Implementation 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. Only request based queue mode will support for copy offload. Added tracefs support to copy IO tracing.
Reviewed-by: Hannes Reinecke <[email protected]> Suggested-by: Damien Le Moal <[email protected]> Signed-off-by: Anuj Gupta <[email protected]> Signed-off-by: Nitesh Shetty <[email protected]> Signed-off-by: Vincent Fu <[email protected]> --- Documentation/block/null_blk.rst | 5 ++ drivers/block/null_blk/main.c | 102 +++++++++++++++++++++++++++++- drivers/block/null_blk/null_blk.h | 1 + drivers/block/null_blk/trace.h | 23 +++++++ 4 files changed, 128 insertions(+), 3 deletions(-) diff --git a/Documentation/block/null_blk.rst b/Documentation/block/null_blk.rst index 4dd78f24d10a..6153e02fcf13 100644 --- a/Documentation/block/null_blk.rst +++ b/Documentation/block/null_blk.rst @@ -149,3 +149,8 @@ zone_size=[MB]: Default: 256 zone_nr_conv=[nr_conv]: Default: 0 The number of conventional zones to create when block device is zoned. If zone_nr_conv >= nr_zones, it will be reduced to nr_zones - 1. + +copy_max_bytes=[size in bytes]: Default: COPY_MAX_BYTES + A module and configfs parameter which can be used to set hardware/driver + supported maximum copy offload limit. + COPY_MAX_BYTES(=128MB at present) is defined in fs.h diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index b33b9ebfebd2..dcfbd5275414 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -172,6 +172,10 @@ 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 unsigned long g_copy_max_bytes = BLK_COPY_MAX_BYTES; +module_param_named(copy_max_bytes, g_copy_max_bytes, ulong, 0444); +MODULE_PARM_DESC(copy_max_bytes, "Maximum size of a copy command (in bytes)"); + static unsigned int nr_devices = 1; module_param(nr_devices, uint, 0444); MODULE_PARM_DESC(nr_devices, "Number of devices to register"); @@ -433,6 +437,7 @@ NULLB_DEVICE_ATTR(home_node, uint, NULL); NULLB_DEVICE_ATTR(queue_mode, uint, NULL); NULLB_DEVICE_ATTR(blocksize, uint, NULL); NULLB_DEVICE_ATTR(max_sectors, uint, NULL); +NULLB_DEVICE_ATTR(copy_max_bytes, uint, NULL); NULLB_DEVICE_ATTR(irqmode, uint, NULL); NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL); NULLB_DEVICE_ATTR(index, uint, NULL); @@ -577,6 +582,7 @@ static struct configfs_attribute *nullb_device_attrs[] = { &nullb_device_attr_queue_mode, &nullb_device_attr_blocksize, &nullb_device_attr_max_sectors, + &nullb_device_attr_copy_max_bytes, &nullb_device_attr_irqmode, &nullb_device_attr_hw_queue_depth, &nullb_device_attr_index, @@ -687,7 +693,7 @@ static ssize_t memb_group_features_show(struct config_item *item, char *page) "shared_tags,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,zone_append_max_sectors\n"); + "zone_size,zone_append_max_sectors,copy_max_bytes\n"); } CONFIGFS_ATTR_RO(memb_group_, features); @@ -753,6 +759,7 @@ static struct nullb_device *null_alloc_dev(void) dev->queue_mode = g_queue_mode; dev->blocksize = g_bs; dev->max_sectors = g_max_sectors; + dev->copy_max_bytes = g_copy_max_bytes; dev->irqmode = g_irqmode; dev->hw_queue_depth = g_hw_queue_depth; dev->blocking = g_blocking; @@ -1221,6 +1228,81 @@ static int null_transfer(struct nullb *nullb, struct page *page, return err; } +static inline int nullb_setup_copy(struct nullb *nullb, struct request *req, + bool is_fua) +{ + sector_t sector_in = 0, sector_out = 0; + loff_t offset_in, offset_out; + void *in, *out; + ssize_t chunk, rem = 0; + struct bio *bio; + struct nullb_page *t_page_in, *t_page_out; + u16 seg = 1; + int status = -EIO; + + if (blk_rq_nr_phys_segments(req) != BLK_COPY_MAX_SEGMENTS) + return status; + + /* + * First bio contains information about destination and last bio + * contains information about source. + */ + __rq_for_each_bio(bio, req) { + if (seg == blk_rq_nr_phys_segments(req)) { + sector_in = bio->bi_iter.bi_sector; + if (rem != bio->bi_iter.bi_size) + return status; + } else { + sector_out = bio->bi_iter.bi_sector; + rem = bio->bi_iter.bi_size; + } + seg++; + } + + trace_nullb_copy_op(req, sector_out << SECTOR_SHIFT, + sector_in << SECTOR_SHIFT, rem); + + spin_lock_irq(&nullb->lock); + while (rem > 0) { + chunk = min_t(size_t, nullb->dev->blocksize, rem); + offset_in = (sector_in & SECTOR_MASK) << SECTOR_SHIFT; + offset_out = (sector_out & SECTOR_MASK) << SECTOR_SHIFT; + + if (null_cache_active(nullb) && !is_fua) + null_make_cache_space(nullb, PAGE_SIZE); + + t_page_in = null_lookup_page(nullb, sector_in, false, + !null_cache_active(nullb)); + if (!t_page_in) + goto err; + t_page_out = null_insert_page(nullb, sector_out, + !null_cache_active(nullb) || + is_fua); + if (!t_page_out) + goto err; + + in = kmap_local_page(t_page_in->page); + out = kmap_local_page(t_page_out->page); + + memcpy(out + offset_out, in + offset_in, chunk); + kunmap_local(out); + kunmap_local(in); + __set_bit(sector_out & SECTOR_MASK, t_page_out->bitmap); + + if (is_fua) + null_free_sector(nullb, sector_out, true); + + rem -= chunk; + sector_in += chunk >> SECTOR_SHIFT; + sector_out += chunk >> SECTOR_SHIFT; + } + + status = 0; +err: + spin_unlock_irq(&nullb->lock); + return status; +} + static blk_status_t null_handle_rq(struct nullb_cmd *cmd) { struct request *rq = blk_mq_rq_from_pdu(cmd); @@ -1230,13 +1312,16 @@ static blk_status_t 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 (op_is_copy(req_op(rq))) + return nullb_setup_copy(nullb, rq, fua); 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) break; sector += len >> SECTOR_SHIFT; @@ -1721,6 +1806,12 @@ static void null_config_discard(struct nullb *nullb, struct queue_limits *lim) lim->max_hw_discard_sectors = UINT_MAX >> 9; } +static void null_config_copy(struct nullb *nullb, struct queue_limits *lim) +{ + lim->max_copy_hw_sectors = nullb->dev->copy_max_bytes >> SECTOR_SHIFT; + lim->max_copy_sectors = nullb->dev->copy_max_bytes >> SECTOR_SHIFT; +} + static const struct block_device_operations null_ops = { .owner = THIS_MODULE, .report_zones = null_report_zones, @@ -1843,6 +1934,9 @@ static int null_validate_conf(struct nullb_device *dev) return -EINVAL; } + if (dev->queue_mode == NULL_Q_BIO) + dev->copy_max_bytes = 0; + return 0; } @@ -1909,6 +2003,8 @@ static int null_add_dev(struct nullb_device *dev) if (dev->virt_boundary) lim.virt_boundary_mask = PAGE_SIZE - 1; null_config_discard(nullb, &lim); + null_config_copy(nullb, &lim); + if (dev->zoned) { rv = null_init_zoned_dev(dev, &lim); if (rv) diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h index 3234e6c85eed..c588729c17bd 100644 --- a/drivers/block/null_blk/null_blk.h +++ b/drivers/block/null_blk/null_blk.h @@ -91,6 +91,7 @@ struct nullb_device { unsigned int queue_mode; /* block interface */ unsigned int blocksize; /* block size */ unsigned int max_sectors; /* Max sectors per command */ + unsigned long copy_max_bytes; /* Max copy offload length in bytes */ unsigned int irqmode; /* IRQ completion handler */ unsigned int hw_queue_depth; /* queue depth */ unsigned int index; /* index of the disk, only valid with a disk */ diff --git a/drivers/block/null_blk/trace.h b/drivers/block/null_blk/trace.h index f9eadac6b22f..cda1a2249978 100644 --- a/drivers/block/null_blk/trace.h +++ b/drivers/block/null_blk/trace.h @@ -76,6 +76,29 @@ TRACE_EVENT(nullb_report_zones, ); #endif /* CONFIG_BLK_DEV_ZONED */ +TRACE_EVENT(nullb_copy_op, + TP_PROTO(struct request *req, + sector_t dst, sector_t src, size_t len), + TP_ARGS(req, dst, src, len), + TP_STRUCT__entry( + __array(char, disk, DISK_NAME_LEN) + __field(enum req_op, op) + __field(sector_t, dst) + __field(sector_t, src) + __field(size_t, len) + ), + TP_fast_assign( + __entry->op = req_op(req); + __assign_disk_name(__entry->disk, req->q->disk); + __entry->dst = dst; + __entry->src = src; + __entry->len = len; + ), + TP_printk("%s req=%-15s: dst=%llu, src=%llu, len=%lu", + __print_disk_name(__entry->disk), + blk_op_str(__entry->op), + __entry->dst, __entry->src, __entry->len) +); #endif /* _TRACE_NULLB_H */ #undef TRACE_INCLUDE_PATH -- 2.17.1
