| Message ID | 20230414084008.2085155-1-yukuai1@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for-6.4/block] block/rq_qos: protect rq_qos apis with a new lock | expand |
Hi, 在 2023/04/14 16:40, Yu Kuai 写道: > From: Yu Kuai <yukuai3@huawei.com> > > commit 50e34d78815e ("block: disable the elevator int del_gendisk") > move rq_qos_exit() from disk_release() to del_gendisk(), this will > introduce some problems: > > 1) If rq_qos_add() is triggered by enabling iocost/iolatency through > cgroupfs, then it can concurrent with del_gendisk(), it's not safe to > write 'q->rq_qos' concurrently. > > 2) Activate cgroup policy that is relied on rq_qos will call > rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is > called in the middle, null-ptr-dereference will be triggered in > blkcg_activate_policy(). > > 3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the > disk, then if rq_qos_exit() from del_gendisk() is done before > rq_qos_add(), then memory will be leaked. > > This patch add a new disk level mutex 'rq_qos_mutex': > > 1) The lock will protect rq_qos_exit() directly. > > 2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be > called from disk initialization for now because wbt can't be > destructed until rq_qos_exit(), so it's safe not to protect wbt for > now. Hoever, in case that rq_qos dynamically destruction is supported > in the furture, this patch also protect rq_qos_add() from wbt_init() > directly, this is enough because blk-sysfs already synchronize > writers with disk removal. > > 3) For iocost and iolatency, in order to synchronize disk removal and > cgroup configuration, the lock is held after blkdev_get_no_open() > from blkg_conf_open_bdev(), and is released in blkg_conf_exit(). > In order to fix the above memory leak, disk_live() is checked after > holding the new lock. > Friendly ping ... Thanks, Kuai > Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk") > Signed-off-by: Yu Kuai <yukuai3@huawei.com> > --- > block/blk-cgroup.c | 9 +++++++++ > block/blk-core.c | 1 + > block/blk-rq-qos.c | 20 ++++++-------------- > block/blk-wbt.c | 2 ++ > include/linux/blkdev.h | 1 + > 5 files changed, 19 insertions(+), 14 deletions(-) > > diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c > index 1c1ebeb51003..0d79d864ecb1 100644 > --- a/block/blk-cgroup.c > +++ b/block/blk-cgroup.c > @@ -705,6 +705,13 @@ int blkg_conf_open_bdev(struct blkg_conf_ctx *ctx) > return -ENODEV; > } > > + mutex_lock(&bdev->bd_queue->rq_qos_mutex); > + if (!disk_live(bdev->bd_disk)) { > + blkdev_put_no_open(bdev); > + mutex_unlock(&bdev->bd_queue->rq_qos_mutex); > + return -ENODEV; > + } > + > ctx->body = input; > ctx->bdev = bdev; > return 0; > @@ -849,6 +856,7 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep); > */ > void blkg_conf_exit(struct blkg_conf_ctx *ctx) > __releases(&ctx->bdev->bd_queue->queue_lock) > + __releases(&ctx->bdev->bd_queue->rq_qos_mutex) > { > if (ctx->blkg) { > spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock); > @@ -856,6 +864,7 @@ void blkg_conf_exit(struct blkg_conf_ctx *ctx) > } > > if (ctx->bdev) { > + mutex_unlock(&ctx->bdev->bd_queue->rq_qos_mutex); > blkdev_put_no_open(ctx->bdev); > ctx->body = NULL; > ctx->bdev = NULL; > diff --git a/block/blk-core.c b/block/blk-core.c > index 269765d16cfd..fc7f902bdf5b 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -420,6 +420,7 @@ struct request_queue *blk_alloc_queue(int node_id) > mutex_init(&q->debugfs_mutex); > mutex_init(&q->sysfs_lock); > mutex_init(&q->sysfs_dir_lock); > + mutex_init(&q->rq_qos_mutex); > spin_lock_init(&q->queue_lock); > > init_waitqueue_head(&q->mq_freeze_wq); > diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c > index