vold: add coldboot back and make sure it won't block booting

coldboot is needed when device rebooted with USB device attched
so Vold netlink won't miss the information.
This CL added back coldboot and moved down so that it won't block
vold cl and ccl threads.

Bug: 36007238
Test: reboot marlin with flash drive attached and flash drive is recognized
Change-Id: Ie39f348e97a8500515e394e386541289a91b2425

1 files changed, 49 insertions, 0 deletions

diff --git a/main.cpp b/main.cpp
index 4810d43..6754b0a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -36,9 +36,11 @@
 #include <sys/types.h>
 #include <getopt.h>
 #include <fcntl.h>
+#include <dirent.h>
 #include <fs_mgr.h>
 
 static int process_config(VolumeManager *vm, bool* has_adoptable);
+static void coldboot(const char *path);
 static void parse_args(int argc, char** argv);
 
 struct fstab *fstab;
@@ -132,6 +134,10 @@ int main(int argc, char** argv) {
     // a deadlock between vold and init (see b/34278978 for details)
     property_set("vold.has_adoptable", has_adoptable ? "1" : "0");
 
+    // Do coldboot here so it won't block booting,
+    // also the cold boot is needed in case we have flash drive
+    // connected before Vold launched
+    coldboot("/sys/block");
     // Eventually we'll become the monitoring thread
     while(1) {
         pause();
@@ -165,6 +171,49 @@ static void parse_args(int argc, char** argv) {
     CHECK(android::vold::sFsckUntrustedContext != nullptr);
 }
 
+static void do_coldboot(DIR *d, int lvl) {
+    struct dirent *de;
+    int dfd, fd;
+
+    dfd = dirfd(d);
+
+    fd = openat(dfd, "uevent", O_WRONLY | O_CLOEXEC);
+    if(fd >= 0) {
+        write(fd, "add\n", 4);
+        close(fd);
+    }
+
+    while((de = readdir(d))) {
+        DIR *d2;
+
+        if (de->d_name[0] == '.')
+            continue;
+
+        if (de->d_type != DT_DIR && lvl > 0)
+            continue;
+
+        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
+        if(fd < 0)
+            continue;
+
+        d2 = fdopendir(fd);
+        if(d2 == 0)
+            close(fd);
+        else {
+            do_coldboot(d2, lvl + 1);
+            closedir(d2);
+        }
+    }
+}
+
+static void coldboot(const char *path) {
+    DIR *d = opendir(path);
+    if(d) {
+        do_coldboot(d, 0);
+        closedir(d);
+    }
+}
+
 static int process_config(VolumeManager *vm, bool* has_adoptable) {
     std::string path(android::vold::DefaultFstabPath());
     fstab = fs_mgr_read_fstab(path.c_str());