recovery: datamedia support

Change-Id: I4cef82973a15111bee92cd7c81f0e1db8d211991

1 files changed, 86 insertions, 1 deletions

diff --git a/roots.cpp b/roots.cpp
index b4860d7..fda8f61 100644
--- a/roots.cpp
+++ b/roots.cpp
@@ -309,7 +309,60 @@ static int exec_cmd(const char* path, char* const argv[]) {
     return WEXITSTATUS(status);
 }
 
+static int rmtree_except(const char* path, const char* except)
+{
+    char pathbuf[PATH_MAX];
+    int rc = 0;
+    DIR* dp = opendir(path);
+    if (dp == NULL) {
+        return -1;
+    }
+    struct dirent* de;
+    while ((de = readdir(dp)) != NULL) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+        if (except && !strcmp(de->d_name, except))
+            continue;
+        struct stat st;
+        snprintf(pathbuf, sizeof(pathbuf), "%s/%s", path, de->d_name);
+        rc = lstat(pathbuf, &st);
+        if (rc != 0) {
+            LOGE("Failed to stat %s\n", pathbuf);
+            break;
+        }
+        if (S_ISDIR(st.st_mode)) {
+            rc = rmtree_except(pathbuf, NULL);
+            if (rc != 0)
+                break;
+            rc = rmdir(pathbuf);
+        }
+        else {
+            rc = unlink(pathbuf);
+        }
+        if (rc != 0) {
+            LOGI("Failed to remove %s: %s\n", pathbuf, strerror(errno));
+            break;
+        }
+    }
+    closedir(dp);
+    return rc;
+}
+
 int format_volume(const char* volume) {
+    if (strcmp(volume, "media") == 0) {
+        if (!vdc->isEmulatedStorage()) {
+            return 0;
+        }
+        if (ensure_path_mounted("/data") != 0) {
+            LOGE("format_volume failed to mount /data\n");
+            return -1;
+        }
+        int rc = 0;
+        rc = rmtree_except("/data/media", NULL);
+        ensure_path_unmounted("/data");
+        return rc;
+    }
+
     Volume* v = volume_for_path(volume);
     if (v == NULL) {
         LOGE("unknown volume \"%s\"\n", volume);
@@ -325,6 +378,38 @@ int format_volume(const char* volume) {
         return -1;
     }
 
+    if (strcmp(volume, "/data") == 0 && vdc->isEmulatedStorage()) {
+        if (ensure_path_mounted("/data") == 0) {
+            // Preserve .layout_version to avoid "nesting bug"
+            LOGI("Preserving layout version\n");
+            unsigned char layout_buf[256];
+            ssize_t layout_buflen = -1;
+            int fd;
+            fd = open("/data/.layout_version", O_RDONLY);
+            if (fd != -1) {
+                layout_buflen = read(fd, layout_buf, sizeof(layout_buf));
+                close(fd);
+            }
+
+            int rc = rmtree_except("/data", "media");
+
+            // Restore .layout_version
+            if (layout_buflen > 0) {
+                LOGI("Restoring layout version\n");
+                fd = open("/data/.layout_version", O_WRONLY | O_CREAT | O_EXCL, 0600);
+                if (fd != -1) {
+                    write(fd, layout_buf, layout_buflen);
+                    close(fd);
+                }
+            }
+
+            ensure_path_unmounted(volume);
+
+            return rc;
+        }
+        LOGE("format_volume failed to mount /data, formatting instead\n");
+    }
+
     if (ensure_path_unmounted(volume) != 0) {
         LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
         return -1;
@@ -431,7 +516,7 @@ int setup_install_mounts() {
             // datamedia and anything managed by vold must be unmounted
             // with the detach flag to ensure that FUSE works.
             bool detach = false;
-            if (is_data_media() && strcmp(v->mount_point, "/data") == 0) {
+            if (vdc->isEmulatedStorage() && strcmp(v->mount_point, "/data") == 0) {
                 detach = true;
             }
             if (ensure_volume_unmounted(v, detach) != 0) {