Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6f2e9f0e authored by Tao Ma's avatar Tao Ma Committed by Theodore Ts'o
Browse files

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: default avatarTao Ma <boyu.mt@taobao.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 8563000d

fs/ext4/ialloc.c

+4 −1
Original line number Original line Diff line number Diff line
@@ -797,7 +797,10 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode, 
			ext4_itable_unused_set(sb, gdp,

			ext4_itable_unused_set(sb, gdp,

					(EXT4_INODES_PER_GROUP(sb) - ino));

					(EXT4_INODES_PER_GROUP(sb) - ino));

		up_read(&grp->alloc_sem);

		up_read(&grp->alloc_sem);

	} else {

		ext4_lock_group(sb, group);

	}

	}



	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);

	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);

	if (S_ISDIR(mode)) {

	if (S_ISDIR(mode)) {

		ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);

		ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
@@ -811,8 +814,8 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode, 
		ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,

		ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,

					   EXT4_INODES_PER_GROUP(sb) / 8);

					   EXT4_INODES_PER_GROUP(sb) / 8);

		ext4_group_desc_csum_set(sb, group, gdp);

		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");

	BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");

	err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);

	err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);