[PATCH 2/2] blk-mq: add flag for drivers wanting blocking ->queue_rq()
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STALE3667d
From: Jens Axboe <hidden>
Date: 2016-09-22 14:53:00
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
If a driver sets BLK_MQ_F_BLOCKING, it is allowed to block in its ->queue_rq() handler. For that case, blk-mq ensures that we always calls it from a safe context. Signed-off-by: Jens Axboe <redacted> --- block/blk-mq.c | 2 +- include/linux/blk-mq.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c29700010b5c..eae2f12f011f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -908,7 +908,7 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) !blk_mq_hw_queue_mapped(hctx))) return; - if (!async) { + if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { int cpu = get_cpu(); if (cpumask_test_cpu(cpu, hctx->cpumask)) { __blk_mq_run_hw_queue(hctx);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index fbcfdf323243..5daa0ef756dd 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -155,6 +155,7 @@ enum { BLK_MQ_F_TAG_SHARED = 1 << 1, BLK_MQ_F_SG_MERGE = 1 << 2, BLK_MQ_F_DEFER_ISSUE = 1 << 4, + BLK_MQ_F_BLOCKING = 1 << 5, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, BLK_MQ_F_ALLOC_POLICY_BITS = 1,
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2.7.4