There are 4 partitions that are flashed at the factory and use F2FS fs with
4kb block size:
- /dev/block/by-name/efs
- /dev/block/by-name/efs_backup
- /dev/block/by-name/modem_userdata
- /dev/block/by-name/persist
These partitions can NOT be mounted by 16kb kernels because F2FS
expects BLOCK_SIZE == PAGE_SIZE.
In order to access the files in these partitions by 16kb kernels,
the dump.f2fs tool is used.
This change will perform these steps at boot time ONLY for 16kb mode. For
every partition (efs/efs_backup/modem_userdata/persist):
1. Use dump.f2fs to copy the content of the partition
to /data/vendor/copied/<partition name>.img.
2. If the copy was succesfull, rename /data/vendor/copied/<partition name>.img
to /data/vendor/copied/<partition name>
3. fsync the content of the directory /data/vendor/copied/<partition name>.
After the content of the partitions is in /data/vendor/copied,
bind-mount the partitions to the directory /mnt/vendor. See conf/fstab.efs.from_data.
Note: This change ONLY applies to 16kb kernels. This change does not modify
the original partitions.
Bug: 347015136
Bug: 362368691
Test: $ source build/envsetup.sh
$ lunch [zumapro]-trunk_staging-userdebug
$ m
$ ./vendor/google/tools/flashall -w
Flag: EXEMPT bugfix
Change-Id: Idf46a2a3a4f0b2e91ee4a0322a0c469e055684c8
60dc676409