[PATCH 1/5] blk-mq: Introduce blk_mq_reinit_tagset

Christoph Hellwig
2016-06-06T21:23:50Z

From: Sagi Grimberg <sagi@grimberg.me>

The new nvme-rdma driver will need to reinitialize all the tags as part of
the error recovery procedure (realloc the tag memory region). Add a helper
in blk-mq for it that can iterate over all requests in a tagset to make
this easier.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Stephen Bates <Stephen.Bates@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-mq-tag.c | 26 ++++++++++++++++++++++++++
include/linux/blk-mq.h | 3 +++
2 files changed, 29 insertions(+)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 56a0c37..729bac3 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -485,6 +485,32 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
}
EXPORT_SYMBOL(blk_mq_tagset_busy_iter);

+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set)
+{
+ int i, j, ret = 0;
+
+ if (!set->ops->reinit_request)
+ goto out;
+
+ for (i = 0; i < set->nr_hw_queues; i++) {
+ struct blk_mq_tags *tags = set->tags[i];
+
+ for (j = 0; j < tags->nr_tags; j++) {
+ if (!tags->rqs[j])
+ continue;
+
+ ret = set->ops->reinit_request(set->driver_data,
+ tags->rqs[j]);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset);
+
void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
void *priv)
{
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 6bf8735..9a5d581 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -96,6 +96,7 @@ typedef int (init_request_fn)(void *, struct request *, unsigned int,
unsigned int, unsigned int);
typedef void (exit_request_fn)(void *, struct request *, unsigned int,
unsigned int);
+typedef int (reinit_request_fn)(void *, struct request *);

typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
bool);
@@ -145,6 +146,7 @@ struct blk_mq_ops {
*/
init_request_fn *init_request;
exit_request_fn *exit_request;
+ reinit_request_fn *reinit_request;
};

enum {
@@ -245,6 +247,7 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_unfreeze_queue(struct request_queue *q);
void blk_mq_freeze_queue_start(struct request_queue *q);
+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);

void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);

--
2.1.4