv_blks); goto out1; } *errp = ext4_mb_initialize_context(ac, ar); if (*errp) { ar->len = 0; + if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) + percpu_counter_sub(&sbi->s_dirtyblocks_counter, + reserv_blks); goto out2; } @@ -4541,6 +4547,9 @@ repeat: if (freed) goto repeat; *errp = -ENOSPC; + if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) + percpu_counter_sub(&sbi->s_dirtyblocks_counter, + reserv_blks); ac->ac_b_ex.fe_len = 0; ar->len = 0; ext4_mb_show_ac(ac); -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
