[PATCH 10/14] namei: clean up do_symlinkat retry logic

[Dmitry Kadashev <dkadashev@gmail.com>]

No functional changes, just move the main logic to a helper function to
make the whole thing easier to follow.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/CAHk-=wiG+sN+2zSoAOggKCGue2kOJvw3rQySvQXsZstRQFTN+g@mail.gmail.com/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/namei.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index c4d75c94adce..61cf6bbe1e5c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4234,22 +4234,18 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 }
 EXPORT_SYMBOL(vfs_symlink);
 
-int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
+static int try_symlinkat(struct filename *from, int newdfd, struct filename *to,
+			 unsigned int lookup_flags)
 {
 	int error;
 	struct dentry *dentry;
 	struct path path;
-	unsigned int lookup_flags = 0;
 
-retry:
-	if (IS_ERR(from)) {
-		error = PTR_ERR(from);
-		goto out;
-	}
+	if (IS_ERR(from))
+		return PTR_ERR(from);
 	dentry = __filename_create(newdfd, to, &path, lookup_flags);
-	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
-		goto out;
+		return PTR_ERR(dentry);
 
 	error = security_path_symlink(&path, dentry, from->name);
 	if (!error) {
@@ -4260,11 +4256,17 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
 				    from->name);
 	}
 	done_path_create(&path, dentry);
-out:
-	if (unlikely(retry_estale(error, lookup_flags))) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
+	return error;
+}
+
+int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
+{
+	int error;
+
+	error = try_symlinkat(from, newdfd, to, 0);
+	if (unlikely(retry_estale(error, 0)))
+		error = try_symlinkat(from, newdfd, to, LOOKUP_REVAL);
+
 	putname(to);
 	putname(from);
 	return error;
-- 
2.30.2