pagelist.h

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#ifndef __FS_CEPH_PAGELIST_H
#define __FS_CEPH_PAGELIST_H

#include <linux/list.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;
};

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;
}

extern int 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