From patchwork Wed Nov 23 17:47:15 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 9444045 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3BB3C60778 for ; Wed, 23 Nov 2016 17:47:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E244203C0 for ; Wed, 23 Nov 2016 17:47:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 42D1C27C7A; Wed, 23 Nov 2016 17:47:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A473203C0 for ; Wed, 23 Nov 2016 17:47:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938808AbcKWRr0 (ORCPT ); Wed, 23 Nov 2016 12:47:26 -0500 Received: from mail.kernel.org ([198.145.29.136]:54788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964816AbcKWRrX (ORCPT ); Wed, 23 Nov 2016 12:47:23 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 642DF203F1; Wed, 23 Nov 2016 17:47:21 +0000 (UTC) Received: from debian3.lan (bl12-226-64.dsl.telepac.pt [85.245.226.64]) (using TLSv1.2 with cipher AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B410203ED; Wed, 23 Nov 2016 17:47:19 +0000 (UTC) From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Cc: bo.li.liu@oracle.com Subject: [PATCH] Btrfs: fix emptiness check for dirtied extent buffers at check_leaf() Date: Wed, 23 Nov 2016 17:47:15 +0000 Message-Id: <1479923235-18968-1-git-send-email-fdmanana@kernel.org> X-Mailer: git-send-email 2.7.0.rc3 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Filipe Manana We can not simply use the owner field from an extent buffer's header to get the id of the respective tree when the extent buffer is from a relocation tree. When we create the root for a relocation tree we leave (on purpose) the owner field with the same value as the subvolume's tree root (we do this at ctree.c:btrfs_copy_root()). So we must ignore extent buffers from relocation trees, which have the BTRFS_HEADER_FLAG_RELOC flag set, because otherwise we will always consider the extent buffer as not being the root of the tree (the root of original subvolume tree is always different from the root of the respective relocation tree). This lead to assertion failures when running with the integrity checker enabled (CONFIG_BTRFS_FS_CHECK_INTEGRITY=y) such as the following: [ 643.393409] BTRFS critical (device sdg): corrupt leaf, non-root leaf's nritems is 0: block=38506496, root=260, slot=0 [ 643.397609] BTRFS info (device sdg): leaf 38506496 total ptrs 0 free space 3995 [ 643.407075] assertion failed: 0, file: fs/btrfs/disk-io.c, line: 4078 [ 643.408425] ------------[ cut here ]------------ [ 643.409112] kernel BUG at fs/btrfs/ctree.h:3419! [ 643.409773] invalid opcode: 0000 [#1] PREEMPT SMP [ 643.410447] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq ppdev psmouse acpi_cpufreq parport_pc evdev parport tpm_tis tpm_tis_core pcspkr serio_raw i2c_piix4 sg tpm i2c_core button processor loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring scsi_mod virtio e1000 floppy [ 643.414356] CPU: 11 PID: 32726 Comm: btrfs Not tainted 4.8.0-rc8-btrfs-next-35+ #1 [ 643.414356] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 643.414356] task: ffff880145e95b00 task.stack: ffff88014826c000 [ 643.414356] RIP: 0010:[] [] assfail.constprop.41+0x1c/0x1e [btrfs] [ 643.414356] RSP: 0018:ffff88014826fa28 EFLAGS: 00010292 [ 643.414356] RAX: 0000000000000039 RBX: ffff88014e2d7c38 RCX: 0000000000000001 [ 643.414356] RDX: ffff88023f4d2f58 RSI: ffffffff81806c63 RDI: 00000000ffffffff [ 643.414356] RBP: ffff88014826fa28 R08: 0000000000000001 R09: 0000000000000000 [ 643.414356] R10: