[05/10] 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 architecture
     that only support is 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_fstatfs64 on
newer kernels.

Checked on x86_64-linux-gnu.
---
 .../{generic/wordsize-32 => alpha}/statfs.c   | 16 ++---
 sysdeps/unix/sysv/linux/alpha/statfs64.c      | 52 +++++++++++++-
 sysdeps/unix/sysv/linux/alpha/syscalls.list   |  3 -
 .../sysv/linux/mips/mips64/n64/statfs64.c     |  1 -
 .../sysv/linux/mips/mips64/n64/syscalls.list  |  2 -
 sysdeps/unix/sysv/linux/statfs.c              | 61 ++++++++++++++++
 sysdeps/unix/sysv/linux/statfs64.c            | 69 +++----------------
 .../unix/sysv/linux/wordsize-64/statfs64.c    |  1 -
 .../unix/sysv/linux/wordsize-64/syscalls.list |  1 -
 9 files changed, 125 insertions(+), 81 deletions(-)
 rename sysdeps/unix/sysv/linux/{generic/wordsize-32 => alpha}/statfs.c (72%)
 delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/statfs64.c
 create mode 100644 sysdeps/unix/sysv/linux/statfs.c
 delete mode 100644 sysdeps/unix/sysv/linux/wordsize-64/statfs64.c
  

On 2/8/21 4:49 PM, Adhemerval Zanella via Libc-alpha wrote:
> 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 architecture
>      that only support is are LFS only.

OK.

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

OK.

> Alpha is the only outlier, since it is a 64-bit architecture which
> provides non-LFS interface and only provides __NR_fstatfs64 on
> newer kernels.

OK.

LGTM.

