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SubjectRe: btrfs: lock inversion between delayed_node->mutex and found->groups_sem
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On 3/17/14, 9:05 AM, David Sterba wrote:
> On Fri, Mar 14, 2014 at 08:12:16PM -0400, Sasha Levin wrote:
>> While fuzzing with trinity inside a KVM tools guest running the
>> latest -next kernel I've stumbled on the following:
>>
>> [ 788.458756] CPU0 CPU1 [ 788.459188]
>> ---- ---- [ 788.459625]
>> lock(&found->groups_sem); [ 788.460041]
>> local_irq_disable(); [ 788.460041]
>> lock(&delayed_node->mutex); [ 788.460041]
>> lock(&found->groups_sem); [ 788.460041] <Interrupt> [
>> 788.460041] lock(&delayed_node->mutex); [ 788.460041] [
>> 788.460041] *** DEADLOCK *** [ 788.460041] [ 788.460041] 2
>> locks held by kswapd3/4199:
>
> I've once (3.14-rc5) seen the same warning also caused by
> xfstests/generic/224

I think this is from my sysfs patches. We call kobject_add while
holding the group_sem. kobject_add ultimately allocates with
GFP_KERNEL, so it can enter reclaim. This particular case isn't
dangerous, but it could hit while hot-adding a device. The fix should
be pretty simple.

- -Jeff

> 2 locks held by 224/31203: #0: (shrinker_rwsem){++++..}, at:
> [<ffffffff8113be6d>] shrink_slab+0x3d/0x110 #1:
> (&type->s_umount_key#32){++++++}, at: [<ffffffff8117cd84>]
> grab_super_passive+0x44/0x90
>
> the shortest dependencies between 2nd lock and 1st lock: ->
> (&found->groups_sem){+++++.} ops: 405561 { HARDIRQ-ON-W at:
> [<ffffffff810af476>] __lock_acquire+0x7f6/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a01d3c>]
> down_write+0x5c/0xc0 [<ffffffffa001f6a6>]
> __link_block_group+0x46/0x130 [btrfs] [<ffffffffa0023411>]
> btrfs_read_block_groups+0x341/0x690 [btrfs] [<ffffffffa0031c50>]
> open_ctree+0x1880/0x2310 [btrfs] [<ffffffffa00065db>]
> btrfs_mount+0x55b/0x860 [btrfs] [<ffffffff8117d6f0>]
> mount_fs+0x20/0xe0 [<ffffffff81199ab6>] vfs_kern_mount+0x76/0x160
> [<ffffffff8119c25d>] do_mount+0x31d/0x970 [<ffffffff8119cc30>]
> SyS_mount+0x90/0xe0 [<ffffffff81a0ca92>]
> system_call_fastpath+0x16/0x1b HARDIRQ-ON-R at:
> [<ffffffff810af265>] __lock_acquire+0x5e5/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a01c8c>]
> down_read+0x4c/0xa0 [<ffffffffa002da32>]
> btrfs_calc_num_tolerated_disk_barrier_failures+0x142/0x240 [btrfs]
> [<ffffffffa0031c6e>] open_ctree+0x189e/0x2310 [btrfs]
> [<ffffffffa00065db>] btrfs_mount+0x55b/0x860 [btrfs]
> [<ffffffff8117d6f0>] mount_fs+0x20/0xe0 [<ffffffff81199ab6>]
> vfs_kern_mount+0x76/0x160 [<ffffffff8119c25d>]
> do_mount+0x31d/0x970 [<ffffffff8119cc30>] SyS_mount+0x90/0xe0
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b SOFTIRQ-ON-W
> at: [<ffffffff810af4aa>] __lock_acquire+0x82a/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a01d3c>]
> down_write+0x5c/0xc0 [<ffffffffa001f6a6>]
> __link_block_group+0x46/0x130 [btrfs] [<ffffffffa0023411>]
