admin/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-12-07 20:06:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

null_blk: single kmap per bio segment

Browse Source 
Rather than kmap the the request bio segment for each sector, do
the mapping just once.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch
2025-11-05 17:54:46 -08:00
committed by Jens Axboe
parent 8459283819
commit 262a3dd04e
1 changed files with 14 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/block/null_blk/main.c
View File

@@ -1129,8 +1129,8 @@ again:
return 0;
}
static blk_status_t copy_to_nullb(struct nullb *nullb, struct page *source,
unsigned int off, sector_t sector, size_t n, bool is_fua)
static blk_status_t copy_to_nullb(struct nullb *nullb, void *source,
sector_t sector, size_t n, bool is_fua)
{
size_t temp, count = 0;
unsigned int offset;
@@ -1148,7 +1148,7 @@ static blk_status_t copy_to_nullb(struct nullb *nullb, struct page *source,
if (!t_page)
return BLK_STS_NOSPC;
memcpy_page(t_page->page, offset, source, off + count, temp);
memcpy_to_page(t_page->page, offset, source + count, temp);
__set_bit(sector & SECTOR_MASK, t_page->bitmap);
@@ -1161,8 +1161,8 @@ static blk_status_t copy_to_nullb(struct nullb *nullb, struct page *source,
return BLK_STS_OK;
}
static void copy_from_nullb(struct nullb *nullb, struct page *dest,
unsigned int off, sector_t sector, size_t n)
static void copy_from_nullb(struct nullb *nullb, void *dest, sector_t sector,
size_t n)
{
size_t temp, count = 0;
unsigned int offset;
@@ -1176,22 +1176,16 @@ static void copy_from_nullb(struct nullb *nullb, struct page *dest,
!null_cache_active(nullb));
if (t_page)
memcpy_page(dest, off + count, t_page->page, offset,
temp);
memcpy_from_page(dest + count, t_page->page, offset,
temp);
else
memzero_page(dest, off + count, temp);
memset(dest + count, 0, temp);
count += temp;
sector += temp >> SECTOR_SHIFT;
}
}
static void nullb_fill_pattern(struct nullb *nullb, struct page *page,
unsigned int len, unsigned int off)
{
memset_page(page, off, 0xff, len);
}
blk_status_t null_handle_discard(struct nullb_device *dev,
sector_t sector, sector_t nr_sectors)
{
@@ -1240,27 +1234,29 @@ static blk_status_t null_transfer(struct nullb *nullb, struct page *page,
struct nullb_device *dev = nullb->dev;
blk_status_t err = BLK_STS_OK;
unsigned int valid_len = len;
void *p;
p = kmap_local_page(page) + off;
if (!is_write) {
if (dev->zoned)
valid_len = null_zone_valid_read_len(nullb,
sector, len);
if (valid_len) {
copy_from_nullb(nullb, page, off, sector,
valid_len);
copy_from_nullb(nullb, p, sector, valid_len);
off += valid_len;
len -= valid_len;
}
if (len)
nullb_fill_pattern(nullb, page, len, off);
memset(p + valid_len, 0xff, len);
flush_dcache_page(page);
} else {
flush_dcache_page(page);
err = copy_to_nullb(nullb, page, off, sector, len, is_fua);
err = copy_to_nullb(nullb, p, sector, len, is_fua);
}
kunmap_local(p);
return err;
}