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9p: switch v9fs_acl_chmod() from dentry to inode+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
be308f07 150int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)
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151{
152 int retval = 0;
bc26ab5f 153 struct posix_acl *acl;
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154
155 if (S_ISLNK(inode->i_mode))
156 return -EOPNOTSUPP;
157 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
158 if (acl) {
bc26ab5f
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159 retval = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
160 if (retval)
161 return retval;
7f165aaa 162 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
0f235cae 163 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
6e8dc555 164 posix_acl_release(acl);
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165 }
166 return retval;
167}
168
ad77dbce 169int v9fs_set_create_acl(struct dentry *dentry,
1ec95bf3 170 struct posix_acl **dpacl, struct posix_acl **pacl)
ad77dbce 171{
1ec95bf3 172 if (dentry) {
0f235cae 173 struct p9_fid *fid = v9fs_fid_lookup(dentry);
7f165aaa 174 set_cached_acl(dentry->d_inode, ACL_TYPE_DEFAULT, *dpacl);
7f165aaa 175 set_cached_acl(dentry->d_inode, ACL_TYPE_ACCESS, *pacl);
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176 if (!IS_ERR(fid)) {
177 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, *dpacl);
178 v9fs_set_acl(fid, ACL_TYPE_ACCESS, *pacl);
179 }
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180 }
181 posix_acl_release(*dpacl);
182 posix_acl_release(*pacl);
183 *dpacl = *pacl = NULL;
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184 return 0;
185}
186
d3fb6120 187int v9fs_acl_mode(struct inode *dir, umode_t *modep,
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188 struct posix_acl **dpacl, struct posix_acl **pacl)
189{
190 int retval = 0;
d3fb6120 191 umode_t mode = *modep;
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192 struct posix_acl *acl = NULL;
193
194 if (!S_ISLNK(mode)) {
195 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
196 if (IS_ERR(acl))
197 return PTR_ERR(acl);
198 if (!acl)
199 mode &= ~current_umask();
200 }
201 if (acl) {
ad77dbce 202 if (S_ISDIR(mode))
1ec95bf3 203 *dpacl = posix_acl_dup(acl);
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204 retval = posix_acl_create(&acl, GFP_NOFS, &mode);
205 if (retval < 0)
206 return retval;
ad77dbce 207 if (retval > 0)
826cae2f 208 *pacl = acl;
1ec95bf3 209 else
826cae2f 210 posix_acl_release(acl);
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211 }
212 *modep = mode;
213 return 0;
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214}
215
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216static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
217 void *buffer, size_t size, int type)
218{
219 char *full_name;
220
221 switch (type) {
222 case ACL_TYPE_ACCESS:
223 full_name = POSIX_ACL_XATTR_ACCESS;
224 break;
225 case ACL_TYPE_DEFAULT:
226 full_name = POSIX_ACL_XATTR_DEFAULT;
227 break;
228 default:
229 BUG();
230 }
231 return v9fs_xattr_get(dentry, full_name, buffer, size);
232}
233
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234static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
235 void *buffer, size_t size, int type)
236{
76381a42 237 struct v9fs_session_info *v9ses;
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238 struct posix_acl *acl;
239 int error;
240
241 if (strcmp(name, "") != 0)
242 return -EINVAL;
243
42869c8a 244 v9ses = v9fs_dentry2v9ses(dentry);
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245 /*
246 * We allow set/get/list of acl when access=client is not specified
247 */
248 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
249 return v9fs_remote_get_acl(dentry, name, buffer, size, type);
250
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251 acl = v9fs_get_cached_acl(dentry->d_inode, type);
