*/
void blk_drain_queue(struct request_queue *q, bool drain_all)
{
+ int i;
+
while (true) {
bool drain = false;
- int i;
spin_lock_irq(q->queue_lock);
if (!list_empty(&q->queue_head) && q->request_fn)
__blk_run_queue(q);
- drain |= q->rq.elvpriv;
+ drain |= q->nr_rqs_elvpriv;
/*
* Unfortunately, requests are queued at and tracked from
if (drain_all) {
drain |= !list_empty(&q->queue_head);
for (i = 0; i < 2; i++) {
- drain |= q->rq.count[i];
+ drain |= q->nr_rqs[i];
drain |= q->in_flight[i];
drain |= !list_empty(&q->flush_queue[i]);
}
break;
msleep(10);
}
+
+ /*
+ * With queue marked dead, any woken up waiter will fail the
+ * allocation path, so the wakeup chaining is lost and we're
+ * left with hung waiters. We need to wake up those waiters.
+ */
+ if (q->request_fn) {
+ spin_lock_irq(q->queue_lock);
+ for (i = 0; i < ARRAY_SIZE(q->rq.wait); i++)
+ wake_up_all(&q->rq.wait[i]);
+ spin_unlock_irq(q->queue_lock);
+ }
}
/**
/* mark @q DEAD, no new request or merges will be allowed afterwards */
mutex_lock(&q->sysfs_lock);
queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
-
spin_lock_irq(lock);
/*
queue_flag_set(QUEUE_FLAG_NOMERGES, q);
queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
queue_flag_set(QUEUE_FLAG_DEAD, q);
-
- if (q->queue_lock != &q->__queue_lock)
- q->queue_lock = &q->__queue_lock;
-
spin_unlock_irq(lock);
mutex_unlock(&q->sysfs_lock);
del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
blk_sync_queue(q);
+ spin_lock_irq(lock);
+ if (q->queue_lock != &q->__queue_lock)
+ q->queue_lock = &q->__queue_lock;
+ spin_unlock_irq(lock);
+
/* @q is and will stay empty, shutdown and put */
blk_put_queue(q);
}
EXPORT_SYMBOL(blk_cleanup_queue);
-static int blk_init_free_list(struct request_queue *q)
+int blk_init_rl(struct request_list *rl, struct request_queue *q,
+ gfp_t gfp_mask)
{
- struct request_list *rl = &q->rq;
-
if (unlikely(rl->rq_pool))
return 0;
+ rl->q = q;
rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0;
rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0;
- rl->elvpriv = 0;
init_waitqueue_head(&rl->wait[BLK_RW_SYNC]);
init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]);
rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
- mempool_free_slab, request_cachep, q->node);
-
+ mempool_free_slab, request_cachep,
+ gfp_mask, q->node);
if (!rl->rq_pool)
return -ENOMEM;
return 0;
}
+void blk_exit_rl(struct request_list *rl)
+{
+ if (rl->rq_pool)
+ mempool_destroy(rl->rq_pool);
+}
+
struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
{
return blk_alloc_queue_node(gfp_mask, -1);
if (!q)
return NULL;
- if (blk_init_free_list(q))
+ if (blk_init_rl(&q->rq, q, GFP_KERNEL))
return NULL;
q->request_fn = rfn;
}
EXPORT_SYMBOL(blk_get_queue);
-static inline void blk_free_request(struct request_queue *q, struct request *rq)
+static inline void blk_free_request(struct request_list *rl, struct request *rq)
{
if (rq->cmd_flags & REQ_ELVPRIV) {
- elv_put_request(q, rq);
+ elv_put_request(rl->q, rq);
if (rq->elv.icq)
put_io_context(rq->elv.icq->ioc);
}
- mempool_free(rq, q->rq.rq_pool);
+ mempool_free(rq, rl->rq_pool);
}
/*
ioc->last_waited = jiffies;
}
-static void __freed_request(struct request_queue *q, int sync)
+static void __freed_request(struct request_list *rl, int sync)
{
- struct request_list *rl = &q->rq;
+ struct request_queue *q = rl->q;
if (rl->count[sync] < queue_congestion_off_threshold(q))
blk_clear_queue_congested(q, sync);
if (waitqueue_active(&rl->wait[sync]))
wake_up(&rl->wait[sync]);
- blk_clear_queue_full(q, sync);
+ blk_clear_rl_full(rl, sync);
}
}
* A request has just been released. Account for it, update the full and
* congestion status, wake up any waiters. Called under q->queue_lock.
