ceph: fix up error handling with snapdirs

There are several warts in the snapdir error handling. The -EOPNOTSUPP
return in __snapfh_to_dentry is currently lost, and the call to
ceph_handle_snapdir is not currently checked at all.

Fix all of this up and eliminate a BUG_ON in ceph_get_snapdir. We can
handle that case with a warning and return an error.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 13 insertions, 1 deletions

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 156f849f5385..5db7bf4c6a26 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -78,9 +78,21 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 	struct inode *inode = ceph_get_inode(parent->i_sb, vino);
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
-	BUG_ON(!S_ISDIR(parent->i_mode));
 	if (IS_ERR(inode))
 		return inode;
+
+	if (!S_ISDIR(parent->i_mode)) {
+		pr_warn_once("bad snapdir parent type (mode=0%o)\n",
+			     parent->i_mode);
+		return ERR_PTR(-ENOTDIR);
+	}
+
+	if (!(inode->i_state & I_NEW) && !S_ISDIR(inode->i_mode)) {
+		pr_warn_once("bad snapdir inode type (mode=0%o)\n",
+			     inode->i_mode);
+		return ERR_PTR(-ENOTDIR);
+	}
+
 	inode->i_mode = parent->i_mode;
 	inode->i_uid = parent->i_uid;
 	inode->i_gid = parent->i_gid;