[PATCH AUTOSEL 4.19 021/237] skd: fixup usage of legacy IO API

[PATCH AUTOSEL 4.19 021/237] skd: fixup usage of legacy IO API

[Sasha Levin]

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit 6d1f9dfde7343c4ebfb8f84dcb333af571bb3b22 ]

We need to be using the mq variant of request requeue here.

Fixes: ca33dd92968b ("skd: Convert to blk-mq")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/block/skd_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index 87b9e7fbf0621..27323fa23997d 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -1416,7 +1416,7 @@ static void skd_resolve_req_exception(struct skd_device *skdev,
 
 	case SKD_CHECK_STATUS_BUSY_IMMINENT:
 		skd_log_skreq(skdev, skreq, "retry(busy)");
-		blk_requeue_request(skdev->queue, req);
+		blk_mq_requeue_request(req, true);
 		dev_info(&skdev->pdev->dev, "drive BUSY imminent\n");
 		skdev->state = SKD_DRVR_STATE_BUSY_IMMINENT;
 		skdev->timer_countdown = SKD_TIMER_MINUTES(20);
@@ -1426,7 +1426,7 @@ static void skd_resolve_req_exception(struct skd_device *skdev,
 	case SKD_CHECK_STATUS_REQUEUE_REQUEST:
 		if ((unsigned long) ++req->special < SKD_MAX_RETRIES) {
 			skd_log_skreq(skdev, skreq, "retry");
-			blk_requeue_request(skdev->queue, req);
+			blk_mq_requeue_request(req, true);
 			break;
 		}
 		/* fall through */
-- 
2.20.1

[PATCH AUTOSEL 4.19 043/237] amiflop: clean up on errors during setup

[Sasha Levin]

From: Omar Sandoval <osandov@fb.com>

[ Upstream commit 53d0f8dbde89cf6c862c7a62e00c6123e02cba41 ]

The error handling in fd_probe_drives() doesn't clean up at all. Fix it
up in preparation for converting to blk-mq. While we're here, get rid of
the commented out amiga_floppy_remove().

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/block/amiflop.c | 84 ++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 44 deletions(-)

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 3aaf6af3ec23d..2158e130744e0 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1701,11 +1701,41 @@ static const struct block_device_operations floppy_fops = {
 	.check_events	= amiga_check_events,
 };
 
+static struct gendisk *fd_alloc_disk(int drive)
+{
+	struct gendisk *disk;
+
+	disk = alloc_disk(1);
+	if (!disk)
+		goto out;
+
+	disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
+	if (IS_ERR(disk->queue)) {
+		disk->queue = NULL;
+		goto out_put_disk;
+	}
+
+	unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL);
+	if (!unit[drive].trackbuf)
+		goto out_cleanup_queue;
+
+	return disk;
+
+out_cleanup_queue:
+	blk_cleanup_queue(disk->queue);
+	disk->queue = NULL;
+out_put_disk:
+	put_disk(disk);
+out:
+	unit[drive].type->code = FD_NODRIVE;
+	return NULL;
+}
+
 static int __init fd_probe_drives(void)
 {
 	int drive,drives,nomem;
 
-	printk(KERN_INFO "FD: probing units\nfound ");
+	pr_info("FD: probing units\nfound");
 	drives=0;
 	nomem=0;
 	for(drive=0;drive<FD_MAX_UNITS;drive++) {
@@ -1713,27 +1743,17 @@ static int __init fd_probe_drives(void)
 		fd_probe(drive);
 		if (unit[drive].type->code == FD_NODRIVE)
 			continue;
-		disk = alloc_disk(1);
+
+		disk = fd_alloc_disk(drive);
 		if (!disk) {
-			unit[drive].type->code = FD_NODRIVE;
+			pr_cont(" no mem for fd%d", drive);
+			nomem = 1;
 			continue;
 		}
 		unit[drive].gendisk = disk;
-
-		disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
-		if (!disk->queue) {
-			unit[drive].type->code = FD_NODRIVE;
-			continue;
-		}
-
 		drives++;
-		if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
-			printk("no mem for ");
-			unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
-			drives--;
-			nomem = 1;
-		}
-		printk("fd%d ",drive);
+
+		pr_cont(" fd%d",drive);
 		disk->major = FLOPPY_MAJOR;
 		disk->first_minor = drive;
 		disk->fops = &floppy_fops;
@@ -1744,11 +1764,11 @@ static int __init fd_probe_drives(void)
 	}
 	if ((drives > 0) || (nomem == 0)) {
 		if (drives == 0)
-			printk("no drives");
-		printk("\n");
+			pr_cont(" no drives");
+		pr_cont("\n");
 		return drives;
 	}
-	printk("\n");
+	pr_cont("\n");
 	return -ENOMEM;
 }
  
@@ -1831,30 +1851,6 @@ static int __init amiga_floppy_probe(struct platform_device *pdev)
 	return ret;
 }
 
-#if 0 /* not safe to unload */
-static int __exit amiga_floppy_remove(struct platform_device *pdev)
-{
-	int i;
-
-	for( i = 0; i < FD_MAX_UNITS; i++) {
-		if (unit[i].type->code != FD_NODRIVE) {
-			struct request_queue *q = unit[i].gendisk->queue;
-			del_gendisk(unit[i].gendisk);
-			put_disk(unit[i].gendisk);
-			kfree(unit[i].trackbuf);
-			if (q)
-				blk_cleanup_queue(q);
-		}
-	}
-	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
-	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
-	free_irq(IRQ_AMIGA_DSKBLK, NULL);
-	custom.dmacon = DMAF_DISK; /* disable DMA */
-	amiga_chip_free(raw_buf);
-	unregister_blkdev(FLOPPY_MAJOR, "fd");
-}
-#endif
-
 static struct platform_driver amiga_floppy_driver = {
 	.driver   = {
 		.name	= "amiga-floppy",
-- 
2.20.1

