![Ben Hutchings](/assets/img/avatar_default.png)
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
213 lines
4.5 KiB
C
213 lines
4.5 KiB
C
/*
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* Functions related to generic helpers functions
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/scatterlist.h>
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#include "blk.h"
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static void blkdev_discard_end_io(struct bio *bio, int err)
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{
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if (err) {
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if (err == -EOPNOTSUPP)
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set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
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clear_bit(BIO_UPTODATE, &bio->bi_flags);
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}
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if (bio->bi_private)
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complete(bio->bi_private);
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bio_put(bio);
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}
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/**
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* blkdev_issue_discard - queue a discard
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* @bdev: blockdev to issue discard for
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* @sector: start sector
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* @nr_sects: number of sectors to discard
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* @gfp_mask: memory allocation flags (for bio_alloc)
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* @flags: BLKDEV_IFL_* flags to control behaviour
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*
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* Description:
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* Issue a discard request for the sectors in question.
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*/
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int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
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{
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DECLARE_COMPLETION_ONSTACK(wait);
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struct request_queue *q = bdev_get_queue(bdev);
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int type = REQ_WRITE | REQ_DISCARD;
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unsigned int max_discard_sectors;
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struct bio *bio;
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int ret = 0;
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if (!q)
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return -ENXIO;
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if (!blk_queue_discard(q))
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return -EOPNOTSUPP;
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/*
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* Ensure that max_discard_sectors is of the proper
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* granularity
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*/
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max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
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if (q->limits.discard_granularity) {
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unsigned int disc_sects = q->limits.discard_granularity >> 9;
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max_discard_sectors &= ~(disc_sects - 1);
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}
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if (flags & BLKDEV_DISCARD_SECURE) {
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if (!blk_queue_secdiscard(q))
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return -EOPNOTSUPP;
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type |= REQ_SECURE;
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}
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while (nr_sects && !ret) {
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bio = bio_alloc(gfp_mask, 1);
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if (!bio) {
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ret = -ENOMEM;
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break;
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}
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bio->bi_sector = sector;
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bio->bi_end_io = blkdev_discard_end_io;
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bio->bi_bdev = bdev;
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bio->bi_private = &wait;
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if (nr_sects > max_discard_sectors) {
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bio->bi_size = max_discard_sectors << 9;
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nr_sects -= max_discard_sectors;
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sector += max_discard_sectors;
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} else {
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bio->bi_size = nr_sects << 9;
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nr_sects = 0;
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}
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bio_get(bio);
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submit_bio(type, bio);
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wait_for_completion(&wait);
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if (bio_flagged(bio, BIO_EOPNOTSUPP))
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ret = -EOPNOTSUPP;
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else if (!bio_flagged(bio, BIO_UPTODATE))
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ret = -EIO;
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bio_put(bio);
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}
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return ret;
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}
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EXPORT_SYMBOL(blkdev_issue_discard);
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struct bio_batch
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{
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atomic_t done;
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unsigned long flags;
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struct completion *wait;
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bio_end_io_t *end_io;
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};
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static void bio_batch_end_io(struct bio *bio, int err)
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{
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struct bio_batch *bb = bio->bi_private;
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if (err) {
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if (err == -EOPNOTSUPP)
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set_bit(BIO_EOPNOTSUPP, &bb->flags);
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else
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clear_bit(BIO_UPTODATE, &bb->flags);
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}
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if (bb) {
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if (bb->end_io)
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bb->end_io(bio, err);
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atomic_inc(&bb->done);
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complete(bb->wait);
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}
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bio_put(bio);
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}
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/**
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* blkdev_issue_zeroout - generate number of zero filed write bios
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* @bdev: blockdev to issue
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* @sector: start sector
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* @nr_sects: number of sectors to write
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* @gfp_mask: memory allocation flags (for bio_alloc)
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*
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* Description:
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* Generate and issue number of bios with zerofiled pages.
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* Send barrier at the beginning and at the end if requested. This guarantie
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* correct request ordering. Empty barrier allow us to avoid post queue flush.
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*/
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int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
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sector_t nr_sects, gfp_t gfp_mask)
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{
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int ret;
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struct bio *bio;
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struct bio_batch bb;
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unsigned int sz, issued = 0;
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DECLARE_COMPLETION_ONSTACK(wait);
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atomic_set(&bb.done, 0);
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bb.flags = 1 << BIO_UPTODATE;
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bb.wait = &wait;
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bb.end_io = NULL;
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submit:
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ret = 0;
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while (nr_sects != 0) {
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bio = bio_alloc(gfp_mask,
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min(nr_sects, (sector_t)BIO_MAX_PAGES));
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if (!bio) {
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ret = -ENOMEM;
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break;
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}
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bio->bi_sector = sector;
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bio->bi_bdev = bdev;
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bio->bi_end_io = bio_batch_end_io;
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bio->bi_private = &bb;
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while (nr_sects != 0) {
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sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
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if (sz == 0)
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/* bio has maximum size possible */
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break;
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ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
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nr_sects -= ret >> 9;
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sector += ret >> 9;
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if (ret < (sz << 9))
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break;
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}
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ret = 0;
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issued++;
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submit_bio(WRITE, bio);
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}
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/* Wait for bios in-flight */
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while (issued != atomic_read(&bb.done))
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wait_for_completion(&wait);
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if (!test_bit(BIO_UPTODATE, &bb.flags))
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/* One of bios in the batch was completed with error.*/
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ret = -EIO;
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if (ret)
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goto out;
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if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
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ret = -EOPNOTSUPP;
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goto out;
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}
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if (nr_sects != 0)
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goto submit;
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out:
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return ret;
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}
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EXPORT_SYMBOL(blkdev_issue_zeroout);
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