Update fs/ to use sg helpers
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nfsd / nfs4recover.c
CommitLineData
a55370a3
N
1/*
2* linux/fs/nfsd/nfs4recover.c
3*
4* Copyright (c) 2004 The Regents of the University of Michigan.
5* All rights reserved.
6*
7* Andy Adamson <andros@citi.umich.edu>
8*
9* Redistribution and use in source and binary forms, with or without
10* modification, are permitted provided that the following conditions
11* are met:
12*
13* 1. Redistributions of source code must retain the above copyright
14* notice, this list of conditions and the following disclaimer.
15* 2. Redistributions in binary form must reproduce the above copyright
16* notice, this list of conditions and the following disclaimer in the
17* documentation and/or other materials provided with the distribution.
18* 3. Neither the name of the University nor the names of its
19* contributors may be used to endorse or promote products derived
20* from this software without specific prior written permission.
21*
22* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33*
34*/
35
35058687 36#include <linux/err.h>
a55370a3
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37#include <linux/sunrpc/svc.h>
38#include <linux/nfsd/nfsd.h>
39#include <linux/nfs4.h>
40#include <linux/nfsd/state.h>
41#include <linux/nfsd/xdr4.h>
190e4fbf
N
42#include <linux/param.h>
43#include <linux/file.h>
44#include <linux/namei.h>
a55370a3
N
45#include <asm/uaccess.h>
46#include <asm/scatterlist.h>
47#include <linux/crypto.h>
e8edc6e0 48#include <linux/sched.h>
a55370a3
N
49
50#define NFSDDBG_FACILITY NFSDDBG_PROC
51
190e4fbf 52/* Globals */
190e4fbf
N
53static struct nameidata rec_dir;
54static int rec_dir_init = 0;
55
56static void
57nfs4_save_user(uid_t *saveuid, gid_t *savegid)
58{
59 *saveuid = current->fsuid;
60 *savegid = current->fsgid;
61 current->fsuid = 0;
62 current->fsgid = 0;
63}
64
65static void
66nfs4_reset_user(uid_t saveuid, gid_t savegid)
67{
68 current->fsuid = saveuid;
69 current->fsgid = savegid;
70}
71
a55370a3
N
72static void
73md5_to_hex(char *out, char *md5)
74{
75 int i;
76
77 for (i=0; i<16; i++) {
78 unsigned char c = md5[i];
79
80 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
81 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
82 }
83 *out = '\0';
84}
85
b37ad28b 86__be32
a55370a3
N
87nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
88{
89 struct xdr_netobj cksum;
35058687 90 struct hash_desc desc;
60c74f81 91 struct scatterlist sg;
b37ad28b 92 __be32 status = nfserr_resource;
a55370a3
N
93
94 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
95 clname->len, clname->data);
35058687
HX
96 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
97 desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
98 if (IS_ERR(desc.tfm))
99 goto out_no_tfm;
100 cksum.len = crypto_hash_digestsize(desc.tfm);
a55370a3
N
101 cksum.data = kmalloc(cksum.len, GFP_KERNEL);
102 if (cksum.data == NULL)
103 goto out;
a55370a3 104
60c74f81 105 sg_init_one(&sg, clname->data, clname->len);
a55370a3 106
60c74f81 107 if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data))
35058687 108 goto out;
a55370a3
N
109
110 md5_to_hex(dname, cksum.data);
111
112 kfree(cksum.data);
113 status = nfs_ok;
114out:
35058687
HX
115 crypto_free_hash(desc.tfm);
116out_no_tfm:
a55370a3
N
117 return status;
118}
190e4fbf 119
a6ccbbb8
N
120static void
121nfsd4_sync_rec_dir(void)
c7b9a459 122{
1b1dcc1b 123 mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
a6ccbbb8 124 nfsd_sync_dir(rec_dir.dentry);
1b1dcc1b 125 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459
N
126}
127
128int
129nfsd4_create_clid_dir(struct nfs4_client *clp)
130{
131 char *dname = clp->cl_recdir;
132 struct dentry *dentry;
