From: Mike Snitzer snitzer@kernel.org
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@vger.kernel.org Reported-by: Orange Kao orange@aiven.io Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1509,6 +1509,8 @@ 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))) {