Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Yu Zhao <yuzhao@google.com>, Hugh Dickins <hughd@google.com>
Subject: [PATCH v11 49/69] fork: use VMA iterator
Thread-Topic: [PATCH v11 49/69] fork: use VMA iterator
Thread-Index: AQHYmYd401qZSF+Upk+wV/ProxkEAA==
Date:   Sun, 17 Jul 2022 02:46:53 +0000
Message-ID: <20220717024615.2106835-50-Liam.Howlett@oracle.com>
References: <20220717024615.2106835-1-Liam.Howlett@oracle.com>
In-Reply-To: <20220717024615.2106835-1-Liam.Howlett@oracle.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?iso-8859-1?Q?wRiFjnCMf9rpoIo/wBr32VaOa9npRbfXt4GMFxnez2wyv9yQkipMle3eQT?=
 =?iso-8859-1?Q?9XX6W+KWEpp21fQcya359vwWuZCa87lrSdPCdO4Bq6tPhAeDBhDxmO8+dE?=
 =?iso-8859-1?Q?1HoirMaBhp4hcmK8pbnU/12WNHGoCj8qAGvf+EjUgFJJ0fkhX+mwX83UDf?=
 =?iso-8859-1?Q?zhAmYAvkOCIIBzSGA5boBvnWXlJg0xzIWMsMUrfqhjpPvHte6oNq3DTFak?=
 =?iso-8859-1?Q?sTrwdJ8LI6MtpxYJ0yVh9A6GFai7n6gfnj69LtsafzutJfmGXVyT+uZqk2?=
 =?iso-8859-1?Q?fVhy0/ZXQof7IbcMNuLrDDeiDNZyNmdE7qx/ezkGZQP3/p9iXeaeMtdc+v?=
 =?iso-8859-1?Q?RES+WDd/JusjX+gvxJaXSUTTrCr3ALYGEGFYfxYZWAaQQxuy3mQ5Bd14bj?=
 =?iso-8859-1?Q?bUKzNxm26OdyJ6CA47zRnwY8fvbQuv+UfnaAN7fKd/KmAgBQHqAhnGxsfT?=
 =?iso-8859-1?Q?3WjJobWR5+4Bmly6YVWUnM7rTDFBTUZY8bBOLWhF44GfeVCWcZuUMr6TJc?=
 =?iso-8859-1?Q?cvxesbLKArqlX4yH0o5W/ylhZBcU5EkT+/CE/zdM40+fHy0NJuFKLjxfIU?=
 =?iso-8859-1?Q?Z/dm2sIqfkE/DWDSL9AZyXAA/WiJEMOTq/85wH+HGl78XlfiU9i8Ge+vON?=
 =?iso-8859-1?Q?Jb8gT6O06D4KFp+9txDHas/kIGc6gclCpoC3THZynxkdjWzXTGV5FXz4mR?=
 =?iso-8859-1?Q?m2/TeI8zPoTILP3fK6W05xsbFJEBmT8zu4rfFJyUqyLn/NJHABMKNCvZ7k?=
 =?iso-8859-1?Q?LM6acKLzGu08sY+5e0TQLd4lGUNbu8Kbck5HRqs2UXdctoTNJa8CmxkOoF?=
 =?iso-8859-1?Q?rYl8ybqY8cW4UpQGKhLv3sT1LBy4tfnfL7p6Ca8V7u+8IZmFAPkcRbPAAZ?=
 =?iso-8859-1?Q?XnmchIvuJ4eNk2HOCSuwyqinMwql+F3LK0OA6IfhhIQ49bfkxmGbJcxlYz?=
 =?iso-8859-1?Q?BOgAvJ4GqLDa268iBhD0hwNvvJlr/JvY+JKMQVby0jziYSr2L3Kg5DopXB?=
 =?iso-8859-1?Q?2uXaqKz89Hv4vSXJB59hivUv4Gv0sPXKFpErIxsRD7ye0NJoQXMICGHDyG?=
 =?iso-8859-1?Q?rymQQZqBZ//FbKUrG4PN2he2pzklxLl4cdE4v0lIhtE9zZJX9giCrSUJ0d?=
 =?iso-8859-1?Q?YAczFdgdqkm4dtmWVQxp9OfgM99AeyzOi/iC6CAMNKAHH1Q556U9mcxoVx?=
 =?iso-8859-1?Q?UkkwnQm7l0vd0bb2Ftyap7yPdEtikr5dM39BV/2X3KyUZ3pc+3nE1qZ3Wx?=
 =?iso-8859-1?Q?6t0TYyWv5K/WmdJl1AJrIwbyjBGe7ChezWRWm6m4I40oRahNsSiT2x1T0i?=
 =?iso-8859-1?Q?JxFz/uFeBl3Pzb+Il62hF/2zedO9cqXaKd/XAKBDNwr6jAMaou6ir0ts0s?=
