From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 3 Aug 2016 15:02:48 +0000 (-0400)
Subject: 9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
X-Git-Tag: v4.8-rc1~6^2~3
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=797fc16d8f00bf681b7f9969c0701725b472b11a

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>
---

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;