incomplete changes for sys_write/sys_close

tasks/fs0/src/memfs/vnode.c

@@ -254,6 +254,10 @@ int memfs_vnode_mknod(struct vnode *v, char *dirname, unsigned int mode)
 	strncpy((char *)memfsd->name, dirname, MEMFS_DNAME_MAX);
 	memfsd->name[MEMFS_DNAME_MAX - 1] = '\0';
 
+	BUG(); /* FIXME: Fix this issue. */
+	/* Write the updated directory buffer back to disk */
+	v->fops.write(v, 0, 1, v->dirbuf.buffer);
+
 	/* Update parent vnode */
 	v->size += sizeof(*memfsd);
 

tasks/fs0/src/syscalls.c

@@ -111,6 +111,19 @@ int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
 	return 0;
 }
 
+int sys_close(l4id_t sender, int fd)
+{
+	struct vnode *v;
+
+	/* Get the task */
+	BUG_ON(!(task = find_task(sender)));
+
+	/* Lookup vnode */
+	if (!(v = vfs_lookup_byvnum(vfs_root.pivot->sb, vnum)))
+		return -EINVAL; /* No such vnode */
+
+}
+
 int sys_mkdir(l4id_t sender, const char *pathname, unsigned int mode)
 {
 	struct tcb *task;

tasks/fs0/src/vfs.c

@@ -59,16 +59,24 @@ struct vnode *vfs_lookup_byvnum(struct superblock *sb, unsigned long vnum)
  */
 struct vnode *vfs_lookup_bypath(struct tcb *task, char *path)
 {
-	/* If it's the root or current dir, we already got it. */
+	struct vnode *vnstart;
+
+	/* Is it the root or current directory? If so, we already got it. */
 	if (!strcmp(path, "/"))
 		return task->rootdir;
 	if (!strcmp(path, "."))
 		return task->curdir;
 
+	/* Do we start from root or curdir? */
+	if (path[0] == '/')
+		vnstart = task->rootdir;
+	else
+		vnstart = task->curdir;
+
 	/*
 	 * This does vfs cache + fs lookup.
 	 */
-	return generic_vnode_lookup(task->rootdir, path);
+	return generic_vnode_lookup(vnstart, path);
 }
 
 int vfs_mount_root(struct superblock *sb)

tasks/mm0/src/file.c

@@ -145,8 +145,8 @@ struct page *find_page(struct vm_file *f, unsigned long pfn)
 }
 
 /*
- * This reads-in a range of pages from a file just like a page fault,
+ * This reads-in a range of pages from a file and populates the page cache
- * but its not in the page fault path.
+ * just like a page fault, but its not in the page fault path.
  */
 int read_file_pages(struct vm_file *vmfile, unsigned long pfn_start,
 		    unsigned long pfn_end)
@@ -192,8 +192,8 @@ int sys_read(l4id_t sender, int fd, void *buf, int count)
 {
 	unsigned long foff_pfn_start, foff_pfn_end;
 	struct vm_file *vmfile;
-	struct tcb *t;
 	unsigned long cursor;
+	struct tcb *t;
 	int err;
 
 	BUG_ON(!(t = find_task(sender)));
@@ -215,9 +215,8 @@ int sys_read(l4id_t sender, int fd, void *buf, int count)
 	 * FIXME: If vmfiles are mapped contiguously on mm0, then these reads
 	 * can be implemented as a straightforward copy as below.
 	 *
-	 * The problem is that in-memrory file pages are usually non-contiguous.
+	 * The problem is that in-memory file pages are usually non-contiguous.
 	 * memcpy(buf, (void *)(vmfile->base + cursor), count);
-	 *
 	 */
 
 	return 0;
@@ -225,6 +224,26 @@ int sys_read(l4id_t sender, int fd, void *buf, int count)
 
 int sys_write(l4id_t sender, int fd, void *buf, int count)
 {
+	unsigned long foff_pfn_start, foff_pfn_end;
+	struct vm_file *vmfile;
+	unsigned long cursor;
+	struct tcb *t;
+	int err;
+
+	BUG_ON(!(t = find_task(sender)));
+
+	/* TODO: Check user buffer and count validity */
+	if (fd < 0 || fd > TASK_OFILES_MAX)
+		return -EINVAL;
+
+	vmfile = t->fd[fd].vmfile;
+	cursor = t->fd[fd].cursor;
+
+	foff_pfn_start = __pfn(cursor);
+	foff_pfn_end = __pfn(page_align_up(cursor + count));
+
+	if ((err =  write_file_pages(vmfile, foff_pfn_start, foff_pfn_end) < 0))
+		return err;
 
 	return 0;
 }