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-rw-r--r--block/blk-exec.c2
-rw-r--r--block/blk-flush.c16
-rw-r--r--block/blk-lib.c82
-rw-r--r--block/blk-settings.c9
-rw-r--r--block/blk-sysfs.c3
-rw-r--r--block/blk.h21
-rw-r--r--block/elevator.c7
7 files changed, 69 insertions, 71 deletions
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 81e3181..8a0e7ec 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -56,7 +56,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
spin_lock_irq(q->queue_lock);
__elv_add_request(q, rq, where);
__blk_run_queue(q);
- /* the queue is stopped so it won't be plugged+unplugged */
+ /* the queue is stopped so it won't be run */
if (rq->cmd_type == REQ_TYPE_PM_RESUME)
q->request_fn(q);
spin_unlock_irq(q->queue_lock);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 6c9b5e1..bb21e4c 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -212,13 +212,19 @@ static void flush_end_io(struct request *flush_rq, int error)
}
/*
- * Moving a request silently to empty queue_head may stall the
- * queue. Kick the queue in those cases. This function is called
- * from request completion path and calling directly into
- * request_fn may confuse the driver. Always use kblockd.
+ * Kick the queue to avoid stall for two cases:
+ * 1. Moving a request silently to empty queue_head may stall the
+ * queue.
+ * 2. When flush request is running in non-queueable queue, the
+ * queue is hold. Restart the queue after flush request is finished
+ * to avoid stall.
+ * This function is called from request completion path and calling
+ * directly into request_fn may confuse the driver. Always use
+ * kblockd.
*/
- if (queued)
+ if (queued || q->flush_queue_delayed)
blk_run_queue_async(q);
+ q->flush_queue_delayed = 0;
}
/**
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 25de73e..78e627e 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -9,17 +9,20 @@
#include "blk.h"
-static void blkdev_discard_end_io(struct bio *bio, int err)
-{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
+struct bio_batch {
+ atomic_t done;
+ unsigned long flags;
+ struct completion *wait;
+};
- if (bio->bi_private)
- complete(bio->bi_private);
+static void bio_batch_end_io(struct bio *bio, int err)
+{
+ struct bio_batch *bb = bio->bi_private;
+ if (err && (err != -EOPNOTSUPP))
+ clear_bit(BIO_UPTODATE, &bb->flags);
+ if (atomic_dec_and_test(&bb->done))
+ complete(bb->wait);
bio_put(bio);
}
@@ -41,6 +44,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
struct request_queue *q = bdev_get_queue(bdev);
int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
+ struct bio_batch bb;
struct bio *bio;
int ret = 0;
@@ -67,7 +71,11 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
type |= REQ_SECURE;
}
- while (nr_sects && !ret) {
+ atomic_set(&bb.done, 1);
+ bb.flags = 1 << BIO_UPTODATE;
+ bb.wait = &wait;
+
+ while (nr_sects) {
bio = bio_alloc(gfp_mask, 1);
if (!bio) {
ret = -ENOMEM;
@@ -75,9 +83,9 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
}
bio->bi_sector = sector;
- bio->bi_end_io = blkdev_discard_end_io;
+ bio->bi_end_io = bio_batch_end_io;
bio->bi_bdev = bdev;
- bio->bi_private = &wait;
+ bio->bi_private = &bb;
if (nr_sects > max_discard_sectors) {
bio->bi_size = max_discard_sectors << 9;
@@ -88,45 +96,21 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
nr_sects = 0;
}
- bio_get(bio);
+ atomic_inc(&bb.done);
submit_bio(type, bio);
+ }
+ /* Wait for bios in-flight */
+ if (!atomic_dec_and_test(&bb.done))
wait_for_completion(&wait);
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
- ret = -EIO;
- bio_put(bio);
- }
+ if (!test_bit(BIO_UPTODATE, &bb.flags))
+ ret = -EIO;
return ret;
}
EXPORT_SYMBOL(blkdev_issue_discard);
-struct bio_batch
-{
- atomic_t done;
- unsigned long flags;
- struct completion *wait;
-};
-
-static void bio_batch_end_io(struct bio *bio, int err)
-{
- struct bio_batch *bb = bio->bi_private;
-
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bb->flags);
- else
- clear_bit(BIO_UPTODATE, &bb->flags);
- }
- if (bb)
