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9p: switch v9fs_set_acl() from dentry to fid
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1/*
2 * Copyright IBM Corporation, 2010
3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/fs.h>
17#include <net/9p/9p.h>
18#include <net/9p/client.h>
19#include <linux/slab.h>
22d8dcdf 20#include <linux/sched.h>
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21#include <linux/posix_acl_xattr.h>
22#include "xattr.h"
23#include "acl.h"
76381a42 24#include "v9fs.h"
5ffc0cb3 25#include "v9fs_vfs.h"
0f235cae 26#include "fid.h"
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27
28static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
29{
30 ssize_t size;
31 void *value = NULL;
009ca389 32 struct posix_acl *acl = NULL;
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33
34 size = v9fs_fid_xattr_get(fid, name, NULL, 0);
35 if (size > 0) {
36 value = kzalloc(size, GFP_NOFS);
37 if (!value)
38 return ERR_PTR(-ENOMEM);
39 size = v9fs_fid_xattr_get(fid, name, value, size);
40 if (size > 0) {
5f3a4a28 41 acl = posix_acl_from_xattr(&init_user_ns, value, size);
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42 if (IS_ERR(acl))
43 goto err_out;
44 }
45 } else if (size == -ENODATA || size == 0 ||
46 size == -ENOSYS || size == -EOPNOTSUPP) {
47 acl = NULL;
48 } else
49 acl = ERR_PTR(-EIO);
50
51err_out:
52 kfree(value);
53 return acl;
54}
55
56int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
57{
58 int retval = 0;
59 struct posix_acl *pacl, *dacl;
76381a42 60 struct v9fs_session_info *v9ses;
85ff872d 61
76381a42 62 v9ses = v9fs_inode2v9ses(inode);
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63 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
64 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
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65 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
66 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
67 return 0;
68 }
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69 /* get the default/access acl values and cache them */
70 dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
71 pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
72
73 if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
74 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
75 set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
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76 } else
77 retval = -EIO;
78
c61fa0d6
VJJ
79 if (!IS_ERR(dacl))
80 posix_acl_release(dacl);
81
82 if (!IS_ERR(pacl))
83 posix_acl_release(pacl);
84
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85 return retval;
86}
87
88static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
89{
90 struct posix_acl *acl;
91 /*
92 * 9p Always cache the acl value when
93 * instantiating the inode (v9fs_inode_from_fid)
94 */
95 acl = get_cached_acl(inode, type);
96 BUG_ON(acl == ACL_NOT_CACHED);
97 return acl;
98}
99
4e34e719 100struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type)
85ff872d 101{
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102 struct v9fs_session_info *v9ses;
103
104 v9ses = v9fs_inode2v9ses(inode);
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105 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
106 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
76381a42 107 /*
e782ef71 108 * On access = client and acl = on mode get the acl
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109 * values from the server
110 */
4e34e719 111 return NULL;
76381a42 112 }
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113 return v9fs_get_cached_acl(inode, type);
114
85ff872d 115}
7a4566b0 116
0f235cae 117static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
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118{
119 int retval;
120 char *name;
121 size_t size;
122 void *buffer;
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123 if (!acl)
124 return 0;
125
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126 /* Set a setxattr request to server */
127 size = posix_acl_xattr_size(acl->a_count);
128 buffer = kmalloc(size, GFP_KERNEL);
129 if (!buffer)
130 return -ENOMEM;
