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authorShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>2025-02-26 19:06:12 +0900
committerJens Axboe <axboe@kernel.dk>2025-03-03 11:17:52 -0700
commited0c31ae11732c177e9644b2026c32bfe2aa0f38 (patch)
tree2657b695f8517dab263cf11c8e26bb9e16049268 /drivers/block/null_blk
parent4f235000b1e88934d1e6117dc43ed814710ef4e2 (diff)
null_blk: pass transfer size to null_handle_rq()
As preparation to support partial data transfer, add a new argument to null_handle_rq() to pass the number of sectors to transfer. While at it, rename the function from null_handle_rq to null_handle_data_transfer. This commit does not change the behavior. Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20250226100613.1622564-5-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/null_blk')
-rw-r--r--drivers/block/null_blk/main.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 87037cb375c9..802576698812 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1263,25 +1263,37 @@ static int null_transfer(struct nullb *nullb, struct page *page,
return err;
}
-static blk_status_t null_handle_rq(struct nullb_cmd *cmd)
+/*
+ * Transfer data for the given request. The transfer size is capped with the
+ * nr_sectors argument.
+ */
+static blk_status_t null_handle_data_transfer(struct nullb_cmd *cmd,
+ sector_t nr_sectors)
{
struct request *rq = blk_mq_rq_from_pdu(cmd);
struct nullb *nullb = cmd->nq->dev->nullb;
int err = 0;
unsigned int len;
sector_t sector = blk_rq_pos(rq);
+ unsigned int max_bytes = nr_sectors << SECTOR_SHIFT;
+ unsigned int transferred_bytes = 0;
struct req_iterator iter;
struct bio_vec bvec;
spin_lock_irq(&nullb->lock);
rq_for_each_segment(bvec, rq, iter) {
len = bvec.bv_len;
+ if (transferred_bytes + len > max_bytes)
+ len = max_bytes - transferred_bytes;
err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,
op_is_write(req_op(rq)), sector,
rq->cmd_flags & REQ_FUA);
if (err)
break;
sector += len >> SECTOR_SHIFT;
+ transferred_bytes += len;
+ if (transferred_bytes >= max_bytes)
+ break;
}
spin_unlock_irq(&nullb->lock);
@@ -1333,7 +1345,7 @@ blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, enum req_op op,
if (op == REQ_OP_DISCARD)
return null_handle_discard(dev, sector, nr_sectors);
- return null_handle_rq(cmd);
+ return null_handle_data_transfer(cmd, nr_sectors);
}
static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd)