1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Functions to handle the cached directory entries
4 *
5 * Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
6 */
7
8 #ifndef _CACHED_DIR_H
9 #define _CACHED_DIR_H
10
11
12 struct cached_dirent {
13 struct list_head entry;
14 char *name;
15 int namelen;
16 loff_t pos;
17 struct cifs_fattr fattr;
18 };
19
20 struct cached_dirents {
21 bool is_valid:1;
22 bool is_failed:1;
23 struct file *file; /*
24 * Used to associate the cache with a single
25 * open file instance.
26 */
27 struct mutex de_mutex;
28 loff_t pos; /* Expected ctx->pos */
29 struct list_head entries;
30 /* accounting for cached entries in this directory */
31 unsigned long entries_count;
32 unsigned long bytes_used;
33 };
34
35 struct cached_fid {
36 struct list_head entry;
37 struct cached_fids *cfids;
38 const char *path;
39 bool has_lease:1;
40 bool is_open:1;
41 bool on_list:1;
42 bool file_all_info_is_valid:1;
43 unsigned long time; /* jiffies of when lease was taken */
44 unsigned long last_access_time; /* jiffies of when last accessed */
45 struct kref refcount;
46 struct cifs_fid fid;
47 struct cifs_tcon *tcon;
48 struct dentry *dentry;
49 struct work_struct put_work;
50 struct work_struct close_work;
51 struct smb2_file_all_info file_all_info;
52 struct cached_dirents dirents;
53 };
54
55 /* default MAX_CACHED_FIDS is 16 */
56 struct cached_fids {
57 /* Must be held when:
58 * - accessing the cfids->entries list
59 * - accessing the cfids->dying list
60 */
61 spinlock_t cfid_list_lock;
62 int num_entries;
63 struct list_head entries;
64 struct list_head dying;
65 struct work_struct invalidation_work;
66 struct delayed_work laundromat_work;
67 /* aggregate accounting for all cached dirents under this tcon */
68 atomic_long_t total_dirents_entries;
69 atomic64_t total_dirents_bytes;
70 };
71
72 /* Module-wide directory cache accounting (defined in cifsfs.c) */
73 extern atomic64_t cifs_dircache_bytes_used; /* bytes across all mounts */
74
75 static inline bool
is_valid_cached_dir(struct cached_fid * cfid)76 is_valid_cached_dir(struct cached_fid *cfid)
77 {
78 return cfid->time && cfid->has_lease;
79 }
80
81 extern struct cached_fids *init_cached_dirs(void);
82 extern void free_cached_dirs(struct cached_fids *cfids);
83 extern int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
84 const char *path,
85 struct cifs_sb_info *cifs_sb,
86 bool lookup_only, struct cached_fid **cfid);
87 extern int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
88 struct dentry *dentry,
89 struct cached_fid **cfid);
90 extern void close_cached_dir(struct cached_fid *cfid);
91 extern void drop_cached_dir_by_name(const unsigned int xid,
92 struct cifs_tcon *tcon,
93 const char *name,
94 struct cifs_sb_info *cifs_sb);
95 extern void close_all_cached_dirs(struct cifs_sb_info *cifs_sb);
96 extern void invalidate_all_cached_dirs(struct cifs_tcon *tcon);
97 extern bool cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16]);
98
99 #endif /* _CACHED_DIR_H */
100