summaryrefslogtreecommitdiffstats
path: root/fs/nfsd/nfs4recover.c
blob: eb01fffdc2f1a65c54768f47175e04566b8db3b2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
/*
*  Copyright (c) 2004 The Regents of the University of Michigan.
*  All rights reserved.
*
*  Andy Adamson <andros@citi.umich.edu>
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*  2. Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in the
*     documentation and/or other materials provided with the distribution.
*  3. Neither the name of the University nor the names of its
*     contributors may be used to endorse or promote products derived
*     from this software without specific prior written permission.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/

#include <linux/file.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/crypto.h>
#include <linux/sched.h>

#include "nfsd.h"
#include "state.h"
#include "vfs.h"

#define NFSDDBG_FACILITY                NFSDDBG_PROC

/* Globals */
static struct file *rec_file;
static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";

static int
nfs4_save_creds(const struct cred **original_creds)
{
	struct cred *new;

	new = prepare_creds();
	if (!new)
		return -ENOMEM;

	new->fsuid = 0;
	new->fsgid = 0;
	*original_creds = override_creds(new);
	put_cred(new);
	return 0;
}

static void
nfs4_reset_creds(const struct cred *original)
{
	revert_creds(original);
}

static void
md5_to_hex(char *out, char *md5)
{
	int i;

	for (i=0; i<16; i++) {
		unsigned char c = md5[i];

		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
	}
	*out = '\0';
}

__be32
nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
{
	struct xdr_netobj cksum;
	struct hash_desc desc;
	struct scatterlist sg;
	__be32 status = nfserr_jukebox;

	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
			clname->len, clname->data);
	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
	desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(desc.tfm))
		goto out_no_tfm;
	cksum.len = crypto_hash_digestsize(desc.tfm);
	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
	if (cksum.data == NULL)
 		goto out;

	sg_init_one(&sg, clname->data, clname->len);

	if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
		goto out;

	md5_to_hex(dname, cksum.data);

	status = nfs_ok;
out:
	kfree(cksum.data);
	crypto_free_hash(desc.tfm);
out_no_tfm:
	return status;
}

int
nfsd4_create_clid_dir(struct nfs4_client *clp)
{
	const struct cred *original_cred;
	char *dname = clp->cl_recdir;
	struct dentry *dir, *dentry;
	int status;

	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);

	if (clp->cl_firststate)
		return 0;
	clp->cl_firststate = 1;
	if (!rec_file)
		return -ENOENT;
	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		return status;

	dir = rec_file->f_path.dentry;
	/* lock the parent */
	mutex_lock(&dir->d_inode->i_mutex);

	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
	if (IS_ERR(dentry)) {
		status = PTR_ERR(dentry);
		goto out_unlock;
	}
	if (dentry->d_inode)
		/*
		 * In the 4.1 case, where we're called from
		 * reclaim_complete(), records from the previous reboot
		 * may still be left, so this is OK.
		 *
		 * In the 4.0 case, we should never get here; but we may
		 * as well be forgiving and just succeed silently.
		 */
		goto out_put;
	status = mnt_want_write(rec_file->f_path.mnt);
	if (status)
		goto out_put;
	status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
	mnt_drop_write(rec_file->f_path.mnt);
out_put:
	dput(dentry);
out_unlock:
	mutex_unlock(&dir->d_inode->i_mutex);
	if (status == 0)
		vfs_fsync(rec_file, 0);
	else
		printk(KERN_ERR "NFSD: failed to write recovery record"
				" (err %d); please check that %s exists"
				" and is writeable", status,
				user_recovery_dirname);
	nfs4_reset_creds(original_cred);
	return status;
}

typedef int (recdir_func)(struct dentry *, struct dentry *);

struct name_list {
	char name[HEXDIR_LEN];
	struct list_head list;
};

static int
nfsd4_build_namelist(void *arg, const char *name, int namlen,
		loff_t offset, u64 ino, unsigned int d_type)
{
	struct list_head *names = arg;
	struct name_list *entry;

	if (namlen != HEXDIR_LEN - 1)
		return 0;
	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
	if (entry == NULL)
		return -ENOMEM;
	memcpy(entry->name, name, HEXDIR_LEN - 1);
	entry->name[HEXDIR_LEN - 1] = '\0';
	list_add(&entry->list, names);
	return 0;
}

static int
nfsd4_list_rec_dir(recdir_func *f)
{
	const struct cred *original_cred;
	struct dentry *dir = rec_file->f_path.dentry;
	LIST_HEAD(names);
	int status;

