From 3db674a0363cd29feae5ca995f55030707f04ede Mon Sep 17 00:00:00 2001 From: johnny1_lin Date: Tue, 15 Jan 2013 10:14:01 +0800 Subject: [PATCH] ext4: protect group inode free counting with group lock Patch from Ken that can solve fsstress failing issue commit b9fa7bb8ff207eeb27d2e0ed45b8c3acf1a7af8c Author: Tao Ma Date: Mon May 28 18:20:59 2012 -0400 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. Change-Id: Iba773843728759e1d64d4ff57765288eb5977665 Reviewed-on: http://mcrd1-5.corpnet.asus/code-review/master/67871 Reviewed-by: Lin Johnny1 Tested-by: Lin Johnny1 Reviewed-by: Sam hblee --- fs/ext4/ialloc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 409c2ee7750..cb90020459f 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -772,7 +772,10 @@ 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); @@ -784,8 +787,8 @@ got: } if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { gdp->bg_checksum = ext4_group_desc_csum(sbi, 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);