From 737f98cfe7de8df7433a4d846850aa8efa44bd48 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 22 Feb 2017 18:13:59 +0800 Subject: blk-mq: initialize mq kobjects in blk_mq_init_allocated_queue() Both q->mq_kobj and sw queues' kobjects should have been initialized once, instead of doing that each add_disk context. Also this patch removes clearing of ctx in blk_mq_init_cpu_queues() because percpu allocator fills zero to allocated variable. This patch fixes one issue[1] reported from Omar. [1] kernel wearning when doing unbind/bind on one scsi-mq device [ 19.347924] kobject (ffff8800791ea0b8): tried to init an initialized object, something is seriously wrong. [ 19.349781] CPU: 1 PID: 84 Comm: kworker/u8:1 Not tainted 4.10.0-rc7-00210-g53f39eeaa263 #34 [ 19.350686] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-20161122_114906-anatol 04/01/2014 [ 19.350920] Workqueue: events_unbound async_run_entry_fn [ 19.350920] Call Trace: [ 19.350920] dump_stack+0x63/0x83 [ 19.350920] kobject_init+0x77/0x90 [ 19.350920] blk_mq_register_dev+0x40/0x130 [ 19.350920] blk_register_queue+0xb6/0x190 [ 19.350920] device_add_disk+0x1ec/0x4b0 [ 19.350920] sd_probe_async+0x10d/0x1c0 [sd_mod] [ 19.350920] async_run_entry_fn+0x48/0x150 [ 19.350920] process_one_work+0x1d0/0x480 [ 19.350920] worker_thread+0x48/0x4e0 [ 19.350920] kthread+0x101/0x140 [ 19.350920] ? process_one_work+0x480/0x480 [ 19.350920] ? kthread_create_on_node+0x60/0x60 [ 19.350920] ret_from_fork+0x2c/0x40 Cc: Omar Sandoval Signed-off-by: Ming Lei Tested-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe --- block/blk-mq.h | 1 + 1 file changed, 1 insertion(+) (limited to 'block/blk-mq.h') diff --git a/block/blk-mq.h b/block/blk-mq.h index 088ced003c13..ad8bfd7473ef 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -77,6 +77,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, /* * sysfs helpers */ +extern void blk_mq_sysfs_init(struct request_queue *q); extern int blk_mq_sysfs_register(struct request_queue *q); extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); -- cgit From 7ea5fe31c12dd8bcf4a9c5a4a7e8e23826a9a3b8 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 22 Feb 2017 18:14:00 +0800 Subject: blk-mq: make lifetime consitent between q/ctx and its kobject Currently from kobject view, both q->mq_kobj and ctx->kobj can be released during one cycle of blk_mq_register_dev() and blk_mq_unregister_dev(). Actually, sw queue's lifetime is same with its request queue's, which is covered by request_queue->kobj. So we don't need to call kobject_put() for the two kinds of kobject in __blk_mq_unregister_dev(), instead we do that in release handler of request queue. Signed-off-by: Ming Lei Tested-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe --- block/blk-mq-sysfs.c | 20 +++++++++++++------- block/blk-mq.c | 7 ++++++- block/blk-mq.h | 1 + 3 files changed, 20 insertions(+), 8 deletions(-) (limited to 'block/blk-mq.h') diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 124305407c80..77fb238af2be 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -242,15 +242,11 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) { struct blk_mq_hw_ctx *hctx; - struct blk_mq_ctx *ctx; - int i, j; + int i; queue_for_each_hw_ctx(q, hctx, i) { blk_mq_unregister_hctx(hctx); - hctx_for_each_ctx(hctx, ctx, j) - kobject_put(&ctx->kobj); - kobject_put(&hctx->kobj); } @@ -258,8 +254,6 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) kobject_uevent(&q->mq_kobj, KOBJ_REMOVE); kobject_del(&q->mq_kobj); - kobject_put(&q->mq_kobj); - kobject_put(&dev->kobj); q->mq_sysfs_init_done = false; @@ -277,6 +271,18 @@ void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx) kobject_init(&hctx->kobj, &blk_mq_hw_ktype); } +void blk_mq_sysfs_deinit(struct request_queue *q) +{ + struct blk_mq_ctx *ctx; + int cpu; + + for_each_possible_cpu(cpu) { + ctx = per_cpu_ptr(q->queue_ctx, cpu); + kobject_put(&ctx->kobj); + } + kobject_put(&q->mq_kobj); +} + void blk_mq_sysfs_init(struct request_queue *q) { struct blk_mq_ctx *ctx; diff --git a/block/blk-mq.c b/block/blk-mq.c index ed4b55176cdd..b985c236f50f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2264,7 +2264,12 @@ void blk_mq_release(struct request_queue *q) kfree(q->queue_hw_ctx); - /* ctx kobj stays in queue_ctx */ + /* + * release .mq_kobj and sw queue's kobject now because + * both share lifetime with request queue. + */ + blk_mq_sysfs_deinit(q); + free_percpu(q->queue_ctx); } diff --git a/block/blk-mq.h b/block/blk-mq.h index ad8bfd7473ef..b79f9a7d8cf6 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -78,6 +78,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, * sysfs helpers */ extern void blk_mq_sysfs_init(struct request_queue *q); +extern void blk_mq_sysfs_deinit(struct request_queue *q); extern int blk_mq_sysfs_register(struct request_queue *q); extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); -- cgit