[PATCH 1/7] namei: clean up do_rmdir retry logic

[Dmitry Kadashev <dkadashev@gmail.com>]

Moving the main logic to a helper function makes the whole thing much
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-=wh=cpt_tQCirzFZRPawRpbuFTZ2MxNpXiyUF+eBXF=+sw@mail.gmail.com/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/namei.c | 44 +++++++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index b5adfd4f7de6..ae6cde7dc91e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3947,7 +3947,8 @@ int vfs_rmdir(struct user_namespace *mnt_userns, struct inode *dir,
 }
 EXPORT_SYMBOL(vfs_rmdir);
 
-int do_rmdir(int dfd, struct filename *name)
+static int rmdir_helper(int dfd, struct filename *name,
+			unsigned int lookup_flags)
 {
 	struct user_namespace *mnt_userns;
 	int error;
@@ -3955,54 +3956,59 @@ int do_rmdir(int dfd, struct filename *name)
 	struct path path;
 	struct qstr last;
 	int type;
-	unsigned int lookup_flags = 0;
-retry:
+
 	error = __filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
 	if (error)
-		goto exit1;
+		return error;
 
 	switch (type) {
 	case LAST_DOTDOT:
 		error = -ENOTEMPTY;
-		goto exit2;
+		goto exit1;
 	case LAST_DOT:
 		error = -EINVAL;
-		goto exit2;
+		goto exit1;
 	case LAST_ROOT:
 		error = -EBUSY;
-		goto exit2;
+		goto exit1;
 	}
 
 	error = mnt_want_write(path.mnt);
 	if (error)
-		goto exit2;
+		goto exit1;
 
 	inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
 	dentry = __lookup_hash(&last, path.dentry, lookup_flags);
 	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
-		goto exit3;
+		goto exit2;
 	if (!dentry->d_inode) {
 		error = -ENOENT;
-		goto exit4;
+		goto exit3;
 	}
 	error = security_path_rmdir(&path, dentry);
 	if (error)
-		goto exit4;
+		goto exit3;
 	mnt_userns = mnt_user_ns(path.mnt);
 	error = vfs_rmdir(mnt_userns, path.dentry->d_inode, dentry);
-exit4:
-	dput(dentry);
 exit3:
+	dput(dentry);
+exit2:
 	inode_unlock(path.dentry->d_inode);
 	mnt_drop_write(path.mnt);
-exit2:
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
 exit1:
+	path_put(&path);
+	return error;
+}
+
+int do_rmdir(int dfd, struct filename *name)
+{
+	int error;
+
+	error = rmdir_helper(dfd, name, 0);
+	if (retry_estale(error, 0))
+		error = rmdir_helper(dfd, name, LOOKUP_REVAL);
+
 	putname(name);
 	return error;
 }
-- 
2.30.2