xref: /linux/fs/smb/client/dfs_cache.h (revision fcc9f8cc812db02ab9c9fd41143c66d659dfc40c)
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,
41 		   const struct nls_table *cp, int remap, const char *path,
42 		   struct dfs_info3_param *ref,
43 		   struct dfs_cache_tgt_list *tgt_list);
44 int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
45 			 struct dfs_cache_tgt_list *tgt_list);
46 void dfs_cache_noreq_update_tgthint(const char *path,
47 				    const struct dfs_cache_tgt_iterator *it);
48 int dfs_cache_get_tgt_referral(const char *path,
49 			       const struct dfs_cache_tgt_iterator *it,
50 			       struct dfs_info3_param *ref);
51 int dfs_cache_get_tgt_share(char *path,
52 			    const struct dfs_cache_tgt_iterator *it,
53 			    char **share, char **prefix);
54 char *dfs_cache_canonical_path(const char *path, const struct nls_table *cp,
55 			       int remap);
56 int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb);
57 void dfs_cache_refresh(struct work_struct *work);
58 
59 static inline struct dfs_cache_tgt_iterator *
60 dfs_cache_get_next_tgt(struct dfs_cache_tgt_list *tl,
61 		       struct dfs_cache_tgt_iterator *it)
62 {
63 	if (!tl || !tl->tl_numtgts || list_empty(&tl->tl_list) ||
64 	    !it || list_is_last(&it->it_list, &tl->tl_list))
65 		return NULL;
66 	return list_next_entry(it, it_list);
67 }
68 
69 static inline struct dfs_cache_tgt_iterator *
70 dfs_cache_get_tgt_iterator(struct dfs_cache_tgt_list *tl)
71 {
72 	if (!tl)
73 		return NULL;
74 	return list_first_entry_or_null(&tl->tl_list,
75 					struct dfs_cache_tgt_iterator,
76 					it_list);
77 }
78 
79 static inline void dfs_cache_free_tgts(struct dfs_cache_tgt_list *tl)
80 {
81 	struct dfs_cache_tgt_iterator *it, *nit;
82 
83 	if (!tl || !tl->tl_numtgts || list_empty(&tl->tl_list))
84 		return;
85 	list_for_each_entry_safe(it, nit, &tl->tl_list, it_list) {
86 		list_del(&it->it_list);
87 		kfree(it->it_name);
88 		kfree(it);
89 	}
90 	tl->tl_numtgts = 0;
91 }
92 
93 static inline const char *
94 dfs_cache_get_tgt_name(const struct dfs_cache_tgt_iterator *it)
95 {
96 	return it ? it->it_name : NULL;
97 }
98 
99 static inline int
100 dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list *tl)
101 {
102 	return tl ? tl->tl_numtgts : 0;
103 }
104 
105 static inline int dfs_cache_get_ttl(void)
106 {
107 	return atomic_read(&dfs_cache_ttl);
108 }
109 
110 #endif /* _CIFS_DFS_CACHE_H */
111