#include <linux/cache.h>
#include <linux/sched/sysctl.h>
#include <linux/delay.h>
+#include <linux/crash_dump.h>
#include <trace/events/block.h>
if (tag != BLK_MQ_TAG_FAIL) {
rq = data->hctx->tags->rqs[tag];
- rq->cmd_flags = 0;
if (blk_mq_tag_busy(data->hctx)) {
rq->cmd_flags = REQ_MQ_INFLIGHT;
atomic_inc(&data->hctx->nr_active);
struct blk_mq_hw_ctx *hctx;
struct request *rq;
struct blk_mq_alloc_data alloc_data;
+ int ret;
- if (blk_mq_queue_enter(q))
- return NULL;
+ ret = blk_mq_queue_enter(q);
+ if (ret)
+ return ERR_PTR(ret);
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
ctx = alloc_data.ctx;
}
blk_mq_put_ctx(ctx);
+ if (!rq)
+ return ERR_PTR(-EWOULDBLOCK);
return rq;
}
EXPORT_SYMBOL(blk_mq_alloc_request);
if (rq->cmd_flags & REQ_MQ_INFLIGHT)
atomic_dec(&hctx->nr_active);
+ rq->cmd_flags = 0;
clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
blk_mq_put_tag(hctx, tag, &ctx->last_tag);
hctx->cmd_size);
}
-inline void __blk_mq_end_io(struct request *rq, int error)
+inline void __blk_mq_end_request(struct request *rq, int error)
{
blk_account_io_done(rq);
blk_mq_free_request(rq);
}
}
-EXPORT_SYMBOL(__blk_mq_end_io);
+EXPORT_SYMBOL(__blk_mq_end_request);
-void blk_mq_end_io(struct request *rq, int error)
+void blk_mq_end_request(struct request *rq, int error)
{
if (blk_update_request(rq, error, blk_rq_bytes(rq)))
BUG();
- __blk_mq_end_io(rq, error);
+ __blk_mq_end_request(rq, error);
}
-EXPORT_SYMBOL(blk_mq_end_io);
+EXPORT_SYMBOL(blk_mq_end_request);
static void __blk_mq_complete_request_remote(void *data)
{
struct request_queue *q = rq->q;
if (!q->softirq_done_fn)
- blk_mq_end_io(rq, rq->errors);
+ blk_mq_end_request(rq, rq->errors);
else
blk_mq_ipi_complete_request(rq);
}
}
EXPORT_SYMBOL(blk_mq_complete_request);
-static void blk_mq_start_request(struct request *rq, bool last)
+void blk_mq_start_request(struct request *rq)
{
struct request_queue *q = rq->q;
blk_add_timer(rq);
+ /*
+ * Ensure that ->deadline is visible before set the started
+ * flag and clear the completed flag.
+ */
+ smp_mb__before_atomic();
+
/*
* Mark us as started and clear complete. Complete might have been
* set if requeue raced with timeout, which then marked it as
*/
rq->nr_phys_segments++;
}
-
- /*
- * Flag the last request in the series so that drivers know when IO
- * should be kicked off, if they don't do it on a per-request basis.
- *
- * Note: the flag isn't the only condition drivers should do kick off.
- * If drive is busy, the last request might not have the bit set.
- */
- if (last)
- rq->cmd_flags |= REQ_END;
}
+EXPORT_SYMBOL(blk_mq_start_request);
static void __blk_mq_requeue_request(struct request *rq)
{
struct request_queue *q = rq->q;
trace_block_rq_requeue(q, rq);
- clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
- rq->cmd_flags &= ~REQ_END;
-
- if (q->dma_drain_size && blk_rq_bytes(rq))
- rq->nr_phys_segments--;
+ if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
+ if (q->dma_drain_size && blk_rq_bytes(rq))
+ rq->nr_phys_segments--;
+ }
}
void blk_mq_requeue_request(struct request *rq)
{
__blk_mq_requeue_request(rq);
- blk_clear_rq_complete(rq);
BUG_ON(blk_queued_rq(rq));
blk_mq_add_to_requeue_list(rq, true);
blk_mq_insert_request(rq, false, false, false);
}
- blk_mq_run_queues(q, false);
+ /*
+ * Use the start variant of queue running here, so that running
+ * the requeue work will kick stopped queues.
+ */
+ blk_mq_start_hw_queues(q);
}
void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
EXPORT_SYMBOL(blk_mq_tag_to_rq);
struct blk_mq_timeout_data {
- struct blk_mq_hw_ctx *hctx;
- unsigned long *next;
- unsigned int *next_set;
+ unsigned long next;
+ unsigned int next_set;
};
-static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
-{
- struct blk_mq_timeout_data *data = __data;
- struct blk_mq_hw_ctx *hctx = data->hctx;
- unsigned int tag;
-
- /* It may not be in flight yet (this is where
- * the REQ_ATOMIC_STARTED flag comes in). The requests are
- * statically allocated, so we know it's always safe to access the
- * memory associated with a bit offset into ->rqs[].
