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authorJens Axboe <axboe@fb.com>2017-01-13 08:09:05 -0700
committerJens Axboe <axboe@fb.com>2017-01-17 10:03:59 -0700
commit4941115bef2bc891aa00a2f0edeaf06dc982325a (patch)
tree5f69e1404d076096cf0f00eac8859db627c6fcdb /block/blk-mq-tag.c
parent2c3ad667902ef6f4b60ef0a3c6f7d8c2b007769a (diff)
blk-mq-tag: cleanup the normal/reserved tag allocation
This is in preparation for having another tag set available. Cleanup the parameters, and allow passing in of tags for blk_mq_put_tag(). Signed-off-by: Jens Axboe <axboe@fb.com> [hch: even more cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'block/blk-mq-tag.c')
-rw-r--r--block/blk-mq-tag.c94
1 files changed, 36 insertions, 58 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index dcf5ce3ba4bf..ced752716878 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -90,32 +90,46 @@ 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_hw_ctx *hctx, struct sbitmap_queue *bt)
{
if (!hctx_may_queue(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;
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->hctx, 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);
do {
prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
- tag = __bt_get(hctx, bt);
+ tag = __blk_mq_get_tag(data->hctx, bt);
if (tag != -1)
break;
@@ -125,14 +139,14 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt,
* some to complete. Note that hctx can be NULL here for
* reserved tag allocation.
*/
- if (hctx)
- blk_mq_run_hw_queue(hctx, false);
+ if (data->hctx)
+ 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->hctx, bt);
if (tag != -1)
break;
@@ -142,61 +156,25 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt,
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;
-
- return tag;
+found_tag:
+ return tag + tag_offset;
}
-unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
+void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
+ struct blk_mq_ctx *ctx, unsigned int tag)
{
- if (data->flags & BLK_MQ_REQ_RESERVED)
- return __blk_mq_get_reserved_tag(data);
- return __blk_mq_get_tag(data);
-}
-
-void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, 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;