From: Mike Snitzer <snitzer@xxxxxxxxxx>
commit 666eed46769d929c3e13636134ecfc67d75ef548 upstream.
Commit 7dd76d1feec70 ("dm: improve bio splitting and associated IO
accounting") only called setup_split_accounting() from
__send_duplicate_bios() if a single bio were being issued. But the case
where duplicate bios are issued must call it too.
Otherwise the bio won't be split and resubmitted (via recursion through
block core back to DM) to submit the later portions of a bio (which may
map to an entirely different target).
For example, when discarding an entire DM striped device with the
following DM table:
vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048
Before (broken, discards the first striped target's devices twice):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:0, start=2049 len=22528
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=22528
After (works as expected):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:2, start=2048 len=22528
device-mapper: striped: target_stripe=1, bdev=7:3, start=2048 len=22528
Fixes: 7dd76d1feec70 ("dm: improve bio splitting and associated IO accounting")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Orange Kao <orange@xxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1522,6 +1522,8 @@ static int __send_duplicate_bios(struct
ret = 1;
break;
default:
+ if (len)
+ setup_split_accounting(ci, *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))) {
