#include <linux/backing-dev.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
+#include <linux/kmemleak.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/slab.h>
clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
}
-static int blk_mq_queue_enter(struct request_queue *q, gfp_t gfp)
-{
- while (true) {
- int ret;
-
- if (percpu_ref_tryget_live(&q->mq_usage_counter))
- return 0;
-
- if (!(gfp & __GFP_WAIT))
- return -EBUSY;
-
- ret = swait_event_interruptible(q->mq_freeze_wq,
- !q->mq_freeze_depth || blk_queue_dying(q));
- if (blk_queue_dying(q))
- return -ENODEV;
- if (ret)
- return ret;
- }
-}
-
-static void blk_mq_queue_exit(struct request_queue *q)
-{
- percpu_ref_put(&q->mq_usage_counter);
-}
-
-static void blk_mq_usage_counter_release(struct percpu_ref *ref)
-{
- struct request_queue *q =
- container_of(ref, struct request_queue, mq_usage_counter);
-
- swait_wake_all(&q->mq_freeze_wq);
-}
-
void blk_mq_freeze_queue_start(struct request_queue *q)
{
- bool freeze;
+ int freeze_depth;
- spin_lock_irq(q->queue_lock);
- freeze = !q->mq_freeze_depth++;
- spin_unlock_irq(q->queue_lock);
-
- if (freeze) {
- percpu_ref_kill(&q->mq_usage_counter);
+ freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
+ if (freeze_depth == 1) {
+ percpu_ref_kill(&q->q_usage_counter);
blk_mq_run_hw_queues(q, false);
}
}
static void blk_mq_freeze_queue_wait(struct request_queue *q)
{
- swait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter));
+ swait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_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)
+void blk_freeze_queue(struct request_queue *q)
{
+ /*
+ * In the !blk_mq case we are only calling this to kill the
+ * q_usage_counter, otherwise this increases the freeze depth
+ * and waits for it to return to zero. For this reason there is
+ * no blk_unfreeze_queue(), and blk_freeze_queue() is not
+ * exported to drivers as the only user for unfreeze is blk_mq.
+ */
blk_mq_freeze_queue_start(q);
blk_mq_freeze_queue_wait(q);
}
+
+void blk_mq_freeze_queue(struct request_queue *q)
+{
+ /*
+ * ...just an alias to keep freeze and unfreeze actions balanced
+ * in the blk_mq_* namespace
+ */
+ blk_freeze_queue(q);
+}
EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
void blk_mq_unfreeze_queue(struct request_queue *q)
{
- bool wake;
+ int freeze_depth;
- spin_lock_irq(q->queue_lock);
- wake = !--q->mq_freeze_depth;
- WARN_ON_ONCE(q->mq_freeze_depth < 0);
- spin_unlock_irq(q->queue_lock);
- if (wake) {
- percpu_ref_reinit(&q->mq_usage_counter);
- swait_wake_all(&q->mq_freeze_wq);
+ freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
+ WARN_ON_ONCE(freeze_depth < 0);
+ if (!freeze_depth) {
+ percpu_ref_reinit(&q->q_usage_counter);
+ swake_up_all(&q->mq_freeze_wq);
}
}
EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
* dying, we need to ensure that processes currently waiting on
* the queue are notified as well.
*/
- swait_wake_all(&q->mq_freeze_wq);
+ swake_up_all(&q->mq_freeze_wq);
}
bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
struct blk_mq_alloc_data alloc_data;
int ret;
- ret = blk_mq_queue_enter(q, gfp);
+ ret = blk_queue_enter(q, gfp);
if (ret)
return ERR_PTR(ret);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT,
+ blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_DIRECT_RECLAIM,
reserved, ctx, hctx);
rq = __blk_mq_alloc_request(&alloc_data, rw);
- if (!rq && (gfp & __GFP_WAIT)) {
+ if (!rq && (gfp & __GFP_DIRECT_RECLAIM)) {
__blk_mq_run_hw_queue(hctx);
blk_mq_put_ctx(ctx);
}
blk_mq_put_ctx(ctx);
if (!rq) {
- blk_mq_queue_exit(q);
+ blk_queue_exit(q);
return ERR_PTR(-EWOULDBLOCK);
}
return rq;
clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
blk_mq_put_tag(hctx, tag, &ctx->last_tag);
- blk_mq_queue_exit(q);
+ blk_queue_exit(q);
}
void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
put_cpu_light();
}
-void __blk_mq_complete_request(struct request *rq)
+static void __blk_mq_complete_request(struct request *rq)
{
struct request_queue *q = rq->q;
* Ends all I/O on a request. It does not handle partial completions.
