Messages in this thread Patch in this message | | | From | Dmitry Monakhov <> | Subject | [PATCH 3/6] blkdev: add blkdev_issue helper functions | Date | Mon, 29 Mar 2010 10:09:22 +0400 |
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Move blkdev_issue_discard from blk-barrier.c because it is not barrier related.
Add new helper functions: __blkdev_issue_zeroout: Explicitly zero given range via zeroed write request. This function is useful in many places.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> --- block/Makefile | 2 +- block/blk-barrier.c | 103 --------------------- block/blk-lib.c | 232 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 3 +- 4 files changed, 235 insertions(+), 105 deletions(-) create mode 100644 block/blk-lib.c
diff --git a/block/Makefile b/block/Makefile index cb2d515..0bb499a 100644 --- a/block/Makefile +++ b/block/Makefile @@ -5,7 +5,7 @@ obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \ blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \ - blk-iopoll.o ioctl.o genhd.o scsi_ioctl.o + blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o obj-$(CONFIG_BLK_DEV_BSG) += bsg.o obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o diff --git a/block/blk-barrier.c b/block/blk-barrier.c index 56254b1..1242bdd 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -347,106 +347,3 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask, } EXPORT_SYMBOL(blkdev_issue_flush); -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); - } - - if (bio->bi_private) - complete(bio->bi_private); - __free_page(bio_page(bio)); - - bio_put(bio); -} - -/** - * blkdev_issue_discard - queue a discard - * @bdev: blockdev to issue discard for - * @sector: start sector - * @nr_sects: number of sectors to discard - * @gfp_mask: memory allocation flags (for bio_alloc) - * @flags: BLKDEV_IFL_* flags to control behaviour - * - * Description: - * Issue a discard request for the sectors in question. - */ -int blkdev_issue_discard(struct block_device *bdev, sector_t sector, - sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) -{ - DECLARE_COMPLETION_ONSTACK(wait); - struct request_queue *q = bdev_get_queue(bdev); - int type = flags & BLKDEV_IFL_BARRIER ? - DISCARD_BARRIER : DISCARD_NOBARRIER; - struct bio *bio; - struct page *page; - int ret = 0; - - if (!q) - return -ENXIO; - - if (!blk_queue_discard(q)) - return -EOPNOTSUPP; - - while (nr_sects && !ret) { - unsigned int sector_size = q->limits.logical_block_size; - unsigned int max_discard_sectors = - min(q->limits.max_discard_sectors, UINT_MAX >> 9); - - bio = bio_alloc(gfp_mask, 1); - if (!bio) - goto out; - bio->bi_sector = sector; - bio->bi_end_io = blkdev_discard_end_io; - bio->bi_bdev = bdev; - if (flags & BLKDEV_IFL_BARRIER) - bio->bi_private = &wait; - - /* - * Add a zeroed one-sector payload as that's what - * our current implementations need. If we'll ever need - * more the interface will need revisiting. - */ - page = alloc_page(gfp_mask | __GFP_ZERO); - if (!page) - goto out_free_bio; - if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size) - goto out_free_page; - - /* - * And override the bio size - the way discard works we - * touch many more blocks on disk than the actual payload - * length. - */ - if (nr_sects > max_discard_sectors) { - bio->bi_size = max_discard_sectors << 9; - nr_sects -= max_discard_sectors; - sector += max_discard_sectors; - } else { - bio->bi_size = nr_sects << 9; - nr_sects = 0; - } - - bio_get(bio); - submit_bio(type, bio); - - if (flags & BLKDEV_IFL_BARRIER) - wait_for_completion(&wait); - - if (bio_flagged(bio, BIO_EOPNOTSUPP)) - ret = -EOPNOTSUPP; - else if (!bio_flagged(bio, BIO_UPTODATE)) - ret = -EIO; - bio_put(bio); - } - return ret; -out_free_page: - __free_page(page); -out_free_bio: - bio_put(bio); -out: - return -ENOMEM; -} -EXPORT_SYMBOL(blkdev_issue_discard); diff --git a/block/blk-lib.c b/block/blk-lib.c new file mode 100644 index 0000000..d0f84f6 --- /dev/null +++ b/block/blk-lib.c @@ -0,0 +1,232 @@ +/* + * Functions related to generic helpers functions + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/scatterlist.h> + +#include "blk.h" + +struct bio_batch +{ + atomic_t done; + unsigned long flags; + struct completion *wait; + bio_end_io_t *end_io; +}; + +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 (bb->end_io) + bb->end_io(bio, err); + atomic_inc(&bb->done); + complete(bb->wait); + } + bio_put(bio); +} + +/** + * __blkdev_issue_zeroout generate number of zero filed write bios + * @bdev: blockdev to issue + * @sector: start sector + * @nr_sects: number of sectors to write + * @gfp_mask: memory allocation flags (for bio_alloc) + * @flags: