vfs: have chdir retry lookup and call once on ESTALE error

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

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/open.c b/fs/open.c
index a994ccf39b40..402dfcb6720b 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -394,8 +394,9 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
 {
         struct path path;
         int error;
-
-        error = user_path_dir(filename, &path);
+        unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+retry:
+        error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
         if (error)
                 goto out;
 
@@ -407,6 +408,10 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
 
 dput_and_out:
         path_put(&path);
+        if (retry_estale(error, lookup_flags)) {
+                lookup_flags |= LOOKUP_REVAL;
+                goto retry;
+        }
 out:
         return error;
 }