From 1c710c896eb461895d3c399e15bb5f20b39c9073 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 8 May 2007 00:33:25 -0700 Subject: utimensat implementation 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 #include #include #include #include #include #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 Cc: Alexey Dobriyan Cc: Michael Kerrisk Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/utimes.c | 162 ++++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 102 insertions(+), 60 deletions(-) (limited to 'fs/utimes.c') diff --git a/fs/utimes.c b/fs/utimes.c index 99cf2cb11fe..480f7c8c29d 100644 --- a/fs/utimes.c +++ b/fs/utimes.c @@ -1,8 +1,10 @@ #include +#include #include #include #include #include +#include #include #include #include @@ -20,54 +22,18 @@ * must be owner or have write permission. * Else, update from *times, must be owner or super user. */ -asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) +asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times) { - int error; - struct nameidata nd; - struct inode * inode; - struct iattr newattrs; + struct timespec tv[2]; - error = user_path_walk(filename, &nd); - if (error) - goto out; - inode = nd.dentry->d_inode; - - error = -EROFS; - if (IS_RDONLY(inode)) - goto dput_and_out; - - /* Don't worry, the checks are done in inode_change_ok() */ - newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; if (times) { - error = -EPERM; - if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) - goto dput_and_out; - - error = get_user(newattrs.ia_atime.tv_sec, ×->actime); - newattrs.ia_atime.tv_nsec = 0; - if (!error) - error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); - newattrs.ia_mtime.tv_nsec = 0; - if (error) - goto dput_and_out; - - newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; - } else { - error = -EACCES; - if (IS_IMMUTABLE(inode)) - goto dput_and_out; - - if (current->fsuid != inode->i_uid && - (error = vfs_permission(&nd, MAY_WRITE)) != 0) - goto dput_and_out; + if (get_user(tv[0].tv_sec, ×->actime) || + get_user(tv[1].tv_sec, ×->modtime)) + return -EFAULT; + tv[0].tv_nsec = 0; + tv[1].tv_nsec = 0; } - mutex_lock(&inode->i_mutex); - error = notify_change(nd.dentry, &newattrs); - mutex_unlock(&inode->i_mutex); -dput_and_out: - path_release(&nd); -out: - return error; + return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0); } #endif @@ -76,18 +42,38 @@ out: * must be owner or have write permission. * Else, update from *times, must be owner or super user. */ -long do_utimes(int dfd, char __user *filename, struct timeval *times) +long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags) { int error; struct nameidata nd; - struct inode * inode; + struct dentry *dentry; + struct inode *inode; struct iattr newattrs; + struct file *f = NULL; - error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); - - if (error) + error = -EINVAL; + if (flags & ~AT_SYMLINK_NOFOLLOW) goto out; - inode = nd.dentry->d_inode; + + if (filename == NULL && dfd != AT_FDCWD) { + error = -EINVAL; + if (flags & AT_SYMLINK_NOFOLLOW) + goto out; + + error = -EBADF; + f = fget(dfd); + if (!f) + goto out; + dentry = f->f_path.dentry; + } else { + error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd); + if (error) + goto out; + + dentry = nd.dentry; + } + + inode = dentry->d_inode; error = -EROFS; if (IS_RDONLY(inode)) @@ -100,11 +86,21 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times) if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) goto dput_and_out; - newattrs.ia_atime.tv_sec = times[0].tv_sec; - newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000; - newattrs.ia_mtime.tv_sec = times[1].tv_sec; - newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000; - newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; + if (times[0].tv_nsec == UTIME_OMIT) + newattrs.ia_valid &= ~ATTR_ATIME; + else if (times[0].tv_nsec != UTIME_NOW) { + newattrs.ia_atime.tv_sec = times[0].tv_sec; + newattrs.ia_atime.tv_nsec = times[0].tv_nsec; + newattrs.ia_valid |= ATTR_ATIME_SET; + } + + if (times[1].tv_nsec == UTIME_OMIT) + newattrs.ia_valid &= ~ATTR_MTIME; + else if (times[1].tv_nsec != UTIME_NOW) { + newattrs.ia_mtime.tv_sec = times[1].tv_sec; + newattrs.ia_mtime.tv_nsec = times[1].tv_nsec; + newattrs.ia_valid |= ATTR_MTIME_SET; + } } else { error = -EACCES; if (IS_IMMUTABLE(inode)) @@ -115,21 +111,67 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times) goto dput_and_out; } mutex_lock(&inode->i_mutex); - error = notify_change(nd.dentry, &newattrs); + error = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); dput_and_out: - path_release(&nd); + if (f) + fput(f); + else + path_release(&nd); out: return error; } +asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags) +{ + struct timespec tstimes[2]; + + if (utimes) { + if (copy_from_user(&tstimes, utimes, sizeof(tstimes))) + return -EFAULT; + if ((tstimes[0].tv_nsec == UTIME_OMIT || + tstimes[0].tv_nsec == UTIME_NOW) && + tstimes[0].tv_sec != 0) + return -EINVAL; + if ((tstimes[1].tv_nsec == UTIME_OMIT || + tstimes[1].tv_nsec == UTIME_NOW) && + tstimes[1].tv_sec != 0) + return -EINVAL; + + /* Nothing to do, we must not even check the path. */ + if (tstimes[0].tv_nsec == UTIME_OMIT && + tstimes[1].tv_nsec == UTIME_OMIT) + return 0; + } + + return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags); +} + asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) { struct timeval times[2]; + struct timespec tstimes[2]; + + if (utimes) { + if (copy_from_user(×, utimes, sizeof(times))) + return -EFAULT; + + /* This test is needed to catch all invalid values. If we + would test only in do_utimes we would miss those invalid + values truncated by the multiplication with 1000. Note + that we also catch UTIME_{NOW,OMIT} here which are only + valid for utimensat. */ + if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 || + times[1].tv_usec >= 1000000 || times[1].tv_usec < 0) + return -EINVAL; + + tstimes[0].tv_sec = times[0].tv_sec; + tstimes[0].tv_nsec = 1000 * times[0].tv_usec; + tstimes[1].tv_sec = times[1].tv_sec; + tstimes[1].tv_nsec = 1000 * times[1].tv_usec; + } - if (utimes && copy_from_user(×, utimes, sizeof(times))) - return -EFAULT; - return do_utimes(dfd, filename, utimes ? times : NULL); + return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0); } asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) -- cgit v1.2.3-18-g5258