Btrfs: Fix subvolume creation locking rules

Creating a subvolume is in many ways like a normal VFS ->mkdir, and we
really need to play with the VFS topology locking rules.  So instead of
just creating the snapshot on disk and then later getting rid of
confliting aliases do it correctly from the start.  This will become
especially important once we allow for subvolumes anywhere in the tree,
and not just below a hidden root.

Note that snapshots will need the same treatment, but do to the delay
in creating them we can't do it currently.  Chris promised to fix that
issue, so I'll wait on that.

Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3fa9b8d6751..8559f39fd47 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1791,7 +1791,7 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root);
 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
 int btrfs_writepages(struct address_space *mapping,
 		     struct writeback_control *wbc);
-int btrfs_create_subvol_root(struct btrfs_root *new_root,
+int btrfs_create_subvol_root(struct btrfs_root *new_root, struct dentry *dentry,
 		struct btrfs_trans_handle *trans, u64 new_dirid,
 		struct btrfs_block_group_cache *block_group);