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
This commit is contained in:
Bowgo Tsai 2018-09-28 12:05:02 +08:00
parent c2501fda60
commit 41649b871a
1 changed files with 10 additions and 1 deletions

View File

@ -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 @@ static std::string find_proc_mount(const char* dir) {
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;
}
}