commit b6568cd4be17ae4807b6c03d7076bc79973e8478
author Tao Bao <tbao@google.com> Sat Jun 11 12:19:23 2016 -0700
committer Tao Bao <tbao@google.com> Sun Jul 10 23:15:48 2016 -0700
tree 19fc387c8982cb8572919f252336ed0f7d56c360
parent 8a09095c34c52084ad0d33873741f0eeddd294b5

releasetools: Disable using imgdiff for squashfs.

We use imgdiff to handle files in zip format (e.g. jar/zip/apk) for
higher compression ratio.

For system/vendor in squashfs, a) all files are compressed in LZ4
format; b) we use 4096-byte block size in their sparse images, but the
files in squashfs may not be laid out as 4K-aligned. So the blocks for
a given file as listed in block map may not form a valid zip file, which
may fail the patch generation with imgdiff.

Disable using imgdiff for squashfs images, and use bsdiff instead.

Bug: 22322817
Change-Id: Ie76aa4cece5c9d38cb1d1a34c505a4a8f37512d3
(cherry picked from commit 293fd135c7bc0c21b41f1782d21c26de64e8854a)

tools/releasetools/ota_from_target_files.py

diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 6966964..78751b4 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -866,9 +866,15 @@
   # disk type is ext4
   system_partition = OPTIONS.source_info_dict["fstab"]["/system"]
   check_first_block = system_partition.fs_type == "ext4"
+  # Disable using imgdiff for squashfs. 'imgdiff -z' expects input files to be
+  # in zip formats. However with squashfs, a) all files are compressed in LZ4;
+  # b) the blocks listed in block map may not contain all the bytes for a given
+  # file (because they're rounded to be 4K-aligned).
+  disable_imgdiff = system_partition.fs_type == "squashfs"
   system_diff = common.BlockDifference("system", system_tgt, system_src,
                                        check_first_block,
-                                       version=blockimgdiff_version)
+                                       version=blockimgdiff_version,
+                                       disable_imgdiff=disable_imgdiff)
 
   if HasVendorPartition(target_zip):
     if not HasVendorPartition(source_zip):
@@ -882,9 +888,11 @@
     # disk type is ext4
     vendor_partition = OPTIONS.source_info_dict["fstab"]["/vendor"]
     check_first_block = vendor_partition.fs_type == "ext4"
+    disable_imgdiff = vendor_partition.fs_type == "squashfs"
     vendor_diff = common.BlockDifference("vendor", vendor_tgt, vendor_src,
                                          check_first_block,
-                                         version=blockimgdiff_version)
+                                         version=blockimgdiff_version,
+                                         disable_imgdiff=disable_imgdiff)
   else:
     vendor_diff = None