d8cc820a365e..167be74df4ee 100644 > --- a/block/blk-rq-qos.c > +++ b/block/blk-rq-qos.c > @@ -288,11 +288,13 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data, > > void rq_qos_exit(struct request_queue *q) > { > + mutex_lock(&q->rq_qos_mutex); > while (q->rq_qos) { > struct rq_qos *rqos = q->rq_qos; > q->rq_qos = rqos->next; > rqos->ops->exit(rqos); > } > + mutex_unlock(&q->rq_qos_mutex); > } > > int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, > @@ -300,6 +302,8 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, > { > struct request_queue *q = disk->queue; > > + lockdep_assert_held(&q->rq_qos_mutex); > + > rqos->disk = disk; > rqos->id = id; > rqos->ops = ops; > @@ -307,18 +311,13 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, > /* > * No IO can be in-flight when adding rqos, so freeze queue, which > * is fine since we only support rq_qos for blk-mq queue. > - * > - * Reuse ->queue_lock for protecting against other concurrent > - * rq_qos adding/deleting > */ > blk_mq_freeze_queue(q); > > - spin_lock_irq(&q->queue_lock); > if (rq_qos_id(q, rqos->id)) > goto ebusy; > rqos->next = q->rq_qos; > q->rq_qos = rqos; > - spin_unlock_irq(&q->queue_lock); > > blk_mq_unfreeze_queue(q); > > @@ -330,7 +329,6 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, > > return 0; > ebusy: > - spin_unlock_irq(&q->queue_lock); > blk_mq_unfreeze_queue(q); > return -EBUSY; > } > @@ -340,21 +338,15 @@ void rq_qos_del(struct rq_qos *rqos) > struct request_queue *q = rqos->disk->queue; > struct rq_qos **cur; > > - /* > - * See comment in rq_qos_add() about freezing queue & using > - * ->queue_lock. > - */ > - blk_mq_freeze_queue(q); > + lockdep_assert_held(&q->rq_qos_mutex); > > - spin_lock_irq(&q->queue_lock); > + blk_mq_freeze_queue(q); > for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { > if (*cur == rqos) { > *cur = rqos->next; > break; > } > } > - spin_unlock_irq(&q->queue_lock); > - > blk_mq_unfreeze_queue(q); > > mutex_lock(&q->debugfs_mutex); > diff --git a/block/blk-wbt.c b/block/blk-wbt.c > index e49a48684532..53bf5aa6f9ad 100644 > --- a/block/blk-wbt.c > +++ b/block/blk-wbt.c > @@ -942,7 +942,9 @@ int wbt_init(struct gendisk *disk) > /* > * Assign rwb and add the stats callback. > */ > + mutex_lock(&q->rq_qos_mutex); > ret = rq_qos_add(&rwb->rqos, disk, RQ_QOS_WBT, &wbt_rqos_ops); > + mutex_unlock(&q->rq_qos_mutex); > if (ret) > goto err_free; > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 6ede578dfbc6..17774f55743e 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -395,6 +395,7 @@ struct request_queue { > > struct blk_queue_stats *stats; > struct rq_qos *rq_qos; > + struct mutex rq_qos_mutex; > > const struct blk_mq_ops *mq_ops; > >
在 2023/04/23 16:15, Yu Kuai 写道: > Hi, > > 在 2023/04/14 16:40, Yu Kuai 写道: >> From: Yu Kuai <yukuai3@huawei.com> >> >> commit 50e34d78815e ("block: disable the elevator int del_gendisk") >> move rq_qos_exit() from disk_release() to del_gendisk(), this will >> introduce some problems: >> >> 1) If rq_qos_add() is triggered by enabling iocost/iolatency through >> cgroupfs, then it can concurrent with del_gendisk(), it's not safe to >> write 'q->rq_qos' concurrently. >> >> 2) Activate cgroup policy that is relied on rq_qos will call >> rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is >> called in the middle, null-ptr-dereference will be triggered in >> blkcg_activate_policy(). >> >> 3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the >> disk, then if rq_qos_exit() from del_gendisk() is done before >> rq_qos_add(), then memory will be leaked. >> >> This patch add a new disk level mutex 'rq_qos_mutex': >> >> 1) The lock will protect rq_qos_exit() directly. >> >> 