[PATCH v1 RESEND 11/12] vfs: fix linkat to retry on ESTALE errors

[Jeff Layton <jlayton@redhat.com>]

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/namei.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index b5d28fe..a40dcbb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3054,6 +3054,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
 	struct path old_path, new_path;
 	int how = 0;
 	int error;
+	unsigned int try = 0;
 
 	if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0)
 		return -EINVAL;
@@ -3071,11 +3072,12 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
 	if (flags & AT_SYMLINK_FOLLOW)
 		how |= LOOKUP_FOLLOW;
 
+retry:
 	error = user_path_at(olddfd, oldname, how, &old_path);
 	if (error)
 		return error;
 
-	new_dentry = user_path_create(newdfd, newname, &new_path, false, false);
+	new_dentry = user_path_create(newdfd, newname, &new_path, false, try);
 	error = PTR_ERR(new_dentry);
 	if (IS_ERR(new_dentry))
 		goto out;
@@ -3098,7 +3100,10 @@ out_dput:
 	path_put(&new_path);
 out:
 	path_put(&old_path);
-
+	if (retry_estale(error, try++)) {
+		how |= LOOKUP_REVAL;
+		goto retry;
+	}
 	return error;
 }
 
-- 
1.7.7.6