xref: /openbmc/linux/fs/smb/client/dfs_cache.h (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
1  /* SPDX-License-Identifier: GPL-2.0 */
2  /*
3   * DFS referral cache routines
4   *
5   * Copyright (c) 2018-2019 Paulo Alcantara <palcantara@suse.de>
6   */
7  
8  #ifndef _CIFS_DFS_CACHE_H
9  #define _CIFS_DFS_CACHE_H
10  
11  #include <linux/nls.h>
12  #include <linux/list.h>
13  #include <linux/uuid.h>
14  #include "cifsglob.h"
15  
16  extern struct workqueue_struct *dfscache_wq;
17  extern atomic_t dfs_cache_ttl;
18  
19  #define DFS_CACHE_TGT_LIST_INIT(var) \
20  	{ .tl_numtgts = 0, .tl_list = LIST_HEAD_INIT((var).tl_list), }
21  
22  #define DFS_CACHE_TGT_LIST(var) \
23  	struct dfs_cache_tgt_list var = DFS_CACHE_TGT_LIST_INIT(var)
24  
25  struct dfs_cache_tgt_list {
26  	int tl_numtgts;
27  	struct list_head tl_list;
28  };
29  
30  struct dfs_cache_tgt_iterator {
31  	char *it_name;
32  	int it_path_consumed;
33  	struct list_head it_list;
34  };
35  
36  int dfs_cache_init(void);
37  void dfs_cache_destroy(void);
38  extern const struct proc_ops dfscache_proc_ops;
39  
40  int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, const struct nls_table *cp,
41  		   int remap, const char *path, struct dfs_info3_param *ref,
42  		   struct dfs_cache_tgt_list *tgt_list);
43  int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
44  			 struct dfs_cache_tgt_list *tgt_list);
45  void dfs_cache_noreq_update_tgthint(const char *path, const struct dfs_cache_tgt_iterator *it);
46  int dfs_cache_get_tgt_referral(const char *path, const struct dfs_cache_tgt_iterator *it,
47  			       struct dfs_info3_param *ref);
48  int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it, char **share,
49  			    char **prefix);
50  char *dfs_cache_canonical_path(const char *path, const struct nls_table *cp, int remap);
51  int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb);
52  void dfs_cache_refresh(struct work_struct *work);
53  
54  static inline struct dfs_cache_tgt_iterator *
dfs_cache_get_next_tgt(struct dfs_cache_tgt_list * tl,struct dfs_cache_tgt_iterator * it)55  dfs_cache_get_next_tgt(struct dfs_cache_tgt_list *tl,
56  		       struct dfs_cache_tgt_iterator *it)
57  {
58  	if (!tl || !tl->tl_numtgts || list_empty(&tl->tl_list) ||
59  	    !it || list_is_last(&it->it_list, &tl->tl_list))
60  		return NULL;
61  	return list_next_entry(it, it_list);
62  }
63  
64  static inline struct dfs_cache_tgt_iterator *
dfs_cache_get_tgt_iterator(struct dfs_cache_tgt_list * tl)65  dfs_cache_get_tgt_iterator(struct dfs_cache_tgt_list *tl)
66  {
67  	if (!tl)
68  		return NULL;
69  	return list_first_entry_or_null(&tl->tl_list,
70  					struct dfs_cache_tgt_iterator,
71  					it_list);
72  }
73  
dfs_cache_free_tgts(struct dfs_cache_tgt_list * tl)74  static inline void dfs_cache_free_tgts(struct dfs_cache_tgt_list *tl)
75  {
76  	struct dfs_cache_tgt_iterator *it, *nit;
77  
78  	if (!tl || !tl->tl_numtgts || list_empty(&tl->tl_list))
79  		return;
80  	list_for_each_entry_safe(it, nit, &tl->tl_list, it_list) {
81  		list_del(&it->it_list);
82  		kfree(it->it_name);
83  		kfree(it);
84  	}
85  	tl->tl_numtgts = 0;
86  }
87  
88  static inline const char *
dfs_cache_get_tgt_name(const struct dfs_cache_tgt_iterator * it)89  dfs_cache_get_tgt_name(const struct dfs_cache_tgt_iterator *it)
90  {
91  	return it ? it->it_name : NULL;
92  }
93  
94  static inline int
dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list * tl)95  dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list *tl)
96  {
97  	return tl ? tl->tl_numtgts : 0;
98  }
99  
dfs_cache_get_ttl(void)100  static inline int dfs_cache_get_ttl(void)
101  {
102  	return atomic_read(&dfs_cache_ttl);
103  }
104  
105  #endif /* _CIFS_DFS_CACHE_H */
106