linux-kernel - [PATCH v2 1/7] apparmor: just use vfs_kern

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Message-Id: <20200421135119.30007-2-eesposit@redhat.com>
Date:   Tue, 21 Apr 2020 15:51:13 +0200
From:   Emanuele Giuseppe Esposito <eesposit@...hat.com>
To:     linux-fsdevel@...r.kernel.org
Cc:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Frederic Barrat <fbarrat@...ux.ibm.com>,
        Andrew Donnellan <ajd@...ux.ibm.com>,
        Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Manoj N. Kumar" <manoj@...ux.ibm.com>,
        "Matthew R. Ochs" <mrochs@...ux.ibm.com>,
        Uma Krishnan <ukrishn@...ux.ibm.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Joel Becker <jlbec@...lplan.org>,
        Christoph Hellwig <hch@....de>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        John Johansen <john.johansen@...onical.com>,
        James Morris <jmorris@...ei.org>,
        "Serge E. Hallyn" <serge@...lyn.com>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, linux-scsi@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Emanuele Giuseppe Esposito <eesposit@...hat.com>
Subject: [PATCH v2 1/7] apparmor: just use vfs_kern_mount to make .null

aa_mk_null_file is using simple_pin_fs/simple_release_fs with local
variables as arguments, for what would amount to a simple
vfs_kern_mount/mntput pair if everything was inlined.  Just use
the normal filesystem API since the reference counting is not needed
here (it is a local variable and always 0 on entry and on exit).

There is no functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@...hat.com>
---
 security/apparmor/apparmorfs.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 280741fc0f5f..36f848734902 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -2525,14 +2525,15 @@ struct path aa_null;
 
 static int aa_mk_null_file(struct dentry *parent)
 {
-	struct vfsmount *mount = NULL;
+	struct file_system_type *type = parent->d_sb->s_type;
+	struct vfsmount *mount;
 	struct dentry *dentry;
 	struct inode *inode;
-	int count = 0;
-	int error = simple_pin_fs(parent->d_sb->s_type, &mount, &count);
+	int error;
 
-	if (error)
-		return error;
+	mount = vfs_kern_mount(type, SB_KERNMOUNT, type->name, NULL);
+	if (IS_ERR(mount))
+		return PTR_ERR(mount);
 
 	inode_lock(d_inode(parent));
 	dentry = lookup_one_len(NULL_FILE_NAME, parent, strlen(NULL_FILE_NAME));
@@ -2561,7 +2562,7 @@ static int aa_mk_null_file(struct dentry *parent)
 	dput(dentry);
 out:
 	inode_unlock(d_inode(parent));
-	simple_release_fs(&mount, &count);
+	mntput(mount);
 	return error;
 }
 
-- 
2.25.2