block: Consolidate duplicated bio_trim() implementations

Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Jeremy Fitzhardinge <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Kent Overstreet 2013-08-07 11:14:32 -07:00 • committed by Jens Axboe
commit 6678d83f18
7 changed files with 61 additions and 108 deletions

View file

@ -1336,57 +1336,6 @@ static int blkfront_probe(struct xenbus_device *dev,
return 0;
}
/*
* This is a clone of md_trim_bio, used to split a bio into smaller ones
*/
static void trim_bio(struct bio *bio, int offset, int size)
{
/* 'bio' is a cloned bio which we need to trim to match
* the given offset and size.
* This requires adjusting bi_sector, bi_size, and bi_io_vec
*/
int i;
struct bio_vec *bvec;
int sofar = 0;
size <<= 9;
if (offset == 0 && size == bio->bi_size)
return;
bio->bi_sector += offset;
bio->bi_size = size;
offset <<= 9;
clear_bit(BIO_SEG_VALID, &bio->bi_flags);
while (bio->bi_idx < bio->bi_vcnt &&
bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
/* remove this whole bio_vec */
offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
bio->bi_idx++;
}
if (bio->bi_idx < bio->bi_vcnt) {
bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
}
/* avoid any complications with bi_idx being non-zero*/
if (bio->bi_idx) {
memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
bio->bi_vcnt -= bio->bi_idx;
bio->bi_idx = 0;
}
/* Make sure vcnt and last bv are not too big */
bio_for_each_segment(bvec, bio, i) {
if (sofar + bvec->bv_len > size)
bvec->bv_len = size - sofar;
if (bvec->bv_len == 0) {
bio->bi_vcnt = i;
break;
}
sofar += bvec->bv_len;
}
}
static void split_bio_end(struct bio *bio, int error)
{
struct split_bio *split_bio = bio->bi_private;
@ -1522,7 +1471,7 @@ static int blkif_recover(struct blkfront_info *info)
(unsigned int)(bio->bi_size >> 9) - offset);
cloned_bio = bio_clone(bio, GFP_NOIO);
BUG_ON(cloned_bio == NULL);
trim_bio(cloned_bio, offset, size);
bio_trim(cloned_bio, offset, size);
cloned_bio->bi_private = split_bio;
cloned_bio->bi_end_io = split_bio_end;
submit_bio(cloned_bio->bi_rw, cloned_bio);