1 /*
2 * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
3 *
4 * This software may be freely redistributed under the terms of the
5 * GNU General Public License.
6 *
7 * You should have received a copy of the GNU General Public License
8 * along with this program; if not, write to the Free Software
9 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
10 *
11 * Authors: David Woodhouse <dwmw2@cambridge.redhat.com>
12 * David Howells <dhowells@redhat.com>
13 *
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/fs.h>
21 #include <linux/pagemap.h>
22 #include <linux/sched.h>
23 #include "internal.h"
24
25 struct afs_iget_data {
26 struct afs_fid fid;
27 struct afs_volume *volume; /* volume on which resides */
28 };
29
30 /*
31 * map the AFS file status to the inode member variables
32 */
33 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
34 {
35 struct inode *inode = AFS_VNODE_TO_I(vnode);
36
37 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
38 vnode->status.type,
39 vnode->status.nlink,
40 (unsigned long long) vnode->status.size,
41 vnode->status.data_version,
42 vnode->status.mode);
43
44 switch (vnode->status.type) {
45 case AFS_FTYPE_FILE:
46 inode->i_mode = S_IFREG | vnode->status.mode;
47 inode->i_op = &afs_file_inode_operations;
48 inode->i_fop = &afs_file_operations;
49 break;
50 case AFS_FTYPE_DIR:
51 inode->i_mode = S_IFDIR | vnode->status.mode;
52 inode->i_op = &afs_dir_inode_operations;
53 inode->i_fop = &afs_dir_file_operations;
54 break;
55 case AFS_FTYPE_SYMLINK:
56 inode->i_mode = S_IFLNK | vnode->status.mode;
57 inode->i_op = &page_symlink_inode_operations;
58 break;
59 default:
60 printk("kAFS: AFS vnode with undefined type\n");
61 return -EBADMSG;
62 }
63
64 inode->i_nlink = vnode->status.nlink;
65 inode->i_uid = vnode->status.owner;
66 inode->i_gid = 0;
67 inode->i_size = vnode->status.size;
68 inode->i_ctime.tv_sec = vnode->status.mtime_server;
69 inode->i_ctime.tv_nsec = 0;
70 inode->i_atime = inode->i_mtime = inode->i_ctime;
71 inode->i_blocks = 0;
72 inode->i_version = vnode->fid.unique;
73 inode->i_mapping->a_ops = &afs_fs_aops;
74
75 /* check to see whether a symbolic link is really a mountpoint */
76 if (vnode->status.type == AFS_FTYPE_SYMLINK) {
77 afs_mntpt_check_symlink(vnode, key);
78
79 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) {
80 inode->i_mode = S_IFDIR | vnode->status.mode;
81 inode->i_op = &afs_mntpt_inode_operations;
82 inode->i_fop = &afs_mntpt_file_operations;
83 }
84 }
85
86 return 0;
87 }
88
89 /*
90 * iget5() comparator
91 */
92 static int afs_iget5_test(struct inode *inode, void *opaque)
93 {
94 struct afs_iget_data *data = opaque;
95
96 return inode->i_ino == data->fid.vnode &&
97 inode->i_version == data->fid.unique;
98 }
99
100 /*
101 * iget5() inode initialiser
102 */
103 static int afs_iget5_set(struct inode *inode, void *opaque)
104 {
105 struct afs_iget_data *data = opaque;
106 struct afs_vnode *vnode = AFS_FS_I(inode);
107
108 inode->i_ino = data->fid.vnode;
109 inode->i_version = data->fid.unique;
110 vnode->fid = data->fid;
111 vnode->volume = data->volume;
112
113 return 0;
114 }
115
116 /*
117 * inode retrieval
118 */
119 struct inode *afs_iget(struct super_block *sb, struct key *key,
120 struct afs_fid *fid, struct afs_file_status *status,
121 struct afs_callback *cb)
122 {
123 struct afs_iget_data data = { .fid = *fid };
124 struct afs_super_info *as;
125 struct afs_vnode *vnode;
126 struct inode *inode;
127 int ret;
128
129 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique);
130
131 as = sb->s_fs_info;
132 data.volume = as->volume;
133