 =?iso-8859-1?Q?SmeB0hQK3VX2939rqmoGQce/W0ClVRJY6TMWNrWA2kuyPQqbcHUMfv7yKY?=
 =?iso-8859-1?Q?vYVhdBzEPq6dwrb8vUxU0ufYgLf6WzluTQbAeseJjxp0+ccWtySsdxabI3?=
 =?iso-8859-1?Q?CbRrpcQwZ4uHRVJDLlbdEDImnE8chB4e4ByPl9eJevHaVt0um7G5tNVoE2?=
 =?iso-8859-1?Q?K7MC/CC2nYnXm4kljjzlvoAm2hbtnxv7o298oLShLJQ3NIbVEZ0PALvlNr?=
 =?iso-8859-1?Q?ZlbHCTM085mKCQxNQh4C94FMICvODffhLe6xHGviow5O3Eer9dTid2KA?=
 =?iso-8859-1?Q?=3D=3D?=
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: b0d4e3ae-d0af-4435-9d25-08da679eb111
X-MS-Exchange-CrossTenant-originalarrivaltime: 17 Jul 2022 02:46:53.4117
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: 6wrGKfnxgGV3RloxPrMqQTPmGEXFTuTKImqYjignjp0/ErEeoQv+7RZdf8sqyazkPxDIs7gzUIKtDUjPOEStQw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR10MB4504
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1
 definitions=2022-07-17_01,2022-07-15_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 mlxlogscore=999
 suspectscore=0 phishscore=0 adultscore=0 spamscore=0 malwarescore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000
 definitions=main-2207170010
X-Proofpoint-GUID: G2FWFTjtbKhgWAktP-ih02RH54uYA4PN
X-Proofpoint-ORIG-GUID: G2FWFTjtbKhgWAktP-ih02RH54uYA4PN
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

The VMA iterator is faster than the linked list and removing the linked
list will shrink the vm_area_struct.

Link: https://lkml.kernel.org/r/20220504011345.662299-34-Liam.Howlett@oracl=
e.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-50-Liam.Howlett@orac=
le.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 kernel/fork.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 4a9fce369f30..4b7b0b7dd446 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1294,13 +1294,16 @@ int replace_mm_exe_file(struct mm_struct *mm, struc=
t file *new_exe_file)
 	/* Forbid mm->exe_file change if old file still mapped. */
 	old_exe_file =3D get_mm_exe_file(mm);
 	if (old_exe_file) {
+		VMA_ITERATOR(vmi, mm, 0);
 		mmap_read_lock(mm);
-		for (vma =3D mm->mmap; vma && !ret; vma =3D vma->vm_next) {
+		for_each_vma(vmi, vma) {
 			if (!vma->vm_file)
 				continue;
 			if (path_equal(&vma->vm_file->f_path,
-				       &old_exe_file->f_path))
+				       &old_exe_file->f_path)) {
 				ret =3D -EBUSY;
+				break;
+			}
 		}
 		mmap_read_unlock(mm);
 		fput(old_exe_file);
--=20
2.35.1