On Fri, Mar 16, 2018 at 11:36 AM, <jeffm@xxxxxxxx> wrote:
> From: Jeff Mahoney <jeffm@xxxxxxxx>
>
> 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.
>
> ========================================================
> 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: [<ffffffffc06994fa>] __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);
> <Interrupt>
> lock(&delayed_node->mutex);
>
> *** DEADLOCK ***
>
> 2 locks held by kswapd0/50:
> #0: (shrinker_rwsem){++++..}, at: [<ffffffff811dc11f>] shrink_slab+0x7f/0x5b0
> #1: (&type->s_umount_key#30){+++++.}, at: [<ffffffff8126dec6>] 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: [<ffffffff821d8e70>] 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: [<ffffffffc0729578>] __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: [<ffffffffc0729488>] __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: [<ffffffffc072d488>] __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
>
Looks OK to me.
Reviewed-by: Liu Bo <bo.liu@xxxxxxxxxxxxxxxxx>
thanks,
liubo
> Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
> ---
> 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);
> --
> 2.15.1
>
> --
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