prepend_path() needs to reinitialize dentry/vfsmount/mnt on restarts

... and equivalent is needed in 3.12; it's broken there as well

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

1 files changed, 6 insertions, 3 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index eacc853a2e3a..a9dd384c5e80 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2912,9 +2912,9 @@ static int prepend_path(const struct path *path,
                         const struct path *root,
                         char **buffer, int *buflen)
 {
-        struct dentry *dentry = path->dentry;
-        struct vfsmount *vfsmnt = path->mnt;
-        struct mount *mnt = real_mount(vfsmnt);
+        struct dentry *dentry;
+        struct vfsmount *vfsmnt;
+        struct mount *mnt;
         int error = 0;
         unsigned seq, m_seq = 0;
         char *bptr;
@@ -2929,6 +2929,9 @@ restart:
         bptr = *buffer;
         blen = *buflen;
         error = 0;
+        dentry = path->dentry;
+        vfsmnt = path->mnt;
+        mnt = real_mount(vfsmnt);
         read_seqbegin_or_lock(&rename_lock, &seq);
         while (dentry != root->dentry || vfsmnt != root->mnt) {
                 struct dentry * parent;