On 12/6/18 8:03 PM, Ming Lei wrote: > Now almost all .map_queues() implementation based on managed irq > affinity doesn't update queue mapping and it just retrieves the > old built mapping, so if nr_hw_queues is changed, the mapping talbe > includes stale mapping. And only blk_mq_map_queues() may rebuild > the mapping talbe. > > One case is that we limit .nr_hw_queues as 1 in case of kdump kernel. > However, drivers often builds queue mapping before allocating tagset > via pci_alloc_irq_vectors_affinity(), but set->nr_hw_queues can be set > as 1 in case of kdump kernel, so wrong queue mapping is used, and > kernel panic[1] is observed during booting. > > This patch fixes the kernel panic triggerd on nvme by rebulding the > mapping table via blk_mq_map_queues(). > > [1] kernel panic log > [ 4.438371] nvme nvme0: 16/0/0 default/read/poll queues > [ 4.443277] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000098 > [ 4.444681] PGD 0 P4D 0 > [ 4.445367] Oops: 0000 [#1] SMP NOPTI > [ 4.446342] CPU: 3 PID: 201 Comm: kworker/u33:10 Not tainted > 4.20.0-rc5-00664-g5eb02f7ee1eb-dirty #459 > [ 4.447630] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS > 1.10.2-2.fc27 04/01/2014 > [ 4.448689] Workqueue: nvme-wq nvme_scan_work [nvme_core] > [ 4.449368] RIP: 0010:blk_mq_map_swqueue+0xfb/0x222 > [ 4.450596] Code: 04 f5 20 28 ef 81 48 89 c6 39 55 30 76 93 89 d0 48 c1 e0 > 04 48 03 83 f8 05 00 00 48 8b 00 42 8b 3c 28 48 8b 43 58 48 8b 04 f8 <48> 8b > b8 98 00 00 00 4c 0f a3 37 72 42 f0 4c 0f ab 37 66 8b b8 f6 > [ 4.453132] RSP: 0018:ffffc900023b3cd8 EFLAGS: 00010286 > [ 4.454061] RAX: 0000000000000000 RBX: ffff888174448000 RCX: > 0000000000000001 > [ 4.456480] RDX: 0000000000000001 RSI: ffffe8feffc506c0 RDI: > 0000000000000001 > [ 4.458750] RBP: ffff88810722d008 R08: ffff88817647a880 R09: > 0000000000000002 > [ 4.464580] R10: ffffc900023b3c10 R11: 0000000000000004 R12: > ffff888174448538 > [ 4.467803] R13: 0000000000000004 R14: 0000000000000001 R15: > 0000000000000001 > [ 4.469220] FS: 0000000000000000(0000) GS:ffff88817bac0000(0000) > knlGS:0000000000000000 > [ 4.471554] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 4.472464] CR2: 0000000000000098 CR3: 0000000174e4e001 CR4: > 0000000000760ee0 > [ 4.474264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 4.476007] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > 0000000000000400 > [ 4.477061] PKRU: 55555554 > [ 4.477464] Call Trace: > [ 4.478731] blk_mq_init_allocated_queue+0x36a/0x3ad > [ 4.479595] blk_mq_init_queue+0x32/0x4e > [ 4.480178] nvme_validate_ns+0x98/0x623 [nvme_core] > [ 4.480963] ? nvme_submit_sync_cmd+0x1b/0x20 [nvme_core] > [ 4.481685] ? nvme_identify_ctrl.isra.8+0x70/0xa0 [nvme_core] > [ 4.482601] nvme_scan_work+0x23a/0x29b [nvme_core] > [ 4.483269] ? _raw_spin_unlock_irqrestore+0x25/0x38 > [ 4.483930] ? try_to_wake_up+0x38d/0x3b3 > [ 4.484478] ? process_one_work+0x179/0x2fc > [ 4.485118] process_one_work+0x1d3/0x2fc > [ 4.485655] ? rescuer_thread+0x2ae/0x2ae > [ 4.486196] worker_thread+0x1e9/0x2be > [ 4.486841] kthread+0x115/0x11d > [ 4.487294] ? kthread_park+0x76/0x76 > [ 4.487784] ret_from_fork+0x3a/0x50 > [ 4.488322] Modules linked in: nvme nvme_core qemu_fw_cfg virtio_scsi > ip_tables > [ 4.489428] Dumping ftrace buffer: > [ 4.489939] (ftrace buffer empty) > [ 4.490492] CR2: 0000000000000098 > [ 4.491052] ---[ end trace 03cd268ad5a86ff7 ]---
Works for me, tested various configs and stubbed out the kdump check. Thanks for fixing this, applied to 4.21. -- Jens Axboe
