[PATCH v7 37/49] vfs: make fchmodat retry once on ESTALE errors

[Jeff Layton]

Signed-off-by: Jeff Layton <jlayton at redhat.com>
---
 fs/open.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index a015cb8..232cbfb 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -506,12 +506,17 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode
 {
 	struct path path;
 	int error;
+	unsigned int try = 0;
+	int lookup_flags = LOOKUP_FOLLOW;
 
-	error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
-	if (!error) {
+	do {
+		error = user_path_at(dfd, filename, lookup_flags, &path);
+		if (error)
+			break;
 		error = chmod_common(&path, mode);
 		path_put(&path);
-	}
+		lookup_flags |= LOOKUP_REVAL;
+	} while (retry_estale(error, try++));
 	return error;
 }
 
-- 
1.7.11.4