This is needed now that libfiemap_writer reads from dm/name to find
device-mapper names.
Bug: 134536978
Test: gsi_tool install
Change-Id: I10e1234f2ea39c92b43ace97fa76878358dfc476
To install GSIs on external storage (such as sdcards), gsid needs some
additional privileges:
- proc_cmdline and device-tree access to call ReadDefaultFstab().
This is ultimately used to check whether system's dm-verity has
check_at_most_once enabled, which is disallowed with sdcards.
- vfat read/write access to write files to the sdcard. Note that
adopted sdcards are not supported here.
- read access to the sdcard block device. To enable this without
providing access to vold_block_device, a new sdcard_block_device
label was added. Devices must apply this label appropriately to
enable gsid access.
- FIBMAP access for VFAT filesystems, as they do not support FIEMAP.
This only appears to work by granting SYS_RAWIO.
Bug: 126230649
Test: adb shell su root gsi_tool install --install_dir=/mnt/media_rw/...
works without setenforce 0
Change-Id: I88d8d83e5f61d4c0490f912f226fe1fe38cd60ab
