fs_mgr: Add fs_mgr_flag overlayfs_remove_missing_lowerdir
If this flag is given, then fs_mgr_mount_overlayfs_fstab_entry() shall
filter out missing directories in the lowerdir= list.
For example,
test /mnt/vendor/overlay_test overlay \
ro,lowerdir=/dir1:/dir2:/missing_dir3 \
first_stage_mount,overlayfs_remove_missing_lowerdir
should mount the overlayfs device with "lowerdir=/dir1:/dir2".
Bug: 186342252
Test: Manual boot test with modified fstab on CF
Change-Id: Id06b37d0c236528cef981e495280b4f4e9c2b4bb
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 01c8ad3..d38fd7e 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -2322,7 +2322,24 @@
return false;
}
- auto options = "lowerdir=" + entry.lowerdir;
+ auto lowerdir = entry.lowerdir;
+ if (entry.fs_mgr_flags.overlayfs_remove_missing_lowerdir) {
+ bool removed_any = false;
+ std::vector<std::string> lowerdirs;
+ for (const auto& dir : android::base::Split(entry.lowerdir, ":")) {
+ if (access(dir.c_str(), F_OK)) {
+ PWARNING << __FUNCTION__ << "(): remove missing lowerdir '" << dir << "'";
+ removed_any = true;
+ } else {
+ lowerdirs.push_back(dir);
+ }
+ }
+ if (removed_any) {
+ lowerdir = android::base::Join(lowerdirs, ":");
+ }
+ }
+
+ auto options = "lowerdir=" + lowerdir;
if (overlayfs_valid_result == OverlayfsValidResult::kOverrideCredsRequired) {
options += ",override_creds=off";
}
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index d0c89b9..230a703 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -181,6 +181,7 @@
CheckFlag("fsverity", fs_verity);
CheckFlag("metadata_csum", ext_meta_csum);
CheckFlag("fscompress", fs_compress);
+ CheckFlag("overlayfs_remove_missing_lowerdir", overlayfs_remove_missing_lowerdir);
#undef CheckFlag
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index f33768b..9a4ed46 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -86,6 +86,7 @@
bool fs_verity : 1;
bool ext_meta_csum : 1;
bool fs_compress : 1;
+ bool overlayfs_remove_missing_lowerdir : 1;
} fs_mgr_flags = {};
bool is_encryptable() const {