Merge "adb: use /system/bin/remount command" am: d458066bc7
am: bc0887add7
Change-Id: I3f6725ac4cbb181210f1f91b159cd31674f1b690
diff --git a/adb/Android.bp b/adb/Android.bp
index 3813578..1e085a7 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -402,6 +402,14 @@
"liblog",
],
+ product_variables: {
+ debuggable: {
+ required: [
+ "remount",
+ ],
+ },
+ },
+
target: {
android: {
srcs: [
diff --git a/adb/daemon/remount_service.cpp b/adb/daemon/remount_service.cpp
index 5e6d416..7999ddc 100644
--- a/adb/daemon/remount_service.cpp
+++ b/adb/daemon/remount_service.cpp
@@ -14,339 +14,81 @@
* limitations under the License.
*/
-#define TRACE_TAG ADB
-
-#include "sysdeps.h"
-
#include <errno.h>
#include <fcntl.h>
-#include <mntent.h>
-#include <spawn.h>
-#include <stdio.h>
-#include <stdlib.h>
#include <string.h>
-#include <sys/mount.h>
-#include <sys/statvfs.h>
-#include <sys/vfs.h>
+#include <sys/types.h>
+#include <sys/wait.h>
#include <unistd.h>
-#include <memory>
-#include <set>
#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>
-#include <fs_mgr.h>
-#include <fs_mgr_overlayfs.h>
#include "adb.h"
#include "adb_io.h"
#include "adb_unique_fd.h"
-#include "adb_utils.h"
-#include "set_verity_enable_state_service.h"
-
-using android::base::Realpath;
-using android::fs_mgr::Fstab;
-using android::fs_mgr::ReadDefaultFstab;
-
-// 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.
-static std::string find_proc_mount(const char* dir) {
- std::unique_ptr<FILE, int(*)(FILE*)> fp(setmntent("/proc/mounts", "r"), endmntent);
- 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 (canonical_path == e->mnt_dir) {
- mnt_fsname = e->mnt_fsname;
- }
- }
- return mnt_fsname;
-}
-
-// Returns the device used to mount a directory in the fstab.
-static std::string find_fstab_mount(const char* dir) {
- Fstab fstab;
- if (!ReadDefaultFstab(&fstab)) {
- return "";
- }
-
- auto entry = std::find_if(fstab.begin(), fstab.end(),
- [&dir](const auto& entry) { return entry.mount_point == dir; });
- if (entry == fstab.end()) {
- return "";
- }
- if (entry->fs_mgr_flags.logical) {
- fs_mgr_update_logical_partition(&(*entry));
- }
- return entry->blk_device;
-}
-
-// The proc entry for / is full of lies, so check fstab instead.
-// /proc/mounts lists rootfs and /dev/root, neither of which is what we want.
-static std::string find_mount(const char* dir, bool is_root) {
- if (is_root) {
- return find_fstab_mount(dir);
- } else {
- return find_proc_mount(dir);
- }
-}
-
-bool dev_is_overlayfs(const std::string& dev) {
- return (dev == "overlay") || (dev == "overlayfs");
-}
-
-bool make_block_device_writable(const std::string& dev) {
- if (dev_is_overlayfs(dev)) return true;
- int fd = unix_open(dev, O_RDONLY | O_CLOEXEC);
- if (fd == -1) {
- return false;
- }
-
- int OFF = 0;
- bool result = (ioctl(fd, BLKROSET, &OFF) != -1);
- unix_close(fd);
- return result;
-}
-
-static bool can_unshare_blocks(int fd, const char* dev) {
- const char* E2FSCK_BIN = "/system/bin/e2fsck";
- if (access(E2FSCK_BIN, X_OK)) {
- WriteFdFmt(fd, "e2fsck is not available, cannot undo deduplication on %s\n", dev);
- return false;
- }
-
- pid_t child;
- char* env[] = {nullptr};
- const char* argv[] = {E2FSCK_BIN, "-n", "-E", "unshare_blocks", dev, nullptr};
- if (posix_spawn(&child, E2FSCK_BIN, nullptr, nullptr, const_cast<char**>(argv), env)) {
- WriteFdFmt(fd, "failed to e2fsck to check deduplication: %s\n", strerror(errno));
- return false;
- }
- int status = 0;
- int ret = TEMP_FAILURE_RETRY(waitpid(child, &status, 0));
- if (ret < 0) {
- WriteFdFmt(fd, "failed to get e2fsck status: %s\n", strerror(errno));
- return false;
- }
- if (!WIFEXITED(status)) {
- WriteFdFmt(fd, "e2fsck exited abnormally with status %d\n", status);
- return false;
- }
- int rc = WEXITSTATUS(status);
- if (rc != 0) {
- WriteFdFmt(fd,
- "%s is deduplicated, and an e2fsck check failed. It might not "
- "have enough free-space to be remounted as writable.\n",
- dev);
- return false;
- }
- return true;
-}
-
-static unsigned long get_mount_flags(int fd, const char* dir) {
- struct statvfs st_vfs;
- if (statvfs(dir, &st_vfs) == -1) {
- // Even though we could not get the original mount flags, assume that
- // the mount was originally read-only.
