include/linux/ceph/pagelist.h

   1 #ifndef __FS_CEPH_PAGELIST_H
   2 #define __FS_CEPH_PAGELIST_H
   3
   4 #include <asm/byteorder.h>
   5 #include <linux/atomic.h>
   6 #include <linux/list.h>
   7 #include <linux/types.h>
   8
   9 struct ceph_pagelist {
  10         struct list_head head;
  11         void *mapped_tail;
  12         size_t length;
  13         size_t room;
  14         struct list_head free_list;
  15         size_t num_pages_free;
  16         atomic_t refcnt;
  17 };
  18
  19 struct ceph_pagelist_cursor {
  20         struct ceph_pagelist *pl;   /* pagelist, for error checking */
  21         struct list_head *page_lru; /* page in list */
  22         size_t room;                /* room remaining to reset to */
  23 };
  24
  25 static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
  26 {
  27         INIT_LIST_HEAD(&pl->head);
  28         pl->mapped_tail = NULL;
  29         pl->length = 0;
  30         pl->room = 0;
  31         INIT_LIST_HEAD(&pl->free_list);
  32         pl->num_pages_free = 0;
  33         atomic_set(&pl->refcnt, 1);
  34 }
  35
  36 extern void ceph_pagelist_release(struct ceph_pagelist *pl);
  37
  38 extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
  39
  40 extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
  41
  42 extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
  43
  44 extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
  45                                      struct ceph_pagelist_cursor *c);
  46
  47 extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
  48                                   struct ceph_pagelist_cursor *c);
  49
  50 static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
  51 {
  52         __le64 ev = cpu_to_le64(v);
  53         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  54 }
  55 static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)
  56 {
  57         __le32 ev = cpu_to_le32(v);
  58         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  59 }
  60 static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)
  61 {
  62         __le16 ev = cpu_to_le16(v);
  63         return ceph_pagelist_append(pl, &ev, sizeof(ev));
  64 }
  65 static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)
  66 {
  67         return ceph_pagelist_append(pl, &v, 1);
  68 }
  69 static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,
  70                                               char *s, size_t len)
  71 {
  72         int ret = ceph_pagelist_encode_32(pl, len);
  73         if (ret)
  74                 return ret;
  75         if (len)
  76                 return ceph_pagelist_append(pl, s, len);
  77         return 0;
  78 }
  79
  80 #endif