allow adb to remount symlink mount points
Currently `adb remount` won't remount symlink mount points.
In Android Generic System Image, there is a symlink
/product -> /system/product for devices with and without a physical
/product partition to work, respectively:
- Mount product partition under /system/product via
'mount /product' OR
- Keep using /product -> /system/product symlink,
when no product partition
Currently find_proc_mount() is seeking "/product" under /proc/mounts.
But the actual mount path is "/system/product" when GSI is used
on a device with product partition.
Bug: 111539442
Test: adb remount && touch /product/abc on both GSI and non-GSI
Change-Id: I8f15a67109d0a3f4ee18596ef7eb4280c5631b11
diff --git a/adb/daemon/remount_service.cpp b/adb/daemon/remount_service.cpp
index cf4d294..f55e025 100644
--- a/adb/daemon/remount_service.cpp
+++ b/adb/daemon/remount_service.cpp
@@ -35,6 +35,7 @@
#include <string>
#include <vector>
+#include <android-base/file.h>
#include <android-base/properties.h>
#include <bootloader_message/bootloader_message.h>
#include <cutils/android_reboot.h>
@@ -47,6 +48,8 @@
#include "adb_utils.h"
#include "set_verity_enable_state_service.h"
+using android::base::Realpath;
+
// Returns the last device used to mount a directory in /proc/mounts.
// This will find overlayfs entry where upperdir=lowerdir, to make sure
// remount is associated with the correct directory.
@@ -55,9 +58,15 @@
std::string mnt_fsname;
if (!fp) return mnt_fsname;
+ // dir might be a symlink, e.g., /product -> /system/product in GSI.
+ std::string canonical_path;
+ if (!Realpath(dir, &canonical_path)) {
+ PLOG(ERROR) << "Realpath failed: " << dir;
+ }
+
mntent* e;
while ((e = getmntent(fp.get())) != nullptr) {
- if (strcmp(dir, e->mnt_dir) == 0) {
+ if (canonical_path == e->mnt_dir) {
mnt_fsname = e->mnt_fsname;
}
}