On Fri, Mar 16, 2018 at 11:36 AM,  <[email protected]> wrote:
> From: Jeff Mahoney <[email protected]>
>
> 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 <[email protected]>

thanks,
liubo

> Signed-off-by: Jeff Mahoney <[email protected]>
> ---
>  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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to [email protected]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to