linux: Consolidate fstatfs implementations

The __NR_fstatfs64 syscall is supported on all architectures but
aarch64, mips64, riscv64, and x86_64.  And newer ABIs also uses
the new fstatfs64 interface (where the struct size is used as
first argument).

So the default implementation now uses:

  1. __NR_fstatfs64 for non-LFS call and handle overflow directly
     There is no need to handle __NR_fstatfs since all architectures
     that only support are LFS only.

  2. __NR_fstatfs if defined or __NR_fstatfs64 otherwise for LFS
     call.

Alpha is the only outlier, it is a 64-bit architecture which
provides non-LFS interface and only provides __NR_fstatfs64 on
newer kernels (5.1+).

Checked on x86_64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

include/sys/statfs.h

@@ -6,12 +6,11 @@
 /* Now define the internal interfaces.  */
 extern int __statfs (const char *__file, struct statfs *__buf);
 libc_hidden_proto (__statfs)
-extern int __fstatfs (int __fildes, struct statfs *__buf)
+extern int __fstatfs (int __fildes, struct statfs *__buf);
-     attribute_hidden;
+libc_hidden_proto (__fstatfs)
 extern int __statfs64 (const char *__file, struct statfs64 *__buf)
      attribute_hidden;
-extern int __fstatfs64 (int __fildes, struct statfs64 *__buf)
+extern int __fstatfs64 (int __fildes, struct statfs64 *__buf);
-     attribute_hidden;
 
 # endif /* !_ISOMAC */
 #endif

sysdeps/unix/sysv/linux/alpha/fstatfs.c

@@ -1,6 +1,6 @@
-/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
+/* Get filesystem statistics.  Linux/alpha.
+   Copyright (C) 2011-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
-   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -18,18 +18,13 @@
 
 #include <sys/statfs.h>
 #include <kernel_stat.h>
-#include <stddef.h>
 #include <sysdep.h>
 
-#if !STATFS_IS_STATFS64
-#include "overflow.h"
-
 /* Return information about the filesystem on which FD resides.  */
 int
 __fstatfs (int fd, struct statfs *buf)
 {
-  int rc = INLINE_SYSCALL (fstatfs64, 3, fd, sizeof (*buf), buf);
+  return INLINE_SYSCALL_CALL (fstatfs, fd, buf);
-  return rc ?: statfs_overflow (buf);
 }
+libc_hidden_def (__fstatfs)
 weak_alias (__fstatfs, fstatfs)
-#endif

sysdeps/unix/sysv/linux/alpha/fstatfs64.c

@@ -1 +1,51 @@
-#include <sysdeps/unix/sysv/linux/fstatfs64.c>
+/* Get filesystem statistics.  Linux/alpha.
+   Copyright (C) 1996-2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/statfs.h>
+#include <sysdep.h>
+#include <kernel_stat.h>
+
+/* Return information about the filesystem on which FILE resides.  */
+int
+__fstatfs64 (int fd, struct statfs64 *buf)
+{
+  int r = INLINE_SYSCALL_CALL (fstatfs64, fd, sizeof (*buf), buf);
+#if __ASSUME_STATFS64 == 0
+  if (r == -1 && errno == ENOSYS)
+    {
+      struct statfs buf32;
+      if (__fstatfs (fd, &buf32) < 0)
+	return -1;
+
+      buf->f_type = buf32.f_type;
+      buf->f_bsize = buf32.f_bsize;
+      buf->f_blocks = buf32.f_blocks;
+      buf->f_bfree = buf32.f_bfree;
+      buf->f_bavail = buf32.f_bavail;
+      buf->f_files = buf32.f_files;
+      buf->f_ffree = buf32.f_ffree;
+      buf->f_fsid = buf32.f_fsid;
+      buf->f_namelen = buf32.f_namelen;
+      buf->f_frsize = buf32.f_frsize;
+      buf->f_flags = buf32.f_flags;
+      memcpy (buf->f_spare, buf32.f_spare, sizeof (buf32.f_spare));
+    }
+#endif
+  return r;
+}
+weak_alias (__fstatfs64, fstatfs64)

sysdeps/unix/sysv/linux/alpha/syscalls.list

@@ -29,5 +29,4 @@ utimes		-	utimes		i:sp	__utimes	utimes@@GLIBC_2.1
 getrusage	-	getrusage	i:ip	__getrusage	getrusage@@GLIBC_2.1
 
 # avoid 64-bit aliases on 32-bit statfs syscalls
-fstatfs		-	fstatfs		i:ip	__fstatfs	fstatfs
 statfs		-	statfs		i:sp	__statfs	statfs

