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
cifs_fscache_fill_volume_coherency(struct cifs_tcon * tcon,struct cifs_fscache_volume_coherency_data * cd)15 static void cifs_fscache_fill_volume_coherency(
16 struct cifs_tcon *tcon,
17 struct cifs_fscache_volume_coherency_data *cd)
18 {
19 memset(cd, 0, sizeof(*cd));
20 cd->resource_id = cpu_to_le64(tcon->resource_id);
21 cd->vol_create_time = tcon->vol_create_time;
22 cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number);
23 }
24
cifs_fscache_get_super_cookie(struct cifs_tcon * tcon)25 int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
26 {
27 struct cifs_fscache_volume_coherency_data cd;
28 struct TCP_Server_Info *server = tcon->ses->server;
29 struct fscache_volume *vcookie;
30 const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr;
31 size_t slen, i;
32 char *sharename;
33 char *key;
34 int ret = -ENOMEM;
35
36 tcon->fscache = NULL;
37 switch (sa->sa_family) {
38 case AF_INET:
39 case AF_INET6:
40 break;
41 default:
42 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
43 return -EINVAL;
44 }
45
46 memset(&key, 0, sizeof(key));
47
48 sharename = extract_sharename(tcon->tree_name);
49 if (IS_ERR(sharename)) {
50 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
51 return PTR_ERR(sharename);
52 }
53
54 slen = strlen(sharename);
55 for (i = 0; i < slen; i++)
56 if (sharename[i] == '/')
57 sharename[i] = ';';
58
59 key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename);
60 if (!key)
61 goto out;
62
63 cifs_fscache_fill_volume_coherency(tcon, &cd);
64 vcookie = fscache_acquire_volume(key,
65 NULL, /* preferred_cache */
66 &cd, sizeof(cd));
67 cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie);
68 if (IS_ERR(vcookie)) {
69 if (vcookie != ERR_PTR(-EBUSY)) {
70 ret = PTR_ERR(vcookie);
71 goto out_2;
72 }
73 pr_err("Cache volume key already in use (%s)\n", key);
74 vcookie = NULL;
75 }
76
77 tcon->fscache = vcookie;
78 ret = 0;
79 out_2:
80 kfree(key);
81 out:
82 kfree(sharename);
83 return ret;
84 }
85
cifs_fscache_release_super_cookie(struct cifs_tcon * tcon)86 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
87 {
88 struct cifs_fscache_volume_coherency_data cd;
89
90 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
91
92 cifs_fscache_fill_volume_coherency(tcon, &cd);
93 fscache_relinquish_volume(tcon->fscache, &cd, false);
94 tcon->fscache = NULL;
95 }
96
cifs_fscache_get_inode_cookie(struct inode * inode)97 void cifs_fscache_get_inode_cookie(struct inode *inode)
98 {
99 struct cifs_fscache_inode_coherency_data cd;
100 struct cifsInodeInfo *cifsi = CIFS_I(inode);
101 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
102 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
103
104 cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd);
105
106 cifsi->netfs.cache =
107 fscache_acquire_cookie(tcon->fscache, 0,
108 &cifsi->uniqueid, sizeof(cifsi->uniqueid),
109 &cd, sizeof(cd),
110 i_size_read(&cifsi->netfs.inode));
111 if (cifsi->netfs.cache)
112 mapping_set_release_always(inode->i_mapping);
113 }
114
cifs_fscache_unuse_inode_cookie(struct inode * inode,bool update)115 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
116 {
117 if (update) {
118 struct cifs_fscache_inode_coherency_data cd;
119 loff_t i_size = i_size_read(inode);
120
121 cifs_fscache_fill_coherency(inode, &cd);
122 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size);
123 } else {
124 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL);
125 }
126 }
127
cifs_fscache_release_inode_cookie(struct inode * inode)128 void cifs_fscache_release_inode_cookie(struct inode *inode)
129 {
130 struct cifsInodeInfo *cifsi = CIFS_I(inode);
131 struct fscache_cookie *cookie = cifs_inode_cookie(inode);
132
133 if (cookie) {
134 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie);
135 fscache_relinquish_cookie(cookie, false);
136 cifsi->netfs.cache = NULL;
137 }
138 }
139
140 /*
141 * Fallback page reading interface.