BLKDEV_IFL_* flags to control behaviour + * + * Description: + * Generate and issue number of bios with zerofiled pages. + * Send barrier at the beginning and at the end if requested. This guarantie + * correct request ordering. Empty barrier allow us to avoid post queue flush. + */ + +int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, + sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) +{ + int ret = 0; + struct bio *bio; + struct bio_batch bb; + unsigned int sz, issued = 0; + DECLARE_COMPLETION_ONSTACK(wait); + + atomic_set(&bb.done, 0); + bb.flags = 1 << BIO_UPTODATE; + bb.wait = &wait; + bb.end_io = NULL; + + if (flags & BLKDEV_IFL_BARRIER) { + /* issue async barrier before the data */ + ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0); + if (ret) + return ret; + } +submit: + while (nr_sects != 0) { + bio = bio_alloc(gfp_mask, + min(nr_sects, (sector_t)BIO_MAX_PAGES)); + if (!bio) + break; + + bio->bi_sector = sector; + bio->bi_bdev = bdev; + bio->bi_end_io = bio_batch_end_io; + if (flags & BLKDEV_IFL_WAIT) + bio->bi_private = &bb; + + while(nr_sects != 0) { + sz = min(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; + if (ret < (sz << 9)) + break; + } + issued++; + submit_bio(WRITE, bio); + } + /* + * When all data bios are in flight. Send final barrier if requeted. + */ + if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER) + ret = blkdev_issue_flush(bdev, gfp_mask, NULL, + flags & BLKDEV_IFL_WAIT); + + + if (flags & BLKDEV_IFL_WAIT) + /* Wait for bios in-flight */ + while ( issued != atomic_read(&bb.done)) + wait_for_completion(&wait); + + if (!test_bit(BIO_UPTODATE, &bb.flags)) + /* 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); + +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); + } + + if (bio->bi_private) + complete(bio->bi_private); + __free_page(bio_page(bio)); + + bio_put(bio); +} + +/** + * blkdev_issue_discard - queue a discard + * @bdev: blockdev to issue discard for + * @sector: start sector + * @nr_sects: number of sectors to discard + * @gfp_mask: memory allocation flags (for bio_alloc) + * @flags: BLKDEV_IFL_* flags to control behaviour + * + * Description: + * Issue a discard request for the sectors in question. + */ +int blkdev_issue_discard(struct block_device *bdev, sector_t sector, + sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) +{ + DECLARE_COMPLETION_ONSTACK(wait); + struct request_queue *q = bdev_get_queue(bdev); + int type = flags & BLKDEV_IFL_BARRIER ? + DISCARD_BARRIER : DISCARD_NOBARRIER; + struct bio *bio; + struct page *page; + int ret = 0; + + if (!q) + return -ENXIO; + + if (!blk_queue_discard(q)) + return -EOPNOTSUPP; + + while (nr_sects && !ret) { + unsigned int sector_size = q->limits.logical_block_size; + unsigned int max_discard_sectors = + min(q->limits.max_discard_sectors, UINT_MAX >> 9); + + bio = bio_alloc(gfp_mask, 1); + if (!bio) + goto out; + bio->bi_sector = sector; + bio->bi_end_io = blkdev_discard_end_io; + bio->bi_bdev = bdev; + if (flags & BLKDEV_IFL_BARRIER) + bio->bi_private = &wait; + + /* + * Add a zeroed one-sector payload as that's what + * our current implementations need. If we'll ever need + * more the interface will need revisiting. + */ + page = alloc_page(gfp_mask | __GFP_ZERO); + if (!page) + goto out_free_bio; + if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size) + goto out_free_page; + + /* + * And override the bio size - the way discard works we + * touch many more blocks on disk than the actual payload + * length. + */ + if (nr_sects > max_discard_sectors) { + bio->bi_size = max_discard_sectors << 9; + nr_sects -= max_discard_sectors; + sector += max_discard_sectors; + } else { + bio->bi_size = nr_sects << 9; + nr_sects = 0; + } + + bio_get(bio); + submit_bio(type, bio); + + if (flags & BLKDEV_IFL_BARRIER) + wait_for_completion(&wait); + + if (bio_flagged(bio, BIO_EOPNOTSUPP)) + ret = -EOPNOTSUPP; + else if (!bio_flagged(bio, BIO_UPTODATE)) + ret = -EIO; + bio_put(bio); + } + return ret; +out_free_page: + __free_page(page); +out_free_bio: + bio_put(bio); +out: + return -ENOMEM; +} +EXPORT_SYMBOL(blkdev_issue_discard); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 84ec105..8bc6966 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1022,7 +1022,8 @@ extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *, unsigned long); extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); - +extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, + sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); static inline int sb_issue_discard(struct super_block *sb, sector_t block, sector_t nr_blocks) { -- 1.6.6.1
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