1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 * CIFS filesystem cache interface
4 *
5 * Copyright (c) 2010 Novell, Inc.
6 * Author(s): Suresh Jayaraman <sjayaraman@suse.de>
7 *
8 */
9 #include "fscache.h"
10 #include "cifsglob.h"
11 #include "cifs_debug.h"
12 #include "cifs_fs_sb.h"
13 #include "cifsproto.h"
14
15 /*
16 * Key for fscache inode. [!] Contents must match comparisons in cifs_find_inode().
17 */
18 struct cifs_fscache_inode_key {
19
20 __le64 uniqueid; /* server inode number */
21 __le64 createtime; /* creation time on server */
22 u8 type; /* S_IFMT file type */
23 } __packed;
24
25 static void cifs_fscache_fill_volume_coherency(
26 struct cifs_tcon *tcon,
27 struct cifs_fscache_volume_coherency_data *cd)
28 {
29 memset(cd, 0, sizeof(*cd));
30 cd->resource_id = cpu_to_le64(tcon->resource_id);
31 cd->vol_create_time = tcon->vol_create_time;
32 cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number);
33 }
34
35 int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
36 {
37 struct cifs_fscache_volume_coherency_data cd;
38 struct TCP_Server_Info *server = tcon->ses->server;
39 struct fscache_volume *vcookie;
40 const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr;
41 size_t slen, i;
42 char *sharename;
43 char *key;
44 int ret = -ENOMEM;
45
46 if (tcon->fscache_acquired)
47 return 0;
48
49 mutex_lock(&tcon->fscache_lock);
50 if (tcon->fscache_acquired) {
51 mutex_unlock(&tcon->fscache_lock);
52 return 0;
53 }
54 tcon->fscache_acquired = true;
55
56 tcon->fscache = NULL;
57 switch (sa->sa_family) {
58 case AF_INET:
59 case AF_INET6:
60 break;
61 default:
62 mutex_unlock(&tcon->fscache_lock);
63 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
64 return -EINVAL;
65 }
66
67 memset(&key, 0, sizeof(key));
68
69 sharename = extract_sharename(tcon->tree_name);
70 if (IS_ERR(sharename)) {
71 mutex_unlock(&tcon->fscache_lock);
72 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
73 return PTR_ERR(sharename);
74 }
75
76 slen = strlen(sharename);
77 for (i = 0; i < slen; i++)
78 if (sharename[i] == '/')
79 sharename[i] = ';';
80
81 key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename);
82 if (!key)
83 goto out;
84
85 cifs_fscache_fill_volume_coherency(tcon, &cd);
86 vcookie = fscache_acquire_volume(key,
87 NULL, /* preferred_cache */
88 &cd, sizeof(cd));
89 cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie);
90 if (IS_ERR(vcookie)) {
91 if (vcookie != ERR_PTR(-EBUSY)) {
92 ret = PTR_ERR(vcookie);
93 goto out_2;
94 }
95 pr_err("Cache volume key already in use (%s)\n", key);
96 vcookie = NULL;
97 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
98 netfs_trace_tcon_ref_see_fscache_collision);
99 } else {
100 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
101 netfs_trace_tcon_ref_see_fscache_okay);
102 }
103
104 tcon->fscache = vcookie;
105 ret = 0;
106 out_2:
107 kfree(key);
108 out:
109 kfree(sharename);
110 mutex_unlock(&tcon->fscache_lock);
111 return ret;
112 }
113
114 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
115 {
116 struct cifs_fscache_volume_coherency_data cd;
117
118 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
119
120 cifs_fscache_fill_volume_coherency(tcon, &cd);
121 fscache_relinquish_volume(tcon->fscache, &cd, false);
122 tcon->fscache = NULL;
123 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
124 netfs_trace_tcon_ref_see_fscache_relinq);
125 }
126
127 void cifs_fscache_get_inode_cookie(struct inode *inode)
128 {
129 struct cifs_fscache_inode_coherency_data cd;
130 struct cifs_fscache_inode_key key;
131 struct cifsInodeInfo *cifsi = CIFS_I(inode);
132 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
133 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
134
135 key.uniqueid = cpu_to_le64(cifsi->uniqueid);
136 key.createtime = cpu_to_le64(cifsi->createtime);
137 key.type = (inode->i_mode & S_IFMT) >> 12;
138 cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd);
139
140 cifsi->netfs.cache =
141 fscache_acquire_cookie(tcon->fscache, 0,
142 &key, sizeof(key),
143 &cd, sizeof(cd),
144 i_size_read(&cifsi->netfs.inode));
145 if (cifsi->netfs.cache)
146 mapping_set_release_always(inode->i_mapping);
147 }
148
149 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
150 {
151 if (update) {
152 struct cifs_fscache_inode_coherency_data cd;
153 loff_t i_size = i_size_read(inode);
154
155 cifs_fscache_fill_coherency(inode, &cd);
156 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size);
157 } else {
158 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL);
159 }
160 }
161
162 void cifs_fscache_release_inode_cookie(struct inode *inode)
163 {
164 struct cifsInodeInfo *cifsi = CIFS_I(inode);
165 struct fscache_cookie *cookie = cifs_inode_cookie(inode);
166
167 if (cookie) {
168 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie);
169 fscache_relinquish_cookie(cookie, false);
170 cifsi->netfs.cache = NULL;
171 }
172 }
173
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.