fs_mgr: overlayfs: system as root can not detect shared blocks (taimen)
init first stage manufactures a / mount pointing to /dev/root and
we can not use that for checking the filesystem. Result is /system
overlay is mounted in second stage.
This adjustment to special case /dev/root is safe for overlayfs
handling because we will also gate on content in
/mnt/scratch/overlay/system, which will not be set during runtime
setup because check will have the proper block device at that time.
Test: adb-remount-test.sh
Bug: 123079041
Change-Id: I9c6674163955155f26ad2b0c9b78e9ff6507a514
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 9364b2d..3d5062c 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -157,7 +157,12 @@
fs_mgr_update_logical_partition(entry);
}
auto save_errno = errno;
+ errno = 0;
auto has_shared_blocks = fs_mgr_has_shared_blocks(entry->mount_point, entry->blk_device);
+ // special case for first stage init for system as root (taimen)
+ if (!has_shared_blocks && (errno == ENOENT) && (entry->blk_device == "/dev/root")) {
+ has_shared_blocks = true;
+ }
errno = save_errno;
return has_shared_blocks;
}