@@ -659,24 +659,27 @@ static inline bool page_is_mergeable(const struct bio_vec *bv,
return true;
}
-/*
- * Check if the @page can be added to the current segment(@bv), and make
- * sure to call it only if page_is_mergeable(@bv, @page) is true
- */
-static bool can_add_page_to_seg(struct request_queue *q,
- struct bio_vec *bv, struct page *page, unsigned len,
- unsigned offset)
+static bool bio_try_merge_pc_page(struct request_queue *q, struct bio *bio,
+ struct page *page, unsigned len, unsigned off, bool *same_page)
{
+ struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
unsigned long mask = queue_segment_boundary(q);
phys_addr_t addr1 = page_to_phys(bv->bv_page) + bv->bv_offset;
- phys_addr_t addr2 = page_to_phys(page) + offset + len - 1;
+ phys_addr_t addr2 = page_to_phys(page) + off + len - 1;
+
+ if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
+ *same_page = true;
+ goto done;
+ }
if ((addr1 | mask) != (addr2 | mask))
return false;
-
if (bv->bv_len + len > queue_max_segment_size(q))
return false;
-
+ if (!page_is_mergeable(bv, page, len, off, false))
+ return false;
+done:
+ bv->bv_len += len;
return true;
}
@@ -701,6 +704,7 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
bool put_same_page)
{
struct bio_vec *bvec;
+ bool same_page = false;
/*
* cloned bio must not modify vec list
@@ -712,26 +716,18 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
return 0;
if (bio->bi_vcnt > 0) {
- bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
-
- if (page == bvec->bv_page &&
- offset == bvec->bv_offset + bvec->bv_len) {
- if (put_same_page)
+ if (bio_try_merge_pc_page(q, bio, page, len, offset,
+ &same_page)) {
+ if (put_same_page && same_page)
put_page(page);
- bvec->bv_len += len;
- goto done;
- }
-
- if (page_is_mergeable(bvec, page, len, offset, false) &&
- can_add_page_to_seg(q, bvec, page, len, offset)) {
- bvec->bv_len += len;
goto done;
}
/*
- * If the queue doesn't support SG gaps and adding this
- * offset would create a gap, disallow it.
+ * If the queue doesn't support SG gaps and adding this offset
+ * would create a gap, disallow it.
*/
+ bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
if (bvec_gap_to_prev(q, bvec, offset))
return 0;
}
Factor the case of trying to add to an existing segment in __bio_add_pc_page into a new helper that is similar to the regular bio case. Subsume the existing can_add_page_to_seg helper into this new one. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/bio.c | 44 ++++++++++++++++++++------------------------ 1 file changed, 20 insertions(+), 24 deletions(-)