block: mark __bio_try_merge_page static

Mark __bio_try_merge_page static and move it up a bit to avoid the need
for a forward declaration.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012161804.991559-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-10-12 18:18:02 +02:00 committed by Jens Axboe
parent 9a6083becb
commit 9774b39175
2 changed files with 38 additions and 41 deletions

View File

@ -808,6 +808,44 @@ static inline bool page_is_mergeable(const struct bio_vec *bv,
return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE);
}
/**
* __bio_try_merge_page - try appending data to an existing bvec.
* @bio: destination bio
* @page: start page to add
* @len: length of the data to add
* @off: offset of the data relative to @page
* @same_page: return if the segment has been merged inside the same page
*
* Try to add the data at @page + @off to the last bvec of @bio. This is a
* useful optimisation for file systems with a block size smaller than the
* page size.
*
* Warn if (@len, @off) crosses pages in case that @same_page is true.
*
* Return %true on success or %false on failure.
*/
static bool __bio_try_merge_page(struct bio *bio, struct page *page,
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];
if (page_is_mergeable(bv, page, len, off, same_page)) {
if (bio->bi_iter.bi_size > UINT_MAX - len) {
*same_page = false;
return false;
}
bv->bv_len += len;
bio->bi_iter.bi_size += len;
return true;
}
}
return false;
}
/*
* Try to merge a page into a segment, while obeying the hardware segment
* size limit. This is not for normal read/write bios, but for passthrough
@ -939,45 +977,6 @@ int bio_add_zone_append_page(struct bio *bio, struct page *page,
}
EXPORT_SYMBOL_GPL(bio_add_zone_append_page);
/**
* __bio_try_merge_page - try appending data to an existing bvec.
* @bio: destination bio
* @page: start page to add
* @len: length of the data to add
* @off: offset of the data relative to @page
* @same_page: return if the segment has been merged inside the same page
*
* Try to add the data at @page + @off to the last bvec of @bio. This is a
* useful optimisation for file systems with a block size smaller than the
* page size.
*
* Warn if (@len, @off) crosses pages in case that @same_page is true.
*
* 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, 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];
if (page_is_mergeable(bv, page, len, off, same_page)) {
if (bio->bi_iter.bi_size > UINT_MAX - len) {
*same_page = false;
return false;
}
bv->bv_len += len;
bio->bi_iter.bi_size += len;
return true;
}
}
return false;
}
EXPORT_SYMBOL_GPL(__bio_try_merge_page);
/**
* __bio_add_page - add page(s) to a bio in a new segment
* @bio: destination bio

View File

@ -425,8 +425,6 @@ extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
int bio_add_zone_append_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset);
bool __bio_try_merge_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off, bool *same_page);
void __bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off);
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);