diff --git a/Fat.cpp b/Fat.cpp
index 6ac1f8a..018fbeb 100644
--- a/Fat.cpp
+++ b/Fat.cpp
@@ -227,28 +227,35 @@ int Fat::format(const char *fsPath, unsigned int numSectors, bool wipe) {
 }
 
 void Fat::wipe(const char *fsPath, unsigned int numSectors) {
-    int fd;
     unsigned long long range[2];
 
-    fd = open(fsPath, O_RDWR);
-    if (fd >= 0) {
-        if (numSectors == 0) {
-            numSectors = get_blkdev_size(fd);
-        }
-        if (numSectors == 0) {
-            SLOGE("Fat wipe failed to determine size of %s", fsPath);
+    int fd = open(fsPath, O_RDWR);
+    if (fd == -1) {
+        SLOGE("Fat wipe failed to open device %s", fsPath);
+        return;
+    }
+
+    if (numSectors == 0) {
+        unsigned long nr_sec;
+        get_blkdev_size(fd, &nr_sec);
+        if (nr_sec > UINT32_MAX) {
+            SLOGE("Too many sectors for FAT: %ld", nr_sec);
             close(fd);
             return;
         }
-        range[0] = 0;
-        range[1] = (unsigned long long)numSectors * 512;
-        if (ioctl(fd, BLKDISCARD, &range) < 0) {
-            SLOGE("Fat wipe failed to discard blocks on %s", fsPath);
-        } else {
-            SLOGI("Fat wipe %d sectors on %s succeeded", numSectors, fsPath);
-        }
+        numSectors = nr_sec;
+    }
+    if (numSectors == 0) {
+        SLOGE("Fat wipe failed to determine size of %s", fsPath);
         close(fd);
+        return;
+    }
+    range[0] = 0;
+    range[1] = (unsigned long long)numSectors * 512;
+    if (ioctl(fd, BLKDISCARD, &range) < 0) {
+        SLOGE("Fat wipe failed to discard blocks on %s", fsPath);
     } else {
-        SLOGE("Fat wipe failed to open device %s", fsPath);
+        SLOGI("Fat wipe %d sectors on %s succeeded", numSectors, fsPath);
     }
+    close(fd);
 }
diff --git a/Loop.cpp b/Loop.cpp
index 1ed5bd0..b1e9f6a 100644
--- a/Loop.cpp
+++ b/Loop.cpp
@@ -35,6 +35,7 @@
 #include <sysutils/SocketClient.h>
 #include "Loop.h"
 #include "Asec.h"
+#include "VoldUtil.h"
 #include "sehandle.h"
 
 int Loop::dumpState(SocketClient *c) {
@@ -296,7 +297,7 @@ int Loop::resizeImageFile(const char *file, unsigned int numSectors) {
     return 0;
 }
 
-int Loop::lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned int *nr_sec) {
+int Loop::lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned long *nr_sec) {
     int fd;
     struct asec_superblock buffer;
 
@@ -306,7 +307,8 @@ int Loop::lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigne
         return -1;
     }
 
-    if (ioctl(fd, BLKGETSIZE, nr_sec)) {
+    get_blkdev_size(fd, nr_sec);
+    if (*nr_sec == 0) {
         SLOGE("Failed to get loop size (%s)", strerror(errno));
         destroyByDevice(loopDevice);
         close(fd);
diff --git a/Loop.h b/Loop.h
index 45e6115..f7c0392 100644
--- a/Loop.h
+++ b/Loop.h
@@ -27,7 +27,7 @@ public:
     static const int LOOP_MAX = 4096;
 public:
     static int lookupActive(const char *id, char *buffer, size_t len);
-    static int lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned int *nr_sec);
+    static int lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned long *nr_sec);
     static int create(const char *id, const char *loopFile, char *loopDeviceBuffer, size_t len);
     static int destroyByDevice(const char *loopDevice);
     static int destroyByFile(const char *loopFile);
diff --git a/VoldUtil.c b/VoldUtil.c
index b5f9946..e5bc912 100644
--- a/VoldUtil.c
+++ b/VoldUtil.c
@@ -17,13 +17,8 @@
 #include <sys/ioctl.h>
 #include <linux/fs.h>
 
-unsigned int get_blkdev_size(int fd)
-{
-  unsigned int nr_sec;
-
-  if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
-    nr_sec = 0;
+void get_blkdev_size(int fd, unsigned long* nr_sec) {
+  if ((ioctl(fd, BLKGETSIZE, nr_sec)) == -1) {
+    *nr_sec = 0;
   }
-
-  return nr_sec;
 }
diff --git a/VoldUtil.h b/VoldUtil.h
index 469489a..5738382 100644
--- a/VoldUtil.h
+++ b/VoldUtil.h
@@ -22,7 +22,7 @@
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
 __BEGIN_DECLS
-  unsigned int get_blkdev_size(int fd);
+void get_blkdev_size(int fd, unsigned long* nr_sec);
 __END_DECLS
 
 #endif
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 4c5bb58..d6907f2 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -52,6 +52,7 @@
 #include "Devmapper.h"
 #include "Process.h"
 #include "Asec.h"
+#include "VoldUtil.h"
 #include "cryptfs.h"
 
 #define MASS_STORAGE_FILE_PATH  "/sys/class/android_usb/android0/f_mass_storage/lun/file"
@@ -759,7 +760,7 @@ int VolumeManager::finalizeAsec(const char *id) {
         return -1;
     }
 
