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@infradead.org>
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/fs.h>
20#include <linux/pagemap.h>
21#include <linux/sched.h>
22#include <linux/mount.h>
23#include <linux/namei.h>
24#include "internal.h"
25
26struct afs_iget_data {
27	struct afs_fid		fid;
28	struct afs_volume	*volume;	/* volume on which resides */
29};
30
31/*
32 * map the AFS file status to the inode member variables
33 */
34static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
35{
36	struct inode *inode = AFS_VNODE_TO_I(vnode);
37
38	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
39	       vnode->status.type,
40	       vnode->status.nlink,
41	       (unsigned long long) vnode->status.size,
42	       vnode->status.data_version,
43	       vnode->status.mode);
44
45	switch (vnode->status.type) {
46	case AFS_FTYPE_FILE:
47		inode->i_mode	= S_IFREG | vnode->status.mode;
48		inode->i_op	= &afs_file_inode_operations;
49		inode->i_fop	= &afs_file_operations;
50		break;
51	case AFS_FTYPE_DIR:
52		inode->i_mode	= S_IFDIR | vnode->status.mode;
53		inode->i_op	= &afs_dir_inode_operations;
54		inode->i_fop	= &afs_dir_file_operations;
55		break;
56	case AFS_FTYPE_SYMLINK:
57		inode->i_mode	= S_IFLNK | vnode->status.mode;
58		inode->i_op	= &page_symlink_inode_operations;
59		break;
60	default:
61		printk("kAFS: AFS vnode with undefined type\n");
62		return -EBADMSG;
63	}
64
65#ifdef CONFIG_AFS_FSCACHE
66	if (vnode->status.size != inode->i_size)
67		fscache_attr_changed(vnode->cache);
68#endif
69
70	set_nlink(inode, vnode->status.nlink);
71	inode->i_uid		= vnode->status.owner;
72	inode->i_gid		= GLOBAL_ROOT_GID;
73	inode->i_size		= vnode->status.size;
74	inode->i_ctime.tv_sec	= vnode->status.mtime_server;
75	inode->i_ctime.tv_nsec	= 0;
76	inode->i_atime		= inode->i_mtime = inode->i_ctime;
77	inode->i_blocks		= 0;
78	inode->i_generation	= vnode->fid.unique;
79	inode->i_version	= vnode->status.data_version;
80	inode->i_mapping->a_ops	= &afs_fs_aops;
81
82	/* check to see whether a symbolic link is really a mountpoint */
83	if (vnode->status.type == AFS_FTYPE_SYMLINK) {
84		afs_mntpt_check_symlink(vnode, key);
85
86		if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) {
87			inode->i_mode	= S_IFDIR | vnode->status.mode;
88			inode->i_op	= &afs_mntpt_inode_operations;
89			inode->i_fop	= &afs_mntpt_file_operations;
90		}
91	}
92
93	return 0;
94}
95
96/*
97 * iget5() comparator
98 */
99static int afs_iget5_test(struct inode *inode, void *opaque)
100{
101	struct afs_iget_data *data = opaque;
102
103	return inode->i_ino == data->fid.vnode &&
104		inode->i_generation == data->fid.unique;
105}
106
107/*
108 * iget5() comparator for inode created by autocell operations
109 *
110 * These pseudo inodes don't match anything.
111 */
112static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
113{
114	return 0;
115}
116
117/*
118 * iget5() inode initialiser
119 */
120static int afs_iget5_set(struct inode *inode, void *opaque)
121{
122	struct afs_iget_data *data = opaque;
123	struct afs_vnode *vnode = AFS_FS_I(inode);
124
125	inode->i_ino = data->fid.vnode;
126	inode->i_generation = data->fid.unique;
127	vnode->fid = data->fid;
128	vnode->volume = data->volume;
129
130	return 0;
131}
132
133/*
134 * inode retrieval for autocell
135 */
136struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
137				int namesz, struct key *key)
138{
139	struct afs_iget_data data;
140	struct afs_super_info *as;
141	struct afs_vnode *vnode;
142	struct super_block *sb;
143	struct inode *inode;
144	static atomic_t afs_autocell_ino;
145
146	_enter("{%x:%u},%*.*s,",
147	       AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
148	       namesz, namesz, dev_name ?: "");
149
150	sb = dir->i_sb;
151	as = sb->s_fs_info;
152	data.volume = as->volume;
153	data.fid.vid = as->volume->vid;
154	data.fid.unique = 0;
155	data.fid.vnode = 0;
156
157	inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
158			     afs_iget5_autocell_test, afs_iget5_set,
159			     &data);
160	if (!inode) {
161		_leave(" = -ENOMEM");
162		return ERR_PTR(-ENOMEM);
163	}
164
165	_debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }",
166	       inode, inode->i_ino, data.fid.vid, data.fid.vnode,
167	       data.fid.unique);
168
169	vnode = AFS_FS_I(inode);
170
171	/* there shouldn't be an existing inode */
172	BUG_ON(!(inode->i_state & I_NEW));
173
174	inode->i_size		= 0;
175	inode->i_mode		= S_IFDIR | S_IRUGO | S_IXUGO;
