PM / Wakeup: Show wakeup sources statistics in debugfs
[linux-2.6.git] / fs / ceph / pagelist.c
1
2 #include <linux/gfp.h>
3 #include <linux/pagemap.h>
4 #include <linux/highmem.h>
5
6 #include "pagelist.h"
7
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
15 int ceph_pagelist_release(struct ceph_pagelist *pl)
16 {
17         if (pl->mapped_tail)
18                 ceph_pagelist_unmap_tail(pl);
19
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 }
28
29 static int ceph_pagelist_addpage(struct ceph_pagelist *pl)
30 {
31         struct page *page = __page_cache_alloc(GFP_NOFS);
32         if (!page)
33                 return -ENOMEM;
34         pl->room += PAGE_SIZE;
35         list_add_tail(&page->lru, &pl->head);
36         if (pl->mapped_tail)
37                 ceph_pagelist_unmap_tail(pl);
38         pl->mapped_tail = kmap(page);
39         return 0;
40 }
41
42 int ceph_pagelist_append(struct ceph_pagelist *pl, void *buf, size_t len)
43 {
44         while (pl->room < len) {
45                 size_t bit = pl->room;
46                 int ret;
47
48                 memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK),
49                        buf, bit);
50                 pl->length += bit;
51                 pl->room -= bit;
52                 buf += bit;
53                 len -= bit;
54                 ret = ceph_pagelist_addpage(pl);
55                 if (ret)
56                         return ret;
57         }
58
59         memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len);
60         pl->length += len;
61         pl->room -= len;
62         return 0;
63 }