Merge patch series "vfs: preparatory changes to centralize locking of create/remove/rename"

NeilBrown <neilb@ownmail.net> says:

This is a re-re-revised selection of cleanups and API renaming which
continues my work to centralise locking of create/remove/rename
operations.

* patches from https://lore.kernel.org/20250922043121.193821-2-neilb@ownmail.net:
  debugfs: rename start_creating() to debugfs_start_creating()
  VFS: rename kern_path_locked() and related functions.
  VFS/audit: introduce kern_path_parent() for audit
  VFS: unify old_mnt_idmap and new_mnt_idmap in renamedata
  VFS: discard err2 in filename_create()
  VFS/ovl: add lookup_one_positive_killable()

Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

Documentation/filesystems/porting.rst

@@ -1285,3 +1285,15 @@ rather than a VMA, as the VMA at this stage is not yet valid.
 The vm_area_desc provides the minimum required information for a filesystem
 to initialise state upon memory mapping of a file-backed region, and output
 parameters for the file system to set this state.
+
+---
+
+**mandatory**
+
+Several functions are renamed:
+
+-  kern_path_locked -> start_removing_path
+-  kern_path_create -> start_creating_path
+-  user_path_create -> start_creating_user_path
+-  user_path_locked_at -> start_removing_user_path_at
+-  done_path_create -> end_creating_path

arch/powerpc/platforms/cell/spufs/syscalls.c

@@ -67,11 +67,11 @@ static long do_spu_create(const char __user *pathname, unsigned int flags,
 	struct dentry *dentry;
 	int ret;
 
-	dentry = user_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
+	dentry = start_creating_user_path(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
 	ret = PTR_ERR(dentry);
 	if (!IS_ERR(dentry)) {
 		ret = spufs_create(&path, dentry, flags, mode, neighbor);
-		done_path_create(&path, dentry);
+		end_creating_path(&path, dentry);
 	}
 
 	return ret;

drivers/base/devtmpfs.c

@@ -176,15 +176,15 @@ static int dev_mkdir(const char *name, umode_t mode)
 	struct dentry *dentry;
 	struct path path;
 
-	dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
+	dentry = start_creating_path(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
 	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
 	if (!IS_ERR(dentry))
 		/* mark as kernel-created inode */
 		d_inode(dentry)->i_private = &thread;
-	done_path_create(&path, dentry);
+	end_creating_path(&path, dentry);
 	return PTR_ERR_OR_ZERO(dentry);
 }
 
@@ -222,10 +222,10 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
 	struct path path;
 	int err;
 
-	dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
+	dentry = start_creating_path(AT_FDCWD, nodename, &path, 0);
 	if (dentry == ERR_PTR(-ENOENT)) {
 		create_path(nodename);
-		dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
+		dentry = start_creating_path(AT_FDCWD, nodename, &path, 0);
 	}
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
@@ -246,7 +246,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
 		/* mark as kernel-created inode */
 		d_inode(dentry)->i_private = &thread;
 	}
-	done_path_create(&path, dentry);
+	end_creating_path(&path, dentry);
 	return err;
 }
 
@@ -256,7 +256,7 @@ static int dev_rmdir(const char *name)
 	struct dentry *dentry;
 	int err;
 
-	dentry = kern_path_locked(name, &parent);
+	dentry = start_removing_path(name, &parent);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 	if (d_inode(dentry)->i_private == &thread)
@@ -265,9 +265,7 @@ static int dev_rmdir(const char *name)
 	else
 		err = -EPERM;
 
-	dput(dentry);
-	inode_unlock(d_inode(parent.dentry));
-	path_put(&parent);
+	end_removing_path(&parent, dentry);
 	return err;
 }
 
@@ -325,7 +323,7 @@ static int handle_remove(const char *nodename, struct device *dev)
 	int deleted = 0;
 	int err = 0;
 
-	dentry = kern_path_locked(nodename, &parent);
+	dentry = start_removing_path(nodename, &parent);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
@@ -349,10 +347,8 @@ static int handle_remove(const char *nodename, struct device *dev)
 		if (!err || err == -ENOENT)
 			deleted = 1;
 	}
-	dput(dentry);
-	inode_unlock(d_inode(parent.dentry));
+	end_removing_path(&parent, dentry);
 
-	path_put(&parent);
 	if (deleted && strchr(nodename, '/'))
 		delete_path(nodename);
 	return err;

fs/bcachefs/fs-ioctl.c

@@ -255,7 +255,7 @@ static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 		snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
 	}
 
-	dst_dentry = user_path_create(arg.dirfd,
+	dst_dentry = start_creating_user_path(arg.dirfd,
 			(const char __user *)(unsigned long)arg.dst_ptr,
 			&dst_path, lookup_flags);
 	error = PTR_ERR_OR_ZERO(dst_dentry);
@@ -314,7 +314,7 @@ static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 	d_instantiate(dst_dentry, &inode->v);
 	fsnotify_mkdir(dir, dst_dentry);
 err3:
-	done_path_create(&dst_path, dst_dentry);
+	end_creating_path(&dst_path, dst_dentry);
 err2:
 	if (arg.src_ptr)
 		path_put(&src_path);
@@ -334,7 +334,7 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
 	if (arg.flags)
 		return -EINVAL;
 
-	victim = user_path_locked_at(arg.dirfd, name, &path);
+	victim = start_removing_user_path_at(arg.dirfd, name, &path);
 	if (IS_ERR(victim))
 		return PTR_ERR(victim);
 
