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authorLinus Torvalds <torvalds@linux-foundation.org>2014-11-14 14:03:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-11-14 14:03:23 -0800
commit6f0d7a9eb60d70f22d71f00b2c762e255881ab31 (patch)
tree433b43268507505d3fa1c0dea3f929031ae52661
parent78646f62dbaba99ab0ae50afbe8c2d1876cb4d33 (diff)
parent7f60dcaaf91e911002007c7ae885ff6ef0f36c0d (diff)
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe: "Four small fixes that should be merged for the current 3.18-rc series. This pull request contains: - a minor bugfix for computation of best IO priority given two merging requests. From Jan Kara. - the final (final) merge count issue that has been plaguing virtio-blk. From Ming Lei. - enable parallel reinit notify for blk-mq queues, to combine the cost of an RCU grace period across lots of devices. From Tejun Heo. - an error handling fix for the SCSI_IOCTL_SEND_COMMAND ioctl. From Tony Battersby" * 'for-linus' of git://git.kernel.dk/linux-block: block: blk-merge: fix blk_recount_segments() scsi: Fix more error handling in SCSI_IOCTL_SEND_COMMAND blk-mq: make mq_queue_reinit_notify() freeze queues in parallel block: Fix computation of merged request priority
-rw-r--r--block/blk-merge.c19
-rw-r--r--block/blk-mq.c41
-rw-r--r--block/ioprio.c14
-rw-r--r--block/scsi_ioctl.c8
4 files changed, 57 insertions, 25 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index b3ac40aef46b..89b97b5e0881 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -97,19 +97,22 @@ void blk_recalc_rq_segments(struct request *rq)
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
- bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
- &q->queue_flags);
- bool merge_not_need = bio->bi_vcnt < queue_max_segments(q);
+ unsigned short seg_cnt;
+
+ /* estimate segment number by bi_vcnt for non-cloned bio */
+ if (bio_flagged(bio, BIO_CLONED))
+ seg_cnt = bio_segments(bio);
+ else
+ seg_cnt = bio->bi_vcnt;
- if (no_sg_merge && !bio_flagged(bio, BIO_CLONED) &&
- merge_not_need)
- bio->bi_phys_segments = bio->bi_vcnt;
+ if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
+ (seg_cnt < queue_max_segments(q)))
+ bio->bi_phys_segments = seg_cnt;
else {
struct bio *nxt = bio->bi_next;
bio->bi_next = NULL;
- bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio,
- no_sg_merge && merge_not_need);
+ bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
bio->bi_next = nxt;
}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 68929bad9a6a..1d016fc9a8b6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -107,11 +107,7 @@ static void blk_mq_usage_counter_release(struct percpu_ref *ref)
wake_up_all(&q->mq_freeze_wq);
}
-/*
- * Guarantee no request is in use, so we can change any data structure of
- * the queue afterward.
- */
-void blk_mq_freeze_queue(struct request_queue *q)
+static void blk_mq_freeze_queue_start(struct request_queue *q)
{
bool freeze;
@@ -123,9 +119,23 @@ void blk_mq_freeze_queue(struct request_queue *q)
percpu_ref_kill(&q->mq_usage_counter);
blk_mq_run_queues(q, false);
}
+}
+
+static void blk_mq_freeze_queue_wait(struct request_queue *q)
+{
wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter));
}
+/*
+ * Guarantee no request is in use, so we can change any data structure of
+ * the queue afterward.
+ */
+void blk_mq_freeze_queue(struct request_queue *q)
+{
+ blk_mq_freeze_queue_start(q);
+ blk_mq_freeze_queue_wait(q);
+}
+
static void blk_mq_unfreeze_queue(struct request_queue *q)
{
bool wake;
@@ -1921,7 +1931,7 @@ void blk_mq_free_queue(struct request_queue *q)
/* Basically redo blk_mq_init_queue with queue frozen */
static void blk_mq_queue_reinit(struct request_queue *q)
{
- blk_mq_freeze_queue(q);
+ WARN_ON_ONCE(!q->mq_freeze_depth);
blk_mq_sysfs_unregister(q);
@@ -1936,8 +1946,6 @@ static void blk_mq_queue_reinit(struct request_queue *q)
blk_mq_map_swqueue(q);
blk_mq_sysfs_register(q);
-
- blk_mq_unfreeze_queue(q);
}
static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
@@ -1956,8 +1964,25 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
return NOTIFY_OK;
mutex_lock(&all_q_mutex);
+
+ /*
+ * We need to freeze and reinit all existing queues. Freezing
+ * involves synchronous wait for an RCU grace period and doing it
+ * one by one may take a long time. Start freezing all queues in
+ * one swoop and then wait for the completions so that freezing can
+ * take place in parallel.
+ */
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ blk_mq_freeze_queue_start(q);
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ blk_mq_freeze_queue_wait(q);
+
list_for_each_entry(q, &all_q_list, all_q_node)
blk_mq_queue_reinit(q);
+
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ blk_mq_unfreeze_queue(q);
+
mutex_unlock(&all_q_mutex);
return NOTIFY_OK;
}
diff --git a/block/ioprio.c b/block/ioprio.c
index e50170ca7c33..31666c92b46a 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -157,14 +157,16 @@ out:
int ioprio_best(unsigned short aprio, unsigned short bprio)
{
- unsigned short aclass = IOPRIO_PRIO_CLASS(aprio);
- unsigned short bclass = IOPRIO_PRIO_CLASS(bprio);
+ unsigned short aclass;
+ unsigned short bclass;
- if (aclass == IOPRIO_CLASS_NONE)
- aclass = IOPRIO_CLASS_BE;
- if (bclass == IOPRIO_CLASS_NONE)
- bclass = IOPRIO_CLASS_BE;
+ if (!ioprio_valid(aprio))
+ aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
+ if (!ioprio_valid(bprio))
+ bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
+ aclass = IOPRIO_PRIO_CLASS(aprio);
+ bclass = IOPRIO_PRIO_CLASS(bprio);
if (aclass == bclass)
return min(aprio, bprio);
if (aclass > bclass)
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 1e053d911240..b0c2a616c8f9 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -458,7 +458,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
- goto error;
+ goto error_free_buffer;
}
blk_rq_set_block_pc(rq);
@@ -531,9 +531,11 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
}
error:
+ blk_put_request(rq);
+
+error_free_buffer:
kfree(buffer);
- if (rq)
- blk_put_request(rq);
+
return err;
}
EXPORT_SYMBOL_GPL(sg_scsi_ioctl);

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