Btrfs: fix error handling in btrfs_get_sb

If we failed to find the root subvol id, or the subvol=<name>, we would
deactivate the locked super and close the devices.  The problem is at this point
we have gotten the SB all setup, which includes setting super_operations, so
when we'd deactiveate the super, we'd do a close_ctree() which closes the
devices, so we'd end up closing the devices twice.  So if you do something like
this

mount /dev/sda1 /mnt/test1
mount /dev/sda1 /mnt/test2 -o subvol=xxx
umount /mnt/test1

it would blow up (if subvol xxx doesn't exist).  This patch fixes that problem.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index afab6ca14d03..d1867cda92a7 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -629,7 +629,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
         if (IS_ERR(root)) {
                 error = PTR_ERR(root);
                 deactivate_locked_super(s);
-                goto error;
+                goto error_free_subvol_name;
         }
         /* if they gave us a subvolume name bind mount into that */
         if (strcmp(subvol_name, ".")) {
@@ -643,14 +643,14 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                         deactivate_locked_super(s);
                         error = PTR_ERR(new_root);
                         dput(root);
-                        goto error_close_devices;
+                        goto error_free_subvol_name;
                 }
                 if (!new_root->d_inode) {
                         dput(root);
                         dput(new_root);
                         deactivate_locked_super(s);
                         error = -ENXIO;
-                        goto error_close_devices;
+                        goto error_free_subvol_name;
                 }
                 dput(root);
                 root = new_root;
@@ -668,7 +668,6 @@ error_close_devices:
         btrfs_close_devices(fs_devices);
 error_free_subvol_name:
         kfree(subvol_name);
-error:
         return error;
 }