======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Not tainted
------------------------------------------------------
syz.4.1218/10116 is trying to acquire lock:
ffff88814377ef90 (set->srcu){.+.+}-{0:0}, at: srcu_lock_sync include/linux/srcu.h:176 [inline]
ffff88814377ef90 (set->srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x9d/0x400 kernel/rcu/srcutree.c:1418

but task is already holding lock:
ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4936 [inline]
ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x34e/0x1910 block/blk-mq.c:5065

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (&q->sysfs_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       blk_mq_elv_switch_none block/blk-mq.c:4936 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
       blk_mq_update_nr_hw_queues+0x34e/0x1910 block/blk-mq.c:5065
       nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1475
       nbd_start_device_ioctl drivers/block/nbd.c:1526 [inline]
       __nbd_ioctl drivers/block/nbd.c:1601 [inline]
       nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1641
       blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #5 (&q->q_usage_counter(io)#53){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       bio_queue_enter block/blk.h:77 [inline]
       blk_mq_submit_bio+0x14e1/0x25a0 block/blk-mq.c:3091
       __submit_bio+0x2cf/0x6a0 block/blk-core.c:629
       __submit_bio_noacct_mq block/blk-core.c:716 [inline]
       submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:745
       mpage_bio_submit_read fs/mpage.c:75 [inline]
       mpage_readahead+0x630/0x780 fs/mpage.c:377
       read_pages+0x17b/0x570 mm/readahead.c:161
       page_cache_ra_unbounded+0x708/0x820 mm/readahead.c:298
       do_page_cache_ra mm/readahead.c:328 [inline]
       force_page_cache_ra mm/readahead.c:357 [inline]
       page_cache_sync_ra+0x3e2/0xb00 mm/readahead.c:585
       filemap_get_pages+0x59a/0x1fb0 mm/filemap.c:2580
       filemap_read+0x464/0x1260 mm/filemap.c:2691
       blkdev_read_iter+0x2d8/0x430 block/fops.c:795
       new_sync_read fs/read_write.c:484 [inline]
       vfs_read+0x977/0xb40 fs/read_write.c:565
       ksys_read+0x18f/0x2b0 fs/read_write.c:708
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #4 (mapping.invalidate_lock#2){.+.+}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:920 [inline]
       page_cache_ra_unbounded+0x156/0x820 mm/readahead.c:229
       do_sync_mmap_readahead+0x4a6/0x990
       filemap_fault+0x89e/0x16c0 mm/filemap.c:3447
       __do_fault+0x137/0x390 mm/memory.c:4977
       do_read_fault mm/memory.c:5392 [inline]
       do_fault mm/memory.c:5526 [inline]
       do_pte_missing mm/memory.c:4047 [inline]
       handle_pte_fault mm/memory.c:5889 [inline]
       __handle_mm_fault+0x4c44/0x70f0 mm/memory.c:6032
       handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6201
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
       raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
       copy_from_user_iter lib/iov_iter.c:55 [inline]
       iterate_ubuf include/linux/iov_iter.h:30 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
       iterate_and_advance include/linux/iov_iter.h:328 [inline]
       __copy_from_iter lib/iov_iter.c:249 [inline]
       _copy_from_iter+0x263/0x1c20 lib/iov_iter.c:260
       copy_from_iter include/linux/uio.h:228 [inline]
       copy_from_iter_full include/linux/uio.h:245 [inline]
       memcpy_from_msg include/linux/skbuff.h:4196 [inline]
       sctp_make_abort_user+0x2f3/0x9b0 net/sctp/sm_make_chunk.c:1027
       sctp_sendmsg_check_sflags+0x1b9/0x2c0 net/sctp/socket.c:1776
       sctp_sendmsg+0xc1d/0x3520 net/sctp/socket.c:1999
       sock_sendmsg_nosec net/socket.c:713 [inline]
       __sock_sendmsg+0x1a6/0x270 net/socket.c:728
       ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2568
       ___sys_sendmsg net/socket.c:2622 [inline]
       __sys_sendmmsg+0x36a/0x720 net/socket.c:2711
       __do_sys_sendmmsg net/socket.c:2738 [inline]
       __se_sys_sendmmsg net/socket.c:2735 [inline]
       __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2735
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       lock_sock_nested+0x48/0x100 net/core/sock.c:3645
       lock_sock include/net/sock.h:1624 [inline]
       inet_autobind net/ipv4/af_inet.c:178 [inline]
       inet_send_prepare net/ipv4/af_inet.c:837 [inline]
       inet_sendmsg+0x120/0x390 net/ipv4/af_inet.c:848
       sock_sendmsg_nosec net/socket.c:713 [inline]
       __sock_sendmsg+0x1a6/0x270 net/socket.c:728
       sock_sendmsg+0x134/0x200 net/socket.c:751
       __sock_xmit+0x219/0x4e0 drivers/block/nbd.c:574
       sock_xmit drivers/block/nbd.c:602 [inline]
       nbd_send_cmd+0x996/0x2110 drivers/block/nbd.c:712
       nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
       nbd_queue_rq+0xcd5/0xef0 drivers/block/nbd.c:1204
       blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
       __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309
       blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331
       blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
       blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
       __blk_flush_plug+0x420/0x500 block/blk-core.c:1214
       blk_finish_plug block/blk-core.c:1241 [inline]
       __submit_bio+0x54a/0x6a0 block/blk-core.c:643
       __submit_bio_noacct_mq block/blk-core.c:716 [inline]
       submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:745
       submit_bh fs/buffer.c:2819 [inline]
       block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
       filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2390
