Now request is thought as in-flight only when its state is updated as
MQ_RQ_IN_FLIGHT, which is done by driver via blk_mq_start_request().
Actually from blk-mq's view, one rq can be thought as in-flight
after its tag is >= 0.
Add one new function of blk_mq_all_tag_iter so that we can iterate
every in-flight request, and this way is more flexible since caller
can decide to handle request according to rq's state.
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: John Garry <john.garry@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq-tag.c | 33 +++++++++++++++++++++++++++++----
block/blk-mq-tag.h | 2 ++
2 files changed, 31 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 586c9d6e904a..c27c6dfc7d36 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -257,6 +257,7 @@ struct bt_tags_iter_data {
busy_tag_iter_fn *fn;
void *data;
bool reserved;
+ bool iterate_all;
};
static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
@@ -274,7 +275,7 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
* test and set the bit before assining ->rqs[].
*/
rq = tags->rqs[bitnr];
- if (rq && blk_mq_request_started(rq))
+ if (rq && (iter_data->iterate_all || blk_mq_request_started(rq)))
return iter_data->fn(rq, iter_data->data, reserved);
return true;
@@ -294,13 +295,15 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
* bitmap_tags member of struct blk_mq_tags.
*/
static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt,
- busy_tag_iter_fn *fn, void *data, bool reserved)
+ busy_tag_iter_fn *fn, void *data, bool reserved,
+ bool iterate_all)
{
struct bt_tags_iter_data iter_data = {
.tags = tags,
.fn = fn,
.data = data,
.reserved = reserved,
+ .iterate_all = iterate_all,
};
if (tags->rqs)
@@ -321,8 +324,30 @@ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
busy_tag_iter_fn *fn, void *priv)
{
if (tags->nr_reserved_tags)
- bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true);
- bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false);
+ bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true,
+ false);
+ bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false, false);
+}
+
+/**
+ * blk_mq_all_tag_iter - iterate over all requests in a tag map
+ * @tags: Tag map to iterate over.
+ * @fn: Pointer to the function that will be called for each
+ * request. @fn will be called as follows: @fn(rq, @priv,
+ * reserved) where rq is a pointer to a request. 'reserved'
+ * indicates whether or not @rq is a reserved request. Return
+ * true to continue iterating tags, false to stop.
+ * @priv: Will be passed as second argument to @fn.
+ *
+ * It is the caller's responsibility to check rq's state in @fn.
+ */
+void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+ void *priv)
+{
+ if (tags->nr_reserved_tags)
+ bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true,
+ true);
+ bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false, true);
}
/**
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 2b8321efb682..d19546e8246b 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -34,6 +34,8 @@ extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
void *priv);
+void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+ void *priv);
static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
struct blk_mq_hw_ctx *hctx)
--
2.25.2
