[PATCH 01/12] nilfs2: convert segment buffer to be folio-based

[Ryusuke Konishi <konishi.ryusuke@gmail.com>]

In the segment buffer (log buffer) implementation, two parts of the
block buffer, CRC calculation and bio preparation, are still
page-based, so convert them to folio-based.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/nilfs2/segbuf.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index dc431b4c34c9..e08cab03366b 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -205,7 +205,6 @@ static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
 {
 	struct buffer_head *bh;
 	struct nilfs_segment_summary *raw_sum;
-	void *kaddr;
 	u32 crc;
 
 	bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
@@ -220,9 +219,13 @@ static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
 		crc = crc32_le(crc, bh->b_data, bh->b_size);
 	}
 	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
-		kaddr = kmap_local_page(bh->b_page);
-		crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
-		kunmap_local(kaddr);
+		size_t offset = offset_in_folio(bh->b_folio, bh->b_data);
+		unsigned char *from;
+
+		/* Do not support block sizes larger than PAGE_SIZE */
+		from = kmap_local_folio(bh->b_folio, offset);
+		crc = crc32_le(crc, from, bh->b_size);
+		kunmap_local(from);
 	}
 	raw_sum->ss_datasum = cpu_to_le32(crc);
 }
@@ -374,7 +377,7 @@ static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
 				  struct nilfs_write_info *wi,
 				  struct buffer_head *bh)
 {
-	int len, err;
+	int err;
 
 	BUG_ON(wi->nr_vecs <= 0);
  repeat:
@@ -385,8 +388,8 @@ static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
 			(wi->nilfs->ns_blocksize_bits - 9);
 	}
 
-	len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
-	if (len == bh->b_size) {
+	if (bio_add_folio(wi->bio, bh->b_folio, bh->b_size,
+			  offset_in_folio(bh->b_folio, bh->b_data))) {
 		wi->end++;
 		return 0;
 	}
-- 
2.43.0