readahead.c 1.6 KB

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  1. /* Provide kernel hint to read ahead.
  2. Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  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. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #include <errno.h>
  17. #include <fcntl.h>
  18. #include <sys/types.h>
  19. #include <sys/syscall.h>
  20. #include <bits/wordsize.h>
  21. #ifdef __UCLIBC_HAS_LFS__
  22. #include <_lfs_64.h>
  23. #ifdef __NR_readahead
  24. # define __NR___readahead __NR_readahead
  25. # if __WORDSIZE == 64
  26. static inline _syscall3(ssize_t, __readahead, int, fd,
  27. off_t, offset, size_t, count);
  28. ssize_t readahead(int fd, off_t offset, size_t count)
  29. {
  30. return __readahead(fd, offset, count);
  31. }
  32. # else
  33. static inline _syscall4(ssize_t, __readahead, int, fd,
  34. off_t, high_offset, off_t, low_offset, size_t, count);
  35. ssize_t readahead(int fd, off64_t offset, size_t count)
  36. {
  37. return __readahead(fd, (off_t) (offset >> 32), (off_t) (offset & 0xffffffff), count);
  38. }
  39. # endif
  40. #endif
  41. #endif /* __UCLIBC_HAS_LFS__ */