1 /* Copyright (C) 2003-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <sysdep.h>
21 
22 /* Advice the system about the expected behaviour of the application with
23    respect to the file associated with FD.  */
24 
25 #ifndef __OFF_T_MATCHES_OFF64_T
26 
27 /* Default implementation will use __NR_fadvise64 with expected argument
28    positions (for instance i386 and powerpc32 that uses __ALIGNMENT_ARG).
29 
30    Second option will be used by arm which define __NR_arm_fadvise64_64
31    (redefined to __NR_fadvise64_64 in kernel-features.h) that behaves as
32    __NR_fadvise64_64 (without the aligment argument required for the ABI).
33 
34    Third option will be used by mips o32.  Mips will use a 7 argument
35    syscall with __NR_fadvise64.
36 
37    s390 implements fadvice64_64 using a specific struct with arguments
38    packed inside.  This is the only implementation handled in arch-specific
39    code.  */
40 
41 int
posix_fadvise(int fd,off_t offset,off_t len,int advise)42 posix_fadvise (int fd, off_t offset, off_t len, int advise)
43 {
44 # if defined (__NR_fadvise64) && !defined (__ASSUME_FADVISE64_AS_64_64)
45   int ret = INTERNAL_SYSCALL_CALL (fadvise64, fd,
46 				   __ALIGNMENT_ARG SYSCALL_LL (offset),
47 				   len, advise);
48 # else
49 #  ifdef __ASSUME_FADVISE64_64_6ARG
50   int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, fd, advise,
51 				   SYSCALL_LL (offset), SYSCALL_LL (len));
52 #  else
53 
54 #   ifndef __NR_fadvise64_64
55 #    define __NR_fadvise64_64 __NR_fadvise64
56 #   endif
57 
58   int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, fd,
59 				   __ALIGNMENT_ARG SYSCALL_LL (offset),
60 				   SYSCALL_LL (len), advise);
61 #  endif
62 # endif
63   if (INTERNAL_SYSCALL_ERROR_P (ret))
64     return INTERNAL_SYSCALL_ERRNO (ret);
65   return 0;
66 }
67 #endif /* __OFF_T_MATCHES_OFF64_T  */
68