The old code of copy_one_extent() is a mess:
- The main loop is implemented using goto
- @mirror_num is reset to 1 for each loop
- @mirror num check against @num_copies is wrong for decompression error
This patch will fix this mess by:
- Use read_extent_data()
read_extent_data() has all the good wrapping of btrfs_map_block()
and length check.
This removes a lot of complexity.
- Add extra file extent offset check
To prevent underflow for memory allocation
- Do proper mirror_num check for decompression error
Issue: #221
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
41ff76b833