From: Nitesh Shetty <nj.she...@samsung.com>
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.lem...@opensource.wdc.com>
Signed-off-by: Anuj Gupta <anuj2...@samsung.com>
Signed-off-by: Nitesh Shetty <nj.she...@samsung.com>
Signed-off-by: Vincent Fu <vincent...@samsung.com>
---
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;
+module_param_named(copy_max_bytes, g_copy_max_bytes, int, 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");
@@ -409,6 +413,7 @@ 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);
@@ -550,6 +555,7 @@ 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,
@@ -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,"
@@ -693,6 +700,7 @@ 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;
@@ -1242,6 +1250,81 @@ static int null_transfer(struct nullb *nullb, struct
page *page,
return err;
}
+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);
+ 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,
+ struct bio *bio, bool is_fua)
+{
+ struct nullb_copy_token *token = bvec_kmap_local(&bio->bi_io_vec[0]);
+ sector_t sector_in, sector_out;
+ void *in, *out;
+ size_t rem, temp;
+ unsigned long offset_in, offset_out;
+ struct nullb_page *t_page_in, *t_page_out;
+ int ret = -EIO;
+
+ if (unlikely(memcmp(token->subsys, "nullb", 5)))
+ return -EINVAL;
+ if (unlikely(token->nullb != nullb))
+ return -EINVAL;
+ if (WARN_ON(token->sectors != bio->bi_iter.bi_size >> SECTOR_SHIFT))
+ return -EINVAL;
+
+ sector_in = token->sector_in;
+ sector_out = bio->bi_iter.bi_sector;
+ rem = token->sectors << SECTOR_SHIFT;
+
+ spin_lock_irq(&nullb->lock);
+ while (rem > 0) {
+ temp = 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, temp);
+ 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 -= temp;
+ sector_in += temp >> SECTOR_SHIFT;
+ sector_out += temp >> SECTOR_SHIFT;
+ }
+
+ ret = 0;
+err:
+ spin_unlock_irq(&nullb->lock);
+ return ret;
+}
+
static int null_handle_rq(struct nullb_cmd *cmd)
{
struct request *rq = cmd->rq;
@@ -1252,6 +1335,13 @@ static int null_handle_rq(struct nullb_cmd *cmd)
struct req_iterator iter;
struct bio_vec bvec;
+ 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);
+ }
+
spin_lock_irq(&nullb->lock);
rq_for_each_segment(bvec, rq, iter) {
len = bvec.bv_len;
@@ -1279,6 +1369,13 @@ static int null_handle_bio(struct nullb_cmd *cmd)
struct bio_vec bvec;
struct bvec_iter iter;
+ 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);
+ }
+
spin_lock_irq(&nullb->lock);
bio_for_each_segment(bvec, bio, iter) {
len = bvec.bv_len;
@@ -2109,6 +2206,10 @@ static int null_add_dev(struct nullb_device *dev)
dev->max_sectors = queue_max_hw_sectors(nullb->q);
dev->max_sectors = min(dev->max_sectors, BLK_DEF_MAX_SECTORS);
blk_queue_max_hw_sectors(nullb->q, dev->max_sectors);
+ blk_queue_max_copy_sectors_hw(nullb->q,
+ dev->copy_max_bytes >> SECTOR_SHIFT);
+ if (dev->copy_max_bytes)
+ blk_queue_flag_set(QUEUE_FLAG_COPY, nullb->disk->queue);
if (dev->virt_boundary)
blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1);
diff --git a/drivers/block/null_blk/null_blk.h
b/drivers/block/null_blk/null_blk.h
index eb5972c50be8..c67c098d92fa 100644
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -67,6 +67,13 @@ enum {
NULL_Q_MQ = 2,
};
+struct nullb_copy_token {
+ char subsys[5];
+ struct nullb *nullb;
+ u64 sector_in;
+ u64 sectors;
+};
+
struct nullb_device {
struct nullb *nullb;
struct config_item item;
@@ -102,6 +109,7 @@ 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 */
--
2.35.1.500.gb896f729e2
--
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