ffff88014826f918 R11: ffffffff82f3c5ed R12: ffff880172910000 [ 643.414356] R13: ffff880233992230 R14: ffff8801a68a3310 R15: fffffffffffffff8 [ 643.414356] FS: 00007f9ca305e8c0(0000) GS:ffff88023f4c0000(0000) knlGS:0000000000000000 [ 643.414356] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 643.414356] CR2: 00007f9ca3071000 CR3: 000000015d01b000 CR4: 00000000000006e0 [ 643.414356] Stack: [ 643.414356] ffff88014826fa50 ffffffffa02d655a 000000000000000a ffff88014e2d7c38 [ 643.414356] 0000000000000000 ffff88014826faa8 ffffffffa02b72f3 ffff88014826fab8 [ 643.414356] 00ffffffa03228e4 0000000000000000 0000000000000000 ffff8801bbd4e000 [ 643.414356] Call Trace: [ 643.414356] [] btrfs_mark_buffer_dirty+0xdf/0xe5 [btrfs] [ 643.414356] [] btrfs_copy_root+0x18a/0x1d1 [btrfs] [ 643.414356] [] create_reloc_root+0x72/0x1ba [btrfs] [ 643.414356] [] btrfs_init_reloc_root+0x7b/0xa7 [btrfs] [ 643.414356] [] record_root_in_trans+0xdf/0xed [btrfs] [ 643.414356] [] btrfs_record_root_in_trans+0x50/0x6a [btrfs] [ 643.414356] [] create_subvol+0x472/0x773 [btrfs] [ 643.414356] [] btrfs_mksubvol+0x3da/0x463 [btrfs] [ 643.414356] [] ? btrfs_mksubvol+0x3da/0x463 [btrfs] [ 643.414356] [] ? preempt_count_add+0x65/0x68 [ 643.414356] [] ? __mnt_want_write+0x62/0x77 [ 643.414356] [] btrfs_ioctl_snap_create_transid+0xce/0x187 [btrfs] [ 643.414356] [] btrfs_ioctl_snap_create+0x67/0x81 [btrfs] [ 643.414356] [] btrfs_ioctl+0x508/0x20dd [btrfs] [ 643.414356] [] ? __this_cpu_preempt_check+0x13/0x15 [ 643.414356] [] ? handle_mm_fault+0x976/0x9ab [ 643.414356] [] ? arch_local_irq_save+0x9/0xc [ 643.414356] [] vfs_ioctl+0x18/0x34 [ 643.414356] [] do_vfs_ioctl+0x581/0x600 [ 643.414356] [] ? entry_SYSCALL_64_fastpath+0x5/0xa8 [ 643.414356] [] ? trace_hardirqs_on_caller+0x17b/0x197 [ 643.414356] [] SyS_ioctl+0x57/0x79 [ 643.414356] [] entry_SYSCALL_64_fastpath+0x18/0xa8 [ 643.414356] [] ? trace_hardirqs_off_caller+0x3f/0xaa [ 643.414356] Code: 89 83 88 00 00 00 31 c0 5b 41 5c 41 5d 5d c3 55 89 f1 48 c7 c2 98 bc 35 a0 48 89 fe 48 c7 c7 05 be 35 a0 48 89 e5 e8 13 46 dd e0 <0f> 0b 55 89 f1 48 c7 c2 9f d3 35 a0 48 89 fe 48 c7 c7 7a d5 35 [ 643.414356] RIP [] assfail.constprop.41+0x1c/0x1e [btrfs] [ 643.414356] RSP [ 643.468267] ---[ end trace 6a1b3fb1a9d7d6e3 ]--- This can be easily reproduced by running xfstests with the integrity checker enabled. Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item) Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Filipe Manana Reviewed-by: Liu Bo --- fs/btrfs/disk-io.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index c4e673a..1cd3257 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -559,7 +559,15 @@ static noinline int check_leaf(struct btrfs_root *root, u32 nritems = btrfs_header_nritems(leaf); int slot; - if (nritems == 0) { + /* + * Extent buffers from a relocation tree have a owner field that + * corresponds to the subvolume tree they are based on. So just from an + * extent buffer alone we can not find out what is the id of the + * corresponding subvolume tree, so we can not figure out if the extent + * buffer corresponds to the root of the relocation tree or not. So skip + * this check for relocation trees. + */ + if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) { struct btrfs_root *check_root; key.objectid = btrfs_header_owner(leaf); @@ -587,6 +595,9 @@ static noinline int check_leaf(struct btrfs_root *root, return 0; } + if (nritems == 0) + return 0; + /* Check the 0 item */ if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)) {