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authorMike Snitzer <snitzer@kernel.org>2022-04-14 18:52:54 +0300
committerMike Snitzer <snitzer@kernel.org>2022-04-15 03:01:54 +0300
commit7dd06a2548b2bf516ef2e79873a9cdd00b354b99 (patch)
tree1383e1cbfb0755d97b8fabca747438d374f5b03a
parent73d7b06e902dd294e1f61554f7c403d0f705cf92 (diff)
downloadlinux-7dd06a2548b2bf516ef2e79873a9cdd00b354b99.tar.xz
dm: allow dm_accept_partial_bio() for dm_io without duplicate bios
The intent behind commit e6fc9f62ce6e ("dm: flag clones created by __send_duplicate_bios") was to formally disallow the use of dm_accept_partial_bio() where it simply isn't possible -- due to constraint that multiple bios cannot meaningfully update a shared tio->len_ptr. But that commit went too far and disallowed the case where "abormal" IO (e.g. WRITE_ZEROES) is only using a single bio. Fix this by not marking a dm_io with a single dm_target_io (and bio), that happens to be created by __send_duplicate_bios, as DM_TIO_IS_DUPLICATE_BIO. Also remove 'unsigned *len' parameter from alloc_multiple_bios(). This commit fixes a dm_accept_partial_bio() BUG_ON() with dm-zoned when a WRITE_ZEROES bio is issued. Fixes: 655f3aad7aa4 ("dm: switch dm_target_io booleans over to proper flags") Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
-rw-r--r--drivers/md/dm.c17
1 files changed, 6 insertions, 11 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 3c5fad7c4ee6..fc1f9583a271 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1323,8 +1323,7 @@ static void __map_bio(struct bio *clone)
}
static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
- struct dm_target *ti, unsigned num_bios,
- unsigned *len)
+ struct dm_target *ti, unsigned num_bios)
{
struct bio *bio;
int try;
@@ -1335,7 +1334,7 @@ static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
if (try)
mutex_lock(&ci->io->md->table_devices_lock);
for (bio_nr = 0; bio_nr < num_bios; bio_nr++) {
- bio = alloc_tio(ci, ti, bio_nr, len,
+ bio = alloc_tio(ci, ti, bio_nr, NULL,
try ? GFP_NOIO : GFP_NOWAIT);
if (!bio)
break;
@@ -1363,11 +1362,11 @@ static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
break;
case 1:
clone = alloc_tio(ci, ti, 0, len, GFP_NOIO);
- dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
__map_bio(clone);
break;
default:
- alloc_multiple_bios(&blist, ci, ti, num_bios, len);
+ /* dm_accept_partial_bio() is not supported with shared tio->len_ptr */
+ alloc_multiple_bios(&blist, ci, ti, num_bios);
while ((clone = bio_list_pop(&blist))) {
dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
__map_bio(clone);
@@ -1407,14 +1406,10 @@ static void __send_changing_extent_only(struct clone_info *ci, struct dm_target
len = min_t(sector_t, ci->sector_count,
max_io_len_target_boundary(ti, dm_target_offset(ti, ci->sector)));
- /*
- * dm_accept_partial_bio cannot be used with duplicate bios,
- * so update clone_info cursor before __send_duplicate_bios().
- */
+ __send_duplicate_bios(ci, ti, num_bios, &len);
+
ci->sector += len;
ci->sector_count -= len;
-
- __send_duplicate_bios(ci, ti, num_bios, &len);
}
static bool is_abnormal_io(struct bio *bio)