From patchwork Fri Mar 16 18:36:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Mahoney X-Patchwork-Id: 10289825 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 28A40601BE for ; Fri, 16 Mar 2018 18:36:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15A3A29070 for ; Fri, 16 Mar 2018 18:36:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 09FEC29073; Fri, 16 Mar 2018 18:36:38 +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 E62B229070 for ; Fri, 16 Mar 2018 18:36:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751445AbeCPSge (ORCPT ); Fri, 16 Mar 2018 14:36:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:33689 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbeCPSgc (ORCPT ); Fri, 16 Mar 2018 14:36:32 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 1D38AAEF0 for ; Fri, 16 Mar 2018 18:36:31 +0000 (UTC) Received: from starscream.home.jeffm.io (starscream-1.home.jeffm.io [192.168.1.254]) by mail.home.jeffm.io (Postfix) with ESMTPS id AF99181AD3C1; Fri, 16 Mar 2018 14:36:26 -0400 (EDT) Received: by starscream.home.jeffm.io (Postfix, from userid 1000) id 5B18F8075E; Fri, 16 Mar 2018 14:36:29 -0400 (EDT) From: jeffm@suse.com To: linux-btrfs@vger.kernel.org Cc: Jeff Mahoney Subject: [PATCH] btrfs: fix lockdep splat in btrfs_alloc_subvolume_writers Date: Fri, 16 Mar 2018 14:36:27 -0400 Message-Id: <20180316183627.15476-1-jeffm@suse.com> X-Mailer: git-send-email 2.15.1 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: Jeff Mahoney While running btrfs/011, I hit the following lockdep splat. This is the important bit: pcpu_alloc+0x1ac/0x5e0 __percpu_counter_init+0x4e/0xb0 btrfs_init_fs_root+0x99/0x1c0 [btrfs] btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs] resolve_indirect_refs+0x130/0x830 [btrfs] find_parent_nodes+0x69e/0xff0 [btrfs] btrfs_find_all_roots_safe+0xa0/0x110 [btrfs] btrfs_find_all_roots+0x50/0x70 [btrfs] btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs] btrfs_commit_transaction+0x3ce/0x9b0 [btrfs] The percpu_counter_init call in btrfs_alloc_subvolume_writers uses GFP_KERNEL, which we can't do during transaction commit. This switches it to GFP_NOFS. Reviewed-by: Liu Bo ======================================================== WARNING: possible irq lock inversion dependency detected 4.12.14-kvmsmall #8 Tainted: G W -------------------------------------------------------- kswapd0/50 just changed the state of lock: (&delayed_node->mutex){+.+.-.}, at: [] __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] but this lock took another, RECLAIM_FS-unsafe lock in the past: (pcpu_alloc_mutex){+.+.+.} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &delayed_node->mutex --> &found->groups_sem --> pcpu_alloc_mutex Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(pcpu_alloc_mutex); local_irq_disable(); lock(&delayed_node->mutex); lock(&found->groups_sem); lock(&delayed_node->mutex); *** DEADLOCK *** 2 locks held by kswapd0/50: #0: (shrinker_rwsem){++++..}, at: [] shrink_slab+0x7f/0x5b0 #1: (&type->s_umount_key#30){+++++.}, at: [] trylock_super+0x16/0x50 the shortest dependencies between 2nd lock and 1st lock: -> (pcpu_alloc_mutex){+.+.+.