2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be >> called from disk initialization for now because wbt can't be >> destructed until rq_qos_exit(), so it's safe not to protect wbt for >> now. Hoever, in case that rq_qos dynamically destruction is supported >> in the furture, this patch also protect rq_qos_add() from wbt_init() >> directly, this is enough because blk-sysfs already synchronize >> writers with disk removal. >> >> 3) For iocost and iolatency, in order to synchronize disk removal and >> cgroup configuration, the lock is held after blkdev_get_no_open() >> from blkg_conf_open_bdev(), and is released in blkg_conf_exit(). >> In order to fix the above memory leak, disk_live() is checked after >> holding the new lock. >> > > Friendly ping ... Friendly ping ... > > Thanks, > Kuai >> Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk") >> Signed-off-by: Yu Kuai <yukuai3@huawei.com> >> --- >> block/blk-cgroup.c | 9 +++++++++ >> block/blk-core.c | 1 + >> block/blk-rq-qos.c | 20 ++++++-------------- >> block/blk-wbt.c | 2 ++ >> include/linux/blkdev.h | 1 + >> 5 files changed, 19 insertions(+), 14 deletions(-) >> >> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c >> index 1c1ebeb51003..0d79d864ecb1 100644 >> --- a/block/blk-cgroup.c >> +++ b/block/blk-cgroup.c >> @@ -705,6 +705,13 @@ int blkg_conf_open_bdev(struct blkg_conf_ctx *ctx) >> return -ENODEV; >> } >> + mutex_lock(&bdev->bd_queue->rq_qos_mutex); >> + if (!disk_live(bdev->bd_disk)) { >> + blkdev_put_no_open(bdev); >> + mutex_unlock(&bdev->bd_queue->rq_qos_mutex); >> + return -ENODEV; >> + } >> + >> ctx->body = input; >> ctx->bdev = bdev; >> return 0; >> @@ -849,6 +856,7 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep); >> */ >> void blkg_conf_exit(struct blkg_conf_ctx *ctx) >> __releases(&ctx->bdev->bd_queue->queue_lock) >> + __releases(&ctx->bdev->bd_queue->rq_qos_mutex) >> { >> if (ctx->blkg) { >> spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock); >> @@ -856,6 +864,7 @@ void blkg_conf_exit(struct blkg_conf_ctx *ctx) >> } >> if (ctx->bdev) { >> + mutex_unlock(&ctx->bdev->bd_queue->rq_qos_mutex); >> blkdev_put_no_open(ctx->bdev); >> ctx->body = NULL; >> ctx->bdev = NULL; >> diff --git a/block/blk-core.c b/block/blk-core.c >> index 269765d16cfd..fc7f902bdf5b 100644 >> --- a/block/blk-core.c >> +++ b/block/blk-core.c >> @@ -420,6 +420,7 @@ struct request_queue *blk_alloc_queue(int node_id) >> mutex_init(&q->debugfs_mutex); >> mutex_init(&q->sysfs_lock); >> mutex_init(&q->sysfs_dir_lock); >> + mutex_init(&q->rq_qos_mutex); >> spin_lock_init(&q->queue_lock); >> init_waitqueue_head(&q->mq_freeze_wq); >> diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c >> index d8cc820a365e..167be74df4ee 100644 >> --- a/block/blk-rq-qos.c >> +++ b/block/blk-rq-qos.c >> @@ -288,11 +288,13 @@ void rq_qos_wait(struct rq_wait *rqw, void >> *private_data, >> void rq_qos_exit(struct request_queue *q) >> { >> + mutex_lock(&q->rq_qos_mutex); >> while (q->rq_qos) { >> struct rq_qos *rqos = q->rq_qos; >> q->rq_qos = rqos->next; >> rqos->ops->exit(rqos); >> } >> + mutex_unlock(&q->rq_qos_mutex); >> } >> int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum >> rq_qos_id id, >> @@ -300,6 +302,8 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk >> *disk, enum rq_qos_id id, >> { >> struct request_queue *q = disk->queue; >> + lockdep_assert_held(&q->rq_qos_mutex); >> + >> rqos->disk = disk; >> rqos->id = id; >> rqos->ops = ops; >> @@ -307,18 +311,13 @@ int rq_qos_add(struct rq_qos *rqos, struct >> gendisk *disk, enum rq_qos_id id, >> /* >> * No IO can be in-flight when adding rqos, so freeze queue, which >> * is fine since we only support rq_qos for blk-mq queue. >> - * >> - * Reuse ->queue_lock for protecting against other concurrent >> - * rq_qos adding/deleting >> */ >> blk_mq_freeze_queue(q); >> - spin_lock_irq(&q->queue_lock); >> if (rq_qos_id(q, rqos->id)) >> goto ebusy; >> rqos->next = q->rq_qos; >> q->rq_qos = rqos; >> - spin_unlock_irq(&q->queue_lock); >> blk_mq_unfreeze_queue(q); >> @@ -330,7 +329,6 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk >> *disk, enum rq_qos_id id, >> return 0; >> ebusy: >> - spin_unlock_irq(&q->queue_lock); >> blk_mq_unfreeze_queue(q); >> return -EBUSY; >> } >> @@ -340,21 +338,15 @@ void rq_qos_del(struct rq_qos *rqos) >> struct request_queue *q = rqos->disk->queue; >> struct rq_qos **cur; >> - /* >> - * See comment in rq_qos_add() about freezing queue & using >> - * ->queue_lock. >> - */ >> - blk_mq_freeze_queue(q); >> + lockdep_assert_held(&q->rq_qos_mutex); >> - spin_lock_irq(&q->queue_lock); >> + blk_mq_freeze_queue(q); >> for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { >> if (*cur == rqos) { >> *cur = rqos->next; >> break; >> } >> } >> - spin_unlock_irq(&q->queue_lock); >> - >> blk_mq_unfreeze_queue(q); >> mutex_lock(&q->debugfs_mutex); >> diff --git a/block/blk-wbt.c b/block/blk-wbt.c >> index e49a48684532..53bf5aa6f9ad 100644 >> --- a/block/blk-wbt.c >> +++ b/block/blk-wbt.c >> @@ -942,7 +942,9 @@ int wbt_init(struct gendisk *disk) >> /* >> * Assign rwb and add the stats callback. >> */ >> + mutex_lock(&q->rq_qos_mutex); >> ret = rq_qos_add(&rwb->rqos, disk, RQ_QOS_WBT, &wbt_rqos_ops); >> + mutex_unlock(&q->rq_qos_mutex); >> if (ret) >> goto err_free; >> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h >> index 6ede578dfbc6..17774f55743e 100644 >> --- a/include/linux/blkdev.h >> +++ b/include/linux/blkdev.h >> @@ -395,6 +395,7 @@ struct request_queue { >> struct blk_queue_stats *stats; >> struct rq_qos *rq_qos; >> + struct mutex rq_qos_mutex; >> const struct blk_mq_ops *mq_ops; >> > > . >
On Fri, Apr 14, 2023 at 04:40:08PM +0800, Yu Kuai wrote: > From: Yu Kuai <yukuai3@huawei.com> > > commit 50e34d78815e ("block: disable the elevator int del_gendisk") > move rq_qos_exit() from disk_release() to del_gendisk(), this will > introduce some problems: > > 1) If rq_qos_add() is triggered by enabling iocost/iolatency through > cgroupfs, then it can concurrent with del_gendisk(), it's not safe to > write 'q->rq_qos' concurrently. > > 2) Activate cgroup policy that is relied on rq_qos will call > rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is > called in the middle, null-ptr-dereference will be triggered in > blkcg_activate_policy(). > > 3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the > disk, then if rq_qos_exit() from del_gendisk() is done before > rq_qos_add(), then memory will be leaked. > > This patch add a new disk level mutex 'rq_qos_mutex': > > 1) The lock will protect rq_qos_exit() directly. > > 2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be > called from disk initialization for now because wbt can't be > destructed until rq_qos_exit(), so it's safe not to protect wbt for > now. Hoever, in case that rq_qos dynamically destruction is supported > in the furture, this patch also protect rq_qos_add() from wbt_init() > directly, this is enough because blk-sysfs already synchronize > writers with disk removal. > > 3) For iocost and iolatency, in order to synchronize disk removal and > cgroup configuration, the lock is held after blkdev_get_no_open() > from blkg_conf_open_bdev(), and is released in blkg_conf_exit(). > In order to fix the above memory leak, disk_live() is checked after > holding the new lock. > > Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk") > Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Thanks.