133 uid_t uid;
134 gid_t gid;
135 int status;
136
137 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
138
139 if (!rec_dir_init || clp->cl_firststate)
140 return 0;
141
142 nfs4_save_user(&uid, &gid);
143
144 /* lock the parent */
1b1dcc1b 145 mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459
N
146
147 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
148 if (IS_ERR(dentry)) {
149 status = PTR_ERR(dentry);
150 goto out_unlock;
151 }
152 status = -EEXIST;
153 if (dentry->d_inode) {
154 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
155 goto out_put;
156 }
157 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
158out_put:
159 dput(dentry);
160out_unlock:
1b1dcc1b 161 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459
N
162 if (status == 0) {
163 clp->cl_firststate = 1;
a6ccbbb8 164 nfsd4_sync_rec_dir();
c7b9a459
N
165 }
166 nfs4_reset_user(uid, gid);
167 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
168 return status;
169}
170
190e4fbf
N
171typedef int (recdir_func)(struct dentry *, struct dentry *);
172
173struct dentry_list {
174 struct dentry *dentry;
175 struct list_head list;
176};
177
178struct dentry_list_arg {
179 struct list_head dentries;
180 struct dentry *parent;
181};
182
183static int
184nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
afefdbb2 185 loff_t offset, u64 ino, unsigned int d_type)
190e4fbf
N
186{
187 struct dentry_list_arg *dla = arg;
188 struct list_head *dentries = &dla->dentries;
189 struct dentry *parent = dla->parent;
190 struct dentry *dentry;
191 struct dentry_list *child;
192
193 if (name && isdotent(name, namlen))
b37ad28b 194 return 0;
190e4fbf
N
195 dentry = lookup_one_len(name, parent, namlen);
196 if (IS_ERR(dentry))
197 return PTR_ERR(dentry);
198 child = kmalloc(sizeof(*child), GFP_KERNEL);
199 if (child == NULL)
200 return -ENOMEM;
201 child->dentry = dentry;
202 list_add(&child->list, dentries);
203 return 0;
204}
205
206static int
207nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
208{
209 struct file *filp;
210 struct dentry_list_arg dla = {
211 .parent = dir,
212 };
213 struct list_head *dentries = &dla.dentries;
214 struct dentry_list *child;
215 uid_t uid;
216 gid_t gid;
217 int status;
218
219 if (!rec_dir_init)
220 return 0;
221
222 nfs4_save_user(&uid, &gid);
223
d22749b6 224 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY);
190e4fbf
N
225 status = PTR_ERR(filp);
226 if (IS_ERR(filp))
227 goto out;
228 INIT_LIST_HEAD(dentries);
229 status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
230 fput(filp);
231 while (!list_empty(dentries)) {
232 child = list_entry(dentries->next, struct dentry_list, list);
233 status = f(dir, child->dentry);
234 if (status)
235 goto out;
236 list_del(&child->list);
237 dput(child->dentry);
238 kfree(child);
239 }
240out:
241 while (!list_empty(dentries)) {
242 child = list_entry(dentries->next, struct dentry_list, list);
243 list_del(&child->list);
244 dput(child->dentry);
245 kfree(child);
246 }
247 nfs4_reset_user(uid, gid);
248 return status;
249}
250
c7b9a459
N
251static int
252nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
253{
254 int status;
255
256 if (!S_ISREG(dir->d_inode->i_mode)) {
257 printk("nfsd4: non-file found in client recovery directory\n");
258 return -EINVAL;
259 }
4b75f78e 260 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459 261 status = vfs_unlink(dir->d_inode, dentry);
1b1dcc1b 262 mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459
N
263 return status;
264}
265
266static int
267nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
268{
269 int status;
270
271 /* For now this directory should already be empty, but we empty it of
272 * any regular files anyway, just in case the directory was created by
