[PATCH 14/17] aoe: convert aoeblk to blk-mq

Jens Axboe
2018-10-11T16:59:06Z

Straight forward conversion - instead of rewriting the internal buffer
retrieval logic, just replace the previous elevator peeking with an
internal list of requests.

Cc: "Ed L. Cashin" <ed.cashin@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/block/aoe/aoe.h | 4 ++++
drivers/block/aoe/aoeblk.c | 49 ++++++++++++++++++++++++++++----------
drivers/block/aoe/aoecmd.c | 17 +++++++++----
drivers/block/aoe/aoedev.c | 14 ++++++-----
4 files changed, 60 insertions(+), 24 deletions(-)

diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index c0ebda1283cc..9b9db29fe712 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -1,4 +1,6 @@
/* Copyright (c) 2013 Coraid, Inc. See COPYING for GPL terms. */
+#include <linux/blk-mq.h>
+
#define VERSION "85"
#define AOE_MAJOR 152
#define DEVICE_NAME "aoe"
@@ -164,6 +166,8 @@ struct aoedev {
struct gendisk *gd;
struct dentry *debugfs;
struct request_queue *blkq;
+ struct list_head rq_list;
+ struct blk_mq_tag_set tag_set;
struct hd_geometry geo;
sector_t ssize;
struct timer_list timer;
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 429ebb84b592..ba4afa0ce1c7 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -6,7 +6,7 @@

#include <linux/kernel.h>
#include <linux/hdreg.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
@@ -274,23 +274,25 @@ aoeblk_release(struct gendisk *disk, fmode_t mode)
spin_unlock_irqrestore(&d->lock, flags);
}

-static void
-aoeblk_request(struct request_queue *q)
+static blk_status_t aoeblk_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
{
- struct aoedev *d;
- struct request *rq;
+ struct aoedev *d = hctx->queue->queuedata;
+
+ spin_lock_irq(&d->lock);

- d = q->queuedata;
if ((d->flags & DEVFL_UP) == 0) {
pr_info_ratelimited("aoe: device %ld.%d is not up\n",
d->aoemajor, d->aoeminor);
- while ((rq = blk_peek_request(q))) {
- blk_start_request(rq);
- aoe_end_request(d, rq, 1);
- }
- return;
+ spin_unlock_irq(&d->lock);
+ blk_mq_start_request(bd->rq);
+ return BLK_STS_IOERR;
}
+
+ list_add_tail(&bd->rq->queuelist, &d->rq_list);
aoecmd_work(d);
+ spin_unlock_irq(&d->lock);
+ return BLK_STS_OK;
}

static int
@@ -345,6 +347,10 @@ static const struct block_device_operations aoe_bdops = {
.owner = THIS_MODULE,
};

+static const struct blk_mq_ops aoeblk_mq_ops = {
+ .queue_rq = aoeblk_queue_rq,
+};
+
/* alloc_disk and add_disk can sleep */
void
aoeblk_gdalloc(void *vp)
@@ -353,9 +359,11 @@ aoeblk_gdalloc(void *vp)
struct gendisk *gd;
mempool_t *mp;
struct request_queue *q;
+ struct blk_mq_tag_set *set;
enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, };
ulong flags;
int late = 0;
+ int err;

spin_lock_irqsave(&d->lock, flags);
if (d->flags & DEVFL_GDALLOC
@@ -382,10 +390,25 @@ aoeblk_gdalloc(void *vp)
d->aoemajor, d->aoeminor);
goto err_disk;
}
- q = blk_init_queue(aoeblk_request, &d->lock);
- if (q == NULL) {
+
+ set = &d->tag_set;
+ set->ops = &aoeblk_mq_ops;
+ set->nr_hw_queues = 1;
+ set->queue_depth = 128;
+ set->numa_node = NUMA_NO_NODE;
+ set->flags = BLK_MQ_F_SHOULD_MERGE;
+ err = blk_mq_alloc_tag_set(set);
+ if (err) {
+ pr_err("aoe: cannot allocate tag set for %ld.%d\n",
+ d->aoemajor, d->aoeminor);
+ goto err_mempool;
+ }
+
+ q = blk_mq_init_queue(set);
+ if (IS_ERR(q)) {
pr_err("aoe: cannot allocate block queue for %ld.%d\n",
d->aoemajor, d->aoeminor);
+ blk_mq_free_tag_set(set);
goto err_mempool;
}

