diff options
Diffstat (limited to 'fs/utimes.c')
| -rw-r--r-- | fs/utimes.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/fs/utimes.c b/fs/utimes.c new file mode 100644 index 0000000..1bcd852f --- /dev/null +++ b/fs/utimes.c @@ -0,0 +1,137 @@ +#include <linux/compiler.h> +#include <linux/fs.h> +#include <linux/linkage.h> +#include <linux/namei.h> +#include <linux/utime.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> + +#ifdef __ARCH_WANT_SYS_UTIME + +/* + * sys_utime() can be implemented in user-level using sys_utimes(). + * Is this for backwards compatibility? If so, why not move it + * into the appropriate arch directory (for those architectures that + * need it). + */ + +/* If times==NULL, set access and modification to current time, + * 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) +{ + int error; + struct nameidata nd; + struct inode * inode; + struct iattr newattrs; + + 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; + } + 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; +} + +#endif + +/* If times==NULL, set access and modification to current time, + * 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) +{ + int error; + struct nameidata nd; + struct inode * inode; + struct iattr newattrs; + + error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &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; + + 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; + } 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; + } + 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; +} + +asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) +{ + struct timeval times[2]; + + if (utimes && copy_from_user(×, utimes, sizeof(times))) + return -EFAULT; + return do_utimes(dfd, filename, utimes ? times : NULL); +} + +asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) +{ + return sys_futimesat(AT_FDCWD, filename, utimes); +} |
