with the previous I/O request are enabled. When set to 2,
all merge tries are disabled. The default value is 0 -
which enables all types of merge tries.
+
+What: /sys/block/<disk>/discard_alignment
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space in units that are bigger than
+ the exported logical block size. The discard_alignment
+ parameter indicates how many bytes the beginning of the
+ device is offset from the internal allocation unit's
+ natural alignment.
+
+What: /sys/block/<disk>/<partition>/discard_alignment
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space in units that are bigger than
+ the exported logical block size. The discard_alignment
+ parameter indicates how many bytes the beginning of the
+ partition is offset from the internal allocation unit's
+ natural alignment.
+
+What: /sys/block/<disk>/queue/discard_granularity
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space using units that are bigger
+ than the logical block size. The discard_granularity
+ parameter indicates the size of the internal allocation
+ unit in bytes if reported by the device. Otherwise the
+ discard_granularity will be set to match the device's
+ physical block size. A discard_granularity of 0 means
+ that the device does not support discard functionality.
+
+What: /sys/block/<disk>/queue/discard_max_bytes
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may have
+ internal limits on the number of bytes that can be
+ trimmed or unmapped in a single operation. Some storage
+ protocols also have inherent limits on the number of
+ blocks that can be described in a single command. The
+ discard_max_bytes parameter is set by the device driver
+ to the maximum number of bytes that can be discarded in
+ a single operation. Discard requests issued to the
+ device must not exceed this limit. A discard_max_bytes
+ value of 0 means that the device does not support
+ discard functionality.
+
+What: /sys/block/<disk>/queue/discard_zeroes_data
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may return
+ stale or random data when a previously discarded block
+ is read back. This can cause problems if the filesystem
+ expects discarded blocks to be explicitly cleared. If a
+ device reports that it deterministically returns zeroes
+ when a discarded area is read the discard_zeroes_data
+ parameter will be set to one. Otherwise it will be 0 and
+ the result of reading a discarded area is undefined.
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);
}
/*
- * 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;
}
/**
#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);
}
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;
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;
}
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;
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
bb.flags = 1 << BIO_UPTODATE;
bb.wait = &wait;
-submit:
ret = 0;
while (nr_sects != 0) {
bio = bio_alloc(gfp_mask,
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;
/* 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);
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;
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
}
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;
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)
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;
}
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);
}
static int ata_scsi_dev_config(struct scsi_device *sdev,
struct ata_device *dev)
{
+ struct request_queue *q = sdev->request_queue;
+
if (!ata_id_has_unload(dev->id))
dev->flags |= ATA_DFLAG_NO_UNLOAD;
/* configure max sectors */
- blk_queue_max_hw_sectors(sdev->request_queue, dev->max_sectors);
+ blk_queue_max_hw_sectors(q, dev->max_sectors);
if (dev->class == ATA_DEV_ATAPI) {
- struct request_queue *q = sdev->request_queue;
void *buf;
sdev->sector_size = ATA_SECT_SIZE;
/* set DMA padding */
- blk_queue_update_dma_pad(sdev->request_queue,
- ATA_DMA_PAD_SZ - 1);
+ blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);
/* configure draining */
buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
"sector_size=%u > PAGE_SIZE, PIO may malfunction\n",
sdev->sector_size);
- blk_queue_update_dma_alignment(sdev->request_queue,
- sdev->sector_size - 1);
+ blk_queue_update_dma_alignment(q, sdev->sector_size - 1);
if (dev->flags & ATA_DFLAG_AN)
set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
}
+ blk_queue_flush_queueable(q, false);
+
dev->sdev = sdev;
return 0;
}
disk->first_minor = unit;
strcpy(disk->disk_name, cd->name); /* umm... */
disk->fops = &pcd_bdops;
+ disk->flags = GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+ disk->events = DISK_EVENT_MEDIA_CHANGE;
}
}
blk_queue_max_hw_sectors(q, 4096 / 512);
gendisk->queue = q;
gendisk->fops = &viocd_fops;
- gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE;
+ gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
+ GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+ gendisk->events = DISK_EVENT_MEDIA_CHANGE;
set_capacity(gendisk, 0);
gendisk->private_data = d;
d->viocd_disk = gendisk;
ide_cd_read_toc(drive, &sense);
g->fops = &idecd_ops;
- g->flags |= GENHD_FL_REMOVABLE;
+ g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+ g->events = DISK_EVENT_MEDIA_CHANGE;
add_disk(g);
return 0;
disk->first_minor = minor;
sprintf(disk->disk_name, "sr%d", minor);
disk->fops = &sr_bdops;
- disk->flags = GENHD_FL_CD;
+ disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
res = __blkdev_get(bdev, mode, 0);
if (whole) {
+ struct gendisk *disk = whole->bd_disk;
+
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
spin_unlock(&bdev_lock);
/*
- * Block event polling for write claims. Any write
- * holder makes the write_holder state stick until all
- * are released. This is good enough and tracking
- * individual writeable reference is too fragile given
- * the way @mode is used in blkdev_get/put().
+ * Block event polling for write claims if requested. Any
+ * write holder makes the write_holder state stick until
+ * all are released. This is good enough and tracking
+ * individual writeable reference is too fragile given the
+ * way @mode is used in blkdev_get/put().
*/
- if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+ if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
+ !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
bdev->bd_write_holder = true;
- disk_block_events(bdev->bd_disk);
+ disk_block_events(disk);
}
mutex_unlock(&bdev->bd_mutex);
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
- return sprintf(buf, "%u\n", p->discard_alignment);
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%u\n",
+ queue_limit_discard_alignment(&disk->queue->limits,
+ p->start_sect));
}
ssize_t part_stat_show(struct device *dev,
p->start_sect = start;
p->alignment_offset =
queue_limit_alignment_offset(&disk->queue->limits, start);
- p->discard_alignment =
- queue_limit_discard_alignment(&disk->queue->limits, start);
p->nr_sects = len;
p->partno = partno;
p->policy = get_disk_ro(disk);
unsigned char misaligned;
unsigned char discard_misaligned;
unsigned char cluster;
- signed char discard_zeroes_data;
+ unsigned char discard_zeroes_data;
};
struct request_queue
* for flush operations
*/
unsigned int flush_flags;
+ unsigned int flush_not_queueable:1;
+ unsigned int flush_queue_delayed:1;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
unsigned long flush_pending_since;
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
+extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
{
unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
+ if (!lim->max_discard_sectors)
+ return 0;
+
return (lim->discard_granularity + lim->discard_alignment - alignment)
& (lim->discard_granularity - 1);
}
static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
{
- if (q->limits.discard_zeroes_data == 1)
+ if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
return 1;
return 0;
return bdev->bd_block_size;
}
+static inline bool queue_flush_queueable(struct request_queue *q)
+{
+ return !q->flush_not_queueable;
+}
+
typedef struct {struct page *v;} Sector;
unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
sector_t start_sect;
sector_t nr_sects;
sector_t alignment_offset;
- unsigned int discard_alignment;
struct device __dev;
struct kobject *holder_dir;
int policy, partno;
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY 128
+#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
enum {
DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
projects / karo-tx-linux.git / commitdiff