[PATCH 06/14] namei: clean up do_mkdirat 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-=wijsw1QSsQHFu_6dEoZEr_zvT7++WJWohcuEkLqqXBGrQ@mail.gmail.com/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/namei.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 54dbd1e38298..50ab1cd00983 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3850,18 +3850,16 @@ int vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 }
 EXPORT_SYMBOL(vfs_mkdir);
 
-int do_mkdirat(int dfd, struct filename *name, umode_t mode)
+static int try_mkdirat(int dfd, struct filename *name, umode_t mode,
+		       unsigned int lookup_flags)
 {
 	struct dentry *dentry;
 	struct path path;
 	int error;
-	unsigned int lookup_flags = LOOKUP_DIRECTORY;
 
-retry:
 	dentry = __filename_create(dfd, name, &path, lookup_flags);
-	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
-		goto out;
+		return PTR_ERR(dentry);
 
 	if (!IS_POSIXACL(path.dentry->d_inode))
 		mode &= ~current_umask();
@@ -3873,11 +3871,18 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
 				  mode);
 	}
 	done_path_create(&path, dentry);
-out:
-	if (unlikely(retry_estale(error, lookup_flags))) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
+
+	return error;
+}
+
+int do_mkdirat(int dfd, struct filename *name, umode_t mode)
+{
+	int error;
+
+	error = try_mkdirat(dfd, name, mode, 0);
+	if (unlikely(retry_estale(error, 0)))
+		error = try_mkdirat(dfd, name, mode, LOOKUP_REVAL);
+
 	putname(name);
 	return error;
 }
-- 
2.30.2