use fstatfs to detect whether current file system supports shared locks for files opened for writing

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

@@ -22,129 +22,6 @@ static Sys()
 
         private const int MountPointFormatBufferSizeInBytes = 32;
 
-        /// <summary>
-        /// Internal FileSystem names and magic numbers taken from man(2) statfs
-        /// </summary>
-        /// <remarks>
-        /// These value names MUST be kept in sync with those in GetDriveType below,
-        /// where this enum must be a subset of the GetDriveType list, with the enum
-        /// values here exactly matching a string there.
-        /// </remarks>
-        internal enum UnixFileSystemTypes : long
-        {
-            adfs = 0xADF5,
-            affs = 0xADFF,
-            afs = 0x5346414F,
-            anoninode = 0x09041934,
-            aufs = 0x61756673,
-            autofs = 0x0187,
-            autofs4 = 0x6D4A556D,
-            befs = 0x42465331,
-            bdevfs = 0x62646576,
-            bfs = 0x1BADFACE,
-            binfmt_misc = 0x42494E4D,
-            bootfs = 0xA56D3FF9,
-            btrfs = 0x9123683E,
-            ceph = 0x00C36400,
-            cgroupfs = 0x0027E0EB,
-            cgroup2fs = 0x63677270,
-            cifs = 0xFF534D42,
-            coda = 0x73757245,
-            coherent = 0x012FF7B7,
-            configfs = 0x62656570,
-            cramfs = 0x28CD3D45,
-            debugfs = 0x64626720,
-            devfs = 0x1373,
-            devpts = 0x1CD1,
-            ecryptfs = 0xF15F,
-            efs = 0x00414A53,
-            exofs = 0x5DF5,
-            ext = 0x137D,
-            ext2_old = 0xEF51,
-            ext2 = 0xEF53,
-            ext3 = 0xEF53,
-            ext4 = 0xEF53,
-            fat = 0x4006,
-            fd = 0xF00D1E,
-            fhgfs = 0x19830326,
-            fuse = 0x65735546,
-            fuseblk = 0x65735546,
-            fusectl = 0x65735543,
-            futexfs = 0x0BAD1DEA,
-            gfsgfs2 = 0x1161970,
-            gfs2 = 0x01161970,
-            gpfs = 0x47504653,
-            hfs = 0x4244,
-            hfsplus = 0x482B,
-            hpfs = 0xF995E849,
-            hugetlbfs = 0x958458F6,
-            inodefs = 0x11307854,
-            inotifyfs = 0x2BAD1DEA,
-            isofs = 0x9660,
-            // isofs = 0x4004, // R_WIN
-            // isofs = 0x4000, // WIN
-            jffs = 0x07C0,
-            jffs2 = 0x72B6,
-            jfs = 0x3153464A,
-            kafs = 0x6B414653,
-            lofs = 0xEF53, /* loopback filesystem, magic same as ext2 */
-            logfs = 0xC97E8168,
-            lustre = 0x0BD00BD0,
-            minix_old = 0x137F, /* orig. minix */
-            minix = 0x138F, /* 30 char minix */
-            minix2 = 0x2468, /* minix V2 */
-            minix2v2 = 0x2478, /* MINIX V2, 30 char names */
-            minix3 = 0x4D5A,
-            mqueue = 0x19800202,
-            msdos = 0x4D44,
-            nfs = 0x6969,
-            nfsd = 0x6E667364,
-            nilfs = 0x3434,
-            novell = 0x564C,
-            ntfs = 0x5346544E,
-            openprom = 0x9FA1,
-            ocfs2 = 0x7461636F,
-            omfs = 0xC2993D87,
-            overlay = 0x794C7630,
-            overlayfs = 0x794C764F,
-            panfs = 0xAAD7AAEA,
-            pipefs = 0x50495045,
-            proc = 0x9FA0,
-            pstorefs = 0x6165676C,
-            qnx4 = 0x002F,
-            qnx6 = 0x68191122,
-            ramfs = 0x858458F6,
-            reiserfs = 0x52654973,
-            romfs = 0x7275,
-            rootfs = 0x53464846,
-            rpc_pipefs = 0x67596969,
-            samba = 0x517B,
-            securityfs = 0x73636673,
-            selinux = 0xF97CFF8C,
-            smb = 0x517B,
-            sockfs = 0x534F434B,
-            squashfs = 0x73717368,
-            sysfs = 0x62656572,
-            sysv2 = 0x012FF7B6,
-            sysv4 = 0x012FF7B5,
-            tmpfs = 0x01021994,
-            ubifs = 0x24051905,
-            udf = 0x15013346,
-            ufs = 0x00011954,
-            ufscigam = 0x54190100, // ufs byteswapped
-            ufs2 = 0x19540119,
-            usbdevice = 0x9FA2,
-            v9fs = 0x01021997,
-            vmhgfs = 0xBACBACBC,
-            vxfs = 0xA501FCF5,
-            vzfs = 0x565A4653,
-            xenfs = 0xABBA1974,
-            xenix = 0x012FF7B4,
-            xfs = 0x58465342,
-            xia = 0x012FD16D,
-            zfs = 0x2FC12FC1,
-        }
-
         [StructLayout(LayoutKind.Sequential)]
         internal struct MountPointInformation
         {

