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>

1 files changed, 9 insertions, 58 deletions

diff --git a/sysdeps/unix/sysv/linux/fstatfs64.c b/sysdeps/unix/sysv/linux/fstatfs64.c
index b5ff74d..e6aa643 100644
--- a/sysdeps/unix/sysv/linux/fstatfs64.c
+++ b/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>
-#include <string.h>
-#include <stddef.h>
+#define __fstatfs __fstatfs_disable
+#define fstatfs fstatfs_disable
+#include <sys/statfs.h>
 #include <sysdep.h>
 #include <kernel_stat.h>
-
-/* Hide the prototypes for __fstatfs and fstatfs so that GCC will not
-   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;
+#undef __fstatfs
+#undef fstatfs
 
 /* Return information about the filesystem on which FD resides.  */
 int
 __fstatfs64 (int fd, struct statfs64 *buf)
 {
 #ifdef __NR_fstatfs64
-# if __ASSUME_STATFS64 == 0
-  if (! __no_statfs64)
-# endif
-    {
-      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;
+  return INLINE_SYSCALL_CALL (fstatfs64, fd, sizeof (*buf), buf);
+#else
+  return INLINE_SYSCALL_CALL (fstatfs, fd, buf);
 #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