From: Luis Chamberlain <mcgrof@kernel•org>
To: Emanuele Giuseppe Esposito <eesposit@redhat•com>,
Goldwyn Rodrigues <goldwynr@gmail•com>
Cc: Song Liu <songliubraving@fb•com>,
linux-usb@vger•kernel.org, bpf@vger•kernel.org,
"Rafael J. Wysocki" <rafael@kernel•org>,
David Airlie <airlied@linux•ie>,
Heiko Carstens <heiko.carstens@de•ibm.com>,
Alexei Starovoitov <ast@kernel•org>,
dri-devel@lists•freedesktop.org,
"J. Bruce Fields" <bfields@fieldses•org>,
Joseph Qi <joseph.qi@linux•alibaba.com>,
Hugh Dickins <hughd@google•com>,
Paul Mackerras <paulus@samba•org>,
John Johansen <john.johansen@canonical•com>,
netdev@vger•kernel.org, linux-s390@vger•kernel.org,
ocfs2-devel@oss•oracle.com, Christoph Hellwig <hch@lst•de>,
Andrew Donnellan <ajd@linux•ibm.com>,
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"Martin K. Petersen" <martin.petersen@oracle•com>,
linux-mm@kvack•org,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
Dennis Dalessandro <dennis.dalessandro@intel•com>,
Miklos Szeredi <miklos@szeredi•hu>,
linux-kernel@vger•kernel.org,
Anna Schumaker <anna.schumaker@netapp•com>,
linux-security-module@vger•kernel.org,
Chuck Lever <chuck.lever@oracle•com>, Jeremy Kerr <jk@ozlabs•org>,
Daniel Vetter <daniel@ffwll•ch>, Colin Cross <ccross@android•com>,
Frederic Barrat <fbarrat@linux•ibm.com>,
Paolo Bonzini <pbonzini@redhat•com>,
Andrew Morton <akpm@linux-foundation•org>,
Mike Kravetz <mike.kravetz@oracle•com>,
linuxppc-dev@lists•ozlabs.org, Martin KaFai Lau <kafai@fb•com>,
Joel Becker <jlbec@evilplan•org>,
Alexander Viro <viro@zeniv•linux.org.uk>
Subject: Re: [PATCH 1/8] apparmor: just use vfs_kern_mount to make .null
Date: Thu, 16 Apr 2020 06:44:05 +0000 [thread overview]
Message-ID: <20200416064405.GP11244@42.do-not-panic.com> (raw)
In-Reply-To: <20200414124304.4470-2-eesposit@redhat.com>
On Tue, Apr 14, 2020 at 02:42:55PM +0200, Emanuele Giuseppe Esposito wrote:
> 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.
*Why* is refcounting not needed here?
Luis
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat•com>
> ---
> security/apparmor/apparmorfs.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index 280741fc0f5f..828bb1eb77ea 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -2525,14 +2525,14 @@ 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);
>
> - 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 +2561,7 @@ 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
>
next prev parent reply other threads:[~2020-04-16 8:23 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 12:42 [PATCH 0/8] Simplefs: group and simplify linux fs code Emanuele Giuseppe Esposito
2020-04-14 12:42 ` [PATCH 1/8] apparmor: just use vfs_kern_mount to make .null Emanuele Giuseppe Esposito
2020-04-16 6:44 ` Luis Chamberlain [this message]
2020-04-20 14:00 ` Emanuele Giuseppe Esposito
2020-04-14 12:42 ` [PATCH 2/8] fs: extract simple_pin/release_fs to separate files Emanuele Giuseppe Esposito
2020-04-14 12:54 ` Greg Kroah-Hartman
2020-04-16 6:52 ` Luis Chamberlain
2020-04-21 11:19 ` Frederic Barrat
2020-04-21 11:26 ` Emanuele Giuseppe Esposito
2020-04-14 12:42 ` [PATCH 3/8] fs: wrap simple_pin_fs/simple_release_fs arguments in a struct Emanuele Giuseppe Esposito
2020-04-14 13:03 ` Greg Kroah-Hartman
2020-04-14 12:42 ` [PATCH 4/8] fs: introduce simple_new_inode Emanuele Giuseppe Esposito
2020-04-14 13:01 ` Greg Kroah-Hartman
2020-04-20 13:58 ` Emanuele Giuseppe Esposito
2020-04-14 12:42 ` [PATCH 5/8] simplefs: add alloc_anon_inode wrapper Emanuele Giuseppe Esposito
2020-04-14 12:55 ` Greg Kroah-Hartman
2020-04-14 12:43 ` [PATCH 6/8] simplefs: add file creation functions Emanuele Giuseppe Esposito
2020-04-14 12:56 ` Greg Kroah-Hartman
2020-04-20 13:57 ` Emanuele Giuseppe Esposito
2020-04-20 14:28 ` Greg Kroah-Hartman
2020-04-20 14:33 ` Paolo Bonzini
2020-04-14 12:43 ` [PATCH 7/8] debugfs: switch to simplefs inode creation API Emanuele Giuseppe Esposito
2020-04-14 12:43 ` [PATCH 8/8] tracefs: " Emanuele Giuseppe Esposito
2020-04-16 6:59 ` [PATCH 0/8] Simplefs: group and simplify linux fs code Luis Chamberlain
2020-04-20 14:01 ` Emanuele Giuseppe Esposito
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