commit 3d95d88b14ce1272202a866296258dcd3a1a85ce
author Ryo Hashimoto <hashimoto@google.com> Wed Mar 14 19:24:47 2018 +0900
committer Ryo Hashimoto <hashimoto@google.com> Thu Mar 15 14:22:27 2018 +0900
tree c0614317be1afd2858b6982d41cce807f8b42d16
parent 84379567d3c7d9df0d05b9f02093b1548563450a

Stop using SO_SNDBUFFORCE

Use SO_SNDBUF which doesn't require CAP_NET_ADMIN instead.
Change the value of kFuseMaxWrite to 128KB.

In the kernel code, there is a constant FUSE_MAX_PAGES_PER_REQ which
limits the size of requests to 128KB.

Bug: 74725300
Test: atest android.os.storage.cts.StorageManagerTest

Change-Id: Ic3a8f1a7378d027a6c0ee054cedc2c9f4b7509ad

libappfuse/FuseBuffer.cc

diff --git a/libappfuse/FuseBuffer.cc b/libappfuse/FuseBuffer.cc
index 1eab46c..1915f22 100644
--- a/libappfuse/FuseBuffer.cc
+++ b/libappfuse/FuseBuffer.cc
@@ -149,8 +149,8 @@
     }
 
     constexpr int kMaxMessageSize = sizeof(FuseBuffer);
-    if (setsockopt(fds[0], SOL_SOCKET, SO_SNDBUFFORCE, &kMaxMessageSize, sizeof(int)) != 0 ||
-        setsockopt(fds[1], SOL_SOCKET, SO_SNDBUFFORCE, &kMaxMessageSize, sizeof(int)) != 0) {
+    if (setsockopt(fds[0], SOL_SOCKET, SO_SNDBUF, &kMaxMessageSize, sizeof(int)) != 0 ||
+        setsockopt(fds[1], SOL_SOCKET, SO_SNDBUF, &kMaxMessageSize, sizeof(int)) != 0) {
         PLOG(ERROR) << "Failed to update buffer size for socket";
         return false;
     }

libappfuse/include/libappfuse/FuseBuffer.h

diff --git a/libappfuse/include/libappfuse/FuseBuffer.h b/libappfuse/include/libappfuse/FuseBuffer.h
index 7a70bf3..3063815 100644
--- a/libappfuse/include/libappfuse/FuseBuffer.h
+++ b/libappfuse/include/libappfuse/FuseBuffer.h
@@ -25,7 +25,7 @@
 
 // The numbers came from sdcard.c.
 // Maximum number of bytes to write/read in one request/one reply.
-constexpr size_t kFuseMaxWrite = 256 * 1024;
+constexpr size_t kFuseMaxWrite = 128 * 1024;
 constexpr size_t kFuseMaxRead = 128 * 1024;
 constexpr int32_t kFuseSuccess = 0;