--- a/cp/fs/Makefile	Tue Apr 26 14:00:24 2011 -0400
+++ b/cp/fs/Makefile	Tue Apr 26 14:01:31 2011 -0400
@@ -1,1 +1,1 @@
-objs-fs := bdev.o edf.o bcache.o
+objs-fs := bdev.o edf.o bcache.o spool.o

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cp/fs/spool.c	Tue Apr 26 14:01:31 2011 -0400
@@ -0,0 +1,146 @@
+/*
+ * (C) Copyright 2007-2011  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
+ *
+ * This file is released under the GPLv2.  See the COPYING file for more
+ * details.
+ */
+
+#include <spool.h>
+#include <buddy.h>
+#include <slab.h>
+
+static LOCK_CLASS(spool_file_lc);
+
+struct spool_file *alloc_spool()
+{
+	struct spool_file *f;
+
+	f = malloc(sizeof(struct spool_file), ZONE_NORMAL);
+	if (!f)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&f->lock, &spool_file_lc);
+	INIT_LIST_HEAD(&f->list);
+	f->recs = 0;
+	f->pages = 0;
+	f->frecoff = 0;
+	f->lrecoff = 0;
+
+	return f;
+}
+
+void free_spool(struct spool_file *f)
+{
+	free(f);
+}
+
+int spool_append_rec(struct spool_file *f, u8 *buf, u16 len)
+{
+	struct list_head new_pages;
+	struct spool_page *spage, *tmp;
+	struct spool_rec *rec;
+	struct page *page;
+	int npages;
+	int loff;
+	int copied;
+	u32 left;
+	u32 rlen;
+	int ret;
+
+	INIT_LIST_HEAD(&new_pages);
+	npages = 0;
+
+	BUG_ON(sizeof(struct spool_rec) != 2);
+
+	mutex_lock(&f->lock);
+
+	left = SPOOL_DATA_SIZE - f->lrecoff;
+	rlen = len + sizeof(struct spool_rec);
+	copied = 0;
+
+	/* try to fill up the last page */
+	if (f->pages && left) {
+		spage = list_last_entry(&f->list, struct spool_page, list);
+		rec = (struct spool_rec*) (spage->data + f->lrecoff);
+
+		switch(left) {
+			case 1:
+				spage->data[f->lrecoff] = len >> 8;
+				copied = 1;
+				loff = SPOOL_DATA_SIZE;
+				break;
+			case 2:
+				rec->len = len;
+				copied = 2;
+				loff = SPOOL_DATA_SIZE;
+				break;
+			default:
+				rec->len = len;
+				memcpy(rec->data, buf, min_t(u32, len, left-2));
+				copied = 2 + min_t(u32, len, left-2);
+				loff = f->lrecoff + copied;
+				break;
+		}
+	}
+
+	BUG_ON(rlen < copied);
+
+	/* we need to allocate space */
+	while (rlen != copied) {
+		page = alloc_pages(0, ZONE_NORMAL);
+		if (!page) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		spage = page_to_addr(page);
+
+		INIT_LIST_HEAD(&spage->list);
+		list_add_tail(&spage->list, &new_pages);
+		npages++;
+
+		rec = (struct spool_rec*) spage->data;
+		left = SPOOL_DATA_SIZE;
+
+		switch(copied) {
+			case 0:
+				/* nothing was copied */
+				rec->len = len;
+				memcpy(rec->data, buf, min_t(u32, len, left-2));
+				loff = 2 + min_t(u32, len, left-2);
+				break;
+			case 1:
+				/* half of the length was copied */
+				spage->data[0] = len & 0xff;
+				rec = (struct spool_rec*) (spage->data - 1);
+				memcpy(rec->data, buf, min_t(u32, len, left-1));
+				loff = 1 + min_t(u32, len, left-1);
+				break;
+			default:
+				/* the length and maybe some data were copied */
+				memcpy(spage, buf-copied+2, min(rlen-copied, left));
+				loff = min(rlen-copied, left);
+				break;
+		}
+
+		copied += loff;
+	}
+
+	list_splice_tail(&new_pages, &f->list);
+
+	f->pages += npages;
+	f->recs++;
+	f->lrecoff = loff;
+
+	mutex_unlock(&f->lock);
+	return 0;
+
+err:
+	mutex_unlock(&f->lock);
+
+	list_for_each_entry_safe(spage, tmp, &new_pages, list)
+		free_pages(spage, 0);
+
+	return ret;
+
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cp/include/spool.h	Tue Apr 26 14:01:31 2011 -0400
@@ -0,0 +1,39 @@
+/*
+ * (C) Copyright 2007-2011  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
+ *
+ * This file is released under the GPLv2.  See the COPYING file for more
+ * details.
+ */
+
+#ifndef __SPOOL_H
+#define __SPOOL_H
+
+#include <list.h>
+#include <mutex.h>
+
+struct spool_rec {
+	u16 len;
+	u8 data[0];
+};
+
+#define SPOOL_DATA_SIZE		(PAGE_SIZE - sizeof(struct list_head))
+struct spool_page {
+	struct list_head list;
+	u8 data[SPOOL_DATA_SIZE];
+};
+
+struct spool_file {
+	mutex_t lock;
+	struct list_head list;
+	u64 recs;
+	u64 pages;
+	u16 frecoff;	/* start of the first record,
+			   offset into first page's data */
+	u16 lrecoff;	/* end of the last record,
+			   offset into last page's data */
+};
+
+extern struct spool_file *alloc_spool();
+extern void free_spool(struct spool_file *f);
+
+#endif