From e4dc2b32df5573b077f6723e01cf761d236d5113 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Tue, 30 May 2017 14:39:11 -0400 Subject: blk-mq: Take tagset lock when updating hw queues The tagset lock needs to be held when iterating the tag_list, so a lockdep assert was added when updating number of hardware queues. The drivers calling this API, however, were unaware of the new requirement, so are failing the assertion. This patch takes the lock within the blk-mq function so the drivers do not have to be modified in order to be safe. Fixes: 705cda97e ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list") Reported-by: Gabriel Krisman Bertazi Reviewed-by: Bart Van Assche Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- block/blk-mq.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index f2224ffd225d..1bcccedcc74f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2641,7 +2641,8 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) return ret; } -void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) +static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, + int nr_hw_queues) { struct request_queue *q; @@ -2665,6 +2666,13 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) list_for_each_entry(q, &set->tag_list, tag_set_list) blk_mq_unfreeze_queue(q); } + +void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) +{ + mutex_lock(&set->tag_list_lock); + __blk_mq_update_nr_hw_queues(set, nr_hw_queues); + mutex_unlock(&set->tag_list_lock); +} EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); /* Enable polling stats and return whether they were already enabled. */ -- cgit v1.2.1 From dad7a3be4960e5545882a0cd8d7613af22874314 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 6 Jun 2017 23:21:59 +0800 Subject: blk-mq: pass correct hctx to blk_mq_try_issue_directly When direct issue is done on request picked up from plug list, the hctx need to be updated with the actual hw queue, otherwise wrong hctx is used and may hurt performance, especially when wrong SRCU readlock is acquired/released Reported-by: Bart Van Assche Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index 1bcccedcc74f..4ddfa019face 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1619,9 +1619,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) blk_mq_put_ctx(data.ctx); - if (same_queue_rq) + if (same_queue_rq) { + data.hctx = blk_mq_map_queue(q, + same_queue_rq->mq_ctx->cpu); blk_mq_try_issue_directly(data.hctx, same_queue_rq, &cookie); + } } else if (q->nr_hw_queues > 1 && is_sync) { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); -- cgit v1.2.1 From d964f04a8fde84d978eff0d96561faa6e8de24de Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 6 Jun 2017 23:22:00 +0800 Subject: blk-mq: fix direct issue If queue is stopped, we shouldn't dispatch request into driver and hardware, unfortunately the check is removed in bd166ef183c2(blk-mq-sched: add framework for MQ capable IO schedulers). This patch fixes the issue by moving the check back into __blk_mq_try_issue_directly(). This patch fixes request use-after-free[1][2] during canceling requets of NVMe in nvme_dev_disable(), which can be triggered easily during NVMe reset & remove test. [1] oops kernel log when CONFIG_BLK_DEV_INTEGRITY is on [ 103.412969] BUG: unable to handle kernel NULL pointer dereference at 000000000000000a [ 103.412980] IP: bio_integrity_advance+0x48/0xf0 [ 103.412981] PGD 275a88067 [ 103.412981] P4D 275a88067 [ 103.412982] PUD 276c43067 [ 103.412983] PMD 0 [ 103.412984] [ 103.412986] Oops: 