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

@@ -0,0 +1,145 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.InteropServices;
+using Microsoft.Win32.SafeHandles;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        /// <summary>
+        /// Internal FileSystem names and magic numbers taken from man(2) statfs
+        /// </summary>
+        /// <remarks>
+        /// These value names MUST be kept in sync with those in GetDriveType (moved to Interop.MountPoints.FormatInfo.cs),
+        /// where this enum must be a subset of the GetDriveType list, with the enum
+        /// values here exactly matching a string there.
+        /// </remarks>
+        internal enum UnixFileSystemTypes : long
+        {
+            adfs = 0xADF5,
+            affs = 0xADFF,
+            afs = 0x5346414F,
+            anoninode = 0x09041934,
+            aufs = 0x61756673,
+            autofs = 0x0187,
+            autofs4 = 0x6D4A556D,
+            befs = 0x42465331,
+            bdevfs = 0x62646576,
+            bfs = 0x1BADFACE,
+            binfmt_misc = 0x42494E4D,
+            bootfs = 0xA56D3FF9,
+            btrfs = 0x9123683E,
+            ceph = 0x00C36400,
+            cgroupfs = 0x0027E0EB,
+            cgroup2fs = 0x63677270,
+            cifs = 0xFF534D42,
+            coda = 0x73757245,
+            coherent = 0x012FF7B7,
+            configfs = 0x62656570,
+            cramfs = 0x28CD3D45,
+            debugfs = 0x64626720,
+            devfs = 0x1373,
+            devpts = 0x1CD1,
+            ecryptfs = 0xF15F,
+            efs = 0x00414A53,
+            exofs = 0x5DF5,
+            ext = 0x137D,
+            ext2_old = 0xEF51,
+            ext2 = 0xEF53,
+            ext3 = 0xEF53,
+            ext4 = 0xEF53,
+            fat = 0x4006,
+            fd = 0xF00D1E,
+            fhgfs = 0x19830326,
+            fuse = 0x65735546,
+            fuseblk = 0x65735546,
+            fusectl = 0x65735543,
+            futexfs = 0x0BAD1DEA,
+            gfsgfs2 = 0x1161970,
+            gfs2 = 0x01161970,
+            gpfs = 0x47504653,
+            hfs = 0x4244,
+            hfsplus = 0x482B,
+            hpfs = 0xF995E849,
+            hugetlbfs = 0x958458F6,
+            inodefs = 0x11307854,
+            inotifyfs = 0x2BAD1DEA,
+            isofs = 0x9660,
+            // isofs = 0x4004, // R_WIN
+            // isofs = 0x4000, // WIN
+            jffs = 0x07C0,
+            jffs2 = 0x72B6,
+            jfs = 0x3153464A,
+            kafs = 0x6B414653,
+            lofs = 0xEF53, /* loopback filesystem, magic same as ext2 */
+            logfs = 0xC97E8168,
+            lustre = 0x0BD00BD0,
+            minix_old = 0x137F, /* orig. minix */
+            minix = 0x138F, /* 30 char minix */
+            minix2 = 0x2468, /* minix V2 */
+            minix2v2 = 0x2478, /* MINIX V2, 30 char names */
+            minix3 = 0x4D5A,
+            mqueue = 0x19800202,
+            msdos = 0x4D44,
+            nfs = 0x6969,
+            nfsd = 0x6E667364,
+            nilfs = 0x3434,
+            novell = 0x564C,
+            ntfs = 0x5346544E,
+            openprom = 0x9FA1,
+            ocfs2 = 0x7461636F,
+            omfs = 0xC2993D87,
+            overlay = 0x794C7630,
+            overlayfs = 0x794C764F,
+            panfs = 0xAAD7AAEA,
+            pipefs = 0x50495045,
+            proc = 0x9FA0,
+            pstorefs = 0x6165676C,
+            qnx4 = 0x002F,
+            qnx6 = 0x68191122,
+            ramfs = 0x858458F6,
+            reiserfs = 0x52654973,
+            romfs = 0x7275,
+            rootfs = 0x53464846,
+            rpc_pipefs = 0x67596969,
+            samba = 0x517B,
+            securityfs = 0x73636673,
+            selinux = 0xF97CFF8C,
+            smb = 0x517B,
+            smb2 = 0xFE534D42,
+            sockfs = 0x534F434B,
+            squashfs = 0x73717368,
+            sysfs = 0x62656572,
+            sysv2 = 0x012FF7B6,
+            sysv4 = 0x012FF7B5,
+            tmpfs = 0x01021994,
+            ubifs = 0x24051905,
+            udf = 0x15013346,
+            ufs = 0x00011954,
+            ufscigam = 0x54190100, // ufs byteswapped
+            ufs2 = 0x19540119,
+            usbdevice = 0x9FA2,
+            v9fs = 0x01021997,
+            vmhgfs = 0xBACBACBC,
+            vxfs = 0xA501FCF5,
+            vzfs = 0x565A4653,
+            xenfs = 0xABBA1974,
+            xenix = 0x012FF7B4,
+            xfs = 0x58465342,
+            xia = 0x012FD16D,
+            zfs = 0x2FC12FC1,
+        }
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetFileSystemType")]
+        private static extern long GetFileSystemType(SafeFileHandle fd);
+
+        internal static bool TryGetFileSystemType(SafeFileHandle fd, out UnixFileSystemTypes fileSystemType)
+        {
+            long fstatfsResult = GetFileSystemType(fd);
+            fileSystemType = (UnixFileSystemTypes)fstatfsResult;
+            return fstatfsResult != -1;
+        }
+    }
+}