- WriteFdFmt(fd, "statvfs of the %s mount failed: %s.\n", dir, strerror(errno));
- return MS_RDONLY;
- }
- return st_vfs.f_flag;
-}
-
-static bool remount_partition(int fd, const char* dir) {
- if (!directory_exists(dir)) {
- return true;
- }
- bool is_root = strcmp(dir, "/") == 0;
- if (is_root && dev_is_overlayfs(find_mount("/system", false))) {
- dir = "/system";
- is_root = false;
- }
- std::string dev = find_mount(dir, is_root);
- if (is_root && dev.empty()) {
- // The fstab entry will be /system if the device switched roots during
- // first-stage init.
- dev = find_mount("/system", true);
- }
- // Even if the device for the root is not found, we still try to remount it
- // as rw. This typically only happens when running Android in a container:
- // the root will almost always be in a loop device, which is dynamic, so
- // it's not convenient to put in the fstab.
- if (dev.empty() && !is_root) {
- return true;
- }
- if (!dev.empty() && !make_block_device_writable(dev)) {
- WriteFdFmt(fd, "remount of %s failed; couldn't make block device %s writable: %s\n",
- dir, dev.c_str(), strerror(errno));
- return false;
- }
-
- unsigned long remount_flags = get_mount_flags(fd, dir);
- remount_flags &= ~MS_RDONLY;
- remount_flags |= MS_REMOUNT;
-
- if (mount(dev.c_str(), dir, "none", remount_flags | MS_BIND, nullptr) == -1) {
- // This is useful for cases where the superblock is already marked as
- // read-write, but the mount itself is read-only, such as containers
- // where the remount with just MS_REMOUNT is forbidden by the kernel.
- WriteFdFmt(fd, "remount of the %s mount failed: %s.\n", dir, strerror(errno));
- return false;
- }
- if (mount(dev.c_str(), dir, "none", MS_REMOUNT, nullptr) == -1) {
- WriteFdFmt(fd, "remount of the %s superblock failed: %s\n", dir, strerror(errno));
- return false;
- }
- return true;
-}
-
-static void reboot_for_remount(int fd, bool need_fsck) {
- std::string reboot_cmd = "reboot";
- if (need_fsck) {
- const std::vector<std::string> options = {"--fsck_unshare_blocks"};
- std::string err;
- if (!write_bootloader_message(options, &err)) {
- WriteFdFmt(fd, "Failed to set bootloader message: %s\n", err.c_str());
- return;
- }
-
- WriteFdExactly(fd,
- "The device will now reboot to recovery and attempt "
- "un-deduplication.\n");
- reboot_cmd = "reboot,recovery";
- }
-
- sync();
- android::base::SetProperty(ANDROID_RB_PROPERTY, reboot_cmd.c_str());
-}
-
-static void try_unmount_bionic(int fd) {
- static constexpr const char* kBionic = "/bionic";
- struct statfs buf;
- if (statfs(kBionic, &buf) == -1) {
- WriteFdFmt(fd, "statfs of the %s mount failed: %s.\n", kBionic, strerror(errno));
- return;
- }
- if (buf.f_flags & ST_RDONLY) {
- // /bionic is on a read-only partition; can happen for
- // non-system-as-root-devices. Don' try to unmount.