} ops: 4904 { HARDIRQ-ON-W at: __mutex_lock+0x4e/0x8c0 pcpu_alloc+0x1ac/0x5e0 alloc_kmem_cache_cpus.isra.70+0x25/0xa0 __do_tune_cpucache+0x2c/0x220 do_tune_cpucache+0x26/0xc0 enable_cpucache+0x6d/0xf0 kmem_cache_init_late+0x42/0x75 start_kernel+0x343/0x4cb x86_64_start_kernel+0x127/0x134 secondary_startup_64+0xa5/0xb0 SOFTIRQ-ON-W at: __mutex_lock+0x4e/0x8c0 pcpu_alloc+0x1ac/0x5e0 alloc_kmem_cache_cpus.isra.70+0x25/0xa0 __do_tune_cpucache+0x2c/0x220 do_tune_cpucache+0x26/0xc0 enable_cpucache+0x6d/0xf0 kmem_cache_init_late+0x42/0x75 start_kernel+0x343/0x4cb x86_64_start_kernel+0x127/0x134 secondary_startup_64+0xa5/0xb0 RECLAIM_FS-ON-W at: __kmalloc+0x47/0x310 pcpu_extend_area_map+0x2b/0xc0 pcpu_alloc+0x3ec/0x5e0 alloc_kmem_cache_cpus.isra.70+0x25/0xa0 __do_tune_cpucache+0x2c/0x220 do_tune_cpucache+0x26/0xc0 enable_cpucache+0x6d/0xf0 __kmem_cache_create+0x1bf/0x390 create_cache+0xba/0x1b0 kmem_cache_create+0x1f8/0x2b0 ksm_init+0x6f/0x19d do_one_initcall+0x50/0x1b0 kernel_init_freeable+0x201/0x289 kernel_init+0xa/0x100 ret_from_fork+0x3a/0x50 INITIAL USE at: __mutex_lock+0x4e/0x8c0 pcpu_alloc+0x1ac/0x5e0 alloc_kmem_cache_cpus.isra.70+0x25/0xa0 setup_cpu_cache+0x2f/0x1f0 __kmem_cache_create+0x1bf/0x390 create_boot_cache+0x8b/0xb1 kmem_cache_init+0xa1/0x19e start_kernel+0x270/0x4cb x86_64_start_kernel+0x127/0x134 secondary_startup_64+0xa5/0xb0 } ... key at: [] pcpu_alloc_mutex+0x70/0xa0 ... acquired at: pcpu_alloc+0x1ac/0x5e0 __percpu_counter_init+0x4e/0xb0 btrfs_init_fs_root+0x99/0x1c0 [btrfs] btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs] resolve_indirect_refs+0x130/0x830 [btrfs] find_parent_nodes+0x69e/0xff0 [btrfs] btrfs_find_all_roots_safe+0xa0/0x110 [btrfs] btrfs_find_all_roots+0x50/0x70 [btrfs] btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs] btrfs_commit_transaction+0x3ce/0x9b0 [btrfs] transaction_kthread+0x176/0x1b0 [btrfs] kthread+0x102/0x140 ret_from_fork+0x3a/0x50 -> (&fs_info->commit_root_sem){++++..} ops: 1566382 { HARDIRQ-ON-W at: down_write+0x3e/0xa0 cache_block_group+0x287/0x420 [btrfs] find_free_extent+0x106c/0x12d0 [btrfs] btrfs_reserve_extent+0xd8/0x170 [btrfs] cow_file_range.isra.66+0x133/0x470 [btrfs] run_delalloc_range+0x121/0x410 [btrfs] writepage_delalloc.isra.50+0xfe/0x180 [btrfs] __extent_writepage+0x19a/0x360 [btrfs] extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs] extent_writepages+0x4d/0x60 [btrfs] do_writepages+0x1a/0x70 __filemap_fdatawrite_range+0xa7/0xe0 btrfs_rename+0x5ee/0xdb0 [btrfs] vfs_rename+0x52a/0x7e0 SyS_rename+0x351/0x3b0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 HARDIRQ-ON-R at: down_read+0x35/0x90 caching_thread+0x57/0x560 [btrfs] normal_work_helper+0x1c0/0x5e0 [btrfs] process_one_work+0x1e0/0x5c0 worker_thread+0x44/0x390 kthread+0x102/0x140 ret_from_fork+0x3a/0x50 SOFTIRQ-ON-W at: down_write+0x3e/0xa0 cache_block_group+0x287/0x420 [btrfs] find_free_extent+0x106c/0x12d0 [btrfs] btrfs_reserve_extent+0xd8/0x170 [btrfs] cow_file_range.isra.66+0x133/0x470 [btrfs] run_delalloc_range+0x121/0x410 [btrfs] writepage_delalloc.isra.50+0xfe/0x180 [btrfs] __extent_writepage+0x19a/0x360 [btrfs] extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs] extent_writepages+0x4d/0x60 [btrfs] do_writepages+0x1a/0x70 __filemap_fdatawrite_range+0xa7/0xe0 btrfs_rename+0x5ee/0xdb0 [btrfs] vfs_rename+0x52a/0x7e0 