clear_bit(BIO_UPTODATE, &bio->bi_flags);
}
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ __free_page(bio_page(bio));
+
bio_put(bio);
}
* @sector: start sector
* @nr_sects: number of sectors to discard
* @gfp_mask: memory allocation flags (for bio_alloc)
+ * @flags: DISCARD_FL_* flags to control behaviour
*
* Description:
- * Issue a discard request for the sectors in question. Does not wait.
+ * 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)
+int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, int flags)
{
- struct request_queue *q;
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request_queue *q = bdev_get_queue(bdev);
+ int type = flags & DISCARD_FL_BARRIER ?
+ DISCARD_BARRIER : DISCARD_NOBARRIER;
struct bio *bio;
+ struct page *page;
int ret = 0;
- if (bdev->bd_disk == NULL)
- return -ENXIO;
-
- q = bdev_get_queue(bdev);
if (!q)
return -ENXIO;
- if (!q->prepare_discard_fn)
+ if (!blk_queue_discard(q))
return -EOPNOTSUPP;
while (nr_sects && !ret) {
- bio = bio_alloc(gfp_mask, 0);
- if (!bio)
- return -ENOMEM;
+ 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 & DISCARD_FL_WAIT)
+ bio->bi_private = &wait;
- bio->bi_sector = sector;
+ /*
+ * 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;
- if (nr_sects > q->max_hw_sectors) {
- bio->bi_size = q->max_hw_sectors << 9;
- nr_sects -= q->max_hw_sectors;
- sector += q->max_hw_sectors;
+ /*
+ * 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(DISCARD_BARRIER, bio);
+ submit_bio(type, bio);
+
+ if (flags & DISCARD_FL_WAIT)
+ wait_for_completion(&wait);
- /* Check if it failed immediately */
if (bio_flagged(bio, BIO_EOPNOTSUPP))
ret = -EOPNOTSUPP;
else if (!bio_flagged(bio, BIO_UPTODATE))
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);