> btrfs_read_block_groups+0x341/0x690 [btrfs] [<ffffffffa0031c50>]
> open_ctree+0x1880/0x2310 [btrfs] [<ffffffffa00065db>]
> btrfs_mount+0x55b/0x860 [btrfs] [<ffffffff8117d6f0>]
> mount_fs+0x20/0xe0 [<ffffffff81199ab6>] vfs_kern_mount+0x76/0x160
> [<ffffffff8119c25d>] do_mount+0x31d/0x970 [<ffffffff8119cc30>]
> SyS_mount+0x90/0xe0 [<ffffffff81a0ca92>]
> system_call_fastpath+0x16/0x1b SOFTIRQ-ON-R at:
> [<ffffffff810af4aa>] __lock_acquire+0x82a/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a01c8c>]
> down_read+0x4c/0xa0 [<ffffffffa002da32>]
> btrfs_calc_num_tolerated_disk_barrier_failures+0x142/0x240 [btrfs]
> [<ffffffffa0031c6e>] open_ctree+0x189e/0x2310 [btrfs]
> [<ffffffffa00065db>] btrfs_mount+0x55b/0x860 [btrfs]
> [<ffffffff8117d6f0>] mount_fs+0x20/0xe0 [<ffffffff81199ab6>]
> vfs_kern_mount+0x76/0x160 [<ffffffff8119c25d>]
> do_mount+0x31d/0x970 [<ffffffff8119cc30>] SyS_mount+0x90/0xe0
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b RECLAIM_FS-ON-W
> at: [<ffffffff810b1c6c>] mark_held_locks+0x8c/0x170
> [<ffffffff810b249a>] lockdep_trace_alloc+0x8a/0xd0
> [<ffffffff8116f807>] __kmalloc_track_caller+0x47/0x210
> [<ffffffff813cdefb>] kvasprintf+0x5b/0x90 [<ffffffff813c166a>]
> kobject_set_name_vargs+0x2a/0x70 [<ffffffff813c1ffa>]
> kobject_add+0x5a/0xb0 [<ffffffffa001f75d>]
> __link_block_group+0xfd/0x130 [btrfs] [<ffffffffa0023411>]
> btrfs_read_block_groups+0x341/0x690 [btrfs] [<ffffffffa0031c50>]
> open_ctree+0x1880/0x2310 [btrfs] [<ffffffffa00065db>]
> btrfs_mount+0x55b/0x860 [btrfs] [<ffffffff8117d6f0>]
> mount_fs+0x20/0xe0 [<ffffffff81199ab6>] vfs_kern_mount+0x76/0x160
> [<ffffffff8119c25d>] do_mount+0x31d/0x970 [<ffffffff8119cc30>]
> SyS_mount+0x90/0xe0 [<ffffffff81a0ca92>]
> system_call_fastpath+0x16/0x1b INITIAL USE at: [<ffffffff810aefd4>]
> __lock_acquire+0x354/0x1fb0 [<ffffffff810b12e2>]
> lock_acquire+0x92/0x120 [<ffffffff81a01d3c>] down_write+0x5c/0xc0
> [<ffffffffa001f6a6>] __link_block_group+0x46/0x130 [btrfs]
> [<ffffffffa0023411>] btrfs_read_block_groups+0x341/0x690 [btrfs]
> [<ffffffffa0031c50>] open_ctree+0x1880/0x2310 [btrfs]
> [<ffffffffa00065db>] btrfs_mount+0x55b/0x860 [btrfs]
> [<ffffffff8117d6f0>] mount_fs+0x20/0xe0 [<ffffffff81199ab6>]
> vfs_kern_mount+0x76/0x160 [<ffffffff8119c25d>]
> do_mount+0x31d/0x970 [<ffffffff8119cc30>] SyS_mount+0x90/0xe0
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b } ... key
> at: [<ffffffffa00d06e0>] __key.40139+0x0/0xfffffffffffe2920
> [btrfs] ... acquired at: [<ffffffff810b12e2>]
> lock_acquire+0x92/0x120 [<ffffffff81a01c8c>] down_read+0x4c/0xa0
> [<ffffffffa001ff78>] find_free_extent+0x7e8/0xbe0 [btrfs]
> [<ffffffffa0020434>] btrfs_reserve_extent+0xa4/0x130 [btrfs]
> [<ffffffffa0021903>] btrfs_alloc_free_block+0x103/0x4c0 [btrfs]
> [<ffffffffa000beb4>] __btrfs_cow_block+0x124/0x550 [btrfs]
> [<ffffffffa000c4ab>] btrfs_cow_block+0x12b/0x1e0 [btrfs]