SyS_rename+0x351/0x3b0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 SOFTIRQ-ON-R at: down_read+0x35/0x90 caching_thread+0x57/0x560 [btrfs] normal_work_helper+0x1c0/0x5e0 [btrfs] process_one_work+0x1e0/0x5c0 worker_thread+0x44/0x390 kthread+0x102/0x140 ret_from_fork+0x3a/0x50 INITIAL USE at: down_write+0x3e/0xa0 cache_block_group+0x287/0x420 [btrfs] find_free_extent+0x106c/0x12d0 [btrfs] btrfs_reserve_extent+0xd8/0x170 [btrfs] cow_file_range.isra.66+0x133/0x470 [btrfs] run_delalloc_range+0x121/0x410 [btrfs] writepage_delalloc.isra.50+0xfe/0x180 [btrfs] __extent_writepage+0x19a/0x360 [btrfs] extent_write_cache_pages.constprop.56+0x249/0x3e0 [btrfs] extent_writepages+0x4d/0x60 [btrfs] do_writepages+0x1a/0x70 __filemap_fdatawrite_range+0xa7/0xe0 btrfs_rename+0x5ee/0xdb0 [btrfs] vfs_rename+0x52a/0x7e0 SyS_rename+0x351/0x3b0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 } ... key at: [] __key.61970+0x0/0xfffffffffff9aa88 [btrfs] ... acquired at: cache_block_group+0x287/0x420 [btrfs] find_free_extent+0x106c/0x12d0 [btrfs] btrfs_reserve_extent+0xd8/0x170 [btrfs] btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs] btrfs_create_tree+0xbb/0x2a0 [btrfs] btrfs_create_uuid_tree+0x37/0x140 [btrfs] open_ctree+0x23c0/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> (&found->groups_sem){++++..} ops: 2134587 { HARDIRQ-ON-W at: down_write+0x3e/0xa0 __link_block_group+0x34/0x130 [btrfs] btrfs_read_block_groups+0x33d/0x7b0 [btrfs] open_ctree+0x2054/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 HARDIRQ-ON-R at: down_read+0x35/0x90 btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs] open_ctree+0x207b/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 SOFTIRQ-ON-W at: down_write+0x3e/0xa0 __link_block_group+0x34/0x130 [btrfs] btrfs_read_block_groups+0x33d/0x7b0 [btrfs] open_ctree+0x2054/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 SOFTIRQ-ON-R at: down_read+0x35/0x90 btrfs_calc_num_tolerated_disk_barrier_failures+0x113/0x1f0 [btrfs] open_ctree+0x207b/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 INITIAL USE at: down_write+0x3e/0xa0 __link_block_group+0x34/0x130 [btrfs] btrfs_read_block_groups+0x33d/0x7b0 [btrfs] open_ctree+0x2054/0x2660 [btrfs] btrfs_mount+0xd36/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 btrfs_mount+0x18c/0xf90 [btrfs] mount_fs+0x3a/0x160 vfs_kern_mount+0x66/0x150 do_mount+0x1c1/0xcc0 SyS_mount+0x7e/0xd0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 } ... key at: [] __key.59101+0x0/0xfffffffffff9ab78 [btrfs] ... acquired at: find_free_extent+0xcb4/0x12d0 [btrfs] btrfs_reserve_extent+0xd8/0x170 [btrfs] btrfs_alloc_tree_block+0x12f/0x4c0 [btrfs] __btrfs_cow_block+0x110/0x5b0 [btrfs] btrfs_cow_block+0xd7/0x290 [btrfs] btrfs_search_slot+0x1f6/0x960 [btrfs] btrfs_lookup_inode+0x2a/0x90 [btrfs] __btrfs_update_delayed_inode+0x65/0x210 [btrfs] btrfs_commit_inode_delayed_inode+0x121/0x130 [btrfs] btrfs_evict_inode+0x3fe/0x6a0 [btrfs] evict+0xc4/0x190 __dentry_kill+0xbf/0x170 dput+0x2ae/0x2f0 SyS_rename+0x2a6/0x3b0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> (&delayed_node->mutex){+.+.-.