142 */
fscache_fallback_read_page(struct inode * inode,struct page * page)143 static int fscache_fallback_read_page(struct inode *inode, struct page *page)
144 {
145 struct netfs_cache_resources cres;
146 struct fscache_cookie *cookie = cifs_inode_cookie(inode);
147 struct iov_iter iter;
148 struct bio_vec bvec;
149 int ret;
150
151 memset(&cres, 0, sizeof(cres));
152 bvec_set_page(&bvec, page, PAGE_SIZE, 0);
153 iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE);
154
155 ret = fscache_begin_read_operation(&cres, cookie);
156 if (ret < 0)
157 return ret;
158
159 ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL,
160 NULL, NULL);
161 fscache_end_operation(&cres);
162 return ret;
163 }
164
165 /*
166 * Fallback page writing interface.
167 */
fscache_fallback_write_pages(struct inode * inode,loff_t start,size_t len,bool no_space_allocated_yet)168 static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len,
169 bool no_space_allocated_yet)
170 {
171 struct netfs_cache_resources cres;
172 struct fscache_cookie *cookie = cifs_inode_cookie(inode);
173 struct iov_iter iter;
174 int ret;
175
176 memset(&cres, 0, sizeof(cres));
177 iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len);
178
179 ret = fscache_begin_write_operation(&cres, cookie);
180 if (ret < 0)
181 return ret;
182
183 ret = cres.ops->prepare_write(&cres, &start, &len, len, i_size_read(inode),
184 no_space_allocated_yet);
185 if (ret == 0)
186 ret = fscache_write(&cres, start, &iter, NULL, NULL);
187 fscache_end_operation(&cres);
188 return ret;
189 }
190
191 /*
192 * Retrieve a page from FS-Cache
193 */
__cifs_readpage_from_fscache(struct inode * inode,struct page * page)194 int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
195 {
196 int ret;
197
198 cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
199 __func__, cifs_inode_cookie(inode), page, inode);
200
201 ret = fscache_fallback_read_page(inode, page);
202 if (ret < 0)
203 return ret;
204
205 /* Read completed synchronously */
206 SetPageUptodate(page);
207 return 0;
208 }
209
__cifs_readahead_to_fscache(struct inode * inode,loff_t pos,size_t len)210 void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len)
211 {
212 cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n",
213 __func__, cifs_inode_cookie(inode), pos, len, inode);
214
215 fscache_fallback_write_pages(inode, pos, len, true);
216 }
217
218 /*
219 * Query the cache occupancy.
220 */
__cifs_fscache_query_occupancy(struct inode * inode,pgoff_t first,unsigned int nr_pages,pgoff_t * _data_first,unsigned int * _data_nr_pages)221 int __cifs_fscache_query_occupancy(struct inode *inode,
222 pgoff_t first, unsigned int nr_pages,
223 pgoff_t *_data_first,
224 unsigned int *_data_nr_pages)
225 {
226 struct netfs_cache_resources cres;
227 struct fscache_cookie *cookie = cifs_inode_cookie(inode);
228 loff_t start, data_start;
229 size_t len, data_len;
230 int ret;
231
232 ret = fscache_begin_read_operation(&cres, cookie);
233 if (ret < 0)
234 return ret;
235
236 start = first * PAGE_SIZE;
237 len = nr_pages * PAGE_SIZE;
238 ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE,
239 &data_start, &data_len);
240 if (ret == 0) {
241 *_data_first = data_start / PAGE_SIZE;
242 *_data_nr_pages = len / PAGE_SIZE;
243 }
244
245 fscache_end_operation(&cres);
246 return ret;
247 }
248