176	inode->i_op		= &afs_autocell_inode_operations;
177	set_nlink(inode, 2);
178	inode->i_uid		= GLOBAL_ROOT_UID;
179	inode->i_gid		= GLOBAL_ROOT_GID;
180	inode->i_ctime.tv_sec	= get_seconds();
181	inode->i_ctime.tv_nsec	= 0;
182	inode->i_atime		= inode->i_mtime = inode->i_ctime;
183	inode->i_blocks		= 0;
184	inode->i_version	= 0;
185	inode->i_generation	= 0;
186
187	set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
188	set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
189	inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
190	unlock_new_inode(inode);
191	_leave(" = %p", inode);
192	return inode;
193}
194
195/*
196 * inode retrieval
197 */
198struct inode *afs_iget(struct super_block *sb, struct key *key,
199		       struct afs_fid *fid, struct afs_file_status *status,
200		       struct afs_callback *cb)
201{
202	struct afs_iget_data data = { .fid = *fid };
203	struct afs_super_info *as;
204	struct afs_vnode *vnode;
205	struct inode *inode;
206	int ret;
207
208	_enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique);
209
210	as = sb->s_fs_info;
211	data.volume = as->volume;
212
213	inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
214			     &data);
215	if (!inode) {
216		_leave(" = -ENOMEM");
217		return ERR_PTR(-ENOMEM);
218	}
219
220	_debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
221	       inode, fid->vid, fid->vnode, fid->unique);
222
223	vnode = AFS_FS_I(inode);
224
225	/* deal with an existing inode */
226	if (!(inode->i_state & I_NEW)) {
227		_leave(" = %p", inode);
228		return inode;
229	}
230
231	if (!status) {
232		/* it's a remotely extant inode */
233		set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
234		ret = afs_vnode_fetch_status(vnode, NULL, key);
235		if (ret < 0)
236			goto bad_inode;
237	} else {
238		/* it's an inode we just created */
239		memcpy(&vnode->status, status, sizeof(vnode->status));
240
241		if (!cb) {
242			/* it's a symlink we just created (the fileserver
243			 * didn't give us a callback) */
244			vnode->cb_version = 0;
245			vnode->cb_expiry = 0;
246			vnode->cb_type = 0;
247			vnode->cb_expires = get_seconds();
248		} else {
249			vnode->cb_version = cb->version;
250			vnode->cb_expiry = cb->expiry;
251			vnode->cb_type = cb->type;
252			vnode->cb_expires = vnode->cb_expiry + get_seconds();
253		}
254	}
255
256	/* set up caching before mapping the status, as map-status reads the
257	 * first page of symlinks to see if they're really mountpoints */
258	inode->i_size = vnode->status.size;
259#ifdef CONFIG_AFS_FSCACHE
260	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
261					      &afs_vnode_cache_index_def,
262					      vnode, true);
263#endif
264
265	ret = afs_inode_map_status(vnode, key);
266	if (ret < 0)
267		goto bad_inode;
268
269	/* success */
270	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
271	inode->i_flags |= S_NOATIME;
272	unlock_new_inode(inode);
273	_leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
274	return inode;
275
276	/* failure */
277bad_inode:
278#ifdef CONFIG_AFS_FSCACHE
279	fscache_relinquish_cookie(vnode->cache, 0);
280	vnode->cache = NULL;
281#endif
282	iget_failed(inode);
283	_leave(" = %d [bad]", ret);
284	return ERR_PTR(ret);
285}
286
287/*
288 * mark the data attached to an inode as obsolete due to a write on the server
289 * - might also want to ditch all the outstanding writes and dirty pages
290 */
291void afs_zap_data(struct afs_vnode *vnode)
292{
293	_enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
294
295	/* nuke all the non-dirty pages that aren't locked, mapped or being
296	 * written back in a regular file and completely discard the pages in a
297	 * directory or symlink */
298	if (S_ISREG(vnode->vfs_inode.i_mode))
299		invalidate_remote_inode(&vnode->vfs_inode);
300	else
301		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
302}
303
304/*
305 * validate a vnode/inode
306 * - there are several things we need to check
307 *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
308 *     symlink)
309 *   - parent dir metadata changed (security changes)
310 *   - dentry data changed (write, truncate)
311 *   - dentry metadata changed (security changes)
312 */
313int afs_validate(struct afs_vnode *vnode, struct key *key)
314{
315	int ret;
316
317	_enter("{v={%x:%u} fl=%lx},%x",
318	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
319	       key_serial(key));
320
321	if (vnode->cb_promised &&
322	    !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
