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-rw-r--r--block/blk-mq-tag.c190
1 files changed, 92 insertions, 98 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index dcf5ce3ba4bf..54c84363c1b2 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -90,113 +90,97 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
return atomic_read(&hctx->nr_active) < depth;
}
-static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt)
+static int __blk_mq_get_tag(struct blk_mq_alloc_data *data,
+ struct sbitmap_queue *bt)
{
- if (!hctx_may_queue(hctx, bt))
+ if (!(data->flags & BLK_MQ_REQ_INTERNAL) &&
+ !hctx_may_queue(data->hctx, bt))
return -1;
return __sbitmap_queue_get(bt);
}
-static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt,
- struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags)
+unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
{
+ struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
+ struct sbitmap_queue *bt;
struct sbq_wait_state *ws;
DEFINE_WAIT(wait);
+ unsigned int tag_offset;
+ bool drop_ctx;
int tag;
- tag = __bt_get(hctx, bt);
+ if (data->flags & BLK_MQ_REQ_RESERVED) {
+ if (unlikely(!tags->nr_reserved_tags)) {
+ WARN_ON_ONCE(1);
+ return BLK_MQ_TAG_FAIL;
+ }
+ bt = &tags->breserved_tags;
+ tag_offset = 0;
+ } else {
+ bt = &tags->bitmap_tags;
+ tag_offset = tags->nr_reserved_tags;
+ }
+
+ tag = __blk_mq_get_tag(data, bt);
if (tag != -1)
- return tag;
+ goto found_tag;
if (data->flags & BLK_MQ_REQ_NOWAIT)
- return -1;
+ return BLK_MQ_TAG_FAIL;
- ws = bt_wait_ptr(bt, hctx);
+ ws = bt_wait_ptr(bt, data->hctx);
+ drop_ctx = data->ctx == NULL;
do {
prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
- tag = __bt_get(hctx, bt);
+ tag = __blk_mq_get_tag(data, bt);
if (tag != -1)
break;
/*
* We're out of tags on this hardware queue, kick any
* pending IO submits before going to sleep waiting for
- * some to complete. Note that hctx can be NULL here for
- * reserved tag allocation.
+ * some to complete.
*/
- if (hctx)
- blk_mq_run_hw_queue(hctx, false);
+ blk_mq_run_hw_queue(data->hctx, false);
/*
* Retry tag allocation after running the hardware queue,
* as running the queue may also have found completions.
*/
- tag = __bt_get(hctx, bt);
+ tag = __blk_mq_get_tag(data, bt);
if (tag != -1)
break;
- blk_mq_put_ctx(data->ctx);
+ if (data->ctx)
+ blk_mq_put_ctx(data->ctx);
io_schedule();
data->ctx = blk_mq_get_ctx(data->q);
data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu);
- if (data->flags & BLK_MQ_REQ_RESERVED) {
- bt = &data->hctx->tags->breserved_tags;
- } else {
- hctx = data->hctx;
- bt = &hctx->tags->bitmap_tags;
- }
+ tags = blk_mq_tags_from_data(data);
+ if (data->flags & BLK_MQ_REQ_RESERVED)
+ bt = &tags->breserved_tags;
+ else
+ bt = &tags->bitmap_tags;
+
finish_wait(&ws->wait, &wait);
- ws = bt_wait_ptr(bt, hctx);
+ ws = bt_wait_ptr(bt, data->hctx);
} while (1);
- finish_wait(&ws->wait, &wait);
- return tag;
-}
-
-static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data)
-{
- int tag;
-
- tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx,
- data->hctx->tags);
- if (tag >= 0)
- return tag + data->hctx->tags->nr_reserved_tags;
-
- return BLK_MQ_TAG_FAIL;
-}
-
-static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data)
-{
- int tag;
-
- if (unlikely(!data->hctx->tags->nr_reserved_tags)) {
- WARN_ON_ONCE(1);
- return BLK_MQ_TAG_FAIL;
- }
-
- tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL,
- data->hctx->tags);
- if (tag < 0)
- return BLK_MQ_TAG_FAIL;
+ if (drop_ctx && data->ctx)
+ blk_mq_put_ctx(data->ctx);
- return tag;
-}
