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9p: split dropping the acls from v9fs_set_create_acl()
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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,
5fa6300a 170 struct posix_acl *dacl, struct posix_acl *acl)
ad77dbce 171{
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AV
172 struct p9_fid *fid = v9fs_fid_lookup(dentry);
173 set_cached_acl(dentry->d_inode, ACL_TYPE_DEFAULT, dacl);
174 set_cached_acl(dentry->d_inode, ACL_TYPE_ACCESS, acl);
175 if (!IS_ERR(fid)) {
176 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl);
177 v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
1ec95bf3 178 }
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179 return 0;
180}
181
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182void v9fs_put_acl(struct posix_acl *dacl,
183 struct posix_acl *acl)
184{
185 posix_acl_release(dacl);
186 posix_acl_release(acl);
187}
188
d3fb6120 189int v9fs_acl_mode(struct inode *dir, umode_t *modep,
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190 struct posix_acl **dpacl, struct posix_acl **pacl)
191{
192 int retval = 0;
d3fb6120 193 umode_t mode = *modep;
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194 struct posix_acl *acl = NULL;
195
196 if (!S_ISLNK(mode)) {
197 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
198 if (IS_ERR(acl))
199 return PTR_ERR(acl);
200 if (!acl)
201 mode &= ~current_umask();
202 }
203 if (acl) {
ad77dbce 204 if (S_ISDIR(mode))
1ec95bf3 205 *dpacl = posix_acl_dup(acl);
826cae2f
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206 retval = posix_acl_create(&acl, GFP_NOFS, &mode);
207 if (retval < 0)
208 return retval;
ad77dbce 209 if (retval > 0)
826cae2f 210 *pacl = acl;
1ec95bf3 211 else
826cae2f 212 posix_acl_release(acl);
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213 }
214 *modep = mode;
215 return 0;
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216}
217
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218static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
219 void *buffer, size_t size, int type)
220{
221 char *full_name;
222
223 switch (type) {
224 case ACL_TYPE_ACCESS:
225 full_name = POSIX_ACL_XATTR_ACCESS;
226 break;
227 case ACL_TYPE_DEFAULT:
228 full_name = POSIX_ACL_XATTR_DEFAULT;
229 break;
230 default:
231 BUG();
232 }
233 return v9fs_xattr_get(dentry, full_name, buffer, size);
234}
235
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236static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
237 void *buffer, size_t size, int type)
238{
76381a42 239 struct v9fs_session_info *v9ses;
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240 struct posix_acl *acl;
241 int error;
242
243 if (strcmp(name, "") != 0)
244 return -EINVAL;
245
42869c8a 246 v9ses = v9fs_dentry2v9ses(dentry);
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247 /*
248 * We allow set/get/list of acl when access=client is not specified
249 */
250 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
251 return v9fs_remote_get_acl(dentry, name, buffer, size, type);
252
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253 acl = v9fs_get_cached_acl(dentry->d_inode, type);
254 if (IS_ERR(acl))
255 return PTR_ERR(acl);
256 if (acl == NULL)
257 return -ENODATA;
5f3a4a28 258 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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259 posix_acl_release(acl);
260
261 return error;
262}
263
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264static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
265 const void *value, size_t size,
266 int flags, int type)
267{
268 char *full_name;
269
270 switch (type) {
271 case ACL_TYPE_ACCESS:
272 full_name = POSIX_ACL_XATTR_ACCESS;
273 break;
274 case ACL_TYPE_DEFAULT:
275 full_name = POSIX_ACL_XATTR_DEFAULT;
276 break;
277 default:
278 BUG();
279 }
280 return v9fs_xattr_set(dentry, full_name, value, size, flags);
281}
282
283
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284static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
285 const void *value, size_t size,
286 int flags, int type)
287{
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288 int retval;
289 struct posix_acl *acl;
76381a42 290 struct v9fs_session_info *v9ses;
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291 struct inode *inode = dentry->d_inode;
292
293 if (strcmp(name, "") != 0)
294 return -EINVAL;
76381a42 295
42869c8a 296 v9ses = v9fs_dentry2v9ses(dentry);
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297 /*
298 * set the attribute on the remote. Without even looking at the
299 * xattr value. We leave it to the server to validate
300 */
301 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
302 return v9fs_remote_set_acl(dentry, name,
303 value, size, flags, type);
304
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305 if (S_ISLNK(inode->i_mode))
306 return -EOPNOTSUPP;
2e149670 307 if (!inode_owner_or_capable(inode))
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308 return -EPERM;
309 if (value) {
310 /* update the cached acl value */
5f3a4a28 311 acl = posix_acl_from_xattr(&init_user_ns, value, size);
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312 if (IS_ERR(acl))
313 return PTR_ERR(acl);
314 else if (acl) {
315 retval = posix_acl_valid(acl);
316 if (retval)
317 goto err_out;
318 }
319 } else
320 acl = NULL;
321
322 switch (type) {
323 case ACL_TYPE_ACCESS:
324 name = POSIX_ACL_XATTR_ACCESS;
325 if (acl) {
d6952123 326 umode_t mode = inode->i_mode;
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327 retval = posix_acl_equiv_mode(acl, &mode);
328 if (retval < 0)
329 goto err_out;
330 else {
331 struct iattr iattr;
332 if (retval == 0) {
333 /*
334 * ACL can be represented
335 * by the mode bits. So don't
336 * update ACL.
337 */
338 acl = NULL;
339 value = NULL;
340 size = 0;
341 }
342 /* Updte the mode bits */
343 iattr.ia_mode = ((mode & S_IALLUGO) |
344 (inode->i_mode & ~S_IALLUGO));
345 iattr.ia_valid = ATTR_MODE;
346 /* FIXME should we update ctime ?
347 * What is the following setxattr update the
348 * mode ?
349 */
350 v9fs_vfs_setattr_dotl(dentry, &iattr);
351 }
352 }
353 break;
354 case ACL_TYPE_DEFAULT:
355 name = POSIX_ACL_XATTR_DEFAULT;
356 if (!S_ISDIR(inode->i_mode)) {
6f81c115 357 retval = acl ? -EINVAL : 0;
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358 goto err_out;
359 }
360 break;
361 default:
362 BUG();
363 }
364 retval = v9fs_xattr_set(dentry, name, value, size, flags);
365 if (!retval)
366 set_cached_acl(inode, type, acl);
367err_out:
368 posix_acl_release(acl);
369 return retval;
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370}
371
372const struct xattr_handler v9fs_xattr_acl_access_handler = {
373 .prefix = POSIX_ACL_XATTR_ACCESS,
374 .flags = ACL_TYPE_ACCESS,
375 .get = v9fs_xattr_get_acl,
376 .set = v9fs_xattr_set_acl,
377};
378
379const struct xattr_handler v9fs_xattr_acl_default_handler = {
380 .prefix = POSIX_ACL_XATTR_DEFAULT,
381 .flags = ACL_TYPE_DEFAULT,
382 .get = v9fs_xattr_get_acl,
383 .set = v9fs_xattr_set_acl,
384};