vold: use blkid to detect filesystem type

In preparation for handling ext4 partitions via vold and fuse.

Change-Id: Ibaccded63a7a293ad53f16afb80448ddd493554c

2 files changed, 63 insertions, 31 deletions

diff --git a/Android.mk b/Android.mk
index 5335cf6..79ea6a7 100644
--- a/Android.mk
+++ b/Android.mk
@@ -23,14 +23,16 @@ common_src_files := \
 common_c_includes := \
 	$(KERNEL_HEADERS) \
 	system/extras/ext4_utils \
-	external/openssl/include
+	external/openssl/include \
+	external/e2fsprogs/lib
 
 common_shared_libraries := \
 	libsysutils \
 	libcutils \
 	libdiskconfig \
 	libhardware_legacy \
-	libcrypto
+	libcrypto \
+	libext2_blkid
 
 include $(CLEAR_VARS)
 
@@ -54,7 +56,8 @@ LOCAL_C_INCLUDES := $(common_c_includes)
 
 LOCAL_SHARED_LIBRARIES := $(common_shared_libraries)
 
-LOCAL_STATIC_LIBRARIES := libfs_mgr
+LOCAL_STATIC_LIBRARIES := \
+	libfs_mgr
 
 LOCAL_MODULE_TAGS := eng tests
 
@@ -94,7 +97,8 @@ endif
 
 LOCAL_SHARED_LIBRARIES := $(common_shared_libraries)
 
-LOCAL_STATIC_LIBRARIES := libfs_mgr
+LOCAL_STATIC_LIBRARIES := \
+	libfs_mgr
 
 include $(BUILD_EXECUTABLE)
 
diff --git a/Volume.cpp b/Volume.cpp
index 437bfa0..422b566 100644
--- a/Volume.cpp
+++ b/Volume.cpp
@@ -36,6 +36,8 @@
 
 #include <private/android_filesystem_config.h>
 
+#include <blkid/blkid.h>
+
 #define LOG_TAG "Vold"
 
 #include <cutils/log.h>
@@ -51,7 +53,6 @@
 extern "C" void dos_partition_dec(void const *pp, struct dos_partition *d);
 extern "C" void dos_partition_enc(void *pp, struct dos_partition *d);
 
-
 /*
  * Secure directory - stuff that only root can see
  */
@@ -185,6 +186,22 @@ dev_t Volume::getShareDevice() {
     return getDiskDevice();
 }
 
+char *getFsType(const char * devicePath) {
+    char *fstype = NULL;
+
+    SLOGD("Trying to get filesystem type for %s \n", devicePath);
+
+    fstype = blkid_get_tag_value(NULL, "TYPE", devicePath);
+    if (fstype) {
+        SLOGD("Found %s filesystem on %s\n", fstype, devicePath);
+    } else {
+        SLOGE("None or unknown filesystem on %s\n", devicePath);
+        return NULL;
+    }
+
+    return fstype;
+}
+
 void Volume::handleVolumeShared() {
 }
 
@@ -432,6 +449,7 @@ int Volume::mountVol() {
 
     for (i = 0; i < n; i++) {
         char devicePath[255];
+        char *fstype = NULL;
 
         sprintf(devicePath, "/dev/block/vold/%d:%d", MAJOR(deviceNodes[i]),
                 MINOR(deviceNodes[i]));
@@ -441,20 +459,6 @@ int Volume::mountVol() {
         errno = 0;
         setState(Volume::State_Checking);
 
-        bool isFatFs = true;
-        if (Fat::check(devicePath)) {
-            if (errno == ENODATA) {
-                SLOGW("%s does not contain a FAT filesystem\n", devicePath);
-                isFatFs = false;
-            } else {
-                errno = EIO;
-                /* Badness - abort the mount */
-                SLOGE("%s failed FS checks (%s)", devicePath, strerror(errno));
-                setState(Volume::State_Idle);
-                return -1;
-            }
-        }
-
         /*
          * Mount the device on our internal staging mountpoint so we can
          * muck with it before exposing it to non priviledged users.
@@ -466,20 +470,44 @@ int Volume::mountVol() {
         // prevented users from writing to it. We don't want that.
         gid = AID_SDCARD_RW;
 
-        if (isFatFs) {
-            if (Fat::doMount(devicePath, "/mnt/secure/staging", false, false, false,
-                    AID_SYSTEM, gid, 0702, true)) {
-                SLOGE("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno));
-                continue;
-            }
-        } else {
-            if (Ntfs::doMount(devicePath, "/mnt/secure/staging", false, false, false,
-                    AID_SYSTEM, gid, 0702, true)) {
-                SLOGE("%s failed to mount via NTFS (%s)\n", devicePath, strerror(errno));
-                continue;
+        fstype = getFsType((const char *)devicePath);
+
+        if (fstype != NULL) {
+            if (strcmp(fstype, "vfat") == 0) {
+
+                if (Fat::check(devicePath)) {
+                    errno = EIO;
+                    /* Badness - abort the mount */
+                    SLOGE("%s failed FS checks (%s)", devicePath, strerror(errno));
+                    setState(Volume::State_Idle);
+                    free(fstype);
+                    return -1;
+                }
+
+                if (Fat::doMount(devicePath, "/mnt/secure/staging", false, false, false,
+                        AID_SYSTEM, gid, 0702, true)) {
+                    SLOGE("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno));
+                    continue;
+                }
+
+            } else if (strcmp(fstype, "ntfs") == 0) {
+
+                if (Ntfs::doMount(devicePath, "/mnt/secure/staging", false, false, false,
+                        AID_SYSTEM, gid, 0702, true)) {
+                    SLOGE("%s failed to mount via NTFS (%s)\n", devicePath, strerror(errno));
+                    continue;
+                }
+
+            } else {
+                // Unsupported filesystem
+                errno = ENODATA;
+                setState(Volume::State_Idle);
+                free(fstype);
+                return -1;
             }
-        }
 
+            free(fstype);
+        }
         SLOGI("Device %s, target %s mounted @ /mnt/secure/staging", devicePath, getMountpoint());
 
         protectFromAutorunStupidity();