[PATCH] Create fs/utimes.c

* fs/open.c is getting bit crowdy
* preparation to lutimes(2)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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, &times->actime);
+		newattrs.ia_atime.tv_nsec = 0;
+		if (!error)
+			error = get_user(newattrs.ia_mtime.tv_sec, &times->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(&times, 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);
+}