/**
* bio_integrity_process - Process integrity metadata for a bio
* @bio: bio to generate/verify integrity metadata for
* @proc_fn: Pointer to the relevant processing function
*/
static int bio_integrity_process(struct bio *bio,
integrity_processing_fn *proc_fn)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_iter iter;
struct bvec_iter bviter;
struct bio_vec bv;
struct bio_integrity_payload *bip = bio_integrity(bio);
unsigned int ret = 0;
void *prot_buf = page_address(bip->bip_vec->bv_page) +
bip->bip_vec->bv_offset;
iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
iter.interval = bi->interval;
iter.seed = bip_get_seed(bip);
iter.prot_buf = prot_buf;
bio_for_each_segment(bv, bio, bviter) {
void *kaddr = kmap_atomic(bv.bv_page);
iter.data_buf = kaddr + bv.bv_offset;
iter.data_size = bv.bv_len;
ret = proc_fn(&iter);
if (ret) {
kunmap_atomic(kaddr);
return ret;
}
kunmap_atomic(kaddr);
}
/**
* bio_integrity_generate - Generate integrity metadata for a bio
* @bio: bio to generate integrity metadata for
*
* Description: Generates integrity metadata for a bio by calling the
* block device's generation callback function. The bio must have a
* bip attached with enough room to accommodate the generated
* integrity metadata.
*/
static void bio_integrity_generate(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;
sector_t sector = bio->bi_iter.bi_sector;
unsigned int sectors, total;
void *prot_buf = bio->bi_integrity->bip_buf;
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;
bix.prot_buf = prot_buf;
bix.sector = sector;
bi->generate_fn(&bix);
sectors = bv.bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;
BUG_ON(total > bio->bi_integrity->bip_iter.bi_size);
kunmap_atomic(kaddr);
}
static int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len,
int set)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip->bip_buf == NULL);
if (bi->tag_size == 0)
return -1;
nr_sectors = bio_integrity_hw_sectors(bi,
DIV_ROUND_UP(len, bi->tag_size));
if (nr_sectors * bi->tuple_size > bip->bip_iter.bi_size) {
printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__,
nr_sectors * bi->tuple_size, bip->bip_iter.bi_size);
return -1;
}
if (set)
bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
else
bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
return 0;
}
/**
* bio_integrity_tag_size - Retrieve integrity tag space
* @bio: bio to inspect
*
* Description: Returns the maximum number of tag bytes that can be
* attached to this bio. Filesystems can use this to determine how
* much metadata to attach to an I/O.
*/
unsigned int bio_integrity_tag_size(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
BUG_ON(bio->bi_iter.bi_size == 0);
return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size);
}
static int bdev_integrity_enabled(struct block_device *bdev, int rw)
{
struct blk_integrity *bi = bdev_get_integrity(bdev);
if (bi == NULL)
return 0;
if (rw == READ && bi->verify_fn != NULL &&
(bi->flags & INTEGRITY_FLAG_READ))
return 1;
if (rw == WRITE && bi->generate_fn != NULL &&
(bi->flags & INTEGRITY_FLAG_WRITE))
return 1;
return 0;
}
/**
* bio_integrity_enabled - Check whether integrity can be passed
* @bio: bio to check
*
* Description: Determines whether bio_integrity_prep() can be called
* on this bio or not. bio data direction and target device must be
* set prior to calling. The functions honors the write_generate and
* read_verify flags in sysfs.
*/
bool bio_integrity_enabled(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
if (!bio_is_rw(bio))
return false;
/* Already protected? */
if (bio_integrity(bio))
return false;
if (bi == NULL)
return false;
if (bio_data_dir(bio) == READ && bi->verify_fn != NULL &&
(bi->flags & BLK_INTEGRITY_VERIFY))
return true;
if (bio_data_dir(bio) == WRITE && bi->generate_fn != NULL &&
(bi->flags & BLK_INTEGRITY_GENERATE))
return true;
return false;
}