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 136dc507d020..fce0fc1fa7bf 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -7,7 +7,7 @@
#include <linux/ata.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/genhd.h>
@@ -857,10 +857,12 @@ nextbuf(struct aoedev *d)
return d->ip.buf;
rq = d->ip.rq;
if (rq == NULL) {
- rq = blk_peek_request(q);
+ rq = list_first_entry_or_null(&d->rq_list, struct request,
+ queuelist);
if (rq == NULL)
return NULL;
- blk_start_request(rq);
+ list_del_init(&rq->queuelist);
+ blk_mq_start_request(rq);
d->ip.rq = rq;
d->ip.nxbio = rq->bio;
rq->special = (void *) rqbiocnt(rq);
@@ -1045,6 +1047,7 @@ aoe_end_request(struct aoedev *d, struct request *rq, int fastfail)
struct bio *bio;
int bok;
struct request_queue *q;
+ blk_status_t err = BLK_STS_OK;

q = d->blkq;
if (rq == d->ip.rq)
@@ -1052,11 +1055,15 @@ aoe_end_request(struct aoedev *d, struct request *rq, int fastfail)
do {
bio = rq->bio;
bok = !fastfail && !bio->bi_status;
- } while (__blk_end_request(rq, bok ? BLK_STS_OK : BLK_STS_IOERR, bio->bi_iter.bi_size));
+ if (!bok)
+ err = BLK_STS_IOERR;
+ } while (blk_update_request(rq, bok ? BLK_STS_OK : BLK_STS_IOERR, bio->bi_iter.bi_size));
+
+ __blk_mq_end_request(rq, err);

/* cf. http://lkml.org/lkml/2006/10/31/28 */
if (!fastfail)
- __blk_run_queue(q);
+ blk_mq_run_hw_queues(q, true);
}

static void
diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index 41060e9cedf2..96b420ddff3f 100644
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -5,7 +5,7 @@
*/

#include <linux/hdreg.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/slab.h>
@@ -197,7 +197,6 @@ aoedev_downdev(struct aoedev *d)
{
struct aoetgt *t, **tt, **te;
struct list_head *head, *pos, *nx;
- struct request *rq;
int i;

d->flags &= ~DEVFL_UP;
@@ -225,10 +224,11 @@ aoedev_downdev(struct aoedev *d)

/* fast fail all pending I/O */
if (d->blkq) {
- while ((rq = blk_peek_request(d->blkq))) {
- blk_start_request(rq);
- aoe_end_request(d, rq, 1);
- }
+ /* UP is cleared, freeze+quiesce to insure all are errored */
+ blk_mq_freeze_queue(d->blkq);
+ blk_mq_quiesce_queue(d->blkq);
+ blk_mq_unquiesce_queue(d->blkq);
+ blk_mq_unfreeze_queue(d->blkq);
}

if (d->gd)
@@ -278,6 +278,7 @@ freedev(struct aoedev *d)
aoedisk_rm_sysfs(d);
del_gendisk(d->gd);
put_disk(d->gd);
+ blk_mq_free_tag_set(&d->tag_set);
blk_cleanup_queue(d->blkq);
}
t = d->targets;
@@ -464,6 +465,7 @@ aoedev_by_aoeaddr(ulong maj, int min, int do_alloc)
d->ntargets = NTARGETS;
INIT_WORK(&d->work, aoecmd_sleepwork);
spin_lock_init(&d->lock);
+ INIT_LIST_HEAD(&d->rq_list);
skb_queue_head_init(&d->skbpool);
timer_setup(&d->timer, dummy_timer, 0);
d->timer.expires = jiffies + HZ;
--
2.17.1