dm ebs: pass discards down to underlying device (a5089a95) · Commits · 戴 / test

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,

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