On Fri, 14 Apr 2023 16:40:08 +0800, Yu Kuai wrote: > commit 50e34d78815e ("block: disable the elevator int del_gendisk") > move rq_qos_exit() from disk_release() to del_gendisk(), this will > introduce some problems: > > 1) If rq_qos_add() is triggered by enabling iocost/iolatency through > cgroupfs, then it can concurrent with del_gendisk(), it's not safe to > write 'q->rq_qos' concurrently. > > [...] Applied, thanks! [1/1] block/rq_qos: protect rq_qos apis with a new lock commit: a13bd91be22318768d55470cbc0b0f4488ef9edf Best regards,
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1c1ebeb51003..0d79d864ecb1 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -705,6 +705,13 @@ int blkg_conf_open_bdev(struct blkg_conf_ctx *ctx) return -ENODEV; } + mutex_lock(&bdev->bd_queue->rq_qos_mutex); + if (!disk_live(bdev->bd_disk)) { + blkdev_put_no_open(bdev); + mutex_unlock(&bdev->bd_queue->rq_qos_mutex); + return -ENODEV; + } + ctx->body = input; ctx->bdev = bdev; return 0; @@ -849,6 +856,7 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep); */ void blkg_conf_exit(struct blkg_conf_ctx *ctx) __releases(&ctx->bdev->bd_queue->queue_lock) + __releases(&ctx->bdev->bd_queue->rq_qos_mutex) { if (ctx->blkg) { spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock); @@ -856,6 +864,7 @@ void blkg_conf_exit(struct blkg_conf_ctx *ctx) } if (ctx->bdev) { + mutex_unlock(&ctx->bdev->bd_queue->rq_qos_mutex); blkdev_put_no_open(ctx->bdev); ctx->body = NULL; ctx->bdev = NULL; diff --git a/block/blk-core.c b/block/blk-core.c index 269765d16cfd..fc7f902bdf5b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -420,6 +420,7 @@ struct request_queue *blk_alloc_queue(int node_id) mutex_init(&q->debugfs_mutex); mutex_init(&q->sysfs_lock); mutex_init(&q->sysfs_dir_lock); + mutex_init(&q->rq_qos_mutex); spin_lock_init(&q->queue_lock); init_waitqueue_head(&q->mq_freeze_wq); diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c index d8cc820a365e..167be74df4ee 100644 --- a/block/blk-rq-qos.c +++ b/block/blk-rq-qos.c @@ -288,11 +288,13 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data, void rq_qos_exit(struct request_queue *q) { + mutex_lock(&q->rq_qos_mutex); while (q->rq_qos) { struct rq_qos *rqos = q->rq_qos; q->rq_qos = rqos->next; rqos->ops->exit(rqos); } + mutex_unlock(&q->rq_qos_mutex); } int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, @@ -300,6 +302,8 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, { struct request_queue *q = disk->queue; + lockdep_assert_held(&q->rq_qos_mutex); + rqos->disk = disk; rqos->id = id; rqos->ops = ops; @@ -307,18 +311,13 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, /* * No IO can be in-flight when adding rqos, so freeze queue, which * is fine since we only support rq_qos for blk-mq queue. - * - * Reuse ->queue_lock for protecting against other concurrent - * rq_qos adding/deleting */ blk_mq_freeze_queue(q); - spin_lock_irq(&q->queue_lock); if (rq_qos_id(q, rqos->id)) goto ebusy; rqos->next = q->rq_qos; q->rq_qos = rqos; - spin_unlock_irq(&q->queue_lock); blk_mq_unfreeze_queue(q); @@ -330,7 +329,6 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, return 0; ebusy: - spin_unlock_irq(&q->queue_lock); blk_mq_unfreeze_queue(q); return -EBUSY; } @@ -340,21 +338,15 @@ void rq_qos_del(struct rq_qos *rqos) struct request_queue *q = rqos->disk->queue; struct rq_qos **cur; - /* - * See comment in rq_qos_add() about freezing queue & using - * ->queue_lock. - */ - blk_mq_freeze_queue(q); + lockdep_assert_held(&q->rq_qos_mutex); - spin_lock_irq(&q->queue_lock); + blk_mq_freeze_queue(q); for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { if (*cur == rqos) { *cur = rqos->next; break; } } - spin_unlock_irq(&q->queue_lock); - blk_mq_unfreeze_queue(q); mutex_lock(&q->debugfs_mutex); diff --git a/block/blk-wbt.c b/block/blk-wbt.c index e49a48684532..53bf5aa6f9ad 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -942,7 +942,9 @@ int wbt_init(struct gendisk *disk) /* * Assign rwb and add the stats callback. */ + mutex_lock(&q->rq_qos_mutex); ret = rq_qos_add(&rwb->rqos, disk, RQ_QOS_WBT, &wbt_rqos_ops); + mutex_unlock(&q->rq_qos_mutex); if (ret) goto err_free; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6ede578dfbc6..17774f55743e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -395,6 +395,7 @@ struct request_queue { struct blk_queue_stats *stats; struct rq_qos *rq_qos; + struct mutex rq_qos_mutex; const struct blk_mq_ops *mq_ops;