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mount with original mount flags
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@HuskyDG
HuskyDG committed Jun 15, 2023
1 parent 9735613 commit 35812be
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Showing 2 changed files with 41 additions and 8 deletions.
16 changes: 11 additions & 5 deletions native/jni/main.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,8 @@ using namespace std;

#define TO_STR std::string("")

#define MNT_FLAGS (MS_LAZYTIME | MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_DIRSYNC | MS_NOATIME | MS_NODIRATIME | MS_RELATIME | MS_STRICTATIME | MS_NOSYMFOLLOW | MS_MANDLOCK | MS_SILENT)

int log_fd = -1;
std::string overlay_tmpdir = "";
std::vector<mount_info> mountinfo;
Expand Down Expand Up @@ -57,7 +59,7 @@ static int do_remount(int flags = 0, int exclude_flags = 0) {
int fd = open(info.data(), O_PATH);
string fd_path = "/proc/self/fd/";
fd_path += std::to_string(fd);
LOGD("%s [%s] (%s)\n", (mount(nullptr, fd_path.data(), nullptr, MS_REMOUNT | (stvfs.f_flag & ~exclude_flags) | flags, nullptr) == 0)?
LOGD("%s [%s] (%s)\n", (mount(nullptr, fd_path.data(), nullptr, MS_REMOUNT | (stvfs.f_flag & MNT_FLAGS & ~exclude_flags) | flags, nullptr) == 0)?
"remounted" : "remount failed", info.data(), mnt.type.data());
close(fd);
} else {
Expand Down Expand Up @@ -214,8 +216,10 @@ int main(int argc, const char **argv) {
std::reverse(mountinfo.begin(), mountinfo.end());
for (auto &info : SYSTEM_PARTITIONS ) {
struct stat st;
struct statvfs FS_BUF;
if (lstat(info.data(), &st) || !S_ISDIR(st.st_mode))
continue;
statvfs(info.data(), &FS_BUF);
std::string tmp_mount = overlay_tmpdir + info;
mkdirs(tmp_mount.data(), 0);

Expand Down Expand Up @@ -277,14 +281,14 @@ int main(int argc, const char **argv) {
// 1 - read-write default
// 2 - read-only locked

if (OVERLAY_MODE == 2 || xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | MS_NOATIME, opts.data())) {
if (OVERLAY_MODE == 2 || xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | (FS_BUF.f_flag & MNT_FLAGS), opts.data())) {
opts = TO_STR +
"lowerdir=" +
upperdir +
":" +
get_lowerdirs(module_list, info.data()) +
info;
if (xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | MS_NOATIME, opts.data())) {
if (xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | (FS_BUF.f_flag & MNT_FLAGS), opts.data())) {
LOGW("Unable to add [%s], ignore!\n", info.data());
continue;
}
Expand All @@ -299,8 +303,10 @@ int main(int argc, const char **argv) {
for (auto &mnt : mountinfo) {
auto info = mnt.target;
struct stat st;
struct statvfs FS_BUF;
if (stat(info.data(), &st))
continue;
statvfs(info.data(), &FS_BUF);
std::string tmp_mount = overlay_tmpdir + info;
std::string upperdir = upper + info;
std::string workerdir = worker + "/" + std::to_string(st.st_dev) + "/" + std::to_string(st.st_ino);
Expand Down Expand Up @@ -388,7 +394,7 @@ int main(int argc, const char **argv) {
// 1 - read-write default
// 2 - read-only locked

if (OVERLAY_MODE == 2 || xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | MS_NOATIME, opts.data())) {
if (OVERLAY_MODE == 2 || xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | (FS_BUF.f_flag & MNT_FLAGS), opts.data())) {
opts = TO_STR +
"lowerdir=" +
upperdir +
Expand All @@ -397,7 +403,7 @@ int main(int argc, const char **argv) {
info;
if (!str_empty(context_opt.data()))
opts += TO_STR + "," + context_opt;
if (xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | MS_NOATIME, opts.data())) {
if (xmount("overlay", tmp_mount.data(), "overlay", MS_RDONLY | (FS_BUF.f_flag & MNT_FLAGS), opts.data())) {
// for some reason, overlayfs does not support some filesystems such as vfat, tmpfs, f2fs
// then bind mount it back but we will not be able to modify its content
LOGW("mount overlayfs failed, fall to bind mount!\n");
Expand Down
33 changes: 30 additions & 3 deletions native/jni/utils.cpp
View file
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
#include "logging.hpp"
#include "base.hpp"
#include "utils.hpp"

char *random_strc(int n){
int urandom_fd = open("/dev/urandom", O_RDONLY);
Expand Down Expand Up @@ -29,7 +30,7 @@ bool fexist(const char *path) {
struct stat st;
return lstat(path, &st) == 0;
}

bool is_dir(const char *path) {
struct stat st;
Expand Down Expand Up @@ -142,9 +143,35 @@ int dump_file(const char *src, const char *dest) {

int verbose_mount(const char *a, const char *b, const char *c, int d, const char *e) {
int ret = mount(a,b,c,d,e);
std::string mount_opts = "";
if (d & MS_PRIVATE) mount_opts += ",private";
else if (d & MS_SLAVE) mount_opts += ",slave";
else if (d & MS_SHARED) mount_opts += ",shared";
else if (d & MS_UNBINDABLE) mount_opts += ",unbindable";
else {
if (d & MS_RDONLY) mount_opts += ",ro"; else if ((d & MS_BIND) == 0) mount_opts += ",rw";
if (d & MS_LAZYTIME) mount_opts += ",lazytime";
if (d & MS_NODEV) mount_opts += ",nodev";
if (d & MS_NOEXEC) mount_opts += ",noexec";
if (d & MS_NOSUID) mount_opts += ",nosuid";
if (d & MS_SYNCHRONOUS) mount_opts += ",sync";
if (d & MS_NOATIME) mount_opts += ",noatime";
if (d & MS_NODIRATIME) mount_opts += ",nodiratime";
if (d & MS_RELATIME) mount_opts += ",relatime";
if (d & MS_STRICTATIME) mount_opts += ",strictatime";
if (d & MS_NOSYMFOLLOW) mount_opts += ",nosymfollow";
if (d & MS_MANDLOCK) mount_opts += ",mand";
if (d & MS_SILENT) mount_opts += ",silent";
if (d & MS_REMOUNT) mount_opts += ",remount";
if (d & MS_BIND) mount_opts += ",bind";
}
if (d & MS_REC) mount_opts += ",rec";
if (e) {
mount_opts += std::string(",") + e;
}
if (ret == 0) {
LOGD("mount: %s%s%s%s\n", b, (a != nullptr && a[0] != '\0')? std::string(std::string(" <- ") + a).data() : "",
c? std::string(std::string(" (") + c + ")").data() : "", e? std::string(std::string(" [") + e + "]").data() : "");
c? std::string(std::string(" (") + c + ")").data() : "", (!str_empty(mount_opts.data()))? std::string(std::string(" [") + (mount_opts.data() + 1) + "]").data() : "");
} else {
PLOGE("mount: %s%s", (a != nullptr && a[0] != '\0')? std::string(std::string(a) + " -> ").data() : "", b);
}
Expand Down Expand Up @@ -217,6 +244,6 @@ int setfilecon(const char *path, const char *con) {
}

void freecon(char *con) {
free(con);
free(con);
}

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