Use partition name or devpath's name

native/src/core/bootstages.cpp

@@ -79,6 +79,7 @@ static void mount_mirrors() {
                 xmkdir(preinit_dir.data(), 0700);
                 auto mirror_dir = MAGISKTMP + "/" PREINITMIRR;
                 mount_mirror(preinit_dir, mirror_dir);
+                xmount(nullptr, mirror_dir.data(), nullptr, MS_UNBINDABLE, nullptr);
                 break;
             }
         }
@@ -109,23 +110,24 @@ static void mount_mirrors() {
     }
 }
 
-dev_t find_preinit_device() {
+string find_preinit_device() {
-    const int UNKNOWN = 0;
+    enum {
-    const int PERSIST = 1;
+        UNKNOWN,
-    const int METADATA = 2;
+        PERSIST,
-    const int CACHE = 3;
+        METADATA,
-    const int DATA = 4;
+        CACHE,
-    int matched = UNKNOWN;
+        DATA,
-    dev_t rules_dev = 0;
+    } matched = UNKNOWN;
     bool encrypted = getprop("ro.crypto.state") == "encrypted";
-    string preinit_dir;
-
     bool mount = getuid() == 0 && getenv("MAGISKTMP");
 
+    string preinit_source;
+    string preinit_dir;
+
     for (const auto &info: parse_mount_info("self")) {
         if (info.target.ends_with(PREINITMIRR))
-            return info.device;
+            return basename(info.source.data());
-        if (info.root != "/" || info.source.find("/dm-") != string::npos)
+        if (info.root != "/" || info.source[0] != '/' || info.source.find("/dm-") != string::npos)
             continue;
         if (info.type != "ext4" && info.type != "f2fs")
             continue;
@@ -134,27 +136,46 @@ dev_t find_preinit_device() {
             return flag == "rw"sv;
         });
         if (!rw) continue;
-        int new_matched;
+        if (auto base = std::string_view(info.source).substr(0, info.source.find_last_of('/'));
-        if (info.target == "/cache" && matched < CACHE) {
+            !base.ends_with("/by-name") && !base.ends_with("/block")) {
-            new_matched = CACHE;
+            continue;
-        } else if (info.target == "/data" && matched < DATA) {
+        }
-            if (encrypted && access("/data/unencrypted", F_OK)) {
+
+        switch (matched) {
+            case UNKNOWN:
+                if (info.target == "/persist" || info.target == "/mnt/vendor/persist") {
+                    matched = PERSIST;
+                    break;
+                }
+                [[fallthrough]];
+            case PERSIST:
+                if (info.target == "/metadata") {
+                    matched = METADATA;
+                    break;
+                }
+                [[fallthrough]];
+            case METADATA:
+                if (info.target == "/cache") {
+                    matched = CACHE;
+                    break;
+                }
+                [[fallthrough]];
+            case CACHE:
+                if (info.target == "/data") {
+                    if (!encrypted || access("/data/unencrypted", F_OK) == 0) {
+                        matched = DATA;
+                        break;
+                    }
+                }
+                [[fallthrough]];
+            case DATA:
                 continue;
-            } else {
+        }
-                new_matched = DATA;
-            }
-        } else if (info.target == "/metadata" && matched < METADATA) {
-            new_matched = METADATA;
-        } else if ((info.target == "/persist" || info.target == "/mnt/vendor/persist") &&
-                   matched < PERSIST) {
-            new_matched = PERSIST;
-        } else continue;
 
         if (mount) {
             preinit_dir = resolve_preinit_dir(info.target.data());
         }
-        rules_dev = info.device;
+        preinit_source = info.source;
-        matched = new_matched;
     }
 
     if (!preinit_dir.empty()) {
@@ -163,8 +184,7 @@ dev_t find_preinit_device() {
         mkdirs(mirror_dir.data(), 0700);
         xmount(preinit_dir.data(), mirror_dir.data(), nullptr, MS_BIND, nullptr);
     }
-
+    return preinit_source.empty() ? "" : basename(preinit_source.data());
-    return rules_dev;
 }
 
 static bool magisk_env() {

native/src/core/core.hpp

@@ -6,7 +6,7 @@
 extern bool RECOVERY_MODE;
 extern std::atomic<ino_t> pkg_xml_ino;
 
-dev_t find_preinit_device();
+std::string find_preinit_device();
 void unlock_blocks();
 void reboot();
 void start_log_daemon();

native/src/core/magisk.cpp

@@ -1,5 +1,4 @@
 #include <sys/mount.h>
-#include <sys/sysmacros.h>
 #include <libgen.h>
 
 #include <base.hpp>
@@ -134,9 +133,14 @@ int magisk_main(int argc, char *argv[]) {
     } else if (argc >= 3 && argv[1] == "--install-module"sv) {
         install_module(argv[2]);
     } else if (argv[1] == "--preinit-device"sv) {
-        auto dev = find_preinit_device();
+        set_log_level_state(LogLevel::Warn, false);
-        if (dev) printf("%u:%u\n", major(dev), minor(dev));
+        auto name = find_preinit_device();
-        return dev ? 0 : 1;
+        LOGD("preinit device: %s\n", name.data());
+        if (!name.empty())  {
+            printf("%s\n", name.data());
+            return 0;
+        }
+        return 1;
     }
 #if 0
     /* Entry point for testing stuffs */

native/src/init/init.hpp

@@ -57,7 +57,7 @@ public:
 
 class MagiskInit : public BaseInit {
 private:
-    dev_t preinit_dev = 0;
+    std::string preinit_dev;
 
     void parse_config_file();
     void patch_sepolicy(const char *in, const char *out);

