From: Tao Ma Date: Mon, 28 May 2012 22:20:59 +0000 (-0400) Subject: ext4: protect group inode free counting with group lock X-Git-Tag: firefly_0821_release~3680^2~2694^2~8 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6f2e9f0e7d795214b9cf5a47724a273b705fd113;p=firefly-linux-kernel-4.4.55.git ext4: protect group inode free counting with group lock Now when we set the group inode free count, we don't have a proper group lock so that multiple threads may decrease the inode free count at the same time. And e2fsck will complain something like: Free inodes count wrong for group #1 (1, counted=0). Fix? no Free inodes count wrong for group #2 (3, counted=0). Fix? no Directories count wrong for group #2 (780, counted=779). Fix? no Free inodes count wrong for group #3 (2272, counted=2273). Fix? no So this patch try to protect it with the ext4_lock_group. btw, it is found by xfstests test case 269 and the volume is mkfsed with the parameter "-O ^resize_inode,^uninit_bg,extent,meta_bg,flex_bg,ext_attr" and I have run it 100 times and the error in e2fsck doesn't show up again. Signed-off-by: Tao Ma Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index ea32d7e1d6e3..03583ab52e0e 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -797,7 +797,10 @@ got: ext4_itable_unused_set(sb, gdp, (EXT4_INODES_PER_GROUP(sb) - ino)); up_read(&grp->alloc_sem); + } else { + ext4_lock_group(sb, group); } + ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1); if (S_ISDIR(mode)) { ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1); @@ -811,8 +814,8 @@ got: ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); ext4_group_desc_csum_set(sb, group, gdp); - ext4_unlock_group(sb, group); } + ext4_unlock_group(sb, group); BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);