bio-integrity: Fix bio_integrity_verify segment start bug

This patch addresses a bug in bio_integrity_verify() code that has
been causing DIF READ verify operations to be silently skipped.

The issue is that bio->bi_idx will have been incremented within
bio_advance() code in the normal blk_update_request() ->
req_bio_endio() completion path, and bio_integrity_verify() is
using bio_for_each_segment() which starts the bio segment walk
at the current bio->bi_idx.

So instead use bio_for_each_segment_all() to always start the bio
segment walk from zero, regardless of the current bio->bi_idx
value after bio_advance() has been called.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: stable@kernel.dk # >= v3.10
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Nicholas Bellinger 2014-01-21 20:32:05 -08:00 committed by Jens Axboe
parent bca266b388
commit 5837c80e87

View File

@ -447,20 +447,21 @@ static int bio_integrity_verify(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_exchg bix;
struct bio_vec bv;
struct bvec_iter iter;
struct bio_vec *bv;
sector_t sector = bio->bi_integrity->bip_iter.bi_sector;
unsigned int sectors, total, ret;
void *prot_buf = bio->bi_integrity->bip_buf;
int i;
ret = total = 0;
bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
bix.sector_size = bi->sector_size;
bio_for_each_segment(bv, bio, iter) {
void *kaddr = kmap_atomic(bv.bv_page);
bix.data_buf = kaddr + bv.bv_offset;
bix.data_size = bv.bv_len;
bio_for_each_segment_all(bv, bio, i) {
void *kaddr = kmap_atomic(bv->bv_page);
bix.data_buf = kaddr + bv->bv_offset;
bix.data_size = bv->bv_len;
bix.prot_buf = prot_buf;
bix.sector = sector;
@ -471,7 +472,7 @@ static int bio_integrity_verify(struct bio *bio)
return ret;
}
sectors = bv.bv_len / bi->sector_size;
sectors = bv->bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;