native/src/init/mount.cpp

@@ -17,12 +17,14 @@ struct devinfo {
     char devname[32];
     char partname[32];
     char dmname[32];
+    char devpath[PATH_MAX];
 };
 
 static vector<devinfo> dev_list;
 
 static void parse_device(devinfo *dev, const char *uevent) {
     dev->partname[0] = '\0';
+    dev->devpath[0] = '\0';
     parse_prop_file(uevent, [=](string_view key, string_view value) -> bool {
         if (key == "MAJOR")
             dev->major = parse_int(value.data());
@@ -38,7 +40,7 @@ static void parse_device(devinfo *dev, const char *uevent) {
 }
 
 static void collect_devices() {
-    char path[128];
+    char path[PATH_MAX];
     devinfo dev{};
     if (auto dir = xopen_dir("/sys/dev/block"); dir) {
         for (dirent *entry; (entry = readdir(dir.get()));) {
@@ -51,6 +53,8 @@ static void collect_devices() {
                 auto name = rtrim(full_read(path));
                 strcpy(dev.dmname, name.data());
             }
+            sprintf(path, "/sys/dev/block/%s", entry->d_name);
+            xrealpath(path, dev.devpath, sizeof(dev.devpath));
             dev_list.push_back(dev);
         }
     }
@@ -61,7 +65,7 @@ static struct {
     char block_dev[64];
 } blk_info;
 
-static int64_t setup_block() {
+static dev_t setup_block() {
     if (dev_list.empty())
         collect_devices();
 
@@ -71,6 +75,10 @@ static int64_t setup_block() {
                 LOGD("Setup %s: [%s] (%d, %d)\n", dev.partname, dev.devname, dev.major, dev.minor);
             else if (strcasecmp(dev.dmname, blk_info.partname) == 0)
                 LOGD("Setup %s: [%s] (%d, %d)\n", dev.dmname, dev.devname, dev.major, dev.minor);
+            else if (strcasecmp(dev.devname, blk_info.partname) == 0)
+                LOGD("Setup %s: [%s] (%d, %d)\n", dev.devname, dev.devname, dev.major, dev.minor);
+            else if (std::string_view(dev.devpath).ends_with("/"s + blk_info.partname))
+                LOGD("Setup %s: [%s] (%d, %d)\n", dev.devpath, dev.devname, dev.major, dev.minor);
             else
                 continue;
 
@@ -85,7 +93,7 @@ static int64_t setup_block() {
     }
 
     // The requested partname does not exist
-    return -1;
+    return 0;
 }
 
 static void switch_root(const string &path) {
@@ -113,15 +121,20 @@ static void switch_root(const string &path) {
 
 #define PREINITMNT MIRRDIR "/preinit"
 
-static void mount_preinit_dir(string path, dev_t preinit_dev) {
+static void mount_preinit_dir(string path, string preinit_dev) {
-    if (!preinit_dev) return;
+    if (preinit_dev.empty()) return;
-    xmknod(PREINITDEV, S_IFBLK | 0600, preinit_dev);
+    strcpy(blk_info.partname, preinit_dev.data());
+    strcpy(blk_info.block_dev, PREINITDEV);
+    auto dev = setup_block();
+    if (dev == 0) {
+        LOGE("Cannot find preinit %s, abort!\n", preinit_dev.data());
+        return;
+    }
     xmkdir(PREINITMNT, 0);
-
     bool mounted = false;
     // First, find if it is already mounted
     for (auto &info : parse_mount_info("self")) {
-        if (info.root == "/" && info.device == preinit_dev) {
+        if (info.root == "/" && info.device == dev) {
             // Already mounted, just bind mount
             xmount(info.target.data(), PREINITMNT, nullptr, MS_BIND, nullptr);
             mounted = true;
@@ -147,7 +160,7 @@ static void mount_preinit_dir(string path, dev_t preinit_dev) {
         }
         xumount2(PREINITMNT, MNT_DETACH);
     } else {
-        PLOGE("Failed to mount rules %u:%u", major(preinit_dev), minor(preinit_dev));
+        PLOGE("Failed to mount preinit %s\n", preinit_dev.data());
         unlink(PREINITDEV);
     }
 }
@@ -164,18 +177,18 @@ bool LegacySARInit::mount_system_root() {
         // Try legacy SAR dm-verity
         strcpy(blk_info.partname, "vroot");
         auto dev = setup_block();
-        if (dev >= 0)
+        if (dev > 0)
             goto mount_root;
 
         // Try NVIDIA naming scheme
         strcpy(blk_info.partname, "APP");
         dev = setup_block();
-        if (dev >= 0)
+        if (dev > 0)
             goto mount_root;
 
         sprintf(blk_info.partname, "system%s", config->slot);
         dev = setup_block();
-        if (dev >= 0)
+        if (dev > 0)
             goto mount_root;
 
         // Poll forever if rootwait was given in cmdline

native/src/init/rootdir.cpp

@@ -183,18 +183,13 @@ static void extract_files(bool sbin) {
 }
 
 void MagiskInit::parse_config_file() {
-    dev_t dev = 0;
+    parse_prop_file("/data/.backup/.magisk", [this](auto key, auto value) -> bool {
-    parse_prop_file("/data/.backup/.magisk", [&dev](auto key, auto value) -> bool {
         if (key == "PREINITDEVICE") {
-            unsigned int dev_major = 0;
+            preinit_dev = value;
-            unsigned int dev_minor = 0;
-            sscanf(value.data(), "%u:%u", &dev_major, &dev_minor);
-            dev = makedev(dev_major, dev_minor);
             return false;
         }
         return true;
     });
-    preinit_dev = dev;
 }
 
 #define ROOTMIR     MIRRDIR "/system_root"