[OE-core] [PATCH 09/35] wic: Remove fiemap support
Tom Zanussi
tom.zanussi at linux.intel.com
Fri Aug 8 22:05:34 UTC 2014
wic doesn't use it, so remove it.
Signed-off-by: Tom Zanussi <tom.zanussi at linux.intel.com>
---
scripts/lib/mic/utils/Fiemap.py | 252 ----------------------------------------
1 file changed, 252 deletions(-)
delete mode 100644 scripts/lib/mic/utils/Fiemap.py
diff --git a/scripts/lib/mic/utils/Fiemap.py b/scripts/lib/mic/utils/Fiemap.py
deleted file mode 100644
index f2db6ff..0000000
--- a/scripts/lib/mic/utils/Fiemap.py
+++ /dev/null
@@ -1,252 +0,0 @@
-""" This module implements python API for the FIEMAP ioctl. The FIEMAP ioctl
-allows to find holes and mapped areas in a file. """
-
-# Note, a lot of code in this module is not very readable, because it deals
-# with the rather complex FIEMAP ioctl. To understand the code, you need to
-# know the FIEMAP interface, which is documented in the
-# Documentation/filesystems/fiemap.txt file in the Linux kernel sources.
-
-# Disable the following pylint recommendations:
-# * Too many instance attributes (R0902)
-# pylint: disable=R0902
-
-import os
-import struct
-import array
-import fcntl
-from mic.utils.misc import get_block_size
-
-# Format string for 'struct fiemap'
-_FIEMAP_FORMAT = "=QQLLLL"
-# sizeof(struct fiemap)
-_FIEMAP_SIZE = struct.calcsize(_FIEMAP_FORMAT)
-# Format string for 'struct fiemap_extent'
-_FIEMAP_EXTENT_FORMAT = "=QQQQQLLLL"
-# sizeof(struct fiemap_extent)
-_FIEMAP_EXTENT_SIZE = struct.calcsize(_FIEMAP_EXTENT_FORMAT)
-# The FIEMAP ioctl number
-_FIEMAP_IOCTL = 0xC020660B
-
-# Minimum buffer which is required for 'class Fiemap' to operate
-MIN_BUFFER_SIZE = _FIEMAP_SIZE + _FIEMAP_EXTENT_SIZE
-# The default buffer size for 'class Fiemap'
-DEFAULT_BUFFER_SIZE = 256 * 1024
-
-class Error(Exception):
- """ A class for exceptions generated by this module. We currently support
- only one type of exceptions, and we basically throw human-readable problem
- description in case of errors. """
- pass
-
-class Fiemap:
- """ This class provides API to the FIEMAP ioctl. Namely, it allows to
- iterate over all mapped blocks and over all holes. """
-
- def _open_image_file(self):
- """ Open the image file. """
-
- try:
- self._f_image = open(self._image_path, 'rb')
- except IOError as err:
- raise Error("cannot open image file '%s': %s" \
- % (self._image_path, err))
-
- self._f_image_needs_close = True
-
- def __init__(self, image, buf_size = DEFAULT_BUFFER_SIZE):
- """ Initialize a class instance. The 'image' argument is full path to
- the file to operate on, or a file object to operate on.
-
- The 'buf_size' argument is the size of the buffer for 'struct
- fiemap_extent' elements which will be used when invoking the FIEMAP
- ioctl. The larger is the buffer, the less times the FIEMAP ioctl will
- be invoked. """
-
- self._f_image_needs_close = False
-
- if hasattr(image, "fileno"):
- self._f_image = image
- self._image_path = image.name
- else:
- self._image_path = image
- self._open_image_file()
-
- # Validate 'buf_size'
- if buf_size < MIN_BUFFER_SIZE:
- raise Error("too small buffer (%d bytes), minimum is %d bytes" \
- % (buf_size, MIN_BUFFER_SIZE))
-
- # How many 'struct fiemap_extent' elements fit the buffer
- buf_size -= _FIEMAP_SIZE
- self._fiemap_extent_cnt = buf_size / _FIEMAP_EXTENT_SIZE
- self._buf_size = self._fiemap_extent_cnt * _FIEMAP_EXTENT_SIZE
- self._buf_size += _FIEMAP_SIZE
-
- # Allocate a mutable buffer for the FIEMAP ioctl
- self._buf = array.array('B', [0] * self._buf_size)
-
- self.image_size = os.fstat(self._f_image.fileno()).st_size
-
- try:
- self.block_size = get_block_size(self._f_image)
- except IOError as err:
- raise Error("cannot get block size for '%s': %s" \
- % (self._image_path, err))
-
- self.blocks_cnt = self.image_size + self.block_size - 1
- self.blocks_cnt /= self.block_size
-
- # Synchronize the image file to make sure FIEMAP returns correct values
- try:
- self._f_image.flush()
- except IOError as err:
- raise Error("cannot flush image file '%s': %s" \
- % (self._image_path, err))
- try:
- os.fsync(self._f_image.fileno()),
- except OSError as err:
- raise Error("cannot synchronize image file '%s': %s " \
- % (self._image_path, err.strerror))
-
- # Check if the FIEMAP ioctl is supported
- self.block_is_mapped(0)
-
- def __del__(self):
- """ The class destructor which closes the opened files. """
-
- if self._f_image_needs_close:
- self._f_image.close()
-
- def _invoke_fiemap(self, block, count):
- """ Invoke the FIEMAP ioctl for 'count' blocks of the file starting from
- block number 'block'.