> [<ffffffffa0010429>] btrfs_search_slot+0x1d9/0xa00 [btrfs]
> [<ffffffffa00123de>] btrfs_insert_empty_items+0x7e/0xe0 [btrfs]
> [<ffffffffa008a7a4>] btrfs_insert_delayed_items+0x84/0x460 [btrfs]
> [<ffffffffa008b299>] __btrfs_run_delayed_items+0xd9/0x1f0 [btrfs]
> [<ffffffffa008b7a3>] btrfs_run_delayed_items+0x13/0x20 [btrfs]
> [<ffffffffa0034e6e>] btrfs_commit_transaction+0x3ae/0xa30 [btrfs]
> [<ffffffffa006ae72>] btrfs_mksubvol+0x3a2/0x3b0 [btrfs]
> [<ffffffffa006b036>] btrfs_ioctl_snap_create_transid+0x1b6/0x1c0
> [btrfs] [<ffffffffa006b1be>] btrfs_ioctl_snap_create_v2+0xfe/0x140
> [btrfs] [<ffffffffa006d1d2>] btrfs_ioctl+0x652/0x1940 [btrfs]
> [<ffffffff8118c0a1>] do_vfs_ioctl+0x91/0x560 [<ffffffff8118c5c7>]
> SyS_ioctl+0x57/0x90 [<ffffffff81a0ca92>]
> system_call_fastpath+0x16/0x1b
>
> -> (&delayed_node->mutex){+.+.-.} ops: 8191147 { HARDIRQ-ON-W at:
> [<ffffffff810af476>] __lock_acquire+0x7f6/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a00c4e>]
> mutex_lock_nested+0x6e/0x3a0 [<ffffffffa008c5c9>]
> btrfs_delayed_update_inode+0x49/0x670 [btrfs] [<ffffffffa003b76a>]
> btrfs_update_inode+0x6a/0x100 [btrfs] [<ffffffffa0043e8e>]
> btrfs_create+0x16e/0x220 [btrfs] [<ffffffff81188979>]
> vfs_create+0x89/0xc0 [<ffffffff81189144>] do_last+0x794/0xd50
> [<ffffffff811897c7>] path_openat+0xc7/0x620 [<ffffffff8118a1da>]
> do_filp_open+0x4a/0xa0 [<ffffffff8117883e>]
> do_sys_open+0x11e/0x230 [<ffffffff8117896e>] SyS_open+0x1e/0x20
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b SOFTIRQ-ON-W
> at: [<ffffffff810af4aa>] __lock_acquire+0x82a/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a00c4e>]
> mutex_lock_nested+0x6e/0x3a0 [<ffffffffa008c5c9>]
> btrfs_delayed_update_inode+0x49/0x670 [btrfs] [<ffffffffa003b76a>]
> btrfs_update_inode+0x6a/0x100 [btrfs] [<ffffffffa0043e8e>]
> btrfs_create+0x16e/0x220 [btrfs] [<ffffffff81188979>]
> vfs_create+0x89/0xc0 [<ffffffff81189144>] do_last+0x794/0xd50
> [<ffffffff811897c7>] path_openat+0xc7/0x620 [<ffffffff8118a1da>]
> do_filp_open+0x4a/0xa0 [<ffffffff8117883e>]
> do_sys_open+0x11e/0x230 [<ffffffff8117896e>] SyS_open+0x1e/0x20
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b IN-RECLAIM_FS-W
> at: [<ffffffff810af2ec>] __lock_acquire+0x66c/0x1fb0
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffff81a00c4e>]
> mutex_lock_nested+0x6e/0x3a0 [<ffffffffa0089dff>]
> __btrfs_release_delayed_node+0x4f/0x220 [btrfs]
> [<ffffffffa008bac4>] btrfs_remove_delayed_node+0x24/0x30 [btrfs]
> [<ffffffffa0040c97>] btrfs_evict_inode+0x2a7/0x550 [btrfs]
> [<ffffffff81195188>] evict+0xb8/0x1c0 [<ffffffff811952df>]
> dispose_list+0x4f/0x60 [<ffffffff811963dc>]
> prune_icache_sb+0x4c/0x60 [<ffffffff8117d006>]
> super_cache_scan+0x126/0x190 [<ffffffff8113a1fe>]
> shrink_slab_node+0x14e/0x2c0 [<ffffffff8113bea8>]
> shrink_slab+0x78/0x110 [<ffffffff8113f1bd>]
> do_try_to_free_pages+0x24d/0x410 [<ffffffff8113f554>]
