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null_blk: return fixed zoned reads > write pointer

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A zoned block device maintains a write pointer within a zone, and reads
beyond the write pointer are undefined. Fill data buffer returned above
the write pointer with 0xFF.

Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ajay Joshi 2019-10-17 14:19:43 -07:00 committed by Jens Axboe
parent 45919fbfe1
commit dd85b4922d
3 changed files with 52 additions and 3 deletions
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8
drivers/block/null_blk.h
View File

@ -96,6 +96,8 @@ int null_zone_report(struct gendisk *disk, sector_t sector,
blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
enum req_opf op, sector_t sector,
sector_t nr_sectors);
size_t null_zone_valid_read_len(struct nullb *nullb,
sector_t sector, unsigned int len);
#else
static inline int null_zone_init(struct nullb_device *dev)
{
@ -115,5 +117,11 @@ static inline blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
{
return BLK_STS_NOTSUPP;
}
static inline size_t null_zone_valid_read_len(struct nullb *nullb,
sector_t sector,
unsigned int len)
{
return len;
}
#endif /* CONFIG_BLK_DEV_ZONED */
#endif /* __NULL_BLK_H */

26
drivers/block/null_blk_main.c
View File

@ -1022,6 +1022,16 @@ next:
return 0;
}
static void nullb_fill_pattern(struct nullb *nullb, struct page *page,
unsigned int len, unsigned int off)
{
void *dst;
dst = kmap_atomic(page);
memset(dst + off, 0xFF, len);
kunmap_atomic(dst);
}
static void null_handle_discard(struct nullb *nullb, sector_t sector, size_t n)
{
size_t temp;
@ -1062,10 +1072,24 @@ static int null_transfer(struct nullb *nullb, struct page *page,
unsigned int len, unsigned int off, bool is_write, sector_t sector,
bool is_fua)
{
struct nullb_device *dev = nullb->dev;
unsigned int valid_len = len;
int err = 0;
if (!is_write) {
err = copy_from_nullb(nullb, page, off, sector, len);
if (dev->zoned)
valid_len = null_zone_valid_read_len(nullb,
sector, len);
if (valid_len) {
err = copy_from_nullb(nullb, page, off,
sector, valid_len);
off += valid_len;
len -= valid_len;
}
if (len)
nullb_fill_pattern(nullb, page, len, off);
flush_dcache_page(page);
} else {
flush_dcache_page(page);

21
drivers/block/null_blk_zoned.c
View File

@ -84,6 +84,24 @@ int null_zone_report(struct gendisk *disk, sector_t sector,
return 0;
}
size_t null_zone_valid_read_len(struct nullb *nullb,
sector_t sector, unsigned int len)
{
struct nullb_device *dev = nullb->dev;
struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
unsigned int nr_sectors = len >> SECTOR_SHIFT;
/* Read must be below the write pointer position */
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
sector + nr_sectors <= zone->wp)
return len;
if (sector > zone->wp)
return 0;
return (zone->wp - sector) << SECTOR_SHIFT;
}
static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
unsigned int nr_sectors)
{
@ -121,8 +139,7 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
{
struct nullb_device *dev = cmd->nq->dev;
unsigned int zno = null_zone_no(dev, sector);
struct blk_zone *zone = &dev->zones[zno];
struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
size_t i;
switch (req_op(cmd->rq)) {