| Message ID | 20181207025523.22703-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blk-mq: re-build queue map in case of kdump kernel | expand |
On 12/6/18 7:55 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 ]--- > > Cc: Christoph Hellwig <hch@lst.de> > Cc: linux-nvme@lists.infradead.org > Cc: David Milburn <dmilburn@redhat.com> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 900550594651..a3e463a726a6 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -38,6 +38,11 @@ > #include "blk-mq-sched.h" > #include "blk-rq-qos.h" > > +static inline bool blk_mq_kdump_kernel(void) > +{ > + return !!is_kdump_kernel(); > +} Let's drop the redundant !! here, and the wrapper? I would imagine the wrapper is handy for testing outside of kdump, but I don't think we should include it in the final. Otherwise this looks fine, I can test it here too.
On Thu, Dec 06, 2018 at 07:57:34PM -0700, Jens Axboe wrote: > On 12/6/18 7:55 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 ]--- > > > > Cc: Christoph Hellwig <hch@lst.de> > > Cc: linux-nvme@lists.infradead.org > > Cc: David Milburn <dmilburn@redhat.com> > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > --- > > block/blk-mq.c | 12 +++++++++--- > > 1 file changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index 900550594651..a3e463a726a6 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -38,6 +38,11 @@ > > #include "blk-mq-sched.h" > > #include "blk-rq-qos.h" > > > > +static inline bool blk_mq_kdump_kernel(void) > > +{ > > + return !!is_kdump_kernel(); > > +} > > Let's drop the redundant !! here, and the wrapper? I would imagine the > wrapper is handy for testing outside of kdump, but I don't think we > should include it in the final. OK. Thanks, Ming
diff --git a/block/blk-mq.c b/block/blk-mq.c index 900550594651..a3e463a726a6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -38,6 +38,11 @@ #include "blk-mq-sched.h" #include "blk-rq-qos.h" +static inline bool blk_mq_kdump_kernel(void) +{ + return !!is_kdump_kernel(); +} + static void blk_mq_poll_stats_start(struct request_queue *q); static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); @@ -2960,7 +2965,7 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) { - if (set->ops->map_queues) { + if (set->ops->map_queues && !blk_mq_kdump_kernel()) { int i; /* @@ -3028,8 +3033,9 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) * memory constrained environment. Limit us to 1 queue and * 64 tags to prevent using too much memory. */ - if (is_kdump_kernel()) { + if (blk_mq_kdump_kernel()) { set->nr_hw_queues = 1; + set->nr_maps = 1; set->queue_depth = min(64U, set->queue_depth); } /* @@ -3051,7 +3057,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) GFP_KERNEL, set->numa_node); if (!set->map[i].mq_map) goto out_free_mq_map; - set->map[i].nr_queues = set->nr_hw_queues; + set->map[i].nr_queues = blk_mq_kdump_kernel() ? 1 : set->nr_hw_queues; } ret = blk_mq_update_queue_map(set);
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 ]--- Cc: Christoph Hellwig <hch@lst.de> Cc: linux-nvme@lists.infradead.org Cc: David Milburn <dmilburn@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/blk-mq.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)