btrfs: get rid of at_offset parameter to btrfs_lookup_bio_sums()

We can encode this in the offset parameter: -1 means use the page
offsets, anything else is a valid offset.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -763,7 +763,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
 			if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
 				ret = btrfs_lookup_bio_sums(inode, comp_bio,
-							    false, 0, sums);
+							    (u64)-1, sums);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 
@@ -791,7 +791,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	BUG_ON(ret); /* -ENOMEM */
 
 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
-		ret = btrfs_lookup_bio_sums(inode, comp_bio, false, 0, sums);
+		ret = btrfs_lookup_bio_sums(inode, comp_bio, (u64)-1, sums);
 		BUG_ON(ret); /* -ENOMEM */
 	}
 

fs/btrfs/ctree.h

@@ -2789,7 +2789,7 @@ struct btrfs_dio_private;
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
 		    struct btrfs_root *root, u64 bytenr, u64 len);
 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   bool at_offset, u64 offset, u8 *dst);
+				   u64 offset, u8 *dst);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     u64 objectid, u64 pos,

fs/btrfs/file-item.c

@@ -152,17 +152,15 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
  * btrfs_lookup_bio_sums - Look up checksums for a bio.
  * @inode: inode that the bio is for.
  * @bio: bio embedded in btrfs_io_bio.
- * @at_offset: If true, look up checksums for the extent at @offset.
- *             If false, use the page offsets from the bio.
- * @offset: If @at_offset is true, offset in file to look up checksums for.
- *          Ignored otherwise.
+ * @offset: Unless (u64)-1, look up checksums for this offset in the file.
+ *          If (u64)-1, use the page offsets from the bio instead.
  * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If
  *       NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead.
  *
  * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
  */
 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   bool at_offset, u64 offset, u8 *dst)
+				   u64 offset, u8 *dst)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct bio_vec bvec;
@@ -171,6 +169,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
 	struct btrfs_csum_item *item = NULL;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	struct btrfs_path *path;
+	const bool page_offsets = (offset == (u64)-1);
 	u8 *csum;
 	u64 item_start_offset = 0;
 	u64 item_last_offset = 0;
@@ -223,7 +222,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
 		if (count)
 			goto next;
 
-		if (!at_offset)
+		if (page_offsets)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 		count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
 					       csum, nblocks);

fs/btrfs/inode.c

@@ -2127,7 +2127,7 @@ static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
 							   bio_flags);
 			goto out;
 		} else if (!skip_sum) {
-			ret = btrfs_lookup_bio_sums(inode, bio, false, 0, NULL);
+			ret = btrfs_lookup_bio_sums(inode, bio, (u64)-1, NULL);
 			if (ret)
 				goto out;
 		}
@@ -8387,8 +8387,8 @@ static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
 	 * contention.
 	 */
 	if (dip->logical_offset == file_offset) {
-		ret = btrfs_lookup_bio_sums(inode, dip->orig_bio, true,
-					    file_offset, NULL);
+		ret = btrfs_lookup_bio_sums(inode, dip->orig_bio, file_offset,
+					    NULL);
 		if (ret)
 			return ret;
 	}