-    unsigned int nr_sec = 0;
+    unsigned long nr_sec = 0;
     struct asec_superblock sb;
 
     if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
@@ -822,7 +823,7 @@ int VolumeManager::fixupAsecPermissions(const char *id, gid_t gid, const char* f
         return -1;
     }
 
-    unsigned int nr_sec = 0;
+    unsigned long nr_sec = 0;
     struct asec_superblock sb;
 
     if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
@@ -1297,7 +1298,7 @@ int VolumeManager::mountAsec(const char *id, const char *key, int ownerUid, bool
     char dmDevice[255];
     bool cleanupDm = false;
 
-    unsigned int nr_sec = 0;
+    unsigned long nr_sec = 0;
     struct asec_superblock sb;
 
     if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
@@ -1403,7 +1404,7 @@ int VolumeManager::mountObb(const char *img, const char *key, int ownerGid) {
     char dmDevice[255];
     bool cleanupDm = false;
     int fd;
-    unsigned int nr_sec = 0;
+    unsigned long nr_sec = 0;
 
     if ((fd = open(loopDevice, O_RDWR)) < 0) {
         SLOGE("Failed to open loopdevice (%s)", strerror(errno));
@@ -1411,7 +1412,8 @@ int VolumeManager::mountObb(const char *img, const char *key, int ownerGid) {
         return -1;
     }
 
-    if (ioctl(fd, BLKGETSIZE, &nr_sec)) {
+    get_blkdev_size(fd, &nr_sec);
+    if (nr_sec == 0) {
         SLOGE("Failed to get loop size (%s)", strerror(errno));
         Loop::destroyByDevice(loopDevice);
         close(fd);
@@ -1420,7 +1422,7 @@ int VolumeManager::mountObb(const char *img, const char *key, int ownerGid) {
 
     close(fd);
 
-    if (setupDevMapperDevice(dmDevice, sizeof(loopDevice), loopDevice, img,key, idHash , nr_sec, &cleanupDm, mDebug)) {
+    if (setupDevMapperDevice(dmDevice, sizeof(loopDevice), loopDevice, img,key, idHash, nr_sec, &cleanupDm, mDebug)) {
         Loop::destroyByDevice(loopDevice);
         return -1;
     }
diff --git a/cryptfs.c b/cryptfs.c
index 735232d..bbd952b 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -417,7 +417,6 @@ static int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
   int fd;
   char key_loc[PROPERTY_VALUE_MAX];
   char real_blkdev[PROPERTY_VALUE_MAX];
-  unsigned int nr_sec;
   int rc = -1;
 
   if (!cached_data) {
@@ -429,7 +428,9 @@ static int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
         return -1;
       }
 
-      if ((nr_sec = get_blkdev_size(fd))) {
+      unsigned long nr_sec = 0;
+      get_blkdev_size(fd, &nr_sec);
+      if (nr_sec != 0) {
         /* If it's an encrypted Android partition, the last 16 Kbytes contain the
          * encryption info footer and key, and plenty of bytes to spare for future
          * growth.
@@ -1905,17 +1906,22 @@ int cryptfs_setup_volume(const char *label, int major, int minor,
     char real_blkdev[MAXPATHLEN], crypto_blkdev[MAXPATHLEN];
     struct crypt_mnt_ftr sd_crypt_ftr;
     struct stat statbuf;
-    unsigned int nr_sec;
-    int fd;
 
     sprintf(real_blkdev, "/dev/block/vold/%d:%d", major, minor);
 
     get_crypt_ftr_and_key(&sd_crypt_ftr);
 
     /* Update the fs_size field to be the size of the volume */
-    fd = open(real_blkdev, O_RDONLY);
-    nr_sec = get_blkdev_size(fd);
+    int fd = open(real_blkdev, O_RDONLY);
+    if (fd == -1) {
+        SLOGE("Cannot open volume %s\n", real_blkdev);
+        return -1;
+    }
+
+    unsigned long nr_sec = 0;
+    get_blkdev_size(fd, &nr_sec);
     close(fd);
+
     if (nr_sec == 0) {
         SLOGE("Cannot get size of volume %s\n", real_blkdev);
         return -1;
@@ -2931,9 +2937,8 @@ int cryptfs_enable_internal(char *howarg, int crypt_type, char *passwd,
 {
     int how = 0;
     char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN];
-    unsigned long nr_sec;
     unsigned char decrypted_master_key[KEY_LEN_BYTES];
-    int rc=-1, fd, i;
+    int rc=-1, i;
     struct crypt_mnt_ftr crypt_ftr;
     struct crypt_persist_data *pdata;
     char encrypted_state[PROPERTY_VALUE_MAX];
@@ -2982,8 +2987,14 @@ int cryptfs_enable_internal(char *howarg, int crypt_type, char *passwd,
     fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev));
 
     /* Get the size of the real block device */
-    fd = open(real_blkdev, O_RDONLY);
-    if ( (nr_sec = get_blkdev_size(fd)) == 0) {
+    int fd = open(real_blkdev, O_RDONLY);
+    if (fd == -1) {
+        SLOGE("Cannot open block device %s\n", real_blkdev);
+        goto error_unencrypted;
+    }
+    unsigned long nr_sec;
+    get_blkdev_size(fd, &nr_sec);
+    if (nr_sec == 0) {
         SLOGE("Cannot get size of block device %s\n", real_blkdev);
         goto error_unencrypted;
     }