From: Hannes Reinecke <hare@suse.de>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: Sage Weil <sage@redhat.com>, Daniel Disseldorp <ddiss@suse.com>,
Jens Axboe <axboe@kernel.dk>,
ceph-devel@vger.kernel.org, linux-block@vger.kernel.org,
Hannes Reinecke <hare@suse.de>
Subject: [PATCH 13/15] rbd: schedule image_request after preparation
Date: Fri, 31 Jan 2020 11:37:37 +0100 [thread overview]
Message-ID: <20200131103739.136098-14-hare@suse.de> (raw)
In-Reply-To: <20200131103739.136098-1-hare@suse.de>
Instead of pushing I/O directly to the workqueue we should be
preparing it first, and push it onto the workqueue as the last
step. This allows us to signal some back-pressure to the block
layer in case the queue fills up.
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/block/rbd.c | 52 +++++++++++++++-------------------------------------
1 file changed, 15 insertions(+), 37 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 2566d6bd8230..9829f225c57d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4775,9 +4775,10 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
return ret;
}
-static void rbd_queue_workfn(struct work_struct *work)
+static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
{
- struct request *rq = blk_mq_rq_from_pdu(work);
+ struct request *rq = bd->rq;
struct rbd_device *rbd_dev = rq->q->queuedata;
struct rbd_img_request *img_request;
struct ceph_snap_context *snapc = NULL;
@@ -4802,24 +4803,14 @@ static void rbd_queue_workfn(struct work_struct *work)
break;
default:
dout("%s: non-fs request type %d\n", __func__, req_op(rq));
- result = -EIO;
- goto err;
- }
-
- /* Ignore/skip any zero-length requests */
-
- if (!length) {
- dout("%s: zero-length request\n", __func__);
- result = 0;
- goto err_rq;
+ return BLK_STS_IOERR;
}
if (op_type != OBJ_OP_READ) {
if (rbd_is_ro(rbd_dev)) {
rbd_warn(rbd_dev, "%s on read-only mapping",
obj_op_name(op_type));
- result = -EIO;
- goto err;
+ return BLK_STS_IOERR;
}
rbd_assert(!rbd_is_snap(rbd_dev));
}
@@ -4827,11 +4818,17 @@ static void rbd_queue_workfn(struct work_struct *work)
if (offset && length > U64_MAX - offset + 1) {
rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset,
length);
- result = -EINVAL;
- goto err_rq; /* Shouldn't happen */
+ return BLK_STS_NOSPC; /* Shouldn't happen */
}
blk_mq_start_request(rq);
+ /* Ignore/skip any zero-length requests */
+ if (!length) {
+ dout("%s: zero-length request\n", __func__);
+ result = 0;
+ goto err;
+ }
+
mapping_size = READ_ONCE(rbd_dev->mapping.size);
if (op_type != OBJ_OP_READ) {
@@ -4868,8 +4865,8 @@ static void rbd_queue_workfn(struct work_struct *work)
if (result)
goto err_img_request;
- rbd_img_handle_request(img_request, 0);
- return;
+ rbd_img_schedule(img_request, 0);
+ return BLK_STS_OK;
err_img_request:
rbd_img_request_destroy(img_request);
@@ -4880,15 +4877,6 @@ static void rbd_queue_workfn(struct work_struct *work)
ceph_put_snap_context(snapc);
err:
blk_mq_end_request(rq, errno_to_blk_status(result));
-}
-
-static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
- const struct blk_mq_queue_data *bd)
-{
- struct request *rq = bd->rq;
- struct work_struct *work = blk_mq_rq_to_pdu(rq);
-
- queue_work(rbd_wq, work);
return BLK_STS_OK;
}
@@ -5055,18 +5043,8 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
return ret;
}
-static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
- unsigned int hctx_idx, unsigned int numa_node)
-{
- struct work_struct *work = blk_mq_rq_to_pdu(rq);
-
- INIT_WORK(work, rbd_queue_workfn);
- return 0;
-}
-
static const struct blk_mq_ops rbd_mq_ops = {
.queue_rq = rbd_queue_rq,
- .init_request = rbd_init_request,
};
static int rbd_init_disk(struct rbd_device *rbd_dev)
--
2.16.4
next prev parent reply other threads:[~2020-01-31 10:38 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-31 10:37 [PATCH 00/15] rbd: switch to blk-mq Hannes Reinecke
2020-01-31 10:37 ` [PATCH 01/15] rbd: lock object request list Hannes Reinecke
2020-02-03 16:38 ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 02/15] rbd: use READ_ONCE() when checking the mapping size Hannes Reinecke
2020-02-03 16:50 ` Ilya Dryomov
2020-02-04 7:05 ` Hannes Reinecke
2020-01-31 10:37 ` [PATCH 03/15] rbd: reorder rbd_img_advance() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 04/15] rbd: reorder switch statement in rbd_advance_read() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 05/15] rbd: reorder switch statement in rbd_advance_write() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 06/15] rbd: add 'done' state for rbd_obj_advance_copyup() Hannes Reinecke
2020-01-31 10:37 ` [PATCH 07/15] rbd: use callback for image request completion Hannes Reinecke
2020-02-03 17:13 ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 08/15] rbd: add debugging statements for the state machine Hannes Reinecke
2020-01-31 10:37 ` [PATCH 09/15] rbd: count pending object requests in-line Hannes Reinecke
2020-02-03 17:47 ` Ilya Dryomov
2020-02-04 6:59 ` Hannes Reinecke
2020-01-31 10:37 ` [PATCH 10/15] rbd: kill 'work_result' Hannes Reinecke
2020-01-31 10:37 ` [PATCH 11/15] rbd: drop state_mutex in __rbd_img_handle_request() Hannes Reinecke
2020-02-03 18:01 ` Ilya Dryomov
2020-01-31 10:37 ` [PATCH 12/15] rbd: kill img_request kref Hannes Reinecke
2020-01-31 10:37 ` Hannes Reinecke [this message]
2020-02-03 18:40 ` [PATCH 13/15] rbd: schedule image_request after preparation Ilya Dryomov
2020-01-31 10:37 ` [PATCH 14/15] rbd: embed image request as blk_mq request payload Hannes Reinecke
2020-01-31 10:37 ` [PATCH 15/15] rbd: switch to blk-mq Hannes Reinecke
2020-02-03 8:36 ` Christoph Hellwig
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