1 files changed, 19 insertions, 74 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 41c77a100853..018c711a0bc8 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -336,48 +336,6 @@ out:
 }
 
 /*
- * Locate the file_offset of @cur_disk_bytenr of a @bio.
- *
- * Bio of btrfs represents read range of
- * [bi_sector << 9, bi_sector << 9 + bi_size).
- * Knowing this, we can iterate through each bvec to locate the page belong to
- * @cur_disk_bytenr and get the file offset.
- *
- * @inode is used to determine if the bvec page really belongs to @inode.
- *
- * Return 0 if we can't find the file offset
- * Return >0 if we find the file offset and restore it to @file_offset_ret
- */
-static int search_file_offset_in_bio(struct bio *bio, struct inode *inode,
-				     u64 disk_bytenr, u64 *file_offset_ret)
-{
-	struct bvec_iter iter;
-	struct bio_vec bvec;
-	u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT;
-	int ret = 0;
-
-	bio_for_each_segment(bvec, bio, iter) {
-		struct page *page = bvec.bv_page;
-
-		if (cur > disk_bytenr)
-			break;
-		if (cur + bvec.bv_len <= disk_bytenr) {
-			cur += bvec.bv_len;
-			continue;
-		}
-		ASSERT(in_range(disk_bytenr, cur, bvec.bv_len));
-		if (page->mapping && page->mapping->host &&
-		    page->mapping->host == inode) {
-			ret = 1;
-			*file_offset_ret = page_offset(page) + bvec.bv_offset +
-					   disk_bytenr - cur;
-			break;
-		}
-	}
-	return ret;
-}
-
-/*
  * Lookup the checksum for the read bio in csum tree.
  *
  * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
@@ -386,17 +344,15 @@ blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
 {
 	struct btrfs_inode *inode = bbio->inode;
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
-	struct extent_io_tree *io_tree = &inode->io_tree;
 	struct bio *bio = &bbio->bio;
 	struct btrfs_path *path;
 	const u32 sectorsize = fs_info->sectorsize;
 	const u32 csum_size = fs_info->csum_size;
 	u32 orig_len = bio->bi_iter.bi_size;
 	u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
-	u64 cur_disk_bytenr;
 	const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
-	int count = 0;
 	blk_status_t ret = BLK_STS_OK;
+	u32 bio_offset = 0;
 
 	if ((inode->flags & BTRFS_INODE_NODATASUM) ||
 	    test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
@@ -447,28 +403,14 @@ blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
 		path->skip_locking = 1;
 	}
 
-	for (cur_disk_bytenr = orig_disk_bytenr;
-	     cur_disk_bytenr < orig_disk_bytenr + orig_len;
-	     cur_disk_bytenr += (count * sectorsize)) {
-		u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr;
-		unsigned int sector_offset;
-		u8 *csum_dst;
-
-		/*
-		 * Although both cur_disk_bytenr and orig_disk_bytenr is u64,
-		 * we're calculating the offset to the bio start.
-		 *
-		 * Bio size is limited to UINT_MAX, thus unsigned int is large
-		 * enough to contain the raw result, not to mention the right
-		 * shifted result.
-		 */
-		ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX);
-		sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >>
-				fs_info->sectorsize_bits;
-		csum_dst = bbio->csum + sector_offset * csum_size;
+	while (bio_offset < orig_len) {
+		int count;
+		u64 cur_disk_bytenr = orig_disk_bytenr + bio_offset;
+		u8 *csum_dst = bbio->csum +
+			(bio_offset >> fs_info->sectorsize_bits) * csum_size;
 
 		count = search_csum_tree(fs_info, path, cur_disk_bytenr,
-					 search_len, csum_dst);
+					 orig_len - bio_offset, csum_dst);
 		if (count < 0) {
 			ret = errno_to_blk_status(count);
 			if (bbio->csum != bbio->csum_inline)
@@ -493,14 +435,9 @@ blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
 
 			if (inode->root->root_key.objectid ==
 			    BTRFS_DATA_RELOC_TREE_OBJECTID) {
-				u64 file_offset;
-				int ret;
-
-				ret = search_file_offset_in_bio(bio,
-						&inode->vfs_inode,
-						cur_disk_bytenr, &file_offset);
-				if (ret)
-					set_extent_bits(io_tree, file_offset,
+				u64 file_offset = bbio->file_offset + bio_offset;
+
+				set_extent_bits(&inode->io_tree, file_offset,
 						file_offset + sectorsize - 1,
 						EXTENT_NODATASUM);
 			} else {
@@ -509,6 +446,7 @@ blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
 				cur_disk_bytenr, cur_disk_bytenr + sectorsize);
 			}
 		}
+		bio_offset += count * sectorsize;
 	}
 
 	btrfs_free_path(path);
@@ -659,7 +597,8 @@ fail:
  * in is large enough to contain all csums.
  */
 int btrfs_lookup_csums_bitmap(struct btrfs_root *root, u64 start, u64 end,
-			      u8 *csum_buf, unsigned long *csum_bitmap)
+			      u8 *csum_buf, unsigned long *csum_bitmap,
+			      bool search_commit)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_key key;
@@ -676,6 +615,12 @@ int btrfs_lookup_csums_bitmap(struct btrfs_root *root, u64 start, u64 end,
 	if (!path)
 		return -ENOMEM;
 
+	if (search_commit) {
+		path->skip_locking = 1;
+		path->reada = READA_FORWARD;
+		path->search_commit_root = 1;
+	}
+
 	key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
 	key.type = BTRFS_EXTENT_CSUM_KEY;
 	key.offset = start;