5f3a4a28 131 retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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132 if (retval < 0)
133 goto err_free_out;
134 switch (type) {
135 case ACL_TYPE_ACCESS:
136 name = POSIX_ACL_XATTR_ACCESS;
137 break;
138 case ACL_TYPE_DEFAULT:
139 name = POSIX_ACL_XATTR_DEFAULT;
140 break;
141 default:
142 BUG();
143 }
0f235cae 144 retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0);
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145err_free_out:
146 kfree(buffer);
147 return retval;
148}
149
150int v9fs_acl_chmod(struct dentry *dentry)
151{
152 int retval = 0;
bc26ab5f 153 struct posix_acl *acl;
6e8dc555 154 struct inode *inode = dentry->d_inode;
0f235cae 155 struct p9_fid *fid = v9fs_fid_lookup(dentry);
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156
157 if (S_ISLNK(inode->i_mode))
158 return -EOPNOTSUPP;
0f235cae
AV
159 if (IS_ERR(fid))
160 return PTR_ERR(fid);
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161 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
162 if (acl) {
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163 retval = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
164 if (retval)
165 return retval;
7f165aaa 166 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
0f235cae 167 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
6e8dc555 168 posix_acl_release(acl);
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169 }
170 return retval;
171}
172
ad77dbce 173int v9fs_set_create_acl(struct dentry *dentry,
1ec95bf3 174 struct posix_acl **dpacl, struct posix_acl **pacl)
ad77dbce 175{
1ec95bf3 176 if (dentry) {
0f235cae 177 struct p9_fid *fid = v9fs_fid_lookup(dentry);
7f165aaa 178 set_cached_acl(dentry->d_inode, ACL_TYPE_DEFAULT, *dpacl);
7f165aaa 179 set_cached_acl(dentry->d_inode, ACL_TYPE_ACCESS, *pacl);
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180 if (!IS_ERR(fid)) {
181 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, *dpacl);
182 v9fs_set_acl(fid, ACL_TYPE_ACCESS, *pacl);
183 }
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184 }
185 posix_acl_release(*dpacl);
186 posix_acl_release(*pacl);
187 *dpacl = *pacl = NULL;
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188 return 0;
189}
190
d3fb6120 191int v9fs_acl_mode(struct inode *dir, umode_t *modep,
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192 struct posix_acl **dpacl, struct posix_acl **pacl)
193{
194 int retval = 0;
d3fb6120 195 umode_t mode = *modep;
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196 struct posix_acl *acl = NULL;
197
198 if (!S_ISLNK(mode)) {
199 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
200 if (IS_ERR(acl))
201 return PTR_ERR(acl);
202 if (!acl)
203 mode &= ~current_umask();
204 }
205 if (acl) {
ad77dbce 206 if (S_ISDIR(mode))
1ec95bf3 207 *dpacl = posix_acl_dup(acl);
826cae2f
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208 retval = posix_acl_create(&acl, GFP_NOFS, &mode);
209 if (retval < 0)
210 return retval;
ad77dbce 211 if (retval > 0)
826cae2f 212 *pacl = acl;
1ec95bf3 213 else
826cae2f 214 posix_acl_release(acl);
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215 }
216 *modep = mode;
217 return 0;
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218}
219
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220static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
221 void *buffer, size_t size, int type)
222{
223 char *full_name;
224
225 switch (type) {
226 case ACL_TYPE_ACCESS:
227 full_name = POSIX_ACL_XATTR_ACCESS;
228 break;
229 case ACL_TYPE_DEFAULT:
230 full_name = POSIX_ACL_XATTR_DEFAULT;
231 break;
232 default:
233 BUG();
234 }
235 return v9fs_xattr_get(dentry, full_name, buffer, size);
236}
237
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238static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
239 void *buffer, size_t size, int type)
240{
76381a42 241 struct v9fs_session_info *v9ses;
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242 struct posix_acl *acl;
243 int error;
244
245 if (strcmp(name, "") != 0)
246 return -EINVAL;
247
42869c8a 248 v9ses = v9fs_dentry2v9ses(dentry);
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249 /*
