Revert "Handle adb sync with Bionic under /bionic"
This reverts commit 530100996f60dbaefadab21624bcdf136fe00208.
Bug: 125549215
Test: system/core/fs_mgr/tests/adb-remount-test.sh
Change-Id: I4ee40cda9c3b94b116dc822c7b9736cfe2c9c9f0
diff --git a/daemon/file_sync_service.cpp b/daemon/file_sync_service.cpp
index 70deb31..29bd798 100644
--- a/daemon/file_sync_service.cpp
+++ b/daemon/file_sync_service.cpp
@@ -25,7 +25,6 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
@@ -211,22 +210,6 @@
return WriteFdExactly(s, &msg.dent, sizeof(msg.dent));
}
-static bool is_mountpoint(const std::string& path, pid_t tid) {
- const std::string mountinfo_path = "/proc/" + std::to_string(tid) + "/mountinfo";
- std::string mountinfo;
- if (!android::base::ReadFileToString(mountinfo_path, &mountinfo)) {
- PLOG(ERROR) << "Failed to open " << mountinfo_path;
- return false;
- }
- std::vector<std::string> lines = android::base::Split(mountinfo, "\n");
- return std::find_if(lines.begin(), lines.end(), [&path](const auto& line) {
- auto tokens = android::base::Split(line, " ");
- // line format is ...
- // mountid parentmountid major:minor sourcepath targetpath option ...
- return tokens.size() >= 4 && tokens[4] == path;
- }) != lines.end();
-}
-
// Make sure that SendFail from adb_io.cpp isn't accidentally used in this file.
#pragma GCC poison SendFail
@@ -432,18 +415,6 @@
struct stat st;
bool do_unlink = (lstat(path.c_str(), &st) == -1) || S_ISREG(st.st_mode) ||
(S_ISLNK(st.st_mode) && !S_ISLNK(mode));
-
- // If the path is a file that is a mount point, don't unlink it, but instead
- // truncate to zero. If unlinked, existing mounts on the path is all
- // unmounted
- if (S_ISREG(st.st_mode) && is_mountpoint(path, getpid())) {
- do_unlink = false;
- if (truncate(path.c_str(), 0) == -1) {
- SendSyncFail(s, "truncate to zero failed");
- return false;
- }
- }
-
if (do_unlink) {
adb_unlink(path.c_str());
}
@@ -591,64 +562,7 @@
return true;
}
-#if defined(__ANDROID__)
-class FileSyncPreparer {
- public:
- FileSyncPreparer() : saved_ns_fd_(-1), rooted_(getuid() == 0) {
- const std::string namespace_path = "/proc/" + std::to_string(gettid()) + "/ns/mnt";
- const int ns_fd = adb_open(namespace_path.c_str(), O_RDONLY | O_CLOEXEC);
- if (ns_fd == -1) {
- if (rooted_) PLOG(ERROR) << "Failed to save mount namespace";
- return;
- }
- saved_ns_fd_.reset(ns_fd);
-
- // Note: this is for the current thread only
- if (unshare(CLONE_NEWNS) != 0) {
- if (rooted_) PLOG(ERROR) << "Failed to clone mount namespace";
- return;
- }
-
- // Set the propagation type of / to private so that unmount below is
- // not propagated to other mount namespaces.
- if (mount(nullptr, "/", nullptr, MS_PRIVATE | MS_REC, nullptr) == -1) {
- if (rooted_) PLOG(ERROR) << "Could not change propagation type of / to MS_PRIVATE";
- return;
- }
-
- // unmount /bionic which is bind-mount to itself by init. Under /bionic,
- // there are other bind mounts for the bionic files. By unmounting this,
- // we unmount them all thus revealing the raw file system that is the
- // same as the local file system seen by the adb client.
- if (umount2("/bionic", MNT_DETACH) == -1 && errno != ENOENT) {
- if (rooted_) PLOG(ERROR) << "Could not unmount /bionic to reveal raw filesystem";
- return;
- }
- }
-
- ~FileSyncPreparer() {
- if (saved_ns_fd_.get() != -1) {
- // In fact, this is not strictly required because this thread for file
- // sync service will be destroyed after the current transfer is all
- // done. However, let's restore the ns in case the same thread is
- // reused by multiple transfers in the future refactoring.
- if (setns(saved_ns_fd_, CLONE_NEWNS) == -1) {
- PLOG(ERROR) << "Failed to restore saved mount namespace";
- }
- }
- }
-
- private:
- unique_fd saved_ns_fd_;
- bool rooted_;
-};
-#endif
-
void file_sync_service(unique_fd fd) {
-#if defined(__ANDROID__)
- FileSyncPreparer preparer;
-#endif
-
std::vector<char> buffer(SYNC_DATA_MAX);
while (handle_sync_command(fd.get(), buffer)) {
