vfs: fix readlinkat to retry on ESTALE

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

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/stat.c b/fs/stat.c
index d22199527880..14f45459c83d 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -300,11 +300,13 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
         struct path path;
         int error;
         int empty = 0;
+        unsigned int lookup_flags = LOOKUP_EMPTY;
 
         if (bufsiz <= 0)
                 return -EINVAL;
 
-        error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty);
+retry:
+        error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
         if (!error) {
                 struct inode *inode = path.dentry->d_inode;
 
@@ -318,6 +320,10 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
                         }
                 }
                 path_put(&path);
+                if (retry_estale(error, lookup_flags)) {
+                        lookup_flags |= LOOKUP_REVAL;
+                        goto retry;
+                }
         }
         return error;
 }