Re: [PATCH 2/2] Deprecate ustat syscall interface

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 23/04/2018 20:16, Joseph Myers wrote:
> Again, this is the wrong way to obsolete something - a new symbol version 
> should not be added as part of deprecation.  And, any deprecation needs a 
> NEWS enty.
> 

Below it is an updated patch which addresses the issues you brought.

---

As for sysctl, ustat has been deprecated in favor of fstatfs.  Newer
ports which uses generic interface builds a stub version which
returns ENOSYS.

This patch deprecate ustat interface by issuing ENOSYS as default
and adds compat symbol for architectures which still defines
__NR_ustat.

Checked on x86_64-linux-gnu and i686-linux-gnu.  Also checked with a
check-abi on all affected ABIs.

	* NEWS: Add ustat.h deprecation entry.
	* bits/ustat.h: Remove file.
	* misc/sys/ustat.h: Likewise.
	* misc/ustat.h: Likewise.
	* sysdeps/unix/sysv/linux/generic/ustat.c: Likewise.
	* misc/Makefile (headers): Remove ustat.h and sys/ustat.h.
	* misc/ustat.c (__ustat): Rename to __old_ustat and export only in
	compatibility mode.
	* sysdeps/unix/sysv/linux/ustat.c (__ustat): Likewise.
	* sysdeps/unix/sysv/linux/mips/ustat.c: Define DEV_TO_KDEV and use
	generic Linux implementation.
---
 ChangeLog                               | 12 ++++++++
 NEWS                                    |  5 ++++
 bits/ustat.h                            | 30 --------------------
 misc/Makefile                           |  2 +-
 misc/sys/ustat.h                        | 37 ------------------------
 misc/ustat.c                            | 22 ++++++++++++---
 misc/ustat.h                            |  1 -
 sysdeps/unix/sysv/linux/generic/ustat.c | 32 ---------------------
 sysdeps/unix/sysv/linux/mips/ustat.c    | 21 +++++---------
 sysdeps/unix/sysv/linux/ustat.c         | 50 +++++++++++++++++++++++----------
 10 files changed, 78 insertions(+), 134 deletions(-)
 delete mode 100644 bits/ustat.h
 delete mode 100644 misc/sys/ustat.h
 delete mode 100644 misc/ustat.h
 delete mode 100644 sysdeps/unix/sysv/linux/generic/ustat.c

diff --git a/NEWS b/NEWS
index ffe3bb4..f8cd879 100644
--- a/NEWS
+++ b/NEWS
@@ -62,6 +62,11 @@ Deprecated and removed features, and other changes affecting compatibility:
    of /proc/sys.  A compatibility symbol is still provided, however it is
    not being defined for static linking or for new ports.
 
+ * The header file <ustat.h> is no longer installed.  Software should
+   be updated to use 'statfs' instead.  A compatibility symbol is still
+   provided, however it is not being defined for static linking or for
+   new ports.
+
 Changes to build and runtime requirements:
 
   [Add changes to build and runtime requirements here]
diff --git a/bits/ustat.h b/bits/ustat.h
deleted file mode 100644
index ac9acca..0000000
--- a/bits/ustat.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Copyright (C) 1997-2018 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
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _SYS_USTAT_H
-# error "Never include <bits/ustat.h> directly; use <sys/ustat.h> instead."
-#endif
-
-#include <sys/types.h>
-
-struct ustat
-  {
-    __daddr_t f_tfree;		/* Number of free blocks.  */
-    __ino_t f_tinode;		/* Number of free inodes.  */
-    char f_fname[6];
-    char f_fpack[6];
-  };
diff --git a/misc/Makefile b/misc/Makefile
index a5076b3..a1d568b 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -31,7 +31,7 @@ headers	:= sys/uio.h bits/uio-ext.h bits/uio_lim.h \
 	   sys/mman.h sys/param.h bits/param.h \
 	   fstab.h mntent.h search.h err.h error.h \
 	   sys/queue.h sysexits.h syscall.h sys/syscall.h sys/swap.h \
-	   sys/select.h ustat.h sys/ustat.h bits/ustat.h sys/sysinfo.h \
+	   sys/select.h sys/sysinfo.h \
 	   regexp.h bits/select.h bits/mman.h sys/xattr.h \
 	   syslog.h sys/syslog.h \
 	   bits/syslog.h bits/syslog-ldbl.h bits/syslog-path.h bits/error.h \
diff --git a/misc/sys/ustat.h b/misc/sys/ustat.h
deleted file mode 100644
index 828ca41..0000000
--- a/misc/sys/ustat.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Header describing obsolete `ustat' interface.
-   Copyright (C) 1996-2018 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
-   <http://www.gnu.org/licenses/>.  */
-
-/*
- * This interface is obsolete.  Use <sys/statfs.h> instead.
- */
-
-#ifndef _SYS_USTAT_H
-#define	_SYS_USTAT_H	1
-
-#include <features.h>
-
-#include <sys/types.h>
-#include <bits/ustat.h>
-
-__BEGIN_DECLS
-
-extern int ustat (__dev_t __dev, struct ustat *__ubuf) __THROW;
-
-__END_DECLS
-
-#endif /* sys/ustat.h */
diff --git a/misc/ustat.c b/misc/ustat.c
index e5abeda..717d6d7 100644
--- a/misc/ustat.c
+++ b/misc/ustat.c
@@ -16,14 +16,28 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <unistd.h>
-#include <errno.h>
-#include <sys/ustat.h>
+#include <shlib-compat.h>
+
+/* This deprecated syscall is no longer used (replaced with fstat).  */
+#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_28)
+
+# include <unistd.h>
+# include <errno.h>
+
+struct ustat
+ {
+   __daddr_t f_tfree;         /* Number of free blocks.  */
+   __ino_t f_tinode;          /* Number of free inodes.  */
+   char f_fname[6];
+   char f_fpack[6];
+};
 
