Fix Android device issues related to filesystem/IO

- Use F_SETLK64 for fcntl to fix an issue where 32bit arm Android apps would get the wrong flag
- Add numerical magic numbers for missing file systems to Interop.UnixFileSystemTypes so they are correctly recognized
- Make ping test a bit more forgiving if the process returns a few milliseconds _before_ the timeout
- Disable System.IO.Net5Compat.Tests.csproj on Helix for non-Windows platforms like intended, we were still building it since we pass `/p:ArchiveTests=true` on CI

src/libraries/Common/src/Interop/Unix/System.Native/Interop.MountPoints.FormatInfo.cs

@@ -80,6 +80,7 @@ private static DriveType GetDriveType(string fileSystemName)
             // This list is based primarily on "man fs", "man mount", "mntent.h", "/proc/filesystems", coreutils "stat.c",
             // and "wiki.debian.org/FileSystem". It can be extended over time as we find additional file systems that should
             // be recognized as a particular drive type.
+            // Keep this in sync with the UnixFileSystemTypes enum in Interop.UnixFileSystemTypes.cs
             switch (fileSystemName)
             {
                 case "cddafs":

src/libraries/Common/src/Interop/Unix/System.Native/Interop.UnixFileSystemTypes.cs

@@ -28,6 +28,7 @@ internal enum UnixFileSystemTypes : long
             befs = 0x42465331,
             bdevfs = 0x62646576,
             bfs = 0x1BADFACE,
+            bpf_fs = 0xCAFE4A11,
             binfmt_misc = 0x42494E4D,
             bootfs = 0xA56D3FF9,
             btrfs = 0x9123683E,
@@ -53,6 +54,7 @@ internal enum UnixFileSystemTypes : long
             ext2 = 0xEF53,
             ext3 = 0xEF53,
             ext4 = 0xEF53,
+            f2fs = 0xF2F52010,
             fat = 0x4006,
             fd = 0xF00D1E,
             fhgfs = 0x19830326,
@@ -122,6 +124,7 @@ internal enum UnixFileSystemTypes : long
             sysv2 = 0x012FF7B6,
             sysv4 = 0x012FF7B5,
             tmpfs = 0x01021994,
+            tracefs = 0x74726163,
             ubifs = 0x24051905,
             udf = 0x15013346,
             ufs = 0x00011954,

src/libraries/Native/Unix/System.Native/pal_io.c

@@ -1560,13 +1560,21 @@ int32_t SystemNative_LockFileRegion(intptr_t fd, int64_t offset, int64_t length,
     struct flock lockArgs;
 #endif
 
+#if defined(TARGET_ANDROID) && defined(HAVE_FLOCK64)
+    // On Android, fcntl is always implemented by fcntl64 but before https://github.com/aosp-mirror/platform_bionic/commit/09e77f35ab8d291bf88302bb9673aaa518c6bcb0
+    // there was no remapping of F_SETLK to F_SETLK64 when _FILE_OFFSET_BITS=64 (which we set in eng/native/configurecompiler.cmake) so we need to always pass F_SETLK64
+    int command = F_SETLK64;
+#else
+    int command = F_SETLK;
+#endif
+
     lockArgs.l_type = unixLockType;
     lockArgs.l_whence = SEEK_SET;
     lockArgs.l_start = (off_t)offset;
     lockArgs.l_len = (off_t)length;
 
     int32_t ret;
-    while ((ret = fcntl (ToFileDescriptor(fd), F_SETLK, &lockArgs)) < 0 && errno == EINTR);
+    while ((ret = fcntl (ToFileDescriptor(fd), command, &lockArgs)) < 0 && errno == EINTR);
     return ret;
 }
 

src/libraries/System.IO/tests/Net5CompatTests/System.IO.Net5Compat.Tests.csproj

@@ -6,6 +6,7 @@
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
     <!-- Windows is currently the only OS for which we provide a new strategy, so we test the Net5Compat only for Windows -->
     <TargetFrameworks>$(NetCoreAppCurrent)-windows</TargetFrameworks>
+    <IgnoreForCI Condition="'$(TargetOS)' != 'windows'">true</IgnoreForCI>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\**\*.cs" />

src/libraries/System.Net.Ping/tests/FunctionalTests/UnixPingUtilityTests.cs

@@ -37,8 +37,8 @@ public static void TimeoutIsRespected(int timeout)
             p.Start();
             p.WaitForExit();
 
-            //ensure that the process takes longer than or equal to 'timeout'
-            Assert.True(stopWatch.ElapsedMilliseconds >= timeout);
+            //ensure that the process takes longer than or within 10ms of 'timeout', with a 5s maximum
+            Assert.InRange(stopWatch.ElapsedMilliseconds, timeout - 10, 5000);
         }
 
         [ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsThreadingSupported))]