Commit 3451cf34 authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

null_blk: allow byte aligned memory offsets 



Allowing byte aligned memory provides a nice testing ground for
direct-io.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Tested-by: default avatarHans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 262a3dd0

drivers/block/null_blk/main.c

+24 −21
Original line number Diff line number Diff line
@@ -1130,25 +1130,27 @@ static int null_make_cache_space(struct nullb *nullb, unsigned long n) 
}



static blk_status_t copy_to_nullb(struct nullb *nullb, void *source,

				  sector_t sector, size_t n, bool is_fua)

				  loff_t pos, size_t n, bool is_fua)

{

	size_t temp, count = 0;

	unsigned int offset;

	struct nullb_page *t_page;

	sector_t sector;



	while (count < n) {

		temp = min_t(size_t, nullb->dev->blocksize, n - count);

		temp = min3(nullb->dev->blocksize, n - count,

			    PAGE_SIZE - offset_in_page(pos));

		sector = pos >> SECTOR_SHIFT;



		if (null_cache_active(nullb) && !is_fua)

			null_make_cache_space(nullb, PAGE_SIZE);



		offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;

		t_page = null_insert_page(nullb, sector,

			!null_cache_active(nullb) || is_fua);

		if (!t_page)

			return BLK_STS_NOSPC;



		memcpy_to_page(t_page->page, offset, source + count, temp);

		memcpy_to_page(t_page->page, offset_in_page(pos),

			       source + count, temp);



		__set_bit(sector & SECTOR_MASK, t_page->bitmap);
@@ -1156,33 +1158,33 @@ static blk_status_t copy_to_nullb(struct nullb *nullb, void *source, 
			null_free_sector(nullb, sector, true);



		count += temp;

		sector += temp >> SECTOR_SHIFT;

		pos += temp;

	}

	return BLK_STS_OK;

}



static void copy_from_nullb(struct nullb *nullb, void *dest, sector_t sector,

static void copy_from_nullb(struct nullb *nullb, void *dest, loff_t pos,

			    size_t n)

{

	size_t temp, count = 0;

	unsigned int offset;

	struct nullb_page *t_page;

	sector_t sector;



	while (count < n) {

		temp = min_t(size_t, nullb->dev->blocksize, n - count);

		temp = min3(nullb->dev->blocksize, n - count,

			    PAGE_SIZE - offset_in_page(pos));

		sector = pos >> SECTOR_SHIFT;



		offset = (sector & SECTOR_MASK) << SECTOR_SHIFT;

		t_page = null_lookup_page(nullb, sector, false,

			!null_cache_active(nullb));



		if (t_page)

			memcpy_from_page(dest + count, t_page->page, offset,

					 temp);

			memcpy_from_page(dest + count, t_page->page,

					 offset_in_page(pos), temp);

		else

			memset(dest + count, 0, temp);



		count += temp;

		sector += temp >> SECTOR_SHIFT;

		pos += temp;

	}

}
@@ -1228,7 +1230,7 @@ static blk_status_t null_handle_flush(struct nullb *nullb) 
}



static blk_status_t null_transfer(struct nullb *nullb, struct page *page,

	unsigned int len, unsigned int off, bool is_write, sector_t sector,

	unsigned int len, unsigned int off, bool is_write, loff_t pos,

	bool is_fua)

{

	struct nullb_device *dev = nullb->dev;
@@ -1240,10 +1242,10 @@ static blk_status_t null_transfer(struct nullb *nullb, struct page *page, 
	if (!is_write) {

		if (dev->zoned)

			valid_len = null_zone_valid_read_len(nullb,

				sector, len);

				pos >> SECTOR_SHIFT, len);



		if (valid_len) {

			copy_from_nullb(nullb, p, sector, valid_len);

			copy_from_nullb(nullb, p, pos, valid_len);

			off += valid_len;

			len -= valid_len;

		}
@@ -1253,7 +1255,7 @@ static blk_status_t null_transfer(struct nullb *nullb, struct page *page, 
		flush_dcache_page(page);

	} else {

		flush_dcache_page(page);

		err = copy_to_nullb(nullb, p, sector, len, is_fua);

		err = copy_to_nullb(nullb, p, pos, len, is_fua);

	}



	kunmap_local(p);
@@ -1271,7 +1273,7 @@ static blk_status_t null_handle_data_transfer(struct nullb_cmd *cmd, 
	struct nullb *nullb = cmd->nq->dev->nullb;

	blk_status_t err = BLK_STS_OK;

	unsigned int len;

	sector_t sector = blk_rq_pos(rq);

	loff_t pos = blk_rq_pos(rq) << SECTOR_SHIFT;

	unsigned int max_bytes = nr_sectors << SECTOR_SHIFT;

	unsigned int transferred_bytes = 0;

	struct req_iterator iter;
@@ -1283,11 +1285,11 @@ static blk_status_t null_handle_data_transfer(struct nullb_cmd *cmd, 
		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,

				     op_is_write(req_op(rq)), pos,

				     rq->cmd_flags & REQ_FUA);

		if (err)

			break;

		sector += len >> SECTOR_SHIFT;

		pos += len;

		transferred_bytes += len;

		if (transferred_bytes >= max_bytes)

			break;
@@ -1944,6 +1946,7 @@ static int null_add_dev(struct nullb_device *dev) 
		.logical_block_size	= dev->blocksize,

		.physical_block_size	= dev->blocksize,

		.max_hw_sectors		= dev->max_sectors,

		.dma_alignment		= 1,

	};



	struct nullb *nullb;

drivers/block/null_blk/zoned.c

+1 −1
Original line number Diff line number Diff line
@@ -242,7 +242,7 @@ size_t null_zone_valid_read_len(struct nullb *nullb, 
{

	struct nullb_device *dev = nullb->dev;

	struct nullb_zone *zone = &dev->zones[null_zone_no(dev, sector)];

	unsigned int nr_sectors = len >> SECTOR_SHIFT;

	unsigned int nr_sectors = DIV_ROUND_UP(len, SECTOR_SHIFT);



	/* Read must be below the write pointer position */

	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||