linux-kernel - [PATCH 05/13] selinux: Use simple_start_creating() / simple_done

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Message-ID: <20260204050726.177283-6-neilb@ownmail.net>
Date: Wed,  4 Feb 2026 15:57:49 +1100
From: NeilBrown <neilb@...mail.net>
To: Christian Brauner <brauner@...nel.org>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	David Howells <dhowells@...hat.com>,
	Jan Kara <jack@...e.cz>,
	Chuck Lever <chuck.lever@...cle.com>,
	Jeff Layton <jlayton@...nel.org>,
	Miklos Szeredi <miklos@...redi.hu>,
	Amir Goldstein <amir73il@...il.com>,
	John Johansen <john.johansen@...onical.com>,
	Paul Moore <paul@...l-moore.com>,
	James Morris <jmorris@...ei.org>,
	"Serge E. Hallyn" <serge@...lyn.com>,
	Stephen Smalley <stephen.smalley.work@...il.com>
Cc: linux-kernel@...r.kernel.org,
	netfs@...ts.linux.dev,
	linux-fsdevel@...r.kernel.org,
	linux-nfs@...r.kernel.org,
	linux-unionfs@...r.kernel.org,
	apparmor@...ts.ubuntu.com,
	linux-security-module@...r.kernel.org,
	selinux@...r.kernel.org
Subject: [PATCH 05/13] selinux: Use simple_start_creating() / simple_done_creating()

From: NeilBrown <neil@...wn.name>

Instead of explicitly locking the parent and performing a lookup in
selinux, use simple_start_creating(), and then use
simple_done_creating() to unlock.

This extends the region that the directory is locked for, and also
performs a lookup.
The lock extension is of no real consequence.
The lookup uses simple_lookup() and so always succeeds.  Thus when
d_make_persistent() is called the dentry will already be hashed.
d_make_persistent() handles this case.

Signed-off-by: NeilBrown <neil@...wn.name>
---
 security/selinux/selinuxfs.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 896acad1f5f7..97e02cd5a9dc 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1930,15 +1930,16 @@ static const struct inode_operations swapover_dir_inode_operations = {
 static struct dentry *sel_make_swapover_dir(struct super_block *sb,
 						unsigned long *ino)
 {
-	struct dentry *dentry = d_alloc_name(sb->s_root, ".swapover");
+	struct dentry *dentry;
 	struct inode *inode;
 
-	if (!dentry)
+	inode = sel_make_inode(sb, S_IFDIR);
+	if (!inode)
 		return ERR_PTR(-ENOMEM);
 
-	inode = sel_make_inode(sb, S_IFDIR);
-	if (!inode) {
-		dput(dentry);
+	dentry = simple_start_creating(sb->s_root, ".swapover");
+	if (!dentry) {
+		iput(inode);
 		return ERR_PTR(-ENOMEM);
 	}
 
@@ -1946,11 +1947,9 @@ static struct dentry *sel_make_swapover_dir(struct super_block *sb,
 	inode->i_ino = ++(*ino);
 	/* directory inodes start off with i_nlink == 2 (for "." entry) */
 	inc_nlink(inode);
-	inode_lock(sb->s_root->d_inode);
 	d_make_persistent(dentry, inode);
 	inc_nlink(sb->s_root->d_inode);
-	inode_unlock(sb->s_root->d_inode);
-	dput(dentry);
+	simple_done_creating(dentry);
 	return dentry;	// borrowed
 }
 
-- 
2.50.0.107.gf914562f5916.dirty