From nobody Sun Feb 8 22:06:18 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D316C761A6 for ; Mon, 27 Mar 2023 14:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232008AbjC0OCy (ORCPT ); Mon, 27 Mar 2023 10:02:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232381AbjC0OCn (ORCPT ); Mon, 27 Mar 2023 10:02:43 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DA6E3C00; Mon, 27 Mar 2023 07:02:38 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4PlZJT3qWrz4f3l8l; Mon, 27 Mar 2023 22:02:33 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.127.227]) by APP3 (Coremail) with SMTP id _Ch0CgDn4R_5oSFkbm6iFg--.46084S4; Mon, 27 Mar 2023 22:02:35 +0800 (CST) From: Ye Bin To: djwong@kernel.org, linux-xfs@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ye Bin Subject: [PATCH] xfs: fix BUG_ON in xfs_getbmap() Date: Mon, 27 Mar 2023 22:02:18 +0800 Message-Id: <20230327140218.4154709-1-yebin@huaweicloud.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _Ch0CgDn4R_5oSFkbm6iFg--.46084S4 X-Coremail-Antispam: 1UD129KBjvJXoWxGFy5Gw1UurWxJr43ZFWUurg_yoW5tw13pr 93Kw1UGr4vqr1UZr1kJw1jgw1UGw17CF4rZr1xWr1xX3WUCr17tr40kFWfAFyUJrWxZryf tr1DJw18t345JaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUgKb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Y z7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zV AF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4l IxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s 0DMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBI daVFxhVjvjDU0xZFpf9x07UE-erUUUUU= X-CM-SenderInfo: p1hex046kxt4xhlfz01xgou0bp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Ye Bin There's issue as follows: XFS: Assertion failed: (bmv->bmv_iflags & BMV_IF_DELALLOC) !=3D 0, file: fs= /xfs/xfs_bmap_util.c, line: 329 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 14612 Comm: xfs_io Not tainted 6.3.0-rc2-next-20230315-00006-g2= 729d23ddb3b-dirty #422 RIP: 0010:assfail+0x96/0xa0 RSP: 0018:ffffc9000fa178c0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888179a18000 RDX: 0000000000000000 RSI: ffff888179a18000 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffffffff8321aab6 R09: 0000000000000000 R10: 0000000000000001 R11: ffffed1105f85139 R12: ffffffff8aacc4c0 R13: 0000000000000149 R14: ffff888269f58000 R15: 000000000000000c FS: 00007f42f27a4740(0000) GS:ffff88882fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000b92388 CR3: 000000024f006000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: xfs_getbmap+0x1a5b/0x1e40 xfs_ioc_getbmap+0x1fd/0x5b0 xfs_file_ioctl+0x2cb/0x1d50 __x64_sys_ioctl+0x197/0x210 do_syscall_64+0x39/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue may happen as follows: ThreadA ThreadB do_shared_fault __do_fault xfs_filemap_fault __xfs_filemap_fault filemap_fault xfs_ioc_getbmap -> Without BMV_IF_DELALLOC flag xfs_getbmap xfs_ilock(ip, XFS_IOLOCK_SHARED); filemap_write_and_wait do_page_mkwrite xfs_filemap_page_mkwrite __xfs_filemap_fault xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); iomap_page_mkwrite ... xfs_buffered_write_iomap_begin xfs_bmapi_reserve_delalloc -> Allocate delay extent xfs_ilock_data_map_shared(ip) xfs_getbmap_report_one ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) !=3D 0) -> trigger BUG_ON As xfs_filemap_page_mkwrite() only hold XFS_MMAPLOCK_SHARED lock, there's small window mkwrite can produce delay extent after file write in xfs_getbm= ap(). To solve above issue, hold XFS_MMAPLOCK_EXCL lock when do xfs_getbmap(), to prevent write operations by do_page_mkwrite(). During doing __xfs_filemap_fault() we can't hold IOLOCK lock, as it's may l= ead to ABBA dealock with xfs_file_write_iter().It's very easy to reproduce when do fsstress, lockdep will detect deadlock. Signed-off-by: Ye Bin --- fs/xfs/xfs_bmap_util.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index a09dd2606479..f23771a0cc8d 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -463,11 +463,13 @@ xfs_getbmap( max_len =3D XFS_ISIZE(ip); break; case XFS_DATA_FORK: + lock =3D XFS_MMAPLOCK_EXCL; + xfs_ilock(ip, lock); if (!(iflags & BMV_IF_DELALLOC) && (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_size)) { error =3D filemap_write_and_wait(VFS_I(ip)->i_mapping); if (error) - goto out_unlock_iolock; + goto out_unlock_ilock; =20 /* * Even after flushing the inode, there can still be @@ -486,7 +488,7 @@ xfs_getbmap( else max_len =3D XFS_ISIZE(ip); =20 - lock =3D xfs_ilock_data_map_shared(ip); + lock |=3D xfs_ilock_data_map_shared(ip); break; } =20 --=20 2.31.1