[PATCH v2 1/7] apparmor: just use vfs_kern_mount to make .null

From: Emanuele Giuseppe Esposito
Date: Tue Apr 21 2020 - 09:52:26 EST


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@xxxxxxxxxx>
---
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