@@ -351,9 +351,7 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
 		d_invalidate(victim);
 	}
 err:
-	inode_unlock(dir);
-	dput(victim);
-	path_put(&path);
+	end_removing_path(&path, victim);
 	return ret;
 }
 

fs/cachefiles/namei.c

@@ -387,10 +387,9 @@ int cachefiles_bury_object(struct cachefiles_cache *cache,
 		cachefiles_io_error(cache, "Rename security error %d", ret);
 	} else {
 		struct renamedata rd = {
-			.old_mnt_idmap	= &nop_mnt_idmap,
+			.mnt_idmap	= &nop_mnt_idmap,
 			.old_parent	= dir,
 			.old_dentry	= rep,
-			.new_mnt_idmap	= &nop_mnt_idmap,
 			.new_parent	= cache->graveyard,
 			.new_dentry	= grave,
 		};

fs/debugfs/inode.c

@@ -353,7 +353,8 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
 }
 EXPORT_SYMBOL_GPL(debugfs_lookup);
 
-static struct dentry *start_creating(const char *name, struct dentry *parent)
+static struct dentry *debugfs_start_creating(const char *name,
+					     struct dentry *parent)
 {
 	struct dentry *dentry;
 	int error;
@@ -419,7 +420,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
 	if (!(mode & S_IFMT))
 		mode |= S_IFREG;
 	BUG_ON(!S_ISREG(mode));
-	dentry = start_creating(name, parent);
+	dentry = debugfs_start_creating(name, parent);
 
 	if (IS_ERR(dentry))
 		return dentry;
@@ -568,7 +569,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_size);
  */
 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 {
-	struct dentry *dentry = start_creating(name, parent);
+	struct dentry *dentry = debugfs_start_creating(name, parent);
 	struct inode *inode;
 
 	if (IS_ERR(dentry))
@@ -615,7 +616,7 @@ struct dentry *debugfs_create_automount(const char *name,
 					debugfs_automount_t f,
 					void *data)
 {
-	struct dentry *dentry = start_creating(name, parent);
+	struct dentry *dentry = debugfs_start_creating(name, parent);
 	struct inode *inode;
 
 	if (IS_ERR(dentry))
@@ -678,7 +679,7 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
 	if (!link)
 		return ERR_PTR(-ENOMEM);
 
-	dentry = start_creating(name, parent);
+	dentry = debugfs_start_creating(name, parent);
 	if (IS_ERR(dentry)) {
 		kfree(link);
 		return dentry;

fs/ecryptfs/inode.c

@@ -634,10 +634,9 @@ ecryptfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		goto out_lock;
 	}
 
-	rd.old_mnt_idmap	= &nop_mnt_idmap;
+	rd.mnt_idmap		= &nop_mnt_idmap;
 	rd.old_parent		= lower_old_dir_dentry;
 	rd.old_dentry		= lower_old_dentry;
-	rd.new_mnt_idmap	= &nop_mnt_idmap;
 	rd.new_parent		= lower_new_dir_dentry;
 	rd.new_dentry		= lower_new_dentry;
 	rc = vfs_rename(&rd);

fs/init.c

@@ -149,7 +149,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
 	else if (!(S_ISBLK(mode) || S_ISCHR(mode)))
 		return -EINVAL;
 
-	dentry = kern_path_create(AT_FDCWD, filename, &path, 0);
+	dentry = start_creating_path(AT_FDCWD, filename, &path, 0);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
@@ -158,7 +158,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
 	if (!error)
 		error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
 				  dentry, mode, new_decode_dev(dev));
-	done_path_create(&path, dentry);
+	end_creating_path(&path, dentry);
 	return error;
 }
 
@@ -173,7 +173,7 @@ int __init init_link(const char *oldname, const char *newname)
 	if (error)
 		return error;
 
-	new_dentry = kern_path_create(AT_FDCWD, newname, &new_path, 0);
+	new_dentry = start_creating_path(AT_FDCWD, newname, &new_path, 0);
 	error = PTR_ERR(new_dentry);
 	if (IS_ERR(new_dentry))
 		goto out;
@@ -191,7 +191,7 @@ int __init init_link(const char *oldname, const char *newname)
 	error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
 			 new_dentry, NULL);
 out_dput:
-	done_path_create(&new_path, new_dentry);
+	end_creating_path(&new_path, new_dentry);
 out:
 	path_put(&old_path);
 	return error;
@@ -203,14 +203,14 @@ int __init init_symlink(const char *oldname, const char *newname)
 	struct path path;
 	int error;
 
-	dentry = kern_path_create(AT_FDCWD, newname, &path, 0);
+	dentry = start_creating_path(AT_FDCWD, newname, &path, 0);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 	error = security_path_symlink(&path, dentry, oldname);
 	if (!error)
 		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
 				    dentry, oldname);
-	done_path_create(&path, dentry);
+	end_creating_path(&path, dentry);
 	return error;
 }
 
@@ -225,7 +225,8 @@ int __init init_mkdir(const char *pathname, umode_t mode)
 	struct path path;
 	int error;
 
-	dentry = kern_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
+	dentry = start_creating_path(AT_FDCWD, pathname, &path,
+				     LOOKUP_DIRECTORY);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 	mode = mode_strip_umask(d_inode(path.dentry), mode);
@@ -236,7 +237,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
 		if (IS_ERR(dentry))
 			error = PTR_ERR(dentry);
 	}
-	done_path_create(&path, dentry);
+	end_creating_path(&path, dentry);
 	return error;
 }