- return;
- }
- // Success/Fail of the actual remount will be reported by the function.
- remount_partition(fd, kBionic);
- return;
-}
void remount_service(unique_fd fd, const std::string& cmd) {
- bool user_requested_reboot = cmd == "-R";
+ static constexpr char remount_cmd[] = "/system/bin/remount";
+ static constexpr char remount_failed[] = "remount failed\n";
if (getuid() != 0) {
WriteFdExactly(fd.get(), "Not running as root. Try \"adb root\" first.\n");
+ WriteFdExactly(fd.get(), remount_failed);
return;
}
- bool system_verified = !(android::base::GetProperty("partition.system.verified", "").empty());
- bool vendor_verified = !(android::base::GetProperty("partition.vendor.verified", "").empty());
-
- std::vector<std::string> partitions{"/", "/odm", "/oem", "/product_services",
- "/product", "/vendor"};
-
- if (system_verified || vendor_verified) {
- // Disable verity automatically (reboot will be required).
- set_verity_enabled_state_service(unique_fd(dup(fd.get())), false);
-
- // If overlayfs is not supported, we try and remount or set up
- // un-deduplication. If it is supported, we can go ahead and wait for
- // a reboot.
- if (fs_mgr_overlayfs_valid() != OverlayfsValidResult::kNotSupported) {
- if (user_requested_reboot) {
- if (android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot")) {
- WriteFdExactly(fd.get(), "rebooting device\n");
- } else {
- WriteFdExactly(fd.get(), "reboot failed\n");
- }
- }
- return;
- }
- } else if (fs_mgr_overlayfs_setup()) {
- // If we can use overlayfs, lets get it in place first before we
- // struggle with determining deduplication operations.
- Fstab fstab;
- if (ReadDefaultFstab(&fstab) && fs_mgr_overlayfs_mount_all(&fstab)) {
- WriteFdExactly(fd.get(), "overlayfs mounted\n");
- }
- }
-
- // If overlayfs is supported, we don't bother trying to un-deduplicate
- // partitions.
- std::set<std::string> dedup;
- if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
- // Find partitions that are deduplicated, and can be un-deduplicated.
- for (const auto& part : partitions) {
- auto partition = part;
- if ((part == "/") && !find_mount("/system", false).empty()) partition = "/system";
- std::string dev = find_mount(partition.c_str(), partition == "/");
- if (dev.empty() || !fs_mgr_has_shared_blocks(partition, dev)) {
- continue;
- }
- if (can_unshare_blocks(fd.get(), dev.c_str())) {
- dedup.emplace(partition);
- }
- }
-
- // Reboot now if the user requested it (and an operation needs a reboot).
- if (user_requested_reboot) {
- if (!dedup.empty()) {
- reboot_for_remount(fd.get(), !dedup.empty());
- return;
- }
- WriteFdExactly(fd.get(), "No reboot needed, skipping -R.\n");
- }
- }
-
- bool success = true;
- for (const auto& partition : partitions) {
- // Don't try to remount partitions that need an fsck in recovery.
