btrfs-progs: convert: Fix a bug which fails to insert hole file extent

When copying inode, if there is a file referring part of a hole range,
convert will fail.

The problem is, when calculating real extent bytenr, it doesn't check if
the original extent is a hole.

In case the orinal extent is a hole, we still calculate bytenr using
file_pos - found_extent_file_pos, causing non-zero value, and later
btrfs_record_file_extent() detects that we are pointing to non-exist
extent and aborts convert.

Fix it by checking the disk_bytenr before calculating real disk bytenr.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/btrfs-convert.c b/btrfs-convert.c
index beec5d7..b18de59 100644 (file)
--- a/btrfs-convert.c
+++ b/btrfs-convert.c
@@ -572,7 +572,11 @@ static int record_file_blocks(struct blk_iterate_data *data,
                BUG_ON(cur_off - key.offset >= extent_num_bytes);
                btrfs_release_path(path);
 
-               real_disk_bytenr = cur_off - key.offset + extent_disk_bytenr;
+               if (extent_disk_bytenr)
+                       real_disk_bytenr = cur_off - key.offset +
+                                          extent_disk_bytenr;
+               else
+                       real_disk_bytenr = 0;
                cur_len = min(key.offset + extent_num_bytes,
                              old_disk_bytenr + num_bytes) - cur_off;
                ret = btrfs_record_file_extent(data->trans, data->root,