9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"

In v9fs_vfs_rename() we need to clone the parents' fids, not just
find them.

Spotted-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 6 insertions, 2 deletions

diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index 12700df0bb51..d4c5002d56ad 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -31,4 +31,8 @@ static inline struct p9_fid *v9fs_parent_fid(struct dentry *dentry)
 struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
 void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
+static inline struct p9_fid *clone_fid(struct p9_fid *fid)
+{
+        return IS_ERR(fid) ? fid :  p9_client_walk(fid, 0, NULL, 1);
+}
 #endif
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 7da9a8354fad..26189eebcd1c 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -975,13 +975,13 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         if (IS_ERR(oldfid))
                 return PTR_ERR(oldfid);
 
-        olddirfid = v9fs_parent_fid(old_dentry);
+        olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
         if (IS_ERR(olddirfid)) {
                 retval = PTR_ERR(olddirfid);
                 goto done;
         }
 
-        newdirfid = v9fs_parent_fid(new_dentry);
+        newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
         if (IS_ERR(newdirfid)) {
                 retval = PTR_ERR(newdirfid);
                 goto clunk_olddir;