0000 [#1] SMP [ 103.412989] Modules linked in: vfat fat intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel crypto_simd cryptd ipmi_ssif iTCO_wdt iTCO_vendor_support mxm_wmi glue_helper dcdbas ipmi_si mei_me pcspkr mei sg ipmi_devintf lpc_ich ipmi_msghandler shpchp acpi_power_meter wmi nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel nvme ahci nvme_core libahci libata tg3 i2c_core megaraid_sas ptp pps_core dm_mirror dm_region_hash dm_log dm_mod [ 103.413035] CPU: 0 PID: 102 Comm: kworker/0:2 Not tainted 4.11.0+ #1 [ 103.413036] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.2.5 09/06/2016 [ 103.413041] Workqueue: events nvme_remove_dead_ctrl_work [nvme] [ 103.413043] task: ffff9cc8775c8000 task.stack: ffffc033c252c000 [ 103.413045] RIP: 0010:bio_integrity_advance+0x48/0xf0 [ 103.413046] RSP: 0018:ffffc033c252fc10 EFLAGS: 00010202 [ 103.413048] RAX: 0000000000000000 RBX: ffff9cc8720a8cc0 RCX: ffff9cca72958240 [ 103.413049] RDX: ffff9cca72958000 RSI: 0000000000000008 RDI: ffff9cc872537f00 [ 103.413049] RBP: ffffc033c252fc28 R08: 0000000000000000 R09: ffffffffb963a0d5 [ 103.413050] R10: 000000000000063e R11: 0000000000000000 R12: ffff9cc8720a8d18 [ 103.413051] R13: 0000000000001000 R14: ffff9cc872682e00 R15: 00000000fffffffb [ 103.413053] FS: 0000000000000000(0000) GS:ffff9cc877c00000(0000) knlGS:0000000000000000 [ 103.413054] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 103.413055] CR2: 000000000000000a CR3: 0000000276c41000 CR4: 00000000001406f0 [ 103.413056] Call Trace: [ 103.413063] bio_advance+0x2a/0xe0 [ 103.413067] blk_update_request+0x76/0x330 [ 103.413072] blk_mq_end_request+0x1a/0x70 [ 103.413074] blk_mq_dispatch_rq_list+0x370/0x410 [ 103.413076] ? blk_mq_flush_busy_ctxs+0x94/0xe0 [ 103.413080] blk_mq_sched_dispatch_requests+0x173/0x1a0 [ 103.413083] __blk_mq_run_hw_queue+0x8e/0xa0 [ 103.413085] __blk_mq_delay_run_hw_queue+0x9d/0xa0 [ 103.413088] blk_mq_start_hw_queue+0x17/0x20 [ 103.413090] blk_mq_start_hw_queues+0x32/0x50 [ 103.413095] nvme_kill_queues+0x54/0x80 [nvme_core] [ 103.413097] nvme_remove_dead_ctrl_work+0x1f/0x40 [nvme] [ 103.413103] process_one_work+0x149/0x360 [ 103.413105] worker_thread+0x4d/0x3c0 [ 103.413109] kthread+0x109/0x140 [ 103.413111] ? rescuer_thread+0x380/0x380 [ 103.413113] ? kthread_park+0x60/0x60 [ 103.413120] ret_from_fork+0x2c/0x40 [ 103.413121] Code: 08 4c 8b 63 50 48 8b 80 80 00 00 00 48 8b 90 d0 03 00 00 31 c0 48 83 ba 40 02 00 00 00 48 8d 8a 40 02 00 00 48 0f 45 c1 c1 ee 09 <0f> b6 48 0a 0f b6 40 09 41 89 f5 83 e9 09 41 d3 ed 44 0f af e8 [ 103.413145] RIP: bio_integrity_advance+0x48/0xf0 RSP: ffffc033c252fc10 [ 103.413146] CR2: 000000000000000a [ 103.413157] ---[ end trace cd6875d16eb5a11e ]--- [ 103.455368] Kernel panic - not syncing: Fatal exception [ 103.459826] Kernel Offset: 0x37600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 103.850916] ---[ end Kernel panic - not syncing: Fatal exception [ 103.857637] sched: Unexpected reschedule of offline CPU#1! [ 103.863762] ------------[ cut here ]------------ [2] kernel hang in blk_mq_freeze_queue_wait() when CONFIG_BLK_DEV_INTEGRITY is off [ 247.129825] INFO: task nvme-test:1772 blocked for more than 120 seconds. [ 247.137311] Not tainted 4.12.0-rc2.upstream+ #4 [ 247.142954] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 247.151704] Call Trace: [ 247.154445] __schedule+0x28a/0x880 [ 247.158341] schedule+0x36/0x80 [ 247.161850] blk_mq_freeze_queue_wait+0x4b/0xb0 [ 247.166913] ? remove_wait_queue+0x60/0x60 [ 247.171485] blk_freeze_queue+0x1a/0x20 [ 247.175770] blk_cleanup_queue+0x7f/0x140 [ 247.180252] nvme_ns_remove+0xa3/0xb0 [nvme_core] [ 247.185503] nvme_remove_namespaces+0x32/0x50 [nvme_core] [ 247.191532] nvme_uninit_ctrl+0x2d/0xa0 [nvme_core] [ 247.196977] nvme_remove+0x70/0x110 [nvme] [ 247.201545] pci_device_remove+0x39/0xc0 [ 247.205927] device_release_driver_internal+0x141/0x200 [ 247.211761] device_release_driver+0x12/0x20 [ 247.216531] pci_stop_bus_device+0x8c/0xa0 [ 247.221104] pci_stop_and_remove_bus_device_locked+0x1a/0x30 [ 247.227420] remove_store+0x7c/0x90 [ 247.231320] dev_attr_store+0x18/0x30 [ 247.235409] sysfs_kf_write+0x3a/0x50 [ 247.239497] kernfs_fop_write+0xff/0x180 [ 247.243867] __vfs_write+0x37/0x160 [ 247.247757] ? selinux_file_permission+0xe5/0x120 [ 247.253011] ? security_file_permission+0x3b/0xc0 [ 247.258260] vfs_write+0xb2/0x1b0 [ 247.261964] ? syscall_trace_enter+0x1d0/0x2b0 [ 247.266924] SyS_write+0x55/0xc0 [ 247.270540] do_syscall_64+0x67/0x150 [ 247.274636] entry_SYSCALL64_slow_path+0x25/0x25 [ 247.279794] RIP: 0033:0x7f5c96740840 [ 247.283785] RSP: 002b:00007ffd00e87ee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 247.292238] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f5c96740840 [ 247.300194] RDX: 0000000000000002 RSI: 00007f5c97060000 RDI: 0000000000000001 [ 247.308159] RBP: 00007f5c97060000 R08: 000000000000000a R09: 00007f5c97059740 [ 247.316123] R10: 0000000000000001 R11: 0000000000000246 R12: 00007f5c96a14400 [ 247.324087] R13: 0000000000000002 R14: 0000000000000001 R15: 0000000000000000 [ 370.016340] INFO: task nvme-test:1772 blocked for more than 120 seconds. Fixes: 12d70958a2e8(blk-mq: don't fail allocating driver tag for stopped hw queue) Cc: stable@vger.kernel.org Signed-off-by: Ming Lei Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index 4ddfa019face..bb66c96850b1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1461,22 +1461,28 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); } -static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie, - bool may_sleep) +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, + struct request *rq, + blk_qc_t *cookie, bool may_sleep) { struct request_queue *q = rq->q; struct blk_mq_queue_data bd = { .rq = rq, .last = true, }; - struct blk_mq_hw_ctx *hctx; blk_qc_t new_cookie; int ret; + bool run_queue = true; + + if (blk_mq_hctx_stopped(hctx)) { + run_queue = false; + goto insert; + } if (q->elevator) goto insert; - if (!blk_mq_get_driver_tag(rq, &hctx, false)) + if (!blk_mq_get_driver_tag(rq, NULL, false)) goto insert; new_cookie = request_to_qc_t(hctx, rq); @@ -1500,7 +1506,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie, __blk_mq_requeue_request(rq); insert: - blk_mq_sched_insert_request(rq, false, true, false, may_sleep); + blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep); } static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, @@ -1508,7 +1514,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, { if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { rcu_read_lock(); - __blk_mq_try_issue_directly(rq, cookie, false); + __blk_mq_try_issue_directly(hctx, rq, cookie, false); rcu_read_unlock(); } else { unsigned int srcu_idx; @@ -1516,7 +1522,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, might_sleep(); srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); - __blk_mq_try_issue_directly(rq, cookie, true); + __blk_mq_try_issue_directly(hctx, rq, cookie, true); srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); } } -- cgit v1.2.1