kernel: utime syscall

kernel-src/sys/syscalls/utime.c

@@ -0,0 +1,76 @@
+#include <kernel/syscalls.h>
+#include <kernel/alloc.h>
+#include <kernel/timekeeper.h>
+
+syscallret_t syscall_utimensat(context_t *, int fd, char *upath, timespec_t uts[2], int flags) {
+	// TODO
+	// uts -> NULL -> current time
+	// upath -> NULL -> dirfd points to vnode 
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	timespec_t ts[2];
+	if (uts == NULL)
+		memcpy(ts, uts, sizeof(timespec_t) * 2);
+	else
+		ts[0] = ts[1] = timekeeper_time();
+
+	vnode_t *node = NULL;
+	vnode_t *dirnode = NULL;
+	file_t *file = NULL;
+	char *path = NULL;
+
+	if (upath == NULL) {
+		// operation is done on the file pointed to by fd
+		file_t *file = fd_get(fd);
+		if (file == NULL) {
+			ret.errno = EBADF;
+			goto cleanup;
+		}
+
+		node = file->vnode;
+		VOP_HOLD(node);
+		fd_release(file);
+	} else {
+		// operation is done on the file pointed to by the path relative to fd
+		path = alloc(strlen(upath) + 1);
+		if (path == NULL) {
+			ret.errno = ENOMEM;
+			goto cleanup;
+		}
+
+		strcpy(path, upath);
+		ret.errno = dirfd_enter(path, fd, &file, &dirnode);
+		if (ret.errno)
+			goto cleanup;
+
+		ret.errno = vfs_lookup(&node, dirnode, path, NULL, (flags & AT_SYMLINK_NOFOLLOW) ? VFS_LOOKUP_NOLINK : 0);
+		if (ret.errno)
+			goto cleanup;
+	}
+
+	// XXX race condition with other system calls
+	vattr_t attr;
+	ret.errno = VOP_GETATTR(node, &attr, &_cpu()->thread->proc->cred);
+	if (ret.errno)
+		goto cleanup;
+
+	attr.atime = ts[0];
+	attr.mtime = ts[1];
+
+	ret.errno = VOP_SETATTR(node, &attr, &_cpu()->thread->proc->cred);
+	ret.ret = ret.errno ? -1 : 0;
+
+	cleanup:
+	if (node)
+		VOP_RELEASE(node);
+
+	if (dirnode)
+		dirfd_leave(dirnode, file);
+
+	if (path)
+		free(path);
+
+	return ret;
+}