commit ccd094cd4e7b24e1209b3ad4a64d1a890b76010c
author Lianjun Huang <huanglianjun@xiaomi.corp-partner.google.com> Fri Feb 17 20:22:37 2023 +0800
committer Lianjun Huang <huanglianjun@xiaomi.corp-partner.google.com> Mon Feb 20 16:50:03 2023 +0800
tree 14c1db2b1288a23b10fee0d2dce362612063e3a7
parent 16ab2b67f7d42d14bd70f93910a3d9fad621452c

Fix failure on mounting system_ext partition

There can be more than one fstab entry of system partition.
For example, the filesystem of one entry is ext4 and another is erofs.

system /system ext4 ro wait,slotselect,avb=vbmeta_system,logical,first_stage_mount,avb_keys=/avb/q-gsi.avbpubkey:/avb/r-gsi.avbpubkey:/avb/s-gsi.avbpubkey
system /system erofs ro wait,slotselect,avb=vbmeta_system,logical,first_stage_mount,avb_keys=/avb/q-gsi.avbpubkey:/avb/r-gsi.avbpubkey:/avb/s-gsi.avbpubkey

If both filesystems of system and system_ext paritions are erofs,
only the ext4 fstab entry will be returned by GetEntryForMountPoint,
and system_ext cann't be mounted.

So we need to return both of the fstab entries and try all of them.

Signed-off-by: Lianjun Huang <huanglianjun@xiaomi.com>
Change-Id: I407553d48b1749cd0554f057a6bfd38daa96fdcb
Signed-off-by: Lianjun Huang <huanglianjun@xiaomi.corp-partner.google.com>

init/selinux.cpp

diff --git a/init/selinux.cpp b/init/selinux.cpp
index 4cc00fe..062ed39 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -897,29 +897,31 @@
             continue;
         }
 
-        auto system_entry = GetEntryForMountPoint(&fstab, "/system");
-        if (!system_entry) {
-            LOG(ERROR) << "Could not find mount entry for /system";
-            break;
-        }
-        if (!system_entry->fs_mgr_flags.logical) {
-            LOG(INFO) << "Skipping mount of " << name << ", system is not dynamic.";
-            break;
-        }
+        auto system_entries = GetEntriesForMountPoint(&fstab, "/system");
+        for (auto& system_entry : system_entries) {
+            if (!system_entry) {
+                LOG(ERROR) << "Could not find mount entry for /system";
+                break;
+            }
+            if (!system_entry->fs_mgr_flags.logical) {
+                LOG(INFO) << "Skipping mount of " << name << ", system is not dynamic.";
+                break;
+            }
 
-        auto entry = *system_entry;
-        auto partition_name = name + fs_mgr_get_slot_suffix();
-        auto replace_name = "system"s + fs_mgr_get_slot_suffix();
+            auto entry = *system_entry;
+            auto partition_name = name + fs_mgr_get_slot_suffix();
+            auto replace_name = "system"s + fs_mgr_get_slot_suffix();
 
-        entry.mount_point = "/"s + name;
-        entry.blk_device =
+            entry.mount_point = "/"s + name;
+            entry.blk_device =
                 android::base::StringReplace(entry.blk_device, replace_name, partition_name, false);
-        if (!fs_mgr_update_logical_partition(&entry)) {
-            LOG(ERROR) << "Could not update logical partition";
-            continue;
-        }
+            if (!fs_mgr_update_logical_partition(&entry)) {
+                LOG(ERROR) << "Could not update logical partition";
+                continue;
+            }
 
-        extra_fstab.emplace_back(std::move(entry));
+            extra_fstab.emplace_back(std::move(entry));
+        }
     }
 
     SkipMountingPartitions(&extra_fstab, true /* verbose */);