Btrfs: send, add missing check for dead clone root

After we locked the root's root item, a concurrent snapshot deletion
call might have set the dead flag on it. So check if the dead flag
is set and abort if it is, just like we do for the parent root.

Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: Chris Mason <[email protected]>

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index d6033f540cc75cfb49ddbe5f07689d67fdefc492..6ec28f13659eb5d99f80413943fcf197b9bfebcb 100644 (file)
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -5855,7 +5855,8 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
                        clone_sources_to_rollback = i + 1;
                        spin_lock(&clone_root->root_item_lock);
                        clone_root->send_in_progress++;
-                       if (!btrfs_root_readonly(clone_root)) {
+                       if (!btrfs_root_readonly(clone_root) ||
+                           btrfs_root_dead(clone_root)) {
                                spin_unlock(&clone_root->root_item_lock);
                                srcu_read_unlock(&fs_info->subvol_srcu, index);
                                ret = -EPERM;