This is one prep patch for supporting iopoll for dm device. The direct IO routine will set REQ_NOWAIT flag for REQ_HIPRI IO (that is, IO will do iopoll) in bio_set_polled(). Then in the IO submission routine, the ability of handling REQ_NOWAIT of the block device will be checked for REQ_HIPRI IO in submit_bio_checks(). -EOPNOTSUPP will be returned if the block device doesn't support REQ_NOWAIT. DM lacks support for REQ_NOWAIT until commit 6abc49468eea ("dm: add support for REQ_NOWAIT and enable it for linear target"). Since then, dm targets that support REQ_NOWAIT should advertise DM_TARGET_NOWAIT feature. This patch adds support for DM_TARGET_NOWAIT for those dm targets, the .map() algorithm of which just involves sector recalculation. Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx> --- Hi Mike, I could split these boilerplate code that each dm target have one seperate patch if you think that would be better. --- drivers/md/dm-stripe.c | 2 +- drivers/md/dm-switch.c | 1 + drivers/md/dm-unstripe.c | 1 + drivers/md/dm-zero.c | 1 + 4 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 151d022b032d..df359d33cda8 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -496,7 +496,7 @@ static void stripe_io_hints(struct dm_target *ti, static struct target_type stripe_target = { .name = "striped", .version = {1, 6, 0}, - .features = DM_TARGET_PASSES_INTEGRITY, + .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT, .module = THIS_MODULE, .ctr = stripe_ctr, .dtr = stripe_dtr, diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c index bff4c7fa1cd2..262e2b0fd975 100644 --- a/drivers/md/dm-switch.c +++ b/drivers/md/dm-switch.c @@ -550,6 +550,7 @@ static int switch_iterate_devices(struct dm_target *ti, static struct target_type switch_target = { .name = "switch", .version = {1, 1, 0}, + .features = DM_TARGET_NOWAIT, .module = THIS_MODULE, .ctr = switch_ctr, .dtr = switch_dtr, diff --git a/drivers/md/dm-unstripe.c b/drivers/md/dm-unstripe.c index e673dacf6418..7357c1bd5863 100644 --- a/drivers/md/dm-unstripe.c +++ b/drivers/md/dm-unstripe.c @@ -178,6 +178,7 @@ static void unstripe_io_hints(struct dm_target *ti, static struct target_type unstripe_target = { .name = "unstriped", .version = {1, 1, 0}, + .features = DM_TARGET_NOWAIT, .module = THIS_MODULE, .ctr = unstripe_ctr, .dtr = unstripe_dtr, diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c index b65ca8dcfbdc..faa1dbffc8b4 100644 --- a/drivers/md/dm-zero.c +++ b/drivers/md/dm-zero.c @@ -59,6 +59,7 @@ static int zero_map(struct dm_target *ti, struct bio *bio) static struct target_type zero_target = { .name = "zero", .version = {1, 1, 0}, + .features = DM_TARGET_NOWAIT, .module = THIS_MODULE, .ctr = zero_ctr, .map = zero_map, -- 2.27.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel