btrfs: pass struct btrfs_inode to can_nocow_extent()

Pass a struct btrfs_inode to can_nocow_extent() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -532,7 +532,7 @@ int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
 			    u32 pgoff, u8 *csum, const u8 * const csum_expected);
 bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
 			u32 bio_offset, struct bio_vec *bv);
-noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
+noinline int can_nocow_extent(struct btrfs_inode *inode, u64 offset, u64 *len,
 			      struct btrfs_file_extent *file_extent,
 			      bool nowait);
 

fs/btrfs/direct-io.c

@@ -248,7 +248,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 		len = min(len, em->len - (start - em->start));
 		block_start = extent_map_block_start(em) + (start - em->start);
 
-		if (can_nocow_extent(inode, start, &len, &file_extent, false) == 1) {
+		if (can_nocow_extent(BTRFS_I(inode), start, &len, &file_extent,
+				     false) == 1) {
 			bg = btrfs_inc_nocow_writers(fs_info, block_start);
 			if (bg)
 				can_nocow = true;

fs/btrfs/file.c

@@ -1013,8 +1013,7 @@ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
 		btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend,
 						   &cached_state);
 	}
-	ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
-			       NULL, nowait);
+	ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, nowait);
 	if (ret <= 0)
 		btrfs_drew_write_unlock(&root->snapshot_lock);
 	else

fs/btrfs/inode.c

@@ -7075,17 +7075,17 @@ static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
  * NOTE: This only checks the file extents, caller is responsible to wait for
  *	 any ordered extents.
  */
-noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
+noinline int can_nocow_extent(struct btrfs_inode *inode, u64 offset, u64 *len,
 			      struct btrfs_file_extent *file_extent,
 			      bool nowait)
 {
-	struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct can_nocow_file_extent_args nocow_args = { 0 };
 	struct btrfs_path *path;
 	int ret;
 	struct extent_buffer *leaf;
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct extent_io_tree *io_tree = &inode->io_tree;
 	struct btrfs_file_extent_item *fi;
 	struct btrfs_key key;
 	int found_type;
@@ -7095,8 +7095,8 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 		return -ENOMEM;
 	path->nowait = nowait;
 
-	ret = btrfs_lookup_file_extent(NULL, root, path,
-			btrfs_ino(BTRFS_I(inode)), offset, 0);
+	ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
+				       offset, 0);
 	if (ret < 0)
 		goto out;
 
@@ -7111,7 +7111,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 	ret = 0;
 	leaf = path->nodes[0];
 	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-	if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
+	if (key.objectid != btrfs_ino(inode) ||
 	    key.type != BTRFS_EXTENT_DATA_KEY) {
 		/* not our file or wrong item type, must cow */
 		goto out;
@@ -7132,7 +7132,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 	nocow_args.end = offset + *len - 1;
 	nocow_args.free_path = true;
 
-	ret = can_nocow_file_extent(path, &key, BTRFS_I(inode), &nocow_args);
+	ret = can_nocow_file_extent(path, &key, inode, &nocow_args);
 	/* can_nocow_file_extent() has freed the path. */
 	path = NULL;
 
@@ -7148,7 +7148,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 				  nocow_args.file_extent.offset))
 		goto out;
 
-	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
+	if (!(inode->flags & BTRFS_INODE_NODATACOW) &&
 	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 		u64 range_end;