init: Add wait command and mount wait flag

Change-Id: I6b4c10f8f246095a7fb7342388ec4f6ff97d5733

5 files changed, 36 insertions, 3 deletions

diff --git a/init/builtins.c b/init/builtins.c
index 1c839cd3..00eab832 100644
--- a/init/builtins.c
+++ b/init/builtins.c
@@ -277,6 +277,7 @@ int do_mount(int nargs, char **args)
     char *options = NULL;
     unsigned flags = 0;
     int n, i;
+    int wait = 0;
 
     for (n = 4; n < nargs; n++) {
         for (i = 0; mount_flags[i].name; i++) {
@@ -286,9 +287,13 @@ int do_mount(int nargs, char **args)
             }
         }
 
-        /* if our last argument isn't a flag, wolf it up as an option string */
-        if (n + 1 == nargs && !mount_flags[i].name)
-            options = args[n];
+        if (!mount_flags[i].name) {
+            if (!strcmp(args[n], "wait"))
+                wait = 1;
+            /* if our last argument isn't a flag, wolf it up as an option string */
+            else if (n + 1 == nargs)
+                options = args[n];
+        }
     }
 
     system = args[1];
@@ -303,6 +308,8 @@ int do_mount(int nargs, char **args)
 
         sprintf(tmp, "/dev/block/mtdblock%d", n);
 
+        if (wait)
+            wait_for_file(tmp, COMMAND_RETRY_TIMEOUT);
         if (mount(tmp, target, system, flags, options) < 0) {
             return -1;
         }
@@ -349,6 +356,8 @@ int do_mount(int nargs, char **args)
         ERROR("out of loopback devices");
         return -1;
     } else {
+        if (wait)
+            wait_for_file(source, COMMAND_RETRY_TIMEOUT);
         if (mount(source, target, system, flags, options) < 0) {
             return -1;
         }
@@ -574,3 +583,11 @@ int do_device(int nargs, char **args) {
                           decode_uid(args[4]), prefix);
     return 0;
 }
+
+int do_wait(int nargs, char **args)
+{
+    if (nargs == 2) {
+        return wait_for_file(args[1], COMMAND_RETRY_TIMEOUT);
+    }
+    return -1;
+}
diff --git a/init/keywords.h b/init/keywords.h
index 254c7855..1f4a77d0 100644
--- a/init/keywords.h
+++ b/init/keywords.h
@@ -28,6 +28,7 @@ int do_chown(int nargs, char **args);
 int do_chmod(int nargs, char **args);
 int do_loglevel(int nargs, char **args);
 int do_device(int nargs, char **args);
+int do_wait(int nargs, char **args);
 #define __MAKE_KEYWORD_ENUM__
 #define KEYWORD(symbol, flags, nargs, func) K_##symbol,
 enum {
@@ -69,6 +70,7 @@ enum {
     KEYWORD(symlink,     COMMAND, 1, do_symlink)
     KEYWORD(sysclktz,    COMMAND, 1, do_sysclktz)
     KEYWORD(user,        OPTION,  0, 0)
+    KEYWORD(wait,        COMMAND, 1, do_wait)
     KEYWORD(write,       COMMAND, 2, do_write)
     KEYWORD(copy,        COMMAND, 2, do_copy)
     KEYWORD(chown,       COMMAND, 2, do_chown)
diff --git a/init/parser.c b/init/parser.c
index b085da87..d5c044d9 100644
--- a/init/parser.c
+++ b/init/parser.c
@@ -204,6 +204,7 @@ int lookup_keyword(const char *s)
         break;
     case 'w':
         if (!strcmp(s, "rite")) return K_write;
+        if (!strcmp(s, "ait")) return K_wait;
         break;
     }
     return K_UNKNOWN;
diff --git a/init/util.c b/init/util.c
index b955e7e7..761c51b3 100644
--- a/init/util.c
+++ b/init/util.c
@@ -378,3 +378,15 @@ void remove_link(const char *oldpath, const char *newpath)
     if (!strcmp(path, oldpath))
         unlink(newpath);
 }
+
+int wait_for_file(const char *filename, int timeout)
+{
+    struct stat info;
+    time_t timeout_time = gettime() + timeout;
+    int ret = -1;
+
+    while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0))
+        usleep(10000);
+
+    return ret;
+}
diff --git a/init/util.h b/init/util.h
index 3dadfb93..bf7928d3 100644
--- a/init/util.h
+++ b/init/util.h
@@ -28,4 +28,5 @@ int mkdir_recursive(const char *pathname, mode_t mode);
 void sanitize(char *p);
 void make_link(const char *oldpath, const char *newpath);
 void remove_link(const char *oldpath, const char *newpath);
+int wait_for_file(const char *filename, int timeout);
 #endif