lockdep warning on chunk_mutex/fs_reclaim/delayed_node->mutex
btrfs/073 [16:46:49][ 4389.528850] run fstests btrfs/073 at 2020-05-11 16:46:49
[ 4394.208553] BTRFS info (device vdb): disk space caching is enabled
[ 4394.208698] BTRFS info (device vdb): scrub: finished on devid 4 with status: 0
[ 4394.212495] BTRFS info (device vdb): scrub: finished on devid 5 with status: 0
[ 4394.276890] BTRFS info (device vdb): scrub: finished on devid 6 with status: 0
[ 4394.408713] BTRFS info (device vdb): scrub: finished on devid 1 with status: 0
[ 4394.408814] BTRFS info (device vdb): use zlib compression, level 3
[ 4394.413630] BTRFS info (device vdb): disk space caching is enabled
[ 4394.452197] BTRFS info (device vdb): scrub: started on devid 5
[ 4394.452587] BTRFS info (device vdb): scrub: started on devid 4
[ 4394.462946] BTRFS info (device vdb): scrub: finished on devid 5 with status: 0
[ 4394.473072] BTRFS info (device vdb): scrub: started on devid 3
[ 4394.483089] BTRFS info (device vdb): scrub: started on devid 1
[ 4394.490128] BTRFS info (device vdb): scrub: started on devid 6
[ 4394.494793] BTRFS info (device vdb): scrub: started on devid 2
[ 4394.497311] BTRFS info (device vdb): scrub: finished on devid 4 with status: 0
[ 4394.530402]
[ 4394.532133] ======================================================
[ 4394.534771] WARNING: possible circular locking dependency detected
[ 4394.536949] 5.7.0-rc5-default+ #1100 Not tainted
[ 4394.538809] ------------------------------------------------------
[ 4394.541508] fsstress/15173 is trying to acquire lock:
[ 4394.542204] BTRFS info (device vdb): scrub: finished on devid 2 with status: 0
[ 4394.544236] ffff9a5c7153c980 (&fs_info->chunk_mutex){+.+.}-{3:3}, at: btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.544274]
[ 4394.544274] but task is already holding lock:
[ 4394.553183] ffff9a5c74857458 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_commit_inode_delayed_items+0x58/0x510 [btrfs]
[ 4394.557542]
[ 4394.557542] which lock already depends on the new lock.
[ 4394.557542]
[ 4394.561420]
[ 4394.561420] the existing dependency chain (in reverse order) is:
[ 4394.565023]
[ 4394.565023] -> #2 (&delayed_node->mutex){+.+.}-{3:3}:
[ 4394.567738] __lock_acquire+0x581/0xae0
[ 4394.568965] lock_acquire+0xa3/0x400
[ 4394.570307] __mutex_lock+0xa0/0xaf0
[ 4394.571983] __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
[ 4394.574411] btrfs_evict_inode+0x3b7/0x550 [btrfs]
[ 4394.576443] evict+0xd6/0x1c0
[ 4394.578185] dispose_list+0x48/0x70
[ 4394.579583] prune_icache_sb+0x54/0x80
[ 4394.581163] super_cache_scan+0x121/0x1a0
[ 4394.583106] do_shrink_slab+0x175/0x420
[ 4394.585205] shrink_slab+0xb1/0x2e0
[ 4394.587248] shrink_node+0x162/0x5c0
[ 4394.588947] balance_pgdat+0x324/0x750
[ 4394.590764] kswapd+0x236/0x530
[ 4394.592227] kthread+0x130/0x150
[ 4394.593454] ret_from_fork+0x24/0x30
[ 4394.594737]
[ 4394.594737] -> #1 (fs_reclaim){+.+.}-{0:0}:
[ 4394.597285] __lock_acquire+0x581/0xae0
[ 4394.598822] lock_acquire+0xa3/0x400
[ 4394.600814] fs_reclaim_acquire.part.0+0x25/0x30
[ 4394.602349] __kmalloc_track_caller+0x4a/0x370
[ 4394.603671] kstrdup+0x2e/0x60
[ 4394.604706] __kernfs_new_node.constprop.0+0x41/0x1c0
[ 4394.605874] kernfs_new_node+0x25/0x50
[ 4394.606856] kernfs_create_link+0x34/0xa0
[ 4394.607871] sysfs_do_create_link_sd+0x5e/0xd0
[ 4394.609063] btrfs_sysfs_add_devices_dir+0x65/0x100 [btrfs]
[ 4394.610879] btrfs_init_new_device+0x44b/0x1300 [btrfs]
[ 4394.612519] btrfs_ioctl+0xc3c/0x2590 [btrfs]
[ 4394.614139] ksys_ioctl+0x68/0xa0
[ 4394.615490] __x64_sys_ioctl+0x16/0x20
[ 4394.616988] do_syscall_64+0x50/0x210
[ 4394.618235] entry_SYSCALL_64_after_hwframe+0x49/0xb3
[ 4394.619541]
[ 4394.619541] -> #0 (&fs_info->chunk_mutex){+.+.}-{3:3}:
[ 4394.621414] check_prev_add+0x98/0xa20
[ 4394.622859] validate_chain+0xa6c/0x29e0
[ 4394.623992] __lock_acquire+0x581/0xae0
[ 4394.625165] lock_acquire+0xa3/0x400
[ 4394.626628] __mutex_lock+0xa0/0xaf0
[ 4394.627990] btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.629365] find_free_extent+0xb47/0xfb0 [btrfs]
[ 4394.630642] btrfs_reserve_extent+0x9b/0x180 [btrfs]
[ 4394.631977] btrfs_alloc_tree_block+0xc1/0x350 [btrfs]
