block: enable multipage bvecs

This patch pulls the trigger for multi-page bvecs.

Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Ming Lei 2019-02-15 19:13:20 +08:00 • committed by Jens Axboe
commit 07173c3ec2
4 changed files with 20 additions and 12 deletions

View file

@ -753,6 +753,8 @@ EXPORT_SYMBOL(bio_add_pc_page);
* @page: page to add
* @len: length of the data to add
* @off: offset of the data in @page
* @same_page: if %true only merge if the new data is in the same physical
* page as the last segment of the bio.
*
* Try to add the data at @page + @off to the last bvec of @bio. This is a
* a useful optimisation for file systems with a block size smaller than the
@ -761,19 +763,25 @@ EXPORT_SYMBOL(bio_add_pc_page);
* Return %true on success or %false on failure.
*/
bool __bio_try_merge_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off)
unsigned int len, unsigned int off, bool same_page)
{
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return false;
if (bio->bi_vcnt > 0) {
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
bv->bv_offset + bv->bv_len - 1;
phys_addr_t page_addr = page_to_phys(page);
if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
bv->bv_len += len;
bio->bi_iter.bi_size += len;
return true;
}
if (vec_end_addr + 1 != page_addr + off)
return false;
if (same_page && (vec_end_addr & PAGE_MASK) != page_addr)
return false;
bv->bv_len += len;
bio->bi_iter.bi_size += len;
return true;
}
return false;
}
@ -819,7 +827,7 @@ EXPORT_SYMBOL_GPL(__bio_add_page);
int bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
if (!__bio_try_merge_page(bio, page, len, offset)) {
if (!__bio_try_merge_page(bio, page, len, offset, false)) {
if (bio_full(bio))
return 0;
__bio_add_page(bio, page, len, offset);