252 if (IS_ERR(acl))
253 return PTR_ERR(acl);
254 if (acl == NULL)
255 return -ENODATA;
5f3a4a28 256 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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257 posix_acl_release(acl);
258
259 return error;
260}
261
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262static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
263 const void *value, size_t size,
264 int flags, int type)
265{
266 char *full_name;
267
268 switch (type) {
269 case ACL_TYPE_ACCESS:
270 full_name = POSIX_ACL_XATTR_ACCESS;
271 break;
272 case ACL_TYPE_DEFAULT:
273 full_name = POSIX_ACL_XATTR_DEFAULT;
274 break;
275 default:
276 BUG();
277 }
278 return v9fs_xattr_set(dentry, full_name, value, size, flags);
279}
280
281
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282static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
283 const void *value, size_t size,
284 int flags, int type)
285{
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286 int retval;
287 struct posix_acl *acl;
76381a42 288 struct v9fs_session_info *v9ses;
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289 struct inode *inode = dentry->d_inode;
290
291 if (strcmp(name, "") != 0)
292 return -EINVAL;
76381a42 293
42869c8a 294 v9ses = v9fs_dentry2v9ses(dentry);
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295 /*
296 * set the attribute on the remote. Without even looking at the
297 * xattr value. We leave it to the server to validate
298 */
299 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
300 return v9fs_remote_set_acl(dentry, name,
301 value, size, flags, type);
302
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303 if (S_ISLNK(inode->i_mode))
304 return -EOPNOTSUPP;
2e149670 305 if (!inode_owner_or_capable(inode))
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306 return -EPERM;
307 if (value) {
308 /* update the cached acl value */
5f3a4a28 309 acl = posix_acl_from_xattr(&init_user_ns, value, size);
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310 if (IS_ERR(acl))
311 return PTR_ERR(acl);
312 else if (acl) {
313 retval = posix_acl_valid(acl);
314 if (retval)
315 goto err_out;
316 }
317 } else
318 acl = NULL;
319
320 switch (type) {
321 case ACL_TYPE_ACCESS:
322 name = POSIX_ACL_XATTR_ACCESS;
323 if (acl) {
d6952123 324 umode_t mode = inode->i_mode;
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325 retval = posix_acl_equiv_mode(acl, &mode);
326 if (retval < 0)
327 goto err_out;
328 else {
329 struct iattr iattr;
330 if (retval == 0) {
331 /*
332 * ACL can be represented
333 * by the mode bits. So don't
334 * update ACL.
335 */
336 acl = NULL;
337 value = NULL;
338 size = 0;
339 }
340 /* Updte the mode bits */
341 iattr.ia_mode = ((mode & S_IALLUGO) |
342 (inode->i_mode & ~S_IALLUGO));
343 iattr.ia_valid = ATTR_MODE;
344 /* FIXME should we update ctime ?
345 * What is the following setxattr update the
346 * mode ?
347 */
348 v9fs_vfs_setattr_dotl(dentry, &iattr);
349 }
350 }
351 break;
352 case ACL_TYPE_DEFAULT:
353 name = POSIX_ACL_XATTR_DEFAULT;
354 if (!S_ISDIR(inode->i_mode)) {
6f81c115 355 retval = acl ? -EINVAL : 0;
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356 goto err_out;
357 }
358 break;
359 default:
360 BUG();
361 }
362 retval = v9fs_xattr_set(dentry, name, value, size, flags);
363 if (!retval)
364 set_cached_acl(inode, type, acl);
365err_out:
366 posix_acl_release(acl);
367 return retval;
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368}
369
370const struct xattr_handler v9fs_xattr_acl_access_handler = {
371 .prefix = POSIX_ACL_XATTR_ACCESS,
372 .flags = ACL_TYPE_ACCESS,
373 .get = v9fs_xattr_get_acl,
374 .set = v9fs_xattr_set_acl,
375};
376
377const struct xattr_handler v9fs_xattr_acl_default_handler = {
378 .prefix = POSIX_ACL_XATTR_DEFAULT,
379 .flags = ACL_TYPE_DEFAULT,
380 .get = v9fs_xattr_get_acl,
381 .set = v9fs_xattr_set_acl,
382};