[ 4394.633273] alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
[ 4394.635117] __btrfs_cow_block+0x143/0x7a0 [btrfs]
[ 4394.636408] btrfs_cow_block+0x15f/0x310 [btrfs]
[ 4394.638120] btrfs_search_slot+0x937/0xf70 [btrfs]
[ 4394.639746] btrfs_insert_empty_items+0x64/0xc0 [btrfs]
[ 4394.641636] __btrfs_commit_inode_delayed_items+0xaf/0x510 [btrfs]
[ 4394.643733] __btrfs_run_delayed_items+0x8e/0x140 [btrfs]
[ 4394.645344] btrfs_commit_transaction+0x312/0xae0 [btrfs]
[ 4394.646804] btrfs_sync_file+0x345/0x490 [btrfs]
[ 4394.648369] do_fsync+0x38/0x70
[ 4394.649732] __x64_sys_fsync+0x10/0x20
[ 4394.651214] do_syscall_64+0x50/0x210
[ 4394.652691] entry_SYSCALL_64_after_hwframe+0x49/0xb3
[ 4394.654307]
[ 4394.654307] other info that might help us debug this:
[ 4394.654307]
[ 4394.666340] Chain exists of:
[ 4394.666340] &fs_info->chunk_mutex --> fs_reclaim --> &delayed_node->mutex
[ 4394.666340]
[ 4394.669883] Possible unsafe locking scenario:
[ 4394.669883]
[ 4394.671702] CPU0 CPU1
[ 4394.672939] ---- ----
[ 4394.674445] lock(&delayed_node->mutex);
[ 4394.675745] lock(fs_reclaim);
[ 4394.677590] lock(&delayed_node->mutex);
[ 4394.679685] lock(&fs_info->chunk_mutex);
[ 4394.681219]
[ 4394.681219] *** DEADLOCK ***
[ 4394.681219]
[ 4394.683928] 2 locks held by fsstress/15173:
[ 4394.685460] #0: ffff9a5c72851698 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x409/0x5e0 [btrfs]
[ 4394.688402] #1: ffff9a5c74857458 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_commit_inode_delayed_items+0x58/0x510 [btrfs]
[ 4394.691958]
[ 4394.691958] stack backtrace:
[ 4394.693535] CPU: 3 PID: 15173 Comm: fsstress Not tainted 5.7.0-rc5-default+ #1100
[ 4394.695708] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
[ 4394.698798] Call Trace:
[ 4394.699882] dump_stack+0x71/0xa0
[ 4394.701212] check_noncircular+0x16f/0x190
[ 4394.702598] check_prev_add+0x98/0xa20
[ 4394.703937] validate_chain+0xa6c/0x29e0
[ 4394.705332] ? btrfs_sync_file+0x344/0x490 [btrfs]
[ 4394.706947] ? btrfs_sync_file+0x344/0x490 [btrfs]
[ 4394.708510] __lock_acquire+0x581/0xae0
[ 4394.709719] lock_acquire+0xa3/0x400
[ 4394.710743] ? btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.711960] __mutex_lock+0xa0/0xaf0
[ 4394.712969] ? btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.714301] ? lock_acquire+0xa3/0x400
[ 4394.715359] ? btrfs_chunk_alloc+0x60/0x3e0 [btrfs]
[ 4394.716540] ? btrfs_chunk_alloc+0x115/0x3e0 [btrfs]
[ 4394.718071] ? btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.719301] ? sched_clock+0x5/0x10
[ 4394.720295] ? sched_clock_cpu+0x15/0x130
[ 4394.721589] ? btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.723112] btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
[ 4394.724618] find_free_extent+0xb47/0xfb0 [btrfs]
[ 4394.726111] ? kvm_sched_clock_read+0x14/0x30
[ 4394.727509] ? sched_clock+0x5/0x10
[ 4394.728768] btrfs_reserve_extent+0x9b/0x180 [btrfs]
[ 4394.730391] btrfs_alloc_tree_block+0xc1/0x350 [btrfs]
[ 4394.732123] alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
[ 4394.733863] __btrfs_cow_block+0x143/0x7a0 [btrfs]
[ 4394.735463] btrfs_cow_block+0x15f/0x310 [btrfs]
[ 4394.736755] btrfs_search_slot+0x937/0xf70 [btrfs]
[ 4394.738465] btrfs_insert_empty_items+0x64/0xc0 [btrfs]
[ 4394.740230] __btrfs_commit_inode_delayed_items+0xaf/0x510 [btrfs]
[ 4394.742450] __btrfs_run_delayed_items+0x8e/0x140 [btrfs]
[ 4394.743916] btrfs_commit_transaction+0x312/0xae0 [btrfs]
[ 4394.745409] btrfs_sync_file+0x345/0x490 [btrfs]
[ 4394.746958] do_fsync+0x38/0x70
[ 4394.747900] __x64_sys_fsync+0x10/0x20
[ 4394.749010] do_syscall_64+0x50/0x210
[ 4394.750312] entry_SYSCALL_64_after_hwframe+0x49/0xb3
[ 4394.751628] RIP: 0033:0x7f139f754683
[ 4394.758709] RSP: 002b:00007ffc208bf158 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
[ 4394.761394] RAX: ffffffffffffffda RBX: 0000000000000032 RCX: 00007f139f754683
[ 4394.763330] RDX: 00007ffc208bf0c0 RSI: 00007ffc208bf0c0 RDI: 0000000000000003
[ 4394.764955] RBP: 0000000000000003 R08: 0000000000000001 R09: 00007ffc208bf16c
[ 4394.766611] R10: 000000000040108e R11: 0000000000000246 R12: 0000000000000017
[ 4394.768113] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
