| /* |
| * 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" |
| |
| 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); |
| |
| 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 = REQ_WRITE | REQ_DISCARD; |
| unsigned int max_discard_sectors; |
| struct bio *bio; |
| int ret = 0; |
| |
| if (!q) |
| return -ENXIO; |
| |
| if (!blk_queue_discard(q)) |
| return -EOPNOTSUPP; |
| |
| /* |
| * Ensure that max_discard_sectors is of the proper |
| * granularity |
| */ |
| max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); |
| if (q->limits.discard_granularity) { |
| unsigned int disc_sects = q->limits.discard_granularity >> 9; |
| |
| max_discard_sectors &= ~(disc_sects - 1); |
| } |
| |
| if (flags & BLKDEV_DISCARD_SECURE) { |
| if (!blk_queue_secdiscard(q)) |
| return -EOPNOTSUPP; |
| type |= REQ_SECURE; |
| } |
| |
| while (nr_sects && !ret) { |
| bio = bio_alloc(gfp_mask, 1); |
| if (!bio) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| bio->bi_sector = sector; |
| bio->bi_end_io = blkdev_discard_end_io; |
| bio->bi_bdev = bdev; |
| bio->bi_private = &wait; |
| |
| 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); |
| |
| 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; |
| } |
| EXPORT_SYMBOL(blkdev_issue_discard); |
| |
| 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) |
| * |
| * Description: |
| * Generate and issue number of bios with zerofiled pages. |
| */ |
| |
| int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
| sector_t nr_sects, gfp_t gfp_mask) |
| { |
| int ret; |
| 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; |
| |
| submit: |
| ret = 0; |
| while (nr_sects != 0) { |
| bio = bio_alloc(gfp_mask, |
| min(nr_sects, (sector_t)BIO_MAX_PAGES)); |
| if (!bio) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| bio->bi_sector = sector; |
| bio->bi_bdev = bdev; |
| bio->bi_end_io = bio_batch_end_io; |
| bio->bi_private = &bb; |
| |
| 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; |
| if (ret < (sz << 9)) |
| break; |
| } |
| ret = 0; |
| issued++; |
| submit_bio(WRITE, bio); |
| } |
| |
| /* 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); |