static struct bio *
iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
{
struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
struct bio *bio;
/*
* Only allocate as many vector entries as the bio code allows us to,
* we'll loop later on until we have handled the whole request.
*/
if (sg_num > BIO_MAX_PAGES)
sg_num = BIO_MAX_PAGES;
bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
if (!bio) {
pr_err("Unable to allocate memory for bio\n");
return NULL;
}
bio->bi_bdev = ib_dev->ibd_bd;
bio->bi_private = cmd;
bio->bi_destructor = iblock_bio_destructor;
bio->bi_end_io = &iblock_bio_done;
bio->bi_sector = lba;
return bio;
}
struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
{
struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
if (bio)
bio->bi_destructor = bio_fs_destructor;
return bio;
}
/*-----------------------------------------------------------------
* IO routines that accept a list of pages.
*---------------------------------------------------------------*/
static void do_region(int rw, unsigned region, struct dm_io_region *where,
struct dpages *dp, struct io *io)
{
struct bio *bio;
struct page *page;
unsigned long len;
unsigned offset;
unsigned num_bvecs;
sector_t remaining = where->count;
/*
* where->count may be zero if rw holds a flush and we need to
* send a zero-sized flush.
*/
do {
/*
* Allocate a suitably sized-bio.
*/
num_bvecs = dm_sector_div_up(remaining,
(PAGE_SIZE >> SECTOR_SHIFT));
num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), num_bvecs);
bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
if (!bio) {
printk(KERN_WARNING "%s : %s() failed\n", __FILE__, __func__);
BUG_ON(1);
}
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
bio->bi_destructor = dm_bio_destructor;
store_io_and_region_in_bio(bio, io, region);
/*
* Try and add as many pages as possible.
*/
while (remaining) {
dp->get_page(dp, &page, &len, &offset);
len = min(len, to_bytes(remaining));
if (!bio_add_page(bio, page, len, offset))
break;
offset = 0;
remaining -= to_sector(len);
dp->next_page(dp);
}
atomic_inc(&io->count);
submit_bio(rw, bio);
} while (remaining);
}
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations
*
* This function may be called concurrently. If we allocate from the mempool
* concurrently, there is a possibility of deadlock. For example, if we have
* mempool of 256 pages, two processes, each wanting 256, pages allocate from
* the mempool concurrently, it may deadlock in a situation where both processes
* have allocated 128 pages and the mempool is exhausted.
*
* In order to avoid this scenario we allocate the pages under a mutex.
*
* In order to not degrade performance with excessive locking, we try
* non-blocking allocations without a mutex first but on failure we fallback
* to blocking allocations with a mutex.
*/
static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
{
struct crypt_config *cc = io->cc;
struct bio *clone;
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
unsigned i, len, remaining_size;
struct page *page;
struct bio_vec *bvec;
retry:
if (unlikely(gfp_mask & __GFP_WAIT))
mutex_lock(&cc->bio_alloc_lock);
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
if (!clone)
goto return_clone;
clone_init(io, clone);
remaining_size = size;
for (i = 0; i < nr_iovecs; i++) {
page = mempool_alloc(cc->page_pool, gfp_mask);
if (!page) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
gfp_mask |= __GFP_WAIT;
goto retry;
}
len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
bvec = &clone->bi_io_vec[clone->bi_vcnt++];
bvec->bv_page = page;
bvec->bv_len = len;
bvec->bv_offset = 0;
clone->bi_iter.bi_size += len;
remaining_size -= len;
}
return_clone:
if (unlikely(gfp_mask & __GFP_WAIT))
mutex_unlock(&cc->bio_alloc_lock);
return clone;
}
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations
* May return a smaller bio when running out of pages, indicated by
* *out_of_pages set to 1.
*/
static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
unsigned *out_of_pages)
{
struct crypt_config *cc = io->cc;
struct bio *clone;
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
unsigned i, len;
struct page *page;
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
if (!clone)
return NULL;
clone_init(io, clone);
*out_of_pages = 0;
for (i = 0; i < nr_iovecs; i++) {
page = mempool_alloc(cc->page_pool, gfp_mask);
if (!page) {
*out_of_pages = 1;
break;
}
/*
* If additional pages cannot be allocated without waiting,
* return a partially-allocated bio. The caller will then try
* to allocate more bios while submitting this partial bio.
