[PATCH v9 07/34] vfs: fix symlinkat to retry on ESTALE errors

[Jeff Layton <jlayton@redhat.com>]

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/namei.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 04e4851..af1b473 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3525,21 +3525,25 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
 	struct filename *from;
 	struct dentry *dentry;
 	struct path path;
+	unsigned int try = 0;
 
 	from = getname(oldname);
 	if (IS_ERR(from))
 		return PTR_ERR(from);
 
-	dentry = user_path_create(newdfd, newname, &path, false, false);
-	error = PTR_ERR(dentry);
-	if (IS_ERR(dentry))
-		goto out_putname;
+	do {
+		dentry = user_path_create(newdfd, newname, &path, false, try);
+		if (IS_ERR(dentry)) {
+			error = PTR_ERR(dentry);
+			break;
+		}
 
-	error = security_path_symlink(&path, dentry, from->name);
-	if (!error)
-		error = vfs_symlink(path.dentry->d_inode, dentry, from->name);
-	done_path_create(&path, dentry);
-out_putname:
+		error = security_path_symlink(&path, dentry, from->name);
+		if (!error)
+			error = vfs_symlink(path.dentry->d_inode, dentry,
+						from->name);
+		done_path_create(&path, dentry);
+	} while (retry_estale(error, try++));
 	putname(from);
 	return error;
 }
-- 
1.7.11.7