block: introduce blk_mq_tagset_iter

Iterator helper to apply a function on all the
tags in a given tagset. export it as it will be used
outside the block layer later on.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 6714507..bce1c76 100644 (file)
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -298,12 +298,12 @@ 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 (reinit_request)(void *, struct request *))
+int blk_mq_tagset_iter(struct blk_mq_tag_set *set, void *data,
+                        int (fn)(void *, struct request *))
 {
        int i, j, ret = 0;
 
-       if (WARN_ON_ONCE(!reinit_request))
+       if (WARN_ON_ONCE(!fn))
                goto out;
 
        for (i = 0; i < set->nr_hw_queues; i++) {
@@ -316,8 +316,7 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set,
                        if (!tags->static_rqs[j])
                                continue;
 
-                       ret = reinit_request(set->driver_data,
-                                            tags->static_rqs[j]);
+                       ret = fn(data, tags->static_rqs[j]);
                        if (ret)
                                goto out;
                }
@@ -326,6 +325,13 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set,
 out:
        return ret;
 }
+EXPORT_SYMBOL_GPL(blk_mq_tagset_iter);
+
+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set,
+                        int (reinit_request)(void *, struct request *))
+{
+       return blk_mq_tagset_iter(set, set->driver_data, reinit_request);
+}
 EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset);
 
 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 50c6485..6bc29f7 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -259,6 +259,8 @@ void blk_freeze_queue_start(struct request_queue *q);
 void blk_mq_freeze_queue_wait(struct request_queue *q);
 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
                                     unsigned long timeout);
+int blk_mq_tagset_iter(struct blk_mq_tag_set *set, void *data,
+               int (reinit_request)(void *, struct request *));
 int blk_mq_reinit_tagset(struct blk_mq_tag_set *set,
                         int (reinit_request)(void *, struct request *));