* The actual completion happens out-of-order, through a IPI handler.
**/
-void blk_mq_complete_request(struct request *rq)
+void blk_mq_complete_request(struct request *rq, int error)
{
struct request_queue *q = rq->q;
if (unlikely(blk_should_fake_timeout(q)))
return;
- if (!blk_mark_rq_complete(rq))
+ if (!blk_mark_rq_complete(rq)) {
+ rq->errors = error;
__blk_mq_complete_request(rq);
+ }
}
EXPORT_SYMBOL(blk_mq_complete_request);
}
EXPORT_SYMBOL(blk_mq_abort_requeue_list);
-static inline bool is_flush_request(struct request *rq,
- struct blk_flush_queue *fq, unsigned int tag)
-{
- return ((rq->cmd_flags & REQ_FLUSH_SEQ) &&
- fq->flush_rq->tag == tag);
-}
-
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
{
- struct request *rq = tags->rqs[tag];
- /* mq_ctx of flush rq is always cloned from the corresponding req */
- struct blk_flush_queue *fq = blk_get_flush_queue(rq->q, rq->mq_ctx);
-
- if (!is_flush_request(rq, fq, tag))
- return rq;
-
- return fq->flush_rq;
+ return tags->rqs[tag];
}
EXPORT_SYMBOL(blk_mq_tag_to_rq);
* If a request wasn't started before the queue was
* marked dying, kill it here or it'll go unnoticed.
*/
- if (unlikely(blk_queue_dying(rq->q))) {
- rq->errors = -EIO;
- blk_mq_complete_request(rq);
- }
+ if (unlikely(blk_queue_dying(rq->q)))
+ blk_mq_complete_request(rq, -EIO);
return;
}
if (rq->cmd_flags & REQ_NO_TIMEOUT)
.next = 0,
.next_set = 0,
};
- struct blk_mq_hw_ctx *hctx;
int i;
- queue_for_each_hw_ctx(q, hctx, i) {
- /*
- * If not software queues are currently mapped to this
- * hardware queue, there's nothing to check
- */
- if (!blk_mq_hw_queue_mapped(hctx))
- continue;
-
- blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data);
- }
+ blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
if (data.next_set) {
data.next = blk_rq_timeout(round_jiffies_up(data.next));
mod_timer(&q->timeout, data.next);
} else {
+ struct blk_mq_hw_ctx *hctx;
+
queue_for_each_hw_ctx(q, hctx, i) {
/* the hctx may be unmapped, so check it here */
if (blk_mq_hw_queue_mapped(hctx))
}
EXPORT_SYMBOL(blk_mq_delay_queue);
-static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
- struct request *rq, bool at_head)
+static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx,
+ struct request *rq,
+ bool at_head)
{
- struct blk_mq_ctx *ctx = rq->mq_ctx;
-
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
list_add(&rq->queuelist, &ctx->rq_list);
else
list_add_tail(&rq->queuelist, &ctx->rq_list);
+}
+
+static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, bool at_head)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
rq = list_first_entry(list, struct request, queuelist);
list_del_init(&rq->queuelist);
rq->mq_ctx = ctx;
- __blk_mq_insert_request(hctx, rq, false);
+ __blk_mq_insert_req_list(hctx, ctx, rq, false);
}
+ blk_mq_hctx_mark_pending(hctx, ctx);
spin_unlock(&ctx->lock);
blk_mq_run_hw_queue(hctx, from_schedule);
struct blk_mq_ctx *ctx,
struct request *rq, struct bio *bio)
{
- if (!hctx_allow_merges(hctx)) {
+ if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
blk_mq_bio_to_request(rq, bio);
spin_lock(&ctx->lock);