 int
-ustat (dev_t dev, struct ustat *ust)
+__old_ustat (dev_t dev, struct ustat *ust)
 {
   __set_errno (ENOSYS);
   return -1;
 }
 stub_warning (ustat)
+compat_symbol (libc, __old_ustat, ustat, GLIBC_2_0);
+#endif
diff --git a/misc/ustat.h b/misc/ustat.h
deleted file mode 100644
index cba150e..0000000
--- a/misc/ustat.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <sys/ustat.h>
diff --git a/sysdeps/unix/sysv/linux/generic/ustat.c b/sysdeps/unix/sysv/linux/generic/ustat.c
deleted file mode 100644
index d4f9c89..0000000
--- a/sysdeps/unix/sysv/linux/generic/ustat.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Copyright (C) 2011-2018 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <sys/ustat.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-/* This deprecated syscall is no longer used (replaced with fstat).  */
-int
-ustat (dev_t dev, struct ustat *ubuf)
-{
-  __set_errno (ENOSYS);
-  return -1;
-}
-stub_warning (ustat)
diff --git a/sysdeps/unix/sysv/linux/mips/ustat.c b/sysdeps/unix/sysv/linux/mips/ustat.c
index 1f597c9..786a5ef 100644
--- a/sysdeps/unix/sysv/linux/mips/ustat.c
+++ b/sysdeps/unix/sysv/linux/mips/ustat.c
@@ -16,20 +16,13 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <sys/ustat.h>
 #include <sys/sysmacros.h>
 
-#include <sysdep.h>
-#include <sys/syscall.h>
+#define DEV_TO_KDEV(__dev)					\
+  ({								\
+    unsigned long k_dev;					\
+    k_dev = ((major (dev) & 0xff) << 8) | (minor (dev) & 0xff);	\
+    k_dev;							\
+  })
 
-int
-ustat (dev_t dev, struct ustat *ubuf)
-{
-  unsigned long k_dev;
-
-  /* We must convert the value to dev_t type used by the kernel.  */
-  k_dev = ((major (dev) & 0xff) << 8) | (minor (dev) & 0xff);
-
-  return INLINE_SYSCALL (ustat, 2, k_dev, ubuf);
-}
+#include <sysdeps/unix/sysv/linux/ustat.c>
diff --git a/sysdeps/unix/sysv/linux/ustat.c b/sysdeps/unix/sysv/linux/ustat.c
index 8e73faa..accbc86 100644
--- a/sysdeps/unix/sysv/linux/ustat.c
+++ b/sysdeps/unix/sysv/linux/ustat.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1997-2018 Free Software Foundation, Inc.
+/* Get filesystem statistics (deprecated).  Linux version.
+   Copyright (C) 1997-2018 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -16,22 +17,41 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <sys/ustat.h>
-#include <sys/sysmacros.h>
+#include <shlib-compat.h>
 
-#include <sysdep.h>
-#include <sys/syscall.h>
+/* This deprecated syscall is no longer used (replaced with fstat).  */
+#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_28)
 
-int
-ustat (dev_t dev, struct ustat *ubuf)
-{
-  unsigned long long int k_dev;
+# include <sysdep.h>
+# include <errno.h>
+
+# ifndef DEV_TO_KDEV
+#  define DEV_TO_KDEV(__dev)					\
+  ({								\
+    unsigned long long int k_dev;				\
+    k_dev = dev & ((1ULL << 32) - 1);				\
+    if (k_dev != dev)						\
+     return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);		\
+    (unsigned int) k_dev;					\
+  })
+# endif
 
-  /* We must convert the value to dev_t type used by the kernel.  */
-  k_dev =  dev & ((1ULL << 32) - 1);
-  if (k_dev != dev)
-    return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
+struct ustat
+{
+  __daddr_t f_tfree;         /* Number of free blocks.  */
+  __ino_t f_tinode;          /* Number of free inodes.  */
+  char f_fname[6];
+  char f_fpack[6];
+};
 
-  return INLINE_SYSCALL (ustat, 2, (unsigned int) k_dev, ubuf);
+int
+__old_ustat (dev_t dev, struct ustat *ubuf)
+{
+# ifdef __NR_ustat
+  return INLINE_SYSCALL_CALL (ustat, DEV_TO_KDEV (dev), ubuf);
+# else
+  return INLINE_SYSCALL_ERROR_RETURN_VALUE (ENOSYS);
+# endif
 }
+compat_symbol (libc, __old_ustat, ustat, GLIBC_2_0);
+#endif /* SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_28)  */
-- 
2.7.4