134 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
135 &data);
136 if (!inode) {
137 _leave(" = -ENOMEM");
138 return ERR_PTR(-ENOMEM);
139 }
140
141 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
142 inode, fid->vid, fid->vnode, fid->unique);
143
144 vnode = AFS_FS_I(inode);
145
146 /* deal with an existing inode */
147 if (!(inode->i_state & I_NEW)) {
148 _leave(" = %p", inode);
149 return inode;
150 }
151
152 #ifdef AFS_CACHING_SUPPORT
153 /* set up caching before reading the status, as fetch-status reads the
154 * first page of symlinks to see if they're really mntpts */
155 cachefs_acquire_cookie(vnode->volume->cache,
156 NULL,
157 vnode,
158 &vnode->cache);
159 #endif
160
161 if (!status) {
162 /* it's a remotely extant inode */
163 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
164 ret = afs_vnode_fetch_status(vnode, NULL, key);
165 if (ret < 0)
166 goto bad_inode;
167 } else {
168 /* it's an inode we just created */
169 memcpy(&vnode->status, status, sizeof(vnode->status));
170
171 if (!cb) {
172 /* it's a symlink we just created (the fileserver
173 * didn't give us a callback) */
174 vnode->cb_version = 0;
175 vnode->cb_expiry = 0;
176 vnode->cb_type = 0;
177 vnode->cb_expires = get_seconds();
178 } else {
179 vnode->cb_version = cb->version;
180 vnode->cb_expiry = cb->expiry;
181 vnode->cb_type = cb->type;
182 vnode->cb_expires = vnode->cb_expiry + get_seconds();
183 }
184 }
185
186 ret = afs_inode_map_status(vnode, key);
187 if (ret < 0)
188 goto bad_inode;
189
190 /* success */
191 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
192 inode->i_flags |= S_NOATIME;
193 unlock_new_inode(inode);
194 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
195 return inode;
196
197 /* failure */
198 bad_inode:
199 iget_failed(inode);
200 _leave(" = %d [bad]", ret);
201 return ERR_PTR(ret);
202 }
203
204 /*
205 * mark the data attached to an inode as obsolete due to a write on the server
206 * - might also want to ditch all the outstanding writes and dirty pages
207 */
208 void afs_zap_data(struct afs_vnode *vnode)
209 {
210 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
211
212 /* nuke all the non-dirty pages that aren't locked, mapped or being
213 * written back in a regular file and completely discard the pages in a
214 * directory or symlink */
215 if (S_ISREG(vnode->vfs_inode.i_mode))
216 invalidate_remote_inode(&vnode->vfs_inode);
217 else
218 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
219 }
220
221 /*
222 * validate a vnode/inode
223 * - there are several things we need to check
224 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
225 * symlink)
226 * - parent dir metadata changed (security changes)
227 * - dentry data changed (write, truncate)
228 * - dentry metadata changed (security changes)
229 */
230 int afs_validate(struct afs_vnode *vnode, struct key *key)
231 {
232 int ret;
233
234 _enter("{v={%x:%u} fl=%lx},%x",
235 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
236 key_serial(key));
237
238 if (vnode->cb_promised &&
239 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
240 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
241 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
242 if (vnode->cb_expires < get_seconds() + 10) {
243 _debug("callback expired");
244 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
245 } else {
246 goto valid;
247 }
248 }
249
250 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
251 goto valid;
252
253 mutex_lock(&vnode->validate_lock);
254
255 /* if the promise has expired, we need to check the server again to get
256 * a new promise - note that if the (parent) directory's metadata was