- */
- tag = 0;
- do {
- struct request *rq;
-
- tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag);
- if (tag >= hctx->tags->nr_tags)
- break;
-
- rq = blk_mq_tag_to_rq(hctx->tags, tag++);
- if (rq->q != hctx->queue)
- continue;
- if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
- continue;
-
- blk_rq_check_expired(rq, data->next, data->next_set);
- } while (1);
-}
-
-static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx,
- unsigned long *next,
- unsigned int *next_set)
+void blk_mq_rq_timed_out(struct request *req, bool reserved)
{
- struct blk_mq_timeout_data data = {
- .hctx = hctx,
- .next = next,
- .next_set = next_set,
- };
-
- /*
- * Ask the tagging code to iterate busy requests, so we can
- * check them for timeout.
- */
- blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data);
-}
-
-static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq)
-{
- struct request_queue *q = rq->q;
+ struct blk_mq_ops *ops = req->q->mq_ops;
+ enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
/*
* We know that complete is set at this point. If STARTED isn't set
* we both flags will get cleared. So check here again, and ignore
* a timeout event with a request that isn't active.
*/
- if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
- return BLK_EH_NOT_HANDLED;
+ if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
+ return;
- if (!q->mq_ops->timeout)
- return BLK_EH_RESET_TIMER;
+ if (ops->timeout)
+ ret = ops->timeout(req, reserved);
+
+ switch (ret) {
+ case BLK_EH_HANDLED:
+ __blk_mq_complete_request(req);
+ break;
+ case BLK_EH_RESET_TIMER:
+ blk_add_timer(req);
+ blk_clear_rq_complete(req);
+ break;
+ case BLK_EH_NOT_HANDLED:
+ break;
+ default:
+ printk(KERN_ERR "block: bad eh return: %d\n", ret);
+ break;
+ }
+}
+
+static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, void *priv, bool reserved)
+{
+ struct blk_mq_timeout_data *data = priv;
+
+ if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+ return;
- return q->mq_ops->timeout(rq);
+ if (time_after_eq(jiffies, rq->deadline)) {
+ if (!blk_mark_rq_complete(rq))
+ blk_mq_rq_timed_out(rq, reserved);
+ } else if (!data->next_set || time_after(data->next, rq->deadline)) {
+ data->next = rq->deadline;
+ data->next_set = 1;
+ }
}
-static void blk_mq_rq_timer(unsigned long data)
+static void blk_mq_rq_timer(unsigned long priv)
{
- struct request_queue *q = (struct request_queue *) data;
+ struct request_queue *q = (struct request_queue *)priv;
+ struct blk_mq_timeout_data data = {
+ .next = 0,
+ .next_set = 0,
+ };
struct blk_mq_hw_ctx *hctx;
- unsigned long next = 0;
- int i, next_set = 0;
+ int i;
queue_for_each_hw_ctx(q, hctx, i) {
/*
if (!hctx->nr_ctx || !hctx->tags)
continue;
- blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set);
+ blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data);
}
- if (next_set) {
- next = blk_rq_timeout(round_jiffies_up(next));
- mod_timer(&q->timeout, next);
+ if (data.next_set) {
+ data.next = blk_rq_timeout(round_jiffies_up(data.next));
+ mod_timer(&q->timeout, data.next);
} else {
queue_for_each_hw_ctx(q, hctx, i)
blk_mq_tag_idle(hctx);
rq = list_first_entry(&rq_list, struct request, queuelist);
list_del_init(&rq->queuelist);
- blk_mq_start_request(rq, list_empty(&rq_list));
-
- ret = q->mq_ops->queue_rq(hctx, rq);
+ ret = q->mq_ops->queue_rq(hctx, rq, list_empty(&rq_list));
switch (ret) {
case BLK_MQ_RQ_QUEUE_OK:
queued++;
pr_err("blk-mq: bad return on queue: %d\n", ret);
case BLK_MQ_RQ_QUEUE_ERROR:
rq->errors = -EIO;
- blk_mq_end_io(rq, rq->errors);
+ blk_mq_end_request(rq, rq->errors);
break;
}
hctx = q->mq_ops->map_queue(q, ctx->cpu);
- if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) &&
- !(rq->cmd_flags & (REQ_FLUSH_SEQ))) {
- blk_insert_flush(rq);
- } else {
- spin_lock(&ctx->lock);
- __blk_mq_insert_request(hctx, rq, at_head);
- spin_unlock(&ctx->lock);
- }
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, at_head);
+ spin_unlock(&ctx->lock);
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
int ret;
blk_mq_bio_to_request(rq, bio);
- blk_mq_start_request(rq, true);
/*
* 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(data.hctx, rq);
+ ret = q->mq_ops->queue_rq(data.hctx, rq, true);
if (ret == BLK_MQ_RQ_QUEUE_OK)
goto done;
else {
if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
rq->errors = -EIO;
- blk_mq_end_io(rq, rq->errors);
+ blk_mq_end_request(rq, rq->errors);
goto done;
}
}
continue;
set->ops->exit_request(set->driver_data, tags->rqs[i],
hctx_idx, i);
+ tags->rqs[i] = NULL;
}
}
INIT_LIST_HEAD(&tags->page_list);
- tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *),
- GFP_KERNEL, set->numa_node);
+ tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *),
+ GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
+ set->numa_node);
if (!tags->rqs) {
blk_mq_free_tags(tags);
return NULL;
this_order--;
do {
- page = alloc_pages_node(set->numa_node, GFP_KERNEL,
- this_order);
+ page = alloc_pages_node(set->numa_node,
+ GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
+ this_order);
if (page)
break;
if (!this_order--)
left -= to_do * rq_size;
for (j = 0; j < to_do; j++) {
tags->rqs[i] = p;
+ tags->rqs[i]->atomic_flags = 0;
+ tags->rqs[i]->cmd_flags = 0;
if (set->ops->init_request) {
if (set->ops->init_request(set->driver_data,
tags->rqs[i], hctx_idx, i,
- set->numa_node))
+ set->numa_node)) {
+ tags->rqs[i] = NULL;
goto fail;
+ }
}
p += rq_size;
return tags;
fail:
- pr_warn("%s: failed to allocate requests\n", __func__);
blk_mq_free_rq_map(set, tags, hctx_idx);
return NULL;
}
return NOTIFY_OK;
}
+static void blk_mq_exit_hctx(struct request_queue *q,
+ struct blk_mq_tag_set *set,
+ struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+ blk_mq_tag_idle(hctx);
+
+ if (set->ops->exit_hctx)
+ set->ops->exit_hctx(hctx, hctx_idx);
+
+ blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+ kfree(hctx->ctxs);
+ blk_mq_free_bitmap(&hctx->ctx_map);
+}
+
static void blk_mq_exit_hw_queues(struct request_queue *q,
struct blk_mq_tag_set *set, int nr_queue)
{
queue_for_each_hw_ctx(q, hctx, i) {
if (i == nr_queue)
break;
-
- blk_mq_tag_idle(hctx);
-
- if (set->ops->exit_hctx)
- set->ops->exit_hctx(hctx, i);
-
- blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
- kfree(hctx->ctxs);
- blk_mq_free_bitmap(&hctx->ctx_map);
+ blk_mq_exit_hctx(q, set, hctx, i);
}
-
}
static void blk_mq_free_hw_queues(struct request_queue *q,
}
}
-static int blk_mq_init_hw_queues(struct request_queue *q,
- struct blk_mq_tag_set *set)
+static int blk_mq_init_hctx(struct request_queue *q,
+ struct blk_mq_tag_set *set,
+ struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
{
- struct blk_mq_hw_ctx *hctx;
- unsigned int i;
+ int node;
+
+ node = hctx->numa_node;
+ if (node == NUMA_NO_NODE)
+ node = hctx->numa_node = set->numa_node;
+
+ INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
+ INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
+ spin_lock_init(&hctx->lock);
+ INIT_LIST_HEAD(&hctx->dispatch);
+ hctx->queue = q;
+ hctx->queue_num = hctx_idx;
+ hctx->flags = set->flags;
+ hctx->cmd_size = set->cmd_size;
+
+ blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
+ blk_mq_hctx_notify, hctx);
+ blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
+
+ hctx->tags = set->tags[hctx_idx];
/*
- * Initialize hardware queues
+ * Allocate space for all possible cpus to avoid allocation at
+ * runtime
*/
- queue_for_each_hw_ctx(q, hctx, i) {
- int node;
+ hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
+ GFP_KERNEL, node);
+ if (!hctx->ctxs)
+ goto unregister_cpu_notifier;
- node = hctx->numa_node;
- if (node == NUMA_NO_NODE)
- node = hctx->numa_node = set->numa_node;
+ if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
+ goto free_ctxs;
- INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
- INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
- spin_lock_init(&hctx->lock);
- INIT_LIST_HEAD(&hctx->dispatch);
- hctx->queue = q;
- hctx->queue_num = i;
- hctx->flags = set->flags;
- hctx->cmd_size = set->cmd_size;
+ hctx->nr_ctx = 0;
- blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
- blk_mq_hctx_notify, hctx);
- blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
+ if (set->ops->init_hctx &&
+ set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
+ goto free_bitmap;
- hctx->tags = set->tags[i];
+ return 0;
- /*
- * Allocate space for all possible cpus to avoid allocation at
- * runtime
- */
- hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
- GFP_KERNEL, node);
- if (!hctx->ctxs)
- break;
+ free_bitmap:
+ blk_mq_free_bitmap(&hctx->ctx_map);
+ free_ctxs:
+ kfree(hctx->ctxs);
+ unregister_cpu_notifier:
+ blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
- if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
- break;
+ return -1;
+}
- hctx->nr_ctx = 0;
+static int blk_mq_init_hw_queues(struct request_queue *q,
+ struct blk_mq_tag_set *set)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
- if (set->ops->init_hctx &&
- set->ops->init_hctx(hctx, set->driver_data, i))
+ /*
+ * Initialize hardware queues
+ */
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (blk_mq_init_hctx(q, set, hctx, i))
break;
}
if (!ctx)
return ERR_PTR(-ENOMEM);
+ /*
+ * If a crashdump is active, then we are potentially in a very
+ * memory constrained environment. Limit us to 1 queue and
+ * 64 tags to prevent using too much memory.
