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linux-next/include/linux/ceph/pagelist.h
Yan, Zheng e4339d28f6 libceph: reference counting pagelist
this allow pagelist to present data that may be sent multiple times.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2014-10-14 12:56:48 -07:00

79 lines
2.0 KiB
C

#ifndef __FS_CEPH_PAGELIST_H
#define __FS_CEPH_PAGELIST_H
#include <linux/list.h>
#include <linux/atomic.h>
struct ceph_pagelist {
struct list_head head;
void *mapped_tail;
size_t length;
size_t room;
struct list_head free_list;
size_t num_pages_free;
atomic_t refcnt;
};
struct ceph_pagelist_cursor {
struct ceph_pagelist *pl; /* pagelist, for error checking */
struct list_head *page_lru; /* page in list */
size_t room; /* room remaining to reset to */
};
static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
{
INIT_LIST_HEAD(&pl->head);
pl->mapped_tail = NULL;
pl->length = 0;
pl->room = 0;
INIT_LIST_HEAD(&pl->free_list);
pl->num_pages_free = 0;
atomic_set(&pl->refcnt, 1);
}
extern void ceph_pagelist_release(struct ceph_pagelist *pl);
extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
struct ceph_pagelist_cursor *c);
extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
struct ceph_pagelist_cursor *c);
static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
{
__le64 ev = cpu_to_le64(v);
return ceph_pagelist_append(pl, &ev, sizeof(ev));
}
static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)
{
__le32 ev = cpu_to_le32(v);
return ceph_pagelist_append(pl, &ev, sizeof(ev));
}
static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)
{
__le16 ev = cpu_to_le16(v);
return ceph_pagelist_append(pl, &ev, sizeof(ev));
}
static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)
{
return ceph_pagelist_append(pl, &v, 1);
}
static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,
char *s, size_t len)
{
int ret = ceph_pagelist_encode_32(pl, len);
if (ret)
return ret;
if (len)
return ceph_pagelist_append(pl, s, len);
return 0;
}
#endif