1  /* SPDX-License-Identifier: GPL-2.0 */
2  #ifndef __FS_CEPH_PAGELIST_H
3  #define __FS_CEPH_PAGELIST_H
4  
5  #include <asm/byteorder.h>
6  #include <linux/refcount.h>
7  #include <linux/list.h>
8  #include <linux/types.h>
9  
10  struct ceph_pagelist {
11  	struct list_head head;
12  	void *mapped_tail;
13  	size_t length;
14  	size_t room;
15  	struct list_head free_list;
16  	size_t num_pages_free;
17  	refcount_t refcnt;
18  };
19  
20  struct ceph_pagelist_cursor {
21  	struct ceph_pagelist *pl;   /* pagelist, for error checking */
22  	struct list_head *page_lru; /* page in list */
23  	size_t room;		    /* room remaining to reset to */
24  };
25  
26  struct ceph_pagelist *ceph_pagelist_alloc(gfp_t gfp_flags);
27  
28  extern void ceph_pagelist_release(struct ceph_pagelist *pl);
29  
30  extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
31  
32  extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
33  
34  extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
35  
36  extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
37  				     struct ceph_pagelist_cursor *c);
38  
39  extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
40  				  struct ceph_pagelist_cursor *c);
41  
ceph_pagelist_encode_64(struct ceph_pagelist * pl,u64 v)42  static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
43  {
44  	__le64 ev = cpu_to_le64(v);
45  	return ceph_pagelist_append(pl, &ev, sizeof(ev));
46  }
ceph_pagelist_encode_32(struct ceph_pagelist * pl,u32 v)47  static inline int ceph_pagelist_encode_32(struct ceph_pagelist *pl, u32 v)
48  {
49  	__le32 ev = cpu_to_le32(v);
50  	return ceph_pagelist_append(pl, &ev, sizeof(ev));
51  }
ceph_pagelist_encode_16(struct ceph_pagelist * pl,u16 v)52  static inline int ceph_pagelist_encode_16(struct ceph_pagelist *pl, u16 v)
53  {
54  	__le16 ev = cpu_to_le16(v);
55  	return ceph_pagelist_append(pl, &ev, sizeof(ev));
56  }
ceph_pagelist_encode_8(struct ceph_pagelist * pl,u8 v)57  static inline int ceph_pagelist_encode_8(struct ceph_pagelist *pl, u8 v)
58  {
59  	return ceph_pagelist_append(pl, &v, 1);
60  }
ceph_pagelist_encode_string(struct ceph_pagelist * pl,char * s,u32 len)61  static inline int ceph_pagelist_encode_string(struct ceph_pagelist *pl,
62  					      char *s, u32 len)
63  {
64  	int ret = ceph_pagelist_encode_32(pl, len);
65  	if (ret)
66  		return ret;
67  	if (len)
68  		return ceph_pagelist_append(pl, s, len);
69  	return 0;
70  }
71  
72  #endif
73