[net-next-2.6.git] / net / ceph / pagelist.c


#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/ceph/pagelist.h>

static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl)
{
	struct page *page = list_entry(pl->head.prev, struct page,
				       lru);
	kunmap(page);
}

int ceph_pagelist_release(struct ceph_pagelist *pl)
{
	if (pl->mapped_tail)
		ceph_pagelist_unmap_tail(pl);

	while (!list_empty(&pl->head)) {
		struct page *page = list_first_entry(&pl->head, struct page,
						     lru);
		list_del(&page->lru);
		__free_page(page);
	}
	return 0;
}
EXPORT_SYMBOL(ceph_pagelist_release);

static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
{
	struct page *page = __page_cache_alloc(GFP_NOFS);
	if (!page)
		return -ENOMEM;
	pl->room += PAGE_SIZE;
	list_add_tail(&page->lru, &pl->head);
	if (pl->mapped_tail)
		ceph_pagelist_unmap_tail(pl);
	pl->mapped_tail = kmap(page);
	return 0;
}

int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len)
{
	while (pl->room < len) {
		size_t bit = pl->room;
		int ret;

		memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK),
		       buf, bit);
		pl->length += bit;
		pl->room -= bit;
		buf += bit;
		len -= bit;
		ret = ceph_pagelist_addpage(pl);
		if (ret)
			return ret;
	}

	memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len);
	pl->length += len;
	pl->room -= len;
	return 0;
}
EXPORT_SYMBOL(ceph_pagelist_append);
Commit	Line	Data
58bb3b37	1
3d14c5d2	2	#include <linux/module.h>
5a0e3ad6	3	#include <linux/gfp.h>
58bb3b37 SW	4	#include <linux/pagemap.h>
58bb3b37 SW	5	#include <linux/highmem.h>
3d14c5d2	6	#include <linux/ceph/pagelist.h>
58bb3b37	7
3d4401d9 YS	8	static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl)
	9	{
	10	struct page *page = list_entry(pl->head.prev, struct page,
	11	lru);
	12	kunmap(page);
	13	}
	14
58bb3b37 SW	15	int ceph_pagelist_release(struct ceph_pagelist *pl)
	16	{
	17	if (pl->mapped_tail)
3d4401d9 YS	18	ceph_pagelist_unmap_tail(pl);
3d4401d9 YS	19
58bb3b37 SW	20	while (!list_empty(&pl->head)) {
	21	struct page *page = list_first_entry(&pl->head, struct page,
	22	lru);
	23	list_del(&page->lru);
	24	__free_page(page);
	25	}
	26	return 0;
	27	}
3d14c5d2	28	EXPORT_SYMBOL(ceph_pagelist_release);
58bb3b37 SW	29
	30	static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
	31	{
31459fe4	32	struct page *page = __page_cache_alloc(GFP_NOFS);
58bb3b37 SW	33	if (!page)
	34	return -ENOMEM;
	35	pl->room += PAGE_SIZE;
	36	list_add_tail(&page->lru, &pl->head);
	37	if (pl->mapped_tail)
3d4401d9	38	ceph_pagelist_unmap_tail(pl);
58bb3b37 SW	39	pl->mapped_tail = kmap(page);
	40	return 0;
	41	}
	42
68b4476b	43	int ceph_pagelist_append(struct ceph_pagelist pl, const void buf, size_t len)
58bb3b37 SW	44	{
	45	while (pl->room < len) {
	46	size_t bit = pl->room;
	47	int ret;
	48
	49	memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK),
	50	buf, bit);
	51	pl->length += bit;
	52	pl->room -= bit;
	53	buf += bit;
	54	len -= bit;
	55	ret = ceph_pagelist_addpage(pl);
	56	if (ret)
	57	return ret;
	58	}
	59
	60	memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len);
	61	pl->length += len;
	62	pl->room -= len;
	63	return 0;
	64	}
3d14c5d2	65	EXPORT_SYMBOL(ceph_pagelist_append);