-
- The full result of the operation is stored in 'self._buf' on exit.
- Returns the unpacked 'struct fiemap' data structure in form of a python
- list (just like 'struct.upack()'). """
-
- if block < 0 or block >= self.blocks_cnt:
- raise Error("bad block number %d, should be within [0, %d]" \
- % (block, self.blocks_cnt))
-
- # Initialize the 'struct fiemap' part of the buffer
- struct.pack_into(_FIEMAP_FORMAT, self._buf, 0, block * self.block_size,
- count * self.block_size, 0, 0,
- self._fiemap_extent_cnt, 0)
-
- try:
- fcntl.ioctl(self._f_image, _FIEMAP_IOCTL, self._buf, 1)
- except IOError as err:
- error_msg = "the FIEMAP ioctl failed for '%s': %s" \
- % (self._image_path, err)
- if err.errno == os.errno.EPERM or err.errno == os.errno.EACCES:
- # The FIEMAP ioctl was added in kernel version 2.6.28 in 2008
- error_msg += " (looks like your kernel does not support FIEMAP)"
-
- raise Error(error_msg)
-
- return struct.unpack(_FIEMAP_FORMAT, self._buf[:_FIEMAP_SIZE])
-
- def block_is_mapped(self, block):
- """ This function returns 'True' if block number 'block' of the image
- file is mapped and 'False' otherwise. """
-
- struct_fiemap = self._invoke_fiemap(block, 1)
-
- # The 3rd element of 'struct_fiemap' is the 'fm_mapped_extents' field.
- # If it contains zero, the block is not mapped, otherwise it is
- # mapped.
- return bool(struct_fiemap[3])
-
- def block_is_unmapped(self, block):
- """ This function returns 'True' if block number 'block' of the image
- file is not mapped (hole) and 'False' otherwise. """
-
- return not self.block_is_mapped(block)
-
- def _unpack_fiemap_extent(self, index):
- """ Unpack a 'struct fiemap_extent' structure object number 'index'
- from the internal 'self._buf' buffer. """
-
- offset = _FIEMAP_SIZE + _FIEMAP_EXTENT_SIZE * index
- return struct.unpack(_FIEMAP_EXTENT_FORMAT,
- self._buf[offset : offset + _FIEMAP_EXTENT_SIZE])
-
- def _do_get_mapped_ranges(self, start, count):
- """ Implements most the functionality for the 'get_mapped_ranges()'
- generator: invokes the FIEMAP ioctl, walks through the mapped
- extents and yields mapped block ranges. However, the ranges may be
- consecutive (e.g., (1, 100), (100, 200)) and 'get_mapped_ranges()'
- simply merges them. """
-
- block = start
- while block < start + count:
- struct_fiemap = self._invoke_fiemap(block, count)
-
- mapped_extents = struct_fiemap[3]
- if mapped_extents == 0:
- # No more mapped blocks
- return
-
- extent = 0
- while extent < mapped_extents:
- fiemap_extent = self._unpack_fiemap_extent(extent)
-
- # Start of the extent
- extent_start = fiemap_extent[0]
- # Starting block number of the extent
- extent_block = extent_start / self.block_size
- # Length of the extent
- extent_len = fiemap_extent[2]
- # Count of blocks in the extent
- extent_count = extent_len / self.block_size
-
- # Extent length and offset have to be block-aligned
- assert extent_start % self.block_size == 0
- assert extent_len % self.block_size == 0
-
- if extent_block > start + count - 1:
- return
-
- first = max(extent_block, block)
- last = min(extent_block + extent_count, start + count) - 1
- yield (first, last)
-
- extent += 1
-
- block = extent_block + extent_count
-
- def get_mapped_ranges(self, start, count):
- """ A generator which yields ranges of mapped blocks in the file. The
- ranges are tuples of 2 elements: [first, last], where 'first' is the
- first mapped block and 'last' is the last mapped block.
-
- The ranges are yielded for the area of the file of size 'count' blocks,
- starting from block 'start'. """
-
- iterator = self._do_get_mapped_ranges(start, count)
-
- first_prev, last_prev = iterator.next()
-
- for first, last in iterator:
- if last_prev == first - 1:
- last_prev = last
- else:
- yield (first_prev, last_prev)
- first_prev, last_prev = first, last
-
- yield (first_prev, last_prev)
-
- def get_unmapped_ranges(self, start, count):
- """ Just like 'get_mapped_ranges()', but yields unmapped block ranges
- instead (holes). """
-
- hole_first = start
- for first, last in self._do_get_mapped_ranges(start, count):
- if first > hole_first:
- yield (hole_first, first - 1)
-
- hole_first = last + 1
-
- if hole_first < start + count:
- yield (hole_first, start + count - 1)
--
1.8.3.1
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