[PATCH v2 2/6] blk-mq: Add a flag for reserved requests
From: John Garry <hidden>
Date: 2022-06-21 11:22:24
Also in:
linux-doc, linux-mmc, linux-nvme, linux-rdma, linux-s390, linux-scsi, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Add a flag for reserved requests so that drivers may know this for any special handling. Signed-off-by: John Garry <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> --- block/blk-mq.c | 6 ++++++ include/linux/blk-mq.h | 6 ++++++ 2 files changed, 12 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5aa95964191b..d38c97fe89f5 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -474,6 +474,9 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) if (!(data->rq_flags & RQF_ELV)) blk_mq_tag_busy(data->hctx); + if (data->flags & BLK_MQ_REQ_RESERVED) + data->rq_flags |= RQF_RESV; + /* * Try batched alloc if we want more than 1 tag. */
@@ -588,6 +591,9 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, else data.rq_flags |= RQF_ELV; + if (flags & BLK_MQ_REQ_RESERVED) + data.rq_flags |= RQF_RESV; + ret = -EWOULDBLOCK; tag = blk_mq_get_tag(&data); if (tag == BLK_MQ_NO_TAG)
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e2d9daf7e8dd..6d81fe10e850 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -57,6 +57,7 @@ typedef __u32 __bitwise req_flags_t; #define RQF_TIMED_OUT ((__force req_flags_t)(1 << 21)) /* queue has elevator attached */ #define RQF_ELV ((__force req_flags_t)(1 << 22)) +#define RQF_RESV ((__force req_flags_t)(1 << 23)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \
@@ -823,6 +824,11 @@ static inline bool blk_mq_need_time_stamp(struct request *rq) return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_ELV)); } +static inline bool blk_mq_is_reserved_rq(struct request *rq) +{ + return rq->rq_flags & RQF_RESV; +} + /* * Batched completions only work when there is no I/O error and no special * ->end_io handler.
--
2.25.1