Fixed bugs with ASEC filesystem.
Changed ext4 to be 4kb aligned, and fat to be 32kb aligned.
Fixed issue that could potentially cause unencrypted ext4
ASECS to overwrite the ASEC super block when filled.
Change-Id: I890426c82ac9cbc65add85a8e3f5063504193c31
Signed-off-by: Daniel Rosenberg <drosen@google.com>
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 2049706..9889653 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -54,6 +54,9 @@
#define MASS_STORAGE_FILE_PATH "/sys/class/android_usb/android0/f_mass_storage/lun/file"
+#define ROUND_UP_POWER_OF_2(number, po2) (((!!(number & ((1U << po2) - 1))) << po2)\
+ + (number & (~((1U << po2) - 1))))
+
VolumeManager *VolumeManager::sInstance = NULL;
VolumeManager *VolumeManager::Instance() {
@@ -332,13 +335,17 @@
/*
* Add some headroom
+ * This is likely off by a bit, and we may want to do something different for ext4
*/
unsigned fatSize = (((numSectors * 4) / 512) + 1) * 2;
unsigned numImgSectors = numSectors + fatSize + 2;
-
- if (numImgSectors % 63) {
- numImgSectors += (63 - (numImgSectors % 63));
- }
+ /*
+ * ext4 is aligned to 4kb. fat is aligned to 32kb. Sectors are 512b.
+ */
+ if (usingExt4)
+ numImgSectors = ROUND_UP_POWER_OF_2(numImgSectors, 3);
+ else
+ numImgSectors = ROUND_UP_POWER_OF_2(numImgSectors, 6);
// Add +1 for our superblock which is at the end
if (Loop::createImageFile(asecFileName, numImgSectors + 1)) {
@@ -433,7 +440,7 @@
}
if (usingExt4) {
- formatStatus = Ext4::format(dmDevice, mountPoint);
+ formatStatus = Ext4::format(dmDevice, numImgSectors, mountPoint);
} else {
formatStatus = Fat::format(dmDevice, numImgSectors, 0);
}