From: Guangyu Sun Date: Mon, 16 Sep 2013 17:42:03 +0000 (-0700) Subject: Btrfs: dir_inode_operations should use btrfs_update_time also X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=93fd63c2f001ca6797c6b15b696a484b165b4800;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git Btrfs: dir_inode_operations should use btrfs_update_time also Commit 2bc5565286121d2a77ccd728eb3484dff2035b58 (Btrfs: don't update atime on RO subvolumes) ensures that the access time of an inode is not updated when the inode lives in a read-only subvolume. However, if a directory on a read-only subvolume is accessed, the atime is updated. This results in a write operation to a read-only subvolume. I believe that access times should never be updated on read-only subvolumes. To reproduce: # mkfs.btrfs -f /dev/dm-3 (...) # mount /dev/dm-3 /mnt # btrfs subvol create /mnt/sub Create subvolume '/mnt/sub' # mkdir /mnt/sub/dir # echo "abc" > /mnt/sub/dir/file # btrfs subvol snapshot -r /mnt/sub /mnt/rosnap Create a readonly snapshot of '/mnt/sub' in '/mnt/rosnap' # stat /mnt/rosnap/dir File: `/mnt/rosnap/dir' Size: 8 Blocks: 0 IO Block: 4096 directory Device: 16h/22d Inode: 257 Links: 1 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-09-11 07:21:49.389157126 -0400 Modify: 2013-09-11 07:22:02.330156079 -0400 Change: 2013-09-11 07:22:02.330156079 -0400 # ls /mnt/rosnap/dir file # stat /mnt/rosnap/dir File: `/mnt/rosnap/dir' Size: 8 Blocks: 0 IO Block: 4096 directory Device: 16h/22d Inode: 257 Links: 1 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-09-11 07:22:56.797151670 -0400 Modify: 2013-09-11 07:22:02.330156079 -0400 Change: 2013-09-11 07:22:02.330156079 -0400 Reported-by: Koen De Wit Signed-off-by: Guangyu Sun Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 931036c6eb90..8af6c03953ad 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8617,11 +8617,13 @@ static const struct inode_operations btrfs_dir_inode_operations = { .removexattr = btrfs_removexattr, .permission = btrfs_permission, .get_acl = btrfs_get_acl, + .update_time = btrfs_update_time, }; static const struct inode_operations btrfs_dir_ro_inode_operations = { .lookup = btrfs_lookup, .permission = btrfs_permission, .get_acl = btrfs_get_acl, + .update_time = btrfs_update_time, }; static const struct file_operations btrfs_dir_file_operations = {