On 3/27/23 17:40, Anuj Gupta wrote: > From: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> > Drop the period at the end of the patch title. > Before enabling copy for dm target, check if underlying devices and > dm target support copy. Avoid split happening inside dm target. > Fail early if the request needs split, currently splitting copy > request is not supported. > > Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> > --- > drivers/md/dm-table.c | 42 +++++++++++++++++++++++++++++++++++ > drivers/md/dm.c | 7 ++++++ > include/linux/device-mapper.h | 5 +++++ > 3 files changed, 54 insertions(+) > > diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c > index 7899f5fb4c13..45e894b9e3be 100644 > --- a/drivers/md/dm-table.c > +++ b/drivers/md/dm-table.c > @@ -1863,6 +1863,39 @@ static bool dm_table_supports_nowait(struct dm_table *t) > return true; > } > > +static int device_not_copy_capable(struct dm_target *ti, struct dm_dev *dev, > + sector_t start, sector_t len, void *data) > +{ > + struct request_queue *q = bdev_get_queue(dev->bdev); > + > + return !blk_queue_copy(q); > +} > + > +static bool dm_table_supports_copy(struct dm_table *t) > +{ > + struct dm_target *ti; > + unsigned int i; > + > + for (i = 0; i < t->num_targets; i++) { > + ti = dm_table_get_target(t, i); > + > + if (!ti->copy_offload_supported) > + return false; > + > + /* > + * target provides copy support (as implied by setting > + * 'copy_offload_supported') > + * and it relies on _all_ data devices having copy support. > + */ > + if (!ti->type->iterate_devices || > + ti->type->iterate_devices(ti, > + device_not_copy_capable, NULL)) > + return false; > + } > + > + return true; > +} > + > static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev, > sector_t start, sector_t len, void *data) > { > @@ -1945,6 +1978,15 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, > q->limits.discard_misaligned = 0; > } > > + if (!dm_table_supports_copy(t)) { > + blk_queue_flag_clear(QUEUE_FLAG_COPY, q); > + /* Must also clear copy limits... */ Not a useful comment. The code is clear. > + q->limits.max_copy_sectors = 0; > + q->limits.max_copy_sectors_hw = 0; > + } else { > + blk_queue_flag_set(QUEUE_FLAG_COPY, q); > + } > + > if (!dm_table_supports_secure_erase(t)) > q->limits.max_secure_erase_sectors = 0; > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > index 2d0f934ba6e6..08ec51000af8 100644 > --- a/drivers/md/dm.c > +++ b/drivers/md/dm.c > @@ -1693,6 +1693,13 @@ static blk_status_t __split_and_process_bio(struct clone_info *ci) > if (unlikely(ci->is_abnormal_io)) > return __process_abnormal_io(ci, ti); > > + if ((unlikely(op_is_copy(ci->bio->bi_opf)) && > + max_io_len(ti, ci->sector) < ci->sector_count)) { > + DMERR("Error, IO size(%u) > max target size(%llu)\n", > + ci->sector_count, max_io_len(ti, ci->sector)); > + return BLK_STS_IOERR; > + } > + > /* > * Only support bio polling for normal IO, and the target io is > * exactly inside the dm_io instance (verified in dm_poll_dm_io) > diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h > index 7975483816e4..44969a20295e 100644 > --- a/include/linux/device-mapper.h > +++ b/include/linux/device-mapper.h > @@ -380,6 +380,11 @@ struct dm_target { > * bio_set_dev(). NOTE: ideally a target should _not_ need this. > */ > bool needs_bio_set_dev:1; > + > + /* > + * copy offload is supported > + */ > + bool copy_offload_supported:1; > }; > > void *dm_per_bio_data(struct bio *bio, size_t data_size); -- Damien Le Moal Western Digital Research