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Update from Gnulib by running admin/merge-gnulib

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* lib/sys-limits.h: New file.
This commit is contained in:
Paul Eggert
2025-08-02 10:47:03 -07:00
parent 84f1080f67
commit 687d3cb03b
6 changed files with 116 additions and 31 deletions
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66
lib/copy-file-range.c
View File

@@ -21,9 +21,22 @@
#include <errno.h>
#if defined __linux__ && HAVE_COPY_FILE_RANGE
# include <linux/version.h>
# include <sys/utsname.h>
/* Although it can be dicey to use static checks for Linux kernel versions,
due to the dubious practice of building on newer kernels for older ones,
do it here anyway as the buggy kernels are rare (they are all EOLed)
and builders for them are unlikely to use the dubious practice.
Circa 2029 we should remove the old-kernel workarounds entirely. */
# if LINUX_VERSION_CODE < KERNEL_VERSION (5, 3, 0)
# define CHECK_LINUX_KERNEL_VERSION true
# else
# define CHECK_LINUX_KERNEL_VERSION false
# endif
#endif
#include "sys-limits.h"
ssize_t
copy_file_range (int infd, off_t *pinoff,
int outfd, off_t *poutoff,
@@ -31,32 +44,51 @@ copy_file_range (int infd, off_t *pinoff,
{
#undef copy_file_range
#if defined __linux__ && HAVE_COPY_FILE_RANGE
#if HAVE_COPY_FILE_RANGE
bool ok = true;
# if CHECK_LINUX_KERNEL_VERSION
/* The implementation of copy_file_range (which first appeared in
Linux kernel release 4.5) had many issues before release 5.3
<https://lwn.net/Articles/789527/>, so fail with ENOSYS for Linux
kernels 5.2 and earlier.
This workaround, and the configure-time check for Linux, can be
removed when such kernels (released March 2016 through September
2019) are no longer a consideration. As of January 2021, the
furthest-future planned kernel EOL is December 2024 for kernel
release 4.19. */
This workaround can be removed when such kernels (released March
2016 through September 2019) are no longer a consideration.
Although all such kernels have reached EOL, some distros use
older kernels. For example, RHEL 8 uses kernel 4.18 and has an
EOL of 2029. */
static signed char ok;
static signed char kernel_ok;
if (! kernel_ok)
{
struct utsname name;
uname (&name);
char *p = name.release;
kernel_ok = ((p[1] != '.' || '5' < p[0]
|| (p[0] == '5' && (p[3] != '.' || '2' < p[2])))
? 1 : -1);
}
if (! ok)
{
struct utsname name;
uname (&name);
char *p = name.release;
ok = ((p[1] != '.' || '5' < p[0]
|| (p[0] == '5' && (p[3] != '.' || '2' < p[2])))
? 1 : -1);
}
if (kernel_ok < 0)
ok = false;
# endif
if (ok)
{
# if defined __GLIBC__ && ! (2 < __GLIBC__ + (43 <= __GLIBC_MINOR__))
/* Work around glibc bug 33245
<https://sourceware.org/bugzilla/show_bug.cgi?id=33245>.
This bug is present in glibc 2.42 (2025) and fixed in 2.43,
so this workaround, and the configure-time check for glibc,
can be removed once glibc 2.42 and earlier is no longer a
consideration. Perhaps in 2040. */
if (SYS_BUFSIZE_MAX < length)
length = SYS_BUFSIZE_MAX;
# endif
if (0 < ok)
return copy_file_range (infd, pinoff, outfd, poutoff, length, flags);
}
#endif
/* There is little need to emulate copy_file_range with read+write,

2
lib/gnulib.mk.in
View File

@@ -1799,6 +1799,8 @@ ifneq (,$(GL_COND_OBJ_COPY_FILE_RANGE_CONDITION))
libgnu_a_SOURCES += copy-file-range.c
endif
EXTRA_DIST += sys-limits.h
endif
## end gnulib module copy-file-range

42
lib/sys-limits.h Normal file
View File

@@ -0,0 +1,42 @@
/* System call limits
Copyright 2018-2025 Free Software Foundation, Inc.
This file 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.
This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
#ifndef _GL_SYS_LIMITS_H
#define _GL_SYS_LIMITS_H
#include <limits.h>
/* Maximum number of bytes to read or write in a single system call.
This can be useful for system calls like sendfile on GNU/Linux,
which do not handle more than MAX_RW_COUNT bytes correctly.
The Linux kernel MAX_RW_COUNT is at least INT_MAX >> 20 << 20,
where the 20 comes from the Hexagon port with 1 MiB pages; use that
as an approximation, as the exact value may not be available to us.
Using this also works around a serious Linux bug before 2.6.16; see
<https://bugzilla.redhat.com/show_bug.cgi?id=612839>.
Using this also works around a Tru64 5.1 bug, where attempting
to read INT_MAX bytes fails with errno == EINVAL. See
<https://lists.gnu.org/r/bug-gnu-utils/2002-04/msg00010.html>.
Using this is likely to work around similar bugs in other operating
systems. */
enum { SYS_BUFSIZE_MAX = INT_MAX >> 20 << 20 };
#endif