Hi, I get the following WARN_ON when trying to establish a nvmf loopback device backed by zram. My topmost commit is c82be9d2244aacea9851c86f4fb74694c99cd874 + nvmet_cfs=/sys/kernel/config/nvmet/ + nvmet_subsystem=nvmf-test + mkdir -p /sys/kernel/config/nvmet//subsystems/nvmf-test + echo 1 + mkdir /sys/kernel/config/nvmet//subsystems/nvmf-test/namespaces/1 [ 6.163905] nvmet: adding nsid 1 to subsystem nvmf-test + echo -n /dev/zram1 + echo -n 1 + mkdir /sys/kernel/config/nvmet//ports/1 + echo loop + ln -s /sys/kernel/config/nvmet//subsystems/nvmf-test /sys/kernel/config/nvmet//ports/1/subsystems/nvmf-test + echo transport=loop,nqn=nvmf-test [ 6.175710] ------------[ cut here ]------------ [ 6.176181] WARNING: CPU: 1 PID: 207 at block/blk-mq-tag.c:114 blk_mq_get_tag+0x4ec/0x580 [ 6.176922] Modules linked in: nvme_loop nvmet nvme_fabrics nvme_core [ 6.177523] CPU: 1 PID: 207 Comm: sh Not tainted 4.10.0+ #413 [ 6.178048] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 6.179089] Call Trace: [ 6.179331] dump_stack+0x4d/0x68 [ 6.179656] __warn+0x107/0x130 [ 6.179950] warn_slowpath_null+0x18/0x20 [ 6.180326] blk_mq_get_tag+0x4ec/0x580 [ 6.180679] ? __blk_mq_tag_idle+0x40/0x40 [ 6.181069] ? save_stack_trace+0x16/0x20 [ 6.181442] ? wake_atomic_t_function+0x90/0x90 [ 6.181512] ? __vfs_write+0xd1/0x330 [ 6.181512] ? vfs_write+0x10e/0x270 [ 6.181512] ? SyS_write+0xa5/0x130 [ 6.181512] ? entry_SYSCALL_64_fastpath+0x13/0x94 [ 6.181512] ? blk_queue_enter+0x1ac/0x280 [ 6.181512] __blk_mq_alloc_request+0x1c/0x1b0 [ 6.181512] blk_mq_sched_get_request+0x333/0x420 [ 6.181512] ? __list_add_valid+0x2e/0xd0 [ 6.181512] blk_mq_alloc_request+0xb9/0x120 [ 6.181512] ? __blk_mq_alloc_request+0x1b0/0x1b0 [ 6.181512] ? kmemleak_disable+0x70/0x70 [ 6.181512] nvme_alloc_request+0x98/0xb0 [nvme_core] [ 6.181512] __nvme_submit_sync_cmd+0x2c/0x110 [nvme_core] [ 6.181512] nvmf_connect_admin_queue+0x216/0x2b0 [nvme_fabrics] [ 6.181512] ? nvmf_log_connect_error.isra.0+0x130/0x130 [nvme_fabrics] [ 6.181512] ? blk_mq_sched_init+0x2e/0x40 [ 6.181512] ? blk_mq_init_allocated_queue+0x791/0x7c0 [ 6.181512] nvme_loop_configure_admin_queue+0x168/0x270 [nvme_loop] [ 6.181512] nvme_loop_create_ctrl+0x23e/0x8f8 [nvme_loop] [ 6.181512] ? __delete_object+0x59/0xa0 [ 6.181512] ? delete_object_full+0x18/0x20 [ 6.181512] nvmf_dev_write+0xbb1/0xd77 [nvme_fabrics] [ 6.181512] ? nvmf_check_required_opts.isra.2+0xa0/0xa0 [nvme_fabrics] [ 6.181512] ? kasan_slab_free+0x12f/0x180 [ 6.181512] ? save_stack_trace+0x16/0x20 [ 6.181512] ? kasan_slab_free+0xae/0x180 [ 6.181512] ? kmem_cache_free+0x84/0x150 [ 6.181512] ? putname+0x7b/0x80 [ 6.181512] ? do_sys_open+0x23f/0x290 [ 6.181512] ? SyS_open+0x19/0x20 [ 6.181512] ? entry_SYSCALL_64_fastpath+0x13/0x94 [ 6.181512] ? __save_stack_trace+0x7e/0xd0 [ 6.181512] __vfs_write+0xd1/0x330 [ 6.181512] ? restore_nameidata+0x7a/0xa0 [ 6.181512] ? __vfs_read+0x320/0x320 [ 6.181512] ? ptep_set_access_flags+0x2b/0x50 [ 6.181512] ? __handle_mm_fault+0xc9d/0x14e0 [ 6.181512] ? vm_insert_page+0x320/0x320 [ 6.181512] ? locks_remove_posix+0x38/0x70 [ 6.181512] vfs_write+0x10e/0x270 [ 6.181512] SyS_write+0xa5/0x130 [ 6.181512] ? SyS_read+0x130/0x130 [ 6.181512] entry_SYSCALL_64_fastpath+0x13/0x94 [ 6.181512] RIP: 0033:0x7fd6d0de8560 [ 6.181512] RSP: 002b:00007ffd284d2278 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 6.181512] RAX: ffffffffffffffda RBX: 000000000000001c RCX: 00007fd6d0de8560 [ 6.181512] RDX: 000000000000001d RSI: 00007fd6d194a000 RDI: 0000000000000001 [ 6.181512] RBP: 00007fd6d10a9280 R08: 000000000000000a R09: 00007fd6d194c700 [ 6.181512] R10: 0000000001094b50 R11: 0000000000000246 R12: 0000000001094b50 [ 6.181512] R13: 000000000000001c R14: 0000000000000000 R15: 00007ffd284d2228 [ 6.203886] ---[ end trace 96b98033c328af9c ]--- [ 6.204314] nvme nvme0: Connect command failed, error wo/DNR bit: -16395 sh: echo: write error: Resource temporarily unavailable + _fatal + echo 1 + e[ 6.226208] sysrq: SysRq : Power Off cho o + sleep 2 [ 7.880759] ACPI: Preparing to enter system sleep state S5 [ 7.881327] reboot: Power down Is this known or shall I re-test with Jens' latest tree? Nice weekend, Joahnnes -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
