[PATCH 7/7] block: add a poll_fn callback to struct request_queue
Christoph Hellwig
hch at lst.de
Thu Nov 2 11:29:54 PDT 2017
That we we can also poll non blk-mq queues. Mostly needed for
the NVMe multipath code, but could also be useful elsewhere.
Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Hannes Reinecke <hare at suse.com>
---
block/blk-core.c | 11 +++++++++++
block/blk-mq.c | 14 +++++---------
drivers/nvme/target/io-cmd.c | 2 +-
fs/block_dev.c | 4 ++--
fs/direct-io.c | 2 +-
fs/iomap.c | 2 +-
include/linux/blkdev.h | 4 +++-
mm/page_io.c | 2 +-
8 files changed, 25 insertions(+), 16 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 54fe673fb3ba..1cab621a552a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2319,6 +2319,17 @@ blk_qc_t submit_bio(struct bio *bio)
}
EXPORT_SYMBOL(submit_bio);
+bool blk_poll(struct request_queue *q, blk_qc_t cookie)
+{
+ if (!q->poll_fn || !blk_qc_t_valid(cookie))
+ return false;
+
+ if (current->plug)
+ blk_flush_plug_list(current->plug, false);
+ return q->poll_fn(q, cookie);
+}
+EXPORT_SYMBOL_GPL(blk_poll);
+
/**
* blk_cloned_rq_check_limits - Helper function to check a cloned request
* for new the queue limits
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7f01d69879d6..10c99cf6fd71 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -37,6 +37,7 @@
#include "blk-wbt.h"
#include "blk-mq-sched.h"
+static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);
static void blk_mq_poll_stats_start(struct request_queue *q);
static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
@@ -2401,6 +2402,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
spin_lock_init(&q->requeue_lock);
blk_queue_make_request(q, blk_mq_make_request);
+ if (q->mq_ops->poll)
+ q->poll_fn = blk_mq_poll;
/*
* Do this after blk_queue_make_request() overrides it...
@@ -2860,20 +2863,14 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
return false;
}
-bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
+static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
{
struct blk_mq_hw_ctx *hctx;
- struct blk_plug *plug;
struct request *rq;
- if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) ||
- !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
+ if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
return false;
- plug = current->plug;
- if (plug)
- blk_flush_plug_list(plug, false);
-
hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
if (!blk_qc_t_is_internal(cookie))
rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
@@ -2891,7 +2888,6 @@ bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
return __blk_mq_poll(hctx, rq);
}
-EXPORT_SYMBOL_GPL(blk_mq_poll);
static int __init blk_mq_init(void)
{
diff --git a/drivers/nvme/target/io-cmd.c b/drivers/nvme/target/io-cmd.c
index 0d4c23dc4532..db632818777d 100644
--- a/drivers/nvme/target/io-cmd.c
+++ b/drivers/nvme/target/io-cmd.c
@@ -94,7 +94,7 @@ static void nvmet_execute_rw(struct nvmet_req *req)
cookie = submit_bio(bio);
- blk_mq_poll(bdev_get_queue(req->ns->bdev), cookie);
+ blk_poll(bdev_get_queue(req->ns->bdev), cookie);
}
static void nvmet_execute_flush(struct nvmet_req *req)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 93d088ffc05c..49a55246ba50 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -249,7 +249,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
if (!READ_ONCE(bio.bi_private))
break;
if (!(iocb->ki_flags & IOCB_HIPRI) ||
- !blk_mq_poll(bdev_get_queue(bdev), qc))
+ !blk_poll(bdev_get_queue(bdev), qc))
io_schedule();
}
__set_current_state(TASK_RUNNING);
@@ -414,7 +414,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
break;
if (!(iocb->ki_flags & IOCB_HIPRI) ||
- !blk_mq_poll(bdev_get_queue(bdev), qc))
+ !blk_poll(bdev_get_queue(bdev), qc))
io_schedule();
}
__set_current_state(TASK_RUNNING);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 62cf812ed0e5..d2bc339cb1e9 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -486,7 +486,7 @@ static struct bio *dio_await_one(struct dio *dio)
dio->waiter = current;
spin_unlock_irqrestore(&dio->bio_lock, flags);
if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
- !blk_mq_poll(dio->bio_disk->queue, dio->bio_cookie))
+ !blk_poll(dio->bio_disk->queue, dio->bio_cookie))
io_schedule();
/* wake up sets us TASK_RUNNING */
spin_lock_irqsave(&dio->bio_lock, flags);
diff --git a/fs/iomap.c b/fs/iomap.c
index 8194d30bdca0..4241bac905b1 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1049,7 +1049,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (!(iocb->ki_flags & IOCB_HIPRI) ||
!dio->submit.last_queue ||
- !blk_mq_poll(dio->submit.last_queue,
+ !blk_poll(dio->submit.last_queue,
dio->submit.cookie))
io_schedule();
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 45c63764a14e..a18ea9b9b8f7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -266,6 +266,7 @@ struct blk_queue_ctx;
typedef void (request_fn_proc) (struct request_queue *q);
typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
+typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t);
typedef int (prep_rq_fn) (struct request_queue *, struct request *);
typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
@@ -408,6 +409,7 @@ struct request_queue {
request_fn_proc *request_fn;
make_request_fn *make_request_fn;
+ poll_q_fn *poll_fn;
prep_rq_fn *prep_rq_fn;
unprep_rq_fn *unprep_rq_fn;
softirq_done_fn *softirq_done_fn;
@@ -991,7 +993,7 @@ extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
int blk_status_to_errno(blk_status_t status);
blk_status_t errno_to_blk_status(int errno);
-bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);
+bool blk_poll(struct request_queue *q, blk_qc_t cookie);
static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
{
diff --git a/mm/page_io.c b/mm/page_io.c
index 21502d341a67..ff04de630c46 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -407,7 +407,7 @@ int swap_readpage(struct page *page, bool do_poll)
if (!READ_ONCE(bio->bi_private))
break;
- if (!blk_mq_poll(disk->queue, qc))
+ if (!blk_poll(disk->queue, qc))
break;
}
__set_current_state(TASK_RUNNING);
--
2.14.2
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