bcachefs: Fixes for 4.19

1 files changed, 29 insertions, 0 deletions

diff --git a/fs/bcachefs/util.h b/fs/bcachefs/util.h
index 0128daba5970..2b19a0038045 100644
--- a/fs/bcachefs/util.h
+++ b/fs/bcachefs/util.h
@@ -664,6 +664,35 @@ static inline void memset_u64s_tail(void *s, int c, unsigned bytes)
 	memset(s + bytes, c, rem);
 }
 
+static inline struct bio_vec next_contig_bvec(struct bio *bio,
+					      struct bvec_iter *iter)
+{
+	struct bio_vec bv = bio_iter_iovec(bio, *iter);
+
+	bio_advance_iter(bio, iter, bv.bv_len);
+#ifndef CONFIG_HIGHMEM
+	while (iter->bi_size) {
+		struct bio_vec next = bio_iter_iovec(bio, *iter);
+
+		if (page_address(bv.bv_page) + bv.bv_offset + bv.bv_len !=
+		    page_address(next.bv_page) + next.bv_offset)
+			break;
+
+		bv.bv_len += next.bv_len;
+		bio_advance_iter(bio, iter, next.bv_len);
+	}
+#endif
+	return bv;
+}
+
+#define __bio_for_each_contig_segment(bv, bio, iter, start)		\
+	for (iter = (start);						\
+	     (iter).bi_size &&						\
+		((bv = next_contig_bvec((bio), &(iter))), 1);)
+
+#define bio_for_each_contig_segment(bv, bio, iter)			\
+	__bio_for_each_contig_segment(bv, bio, iter, (bio)->bi_iter)
+
 void sort_cmp_size(void *base, size_t num, size_t size,
 	  int (*cmp_func)(const void *, const void *, size_t),
 	  void (*swap_func)(void *, void *, size_t));