       do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960
       read_mapping_folio include/linux/pagemap.h:1023 [inline]
       read_part_sector+0xb3/0x260 block/partitions/core.c:722
       adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:693
       blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
       bdev_open+0x2d4/0xc50 block/bdev.c:915
       blkdev_open+0x38e/0x4e0 block/fops.c:652
       do_dentry_open+0xdee/0x1960 fs/open.c:955
       vfs_open+0x3b/0x370 fs/open.c:1085
       do_open fs/namei.c:3830 [inline]
       path_openat+0x2c81/0x3590 fs/namei.c:3989
       do_filp_open+0x27f/0x4e0 fs/namei.c:4016
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1427
       do_sys_open fs/open.c:1442 [inline]
       __do_sys_openat fs/open.c:1458 [inline]
       __se_sys_openat fs/open.c:1453 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1453
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&nsock->tx_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
       nbd_queue_rq+0x262/0xef0 drivers/block/nbd.c:1204
       blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
       __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309
       blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331
       blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
       blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
       __blk_flush_plug+0x420/0x500 block/blk-core.c:1214
       blk_finish_plug block/blk-core.c:1241 [inline]
       __submit_bio+0x54a/0x6a0 block/blk-core.c:643
       __submit_bio_noacct_mq block/blk-core.c:716 [inline]
       submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:745
       submit_bh fs/buffer.c:2819 [inline]
       block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
       filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2390
       do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960
       read_mapping_folio include/linux/pagemap.h:1023 [inline]
       read_part_sector+0xb3/0x260 block/partitions/core.c:722
       adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:693
       blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
       bdev_open+0x2d4/0xc50 block/bdev.c:915
       blkdev_open+0x38e/0x4e0 block/fops.c:652
       do_dentry_open+0xdee/0x1960 fs/open.c:955
       vfs_open+0x3b/0x370 fs/open.c:1085
       do_open fs/namei.c:3830 [inline]
       path_openat+0x2c81/0x3590 fs/namei.c:3989
       do_filp_open+0x27f/0x4e0 fs/namei.c:4016
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1427
       do_sys_open fs/open.c:1442 [inline]
       __do_sys_openat fs/open.c:1458 [inline]
       __se_sys_openat fs/open.c:1453 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1453
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&cmd->lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730
       nbd_queue_rq+0xcf/0xef0 drivers/block/nbd.c:1196
       blk_mq_dispatch_rq_list+0xad5/0x19d0 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
       __blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309
       blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331
       blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
       blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
       __blk_flush_plug+0x420/0x500 block/blk-core.c:1214
       blk_finish_plug block/blk-core.c:1241 [inline]
       __submit_bio+0x54a/0x6a0 block/blk-core.c:643
       __submit_bio_noacct_mq block/blk-core.c:716 [inline]
       submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:745
       submit_bh fs/buffer.c:2819 [inline]
       block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
       filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2390
       do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960
       read_mapping_folio include/linux/pagemap.h:1023 [inline]
       read_part_sector+0xb3/0x260 block/partitions/core.c:722
       adfspart_check_ICS+0xd9/0x9a0 block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:693
       blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
       bdev_open+0x2d4/0xc50 block/bdev.c:915
       blkdev_open+0x38e/0x4e0 block/fops.c:652
       do_dentry_open+0xdee/0x1960 fs/open.c:955
       vfs_open+0x3b/0x370 fs/open.c:1085
       do_open fs/namei.c:3830 [inline]
       path_openat+0x2c81/0x3590 fs/namei.c:3989
       do_filp_open+0x27f/0x4e0 fs/namei.c:4016
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1427
       do_sys_open fs/open.c:1442 [inline]
       __do_sys_openat fs/open.c:1458 [inline]
       __se_sys_openat fs/open.c:1453 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1453
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (set->srcu){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5899
       srcu_lock_sync include/linux/srcu.h:176 [inline]
       __synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418
       elevator_disable+0x8c/0x3f0 block/elevator.c:657
       blk_mq_elv_switch_none block/blk-mq.c:4950 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
       blk_mq_update_nr_hw_queues+0x599/0x1910 block/blk-mq.c:5065
       nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1475
       nbd_start_device_ioctl drivers/block/nbd.c:1526 [inline]
       __nbd_ioctl drivers/block/nbd.c:1601 [inline]
       nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1641
       blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  set->srcu --> &q->q_usage_counter(io)#53 --> &q->sysfs_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->sysfs_lock);
                               lock(&q->q_usage_counter(io)#53);
                               lock(&q->sysfs_lock);
  sync(set->srcu);