} ops: 5580204 { HARDIRQ-ON-W at: __mutex_lock+0x4e/0x8c0 btrfs_delayed_update_inode+0x46/0x6e0 [btrfs] btrfs_update_inode+0x83/0x110 [btrfs] btrfs_dirty_inode+0x62/0xe0 [btrfs] touch_atime+0x8c/0xb0 do_generic_file_read+0x818/0xb10 __vfs_read+0xdc/0x150 vfs_read+0x8a/0x130 SyS_read+0x45/0xa0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 SOFTIRQ-ON-W at: __mutex_lock+0x4e/0x8c0 btrfs_delayed_update_inode+0x46/0x6e0 [btrfs] btrfs_update_inode+0x83/0x110 [btrfs] btrfs_dirty_inode+0x62/0xe0 [btrfs] touch_atime+0x8c/0xb0 do_generic_file_read+0x818/0xb10 __vfs_read+0xdc/0x150 vfs_read+0x8a/0x130 SyS_read+0x45/0xa0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 IN-RECLAIM_FS-W at: __mutex_lock+0x4e/0x8c0 __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] btrfs_evict_inode+0x22c/0x6a0 [btrfs] evict+0xc4/0x190 dispose_list+0x35/0x50 prune_icache_sb+0x42/0x50 super_cache_scan+0x139/0x190 shrink_slab+0x262/0x5b0 shrink_node+0x2eb/0x2f0 kswapd+0x2eb/0x890 kthread+0x102/0x140 ret_from_fork+0x3a/0x50 INITIAL USE at: __mutex_lock+0x4e/0x8c0 btrfs_delayed_update_inode+0x46/0x6e0 [btrfs] btrfs_update_inode+0x83/0x110 [btrfs] btrfs_dirty_inode+0x62/0xe0 [btrfs] touch_atime+0x8c/0xb0 do_generic_file_read+0x818/0xb10 __vfs_read+0xdc/0x150 vfs_read+0x8a/0x130 SyS_read+0x45/0xa0 do_syscall_64+0x79/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 } ... key at: [] __key.56935+0x0/0xfffffffffff96b78 [btrfs] ... acquired at: __lock_acquire+0x264/0x11c0 lock_acquire+0xbd/0x1e0 __mutex_lock+0x4e/0x8c0 __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] btrfs_evict_inode+0x22c/0x6a0 [btrfs] evict+0xc4/0x190 dispose_list+0x35/0x50 prune_icache_sb+0x42/0x50 super_cache_scan+0x139/0x190 shrink_slab+0x262/0x5b0 shrink_node+0x2eb/0x2f0 kswapd+0x2eb/0x890 kthread+0x102/0x140 ret_from_fork+0x3a/0x50 stack backtrace: CPU: 1 PID: 50 Comm: kswapd0 Tainted: G W 4.12.14-kvmsmall #8 SLE15 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0x78/0xb7 print_irq_inversion_bug.part.38+0x19f/0x1aa check_usage_forwards+0x102/0x120 ? ret_from_fork+0x3a/0x50 ? check_usage_backwards+0x110/0x110 mark_lock+0x16c/0x270 __lock_acquire+0x264/0x11c0 ? pagevec_lookup_entries+0x1a/0x30 ? truncate_inode_pages_range+0x2b3/0x7f0 lock_acquire+0xbd/0x1e0 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] __mutex_lock+0x4e/0x8c0 ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] ? __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] ? btrfs_evict_inode+0x1f6/0x6a0 [btrfs] __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs] btrfs_evict_inode+0x22c/0x6a0 [btrfs] evict+0xc4/0x190 dispose_list+0x35/0x50 prune_icache_sb+0x42/0x50 super_cache_scan+0x139/0x190 shrink_slab+0x262/0x5b0 shrink_node+0x2eb/0x2f0 kswapd+0x2eb/0x890 kthread+0x102/0x140 ? mem_cgroup_shrink_node+0x2c0/0x2c0 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x3a/0x50 Signed-off-by: Jeff Mahoney --- fs/btrfs/disk-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 21f34ad0d411..eb6bb3169a9e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1108,7 +1108,7 @@ static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void) if (!writers) return ERR_PTR(-ENOMEM); - ret = percpu_counter_init(&writers->counter, 0, GFP_KERNEL); + ret = percpu_counter_init(&writers->counter, 0, GFP_NOFS); if (ret < 0) { kfree(writers); return ERR_PTR(ret);