[PATCH 01/25] filemap: fix skip logic

Ed Bartosh
2017-06-08T16:15:01Z

Fixed bug in processing 'skip' parameter:
don't read input file if end of bmap block is less than skip

Simplified logic of positioning to the start of data inside a
partially skipped bmap block.

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
---
scripts/lib/wic/filemap.py | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py
index 1f1aacc..585b7ea 100644
--- a/scripts/lib/wic/filemap.py
+++ b/scripts/lib/wic/filemap.py
@@ -545,11 +545,14 @@ def sparse_copy(src_fname, dst_fname, offset=0, skip=0, api=None):
start = first * fmap.block_size
end = (last + 1) * fmap.block_size

+ if skip >= end:
+ continue
+
if start < skip < end:
- fmap._f_image.seek(skip, os.SEEK_SET)
- else:
- fmap._f_image.seek(start, os.SEEK_SET)
- dst_file.seek(offset + start, os.SEEK_SET)
+ start = skip
+
+ fmap._f_image.seek(start, os.SEEK_SET)
+ dst_file.seek(offset + start - skip, os.SEEK_SET)

chunk_size = 1024 * 1024
to_read = end - start
--
2.1.4