close syscall

src/sys/syscalls/close.c

@@ -0,0 +1,46 @@
+#include <kernel/syscalls.h>
+#include <kernel/fd.h>
+#include <arch/cls.h>
+#include <kernel/vfs.h>
+#include <arch/spinlock.h>
+
+syscallret syscall_close(int ifd){
+
+        syscallret retv;
+        retv.ret = -1;
+
+        proc_t* proc = arch_getcls()->thread->proc;
+
+        fd_t* fd = proc->fds + ifd;
+
+        spinlock_acquire(&proc->fdlock);
+
+        if(proc->fdcount <= ifd || fd->node == NULL || (fd->flags & FD_FLAGS_READ) == 0){
+                spinlock_release(&proc->fdlock);
+                retv.errno = EBADF;
+                return retv;
+        }
+
+        spinlock_acquire(&fd->lock);
+        spinlock_release(&proc->fdlock);
+	
+	int ret = vfs_close(fd->node);
+	
+	if(ret){
+		retv.errno = ret;
+		goto _ret;
+	}
+
+	// the fd table isn't resized on a close
+	// although that can be added if it becomes an issue
+	
+	fd->node = NULL;
+
+	retv.ret = 0;
+	retv.errno = 0;
+
+	_ret:
+
+	spinlock_release(&fd->lock);
+	return retv;
+}