Btrfs: set dead flag on the right root when destroying snapshot
We were setting the BTRFS_ROOT_SUBVOL_DEAD flag on the root of the
parent of our target snapshot, instead of setting it in the target
snapshot's root.
This is easy to observe by running the following scenario:
mkfs.btrfs -f /dev/sdd
mount /dev/sdd /mnt
btrfs subvolume create /mnt/first_subvol
btrfs subvolume snapshot -r /mnt /mnt/mysnap1
btrfs subvolume delete /mnt/first_subvol
btrfs subvolume snapshot -r /mnt /mnt/mysnap2
btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data
The send command failed because the send ioctl returned -EPERM.
A test case for xfstests follows.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 362720a..38f2169 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2312,16 +2312,16 @@
* again is not run concurrently.
*/
spin_lock(&dest->root_item_lock);
- root_flags = btrfs_root_flags(&root->root_item);
- if (root->send_in_progress == 0) {
- btrfs_set_root_flags(&root->root_item,
+ root_flags = btrfs_root_flags(&dest->root_item);
+ if (dest->send_in_progress == 0) {
+ btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
} else {
spin_unlock(&dest->root_item_lock);
btrfs_warn(root->fs_info,
"Attempt to delete subvolume %llu during send",
- root->root_key.objectid);
+ dest->root_key.objectid);
err = -EPERM;
goto out_dput;
}
@@ -2416,8 +2416,8 @@
out_unlock:
if (err) {
spin_lock(&dest->root_item_lock);
- root_flags = btrfs_root_flags(&root->root_item);
- btrfs_set_root_flags(&root->root_item,
+ root_flags = btrfs_root_flags(&dest->root_item);
+ btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
}