sysdeps/unix/sysv/linux/fstatfs.c

@@ -0,0 +1,62 @@
+/* Get filesystem statistics.  Linux version.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/statfs.h>
+#include <time.h>
+#include <sysdep.h>
+#include <kernel_stat.h>
+
+#if !STATFS_IS_STATFS64
+
+/* Return information about the filesystem on which FILE resides.  */
+int
+__fstatfs (int fd, struct statfs *buf)
+{
+  struct statfs64 buf64;
+  int rc = INLINE_SYSCALL_CALL (fstatfs64, fd, sizeof (buf64), &buf64);
+  if (rc != 0)
+    return rc;
+
+  buf->f_type = buf64.f_type;
+  buf->f_bsize = buf64.f_bsize;
+  buf->f_blocks = buf64.f_blocks;
+  buf->f_bfree = buf64.f_bfree;
+  buf->f_bavail = buf64.f_bavail;
+  buf->f_files = buf64.f_files;
+  buf->f_ffree = buf64.f_ffree;
+  buf->f_fsid = buf64.f_fsid;
+  buf->f_namelen = buf64.f_namelen;
+  buf->f_frsize = buf64.f_frsize;
+  buf->f_flags = buf64.f_flags;
+  memcpy (buf->f_spare, buf64.f_spare, sizeof (buf64.f_spare));
+
+  if ((fsblkcnt_t) buf64.f_blocks != buf64.f_blocks
+      || (fsblkcnt_t) buf64.f_bfree != buf64.f_bfree
+      || (fsblkcnt_t) buf64.f_bavail != buf64.f_bavail
+      || (fsblkcnt_t) buf64.f_files != buf64.f_files
+      || (fsblkcnt_t) buf64.f_ffree != buf64.f_ffree)
+   {
+     __set_errno (EOVERFLOW);
+     return -1;
+   }
+
+  return 0;
+}
+libc_hidden_def (__fstatfs)
+weak_alias (__fstatfs, fstatfs)
+#endif

sysdeps/unix/sysv/linux/fstatfs64.c

@@ -16,77 +16,28 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
+#define __fstatfs __fstatfs_disable
-#include <string.h>
+#define fstatfs fstatfs_disable
-#include <stddef.h>
+#include <sys/statfs.h>
 #include <sysdep.h>
 #include <kernel_stat.h>
-
+#undef __fstatfs
-/* Hide the prototypes for __fstatfs and fstatfs so that GCC will not
+#undef fstatfs
-   complain about the different function signatures if they are aliased
-   to  __fstat64.  If STATFS_IS_STATFS64 is not zero then the statfs and
-   statfs64 structures have an identical layout but different type names.  */
-
-#if STATFS_IS_STATFS64
-# define __fstatfs __fstatfs_disable
-# define fstatfs fstatfs_disable
-#endif
-#include <sys/statfs.h>
-
-#include <kernel-features.h>
-
-/* Defined in statfs64.c.  */
-extern int __no_statfs64 attribute_hidden;
 
 /* Return information about the filesystem on which FD resides.  */
 int
 __fstatfs64 (int fd, struct statfs64 *buf)
 {
 #ifdef __NR_fstatfs64
-# if __ASSUME_STATFS64 == 0
+  return INLINE_SYSCALL_CALL (fstatfs64, fd, sizeof (*buf), buf);
-  if (! __no_statfs64)
+#else
-# endif
+  return INLINE_SYSCALL_CALL (fstatfs, fd, buf);
-    {
-      int result = INLINE_SYSCALL (fstatfs64, 3, fd, sizeof (*buf), buf);
-
-# if __ASSUME_STATFS64 == 0
-      if (result == 0 || errno != ENOSYS)
-# endif
-	return result;
-
-# if __ASSUME_STATFS64 == 0
-      __no_statfs64 = 1;
-# endif
-    }
-#endif
-
-#if __ASSUME_STATFS64 == 0
-  struct statfs buf32;
-
-  if (__fstatfs (fd, &buf32) < 0)
-    return -1;
-
-  buf->f_type = buf32.f_type;
-  buf->f_bsize = buf32.f_bsize;
-  buf->f_blocks = buf32.f_blocks;
-  buf->f_bfree = buf32.f_bfree;
-  buf->f_bavail = buf32.f_bavail;
-  buf->f_files = buf32.f_files;
-  buf->f_ffree = buf32.f_ffree;
-  buf->f_fsid = buf32.f_fsid;
-  buf->f_namelen = buf32.f_namelen;
-  buf->f_frsize = buf32.f_frsize;
-  memcpy (buf->f_spare, buf32.f_spare, sizeof (buf32.f_spare));
-
-  return 0;
 #endif
 }
 weak_alias (__fstatfs64, fstatfs64)
 
-#undef __fstatfs
-#undef fstatfs
-
 #if STATFS_IS_STATFS64
 weak_alias (__fstatfs64, __fstatfs)
 weak_alias (__fstatfs64, fstatfs)
+libc_hidden_ver (__fstatfs64, __fstatfs)
 #endif

sysdeps/unix/sysv/linux/mips/mips64/n64/fstatfs64.c

@@ -1 +0,0 @@
-/* Empty.  */

sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list

@@ -4,7 +4,6 @@ prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
 
 fanotify_mark	EXTRA	fanotify_mark	i:iiiis	fanotify_mark
 
-fstatfs		-	fstatfs		i:ip	__fstatfs	fstatfs fstatfs64 __fstatfs64
 statfs		-	statfs		i:sp	__statfs	statfs statfs64 __statfs64
 
 sendfile	-	sendfile	i:iipi	sendfile	sendfile64

sysdeps/unix/sysv/linux/wordsize-64/fstatfs64.c

@@ -1 +0,0 @@
-/* fstatfs64 is the same as fstatfs. */

sysdeps/unix/sysv/linux/wordsize-64/syscalls.list

@@ -1,6 +1,5 @@
 # File name	Caller	Syscall name	# args	Strong name	Weak names
 
-fstatfs		-	fstatfs		i:ip	__fstatfs	fstatfs fstatfs64 __fstatfs64
 statfs		-	statfs		i:sp	__statfs	statfs statfs64
 sendfile	-	sendfile	i:iipi	sendfile	sendfile64
 prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64