[PATCH] nfsd4: lookup_one_len takes i_sem
[deliverable/linux.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
36
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>
48
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
86int
87nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
88{
89 struct xdr_netobj cksum;
90 struct crypto_tfm *tfm;
91 struct scatterlist sg[1];
92 int status = nfserr_resource;
93
94 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
95 clname->len, clname->data);
96 tfm = crypto_alloc_tfm("md5", 0);
97 if (tfm == NULL)
98 goto out;
99 cksum.len = crypto_tfm_alg_digestsize(tfm);
100 cksum.data = kmalloc(cksum.len, GFP_KERNEL);
101 if (cksum.data == NULL)
102 goto out;
103 crypto_digest_init(tfm);
104
105 sg[0].page = virt_to_page(clname->data);
106 sg[0].offset = offset_in_page(clname->data);
107 sg[0].length = clname->len;
108
109 crypto_digest_update(tfm, sg, 1);
110 crypto_digest_final(tfm, cksum.data);
111
112 md5_to_hex(dname, cksum.data);
113
114 kfree(cksum.data);
115 status = nfs_ok;
116out:
117 if (tfm)
118 crypto_free_tfm(tfm);
119 return status;
120}
190e4fbf 121
a6ccbbb8
N
122static void
123nfsd4_sync_rec_dir(void)
c7b9a459 124{
a6ccbbb8
N
125 down(&rec_dir.dentry->d_inode->i_sem);
126 nfsd_sync_dir(rec_dir.dentry);
127 up(&rec_dir.dentry->d_inode->i_sem);
c7b9a459
N
128}
129
130int
131nfsd4_create_clid_dir(struct nfs4_client *clp)
132{
133 char *dname = clp->cl_recdir;
134 struct dentry *dentry;
135 uid_t uid;
136 gid_t gid;
137 int status;
138
139 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
140
141 if (!rec_dir_init || clp->cl_firststate)
142 return 0;
143
144 nfs4_save_user(&uid, &gid);
145
146 /* lock the parent */
147 down(&rec_dir.dentry->d_inode->i_sem);
148
149 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
150 if (IS_ERR(dentry)) {
151 status = PTR_ERR(dentry);
152 goto out_unlock;
153 }
154 status = -EEXIST;
155 if (dentry->d_inode) {
156 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
157 goto out_put;
158 }
159 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
160out_put:
161 dput(dentry);
162out_unlock:
163 up(&rec_dir.dentry->d_inode->i_sem);
164 if (status == 0) {
165 clp->cl_firststate = 1;
a6ccbbb8 166 nfsd4_sync_rec_dir();
c7b9a459
N
167 }
168 nfs4_reset_user(uid, gid);
169 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
170 return status;
171}
172
190e4fbf
N
173typedef int (recdir_func)(struct dentry *, struct dentry *);
174
175struct dentry_list {
176 struct dentry *dentry;
177 struct list_head list;
178};
179
180struct dentry_list_arg {
181 struct list_head dentries;
182 struct dentry *parent;
183};
184
185static int
186nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
187 loff_t offset, ino_t ino, unsigned int d_type)
188{
189 struct dentry_list_arg *dla = arg;
190 struct list_head *dentries = &dla->dentries;
191 struct dentry *parent = dla->parent;
192 struct dentry *dentry;
193 struct dentry_list *child;
194
195 if (name && isdotent(name, namlen))
196 return nfs_ok;
197 dentry = lookup_one_len(name, parent, namlen);
198 if (IS_ERR(dentry))
199 return PTR_ERR(dentry);
200 child = kmalloc(sizeof(*child), GFP_KERNEL);
201 if (child == NULL)
202 return -ENOMEM;
203 child->dentry = dentry;
204 list_add(&child->list, dentries);
205 return 0;
206}
207
208static int
209nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
210{
211 struct file *filp;
212 struct dentry_list_arg dla = {
213 .parent = dir,
214 };
215 struct list_head *dentries = &dla.dentries;
216 struct dentry_list *child;
217 uid_t uid;
218 gid_t gid;
219 int status;
220
221 if (!rec_dir_init)
222 return 0;
223
224 nfs4_save_user(&uid, &gid);
225
226 filp = dentry_open(dget(dir), mntget(rec_dir.mnt),
227 O_RDWR);
228 status = PTR_ERR(filp);
229 if (IS_ERR(filp))
230 goto out;
231 INIT_LIST_HEAD(dentries);
232 status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
233 fput(filp);
234 while (!list_empty(dentries)) {
235 child = list_entry(dentries->next, struct dentry_list, list);
236 status = f(dir, child->dentry);
237 if (status)
238 goto out;
239 list_del(&child->list);
240 dput(child->dentry);
241 kfree(child);
242 }
243out:
244 while (!list_empty(dentries)) {
245 child = list_entry(dentries->next, struct dentry_list, list);
246 list_del(&child->list);
