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authorTao Ma <boyu.mt@taobao.com>2012-05-29 00:20:59 +0200
committerTheodore Ts'o <tytso@mit.edu>2012-05-29 00:20:59 +0200
commit6f2e9f0e7d795214b9cf5a47724a273b705fd113 (patch)
treec33979cd8d907b0eab9e3d9eada09a09e222e54a /fs/ext4
parentext4: use consistent ssize_t type in ext4_file_write() (diff)
downloadlinux-6f2e9f0e7d795214b9cf5a47724a273b705fd113.tar.xz
linux-6f2e9f0e7d795214b9cf5a47724a273b705fd113.zip
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 <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/ialloc.c5
1 files changed, 4 insertions, 1 deletions
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);