linux: Consolidate statfs implementations

The __NR_statfs64 syscall is supported on all architectures but
aarch64, mips64, riscv64, and x86_64.  And newer ABIs also uses
the new statfs64 interface (where the struct size is used as
second argument).

So the default implementation now uses:

  1. __NR_statfs64 for non-LFS call and handle overflow directly
     There is no need to handle __NR_statfs since all architectures
     that only support are LFS only.

  2. __NR_statfs if defined or __NR_statfs64 otherwise for LFS
     call.

Alpha is the only outlier, since it is a 64-bit architecture which
provides non-LFS interface and only provides __NR_statfs64 on
newer kernels (v5.1+).

Checked on x86_64-linux-gnu.

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

3 files changed, 81 insertions, 4 deletions

diff --git a/sysdeps/unix/sysv/linux/alpha/statfs.c b/sysdeps/unix/sysv/linux/alpha/statfs.c
new file mode 100644
index 0000000..3378976
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/statfs.c
@@ -0,0 +1,30 @@
+/* Return information about the filesystem on which FILE resides.  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
+__statfs (const char *file, struct statfs *buf)
+{
+  return INLINE_SYSCALL_CALL (statfs, file, buf);
+}
+libc_hidden_def (__statfs)
+weak_alias (__statfs, statfs)
diff --git a/sysdeps/unix/sysv/linux/alpha/statfs64.c b/sysdeps/unix/sysv/linux/alpha/statfs64.c
index fe39cc4..083b9a5 100644
--- a/sysdeps/unix/sysv/linux/alpha/statfs64.c
+++ b/sysdeps/unix/sysv/linux/alpha/statfs64.c
@@ -1 +1,51 @@
-#include <sysdeps/unix/sysv/linux/statfs64.c>
+/* Return information about the filesystem on which FILE resides.  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
+__statfs64 (const char *file, struct statfs64 *buf)
+{
+  int r = INLINE_SYSCALL_CALL (statfs64, file, sizeof (*buf), buf);
+#if __ASSUME_STATFS64 == 0
+  if (r == -1 && errno == ENOSYS)
+    {
+      struct statfs buf32;
+      if (__statfs (file, &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 (__statfs64, statfs64)
diff --git a/sysdeps/unix/sysv/linux/alpha/syscalls.list b/sysdeps/unix/sysv/linux/alpha/syscalls.list
index 8cb588c..c848fcb 100644
--- a/sysdeps/unix/sysv/linux/alpha/syscalls.list
+++ b/sysdeps/unix/sysv/linux/alpha/syscalls.list
@@ -27,6 +27,3 @@ getitimer	-	getitimer	i:ip	__getitimer	getitimer@@GLIBC_2.1
 setitimer	-	setitimer	i:ipP	__setitimer	setitimer@@GLIBC_2.1
 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
-statfs		-	statfs		i:sp	__statfs	statfs