> try_to_free_pages+0xe4/0x190 [<ffffffff8113235b>]
> __alloc_pages_nodemask+0x68b/0xa60 [<ffffffff8116edac>]
> cache_alloc_refill+0x40c/0x7b0 [<ffffffff8116e98f>]
> kmem_cache_alloc+0x1ef/0x200 [<ffffffff8105efae>]
> copy_process+0x13e/0x1910 [<ffffffff810608a5>] do_fork+0x65/0x300
> [<ffffffff81060bc6>] SyS_clone+0x16/0x20 [<ffffffff81a0cdb9>]
> stub_clone+0x69/0x90 INITIAL USE at: [<ffffffff810aefd4>]
> __lock_acquire+0x354/0x1fb0 [<ffffffff810b12e2>]
> lock_acquire+0x92/0x120 [<ffffffff81a00c4e>]
> mutex_lock_nested+0x6e/0x3a0 [<ffffffffa008c5c9>]
> btrfs_delayed_update_inode+0x49/0x670 [btrfs] [<ffffffffa003b76a>]
> btrfs_update_inode+0x6a/0x100 [btrfs] [<ffffffffa0043e8e>]
> btrfs_create+0x16e/0x220 [btrfs] [<ffffffff81188979>]
> vfs_create+0x89/0xc0 [<ffffffff81189144>] do_last+0x794/0xd50
> [<ffffffff811897c7>] path_openat+0xc7/0x620 [<ffffffff8118a1da>]
> do_filp_open+0x4a/0xa0 [<ffffffff8117883e>]
> do_sys_open+0x11e/0x230 [<ffffffff8117896e>] SyS_open+0x1e/0x20
> [<ffffffff81a0ca92>] system_call_fastpath+0x16/0x1b } ... key
> at: [<ffffffffa00d4648>] __key.35416+0x0/0xfffffffffffde9b8
> [btrfs] ... acquired at: [<ffffffff810add8a>]
> check_usage_forwards+0xaa/0x120 [<ffffffff810ae9f9>]
> mark_lock+0x1a9/0x430 [<ffffffff810af2ec>]
> __lock_acquire+0x66c/0x1fb0 [<ffffffff810b12e2>]
> lock_acquire+0x92/0x120 [<ffffffff81a00c4e>]
> mutex_lock_nested+0x6e/0x3a0 [<ffffffffa0089dff>]
> __btrfs_release_delayed_node+0x4f/0x220 [btrfs]
> [<ffffffffa008bac4>] btrfs_remove_delayed_node+0x24/0x30 [btrfs]
> [<ffffffffa0040c97>] btrfs_evict_inode+0x2a7/0x550 [btrfs]
> [<ffffffff81195188>] evict+0xb8/0x1c0 [<ffffffff811952df>]
> dispose_list+0x4f/0x60 [<ffffffff811963dc>]
> prune_icache_sb+0x4c/0x60 [<ffffffff8117d006>]
> super_cache_scan+0x126/0x190 [<ffffffff8113a1fe>]
> shrink_slab_node+0x14e/0x2c0 [<ffffffff8113bea8>]
> shrink_slab+0x78/0x110 [<ffffffff8113f1bd>]
> do_try_to_free_pages+0x24d/0x410 [<ffffffff8113f554>]
> try_to_free_pages+0xe4/0x190 [<ffffffff8113235b>]
> __alloc_pages_nodemask+0x68b/0xa60 [<ffffffff8116edac>]
> cache_alloc_refill+0x40c/0x7b0 [<ffffffff8116e98f>]
> kmem_cache_alloc+0x1ef/0x200 [<ffffffff8105efae>]
> copy_process+0x13e/0x1910 [<ffffffff810608a5>] do_fork+0x65/0x300
> [<ffffffff81060bc6>] SyS_clone+0x16/0x20 [<ffffffff81a0cdb9>]
> stub_clone+0x69/0x90
>
>
> stack backtrace: CPU: 1 PID: 31203 Comm: 224 Tainted: G W
> 3.14.0-rc5-default #121 Hardware name: Intel Corporation Santa Rosa
> platform/Matanzas, BIOS TSRSCRB1.86C.0047.B00.0610170821 10/17/06
> ffffffff82c37220 ffff88003faa9460 ffffffff819fd463
> 0000000000000002 ffffffff82c37220 ffff88003faa94b0 ffffffff810adc97
> ffff88003faa9500 ffffffff81f16ba4 ffff88003faa94cc ffff88003faa5730
> ffff88003faa94c0 Call Trace: [<ffffffff819fd463>]
> dump_stack+0x51/0x6e [<ffffffff810adc97>]
> print_irq_inversion_bug+0x1c7/0x210 [<ffffffff810add8a>]
> check_usage_forwards+0xaa/0x120 [<ffffffff810adce0>] ?
