commit 4cff06d45faa4cf62f471f56550006e5f0a2d7db
author Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Wed May 23 18:59:48 2018 +0200
committer John Eckerdal <john.eckerdal@sony.com> Mon Sep 24 14:28:24 2018 +0200
tree 7e6c96b19716dbb1b8135ddf8e88ceceae00a94c
parent 625dc787c629cd04e30328a9b1cf4a8e7d6210bc

Use exFAT for SDXC cards

When both VFAT and exFAT are supported VFAT will only be used to
format card. Use exFAT for cards larger than 32GB per SDXC standard.

Test: build, manual, mount exFAT volume
Bug: 80202067
Change-Id: If504f9685256a669c5801a69d69d5a214ad27455

model/PublicVolume.cpp

diff --git a/model/PublicVolume.cpp b/model/PublicVolume.cpp
index 7420c79..fc1c9e2 100644
--- a/model/PublicVolume.cpp
+++ b/model/PublicVolume.cpp
@@ -246,28 +246,53 @@
 }
 
 status_t PublicVolume::doFormat(const std::string& fsType) {
-    if ((fsType == "vfat" || fsType == "auto") && vfat::IsSupported()) {
-        if (WipeBlockDevice(mDevPath) != OK) {
-            LOG(WARNING) << getId() << " failed to wipe";
+    bool useVfat = vfat::IsSupported();
+    bool useExfat = exfat::IsSupported();
+    status_t res = OK;
+
+    // Resolve the target filesystem type
+    if (fsType == "auto" && useVfat && useExfat) {
+        uint64_t size = 0;
+
+        res = GetBlockDevSize(mDevPath, &size);
+        if (res != OK) {
+            LOG(ERROR) << "Couldn't get device size " << mDevPath;
+            return res;
         }
-        if (vfat::Format(mDevPath, 0)) {
-            LOG(ERROR) << getId() << " failed to format";
-            return -errno;
+
+        // If both vfat & exfat are supported use exfat for SDXC (>~32GiB) cards
+        if (size > 32896LL * 1024 * 1024) {
+            useVfat = false;
+        } else {
+            useExfat = false;
         }
-    } 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 {
+    } else if (fsType == "vfat") {
+        useExfat = false;
+    } else if (fsType == "exfat") {
+        useVfat = false;
+    }
+
+    if (!useVfat && !useExfat) {
         LOG(ERROR) << "Unsupported filesystem " << fsType;
         return -EINVAL;
     }
 
-    return OK;
+    if (WipeBlockDevice(mDevPath) != OK) {
+        LOG(WARNING) << getId() << " failed to wipe";
+    }
+
+    if (useVfat) {
+        res = vfat::Format(mDevPath, 0);
+    } else if (useExfat) {
+        res = exfat::Format(mDevPath);
+    }
+
+    if (res != OK) {
+        LOG(ERROR) << getId() << " failed to format";
+        res = -errno;
+    }
+
+    return res;
 }
 
 }  // namespace vold