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authorKeith Busch <keith.busch@intel.com>2015-06-01 09:29:53 -0600
committerJens Axboe <axboe@fb.com>2015-06-01 14:35:56 -0600
commitf26cdc8536ad50fb802a0445f836b4f94ca09ae7 (patch)
tree8863e8e297fd10241d7ff1e24cdef4ab0b7c625e /block/blk-mq-tag.c
parente548ca4ee4595f65b262661d166310ad8a149bec (diff)
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blk-mq: Shared tag enhancements
Storage controllers may expose multiple block devices that share hardware resources managed by blk-mq. This patch enhances the shared tags so a low-level driver can access the shared resources not tied to the unshared h/w contexts. This way the LLD can dynamically add and delete disks and request queues without having to track all the request_queue hctx's to iterate outstanding tags. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq-tag.c')
-rw-r--r--block/blk-mq-tag.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index be3290cc0644..9b6e28830b82 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -438,6 +438,39 @@ static void bt_for_each(struct blk_mq_hw_ctx *hctx,
}
}
+static void bt_tags_for_each(struct blk_mq_tags *tags,
+ struct blk_mq_bitmap_tags *bt, unsigned int off,
+ busy_tag_iter_fn *fn, void *data, bool reserved)
+{
+ struct request *rq;
+ int bit, i;
+
+ if (!tags->rqs)
+ return;
+ for (i = 0; i < bt->map_nr; i++) {
+ struct blk_align_bitmap *bm = &bt->map[i];
+
+ for (bit = find_first_bit(&bm->word, bm->depth);
+ bit < bm->depth;
+ bit = find_next_bit(&bm->word, bm->depth, bit + 1)) {
+ rq = blk_mq_tag_to_rq(tags, off + bit);
+ fn(rq, data, reserved);
+ }
+
+ off += (1 << bt->bits_per_word);
+ }
+}
+
+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, 0, fn, priv, true);
+ bt_tags_for_each(tags, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv,
+ false);
+}
+EXPORT_SYMBOL(blk_mq_all_tag_busy_iter);
+
void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
void *priv)
{
@@ -580,6 +613,11 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
if (!tags)
return NULL;
+ if (!zalloc_cpumask_var(&tags->cpumask, GFP_KERNEL)) {
+ kfree(tags);
+ return NULL;
+ }
+
tags->nr_tags = total_tags;
tags->nr_reserved_tags = reserved_tags;