[PATCH 2/9] btrfs: set ->file_offset in end_bio_extent_readpage

[Christoph Hellwig <hch@lst.de>]

The new repair code expects ->file_offset to be set for all bios.  Set
it just after entering end_bio_extent_readpage.  As that requires looking
at the first vector before the first loop iteration also use that
opportunity to set various file-wide variables just once instead of once
per loop iteration.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/extent_io.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 48463705ef0e6..54a0ec62c7b0d 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3009,25 +3009,30 @@ static struct extent_buffer *find_extent_buffer_readpage(
  */
 static void end_bio_extent_readpage(struct bio *bio)
 {
+	struct bio_vec *first_vec = bio_first_bvec_all(bio);
+	struct inode *inode = first_vec->bv_page->mapping->host;
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	const u32 sectorsize = fs_info->sectorsize;
 	struct bio_vec *bvec;
 	struct btrfs_bio *bbio = btrfs_bio(bio);
-	struct extent_io_tree *tree, *failure_tree;
+	int mirror = bbio->mirror_num;
+	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+	struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
+	bool uptodate = !bio->bi_status;
 	struct processed_extent processed = { 0 };
 	/*
 	 * The offset to the beginning of a bio, since one bio can never be
 	 * larger than UINT_MAX, u32 here is enough.
 	 */
 	u32 bio_offset = 0;
-	int mirror;
 	struct bvec_iter_all iter_all;
 
+	btrfs_bio(bio)->file_offset =
+		page_offset(first_vec->bv_page) + first_vec->bv_offset;
+
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
 	bio_for_each_segment_all(bvec, bio, iter_all) {
-		bool uptodate = !bio->bi_status;
 		struct page *page = bvec->bv_page;
-		struct inode *inode = page->mapping->host;
-		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-		const u32 sectorsize = fs_info->sectorsize;
 		unsigned int error_bitmap = (unsigned int)-1;
 		bool repair = false;
 		u64 start;
@@ -3037,9 +3042,7 @@ static void end_bio_extent_readpage(struct bio *bio)
 		btrfs_debug(fs_info,
 			"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
 			bio->bi_iter.bi_sector, bio->bi_status,
-			bbio->mirror_num);
-		tree = &BTRFS_I(inode)->io_tree;
-		failure_tree = &BTRFS_I(inode)->io_failure_tree;
+			mirror);
 
 		/*
 		 * We always issue full-sector reads, but if some block in a
@@ -3062,7 +3065,6 @@ static void end_bio_extent_readpage(struct bio *bio)
 		end = start + bvec->bv_len - 1;
 		len = bvec->bv_len;
 
-		mirror = bbio->mirror_num;
 		if (likely(uptodate)) {
 			if (is_data_inode(inode)) {
 				error_bitmap = btrfs_verify_data_csum(bbio,
-- 
2.30.2