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

> Checked on x86_64-linux-gnu.
> ---
>  .../{generic/wordsize-32 => alpha}/statfs.c   | 16 ++---
>  sysdeps/unix/sysv/linux/alpha/statfs64.c      | 52 +++++++++++++-
>  sysdeps/unix/sysv/linux/alpha/syscalls.list   |  3 -
>  .../sysv/linux/mips/mips64/n64/statfs64.c     |  1 -
>  .../sysv/linux/mips/mips64/n64/syscalls.list  |  2 -
>  sysdeps/unix/sysv/linux/statfs.c              | 61 ++++++++++++++++
>  sysdeps/unix/sysv/linux/statfs64.c            | 69 +++----------------
>  .../unix/sysv/linux/wordsize-64/statfs64.c    |  1 -
>  .../unix/sysv/linux/wordsize-64/syscalls.list |  1 -
>  9 files changed, 125 insertions(+), 81 deletions(-)
>  rename sysdeps/unix/sysv/linux/{generic/wordsize-32 => alpha}/statfs.c (72%)
>  delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/statfs64.c
>  create mode 100644 sysdeps/unix/sysv/linux/statfs.c
>  delete mode 100644 sysdeps/unix/sysv/linux/wordsize-64/statfs64.c
> 
> diff --git a/sysdeps/unix/sysv/linux/generic/wordsize-32/statfs.c b/sysdeps/unix/sysv/linux/alpha/statfs.c
> similarity index 72%
> rename from sysdeps/unix/sysv/linux/generic/wordsize-32/statfs.c
> rename to sysdeps/unix/sysv/linux/alpha/statfs.c
> index 2c51fbf1b0..33789768ed 100644
> --- a/sysdeps/unix/sysv/linux/generic/wordsize-32/statfs.c
> +++ b/sysdeps/unix/sysv/linux/alpha/statfs.c
> @@ -1,6 +1,6 @@
> -/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
> +/* 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.
> -   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
> @@ -13,24 +13,18 @@
>     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
> +   License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#include <errno.h>
>  #include <sys/statfs.h>
> -#include <kernel_stat.h>
>  #include <sysdep.h>
> -
> -#if !STATFS_IS_STATFS64
> -#include "overflow.h"
> +#include <kernel_stat.h>
>  
>  /* Return information about the filesystem on which FILE resides.  */
>  int
>  __statfs (const char *file, struct statfs *buf)
>  {
> -  int rc = INLINE_SYSCALL (statfs64, 3, file, sizeof (*buf), buf);
> -  return rc ?: statfs_overflow (buf);
> +  return INLINE_SYSCALL_CALL (statfs, file, buf);
>  }
>  libc_hidden_def (__statfs)
>  weak_alias (__statfs, statfs)
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/alpha/statfs64.c b/sysdeps/unix/sysv/linux/alpha/statfs64.c
> index fe39cc4685..083b9a59f3 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 8cb588cb2c..c848fcbd99 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
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/statfs64.c b/sysdeps/unix/sysv/linux/mips/mips64/n64/statfs64.c
> deleted file mode 100644
> index 6e25b021ab..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/statfs64.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -/* Empty.  */
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
> index b6a0c92829..e4e16dfa49 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
> @@ -4,6 +4,4 @@ prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
>  
>  fanotify_mark	EXTRA	fanotify_mark	i:iiiis	fanotify_mark
>  
> -statfs		-	statfs		i:sp	__statfs	statfs statfs64 __statfs64
> -
>  sendfile	-	sendfile	i:iipi	sendfile	sendfile64
> diff --git a/sysdeps/unix/sysv/linux/statfs.c b/sysdeps/unix/sysv/linux/statfs.c
> new file mode 100644
> index 0000000000..ee248b4212
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/statfs.c
> @@ -0,0 +1,61 @@
> +/* 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
> +   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
> +__statfs (const char *file, struct statfs *buf)
> +{
> +  struct statfs64 buf64;
> +  int rc = INLINE_SYSCALL_CALL (statfs64, file, sizeof (buf64), &buf64);
> +  if (rc == 0)
> +    {
> +      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 rc;
> +}
> +libc_hidden_def (__statfs)
> +weak_alias (__statfs, statfs)
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/statfs64.c b/sysdeps/unix/sysv/linux/statfs64.c
> index c52b3d8ae6..4f68212e9f 100644
> --- a/sysdeps/unix/sysv/linux/statfs64.c
> +++ b/sysdeps/unix/sysv/linux/statfs64.c
> @@ -16,79 +16,26 @@
>     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 __statfs __statfs_disable
> +#define statfs statfs_disable
> +#include <sys/statfs.h>
>  #include <sysdep.h>
>  #include <kernel_stat.h>
> -
> -/* Hide the prototypes for __statfs and statfs so that GCC will not
> -   complain about the different function signatures if they are aliased
> -   to  __stat64.  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 __statfs __statfs_disable
> -# define statfs statfs_disable
> -#endif
> -#include <sys/statfs.h>
> -
> -#include <kernel-features.h>
> -
> -
> -# if __ASSUME_STATFS64 == 0
> -int __no_statfs64 attribute_hidden;
> -#endif
> +#undef __statfs
> +#undef statfs
>  
>  /* Return information about the filesystem on which FILE resides.  */
>  int
>  __statfs64 (const char *file, struct statfs64 *buf)
>  {
>  #ifdef __NR_statfs64
> -# if __ASSUME_STATFS64 == 0
> -  if (! __no_statfs64)
> -# endif
> -    {
> -      int result = INLINE_SYSCALL (statfs64, 3, file, 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 (__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));
> -
> -  return 0;
> +  return INLINE_SYSCALL_CALL (statfs64, file, sizeof (*buf), buf);
> +#else
> +  return INLINE_SYSCALL_CALL (statfs, file, buf);
>  #endif
>  }
>  weak_alias (__statfs64, statfs64)
>  
> -#undef __statfs
> -#undef statfs
> -
>  #if STATFS_IS_STATFS64
>  weak_alias (__statfs64, __statfs)
>  weak_alias (__statfs64, statfs)
> diff --git a/sysdeps/unix/sysv/linux/wordsize-64/statfs64.c b/sysdeps/unix/sysv/linux/wordsize-64/statfs64.c
> deleted file mode 100644
> index 06bc68826f..0000000000
> --- a/sysdeps/unix/sysv/linux/wordsize-64/statfs64.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -/* statfs64 is the same as statfs. */
> diff --git a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> index 5a0c910847..68e3c60536 100644
> --- a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> @@ -1,6 +1,5 @@
>  # File name	Caller	Syscall name	# args	Strong name	Weak names
>  
> -statfs		-	statfs		i:sp	__statfs	statfs statfs64
>  sendfile	-	sendfile	i:iipi	sendfile	sendfile64
>  prlimit		EXTRA	prlimit64	i:iipp	prlimit		prlimit64
>  
>