From nobody Sun May 5 08:57:14 2024 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 DF06CC433EF for ; Mon, 23 May 2022 14:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236897AbiEWODq (ORCPT ); Mon, 23 May 2022 10:03:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236860AbiEWODa (ORCPT ); Mon, 23 May 2022 10:03:30 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E49F52E73; Mon, 23 May 2022 07:03:29 -0700 (PDT) Received: from dggpeml500020.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4L6JrD0jkZzQk8X; Mon, 23 May 2022 22:00:28 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500020.china.huawei.com (7.185.36.88) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 23 May 2022 22:03:26 +0800 From: Baokun Li To: CC: , , , , , , , , , , Hulk Robot Subject: [PATCH v2 1/2] ext4: fix bug_on ext4_mb_use_inode_pa Date: Mon, 23 May 2022 22:16:57 +0800 Message-ID: <20220523141658.2919003-2-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220523141658.2919003-1-libaokun1@huawei.com> References: <20220523141658.2919003-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500020.china.huawei.com (7.185.36.88) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Hulk Robot reported a BUG_ON: =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D kernel BUG at fs/ext4/mballoc.c:3211! [...] RIP: 0010:ext4_mb_mark_diskspace_used.cold+0x85/0x136f [...] Call Trace: ext4_mb_new_blocks+0x9df/0x5d30 ext4_ext_map_blocks+0x1803/0x4d80 ext4_map_blocks+0x3a4/0x1a10 ext4_writepages+0x126d/0x2c30 do_writepages+0x7f/0x1b0 __filemap_fdatawrite_range+0x285/0x3b0 file_write_and_wait_range+0xb1/0x140 ext4_sync_file+0x1aa/0xca0 vfs_fsync_range+0xfb/0x260 do_fsync+0x48/0xa0 [...] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Above issue may happen as follows: Reported-by: Hulk Robot Reported-by: kernel test robot ------------------------------------- do_fsync vfs_fsync_range ext4_sync_file file_write_and_wait_range __filemap_fdatawrite_range do_writepages ext4_writepages mpage_map_and_submit_extent mpage_map_one_extent ext4_map_blocks ext4_mb_new_blocks ext4_mb_normalize_request >>> start + size <=3D ac->ac_o_ex.fe_logical ext4_mb_regular_allocator ext4_mb_simple_scan_group ext4_mb_use_best_found ext4_mb_new_preallocation ext4_mb_new_inode_pa ext4_mb_use_inode_pa >>> set ac->ac_b_ex.fe_len <=3D 0 ext4_mb_mark_diskspace_used >>> BUG_ON(ac->ac_b_ex.fe_len <=3D 0); we can easily reproduce this problem with the following commands: `fallocate -l100M disk` `mkfs.ext4 -b 1024 -g 256 disk` `mount disk /mnt` `fsstress -d /mnt -l 0 -n 1000 -p 1` The size must be smaller than or equal to EXT4_BLOCKS_PER_GROUP. Therefore, "start + size <=3D ac->ac_o_ex.fe_logical" may occur when the size is truncated. So start should be the start position of the group where ac_o_ex.fe_logical is located after alignment. In addition, when the value of fe_logical or EXT4_BLOCKS_PER_GROUP is very large, the value calculated by start_off is more accurate. Fixes: cd648b8a8fd5 ("ext4: trim allocation requests to group size") Reported-by: Hulk Robot Signed-off-by: Baokun Li --- V1->V2: Replace round_down() with rounddown(). Modified comments. fs/ext4/mballoc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 9f12f29bc346..6aafc242fe23 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4104,6 +4104,15 @@ ext4_mb_normalize_request(struct ext4_allocation_con= text *ac, size =3D size >> bsbits; start =3D start_off >> bsbits; =20 + /* + * For tiny groups (smaller than 8MB) the chosen allocation + * alignment may be larger than group size. Make sure the + * alignment does not move allocation to a different group which + * makes mballoc fail assertions later. + */ + start =3D max(start, rounddown(ac->ac_o_ex.fe_logical, + EXT4_BLOCKS_PER_GROUP(ac->ac_sb))); + /* don't cover already allocated blocks in selected range */ if (ar->pleft && start <=3D ar->lleft) { size -=3D ar->lleft + 1 - start; --=20 2.31.1 From nobody Sun May 5 08:57:14 2024 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 5AE5AC433F5 for ; Mon, 23 May 2022 14:03:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236917AbiEWODv (ORCPT ); Mon, 23 May 2022 10:03:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236862AbiEWODb (ORCPT ); Mon, 23 May 2022 10:03:31 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B08C123163; Mon, 23 May 2022 07:03:30 -0700 (PDT) Received: from dggpeml500020.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4L6Jt04Slrz1JC8d; Mon, 23 May 2022 22:02:00 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500020.china.huawei.com (7.185.36.88) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 23 May 2022 22:03:28 +0800 From: Baokun Li To: CC: , , , , , , , , , Subject: [PATCH v2 2/2] ext4: correct the judgment of BUG in ext4_mb_normalize_request Date: Mon, 23 May 2022 22:16:58 +0800 Message-ID: <20220523141658.2919003-3-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220523141658.2919003-1-libaokun1@huawei.com> References: <20220523141658.2919003-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500020.china.huawei.com (7.185.36.88) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When either of the "start + size <=3D ac->ac_o_ex.fe_logical" or "start > ac->ac_o_ex.fe_logical" conditions is met, it indicates that the fe_logical is not in the allocated range. In this case, it should be bug_ON. Fixes: c9de560ded61 ("ext4: Add multi block allocator for ext4") Signed-off-by: Baokun Li --- V1->V2: Change Fixes from dfe076c106f6 to c9de560ded61. fs/ext4/mballoc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 6aafc242fe23..61ced468f178 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4185,7 +4185,7 @@ ext4_mb_normalize_request(struct ext4_allocation_cont= ext *ac, } rcu_read_unlock(); =20 - if (start + size <=3D ac->ac_o_ex.fe_logical && + if (start + size <=3D ac->ac_o_ex.fe_logical || start > ac->ac_o_ex.fe_logical) { ext4_msg(ac->ac_sb, KERN_ERR, "start %lu, size %lu, fe_logical %lu", --=20 2.31.1