static int kaio_kernel_submit(struct file *file, struct bio *bio,
struct ploop_request * preq, iblock_t iblk,
unsigned long rw)
{
struct kiocb *iocb;
unsigned short op;
struct iov_iter iter;
struct bio_vec *bvec;
size_t nr_segs;
loff_t pos = (loff_t) bio->bi_sector;
pos = ((loff_t)iblk << preq->plo->cluster_log) |
(pos & ((1<<preq->plo->cluster_log) - 1));
pos <<= 9;
iocb = aio_kernel_alloc(GFP_NOIO);
if (!iocb)
return -ENOMEM;
if (rw & (1<<BIO_RW))
op = IOCB_CMD_WRITE_ITER;
else
op = IOCB_CMD_READ_ITER;
bvec = bio_iovec_idx(bio, bio->bi_idx);
nr_segs = bio_segments(bio);
iov_iter_init_bvec(&iter, bvec, nr_segs, bvec_length(bvec, nr_segs), 0);
aio_kernel_init_iter(iocb, file, op, &iter, pos);
aio_kernel_init_callback(iocb, kaio_rw_aio_complete, (u64)preq);
return aio_kernel_submit(iocb);
}
double bvec_ber (bvec v1, bvec v2)
{
int lmin, lmax, d = 0;
idx_t i;
if (bvec_length (v1) > bvec_length (v2)) {
lmin = bvec_length (v2);
lmax = bvec_length (v1);
}
else {
lmin = bvec_length (v1);
lmax = bvec_length (v2);
}
for (i = 0; i < lmin; i++)
if (v1[i] != v2[i])
d++;
return (d + lmax - bvec_length (v2)) / (double) bvec_length (v1);
}
/*
* Pack as many bios from the list pointed by '*bio_pp' to kreq as possible,
* but no more than 'size' bytes. Returns 'copy' equal to # bytes copied.
*
* <*bio_pp, *idx_p> plays the role of iterator to walk through bio list.
* NB: the iterator is valid only while 'size' > 'copy'
*
* NB: at enter, '*nr_segs' depicts capacity of kreq;
* at return, it depicts actual payload
*/
static size_t kaio_kreq_pack(struct kaio_req *kreq, int *nr_segs,
struct bio **bio_pp, int *idx_p, size_t size)
{
int kreq_nr_max = *nr_segs;
struct bio *b = *bio_pp;
int idx = *idx_p;
struct bio_vec *src_bv = b->bi_io_vec + idx;
struct bio_vec *dst_bv = kreq->bvecs;
size_t copy = 0;
BUG_ON(b->bi_idx);
while (1) {
int nr = min_t(int, kreq_nr_max, b->bi_vcnt - idx);
BUG_ON(!nr);
memcpy(dst_bv, src_bv, nr * sizeof(struct bio_vec));
copy += bvec_length(dst_bv, nr);
if (copy >= size) {
*nr_segs = dst_bv - kreq->bvecs + nr;
return size;
}
dst_bv += nr;
src_bv += nr;
idx += nr;
if (b->bi_vcnt == idx) {
b = b->bi_next;
BUG_ON(!b);
src_bv = b->bi_io_vec;
idx = 0;
}
kreq_nr_max -= nr;
if (kreq_nr_max == 0)
break;
}
*bio_pp = b;
*idx_p = idx;
return copy;
}
int bvec_distance_hamming (bvec v1, bvec v2)
{
int lmin, lmax, d = 0;
idx_t i;
if (bvec_length (v1) > bvec_length (v2)) {
lmin = bvec_length (v2);
lmax = bvec_length (v1);
}
else {
lmin = bvec_length (v1);
lmax = bvec_length (v2);
}
for (i = 0; i < lmin; i++)
if (v1[i] != v2[i])
d++;
return d + lmax - lmin;
}
