commit 37ba125205023b3b6e80ed684ca4d282224c66dc
author Jeff Sharkey <jsharkey@android.com> Fri Jan 19 10:55:18 2018 +0900
committer Jeff Sharkey <jsharkey@android.com> Fri Jan 19 11:58:43 2018 +0900
tree 40379acd9ac05c0bbdd4d498eeb7cb5bb87c3b64
parent a8b6225578b92af9f4b1e6852122c2377f7fe71d

Add basic exFAT support.

Several partners have been requesting exFAT support.  Android doesn't
natively support exFAT, but we're at least willing to try mounting an
exFAT filesystem if we detect the Linux kernel supports it, and if
helper binaries are present.

This CL is simple scaffolding, and it provides no actual
implementation of exFAT.

Test: builds, boots
Bug: 67822822
Change-Id: Id4f8ec3967b32de6e1c0e3c4b47fe6e43a6291ab

model/PublicVolume.cpp

diff --git a/model/PublicVolume.cpp b/model/PublicVolume.cpp
index 98c897f..efdb687 100644
--- a/model/PublicVolume.cpp
+++ b/model/PublicVolume.cpp
@@ -14,10 +14,11 @@
  * limitations under the License.
  */
 
-#include "fs/Vfat.h"
 #include "PublicVolume.h"
 #include "Utils.h"
 #include "VolumeManager.h"
+#include "fs/Exfat.h"
+#include "fs/Vfat.h"
 
 #include <android-base/stringprintf.h>
 #include <android-base/logging.h>
@@ -93,19 +94,23 @@
 }
 
 status_t PublicVolume::doMount() {
-    // TODO: expand to support mounting other filesystems
     readMetadata();
 
-    if (mFsType != "vfat") {
+    if (mFsType == "vfat" && vfat::IsSupported()) {
+        if (vfat::Check(mDevPath)) {
+            LOG(ERROR) << getId() << " failed filesystem check";
+            return -EIO;
+        }
+    } else if (mFsType == "exfat" && exfat::IsSupported()) {
+        if (exfat::Check(mDevPath)) {
+            LOG(ERROR) << getId() << " failed filesystem check";
+            return -EIO;
+        }
+    } else {
         LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
         return -EIO;
     }
 
-    if (vfat::Check(mDevPath)) {
-        LOG(ERROR) << getId() << " failed filesystem check";
-        return -EIO;
-    }
-
     // Use UUID as stable name, if available
     std::string stableName = getId();
     if (!mFsUuid.empty()) {
@@ -130,10 +135,17 @@
         return -errno;
     }
 
-    if (vfat::Mount(mDevPath, mRawPath, false, false, false,
-            AID_MEDIA_RW, AID_MEDIA_RW, 0007, true)) {
-        PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
-        return -EIO;
+    if (mFsType == "vfat") {
+        if (vfat::Mount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW, AID_MEDIA_RW, 0007,
+                        true)) {
+            PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
+            return -EIO;
+        }
+    } else if (mFsType == "exfat") {
+        if (exfat::Mount(mDevPath, mRawPath, AID_MEDIA_RW, AID_MEDIA_RW, 0007)) {
+            PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
+            return -EIO;
+        }
     }
 
     if (getMountFlags() & MountFlags::kPrimary) {
@@ -238,7 +250,7 @@
 }
 
 status_t PublicVolume::doFormat(const std::string& fsType) {
-    if (fsType == "vfat" || fsType == "auto") {
+    if ((fsType == "vfat" || fsType == "auto") && vfat::IsSupported()) {
         if (WipeBlockDevice(mDevPath) != OK) {
             LOG(WARNING) << getId() << " failed to wipe";
         }
@@ -246,6 +258,14 @@
             LOG(ERROR) << getId() << " failed to format";
             return -errno;
         }
+    } else if ((fsType == "exfat" || fsType == "auto") && exfat::IsSupported()) {
+        if (WipeBlockDevice(mDevPath) != OK) {
+            LOG(WARNING) << getId() << " failed to wipe";
+        }
+        if (exfat::Format(mDevPath)) {
+            LOG(ERROR) << getId() << " failed to format";
+            return -errno;
+        }
     } else {
         LOG(ERROR) << "Unsupported filesystem " << fsType;
         return -EINVAL;