include/linux/ceph/pagelist.h

   1 #ifndef __FS_CEPH_PAGELIST_H
   2 #define __FS_CEPH_PAGELIST_H
   3
   4 #include <linux/list.h>
   5 #include <linux/atomic.h>
   6
   7 struct ceph_pagelist {
   8         struct list_head head;
   9         void *mapped_tail;
  10         size_t length;
  11         size_t room;
  12         struct list_head free_list;
  13         size_t num_pages_free;
  14         atomic_t refcnt;
  15 };
  16
  17 struct ceph_pagelist_cursor {
  18         struct ceph_pagelist *pl;   /* pagelist, for error checking */
  19         struct list_head *page_lru; /* page in list */
  20         size_t room;                /* room remaining to reset to */
  21 };
  22
  23 static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
  24 {
  25         INIT_LIST_HEAD(&pl->head);
  26         pl->mapped_tail = NULL;
  27         pl->length = 0;
  28         pl->room = 0;
  29         INIT_LIST_HEAD(&pl->free_list);
  30         pl->num_pages_free = 0;
  31         atomic_set(&pl->refcnt, 1);
  32 }
  33
  34 extern void ceph_pagelist_release(struct ceph_pagelist *pl);
  35
  36 extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
  37
  38 extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
  39
  40 extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
  41
  42 extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
  43                                      struct ceph_pagelist_cursor *c);
  44
  45 extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
  46                                   struct ceph_pagelist_cursor *c);
  47
  48 static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
  49 {
  50         __le64 ev = cpu_to_le64(v);
  51         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  52 }
  53 static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)
  54 {
  55         __le32 ev = cpu_to_le32(v);
  56         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  57 }
  58 static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)
  59 {
  60         __le16 ev = cpu_to_le16(v);
  61         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  62 }
  63 static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)
  64 {
  65         return ceph_pagelist_append(pl, &v, 1);
  66 }
  67 static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,
  68                                               char *s, size_t len)
  69 {
  70         int ret = ceph_pagelist_encode_32(pl, len);
  71         if (ret)
  72                 return ret;
  73         if (len)
  74                 return ceph_pagelist_append(pl, s, len);
  75         return 0;
  76 }
  77
  78 #endif