src/libraries/Native/Unix/Common/pal_config.h.in

@@ -5,6 +5,8 @@
 #cmakedefine01 HAVE_MMAP64
 #cmakedefine01 HAVE_FTRUNCATE64
 #cmakedefine01 HAVE_POSIX_FADVISE64
+#cmakedefine01 HAVE_STATFS_VFS
+#cmakedefine01 HAVE_STATFS_MOUNT
 #cmakedefine01 HAVE_FLOCK64
 #cmakedefine01 HAVE_F_DUPFD_CLOEXEC
 #cmakedefine01 HAVE_F_FULLFSYNC

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

@@ -103,6 +103,7 @@ static const Entry s_sysNative[] =
     DllImportEntry(SystemNative_INotifyRemoveWatch)
     DllImportEntry(SystemNative_RealPath)
     DllImportEntry(SystemNative_GetPeerID)
+    DllImportEntry(SystemNative_GetFileSystemType)
     DllImportEntry(SystemNative_LockFileRegion)
     DllImportEntry(SystemNative_LChflags)
     DllImportEntry(SystemNative_LChflagsCanSetHiddenFlag)

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

@@ -35,6 +35,11 @@
 #if HAVE_INOTIFY
 #include <sys/inotify.h>
 #endif
+#if HAVE_STATFS_VFS // Linux
+#include <sys/vfs.h>
+#elif HAVE_STATFS_MOUNT // BSD
+#include <sys/mount.h>
+#endif
 
 #ifdef _AIX
 #include <alloca.h>
@@ -1379,6 +1384,20 @@ static int16_t ConvertLockType(int16_t managedLockType)
     }
 }
 
+int64_t SystemNative_GetFileSystemType(intptr_t fd)
+{
+#if HAVE_STATFS_VFS || HAVE_STATFS_MOUNT
+    int statfsRes;
+    struct statfs statfsArgs;
+    // for our needs (get file system type) statfs is always enough and there is no need to use statfs64
+    // which got deprecated in macOS 10.6, in favor of statfs
+    while ((statfsRes = fstatfs(ToFileDescriptor(fd), &statfsArgs)) == -1 && errno == EINTR) ;
+    return statfsRes == -1 ? (int64_t)-1 : (int64_t)statfsArgs.f_type;
+#else
+    #error "Platform doesn't support fstatfs"
+#endif
+}
+
 int32_t SystemNative_LockFileRegion(intptr_t fd, int64_t offset, int64_t length, int16_t lockType)
 {
     int16_t unixLockType = ConvertLockType(lockType);

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

@@ -710,6 +710,11 @@ PALEXPORT char* SystemNative_RealPath(const char* path);
 */
 PALEXPORT int32_t SystemNative_GetPeerID(intptr_t socket, uid_t* euid);
 
+/**
+* Returns file system type on success, or -1 on error.
+*/
+PALEXPORT int64_t SystemNative_GetFileSystemType(intptr_t fd);
+
 /**
 * Attempts to lock/unlock the region of the file "fd" specified by the offset and length. lockType
 * can be set to F_UNLCK (2) for unlock or F_WRLCK (3) for lock.

src/libraries/Native/Unix/configure.cmake

@@ -108,6 +108,28 @@ check_c_source_compiles(
 
 # /in_pktinfo
 
+check_c_source_compiles(
+    "
+    #include <sys/vfs.h>
+    int main(void)
+    {
+        struct statfs s;
+        return 0;
+    }
+    "
+    HAVE_STATFS_VFS)
+
+check_c_source_compiles(
+    "
+    #include <sys/mount.h>
+    int main(void)
+    {
+        struct statfs s;
+        return 0;
+    }
+    "
+    HAVE_STATFS_MOUNT)
+
 check_c_source_compiles(
     "
     #include <fcntl.h>

src/libraries/System.IO.FileSystem.DriveInfo/src/System.IO.FileSystem.DriveInfo.csproj

@@ -56,6 +56,8 @@
              Link="Common\Interop\Unix\Interop.Libraries.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.Errors.cs"
              Link="Common\Interop\Unix\Interop.Errors.cs" />
+    <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.UnixFileSystemTypes.cs"
+             Link="Common\Interop\Unix\Interop.UnixFileSystemTypes.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.IOErrors.cs"
              Link="Common\Interop\Unix\Interop.IOErrors.cs" />
     <Compile Include="$(CommonPath)System\IO\PathInternal.Unix.cs"