247 dput(child->dentry);
248 kfree(child);
249 }
250 nfs4_reset_user(uid, gid);
251 return status;
252}
253
c7b9a459
N
254static int
255nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
256{
257 int status;
258
259 if (!S_ISREG(dir->d_inode->i_mode)) {
260 printk("nfsd4: non-file found in client recovery directory\n");
261 return -EINVAL;
262 }
263 down(&dir->d_inode->i_sem);
264 status = vfs_unlink(dir->d_inode, dentry);
265 up(&dir->d_inode->i_sem);
266 return status;
267}
268
269static int
270nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
271{
272 int status;
273
274 /* For now this directory should already be empty, but we empty it of
275 * any regular files anyway, just in case the directory was created by
276 * a kernel from the future.... */
277 nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
278 down(&dir->d_inode->i_sem);
279 status = vfs_rmdir(dir->d_inode, dentry);
280 up(&dir->d_inode->i_sem);
281 return status;
282}
283
284static int
285nfsd4_unlink_clid_dir(char *name, int namlen)
286{
287 struct dentry *dentry;
288 int status;
289
290 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
291
cdc5524e 292 down(&rec_dir.dentry->d_inode->i_sem);
c7b9a459 293 dentry = lookup_one_len(name, rec_dir.dentry, namlen);
cdc5524e 294 up(&rec_dir.dentry->d_inode->i_sem);
c7b9a459
N
295 if (IS_ERR(dentry)) {
296 status = PTR_ERR(dentry);
297 return status;
298 }
299 status = -ENOENT;
300 if (!dentry->d_inode)
301 goto out;
302
303 status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
304out:
305 dput(dentry);
306 return status;
307}
308
309void
310nfsd4_remove_clid_dir(struct nfs4_client *clp)
311{
312 uid_t uid;
313 gid_t gid;
314 int status;
315
316 if (!rec_dir_init || !clp->cl_firststate)
317 return;
318
319 nfs4_save_user(&uid, &gid);
320 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
321 nfs4_reset_user(uid, gid);
322 if (status == 0)
a6ccbbb8 323 nfsd4_sync_rec_dir();
c7b9a459
N
324 if (status)
325 printk("NFSD: Failed to remove expired client state directory"
326 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
327 return;
328}
329
330static int
331purge_old(struct dentry *parent, struct dentry *child)
332{
333 int status;
334
335 if (nfs4_has_reclaimed_state(child->d_name.name))
336 return nfs_ok;
337
338 status = nfsd4_clear_clid_dir(parent, child);
339 if (status)
340 printk("failed to remove client recovery directory %s\n",
341 child->d_name.name);
342 /* Keep trying, success or failure: */
343 return nfs_ok;
344}
345
346void
347nfsd4_recdir_purge_old(void) {
348 int status;
349
350 if (!rec_dir_init)
351 return;
352 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
353 if (status == 0)
a6ccbbb8 354 nfsd4_sync_rec_dir();
c7b9a459
N
355 if (status)
356 printk("nfsd4: failed to purge old clients from recovery"
357 " directory %s\n", rec_dir.dentry->d_name.name);
358 return;
359}
360
190e4fbf
N
361static int
362load_recdir(struct dentry *parent, struct dentry *child)
363{
364 if (child->d_name.len != HEXDIR_LEN - 1) {
365 printk("nfsd4: illegal name %s in recovery directory\n",
366 child->d_name.name);
367 /* Keep trying; maybe the others are OK: */
368 return nfs_ok;
369 }
370 nfs4_client_to_reclaim(child->d_name.name);
371 return nfs_ok;
372}
373
374int
375nfsd4_recdir_load(void) {
376 int status;
377
378 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
379 if (status)
380 printk("nfsd4: failed loading clients from recovery"
381 " directory %s\n", rec_dir.dentry->d_name.name);
382 return status;
383}
384
385/*
386 * Hold reference to the recovery directory.
387 */
388
389void
390nfsd4_init_recdir(char *rec_dirname)
391{
392 uid_t uid = 0;
393 gid_t gid = 0;
394 int status;
395
396 printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
397 rec_dirname);
398
399 BUG_ON(rec_dir_init);
400
401 nfs4_save_user(&uid, &gid);
402
403 status = path_lookup(rec_dirname, LOOKUP_FOLLOW, &rec_dir);
404 if (status == -ENOENT)
405 printk("NFSD: recovery directory %s doesn't exist\n",
406 rec_dirname);
407
408 if (!status)
409 rec_dir_init = 1;
410 nfs4_reset_user(uid, gid);
411}
412
413void
414nfsd4_shutdown_recdir(void)
415{
416 if (!rec_dir_init)
417 return;
418 rec_dir_init = 0;
419 path_release(&rec_dir);
420}
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