+ finish_wait(&ws->wait, &wait);
-unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
-{
- if (data->flags & BLK_MQ_REQ_RESERVED)
- return __blk_mq_get_reserved_tag(data);
- return __blk_mq_get_tag(data);
+found_tag:
+ return tag + tag_offset;
}
-void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
- unsigned int tag)
+void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
+ struct blk_mq_ctx *ctx, unsigned int tag)
{
- struct blk_mq_tags *tags = hctx->tags;
-
if (tag >= tags->nr_reserved_tags) {
const int real_tag = tag - tags->nr_reserved_tags;
@@ -312,11 +296,11 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set)
struct blk_mq_tags *tags = set->tags[i];
for (j = 0; j < tags->nr_tags; j++) {
- if (!tags->rqs[j])
+ if (!tags->static_rqs[j])
continue;
ret = set->ops->reinit_request(set->driver_data,
- tags->rqs[j]);
+ tags->static_rqs[j]);
if (ret)
goto out;
}
@@ -351,11 +335,6 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
}
-static unsigned int bt_unused_tags(const struct sbitmap_queue *bt)
-{
- return bt->sb.depth - sbitmap_weight(&bt->sb);
-}
-
static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
bool round_robin, int node)
{
@@ -411,19 +390,56 @@ void blk_mq_free_tags(struct blk_mq_tags *tags)
kfree(tags);
}
-int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth)
+int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_tags **tagsptr, unsigned int tdepth,
+ bool can_grow)
{
- tdepth -= tags->nr_reserved_tags;
- if (tdepth > tags->nr_tags)
+ struct blk_mq_tags *tags = *tagsptr;
+
+ if (tdepth <= tags->nr_reserved_tags)
return -EINVAL;
+ tdepth -= tags->nr_reserved_tags;
+
/*
- * Don't need (or can't) update reserved tags here, they remain
- * static and should never need resizing.
+ * If we are allowed to grow beyond the original size, allocate
+ * a new set of tags before freeing the old one.
*/
- sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+ if (tdepth > tags->nr_tags) {
+ struct blk_mq_tag_set *set = hctx->queue->tag_set;
+ struct blk_mq_tags *new;
+ bool ret;
+
+ if (!can_grow)
+ return -EINVAL;
+
+ /*
+ * We need some sort of upper limit, set it high enough that
+ * no valid use cases should require more.
+ */
+ if (tdepth > 16 * BLKDEV_MAX_RQ)
+ return -EINVAL;
+
+ new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, 0);
+ if (!new)
+ return -ENOMEM;
+ ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth);
+ if (ret) {
+ blk_mq_free_rq_map(new);
+ return -ENOMEM;
+ }
+
+ blk_mq_free_rqs(set, *tagsptr, hctx->queue_num);
+ blk_mq_free_rq_map(*tagsptr);
+ *tagsptr = new;
+ } else {
+ /*
+ * Don't need (or can't) update reserved tags here, they
+ * remain static and should never need resizing.
+ */
+ sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+ }
- blk_mq_tag_wakeup_all(tags, false);
return 0;
}
@@ -454,25 +470,3 @@ u32 blk_mq_unique_tag(struct request *rq)
(rq->tag & BLK_MQ_UNIQUE_TAG_MASK);
}
EXPORT_SYMBOL(blk_mq_unique_tag);
-
-ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page)
-{
- char *orig_page = page;
- unsigned int free, res;
-
- if (!tags)
- return 0;
-
- page += sprintf(page, "nr_tags=%u, reserved_tags=%u, "
- "bits_per_word=%u\n",
- tags->nr_tags, tags->nr_reserved_tags,
- 1U << tags->bitmap_tags.sb.shift);
-
- free = bt_unused_tags(&tags->bitmap_tags);
- res = bt_unused_tags(&tags->breserved_tags);
-
- page += sprintf(page, "nr_free=%u, nr_reserved=%u\n", free, res);
- page += sprintf(page, "active_queues=%u\n", atomic_read(&tags->active_queues));
-
- return page - orig_page;
-}
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