leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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

Browse Source 
__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>
This commit is contained in:
Mike Snitzer 2017-12-08 15:02:11 -05:00
parent 0776aa0e30
commit 3d7f45625a
1 changed files with 30 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
drivers/md/dm.c
View File

@ -1348,56 +1348,50 @@ static bool is_split_required_for_discard(struct dm_target *ti)
return ti->split_discard_bios; 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, get_num_bios_fn get_num_bios,
is_split_required_fn is_split_required) is_split_required_fn is_split_required)
{ {
struct dm_target *ti;
unsigned len; unsigned len;
unsigned num_bios; unsigned num_bios;
do { /*
ti = dm_table_find_target(ci->map, ci->sector); * Even though the device advertised support for this type of
if (!dm_target_is_valid(ti)) * request, that does not mean every target supports it, and
return -EIO; * 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))
* Even though the device advertised support for this type of len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
* request, that does not mean every target supports it, and else
* reconfiguration might also have changed that since the len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
* 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)) __send_duplicate_bios(ci, ti, num_bios, &len);
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); ci->sector += len;
ci->sector_count -= len;
ci->sector += len;
} while (ci->sector_count -= len);
return 0; 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); 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; unsigned len;
int r; 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); ti = dm_table_find_target(ci->map, ci->sector);
if (!dm_target_is_valid(ti)) if (!dm_target_is_valid(ti))
return -EIO; 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) if (bio_op(bio) == REQ_OP_ZONE_REPORT)
len = ci->sector_count; len = ci->sector_count;
else else