> print_irq_inversion_bug+0x210/0x210 [<ffffffff810ae9f9>]
> mark_lock+0x1a9/0x430 [<ffffffff810af2ec>]
> __lock_acquire+0x66c/0x1fb0 [<ffffffff810adce0>] ?
> print_irq_inversion_bug+0x210/0x210 [<ffffffff810ae4cf>] ?
> check_irq_usage+0x9f/0xf0 [<ffffffff810b002b>] ?
> __lock_acquire+0x13ab/0x1fb0 [<ffffffff810ab11d>] ?
> trace_hardirqs_off+0xd/0x10 [<ffffffffa0089dff>] ?
> __btrfs_release_delayed_node+0x4f/0x220 [btrfs]
> [<ffffffff810b12e2>] lock_acquire+0x92/0x120 [<ffffffffa0089dff>] ?
> __btrfs_release_delayed_node+0x4f/0x220 [btrfs]
> [<ffffffff81a00c4e>] mutex_lock_nested+0x6e/0x3a0
> [<ffffffffa0089dff>] ? __btrfs_release_delayed_node+0x4f/0x220
> [btrfs] [<ffffffff8109a138>] ? sched_clock_cpu+0xa8/0xd0
> [<ffffffffa0089dff>] ? __btrfs_release_delayed_node+0x4f/0x220
> [btrfs] [<ffffffff810ab62d>] ? lock_release_holdtime+0x3d/0x1c0
> [<ffffffffa0089dff>] __btrfs_release_delayed_node+0x4f/0x220
> [btrfs] [<ffffffffa008bac4>] btrfs_remove_delayed_node+0x24/0x30
> [btrfs] [<ffffffffa0040c97>] btrfs_evict_inode+0x2a7/0x550 [btrfs]
> [<ffffffff81a03c6b>] ? _raw_spin_unlock+0x2b/0x40
> [<ffffffff81195188>] evict+0xb8/0x1c0 [<ffffffff81195ed0>] ?
> insert_inode_locked+0x1a0/0x1a0 [<ffffffff811952df>]
> dispose_list+0x4f/0x60 [<ffffffff811963dc>]
> prune_icache_sb+0x4c/0x60 [<ffffffff8117d006>]
> super_cache_scan+0x126/0x190 [<ffffffff8113a1fe>]
> shrink_slab_node+0x14e/0x2c0 [<ffffffff8109a176>] ?
> local_clock+0x16/0x30 [<ffffffff8113bea8>] shrink_slab+0x78/0x110
> [<ffffffff8113f1bd>] do_try_to_free_pages+0x24d/0x410
> [<ffffffff8113f554>] try_to_free_pages+0xe4/0x190
> [<ffffffff8113235b>] __alloc_pages_nodemask+0x68b/0xa60
> [<ffffffff8116ed6e>] ? cache_alloc_refill+0x3ce/0x7b0
> [<ffffffff8116edac>] cache_alloc_refill+0x40c/0x7b0
> [<ffffffff8105efae>] ? copy_process+0x13e/0x1910
> [<ffffffff8116e98f>] kmem_cache_alloc+0x1ef/0x200
> [<ffffffff8105efae>] copy_process+0x13e/0x1910 [<ffffffff8109a138>]
> ? sched_clock_cpu+0xa8/0xd0 [<ffffffff8109a176>] ?
> local_clock+0x16/0x30 [<ffffffff810ab62d>] ?
> lock_release_holdtime+0x3d/0x1c0 [<ffffffff810b0fc5>] ?
> lock_release_non_nested+0x395/0x3e0 [<ffffffff8114fd86>] ?
> might_fault+0x66/0xc0 [<ffffffff810608a5>] do_fork+0x65/0x300
> [<ffffffff8114fd86>] ? might_fault+0x66/0xc0 [<ffffffff81a0cab7>] ?
> sysret_check+0x1b/0x56 [<ffffffff81060bc6>] SyS_clone+0x16/0x20
> [<ffffffff81a0cdb9>] stub_clone+0x69/0x90 [<ffffffff81a0ca92>] ?
> system_call_fastpath+0x16/0x1b -- To unsubscribe from this list:
> send the line "unsubscribe linux-btrfs" in the body of a message to
> majordomo@vger.kernel.org More majordomo info at
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>


- --
Jeff Mahoney
SUSE Labs
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