insert_rq:
int rw = bio_data_dir(bio);
struct blk_mq_alloc_data alloc_data;
- if (unlikely(blk_mq_queue_enter(q, GFP_KERNEL))) {
- bio_endio(bio, -EIO);
- return NULL;
- }
-
+ blk_queue_enter_live(q);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q,
- __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx);
+ __GFP_RECLAIM|__GFP_HIGH, false, ctx, hctx);
rq = __blk_mq_alloc_request(&alloc_data, rw);
ctx = alloc_data.ctx;
hctx = alloc_data.hctx;
return rq;
}
+static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
+{
+ int ret;
+ struct request_queue *q = rq->q;
+ struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q,
+ rq->mq_ctx->cpu);
+ struct blk_mq_queue_data bd = {
+ .rq = rq,
+ .list = NULL,
+ .last = 1
+ };
+ blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
+
+ /*
+ * For OK queue, we are done. For error, kill it. Any other
+ * error (busy), just add it to our list as we previously
+ * would have done
+ */
+ ret = q->mq_ops->queue_rq(hctx, &bd);
+ if (ret == BLK_MQ_RQ_QUEUE_OK) {
+ *cookie = new_cookie;
+ return 0;
+ }
+
+ __blk_mq_requeue_request(rq);
+
+ if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
+ *cookie = BLK_QC_T_NONE;
+ rq->errors = -EIO;
+ blk_mq_end_request(rq, rq->errors);
+ return 0;
+ }
+
+ return -1;
+}
+
/*
* Multiple hardware queue variant. This will not use per-process plugs,
* but will attempt to bypass the hctx queueing if we can go straight to
* hardware for SYNC IO.
*/
-static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
const int is_sync = rw_is_sync(bio->bi_rw);
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
struct blk_map_ctx data;
struct request *rq;
+ unsigned int request_count = 0;
+ struct blk_plug *plug;
+ struct request *same_queue_rq = NULL;
+ blk_qc_t cookie;
blk_queue_bounce(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
- bio_endio(bio, -EIO);
- return;
+ bio_io_error(bio);
+ return BLK_QC_T_NONE;
}
+ blk_queue_split(q, &bio, q->bio_split);
+
+ if (!is_flush_fua && !blk_queue_nomerges(q)) {
+ if (blk_attempt_plug_merge(q, bio, &request_count,
+ &same_queue_rq))
+ return BLK_QC_T_NONE;
+ } else
+ request_count = blk_plug_queued_count(q);
+
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
- return;
+ return BLK_QC_T_NONE;
+
+ cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
if (unlikely(is_flush_fua)) {
blk_mq_bio_to_request(rq, bio);
goto run_queue;
}
+ plug = current->plug;
/*
* If the driver supports defer issued based on 'last', then
* queue it up like normal since we can potentially save some
* CPU this way.
*/
- if (is_sync && !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
- struct blk_mq_queue_data bd = {
- .rq = rq,
- .list = NULL,
- .last = 1
- };
- int ret;
+ if (((plug && !blk_queue_nomerges(q)) || is_sync) &&
+ !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
+ struct request *old_rq = NULL;
blk_mq_bio_to_request(rq, bio);
/*
- * For OK queue, we are done. For error, kill it. Any other
- * error (busy), just add it to our list as we previously
- * would have done
+ * We do limited pluging. If the bio can be merged, do that.
