1 files changed, 33 insertions, 16 deletions

diff --git a/block/bio.c b/block/bio.c
index 4db1008309ed..83a2dfa417ca 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -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);
@@ -1072,8 +1080,9 @@ static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
 {
 	int i;
 	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		ssize_t ret;
 
 		ret = copy_page_from_iter(bvec->bv_page,
@@ -1103,8 +1112,9 @@ static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
 {
 	int i;
 	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		ssize_t ret;
 
 		ret = copy_page_to_iter(bvec->bv_page,
@@ -1126,8 +1136,9 @@ void bio_free_pages(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i)
+	bio_for_each_segment_all(bvec, bio, i, iter_all)
 		__free_page(bvec->bv_page);
 }
 EXPORT_SYMBOL(bio_free_pages);
@@ -1295,6 +1306,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
 	struct bio *bio;
 	int ret;
 	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
 
 	if (!iov_iter_count(iter))
 		return ERR_PTR(-EINVAL);
@@ -1368,7 +1380,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
 	return bio;
 
  out_unmap:
-	bio_for_each_segment_all(bvec, bio, j) {
+	bio_for_each_segment_all(bvec, bio, j, iter_all) {
 		put_page(bvec->bv_page);
 	}
 	bio_put(bio);
@@ -1379,11 +1391,12 @@ static void __bio_unmap_user(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	struct bvec_iter_all iter_all;
 
 	/*
 	 * make sure we dirty pages we wrote to
 	 */
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		if (bio_data_dir(bio) == READ)
 			set_page_dirty_lock(bvec->bv_page);
 
@@ -1475,8 +1488,9 @@ static void bio_copy_kern_endio_read(struct bio *bio)
 	char *p = bio->bi_private;
 	struct bio_vec *bvec;
 	int i;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
 		p += bvec->bv_len;
 	}
@@ -1585,8 +1599,9 @@ void bio_set_pages_dirty(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		if (!PageCompound(bvec->bv_page))
 			set_page_dirty_lock(bvec->bv_page);
 	}
@@ -1596,8 +1611,9 @@ static void bio_release_pages(struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i)
+	bio_for_each_segment_all(bvec, bio, i, iter_all)
 		put_page(bvec->bv_page);
 }
 
@@ -1644,8 +1660,9 @@ void bio_check_pages_dirty(struct bio *bio)
 	struct bio_vec *bvec;
 	unsigned long flags;
 	int i;
+	struct bvec_iter_all iter_all;
 
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all(bvec, bio, i, iter_all) {
 		if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page))
 			goto defer;
 	}