250 * We allow set/get/list of acl when access=client is not specified
251 */
252 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
253 return v9fs_remote_get_acl(dentry, name, buffer, size, type);
254
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255 acl = v9fs_get_cached_acl(dentry->d_inode, type);
256 if (IS_ERR(acl))
257 return PTR_ERR(acl);
258 if (acl == NULL)
259 return -ENODATA;
5f3a4a28 260 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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261 posix_acl_release(acl);
262
263 return error;
264}
265
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266static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
267 const void *value, size_t size,
268 int flags, int type)
269{
270 char *full_name;
271
272 switch (type) {
273 case ACL_TYPE_ACCESS:
274 full_name = POSIX_ACL_XATTR_ACCESS;
275 break;
276 case ACL_TYPE_DEFAULT:
277 full_name = POSIX_ACL_XATTR_DEFAULT;
278 break;
279 default:
280 BUG();
281 }
282 return v9fs_xattr_set(dentry, full_name, value, size, flags);
283}
284
285
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286static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
287 const void *value, size_t size,
288 int flags, int type)
289{
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290 int retval;
291 struct posix_acl *acl;
76381a42 292 struct v9fs_session_info *v9ses;
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293 struct inode *inode = dentry->d_inode;
294
295 if (strcmp(name, "") != 0)
296 return -EINVAL;
76381a42 297
42869c8a 298 v9ses = v9fs_dentry2v9ses(dentry);
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299 /*
300 * set the attribute on the remote. Without even looking at the
301 * xattr value. We leave it to the server to validate
302 */
303 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
304 return v9fs_remote_set_acl(dentry, name,
305 value, size, flags, type);
306
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307 if (S_ISLNK(inode->i_mode))
308 return -EOPNOTSUPP;
2e149670 309 if (!inode_owner_or_capable(inode))
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310 return -EPERM;
311 if (value) {
312 /* update the cached acl value */
5f3a4a28 313 acl = posix_acl_from_xattr(&init_user_ns, value, size);
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314 if (IS_ERR(acl))
315 return PTR_ERR(acl);
316 else if (acl) {
317 retval = posix_acl_valid(acl);
318 if (retval)
319 goto err_out;
320 }
321 } else
322 acl = NULL;
323
324 switch (type) {
325 case ACL_TYPE_ACCESS:
326 name = POSIX_ACL_XATTR_ACCESS;
327 if (acl) {
d6952123 328 umode_t mode = inode->i_mode;
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329 retval = posix_acl_equiv_mode(acl, &mode);
330 if (retval < 0)
331 goto err_out;
332 else {
333 struct iattr iattr;
334 if (retval == 0) {
335 /*
336 * ACL can be represented
337 * by the mode bits. So don't
338 * update ACL.
339 */
340 acl = NULL;
341 value = NULL;
342 size = 0;
343 }
344 /* Updte the mode bits */
345 iattr.ia_mode = ((mode & S_IALLUGO) |
346 (inode->i_mode & ~S_IALLUGO));
347 iattr.ia_valid = ATTR_MODE;
348 /* FIXME should we update ctime ?
349 * What is the following setxattr update the
350 * mode ?
351 */
352 v9fs_vfs_setattr_dotl(dentry, &iattr);
353 }
354 }
355 break;
356 case ACL_TYPE_DEFAULT:
357 name = POSIX_ACL_XATTR_DEFAULT;
358 if (!S_ISDIR(inode->i_mode)) {
6f81c115 359 retval = acl ? -EINVAL : 0;
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360 goto err_out;
361 }
362 break;
363 default:
364 BUG();
365 }
366 retval = v9fs_xattr_set(dentry, name, value, size, flags);
367 if (!retval)
368 set_cached_acl(inode, type, acl);
369err_out:
370 posix_acl_release(acl);
371 return retval;
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372}
373
374const struct xattr_handler v9fs_xattr_acl_access_handler = {
375 .prefix = POSIX_ACL_XATTR_ACCESS,
376 .flags = ACL_TYPE_ACCESS,
377 .get = v9fs_xattr_get_acl,
378 .set = v9fs_xattr_set_acl,
379};
380
381const struct xattr_handler v9fs_xattr_acl_default_handler = {
382 .prefix = POSIX_ACL_XATTR_DEFAULT,
383 .flags = ACL_TYPE_DEFAULT,
384 .get = v9fs_xattr_get_acl,
385 .set = v9fs_xattr_set_acl,
386};