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#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include "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;
}
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;
}
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