Commit 3d7f4562 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: fix __send_changing_extent_only() to send first bio and chain remainder 



__send_changing_extent_only() must follow the same pattern that was
established with commit "dm: ensure bio submission follows a depth-first
tree walk".  That is: submit first bio up to split boundary and then
split the remainder to further submissions.

Suggested-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 0776aa0e

drivers/md/dm.c

+30 −36
Original line number Diff line number Diff line
@@ -1348,19 +1348,13 @@ static bool is_split_required_for_discard(struct dm_target *ti) 
	return ti->split_discard_bios;

}



static int __send_changing_extent_only(struct clone_info *ci,

static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,

				       get_num_bios_fn get_num_bios,

				       is_split_required_fn is_split_required)

{

	struct dm_target *ti;

	unsigned len;

	unsigned num_bios;



	do {

		ti = dm_table_find_target(ci->map, ci->sector);

		if (!dm_target_is_valid(ti))

			return -EIO;



	/*

	 * Even though the device advertised support for this type of

	 * request, that does not mean every target supports it, and
@@ -1379,25 +1373,25 @@ static int __send_changing_extent_only(struct clone_info *ci, 
	__send_duplicate_bios(ci, ti, num_bios, &len);



	ci->sector += len;

	} while (ci->sector_count -= len);

	ci->sector_count -= len;



	return 0;

}



static int __send_discard(struct clone_info *ci)

static int __send_discard(struct clone_info *ci, struct dm_target *ti)

{

	return __send_changing_extent_only(ci, get_num_discard_bios,

	return __send_changing_extent_only(ci, ti, get_num_discard_bios,

					   is_split_required_for_discard);

}



static int __send_write_same(struct clone_info *ci)

static int __send_write_same(struct clone_info *ci, struct dm_target *ti)

{

	return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);

	return __send_changing_extent_only(ci, ti, get_num_write_same_bios, NULL);

}



static int __send_write_zeroes(struct clone_info *ci)

static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)

{

	return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);

	return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios, NULL);

}



/*
@@ -1410,17 +1404,17 @@ static int __split_and_process_non_flush(struct clone_info *ci) 
	unsigned len;

	int r;



	if (unlikely(bio_op(bio) == REQ_OP_DISCARD))

		return __send_discard(ci);

	else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))

		return __send_write_same(ci);

	else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))

		return __send_write_zeroes(ci);



	ti = dm_table_find_target(ci->map, ci->sector);

	if (!dm_target_is_valid(ti))

		return -EIO;



	if (unlikely(bio_op(bio) == REQ_OP_DISCARD))

		return __send_discard(ci, ti);

	else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))

		return __send_write_same(ci, ti);

	else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))

		return __send_write_zeroes(ci, ti);



	if (bio_op(bio) == REQ_OP_ZONE_REPORT)

		len = ci->sector_count;

	else

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