*/
-static void freed_request(struct request_queue *q, unsigned int flags)
+static void freed_request(struct request_list *rl, unsigned int flags)
{
- struct request_list *rl = &q->rq;
+ struct request_queue *q = rl->q;
int sync = rw_is_sync(flags);
+ q->nr_rqs[sync]--;
rl->count[sync]--;
if (flags & REQ_ELVPRIV)
- rl->elvpriv--;
+ q->nr_rqs_elvpriv--;
- __freed_request(q, sync);
+ __freed_request(rl, sync);
if (unlikely(rl->starved[sync ^ 1]))
- __freed_request(q, sync ^ 1);
+ __freed_request(rl, sync ^ 1);
}
/*
}
/**
- * get_request - get a free request
- * @q: request_queue to allocate request from
+ * __get_request - get a free request
+ * @rl: request list to allocate from
* @rw_flags: RW and SYNC flags
* @bio: bio to allocate request for (can be %NULL)
* @gfp_mask: allocation mask
* Returns %NULL on failure, with @q->queue_lock held.
* Returns !%NULL on success, with @q->queue_lock *not held*.
*/
-static struct request *get_request(struct request_queue *q, int rw_flags,
- struct bio *bio, gfp_t gfp_mask)
+static struct request *__get_request(struct request_list *rl, int rw_flags,
+ struct bio *bio, gfp_t gfp_mask)
{
+ struct request_queue *q = rl->q;
struct request *rq;
- struct request_list *rl = &q->rq;
- struct elevator_type *et;
- struct io_context *ioc;
+ struct elevator_type *et = q->elevator->type;
+ struct io_context *ioc = rq_ioc(bio);
struct io_cq *icq = NULL;
const bool is_sync = rw_is_sync(rw_flags) != 0;
- bool retried = false;
int may_queue;
-retry:
- et = q->elevator->type;
- ioc = rq_ioc(bio);
if (unlikely(blk_queue_dead(q)))
return NULL;
if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) {
if (rl->count[is_sync]+1 >= q->nr_requests) {
- /*
- * We want ioc to record batching state. If it's
- * not already there, creating a new one requires
- * dropping queue_lock, which in turn requires
- * retesting conditions to avoid queue hang.
- */
- if (!ioc && !retried) {
- spin_unlock_irq(q->queue_lock);
- create_io_context(gfp_mask, q->node);
- spin_lock_irq(q->queue_lock);
- retried = true;
- goto retry;
- }
-
/*
* The queue will fill after this allocation, so set
* it as full, and mark this process as "batching".
* This process will be allowed to complete a batch of
* requests, others will be blocked.
*/
- if (!blk_queue_full(q, is_sync)) {
+ if (!blk_rl_full(rl, is_sync)) {
ioc_set_batching(q, ioc);
- blk_set_queue_full(q, is_sync);
+ blk_set_rl_full(rl, is_sync);
} else {
if (may_queue != ELV_MQUEUE_MUST
&& !ioc_batching(q, ioc)) {
if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
return NULL;
+ q->nr_rqs[is_sync]++;
rl->count[is_sync]++;
rl->starved[is_sync] = 0;
*/
if (blk_rq_should_init_elevator(bio) && !blk_queue_bypass(q)) {
rw_flags |= REQ_ELVPRIV;
- rl->elvpriv++;
+ q->nr_rqs_elvpriv++;
if (et->icq_cache && ioc)
icq = ioc_lookup_icq(ioc, q);
}
spin_unlock_irq(q->queue_lock);
/* allocate and init request */
- rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
+ rq = mempool_alloc(rl->rq_pool, gfp_mask);
if (!rq)
goto fail_alloc;
/* init elvpriv */
if (rw_flags & REQ_ELVPRIV) {
if (unlikely(et->icq_cache && !icq)) {
- create_io_context(gfp_mask, q->node);
- ioc = rq_ioc(bio);
- if (!ioc)
- goto fail_elvpriv;
-
- icq = ioc_create_icq(ioc, q, gfp_mask);
+ if (ioc)
+ icq = ioc_create_icq(ioc, q, gfp_mask);
if (!icq)
goto fail_elvpriv;
}
rq->elv.icq = NULL;
spin_lock_irq(q->queue_lock);
- rl->elvpriv--;
+ q->nr_rqs_elvpriv--;
spin_unlock_irq(q->queue_lock);
goto out;
* queue, but this is pretty rare.
