vfs: fix renameat to retry on ESTALE errors
...as always, rename is the messiest of the bunch. We have to track
whether to retry or not via a separate flag since the error handling
is already quite complex.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 8a262c2..43a97ee 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3840,15 +3840,17 @@
struct nameidata oldnd, newnd;
struct filename *from;
struct filename *to;
+ unsigned int lookup_flags = 0;
+ bool should_retry = false;
int error;
-
- from = user_path_parent(olddfd, oldname, &oldnd, 0);
+retry:
+ from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
error = PTR_ERR(from);
goto exit;
}
- to = user_path_parent(newdfd, newname, &newnd, 0);
+ to = user_path_parent(newdfd, newname, &newnd, lookup_flags);
if (IS_ERR(to)) {
error = PTR_ERR(to);
goto exit1;
@@ -3920,11 +3922,18 @@
unlock_rename(new_dir, old_dir);
mnt_drop_write(oldnd.path.mnt);
exit2:
+ if (retry_estale(error, lookup_flags))
+ should_retry = true;
path_put(&newnd.path);
putname(to);
exit1:
path_put(&oldnd.path);
putname(from);
+ if (should_retry) {
+ should_retry = false;
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
exit:
return error;
}