- if (atomic_dec_and_test(&bb->done))
- complete(bb->wait);
- bio_put(bio);
-}
-
/**
* blkdev_issue_zeroout - generate number of zero filed write bios
* @bdev: blockdev to issue
@@ -151,7 +135,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
bb.flags = 1 << BIO_UPTODATE;
bb.wait = &wait;
-submit:
ret = 0;
while (nr_sects != 0) {
bio = bio_alloc(gfp_mask,
@@ -168,9 +151,6 @@ submit:
while (nr_sects != 0) {
sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
- if (sz == 0)
- /* bio has maximum size possible */
- break;
ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
nr_sects -= ret >> 9;
sector += ret >> 9;
@@ -190,16 +170,6 @@ submit:
/* One of bios in the batch was completed with error.*/
ret = -EIO;
- if (ret)
- goto out;
-
- if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
- if (nr_sects != 0)
- goto submit;
-out:
return ret;
}
EXPORT_SYMBOL(blkdev_issue_zeroout);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 1fa7692..fa1eb04 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -120,7 +120,7 @@ void blk_set_default_limits(struct queue_limits *lim)
lim->discard_granularity = 0;
lim->discard_alignment = 0;
lim->discard_misaligned = 0;
- lim->discard_zeroes_data = -1;
+ lim->discard_zeroes_data = 1;
lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
lim->alignment_offset = 0;
@@ -166,6 +166,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
blk_set_default_limits(&q->limits);
blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS);
+ q->limits.discard_zeroes_data = 0;
/*
* by default assume old behaviour and bounce for any highmem page
@@ -790,6 +791,12 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush)
}
EXPORT_SYMBOL_GPL(blk_queue_flush);
+void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
+{
+ q->flush_not_queueable = !queueable;
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index bd23631..d935bd8 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -152,7 +152,8 @@ static ssize_t queue_discard_granularity_show(struct request_queue *q, char *pag
static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
{
- return queue_var_show(q->limits.max_discard_sectors << 9, page);
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_discard_sectors << 9);
}
static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
diff --git a/block/blk.h b/block/blk.h
index 6126346..1f798b5 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -61,7 +61,26 @@ static inline struct request *__elv_next_request(struct request_queue *q)
rq = list_entry_rq(q->queue_head.next);
return rq;
}
-
+ /*
+ * Flush request is running and flush request isn't queueable
+ * in the drive, we can hold the queue till flush request is
+ * finished. Even we don't do this, driver can't dispatch next
+ * requests and will requeue them. And this can improve
+ * throughput too. For example, we have request flush1, write1,
+ * flush 2. flush1 is dispatched, then queue is hold, write1
+ * isn't inserted to queue. After flush1 is finished, flush2
+ * will be dispatched. Since disk cache is already clean,
+ * flush2 will be finished very soon, so looks like flush2 is
+ * folded to flush1.
+ * Since the queue is hold, a flag is set to indicate the queue
+ * should be restarted later. Please see flush_end_io() for
+ * details.
+ */
+ if (q->flush_pending_idx != q->flush_running_idx &&
+ !queue_flush_queueable(q)) {
+ q->flush_queue_delayed = 1;
+ return NULL;
+ }
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
return NULL;
}
diff --git a/block/elevator.c b/block/elevator.c
index 45ca1e3..2a0b653 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -155,13 +155,8 @@ static struct elevator_type *elevator_get(const char *name)
e = elevator_find(name);
if (!e) {
- char elv[ELV_NAME_MAX + strlen("-iosched")];
-
spin_unlock(&elv_list_lock);
-
- snprintf(elv, sizeof(elv), "%s-iosched", name);
-
- request_module("%s", elv);
+ request_module("%s-iosched", name);
spin_lock(&elv_list_lock);
e = elevator_find(name);
}
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