diff mbox series

[1/8] apparmor: just use vfs_kern_mount to make .null

Message ID 20200414124304.4470-2-eesposit@redhat.com (mailing list archive)
State New, archived
Headers show
Series Simplefs: group and simplify linux fs code | expand

Commit Message

Emanuele Giuseppe Esposito April 14, 2020, 12:42 p.m. UTC
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.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 security/apparmor/apparmorfs.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Luis Chamberlain April 16, 2020, 6:44 a.m. UTC | #1
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
>
Emanuele Giuseppe Esposito April 20, 2020, 2 p.m. UTC | #2
On 4/16/20 8:44 AM, Luis Chamberlain wrote:
> 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?

The refcount is a local variable and is always 0 on entry and exit, so 
it is not necessary to have refcounting across function invocations, 
such as what simple_pin_fs and simple_release_fs provide.

Thank you,

Emanuele
> 
>     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
>>
>
diff mbox series

Patch

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;
 }