	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		return status;

	status = vfs_llseek(rec_file, 0, SEEK_SET);
	if (status < 0) {
		nfs4_reset_creds(original_cred);
		return status;
	}

	status = vfs_readdir(rec_file, nfsd4_build_namelist, &names);
	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
	while (!list_empty(&names)) {
		struct name_list *entry;
		entry = list_entry(names.next, struct name_list, list);
		if (!status) {
			struct dentry *dentry;
			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
			if (IS_ERR(dentry)) {
				status = PTR_ERR(dentry);
				break;
			}
			status = f(dir, dentry);
			dput(dentry);
		}
		list_del(&entry->list);
		kfree(entry);
	}
	mutex_unlock(&dir->d_inode->i_mutex);
	nfs4_reset_creds(original_cred);
	return status;
}

static int
nfsd4_unlink_clid_dir(char *name, int namlen)
{
	struct dentry *dir, *dentry;
	int status;

	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);

	dir = rec_file->f_path.dentry;
	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
	dentry = lookup_one_len(name, dir, namlen);
	if (IS_ERR(dentry)) {
		status = PTR_ERR(dentry);
		goto out_unlock;
	}
	status = -ENOENT;
	if (!dentry->d_inode)
		goto out;
	status = vfs_rmdir(dir->d_inode, dentry);
out:
	dput(dentry);
out_unlock:
	mutex_unlock(&dir->d_inode->i_mutex);
	return status;
}

void
nfsd4_remove_clid_dir(struct nfs4_client *clp)
{
	const struct cred *original_cred;
	int status;

	if (!rec_file || !clp->cl_firststate)
		return;

	status = mnt_want_write(rec_file->f_path.mnt);
	if (status)
		goto out;
	clp->cl_firststate = 0;

	status = nfs4_save_creds(&original_cred);
	if (status < 0)
		goto out;

	status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
	nfs4_reset_creds(original_cred);
	if (status == 0)
		vfs_fsync(rec_file, 0);
	mnt_drop_write(rec_file->f_path.mnt);
out:
	if (status)
		printk("NFSD: Failed to remove expired client state directory"
				" %.*s\n", HEXDIR_LEN, clp->cl_recdir);
	return;
}

static int
purge_old(struct dentry *parent, struct dentry *child)
{
	int status;

	if (nfs4_has_reclaimed_state(child->d_name.name, false))
		return 0;

	status = vfs_rmdir(parent->d_inode, child);
	if (status)
		printk("failed to remove client recovery directory %s\n",
				child->d_name.name);
	/* Keep trying, success or failure: */
	return 0;
}

void
nfsd4_recdir_purge_old(void) {
	int status;

	if (!rec_file)
		return;
	status = mnt_want_write(rec_file->f_path.mnt);
	if (status)
		goto out;
	status = nfsd4_list_rec_dir(purge_old);
	if (status == 0)
		vfs_fsync(rec_file, 0);
	mnt_drop_write(rec_file->f_path.mnt);
out:
	if (status)
		printk("nfsd4: failed to purge old clients from recovery"
			" directory %s\n", rec_file->f_path.dentry->d_name.name);
}

static int
load_recdir(struct dentry *parent, struct dentry *child)
{
	if (child->d_name.len != HEXDIR_LEN - 1) {
		printk("nfsd4: illegal name %s in recovery directory\n",
				child->d_name.name);
		/* Keep trying; maybe the others are OK: */
		return 0;
	}
	nfs4_client_to_reclaim(child->d_name.name);
	return 0;
}

int
nfsd4_recdir_load(void) {
	int status;

	if (!rec_file)
		return 0;

	status = nfsd4_list_rec_dir(load_recdir);
	if (status)
		printk("nfsd4: failed loading clients from recovery"
			" directory %s\n", rec_file->f_path.dentry->d_name.name);
	return status;
}

/*
 * Hold reference to the recovery directory.
 */

void
nfsd4_init_recdir()
{
	const struct cred *original_cred;
	int status;

	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
			user_recovery_dirname);

	BUG_ON(rec_file);

	status = nfs4_save_creds(&original_cred);
	if (status < 0) {
		printk("NFSD: Unable to change credentials to find recovery"
		       " directory: error %d\n",
		       status);
		return;
	}

	rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
	if (IS_ERR(rec_file)) {
		printk("NFSD: unable to find recovery directory %s\n",
				user_recovery_dirname);
		rec_file = NULL;
	}

	nfs4_reset_creds(original_cred);
}

void
nfsd4_shutdown_recdir(void)
{
	if (!rec_file)
		return;
	fput(rec_file);
	rec_file = NULL;
}

/*
 * Change the NFSv4 recovery directory to recdir.
 */
int
nfs4_reset_recoverydir(char *recdir)
{
	int status;
	struct path path;

	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
	if (status)
		return status;
	status = -ENOTDIR;
	if (S_ISDIR(path.dentry->d_inode->i_mode)) {
		strcpy(user_recovery_dirname, recdir);
		status = 0;
	}
	path_put(&path);
	return status;
}

char *
nfs4_recoverydir(void)
{
	return user_recovery_dirname;
}
OpenPOWER on IntegriCloud