mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![]() Implement utimensat(2) which is an extension to futimesat(2) in that it a) supports nano-second resolution for the timestamps b) allows to selectively ignore the atime/mtime value c) allows to selectively use the current time for either atime or mtime d) supports changing the atime/mtime of a symlink itself along the lines of the BSD lutimes(3) functions For this change the internally used do_utimes() functions was changed to accept a timespec time value and an additional flags parameter. Additionally the sys_utime function was changed to match compat_sys_utime which already use do_utimes instead of duplicating the work. Also, the completely missing futimensat() functionality is added. We have such a function in glibc but we have to resort to using /proc/self/fd/* which not everybody likes (chroot etc). Test application (the syscall number will need per-arch editing): #include <errno.h> #include <fcntl.h> #include <time.h> #include <sys/time.h> #include <stddef.h> #include <syscall.h> #define __NR_utimensat 280 #define UTIME_NOW ((1l << 30) - 1l) #define UTIME_OMIT ((1l << 30) - 2l) int main(void) { int status = 0; int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666); if (fd == -1) error (1, errno, "failed to create test file \"ttt\""); struct stat64 st1; if (fstat64 (fd, &st1) != 0) error (1, errno, "fstat failed"); struct timespec t[2]; t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); struct stat64 st2; if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0] = st1.st_atim; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_OMIT; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("atim not set"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim changed from zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 0; t[0].tv_nsec = UTIME_OMIT; t[1] = st1.st_mtim; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("mtim changed from original time"); status = 1; } if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec || st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec) { puts ("mtim not set"); status = 1; } if (status != 0) goto out; sleep (2); t[0].tv_sec = 0; t[0].tv_nsec = UTIME_NOW; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_NOW; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); struct timeval tv; gettimeofday(&tv,NULL); if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec || st2.st_atim.tv_sec > tv.tv_sec) { puts ("atim not set to NOW"); status = 1; } if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec || st2.st_mtim.tv_sec > tv.tv_sec) { puts ("mtim not set to NOW"); status = 1; } if (symlink ("ttt", "tttsym") != 0) error (1, errno, "cannot create symlink"); t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0) error (1, errno, "utimensat failed"); if (lstat64 ("tttsym", &st2) != 0) error (1, errno, "lstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("symlink atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("symlink mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 1; t[0].tv_nsec = 0; t[1].tv_sec = 1; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to one"); status = 1; } if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to one"); status = 1; } if (status == 0) puts ("all OK"); out: close (fd); unlink ("ttt"); unlink ("tttsym"); return status; } [akpm@linux-foundation.org: add missing i386 syscall table entry] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Cc: Alexey Dobriyan <adobriyan@openvz.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
---|---|---|
.. | ||
boot | ||
kernel | ||
lib | ||
math-emu | ||
mm | ||
oprofile | ||
defconfig | ||
Kconfig | ||
Kconfig.debug | ||
Makefile |