Re: [PATCH 1/2] scsi: fix write_same16 and write_same10 for sector size > PAGE_SIZE

From: Bart Van Assche
Date: Tue Dec 02 2025 - 19:29:05 EST


On 12/1/25 4:15 PM, sw.prabhu6@xxxxxxxxx wrote:
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0252d3f6bed1..c3502fcba1bb 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -895,11 +895,20 @@ static void sd_config_discard(struct scsi_disk *sdkp, struct queue_limits *lim,
static void *sd_set_special_bvec(struct request *rq, unsigned int data_len)
{
struct page *page;
+ struct scsi_device *sdp = scsi_disk(rq->q->disk)->device;
+ unsigned sector_size = sdp->sector_size;
+ unsigned int nr_pages = DIV_ROUND_UP(sector_size, PAGE_SIZE);
+ int n = 0;
page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
if (!page)
return NULL;
- clear_highpage(page);
+
+ do {
+ clear_highpage(page + n);
+ n++;
+ } while (n < nr_pages);
+
bvec_set_page(&rq->special_vec, page, data_len, 0);
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
return bvec_virt(&rq->special_vec);
@@ -4368,7 +4377,7 @@ static int __init init_sd(void)
if (err)
goto err_out;
- sd_page_pool = mempool_create_page_pool(SD_MEMPOOL_SIZE, 0);
+ sd_page_pool = mempool_create_page_pool(SD_MEMPOOL_SIZE, get_order(BLK_MAX_BLOCK_SIZE));
if (!sd_page_pool) {
printk(KERN_ERR "sd: can't init discard page pool\n");
err = -ENOMEM;

Have the above changes been tested? I don't see any changes for this
code from drivers/scsi/sd.c:

if (sector_size != 512 &&
sector_size != 1024 &&
sector_size != 2048 &&
sector_size != 4096) {
sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
sector_size);
[ ... ]
}

Thanks,

Bart.