[PATCH 1/2] scsi: sd: enable sector size > PAGE_SIZE in scsi sd driver
From: sw . prabhu6
Date: Wed Feb 18 2026 - 23:39:50 EST
From: Swarna Prabhu <sw.prabhu6@xxxxxxxxx>
The WRITE SAME(16) and WRITE SAME(10) scsi commands uses
a page from a dedicated mempool('sd_page_pool') for its
payload. This pool was initialized to allocate single
pages, which was sufficient as long as the device sector
size did not exceed the PAGE_SIZE.
Given that block layer now supports block size upto
64K ie beyond PAGE_SIZE, initialize large page pool in
'sd_probe()' if a higher sector device is attached ensuring
atomicity. Adapt 'sd_set_special_bvec()' to use large page
pool when a higher sector size device is attached. Hence
enable sector sizes > PAGE_SIZE in scsi sd driver.
Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Signed-off-by: Swarna Prabhu <s.prabhu@xxxxxxxxxxx>
Co-developed-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
---
drivers/scsi/sd.c | 80 ++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 68 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d76996d6cbc9..ce09239c18cb 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -107,8 +107,11 @@ static void sd_config_write_same(struct scsi_disk *sdkp,
static void sd_revalidate_disk(struct gendisk *);
static DEFINE_IDA(sd_index_ida);
+static DEFINE_MUTEX(sd_mutex_lock);
static mempool_t *sd_page_pool;
+static mempool_t *sd_large_page_pool;
+static atomic_t sd_large_page_pool_users = ATOMIC_INIT(0);
static struct lock_class_key sd_bio_compl_lkclass;
static const char *sd_cache_types[] = {
@@ -116,6 +119,33 @@ static const char *sd_cache_types[] = {
"write back, no read (daft)"
};
+static int sd_large_pool_create(void)
+{
+ mutex_lock(&sd_mutex_lock);
+ if (!sd_large_page_pool) {
+ sd_large_page_pool = mempool_create_page_pool(
+ SD_MEMPOOL_SIZE, get_order(BLK_MAX_BLOCK_SIZE));
+ if (!sd_large_page_pool) {
+ printk(KERN_ERR "sd: can't create large page mempool\n");
+ mutex_unlock(&sd_mutex_lock);
+ return -ENOMEM;
+ }
+ }
+ atomic_inc(&sd_large_page_pool_users);
+ mutex_unlock(&sd_mutex_lock);
+ return 0;
+}
+
+static void sd_large_pool_destroy(void)
+{
+ mutex_lock(&sd_mutex_lock);
+ if (atomic_dec_and_test(&sd_large_page_pool_users)) {
+ mempool_destroy(sd_large_page_pool);
+ sd_large_page_pool = NULL;
+ }
+ mutex_unlock(&sd_mutex_lock);
+}
+
static void sd_disable_discard(struct scsi_disk *sdkp)
{
sdkp->provisioning_mode = SD_LBP_DISABLE;
@@ -928,14 +958,24 @@ static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd,
return protect;
}
-static void *sd_set_special_bvec(struct request *rq, unsigned int data_len)
+static void *sd_set_special_bvec(struct scsi_cmnd *cmd, unsigned int data_len)
{
struct page *page;
+ struct request *rq = scsi_cmd_to_rq(cmd);
+ struct scsi_device *sdp = cmd->device;
+ unsigned sector_size = sdp->sector_size;
+ unsigned int nr_pages = DIV_ROUND_UP(sector_size, PAGE_SIZE);
+ int n;
- page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
+ if (sector_size > PAGE_SIZE)
+ page = mempool_alloc(sd_large_page_pool, GFP_ATOMIC);
+ else
+ page = mempool_alloc(sd_page_pool, GFP_ATOMIC);
if (!page)
return NULL;
- clear_highpage(page);
+
+ for (n = 0; n < nr_pages; n++)
+ clear_highpage(page + n);
bvec_set_page(&rq->special_vec, page, data_len, 0);
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
return bvec_virt(&rq->special_vec);
@@ -951,7 +991,7 @@ static blk_status_t sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
unsigned int data_len = 24;
char *buf;
- buf = sd_set_special_bvec(rq, data_len);
+ buf = sd_set_special_bvec(cmd, data_len);
if (!buf)
return BLK_STS_RESOURCE;
@@ -1040,7 +1080,7 @@ static blk_status_t sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd,
u32 nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
u32 data_len = sdp->sector_size;
- if (!sd_set_special_bvec(rq, data_len))
+ if (!sd_set_special_bvec(cmd, data_len))
return BLK_STS_RESOURCE;
cmd->cmd_len = 16;
@@ -1067,7 +1107,7 @@ static blk_status_t sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd,
u32 nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
u32 data_len = sdp->sector_size;
- if (!sd_set_special_bvec(rq, data_len))
+ if (!sd_set_special_bvec(cmd, data_len))
return BLK_STS_RESOURCE;
cmd->cmd_len = 10;
@@ -1513,9 +1553,15 @@ static blk_status_t sd_init_command(struct scsi_cmnd *cmd)
static void sd_uninit_command(struct scsi_cmnd *SCpnt)
{
struct request *rq = scsi_cmd_to_rq(SCpnt);
+ struct scsi_device *sdp = SCpnt->device;
+ unsigned sector_size = sdp->sector_size;
- if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
- mempool_free(rq->special_vec.bv_page, sd_page_pool);
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) {
+ if (sector_size > PAGE_SIZE)
+ mempool_free(rq->special_vec.bv_page, sd_large_page_pool);
+ else
+ mempool_free(rq->special_vec.bv_page, sd_page_pool);
+ }
}
static bool sd_need_revalidate(struct gendisk *disk, struct scsi_disk *sdkp)
@@ -2912,10 +2958,7 @@ sd_read_capacity(struct scsi_disk *sdkp, struct queue_limits *lim,
"Sector size 0 reported, assuming 512.\n");
}
- if (sector_size != 512 &&
- sector_size != 1024 &&
- sector_size != 2048 &&
- sector_size != 4096) {
+ if (blk_validate_block_size(sector_size)) {
sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
sector_size);
/*
@@ -4043,6 +4086,12 @@ static int sd_probe(struct scsi_device *sdp)
sdkp->max_medium_access_timeouts = SD_MAX_MEDIUM_TIMEOUTS;
sd_revalidate_disk(gd);
+ if (sdp->sector_size > PAGE_SIZE) {
+ if (sd_large_pool_create()) {
+ error = -ENOMEM;
+ goto out_free_index;
+ }
+ }
if (sdp->removable) {
gd->flags |= GENHD_FL_REMOVABLE;
@@ -4060,6 +4109,8 @@ static int sd_probe(struct scsi_device *sdp)
if (error) {
device_unregister(&sdkp->disk_dev);
put_disk(gd);
+ if (sdp->sector_size > PAGE_SIZE)
+ sd_large_pool_destroy();
goto out;
}
@@ -4212,6 +4263,9 @@ static void sd_remove(struct scsi_device *sdp)
sd_shutdown(sdp);
put_disk(sdkp->disk);
+
+ if (sdp->sector_size > PAGE_SIZE)
+ sd_large_pool_destroy();
}
static inline bool sd_do_start_stop(struct scsi_device *sdev, bool runtime)
@@ -4435,6 +4489,8 @@ static void __exit exit_sd(void)
scsi_unregister_driver(&sd_template);
mempool_destroy(sd_page_pool);
+ if (sd_large_page_pool)
+ mempool_destroy(sd_large_page_pool);
class_unregister(&sd_disk_class);
--
2.39.5