Add support for erofs - #24
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This is built on top of the official erofs-utils project. Unfortunately, unlike e2fsprogs, erofs-utils doesn't really work well when used as a library. There are global variables everywhere and assumptions made based on how the official CLI tools consume the library. This is worked around by just having afsr's ErofsFilesystem take a global lock for its entire lifetime. For unpacking, the process is pretty straight forward. The erofs image is opened and read the same way as fuse.erofs does it. For packing, there is no library API for what mkfs.erofs does, so afsr embeds a copy of that command (like what is already done for mke2fs) and feeds it a tarball of the file contents and metadata. erofs-utils is not cross-platform and makes a lot of Linux-specific assumptions. afsr uses a fork of the project to add the bare minimum needed to allow it to also run on Windows and Mac. erofs-utils' multithreading support is built on top of the pthreads API, so the Windows builds are compiled without support for multithreading. Finally, unlike e2fsprogs, afsr is built on top of the upstream 1.9.4 release of erofs-utils instead of Android's android-17.0.0_r1 tag. Android's fork is based on an old version of erofs-utils that contains several memory safety issues. On Linux, they just make valgrind unhappy, but on Windows, they crash the process. Our fork includes some additional patches to fix other memory safety issues. Fixes: #14 Signed-off-by: Andrew Gunnerson <accounts+github@chiller3.com>
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Signed-off-by: Andrew Gunnerson <accounts+github@chiller3.com>
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This is built on top of the official erofs-utils project. Unfortunately, unlike e2fsprogs, erofs-utils doesn't really work well when used as a library. There are global variables everywhere and assumptions made based on how the official CLI tools consume the library. This is worked around by just having afsr's
ErofsFilesystemtake a global lock for its entire lifetime.For unpacking, the process is pretty straight forward. The erofs image is opened and read the same way as
fuse.erofsdoes it. For packing, there is no library API for whatmkfs.erofsdoes, so afsr embeds a copy of that command (like what is already done formke2fs) and feeds it a tarball of the file contents and metadata.erofs-utils is not cross-platform and makes a lot of Linux-specific assumptions. afsr uses a fork of the project to add the bare minimum needed to allow it to also run on Windows and Mac. erofs-utils' multithreading support is built on top of the pthreads API, so the Windows builds are compiled without support for multithreading.
Finally, unlike e2fsprogs, afsr is built on top of the upstream 1.9.4 release of erofs-utils instead of Android's
android-17.0.0_r1tag. Android's fork is based on an old version of erofs-utils that contains several memory safety issues. On Linux, they just make valgrind unhappy, but on Windows, they crash the process. Our fork includes some additional patches to fix other memory safety issues.Fixes: #14