diff options
Diffstat (limited to 'scripts/lib/wic/filemap.py')
| -rw-r--r-- | scripts/lib/wic/filemap.py | 82 |
1 files changed, 32 insertions, 50 deletions
diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py index c53147c2f1..85b39d5d74 100644 --- a/scripts/lib/wic/filemap.py +++ b/scripts/lib/wic/filemap.py @@ -46,6 +46,13 @@ def get_block_size(file_obj): bsize = stat.st_blksize else: raise IOError("Unable to determine block size") + + # The logic in this script only supports a maximum of a 4KB + # block size + max_block_size = 4 * 1024 + if bsize > max_block_size: + bsize = max_block_size + return bsize class ErrorNotSupp(Exception): @@ -142,15 +149,6 @@ class _FilemapBase(object): raise Error("the method is not implemented") - def block_is_unmapped(self, block): # pylint: disable=W0613,R0201 - """ - This method has has to be implemented by child classes. It returns - 'True' if block number 'block' of the image file is not mapped (hole) - and 'False' otherwise. - """ - - raise Error("the method is not implemented") - def get_mapped_ranges(self, start, count): # pylint: disable=W0613,R0201 """ This method has has to be implemented by child classes. This is a @@ -164,15 +162,6 @@ class _FilemapBase(object): raise Error("the method is not implemented") - def get_unmapped_ranges(self, start, count): # pylint: disable=W0613,R0201 - """ - This method has has to be implemented by child classes. Just like - 'get_mapped_ranges()', but yields unmapped block ranges instead - (holes). - """ - - raise Error("the method is not implemented") - # The 'SEEK_HOLE' and 'SEEK_DATA' options of the file seek system call _SEEK_DATA = 3 @@ -265,15 +254,10 @@ class FilemapSeek(_FilemapBase): % (block, result)) return result - def block_is_unmapped(self, block): - """Refer the '_FilemapBase' class for the documentation.""" - return not self.block_is_mapped(block) - def _get_ranges(self, start, count, whence1, whence2): """ - This function implements 'get_mapped_ranges()' and - 'get_unmapped_ranges()' depending on what is passed in the 'whence1' - and 'whence2' arguments. + This function implements 'get_mapped_ranges()' depending + on what is passed in the 'whence1' and 'whence2' arguments. """ assert whence1 != whence2 @@ -303,12 +287,6 @@ class FilemapSeek(_FilemapBase): % (start, count, start + count - 1)) return self._get_ranges(start, count, _SEEK_DATA, _SEEK_HOLE) - def get_unmapped_ranges(self, start, count): - """Refer the '_FilemapBase' class for the documentation.""" - self._log.debug("FilemapSeek: get_unmapped_ranges(%d, %d(%d))" - % (start, count, start + count - 1)) - return self._get_ranges(start, count, _SEEK_HOLE, _SEEK_DATA) - # Below goes the FIEMAP ioctl implementation, which is not very readable # because it deals with the rather complex FIEMAP ioctl. To understand the @@ -422,10 +400,6 @@ class FilemapFiemap(_FilemapBase): % (block, result)) return result - def block_is_unmapped(self, block): - """Refer the '_FilemapBase' class for the documentation.""" - return not self.block_is_mapped(block) - def _unpack_fiemap_extent(self, index): """ Unpack a 'struct fiemap_extent' structure object number 'index' from @@ -502,23 +476,28 @@ class FilemapFiemap(_FilemapBase): % (first_prev, last_prev)) yield (first_prev, last_prev) - def get_unmapped_ranges(self, start, count): +class FilemapNobmap(_FilemapBase): + """ + This class is used when both the 'SEEK_DATA/HOLE' and FIEMAP are not + supported by the filesystem or kernel. + """ + + def __init__(self, image, log=None): """Refer the '_FilemapBase' class for the documentation.""" - self._log.debug("FilemapFiemap: get_unmapped_ranges(%d, %d(%d))" - % (start, count, start + count - 1)) - hole_first = start - for first, last in self._do_get_mapped_ranges(start, count): - if first > hole_first: - self._log.debug("FilemapFiemap: yielding range (%d, %d)" - % (hole_first, first - 1)) - yield (hole_first, first - 1) - hole_first = last + 1 + # Call the base class constructor first + _FilemapBase.__init__(self, image, log) + self._log.debug("FilemapNobmap: initializing") + + def block_is_mapped(self, block): + """Refer the '_FilemapBase' class for the documentation.""" + return True - if hole_first < start + count: - self._log.debug("FilemapFiemap: yielding range (%d, %d)" - % (hole_first, start + count - 1)) - yield (hole_first, start + count - 1) + def get_mapped_ranges(self, start, count): + """Refer the '_FilemapBase' class for the documentation.""" + self._log.debug("FilemapNobmap: get_mapped_ranges(%d, %d(%d))" + % (start, count, start + count - 1)) + yield (start, start + count -1) def filemap(image, log=None): """ @@ -533,7 +512,10 @@ def filemap(image, log=None): try: return FilemapFiemap(image, log) except ErrorNotSupp: - return FilemapSeek(image, log) + try: + return FilemapSeek(image, log) + except ErrorNotSupp: + return FilemapNobmap(image, log) def sparse_copy(src_fname, dst_fname, skip=0, seek=0, length=0, api=None): |