- if (dedup.count(partition)) {
- continue;
- }
- success &= remount_partition(fd.get(), partition.c_str());
- }
-
- if (!dedup.empty()) {
- WriteFdExactly(fd.get(),
- "The following partitions are deduplicated and cannot "
- "yet be remounted:\n");
- for (const std::string& name : dedup) {
- WriteFdFmt(fd.get(), " %s\n", name.c_str());
- }
-
- WriteFdExactly(fd.get(),
- "To reboot and un-deduplicate the listed partitions, "
- "please retry with adb remount -R.\n");
- if (system_verified || vendor_verified) {
- WriteFdExactly(fd.get(), "Note: verity will be automatically disabled after reboot.\n");
- }
+ auto pid = vfork();
+ if (pid < 0) {
+ WriteFdFmt(fd.get(), "Failed to fork to %s: %s\n", remount_cmd, strerror(errno));
+ WriteFdExactly(fd.get(), remount_failed);
return;
}
- try_unmount_bionic(fd.get());
+ if (pid == 0) {
+ // child side of the fork
+ fcntl(fd.get(), F_SETFD, 0);
+ dup2(fd.get(), STDIN_FILENO);
+ dup2(fd.get(), STDOUT_FILENO);
+ dup2(fd.get(), STDERR_FILENO);
- if (!success) {
- WriteFdExactly(fd.get(), "remount failed\n");
- } else {
- WriteFdExactly(fd.get(), "remount succeeded\n");
+ execl(remount_cmd, remount_cmd, cmd.empty() ? nullptr : cmd.c_str(), nullptr);
+ _exit(-errno ?: 42);
}
+
+ int wstatus = 0;
+ auto ret = waitpid(pid, &wstatus, 0);
+
+ if (ret == -1) {
+ WriteFdFmt(fd.get(), "Failed to wait for %s: %s\n", remount_cmd, strerror(errno));
+ goto err;
+ }
+
+ if (ret != pid) {
+ WriteFdFmt(fd.get(), "pid %d and waitpid return %d do not match for %s\n",
+ static_cast<int>(pid), static_cast<int>(ret), remount_cmd);
+ goto err;
+ }
+
+ if (WIFSIGNALED(wstatus)) {
+ WriteFdFmt(fd.get(), "%s terminated with signal %s\n", remount_cmd,
+ strsignal(WTERMSIG(wstatus)));
+ goto err;
+ }
+
+ if (!WIFEXITED(wstatus)) {
+ WriteFdFmt(fd.get(), "%s stopped with status 0x%x\n", remount_cmd, wstatus);
+ goto err;
+ }
+
+ if (WEXITSTATUS(wstatus)) {
+ WriteFdFmt(fd.get(), "%s exited with status %d\n", remount_cmd,
+ static_cast<signed char>(WEXITSTATUS(wstatus)));
+ goto err;
+ }
+
+ WriteFdExactly(fd.get(), "remount succeeded\n");
+ return;
+
+err:
+ WriteFdExactly(fd.get(), remount_failed);
}
diff --git a/adb/daemon/remount_service.h b/adb/daemon/remount_service.h
index c847403..522a5da 100644
--- a/adb/daemon/remount_service.h
+++ b/adb/daemon/remount_service.h
@@ -21,6 +21,5 @@
#include "adb_unique_fd.h"
#if defined(__ANDROID__)
-bool make_block_device_writable(const std::string&);
void remount_service(unique_fd, const std::string&);
#endif
diff --git a/adb/daemon/set_verity_enable_state_service.cpp b/adb/daemon/set_verity_enable_state_service.cpp
index 92851c0..658261e 100644
--- a/adb/daemon/set_verity_enable_state_service.cpp
+++ b/adb/daemon/set_verity_enable_state_service.cpp
@@ -25,6 +25,7 @@
#include <libavb_user/libavb_user.h>
#include <stdarg.h>
#include <stdio.h>
+#include <sys/mount.h>
#include <sys/stat.h>
#include <android-base/properties.h>
@@ -37,7 +38,6 @@
#include "adb.h"
#include "adb_io.h"
#include "adb_unique_fd.h"
-#include "remount_service.h"
#include "fec/io.h"
@@ -51,6 +51,18 @@
if (getuid() != 0) WriteFdExactly(fd, "Maybe run adb root?\n");
}
+static bool make_block_device_writable(const std::string& dev) {
+ int fd = unix_open(dev, O_RDONLY | O_CLOEXEC);
+ if (fd == -1) {
+ return false;
+ }
+
+ int OFF = 0;
+ bool result = (ioctl(fd, BLKROSET, &OFF) != -1);
+ unix_close(fd);
+ return result;
+}
+
/* Turn verity on/off */
static bool set_verity_enabled_state(int fd, const char* block_device, const char* mount_point,
bool enable) {