273 * a kernel from the future.... */
274 nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
7ef55b8a 275 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
c7b9a459 276 status = vfs_rmdir(dir->d_inode, dentry);
1b1dcc1b 277 mutex_unlock(&dir->d_inode->i_mutex);
c7b9a459
N
278 return status;
279}
280
281static int
282nfsd4_unlink_clid_dir(char *name, int namlen)
283{
284 struct dentry *dentry;
285 int status;
286
287 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
288
1b1dcc1b 289 mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459 290 dentry = lookup_one_len(name, rec_dir.dentry, namlen);
1b1dcc1b 291 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
c7b9a459
N
292 if (IS_ERR(dentry)) {
293 status = PTR_ERR(dentry);
294 return status;
295 }
296 status = -ENOENT;
297 if (!dentry->d_inode)
298 goto out;
299
300 status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
301out:
302 dput(dentry);
303 return status;
304}
305
306void
307nfsd4_remove_clid_dir(struct nfs4_client *clp)
308{
309 uid_t uid;
310 gid_t gid;
311 int status;
312
313 if (!rec_dir_init || !clp->cl_firststate)
314 return;
315
67be4313 316 clp->cl_firststate = 0;
c7b9a459
N
317 nfs4_save_user(&uid, &gid);
318 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
319 nfs4_reset_user(uid, gid);
320 if (status == 0)
a6ccbbb8 321 nfsd4_sync_rec_dir();
c7b9a459
N
322 if (status)
323 printk("NFSD: Failed to remove expired client state directory"
324 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
325 return;
326}
327
328static int
329purge_old(struct dentry *parent, struct dentry *child)
330{
331 int status;
332
333 if (nfs4_has_reclaimed_state(child->d_name.name))
b37ad28b 334 return 0;
c7b9a459
N
335
336 status = nfsd4_clear_clid_dir(parent, child);
337 if (status)
338 printk("failed to remove client recovery directory %s\n",
339 child->d_name.name);
340 /* Keep trying, success or failure: */
b37ad28b 341 return 0;
c7b9a459
N
342}
343
344void
345nfsd4_recdir_purge_old(void) {
346 int status;
347
348 if (!rec_dir_init)
349 return;
350 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
351 if (status == 0)
a6ccbbb8 352 nfsd4_sync_rec_dir();
c7b9a459
N
353 if (status)
354 printk("nfsd4: failed to purge old clients from recovery"
355 " directory %s\n", rec_dir.dentry->d_name.name);
356 return;
357}
358
190e4fbf
N
359static int
360load_recdir(struct dentry *parent, struct dentry *child)
361{
362 if (child->d_name.len != HEXDIR_LEN - 1) {
363 printk("nfsd4: illegal name %s in recovery directory\n",
364 child->d_name.name);
365 /* Keep trying; maybe the others are OK: */
b37ad28b 366 return 0;
190e4fbf
N
367 }
368 nfs4_client_to_reclaim(child->d_name.name);
b37ad28b 369 return 0;
190e4fbf
N
370}
371
372int
373nfsd4_recdir_load(void) {
374 int status;
375
376 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
377 if (status)
378 printk("nfsd4: failed loading clients from recovery"
379 " directory %s\n", rec_dir.dentry->d_name.name);
380 return status;
381}
382
383/*
384 * Hold reference to the recovery directory.
385 */
386
387void
388nfsd4_init_recdir(char *rec_dirname)
389{
390 uid_t uid = 0;
391 gid_t gid = 0;
392 int status;
393
394 printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
395 rec_dirname);
396
397 BUG_ON(rec_dir_init);
398
399 nfs4_save_user(&uid, &gid);
400
c2642ab0
BF
401 status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
402 &rec_dir);
403 if (status)
404 printk("NFSD: unable to find recovery directory %s\n",
190e4fbf
N
405 rec_dirname);
406
407 if (!status)
408 rec_dir_init = 1;
409 nfs4_reset_user(uid, gid);
410}
411
412void
413nfsd4_shutdown_recdir(void)
414{
415 if (!rec_dir_init)
416 return;
417 rec_dir_init = 0;
418 path_release(&rec_dir);
419}