323	    !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
324	    !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
325		if (vnode->cb_expires < get_seconds() + 10) {
326			_debug("callback expired");
327			set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
328		} else {
329			goto valid;
330		}
331	}
332
333	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
334		goto valid;
335
336	mutex_lock(&vnode->validate_lock);
337
338	/* if the promise has expired, we need to check the server again to get
339	 * a new promise - note that if the (parent) directory's metadata was
340	 * changed then the security may be different and we may no longer have
341	 * access */
342	if (!vnode->cb_promised ||
343	    test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
344		_debug("not promised");
345		ret = afs_vnode_fetch_status(vnode, NULL, key);
346		if (ret < 0)
347			goto error_unlock;
348		_debug("new promise [fl=%lx]", vnode->flags);
349	}
350
351	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
352		_debug("file already deleted");
353		ret = -ESTALE;
354		goto error_unlock;
355	}
356
357	/* if the vnode's data version number changed then its contents are
358	 * different */
359	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
360		afs_zap_data(vnode);
361
362	clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
363	mutex_unlock(&vnode->validate_lock);
364valid:
365	_leave(" = 0");
366	return 0;
367
368error_unlock:
369	mutex_unlock(&vnode->validate_lock);
370	_leave(" = %d", ret);
371	return ret;
372}
373
374/*
375 * read the attributes of an inode
376 */
377int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
378		      struct kstat *stat)
379{
380	struct inode *inode;
381
382	inode = d_inode(dentry);
383
384	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
385
386	generic_fillattr(inode, stat);
387	return 0;
388}
389
390/*
391 * discard an AFS inode
392 */
393int afs_drop_inode(struct inode *inode)
394{
395	_enter("");
396
397	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
398		return generic_delete_inode(inode);
399	else
400		return generic_drop_inode(inode);
401}
402
403/*
404 * clear an AFS inode
405 */
406void afs_evict_inode(struct inode *inode)
407{
408	struct afs_permits *permits;
409	struct afs_vnode *vnode;
410
411	vnode = AFS_FS_I(inode);
412
413	_enter("{%x:%u.%d} v=%u x=%u t=%u }",
414	       vnode->fid.vid,
415	       vnode->fid.vnode,
416	       vnode->fid.unique,
417	       vnode->cb_version,
418	       vnode->cb_expiry,
419	       vnode->cb_type);
420
421	_debug("CLEAR INODE %p", inode);
422
423	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
424
425	truncate_inode_pages_final(&inode->i_data);
426	clear_inode(inode);
427
428	afs_give_up_callback(vnode);
429
430	if (vnode->server) {
431		spin_lock(&vnode->server->fs_lock);
432		rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
433		spin_unlock(&vnode->server->fs_lock);
434		afs_put_server(vnode->server);
435		vnode->server = NULL;
436	}
437
438	ASSERT(list_empty(&vnode->writebacks));
439	ASSERT(!vnode->cb_promised);
440
441#ifdef CONFIG_AFS_FSCACHE
442	fscache_relinquish_cookie(vnode->cache, 0);
443	vnode->cache = NULL;
444#endif
445
446	mutex_lock(&vnode->permits_lock);
447	permits = vnode->permits;
448	rcu_assign_pointer(vnode->permits, NULL);
449	mutex_unlock(&vnode->permits_lock);
450	if (permits)
451		call_rcu(&permits->rcu, afs_zap_permits);
452
453	_leave("");
454}
455
456/*
457 * set the attributes of an inode
458 */
459int afs_setattr(struct dentry *dentry, struct iattr *attr)
460{
461	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
462	struct key *key;
463	int ret;
464
465	_enter("{%x:%u},{n=%pd},%x",
466	       vnode->fid.vid, vnode->fid.vnode, dentry,
467	       attr->ia_valid);
468
469	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
470				ATTR_MTIME))) {
471		_leave(" = 0 [unsupported]");
472		return 0;
473	}
474
475	/* flush any dirty data outstanding on a regular file */
476	if (S_ISREG(vnode->vfs_inode.i_mode)) {
477		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
478		afs_writeback_all(vnode);
479	}
480
481	if (attr->ia_valid & ATTR_FILE) {
482		key = attr->ia_file->private_data;
483	} else {
484		key = afs_request_key(vnode->volume->cell);
485		if (IS_ERR(key)) {
486			ret = PTR_ERR(key);
487			goto error;
488		}
489	}
490
491	ret = afs_vnode_setattr(vnode, key, attr);
492	if (!(attr->ia_valid & ATTR_FILE))
493		key_put(key);
494
495error:
496	_leave(" = %d", ret);
497	return ret;
498}
499