scheduler: getcwd, getroot, and initialise process cwd and root to vfsroot

kernel-src/include/kernel/scheduler.h

@@ -50,6 +50,7 @@ typedef struct proc_t {
 	int flags;
 	vnode_t *cwd;
 	vnode_t *root;
+	spinlock_t nodeslock;
 } proc_t;
 
 #include <arch/cpu.h>
@@ -64,6 +65,9 @@ void sched_preparesleep(bool interruptible);
 void sched_wakeup(thread_t *thread, int reason);
 int sched_sleep();
 proc_t *sched_newproc();
+vnode_t *sched_getcwd();
+vnode_t *sched_getroot();
 thread_t *sched_newthread(void *ip, size_t kstacksize, int priority, proc_t *proc, void *ustack);
 
+
 #endif

kernel-src/sys/scheduler.c

@@ -40,6 +40,7 @@ proc_t *sched_newproc() {
 	proc->threadtablesize = 1;
 	proc->runningthreadcount = 1;
 	SPINLOCK_INIT(proc->lock);
+	SPINLOCK_INIT(proc->nodeslock);
 	proc->fdcount = 3;
 	proc->fdfirst = 3;
 	SPINLOCK_INIT(proc->fdlock);
@@ -273,6 +274,27 @@ void sched_wakeup(thread_t *thread, int reason) {
 	interrupt_set(intstate);
 }
 
+static vnode_t *getnodeslock(vnode_t **addr) {
+	proc_t *proc = _cpu()->thread->proc;
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->nodeslock);
+	vnode_t *vnode = *addr;
+	VOP_HOLD(vnode);
+	spinlock_release(&proc->nodeslock);
+	interrupt_set(intstatus);
+	return vnode;
+}
+
+vnode_t *sched_getcwd() {
+	proc_t *proc = _cpu()->thread->proc;
+	return getnodeslock(&proc->cwd);
+}
+
+vnode_t *sched_getroot() {
+	proc_t *proc = _cpu()->thread->proc;
+	return getnodeslock(&proc->root);
+}
+
 static void timerhook(void *private, context_t *context) {
 	thread_t* current = _cpu()->thread;
 
@@ -360,6 +382,18 @@ void sched_runinit() {
 		__assert(interpinterp == NULL);
 	}
 
+	vnode_t *stdinvnode;
+	__assert(vfs_open(vfsroot, "/dev/console", V_FFLAGS_READ, &stdinvnode) == 0);
+	vnode_t *stdoutnode;
+	__assert(vfs_open(vfsroot, "/dev/console", V_FFLAGS_WRITE, &stdoutnode) == 0);
+	vnode_t *stderrnode;
+	__assert(vfs_open(vfsroot, "/dev/console", V_FFLAGS_WRITE, &stderrnode) == 0);
+
+	proc->cwd = vfsroot;
+	VOP_HOLD(vfsroot);
+	proc->root = vfsroot;
+	VOP_HOLD(vfsroot);
+
 	char *argv = {NULL};
 	char *envp = {NULL};