+ * Otherwise the existing request in the plug list will be
+ * issued. So the plug list will have one request at most
*/
- ret = q->mq_ops->queue_rq(data.hctx, &bd);
- if (ret == BLK_MQ_RQ_QUEUE_OK)
- goto done;
- else {
- __blk_mq_requeue_request(rq);
-
- if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
- rq->errors = -EIO;
- blk_mq_end_request(rq, rq->errors);
- goto done;
+ if (plug) {
+ /*
+ * The plug list might get flushed before this. If that
+ * happens, same_queue_rq is invalid and plug list is
+ * empty
+ */
+ if (same_queue_rq && !list_empty(&plug->mq_list)) {
+ old_rq = same_queue_rq;
+ list_del_init(&old_rq->queuelist);
}
- }
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+ } else /* is_sync */
+ old_rq = rq;
+ blk_mq_put_ctx(data.ctx);
+ if (!old_rq)
+ goto done;
+ if (!blk_mq_direct_issue_request(old_rq, &cookie))
+ goto done;
+ blk_mq_insert_request(old_rq, false, true, true);
+ goto done;
}
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
run_queue:
blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
}
-done:
blk_mq_put_ctx(data.ctx);
+done:
+ return cookie;
}
/*
* Single hardware queue variant. This will attempt to use any per-process
* plug for merging and IO deferral.
*/
-static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
+static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
{
const int is_sync = rw_is_sync(bio->bi_rw);
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
- unsigned int use_plug, request_count = 0;
+ struct blk_plug *plug;
+ unsigned int request_count = 0;
struct blk_map_ctx data;
struct request *rq;
-
- /*
- * If we have multiple hardware queues, just go directly to
- * one of those for sync IO.
- */
- use_plug = !is_flush_fua && !is_sync;
+ blk_qc_t cookie;
blk_queue_bounce(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
- bio_endio(bio, -EIO);
- return;
+ bio_io_error(bio);
+ return BLK_QC_T_NONE;
}
- if (use_plug && !blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count))
- return;
+ blk_queue_split(q, &bio, q->bio_split);
+
+ if (!is_flush_fua && !blk_queue_nomerges(q) &&
+ blk_attempt_plug_merge(q, bio, &request_count, NULL))
+ return BLK_QC_T_NONE;
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
- return;
+ return BLK_QC_T_NONE;
+
+ cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
if (unlikely(is_flush_fua)) {
blk_mq_bio_to_request(rq, bio);
* utilize that to temporarily store requests until the task is
* either done or scheduled away.
*/
- if (use_plug) {
- struct blk_plug *plug = current->plug;
+ plug = current->plug;
+ if (plug) {
+ blk_mq_bio_to_request(rq, bio);
+ if (!request_count)
+ trace_block_plug(q);
- if (plug) {
- blk_mq_bio_to_request(rq, bio);
- if (list_empty(&plug->mq_list))
- trace_block_plug(q);
- else if (request_count >= BLK_MAX_REQUEST_COUNT) {
- blk_flush_plug_list(plug, false);
- trace_block_plug(q);
- }
- list_add_tail(&rq->queuelist, &plug->mq_list);
- blk_mq_put_ctx(data.ctx);
- return;
+ blk_mq_put_ctx(data.ctx);
+
+ if (request_count >= BLK_MAX_REQUEST_COUNT) {
+ blk_flush_plug_list(plug, false);
+ trace_block_plug(q);
}
+
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+ return cookie;
}
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
}
blk_mq_put_ctx(data.ctx);
+ return cookie;
}
/*
while (!list_empty(&tags->page_list)) {
page = list_first_entry(&tags->page_list, struct page, lru);
list_del_init(&page->lru);
+ /*
+ * Remove kmemleak object previously allocated in
+ * blk_mq_init_rq_map().
+ */
+ kmemleak_free(page_address(page));
__free_pages(page, page->private);
}
list_add_tail(&page->lru, &tags->page_list);
p = page_address(page);
+ /*
+ * Allow kmemleak to scan these pages as they contain pointers
+ * to additional allocations like via ops->init_request().
