Merge "adb: warn on remount if undoing deduplication is impossible"
diff --git a/adb/daemon/remount_service.cpp b/adb/daemon/remount_service.cpp
index 7876368..eb46903 100644
--- a/adb/daemon/remount_service.cpp
+++ b/adb/daemon/remount_service.cpp
@@ -21,6 +21,7 @@
#include <errno.h>
#include <fcntl.h>
#include <mntent.h>
+#include <spawn.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -106,6 +107,41 @@
return (info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SHARED_BLOCKS) != 0;
}
+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 bool remount_partition(int fd, const char* dir, std::vector<std::string>& dedup) {
if (!directory_exists(dir)) {
return true;
@@ -133,6 +169,9 @@
}
if (mount(dev.c_str(), dir, "none", MS_REMOUNT, nullptr) == -1) {
if (errno == EROFS && fs_has_shared_blocks(dev.c_str())) {
+ if (!can_unshare_blocks(fd, dev.c_str())) {
+ return false;
+ }
// We return true so remount_service() can detect that the only
// failure was deduplicated filesystems.
dedup.push_back(dev);
