Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <470a8f03-02aa-4e74-ab69-7722db1b619f@intel.com>
Date:   Thu, 14 Dec 2023 08:42:45 -0700
User-Agent: Betterbird (Linux)
Subject: Re: [PATCH] [v2] nvdimm-btt: simplify code with the scope based
 resource management
To:     Dinghao Liu <dinghao.liu@zju.edu.cn>
CC:     Dan Williams <dan.j.williams@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Ira Weiny <ira.weiny@intel.com>, <nvdimm@lists.linux.dev>,
        <linux-kernel@vger.kernel.org>
References: <20231214083919.22218-1-dinghao.liu@zju.edu.cn>
Content-Language: en-US
From:   Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <20231214083919.22218-1-dinghao.liu@zju.edu.cn>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?c2JJaXpsOUhxdEtaLzNLYWFYZFR2VUxUb05HbTBqT1UzZzV2TGFyUUxGOEd2?=
 =?utf-8?B?TGI5cVFWdVVoWWRVUk8rK3M2QkhUdUdIVGpsUm01VmxlV0J1YVo2V1dwY2pm?=
 =?utf-8?B?cXZ4ZGd0ajNnbHUvMnE1TzNUUFFxMEUrdnFWVUJHS3Fla2t3Z1hxdEhPcSty?=
 =?utf-8?B?aTJRRTJENmFKRUVhZFFIc1haUzhqZnBmSEpRYXpJaEhCUldudTlkOGFySE5m?=
 =?utf-8?B?bHhhTHJneDdqQUhhZGphNFk0NitCNzVteURsaVFWZ01yVW5xN2F0cGNibXFa?=
 =?utf-8?B?RDZudVpVMkZmZ3ZHdkVoSXZCTnI0MUpHZG43ODk4aDdiUUw0aExNSWpFTDZm?=
 =?utf-8?B?b3dGMy9ML0pQRE5PMEJabGFLTk9GdTRDd2FMaFF0Mzg5dGo5YlN0THEzNnRZ?=
 =?utf-8?B?MGMvdEdTVndmaGt4bWttb2pwYmJSWUZ0Y1lHbGwxWFBQWGx5RUhuSnEvTmVu?=
 =?utf-8?B?K2NYYmRIU2t2WU1Cd2VPR0djYzNwRVJnL3dhaEZ0NmdSSVJ5dG9xQWJjMVpY?=
 =?utf-8?B?cDBCWUtjT3l4dVhRREh6QzJ6czhsNWxqWUFkT2didE52cjR4eEVTZ1paaU9i?=
 =?utf-8?B?UEdFSkxIL05naWp3emMrWEtkYVRDNmo0OUw3UkVBQmM4RjJ5QXFsWVNmQTRu?=
 =?utf-8?B?eTdMWWYwVlBnUDcvZmhieU85QmdOUHNUYjdneW45NE1US255R2JQL1laMzg3?=
 =?utf-8?B?NE9FNFM0K3kramd5WUVUMWtpdkM4QlJsVjY4TU56SG1rUGx1MWVPZ1JIZ2xO?=
 =?utf-8?B?N3V0RURVT1ZkbGhOck9xelRERFYyMll2K3dsZVdxTUFnTU1VWkhhdFhNRlFo?=
 =?utf-8?B?enVMcXo5M2RuN2dNSHdhWVlBWUIxYWhnMExRL1B6RzBuQU9scE1YMDZESkV0?=
 =?utf-8?B?L3M0QndYZUxaYitiRGd4cTA2VDBMSzN2QzIyczlmK3NEeWVLWlNsQnpUamdM?=
 =?utf-8?B?dzVsNlN3bG9qcVRzY1p2enY0VjgvdUJwUWhLWDhzRHJVVnhyOStvdWJxVjRl?=
 =?utf-8?B?VFY3cUc4R2FwZU9rU01HMTdwUm9TdzZ4R0ZlUjRHWEZ1eDBmUDluUmdVZGdj?=
 =?utf-8?B?R0x0QnBGYzJPdGp4U2ZXMldndTNFVk14QmNYVjJiazNidG1CcHhYdGRkMWNz?=
 =?utf-8?B?RGYydG5mVmlPRlVhT3dzdktTMXRlL2h1YkpyZVFaYUhuMStWU3lWZGc1M1dZ?=
 =?utf-8?B?dE5BeVM1b3VpaCs3WXF1OWU3RVhxZGR4M2UybzlHN2VWN3ZVcWlVYTJnZG5v?=
 =?utf-8?B?aURWQ1lZWDg2UVBFclEwUFY0SGVoQkNhUzA1RGdLblNBa0tNV0IrZUxQWTVs?=
 =?utf-8?B?aTRiRHdRUEM1T3crUFcwZHhiWkZCd3RJRFkwbER3ZEZ4RzlGTENmWUlNQXFZ?=
 =?utf-8?B?QmtuL2pqOWRJQXUzVVF4SlRKUitzNDNRVndDU3hYVm94WmNvWkxyYWgwbEFL?=
 =?utf-8?B?bmZHQWc1MGFsYStQUW9iZWpSYWhVdlVSUzROMG43Sm5kN2ZCQ2JZS0RoRmtI?=
 =?utf-8?B?dkVLTE1aaVIwQ2FrRVJwZXF2ZEp5eEFiY1lUa0F0dXpqNEZlc0FXa3I1YmY3?=
 =?utf-8?B?MlcwRVdhWmFGUEpIVDN1OVh5aGUyK3k5R1FEc3FuaXluU25Maiswb1BkUDJp?=
 =?utf-8?B?dHBWNXgzd05CVTJ4aFlnVVpERlBxMHgxVWJpbVE2NXRFUUhOTkhqenFxWnVi?=