*/
spin_lock_irq(q->queue_lock);
- freed_request(q, rw_flags);
+ freed_request(rl, rw_flags);
/*
* in the very unlikely event that allocation failed and no
}
/**
- * get_request_wait - get a free request with retry
+ * get_request - get a free request
* @q: request_queue to allocate request from
* @rw_flags: RW and SYNC flags
* @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
*
- * Get a free request from @q. This function keeps retrying under memory
- * pressure and fails iff @q is dead.
+ * Get a free request from @q. If %__GFP_WAIT is set in @gfp_mask, this
+ * function keeps retrying under memory pressure and fails iff @q is dead.
*
* Must be callled with @q->queue_lock held and,
* Returns %NULL on failure, with @q->queue_lock held.
* Returns !%NULL on success, with @q->queue_lock *not held*.
*/
-static struct request *get_request_wait(struct request_queue *q, int rw_flags,
- struct bio *bio)
+static struct request *get_request(struct request_queue *q, int rw_flags,
+ struct bio *bio, gfp_t gfp_mask)
{
const bool is_sync = rw_is_sync(rw_flags) != 0;
+ DEFINE_WAIT(wait);
+ struct request_list *rl = &q->rq;
struct request *rq;
+retry:
+ rq = __get_request(&q->rq, rw_flags, bio, gfp_mask);
+ if (rq)
+ return rq;
- rq = get_request(q, rw_flags, bio, GFP_NOIO);
- while (!rq) {
- DEFINE_WAIT(wait);
- struct request_list *rl = &q->rq;
-
- if (unlikely(blk_queue_dead(q)))
- return NULL;
-
- prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
- TASK_UNINTERRUPTIBLE);
+ if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dead(q)))
+ return NULL;
- trace_block_sleeprq(q, bio, rw_flags & 1);
+ /* wait on @rl and retry */
+ prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
+ TASK_UNINTERRUPTIBLE);
- spin_unlock_irq(q->queue_lock);
- io_schedule();
+ trace_block_sleeprq(q, bio, rw_flags & 1);
- /*
- * After sleeping, we become a "batching" process and
- * will be able to allocate at least one request, and
- * up to a big batch of them for a small period time.
- * See ioc_batching, ioc_set_batching
- */
- create_io_context(GFP_NOIO, q->node);
- ioc_set_batching(q, current->io_context);
+ spin_unlock_irq(q->queue_lock);
+ io_schedule();
- spin_lock_irq(q->queue_lock);
- finish_wait(&rl->wait[is_sync], &wait);
+ /*
+ * After sleeping, we become a "batching" process and will be able
+ * to allocate at least one request, and up to a big batch of them
+ * for a small period time. See ioc_batching, ioc_set_batching
+ */
+ ioc_set_batching(q, current->io_context);
- rq = get_request(q, rw_flags, bio, GFP_NOIO);
- };
+ spin_lock_irq(q->queue_lock);
+ finish_wait(&rl->wait[is_sync], &wait);
- return rq;
+ goto retry;
}
struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
BUG_ON(rw != READ && rw != WRITE);
+ /* create ioc upfront */
+ create_io_context(gfp_mask, q->node);
+
spin_lock_irq(q->queue_lock);
- if (gfp_mask & __GFP_WAIT)
- rq = get_request_wait(q, rw, NULL);
- else
- rq = get_request(q, rw, NULL, gfp_mask);
+ rq = get_request(q, rw, NULL, gfp_mask);
if (!rq)
spin_unlock_irq(q->queue_lock);
/* q->queue_lock is unlocked at this point */
BUG_ON(!list_empty(&req->queuelist));
BUG_ON(!hlist_unhashed(&req->hash));
- blk_free_request(q, req);
- freed_request(q, flags);
+ blk_free_request(&q->rq, req);
+ freed_request(&q->rq, flags);
}
}
EXPORT_SYMBOL_GPL(__blk_put_request);
* Grab a free request. This is might sleep but can not fail.
* Returns with the queue unlocked.
*/
- req = get_request_wait(q, rw_flags, bio);
+ req = get_request(q, rw_flags, bio, GFP_NOIO);
if (unlikely(!req)) {
bio_endio(bio, -ENODEV); /* @q is dead */
goto out_unlock;
goto end_io;
}
+ /*
+ * Various block parts want %current->io_context and lazy ioc
+ * allocation ends up trading a lot of pain for a small amount of
+ * memory. Just allocate it upfront. This may fail and block
+ * layer knows how to live with it.
+ */
+ create_io_context(GFP_ATOMIC, q->node);
+
if (blk_throtl_bio(q, bio))
return false; /* throttled, will be resubmitted later */
projects / firefly-linux-kernel-4.4.55.git / blobdiff