Add unmountTree to utils.
Bug: 111890351
Test: builds without any errors
Change-Id: I62a94c9e8d101756b686b402774f08a1d71cf875
diff --git a/Utils.cpp b/Utils.cpp
index 9773cc0..cdca85e 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -31,6 +31,8 @@
#include <dirent.h>
#include <fcntl.h>
#include <linux/fs.h>
+#include <mntent.h>
+#include <stdio.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/stat.h>
@@ -38,6 +40,7 @@
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <list>
#include <mutex>
#ifndef UMOUNT_NOFOLLOW
@@ -758,5 +761,32 @@
return android::base::GetBoolProperty("ro.kernel.qemu", false);
}
+status_t UnmountTree(const std::string& prefix) {
+ FILE* fp = setmntent("/proc/mounts", "r");
+ if (fp == NULL) {
+ PLOG(ERROR) << "Failed to open /proc/mounts";
+ return -errno;
+ }
+
+ // Some volumes can be stacked on each other, so force unmount in
+ // reverse order to give us the best chance of success.
+ std::list<std::string> toUnmount;
+ mntent* mentry;
+ while ((mentry = getmntent(fp)) != NULL) {
+ auto test = std::string(mentry->mnt_dir) + "/";
+ if (android::base::StartsWith(test, prefix)) {
+ toUnmount.push_front(test);
+ }
+ }
+ endmntent(fp);
+
+ for (const auto& path : toUnmount) {
+ if (umount2(path.c_str(), MNT_DETACH)) {
+ PLOG(ERROR) << "Failed to unmount " << path;
+ }
+ }
+ return OK;
+}
+
} // namespace vold
} // namespace android