[PATCH AUTOSEL 4.19 136/237] block: fix the DISCARD request merge

[Sasha Levin]

From: Jianchao Wang <jianchao.w.wang@oracle.com>

[ Upstream commit 69840466086d2248898020a08dda52732686c4e6 ]

There are two cases when handle DISCARD merge.
If max_discard_segments == 1, the bios/requests need to be contiguous
to merge. If max_discard_segments > 1, it takes every bio as a range
and different range needn't to be contiguous.

But now, attempt_merge screws this up. It always consider contiguity
for DISCARD for the case max_discard_segments > 1 and cannot merge
contiguous DISCARD for the case max_discard_segments == 1, because
rq_attempt_discard_merge always returns false in this case.
This patch fixes both of the two cases above.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 block/blk-merge.c | 46 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 10 deletions(-)

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 2e042190a4f1c..1dced51de1c6c 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -669,6 +669,31 @@ static void blk_account_io_merge(struct request *req)
 		part_stat_unlock();
 	}
 }
+/*
+ * Two cases of handling DISCARD merge:
+ * If max_discard_segments > 1, the driver takes every bio
+ * as a range and send them to controller together. The ranges
+ * needn't to be contiguous.
+ * Otherwise, the bios/requests will be handled as same as
+ * others which should be contiguous.
+ */
+static inline bool blk_discard_mergable(struct request *req)
+{
+	if (req_op(req) == REQ_OP_DISCARD &&
+	    queue_max_discard_segments(req->q) > 1)
+		return true;
+	return false;
+}
+
+enum elv_merge blk_try_req_merge(struct request *req, struct request *next)
+{
+	if (blk_discard_mergable(req))
+		return ELEVATOR_DISCARD_MERGE;
+	else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next))
+		return ELEVATOR_BACK_MERGE;
+
+	return ELEVATOR_NO_MERGE;
+}
 
 /*
  * For non-mq, this has to be called with the request spinlock acquired.
@@ -686,12 +711,6 @@ static struct request *attempt_merge(struct request_queue *q,
 	if (req_op(req) != req_op(next))
 		return NULL;
 
-	/*
-	 * not contiguous
-	 */
-	if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
-		return NULL;
-
 	if (rq_data_dir(req) != rq_data_dir(next)
 	    || req->rq_disk != next->rq_disk
 	    || req_no_special_merge(next))
@@ -715,11 +734,19 @@ static struct request *attempt_merge(struct request_queue *q,
 	 * counts here. Handle DISCARDs separately, as they
 	 * have separate settings.
 	 */
-	if (req_op(req) == REQ_OP_DISCARD) {
+
+	switch (blk_try_req_merge(req, next)) {
+	case ELEVATOR_DISCARD_MERGE:
 		if (!req_attempt_discard_merge(q, req, next))
 			return NULL;
-	} else if (!ll_merge_requests_fn(q, req, next))
+		break;
+	case ELEVATOR_BACK_MERGE:
+		if (!ll_merge_requests_fn(q, req, next))
+			return NULL;
+		break;
+	default:
 		return NULL;
+	}
 
 	/*
 	 * If failfast settings disagree or any of the two is already
@@ -843,8 +870,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 
 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio)
 {
-	if (req_op(rq) == REQ_OP_DISCARD &&
-	    queue_max_discard_segments(rq->q) > 1)
+	if (blk_discard_mergable(rq))
 		return ELEVATOR_DISCARD_MERGE;
 	else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector)
 		return ELEVATOR_BACK_MERGE;
-- 
2.20.1

[PATCH AUTOSEL 4.19 148/237] block: call rq_qos_exit() after queue is frozen

[Sasha Levin]

From: Ming Lei <ming.lei@redhat.com>

[ Upstream commit c57cdf7a9e51d97a43e29b8f4a04157875104000 ]

rq_qos_exit() removes the current q->rq_qos, this action has to be
done after queue is frozen, otherwise the IO queue path may never
be waken up, then IO hang is caused.

So fixes this issue by moving rq_qos_exit() after queue is frozen.

Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 block/blk-core.c  | 3 +++
 block/blk-sysfs.c | 2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 074ae9376189b..ea33d6abdcfc9 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -784,6 +784,9 @@ void blk_cleanup_queue(struct request_queue *q)
 	 * prevent that q->request_fn() gets invoked after draining finished.
 	 */
 	blk_freeze_queue(q);
+
+	rq_qos_exit(q);
+
 	spin_lock_irq(lock);
 	queue_flag_set(QUEUE_FLAG_DEAD, q);
 	spin_unlock_irq(lock);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index bab47a17b96f4..8286640d4d663 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -997,8 +997,6 @@ void blk_unregister_queue(struct gendisk *disk)
 	kobject_del(&q->kobj);
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
-	rq_qos_exit(q);
-
 	mutex_lock(&q->sysfs_lock);
 	if (q->request_fn || (q->mq_ops && q->elevator))
 		elv_unregister_queue(q);
-- 
2.20.1