+ */
+ kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
entries_per_page = order_to_size(this_order) / rq_size;
to_do = min(entries_per_page, set->queue_depth - i);
left -= to_do * rq_size;
i++;
}
}
-
return tags;
fail:
INIT_LIST_HEAD(&hctx->dispatch);
hctx->queue = q;
hctx->queue_num = hctx_idx;
- hctx->flags = set->flags;
+ hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
blk_mq_hctx_notify, hctx);
}
}
-static void blk_mq_map_swqueue(struct request_queue *q)
+static void blk_mq_map_swqueue(struct request_queue *q,
+ const struct cpumask *online_mask)
{
unsigned int i;
struct blk_mq_hw_ctx *hctx;
struct blk_mq_ctx *ctx;
struct blk_mq_tag_set *set = q->tag_set;
+ /*
+ * Avoid others reading imcomplete hctx->cpumask through sysfs
+ */
+ mutex_lock(&q->sysfs_lock);
+
queue_for_each_hw_ctx(q, hctx, i) {
cpumask_clear(hctx->cpumask);
hctx->nr_ctx = 0;
*/
queue_for_each_ctx(q, ctx, i) {
/* If the cpu isn't online, the cpu is mapped to first hctx */
- if (!cpu_online(i))
+ if (!cpumask_test_cpu(i, online_mask))
continue;
hctx = q->mq_ops->map_queue(q, i);
hctx->ctxs[hctx->nr_ctx++] = ctx;
}
+ mutex_unlock(&q->sysfs_lock);
+
queue_for_each_hw_ctx(q, hctx, i) {
struct blk_mq_ctxmap *map = &hctx->ctx_map;
hctx->next_cpu = cpumask_first(hctx->cpumask);
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
}
+
+ queue_for_each_ctx(q, ctx, i) {
+ if (!cpumask_test_cpu(i, online_mask))
+ continue;
+
+ hctx = q->mq_ops->map_queue(q, i);
+ cpumask_set_cpu(i, hctx->tags->cpumask);
+ }
}
-static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set)
+static void queue_set_hctx_shared(struct request_queue *q, bool shared)
{
struct blk_mq_hw_ctx *hctx;
- struct request_queue *q;
- bool shared;
int i;
- if (set->tag_list.next == set->tag_list.prev)
- shared = false;
- else
- shared = true;
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (shared)
+ hctx->flags |= BLK_MQ_F_TAG_SHARED;
+ else
+ hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+ }
+}
+
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
+{
+ struct request_queue *q;
list_for_each_entry(q, &set->tag_list, tag_set_list) {
blk_mq_freeze_queue(q);
-
- queue_for_each_hw_ctx(q, hctx, i) {
- if (shared)
- hctx->flags |= BLK_MQ_F_TAG_SHARED;
- else
- hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
- }
+ queue_set_hctx_shared(q, shared);
blk_mq_unfreeze_queue(q);
}
}
mutex_lock(&set->tag_list_lock);
list_del_init(&q->tag_set_list);
- blk_mq_update_tag_set_depth(set);
+ if (list_is_singular(&set->tag_list)) {
+ /* just transitioned to unshared */
+ set->flags &= ~BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, false);
+ }
mutex_unlock(&set->tag_list_lock);
}
q->tag_set = set;
mutex_lock(&set->tag_list_lock);
+
+ /* Check to see if we're transitioning to shared (from 1 to 2 queues). */
+ if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
+ set->flags |= BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, true);
+ }
+ if (set->flags & BLK_MQ_F_TAG_SHARED)
+ queue_set_hctx_shared(q, true);
list_add_tail(&q->tag_set_list, &set->tag_list);
- blk_mq_update_tag_set_depth(set);
+
mutex_unlock(&set->tag_list_lock);
}
kfree(hctx);
}
+ kfree(q->mq_map);
+ q->mq_map = NULL;
+
kfree(q->queue_hw_ctx);
/* ctx kobj stays in queue_ctx */
hctxs[i]->queue_num = i;
}
- /*
- * Init percpu_ref in atomic mode so that it's faster to shutdown.
- * See blk_register_queue() for details.
