Commit d3f41317 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: send: update comment at find_extent_clone() 



We have this unclear comment at find_extent_clone() about extents starting
at a file offset greater than or equals to the i_size of the inode. It's
not really informative and it's misleading, since it mentions the author
found such extents with snapshots and large files.

Such extents are a result of fallocate with FALLOC_FL_KEEP_SIZE and there
is no relation to snapshots or large files (all write paths update the
i_size before inserting a new file extent item). So update the comment to
be precise about it and why we don't bother looking for clone sources in
that case.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 61ce908a

fs/btrfs/send.c

+7 −7
Original line number Diff line number Diff line
@@ -1365,14 +1365,14 @@ static int find_extent_clone(struct send_ctx *sctx, 
	int compressed;

	u32 i;



	if (data_offset >= ino_size) {

	/*

		 * There may be extents that lie behind the file's size.

		 * I at least had this in combination with snapshotting while

		 * writing large files.

	 * With fallocate we can get prealloc extents beyond the inode's i_size,

	 * so we don't do anything here because clone operations can not clone

	 * to a range beyond i_size without increasing the i_size of the

	 * destination inode.

	 */

	if (data_offset >= ino_size)

		return 0;

	}



	fi = btrfs_item_ptr(eb, path->slots[0], struct btrfs_file_extent_item);

	extent_type = btrfs_file_extent_type(eb, fi);