On 4/11/23 01:10, Anuj Gupta wrote: > From: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> > > Implementaion is based on existing read and write infrastructure. > copy_max_bytes: A new configfs and module parameter is introduced, which > can be used to set hardware/driver supported maximum copy limit. > > Suggested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx> > Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> > Signed-off-by: Vincent Fu <vincent.fu@xxxxxxxxxxx> > --- > drivers/block/null_blk/main.c | 101 ++++++++++++++++++++++++++++++ > drivers/block/null_blk/null_blk.h | 8 +++ > 2 files changed, 109 insertions(+) > > diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c > index bc2c58724df3..e273e18ace74 100644 > --- a/drivers/block/null_blk/main.c > +++ b/drivers/block/null_blk/main.c > @@ -157,6 +157,10 @@ static int g_max_sectors; > module_param_named(max_sectors, g_max_sectors, int, 0444); > MODULE_PARM_DESC(max_sectors, "Maximum size of a command (in 512B sectors)"); > > +static int g_copy_max_bytes = COPY_MAX_BYTES; how about following ? matches nullb_device->copy_max_bytes type .. -static int g_copy_max_bytes = COPY_MAX_BYTES; -module_param_named(copy_max_bytes, g_copy_max_bytes, int, 0444); +static unsigned long g_copy_max_bytes = COPY_MAX_BYTES; +module_param_named(copy_max_bytes, g_copy_max_bytes, ulong, 0444); [...] > @@ -631,6 +637,7 @@ static ssize_t memb_group_features_show(struct config_item *item, char *page) > "badblocks,blocking,blocksize,cache_size," > "completion_nsec,discard,home_node,hw_queue_depth," > "irqmode,max_sectors,mbps,memory_backed,no_sched," > + "copy_max_bytes," > "poll_queues,power,queue_mode,shared_tag_bitmap,size," > "submit_queues,use_per_node_hctx,virt_boundary,zoned," > "zone_capacity,zone_max_active,zone_max_open," why not ? @@ -637,11 +637,12 @@ static ssize_t memb_group_features_show(struct config_item *item, char *page) "badblocks,blocking,blocksize,cache_size," "completion_nsec,discard,home_node,hw_queue_depth," "irqmode,max_sectors,mbps,memory_backed,no_sched," - "copy_max_bytes," "poll_queues,power,queue_mode,shared_tag_bitmap,size," "submit_queues,use_per_node_hctx,virt_boundary,zoned," "zone_capacity,zone_max_active,zone_max_open," - "zone_nr_conv,zone_offline,zone_readonly,zone_size\n"); + "zone_nr_conv,zone_offline,zone_readonly,zone_size" + "copy_max_bytes\n"); } [...] +static inline int nullb_setup_copy_read(struct nullb *nullb, + struct bio *bio) +{ + struct nullb_copy_token *token = bvec_kmap_local(&bio->bi_io_vec[0]); + + memcpy(token->subsys, "nullb", 5); do you really need to use memcpy here ? can token->subsys be a pointer and use with assignment token->subsys = nullb ? + token->sector_in = bio->bi_iter.bi_sector; + token->nullb = nullb; + token->sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; + + return 0; +} + no point in return 0 , use local bool for fua instead of repeating expression and no need to fold line for nullb_setup_copy_read() makes is easy to read and removes extra lines and indentation see below :- -static inline int nullb_setup_copy_read(struct nullb *nullb, - struct bio *bio) +static inline void nullb_setup_copy_read(struct nullb *nullb, struct bio *bio) { struct nullb_copy_token *token = bvec_kmap_local(&bio->bi_io_vec[0]); - memcpy(token->subsys, "nullb", 5); + token->subsys = "nullb; token->sector_in = bio->bi_iter.bi_sector; token->nullb = nullb; token->sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; - - return 0; } static inline int nullb_setup_copy_write(struct nullb *nullb, @@ -1334,20 +1331,21 @@ static int null_handle_rq(struct nullb_cmd *cmd) sector_t sector = blk_rq_pos(rq); struct req_iterator iter; struct bio_vec bvec; + bool fua = rq->cmd_flags & REQ_FUA; if (rq->cmd_flags & REQ_COPY) { if (op_is_write(req_op(rq))) - return nullb_setup_copy_write(nullb, rq->bio, - rq->cmd_flags & REQ_FUA); - return nullb_setup_copy_read(nullb, rq->bio); + return nullb_setup_copy_write(nullb, rq->bio, fua); + + nullb_setup_copy_read(nullb, rq->bio); + return 0; } spin_lock_irq(&nullb->lock); rq_for_each_segment(bvec, rq, iter) { len = bvec.bv_len; err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, - op_is_write(req_op(rq)), sector, - rq->cmd_flags & REQ_FUA); + op_is_write(req_op(rq)), sector, fua); if (err) { spin_unlock_irq(&nullb->lock); return err; @@ -1368,12 +1366,13 @@ static int null_handle_bio(struct nullb_cmd *cmd) sector_t sector = bio->bi_iter.bi_sector; struct bio_vec bvec; struct bvec_iter iter; + bool fua = bio->bi_opf & REQ_FUA if (bio->bi_opf & REQ_COPY) { if (op_is_write(bio_op(bio))) - return nullb_setup_copy_write(nullb, bio, - bio->bi_opf & REQ_FUA); - return nullb_setup_copy_read(nullb, bio); + return nullb_setup_copy_write(nullb, bio, fua); + nullb_setup_copy_read(nullb, bio); + return 0; } [...] +struct nullb_copy_token { + char subsys[5]; + struct nullb *nullb; + u64 sector_in; + u64 sectors; +}; + why not use sector_t ? diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h index c67c098d92fa..ffa4b6a6d19b 100644 --- a/drivers/block/null_blk/null_blk.h +++ b/drivers/block/null_blk/null_blk.h @@ -70,8 +70,8 @@ enum { struct nullb_copy_token { char subsys[5]; struct nullb *nullb; - u64 sector_in; - u64 sectors; + sector_t sector_in; + sector_t sectors; }; -ck