- */
- if (percpu_ref_init(&q->mq_usage_counter, blk_mq_usage_counter_release,
- PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
- goto err_hctxs;
-
setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);
blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
if (blk_mq_init_hw_queues(q, set))
goto err_hctxs;
+ get_online_cpus();
mutex_lock(&all_q_mutex);
- list_add_tail(&q->all_q_node, &all_q_list);
- mutex_unlock(&all_q_mutex);
+ list_add_tail(&q->all_q_node, &all_q_list);
blk_mq_add_queue_tag_set(set, q);
+ blk_mq_map_swqueue(q, cpu_online_mask);
- blk_mq_map_swqueue(q);
+ mutex_unlock(&all_q_mutex);
+ put_online_cpus();
return q;
{
struct blk_mq_tag_set *set = q->tag_set;
+ mutex_lock(&all_q_mutex);
+ list_del_init(&q->all_q_node);
+ mutex_unlock(&all_q_mutex);
+
blk_mq_del_queue_tag_set(q);
blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
blk_mq_free_hw_queues(q, set);
-
- percpu_ref_exit(&q->mq_usage_counter);
-
- kfree(q->mq_map);
-
- q->mq_map = NULL;
-
- mutex_lock(&all_q_mutex);
- list_del_init(&q->all_q_node);
- mutex_unlock(&all_q_mutex);
}
/* Basically redo blk_mq_init_queue with queue frozen */
-static void blk_mq_queue_reinit(struct request_queue *q)
+static void blk_mq_queue_reinit(struct request_queue *q,
+ const struct cpumask *online_mask)
{
- WARN_ON_ONCE(!q->mq_freeze_depth);
+ WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
blk_mq_sysfs_unregister(q);
- blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues);
+ blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask);
/*
* redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
* involves free and re-allocate memory, worthy doing?)
*/
- blk_mq_map_swqueue(q);
+ blk_mq_map_swqueue(q, online_mask);
blk_mq_sysfs_register(q);
}
unsigned long action, void *hcpu)
{
struct request_queue *q;
+ int cpu = (unsigned long)hcpu;
+ /*
+ * New online cpumask which is going to be set in this hotplug event.
+ * Declare this cpumasks as global as cpu-hotplug operation is invoked
+ * one-by-one and dynamically allocating this could result in a failure.
+ */
+ static struct cpumask online_new;
/*
- * Before new mappings are established, hotadded cpu might already
- * start handling requests. This doesn't break anything as we map
- * offline CPUs to first hardware queue. We will re-init the queue
- * below to get optimal settings.
+ * Before hotadded cpu starts handling requests, new mappings must
+ * be established. Otherwise, these requests in hw queue might
+ * never be dispatched.
+ *
+ * For example, there is a single hw queue (hctx) and two CPU queues
+ * (ctx0 for CPU0, and ctx1 for CPU1).
+ *
+ * Now CPU1 is just onlined and a request is inserted into
+ * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is
+ * still zero.
+ *
+ * And then while running hw queue, flush_busy_ctxs() finds bit0 is
+ * set in pending bitmap and tries to retrieve requests in
+ * hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0,
+ * so the request in ctx1->rq_list is ignored.
*/
- if (action != CPU_DEAD && action != CPU_DEAD_FROZEN &&
- action != CPU_ONLINE && action != CPU_ONLINE_FROZEN)
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_DEAD:
+ case CPU_UP_CANCELED:
+ cpumask_copy(&online_new, cpu_online_mask);
+ break;
+ case CPU_UP_PREPARE:
+ cpumask_copy(&online_new, cpu_online_mask);
+ cpumask_set_cpu(cpu, &online_new);
+ break;
+ default:
return NOTIFY_OK;
+ }
mutex_lock(&all_q_mutex);
}
list_for_each_entry(q, &all_q_list, all_q_node)
- blk_mq_queue_reinit(q);
+ blk_mq_queue_reinit(q, &online_new);
list_for_each_entry(q, &all_q_list, all_q_node)
blk_mq_unfreeze_queue(q);
return 0;
}
+struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags)
+{
+ return tags->cpumask;
+}
+EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask);
+
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
Code Review / kvmfornfv.git / blobdiff