+ */
+ if (is_kdump_kernel()) {
+ set->nr_hw_queues = 1;
+ set->queue_depth = min(64U, set->queue_depth);
+ }
+
hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
set->numa_node);
else
blk_queue_make_request(q, blk_sq_make_request);
- blk_queue_rq_timed_out(q, blk_mq_rq_timed_out);
if (set->timeout)
blk_queue_rq_timeout(q, set->timeout);
if (set->ops->complete)
blk_queue_softirq_done(q, set->ops->complete);
- blk_mq_init_flush(q);
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
- q->flush_rq = kzalloc(round_up(sizeof(struct request) +
- set->cmd_size, cache_line_size()),
- GFP_KERNEL);
- if (!q->flush_rq)
- goto err_hw;
-
if (blk_mq_init_hw_queues(q, set))
- goto err_flush_rq;
+ goto err_hw;
mutex_lock(&all_q_mutex);
list_add_tail(&q->all_q_node, &all_q_list);
blk_mq_add_queue_tag_set(set, q);
+ if (blk_mq_init_flush(q))
+ goto err_hw_queues;
+
blk_mq_map_swqueue(q);
return q;
-err_flush_rq:
- kfree(q->flush_rq);
+err_hw_queues:
+ blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
err_hw:
blk_cleanup_queue(q);
err_hctxs:
return NOTIFY_OK;
}
+static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
+{
+ int i;
+
+ for (i = 0; i < set->nr_hw_queues; i++) {
+ set->tags[i] = blk_mq_init_rq_map(set, i);
+ if (!set->tags[i])
+ goto out_unwind;
+ }
+
+ return 0;
+
+out_unwind:
+ while (--i >= 0)
+ blk_mq_free_rq_map(set, set->tags[i], i);
+
+ return -ENOMEM;
+}
+
+/*
+ * Allocate the request maps associated with this tag_set. Note that this
+ * may reduce the depth asked for, if memory is tight. set->queue_depth
+ * will be updated to reflect the allocated depth.
+ */
+static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
+{
+ unsigned int depth;
+ int err;
+
+ depth = set->queue_depth;
+ do {
+ err = __blk_mq_alloc_rq_maps(set);
+ if (!err)
+ break;
+
+ set->queue_depth >>= 1;
+ if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
+ err = -ENOMEM;
+ break;
+ }
+ } while (set->queue_depth);
+
+ if (!set->queue_depth || err) {
+ pr_err("blk-mq: failed to allocate request map\n");
+ return -ENOMEM;
+ }
+
+ if (depth != set->queue_depth)
+ pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
+ depth, set->queue_depth);
+
+ return 0;
+}
+
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
*/
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
{
- int i;
-
if (!set->nr_hw_queues)
return -EINVAL;
if (!set->queue_depth)
sizeof(struct blk_mq_tags *),
GFP_KERNEL, set->numa_node);
if (!set->tags)
- goto out;
+ return -ENOMEM;
- for (i = 0; i < set->nr_hw_queues; i++) {
- set->tags[i] = blk_mq_init_rq_map(set, i);
- if (!set->tags[i])
- goto out_unwind;
- }
+ if (blk_mq_alloc_rq_maps(set))
+ goto enomem;
mutex_init(&set->tag_list_lock);
INIT_LIST_HEAD(&set->tag_list);
return 0;
-
-out_unwind:
- while (--i >= 0)
- blk_mq_free_rq_map(set, set->tags[i], i);
-out:
+enomem:
+ kfree(set->tags);
+ set->tags = NULL;
return -ENOMEM;
}
EXPORT_SYMBOL(blk_mq_alloc_tag_set);
}
kfree(set->tags);
+ set->tags = NULL;
}
EXPORT_SYMBOL(blk_mq_free_tag_set);
projects / linux-beck.git / blobdiff