 =?utf-8?B?aEcrOTBPVkVQSittcE5Fb0lMYTJXaUdjaG1EOFFIazZ2Z2d0Z0VRNzlsdEZT?=
 =?utf-8?B?d0pSRTFOQlBvWFZXTlVFQzVNTW9SZ291ZTIwNXFJejZXVFpqbnFvY1djWUVm?=
 =?utf-8?B?R3RvakdOWjZLK216WDAvRW5jb0hFZzVxNGdUS2tpMHRaZXA1YkdJTmdwM0Fo?=
 =?utf-8?B?V2pmUHc0NzNBb0xpVTk1cFdjMkhiS3pZR1VwOUY4blNNa3VmdHJGaUJ2eHJF?=
 =?utf-8?B?WXc0bzJ0T2l5TzBEMU0yb0NHZmhjZFhUUXQrcU5pMURFU0NyQTNwYTBGcjVh?=
 =?utf-8?B?U3ZmeGxqQUtDMENaYUxYQm9qUkdwUVU2UXJUWndDT3E3ZXNvWnorZisyN1ZC?=
 =?utf-8?B?dGQxeVZKbnVwcHZFTUxNVXovWjBZa1NsMEJTcEpKamlWZzQwR3dHWXhFL3FS?=
 =?utf-8?Q?XWOmx4Uu3gWeZ2UIKudbNzoJw?=
X-MS-Exchange-CrossTenant-Network-Message-Id: a44e21f3-121d-4510-1592-08dbfcbb5278
X-MS-Exchange-CrossTenant-AuthSource: PH7PR11MB5984.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Dec 2023 15:42:47.8522
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: zxkMO3YnLUErM5abGoXl04CngLXMh/eRUCV6oxZcldm3XI97ZrGUOraHCDNydxiG7HgAccm8VNXR9PEOl9QDrg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR11MB6921
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on howler.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Thu, 14 Dec 2023 07:43:04 -0800 (PST)


On 12/14/23 01:39, Dinghao Liu wrote:
> Use the scope based resource management (defined in
> linux/cleanup.h) to automate resource lifetime
> control on struct btt_sb *super in discover_arenas().
> 
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
> 
> Changelog:
> 
> v2: Set the __free attribute before kzalloc.
> ---
>  drivers/nvdimm/btt.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
> index d5593b0dc700..32a9e2f543c5 100644
> --- a/drivers/nvdimm/btt.c
> +++ b/drivers/nvdimm/btt.c
> @@ -16,6 +16,7 @@
>  #include <linux/fs.h>
>  #include <linux/nd.h>
>  #include <linux/backing-dev.h>
> +#include <linux/cleanup.h>
>  #include "btt.h"
>  #include "nd.h"
>  
> @@ -847,23 +848,20 @@ static int discover_arenas(struct btt *btt)
>  {
>  	int ret = 0;
>  	struct arena_info *arena;
> -	struct btt_sb *super;
>  	size_t remaining = btt->rawsize;
>  	u64 cur_nlba = 0;
>  	size_t cur_off = 0;
>  	int num_arenas = 0;
>  
> -	super = kzalloc(sizeof(*super), GFP_KERNEL);
> +	struct btt_sb *super __free(kfree) = kzalloc(sizeof(*super), GFP_KERNEL);
>  	if (!super)
>  		return -ENOMEM;
>  
>  	while (remaining) {
>  		/* Alloc memory for arena */
>  		arena = alloc_arena(btt, 0, 0, 0);
> -		if (!arena) {
> -			ret = -ENOMEM;
> -			goto out_super;
> -		}
> +		if (!arena)
> +			return -ENOMEM;
>  
>  		arena->infooff = cur_off;
>  		ret = btt_info_read(arena, super);
> @@ -919,14 +917,11 @@ static int discover_arenas(struct btt *btt)
>  	btt->nlba = cur_nlba;
>  	btt->init_state = INIT_READY;
>  
> -	kfree(super);
>  	return ret;
>  
>   out:
>  	kfree(arena);
>  	free_arenas(btt);
> - out_super:
> -	kfree(super);
>  	return ret;
>  }
>