From 3d7f45625a84696f61c6470a887bdc65180937a9 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Fri, 8 Dec 2017 15:02:11 -0500
Subject: [PATCH] dm: fix __send_changing_extent_only() to send first bio and
chain remainder
Git-commit: 3d7f45625a84696f61c6470a887bdc65180937a9
Patch-mainline: v4.16-rc1
References: bsc#1093023
__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: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm.c | 66 ++++++++++++++++++++++++++-------------------------------
1 file changed, 30 insertions(+), 36 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 9d255e5c9688..4e7682afebfa 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1348,56 +1348,50 @@ 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
- * reconfiguration might also have changed that since the
- * check was performed.
- */
- num_bios = get_num_bios ? get_num_bios(ti) : 0;
- if (!num_bios)
- return -EOPNOTSUPP;
+ /*
+ * Even though the device advertised support for this type of
+ * request, that does not mean every target supports it, and
+ * reconfiguration might also have changed that since the
+ * check was performed.
+ */
+ num_bios = get_num_bios ? get_num_bios(ti) : 0;
+ if (!num_bios)
+ return -EOPNOTSUPP;
- if (is_split_required && !is_split_required(ti))
- len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
- else
- len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
+ if (is_split_required && !is_split_required(ti))
+ len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
+ else
+ len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
- __send_duplicate_bios(ci, ti, num_bios, &len);
+ __send_duplicate_bios(ci, ti, num_bios, &len);
- ci->sector += len;
- } while (ci->sector_count -= len);
+ ci->sector += 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
--
2.16.3