From patchwork Mon Jun 22 09:30:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Xiaoxu X-Patchwork-Id: 11617327 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 96E6690 for ; Mon, 22 Jun 2020 09:29:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8733A2071A for ; Mon, 22 Jun 2020 09:29:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbgFVJ3A (ORCPT ); Mon, 22 Jun 2020 05:29:00 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:6305 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725819AbgFVJ27 (ORCPT ); Mon, 22 Jun 2020 05:28:59 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 2DB66146E313D41E4EC1; Mon, 22 Jun 2020 17:28:57 +0800 (CST) Received: from localhost.localdomain (10.175.101.6) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Mon, 22 Jun 2020 17:28:49 +0800 From: Zhang Xiaoxu To: , CC: , Subject: [PATCH] cifs: Fix double add page to memcg when cifs_readpages Date: Mon, 22 Jun 2020 05:30:19 -0400 Message-ID: <20200622093019.1535800-1-zhangxiaoxu5@huawei.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-CFilter-Loop: Reflected Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org When xfstests generic/451, there is an BUG at mm/memcontrol.c: page:ffffea000560f2c0 refcount:2 mapcount:0 mapping:000000008544e0ea index:0xf mapping->aops:cifs_addr_ops dentry name:"tst-aio-dio-cycle-write.451" flags: 0x2fffff80000001(locked) raw: 002fffff80000001 ffffc90002023c50 ffffea0005280088 ffff88815cda0210 raw: 000000000000000f 0000000000000000 00000002ffffffff ffff88817287d000 page dumped because: VM_BUG_ON_PAGE(page->mem_cgroup) page->mem_cgroup:ffff88817287d000 ------------[ cut here ]------------ kernel BUG at mm/memcontrol.c:2659! invalid opcode: 0000 [#1] SMP CPU: 2 PID: 2038 Comm: xfs_io Not tainted 5.8.0-rc1 #44 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_ 073836-buildvm-ppc64le-16.ppc.4 RIP: 0010:commit_charge+0x35/0x50 Code: 0d 48 83 05 54 b2 02 05 01 48 89 77 38 c3 48 c7 c6 78 4a ea ba 48 83 05 38 b2 02 05 01 e8 63 0d9 RSP: 0018:ffffc90002023a50 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88817287d000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88817ac97ea0 RDI: ffff88817ac97ea0 RBP: ffffea000560f2c0 R08: 0000000000000203 R09: 0000000000000005 R10: 0000000000000030 R11: ffffc900020237a8 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: ffff88815a1272c0 FS: 00007f5071ab0800(0000) GS:ffff88817ac80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055efcd5ca000 CR3: 000000015d312000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mem_cgroup_charge+0x166/0x4f0 __add_to_page_cache_locked+0x4a9/0x710 add_to_page_cache_locked+0x15/0x20 cifs_readpages+0x217/0x1270 read_pages+0x29a/0x670 page_cache_readahead_unbounded+0x24f/0x390 __do_page_cache_readahead+0x3f/0x60 ondemand_readahead+0x1f1/0x470 page_cache_async_readahead+0x14c/0x170 generic_file_buffered_read+0x5df/0x1100 generic_file_read_iter+0x10c/0x1d0 cifs_strict_readv+0x139/0x170 new_sync_read+0x164/0x250 __vfs_read+0x39/0x60 vfs_read+0xb5/0x1e0 ksys_pread64+0x85/0xf0 __x64_sys_pread64+0x22/0x30 do_syscall_64+0x69/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5071fcb1af Code: Bad RIP value. RSP: 002b:00007ffde2cdb8e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000011 RAX: ffffffffffffffda RBX: 00007ffde2cdb990 RCX: 00007f5071fcb1af RDX: 0000000000001000 RSI: 000055efcd5ca000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000293 R12: 0000000000000001 R13: 000000000009f000 R14: 0000000000000000 R15: 0000000000001000 Modules linked in: ---[ end trace 725fa14a3e1af65c ]--- Since commit 3fea5a499d57 ("mm: memcontrol: convert page cache to a new mem_cgroup_charge() API") not cancel the page charge, the pages maybe double add to pagecache: thread1 | thread2 cifs_readpages readpages_get_pages add_to_page_cache_locked(head,index=n)=0 | readpages_get_pages | add_to_page_cache_locked(head,index=n+1)=0 add_to_page_cache_locked(head, index=n+1)=-EEXIST then, will next loop with list head page's index=n+1 and the page->mapping not NULL readpages_get_pages add_to_page_cache_locked(head, index=n+1) commit_charge VM_BUG_ON_PAGE So, we should not do the next loop when any page add to page cache failed. Reported-by: Hulk Robot Signed-off-by: Zhang Xiaoxu Acked-by: Ronnie Sahlberg --- fs/cifs/file.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 4fe757cfc360..9b0f8f33f832 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -4336,7 +4336,8 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, break; __SetPageLocked(page); - if (add_to_page_cache_locked(page, mapping, page->index, gfp)) { + rc = add_to_page_cache_locked(page, mapping, page->index, gfp); + if (rc) { __ClearPageLocked(page); break; } @@ -4352,6 +4353,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, struct list_head *page_list, unsigned num_pages) { int rc; + int err = 0; struct list_head tmplist; struct cifsFileInfo *open_file = file->private_data; struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); @@ -4396,7 +4398,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, * the order of declining indexes. When we put the pages in * the rdata->pages, then we want them in increasing order. */ - while (!list_empty(page_list)) { + while (!list_empty(page_list) && !err) { unsigned int i, nr_pages, bytes, rsize; loff_t offset; struct page *page, *tpage; @@ -4429,9 +4431,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, return 0; } - rc = readpages_get_pages(mapping, page_list, rsize, &tmplist, + nr_pages = 0; + err = readpages_get_pages(mapping, page_list, rsize, &tmplist, &nr_pages, &offset, &bytes); - if (rc) { + if (!nr_pages) { add_credits_and_wake_if(server, credits, 0); break; }