*/
gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
if (!bio_add_page(clone, page, len, 0)) {
mempool_free(page, cc->page_pool);
break;
}
size -= len;
}
if (!clone->bi_size) {
bio_put(clone);
return NULL;
}
return clone;
}
/*
* Creates a bio that consists of range of complete bvecs.
*/
static struct bio *clone_bio(struct bio *bio, sector_t sector,
unsigned short idx, unsigned short bv_count,
unsigned int len, struct bio_set *bs)
{
struct bio *clone;
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
clone->bi_vcnt = idx + bv_count;
clone->bi_size = to_bytes(len);
clone->bi_flags &= ~(1 << BIO_SEG_VALID);
return clone;
}
static void do_region(int rw, unsigned region, struct dm_io_region *where,
struct dpages *dp, struct io *io)
{
struct bio *bio;
struct page *page;
unsigned long len;
unsigned offset;
unsigned num_bvecs;
sector_t remaining = where->count;
struct request_queue *q = bdev_get_queue(where->bdev);
sector_t discard_sectors;
do {
if (rw & REQ_DISCARD)
num_bvecs = 1;
else
num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT)));
bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
bio->bi_destructor = dm_bio_destructor;
store_io_and_region_in_bio(bio, io, region);
if (rw & REQ_DISCARD) {
discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
bio->bi_size = discard_sectors << SECTOR_SHIFT;
remaining -= discard_sectors;
} else while (remaining) {
dp->get_page(dp, &page, &len, &offset);
len = min(len, to_bytes(remaining));
if (!bio_add_page(bio, page, len, offset))
break;
offset = 0;
remaining -= to_sector(len);
dp->next_page(dp);
}
atomic_inc(&io->count);
submit_bio(rw, bio);
} while (remaining);
}
/*
* Creates a little bio that is just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
unsigned int len)
{
struct bio *clone;
struct bio_vec *bv = bio->bi_io_vec + idx;
clone = bio_alloc_bioset(GFP_NOIO, 1, dm_set);
*clone->bi_io_vec = *bv;
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
clone->bi_io_vec->bv_len = clone->bi_size;
return clone;
}
void test(int bio){
bio = bio_alloc_bioset ( gfp_mask , bio_segments ( bio_src ) , bs ) ;}
/*-----------------------------------------------------------------
* IO routines that accept a list of pages.
*---------------------------------------------------------------*/
static void do_region(int rw, unsigned region, struct dm_io_region *where,
struct dpages *dp, struct io *io)
{
struct bio *bio;
struct page *page;
unsigned long len;
unsigned offset;
unsigned num_bvecs;
sector_t remaining = where->count;
struct request_queue *q = bdev_get_queue(where->bdev);
unsigned short logical_block_size = queue_logical_block_size(q);
sector_t num_sectors;
unsigned int uninitialized_var(special_cmd_max_sectors);
/*
* Reject unsupported discard and write same requests.
*/
if (rw & REQ_DISCARD)
special_cmd_max_sectors = q->limits.max_discard_sectors;
else if (rw & REQ_WRITE_SAME)
special_cmd_max_sectors = q->limits.max_write_same_sectors;
if ((rw & (REQ_DISCARD | REQ_WRITE_SAME)) && special_cmd_max_sectors == 0) {
dec_count(io, region, -EOPNOTSUPP);
return;
}
/*
* where->count may be zero if rw holds a flush and we need to
* send a zero-sized flush.
*/
do {
/*
* Allocate a suitably sized-bio.
*/
if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME))
num_bvecs = 1;
else
num_bvecs = min_t(int, BIO_MAX_PAGES,
dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT)));
bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
bio->bi_iter.bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
store_io_and_region_in_bio(bio, io, region);
if (rw & REQ_DISCARD) {
num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
remaining -= num_sectors;
} else if (rw & REQ_WRITE_SAME) {
/*
* WRITE SAME only uses a single page.
*/
dp->get_page(dp, &page, &len, &offset);
bio_add_page(bio, page, logical_block_size, offset);
num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
offset = 0;
remaining -= num_sectors;
dp->next_page(dp);
} else while (remaining) {
/*
* Try and add as many pages as possible.
*/
dp->get_page(dp, &page, &len, &offset);
len = min(len, to_bytes(remaining));
if (!bio_add_page(bio, page, len, offset))
break;
offset = 0;
remaining -= to_sector(len);
dp->next_page(dp);
}
atomic_inc(&io->count);
submit_bio(rw, bio);
} while (remaining);
}