257 * changed then the security may be different and we may no longer have
258 * access */
259 if (!vnode->cb_promised ||
260 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
261 _debug("not promised");
262 ret = afs_vnode_fetch_status(vnode, NULL, key);
263 if (ret < 0)
264 goto error_unlock;
265 _debug("new promise [fl=%lx]", vnode->flags);
266 }
267
268 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
269 _debug("file already deleted");
270 ret = -ESTALE;
271 goto error_unlock;
272 }
273
274 /* if the vnode's data version number changed then its contents are
275 * different */
276 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
277 afs_zap_data(vnode);
278
279 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
280 mutex_unlock(&vnode->validate_lock);
281 valid:
282 _leave(" = 0");
283 return 0;
284
285 error_unlock:
286 mutex_unlock(&vnode->validate_lock);
287 _leave(" = %d", ret);
288 return ret;
289 }
290
291 /*
292 * read the attributes of an inode
293 */
294 int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
295 struct kstat *stat)
296 {
297 struct inode *inode;
298
299 inode = dentry->d_inode;
300
301 _enter("{ ino=%lu v=%llu }", inode->i_ino,
302 (unsigned long long)inode->i_version);
303
304 generic_fillattr(inode, stat);
305 return 0;
306 }
307
308 /*
309 * clear an AFS inode
310 */
311 void afs_clear_inode(struct inode *inode)
312 {
313 struct afs_permits *permits;
314 struct afs_vnode *vnode;
315
316 vnode = AFS_FS_I(inode);
317
318 _enter("{%x:%u.%d} v=%u x=%u t=%u }",
319 vnode->fid.vid,
320 vnode->fid.vnode,
321 vnode->fid.unique,
322 vnode->cb_version,
323 vnode->cb_expiry,
324 vnode->cb_type);
325
326 _debug("CLEAR INODE %p", inode);
327
328 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
329
330 afs_give_up_callback(vnode);
331
332 if (vnode->server) {
333 spin_lock(&vnode->server->fs_lock);
334 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
335 spin_unlock(&vnode->server->fs_lock);
336 afs_put_server(vnode->server);
337 vnode->server = NULL;
338 }
339
340 ASSERT(list_empty(&vnode->writebacks));
341 ASSERT(!vnode->cb_promised);
342
343 #ifdef AFS_CACHING_SUPPORT
344 cachefs_relinquish_cookie(vnode->cache, 0);
345 vnode->cache = NULL;
346 #endif
347
348 mutex_lock(&vnode->permits_lock);
349 permits = vnode->permits;
350 rcu_assign_pointer(vnode->permits, NULL);
351 mutex_unlock(&vnode->permits_lock);
352 if (permits)
353 call_rcu(&permits->rcu, afs_zap_permits);
354
355 _leave("");
356 }
357
358 /*
359 * set the attributes of an inode
360 */
361 int afs_setattr(struct dentry *dentry, struct iattr *attr)
362 {
363 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
364 struct key *key;
365 int ret;
366
367 _enter("{%x:%u},{n=%s},%x",
368 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
369 attr->ia_valid);
370
371 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
372 ATTR_MTIME))) {
373 _leave(" = 0 [unsupported]");
374 return 0;
375 }
376
377 /* flush any dirty data outstanding on a regular file */
378 if (S_ISREG(vnode->vfs_inode.i_mode)) {
379 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
380 afs_writeback_all(vnode);
381 }
382
383 if (attr->ia_valid & ATTR_FILE) {
384 key = attr->ia_file->private_data;
385 } else {
386 key = afs_request_key(vnode->volume->cell);
387 if (IS_ERR(key)) {
388 ret = PTR_ERR(key);
389 goto error;
390 }
391 }
392
393 ret = afs_vnode_setattr(vnode, key, attr);
394 if (!(attr->ia_valid & ATTR_FILE))
395 key_put(key);
396
397 error:
398 _leave(" = %d", ret);
399 return ret;
400 }
401
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