Commit a5089a95 authored by Heinz Mauelshagen's avatar Heinz Mauelshagen Committed by Mike Snitzer
Browse files

dm ebs: pass discards down to underlying device 



Make use of dm_bufio_issue_discard() to pass discards down to the
underlying device.

Signed-off-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 6fbeb004

drivers/md/dm-ebs-target.c

+34 −7
Original line number Diff line number Diff line
@@ -132,16 +132,43 @@ static int __ebs_rw_bio(struct ebs_c *ec, int rw, struct bio *bio) 
	return r;

}



/* 'Discard' blocks, i.e. release them from the bufio cache. */

static int __ebs_forget_bio(struct ebs_c *ec, struct bio *bio)

/*

 * Discard bio's blocks, i.e. pass discards down.

 *

 * Avoid discarding partial blocks at beginning and end;

 * return 0 in case no blocks can be discarded as a result.

 */

static int __ebs_discard_bio(struct ebs_c *ec, struct bio *bio)

{

	sector_t block, blocks, sector = bio->bi_iter.bi_sector;



	block = __sector_to_block(ec, sector);

	blocks = __nr_blocks(ec, bio);



	/*

	 * Partial first underlying block (__nr_blocks() may have

	 * resulted in one block).

	 */

	if (__block_mod(sector, ec->u_bs)) {

		block++;

		blocks--;

	}



	/* Partial last underlying block if any. */

	if (blocks && __block_mod(bio_end_sector(bio), ec->u_bs))

		blocks--;



	return blocks ? dm_bufio_issue_discard(ec->bufio, block, blocks) : 0;

}



/* Release blocks them from the bufio cache. */

static void __ebs_forget_bio(struct ebs_c *ec, struct bio *bio)

{

	sector_t blocks, sector = bio->bi_iter.bi_sector;



	blocks = __nr_blocks(ec, bio);

	for (; blocks--; sector += ec->u_bs)

		dm_bufio_forget(ec->bufio, __sector_to_block(ec, sector));



	return 0;

}



/* Worker funtion to process incoming bios. */
@@ -183,8 +210,8 @@ static void __ebs_process_bios(struct work_struct *ws) 
			write = true;

			r = __ebs_rw_bio(ec, WRITE, bio);

		} else if (bio_op(bio) == REQ_OP_DISCARD) {

			/* FIXME: (optionally) call dm_bufio_discard_buffers() once upstream. */

			r = __ebs_forget_bio(ec, bio);

			__ebs_forget_bio(ec, bio);

			r = __ebs_discard_bio(ec, bio);

		}



		if (r < 0)
@@ -409,7 +436,7 @@ static int ebs_iterate_devices(struct dm_target *ti, 


static struct target_type ebs_target = {

	.name		 = "ebs",

	.version	 = {1, 0, 0},

	.version	 = {1, 0, 1},

	.features	 = DM_TARGET_PASSES_INTEGRITY,

	.module		 = THIS_MODULE,

	.ctr		 = ebs_ctr,