 *** DEADLOCK ***

5 locks held by syz.4.1218/10116:
 #0: ffff888025ac4198 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x13c/0xf40 drivers/block/nbd.c:1634
 #1: ffff888025ac40d8 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xa0/0x1910 block/blk-mq.c:5064
 #2: ffff888143b180a8 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5007 [inline]
 #2: ffff888143b180a8 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: blk_mq_update_nr_hw_queues+0x281/0x1910 block/blk-mq.c:5065
 #3: ffff888143b180e0 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5007 [inline]
 #3: ffff888143b180e0 (&q->q_usage_counter(queue)#37){+.+.}-{0:0}, at: blk_mq_update_nr_hw_queues+0x281/0x1910 block/blk-mq.c:5065
 #4: ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_elv_switch_none block/blk-mq.c:4936 [inline]
 #4: ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
 #4: ffff888143b185d8 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0x34e/0x1910 block/blk-mq.c:5065

stack backtrace:
CPU: 1 UID: 0 PID: 10116 Comm: syz.4.1218 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5899
 srcu_lock_sync include/linux/srcu.h:176 [inline]
 __synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418
 elevator_disable+0x8c/0x3f0 block/elevator.c:657
 blk_mq_elv_switch_none block/blk-mq.c:4950 [inline]
 __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
 blk_mq_update_nr_hw_queues+0x599/0x1910 block/blk-mq.c:5065
 nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1475
 nbd_start_device_ioctl drivers/block/nbd.c:1526 [inline]
 __nbd_ioctl drivers/block/nbd.c:1601 [inline]
 nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1641
 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f521858cda9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5219390038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f52187a5fa0 RCX: 00007f521858cda9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006
RBP: 00007f521860e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f52187a5fa0 R15: 00007ffff7329728
 </TASK>
block nbd4: shutting down sockets