commit 13449cd71464c3a644109c469a77bd7fd56c8af8
author Sami Tolvanen <samitolvanen@google.com> Fri Jan 02 13:30:50 2015 +0000
committer Sami Tolvanen <samitolvanen@google.com> Mon Jan 05 20:31:25 2015 +0000
tree 203af11d7f9c1a2f81800767a738ae7fc14208df
parent 69159ba0b70178a24e6f592dfb9d903629c23a09

Fix disable-verity when the underlying block device is RO

If verity is enabled and the underlying block device is marked
read-only, disable-verity fails. We cannot use the existing code
for enable-verity to make the device writable as the device in
/proc/mounts will be the verity device instead of the underlying
device we want to change. This change makes the correct device
writable when altering verity state.

Change-Id: I423ee50fb34d78cff2fe843318b9081c03c5142d

adb/remount_service.c

diff --git a/adb/remount_service.c b/adb/remount_service.c
index 9746f9a..2479f88 100644
--- a/adb/remount_service.c
+++ b/adb/remount_service.c
@@ -79,14 +79,12 @@
     return false;
 }
 
-static int make_block_device_writable(const char* dir)
+int make_block_device_writable(const char* dev)
 {
-    char *dev = 0;
     int fd = -1;
     int OFF = 0;
     int rc = -1;
 
-    dev = find_mount(dir);
     if (!dev)
         goto errout;
 
@@ -104,36 +102,27 @@
     if (fd >= 0) {
         adb_close(fd);
     }
-
-    if (dev) {
-        free(dev);
-    }
     return rc;
 }
 
 /* Init mounts /system as read only, remount to enable writes. */
 static int remount(const char* dir, int* dir_ro)
 {
-    char *dev;
-
-    if (dir_ro == 0) {
-        return 0;
-    }
-
-    if (make_block_device_writable(dir)) {
-        return -1;
-    }
+    char *dev = 0;
+    int rc = -1;
 
     dev = find_mount(dir);
 
-    if (!dev)
-        return -1;
+    if (!dev || make_block_device_writable(dev)) {
+        goto errout;
+    }
 
-    *dir_ro = mount(dev, dir, "none", MS_REMOUNT, NULL);
+    rc = mount(dev, dir, "none", MS_REMOUNT, NULL);
+    *dir_ro = rc;
 
+errout:
     free(dev);
-
-    return *dir_ro;
+    return rc;
 }
 
 static void write_string(int fd, const char* str)
@@ -141,28 +130,6 @@
     writex(fd, str, strlen(str));
 }
 
-int make_system_and_vendor_block_devices_writable(int fd)
-{
-    char buffer[200];
-    if (make_block_device_writable("/system")) {
-        snprintf(buffer, sizeof(buffer),
-                 "Failed to make system block device writable %s\n",
-                 strerror(errno));
-        write_string(fd, buffer);
-        return -1;
-    }
-
-    if (hasVendorPartition() && make_block_device_writable("/vendor")) {
-        snprintf(buffer, sizeof(buffer),
-                 "Failed to make vendor block device writable: %s\n",
-                 strerror(errno));
-        write_string(fd, buffer);
-        return -1;
-    }
-
-    return 0;
-}
-
 void remount_service(int fd, void *cookie)
 {
     char buffer[200];