Add a module option 'rd_logical_blksize' to allow the user to change
the logical sector size of the RAM disks.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/block/brd.c | 38 ++++++++++++++++++++++++++++++--------
1 file changed, 30 insertions(+), 8 deletions(-)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 2ebb5532a204..a9f3c6591e75 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -45,9 +45,11 @@ struct brd_device {
u64 brd_nr_folios;
unsigned int brd_sector_shift;
unsigned int brd_sector_size;
+ unsigned int brd_logical_sector_shift;
+ unsigned int brd_logical_sector_size;
};
-#define BRD_SECTOR_SHIFT(b) ((b)->brd_sector_shift - SECTOR_SHIFT)
+#define BRD_SECTOR_SHIFT(b) ((b)->brd_sector_shift - (b)->brd_logical_sector_shift)
static pgoff_t brd_sector_index(struct brd_device *brd, sector_t sector)
{
@@ -61,7 +63,7 @@ static int brd_sector_offset(struct brd_device *brd, sector_t sector)
{
unsigned int rd_sector_mask = (1 << BRD_SECTOR_SHIFT(brd)) - 1;
- return ((unsigned int)sector & rd_sector_mask) << SECTOR_SHIFT;
+ return ((unsigned int)sector & rd_sector_mask) << brd->brd_logical_sector_shift;
}
/*
@@ -152,7 +154,7 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n,
if (ret)
return ret;
if (copy < n) {
- sector += copy >> SECTOR_SHIFT;
+ sector += copy >> brd->brd_logical_sector_shift;
ret = brd_insert_folio(brd, sector, gfp);
}
return ret;
@@ -180,7 +182,7 @@ static void copy_to_brd(struct brd_device *brd, const void *src,
if (copy < n) {
src += copy;
- sector += copy >> SECTOR_SHIFT;
+ sector += copy >> brd->brd_logical_sector_shift;
copy = n - copy;
folio = brd_lookup_folio(brd, sector);
BUG_ON(!folio);
@@ -214,7 +216,7 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
if (copy < n) {
dst += copy;
- sector += copy >> SECTOR_SHIFT;
+ sector += copy >> brd->brd_logical_sector_shift;
copy = n - copy;
folio = brd_lookup_folio(brd, sector);
if (folio) {
@@ -273,8 +275,8 @@ static void brd_submit_bio(struct bio *bio)
int err;
/* Don't support un-aligned buffer */
- WARN_ON_ONCE((iter.offset & (SECTOR_SIZE - 1)) ||
- (len & (SECTOR_SIZE - 1)));
+ WARN_ON_ONCE((iter.offset & (brd->brd_logical_sector_size - 1)) ||
+ (len & (brd->brd_logical_sector_size - 1)));
err = brd_do_folio(brd, iter.folio, len, iter.offset,
bio->bi_opf, sector);
@@ -286,7 +288,7 @@ static void brd_submit_bio(struct bio *bio)
bio_io_error(bio);
return;
}
- sector += len >> SECTOR_SHIFT;
+ sector += len >> brd->brd_logical_sector_shift;
}
bio_endio(bio);
@@ -316,6 +318,10 @@ static unsigned int rd_blksize = PAGE_SIZE;
module_param(rd_blksize, uint, 0444);
MODULE_PARM_DESC(rd_blksize, "Blocksize of each RAM disk in bytes.");
+static unsigned int rd_logical_blksize = SECTOR_SIZE;
+module_param(rd_logical_blksize, uint, 0444);
+MODULE_PARM_DESC(rd_logical_blksize, "Logical blocksize of each RAM disk in bytes.");
+
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
MODULE_ALIAS("rd");
@@ -373,6 +379,21 @@ static int brd_alloc(int i)
}
brd->brd_sector_size = rd_blksize;
+ brd->brd_logical_sector_shift = ilog2(rd_logical_blksize);
+ if ((1ULL << brd->brd_sector_shift) != rd_blksize) {
+ pr_err("rd_logical_blksize %d is not supported\n",
+ rd_logical_blksize);
+ err = -EINVAL;
+ goto out_free_dev;
+ }
+ if (rd_logical_blksize > rd_blksize) {
+ pr_err("rd_logical_blksize %d larger than rd_blksize %d\n",
+ rd_logical_blksize, rd_blksize);
+ err = -EINVAL;
+ goto out_free_dev;
+ }
+ brd->brd_logical_sector_size = rd_logical_blksize;
+
xa_init(&brd->brd_folios);
snprintf(buf, DISK_NAME_LEN, "ram%d", i);
@@ -393,6 +414,7 @@ static int brd_alloc(int i)
set_capacity(disk, rd_size * 2);
blk_queue_physical_block_size(disk->queue, rd_blksize);
+ blk_queue_logical_block_size(disk->queue, rd_logical_blksize);
blk_queue_max_hw_sectors(disk->queue, 1ULL << (MAX_ORDER + PAGE_SECTORS_SHIFT));
/* Tell the block layer that this is not a rotational device */
--
2.35.3
