usb: gadget: f_mtp: Avoid race between mtp_read and mtp_function_disable
[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / fs / f2fs / acl.c
CommitLineData
0a8165d7 1/*
af48b85b
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2 * fs/f2fs/acl.c
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * Portions of this code from linux/fs/ext2/acl.c
8 *
9 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15#include <linux/f2fs_fs.h>
16#include "f2fs.h"
17#include "xattr.h"
18#include "acl.h"
19
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20static inline size_t f2fs_acl_size(int count)
21{
22 if (count <= 4) {
23 return sizeof(struct f2fs_acl_header) +
24 count * sizeof(struct f2fs_acl_entry_short);
25 } else {
26 return sizeof(struct f2fs_acl_header) +
27 4 * sizeof(struct f2fs_acl_entry_short) +
28 (count - 4) * sizeof(struct f2fs_acl_entry);
29 }
30}
31
32static inline int f2fs_acl_count(size_t size)
33{
34 ssize_t s;
35 size -= sizeof(struct f2fs_acl_header);
36 s = size - 4 * sizeof(struct f2fs_acl_entry_short);
37 if (s < 0) {
38 if (size % sizeof(struct f2fs_acl_entry_short))
39 return -1;
40 return size / sizeof(struct f2fs_acl_entry_short);
41 } else {
42 if (s % sizeof(struct f2fs_acl_entry))
43 return -1;
44 return s / sizeof(struct f2fs_acl_entry) + 4;
45 }
46}
47
48static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
49{
50 int i, count;
51 struct posix_acl *acl;
52 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
53 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
54 const char *end = value + size;
55
56 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
57 return ERR_PTR(-EINVAL);
58
59 count = f2fs_acl_count(size);
60 if (count < 0)
61 return ERR_PTR(-EINVAL);
62 if (count == 0)
63 return NULL;
64
dd802406 65 acl = posix_acl_alloc(count, GFP_NOFS);
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66 if (!acl)
67 return ERR_PTR(-ENOMEM);
68
69 for (i = 0; i < count; i++) {
70
71 if ((char *)entry > end)
72 goto fail;
73
74 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
75 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
76
77 switch (acl->a_entries[i].e_tag) {
78 case ACL_USER_OBJ:
79 case ACL_GROUP_OBJ:
80 case ACL_MASK:
81 case ACL_OTHER:
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82 entry = (struct f2fs_acl_entry *)((char *)entry +
83 sizeof(struct f2fs_acl_entry_short));
84 break;
85
86 case ACL_USER:
87 acl->a_entries[i].e_uid =
88 make_kuid(&init_user_ns,
89 le32_to_cpu(entry->e_id));
90 entry = (struct f2fs_acl_entry *)((char *)entry +
91 sizeof(struct f2fs_acl_entry));
92 break;
93 case ACL_GROUP:
94 acl->a_entries[i].e_gid =
95 make_kgid(&init_user_ns,
96 le32_to_cpu(entry->e_id));
97 entry = (struct f2fs_acl_entry *)((char *)entry +
98 sizeof(struct f2fs_acl_entry));
99 break;
100 default:
101 goto fail;
102 }
103 }
104 if ((char *)entry != end)
105 goto fail;
106 return acl;
107fail:
108 posix_acl_release(acl);
109 return ERR_PTR(-EINVAL);
110}
111
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112static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi,
113 const struct posix_acl *acl, size_t *size)
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114{
115 struct f2fs_acl_header *f2fs_acl;
116 struct f2fs_acl_entry *entry;
117 int i;
118
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119 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) +
120 acl->a_count * sizeof(struct f2fs_acl_entry),
121 GFP_NOFS);
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122 if (!f2fs_acl)
123 return ERR_PTR(-ENOMEM);
124
125 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
126 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
127
128 for (i = 0; i < acl->a_count; i++) {
129
130 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
131 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
132
133 switch (acl->a_entries[i].e_tag) {
134 case ACL_USER:
135 entry->e_id = cpu_to_le32(
136 from_kuid(&init_user_ns,
137 acl->a_entries[i].e_uid));
138 entry = (struct f2fs_acl_entry *)((char *)entry +
139 sizeof(struct f2fs_acl_entry));
140 break;
141 case ACL_GROUP:
142 entry->e_id = cpu_to_le32(
143 from_kgid(&init_user_ns,
144 acl->a_entries[i].e_gid));
145 entry = (struct f2fs_acl_entry *)((char *)entry +
146 sizeof(struct f2fs_acl_entry));
147 break;
148 case ACL_USER_OBJ:
149 case ACL_GROUP_OBJ:
150 case ACL_MASK:
151 case ACL_OTHER:
152 entry = (struct f2fs_acl_entry *)((char *)entry +
153 sizeof(struct f2fs_acl_entry_short));
154 break;
155 default:
156 goto fail;
157 }
158 }
159 *size = f2fs_acl_size(acl->a_count);
160 return (void *)f2fs_acl;
161
162fail:
163 kfree(f2fs_acl);
164 return ERR_PTR(-EINVAL);
165}
166
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167static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
168 struct page *dpage)
af48b85b 169{
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170 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
171 void *value = NULL;
172 struct posix_acl *acl;
173 int retval;
174
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175 if (type == ACL_TYPE_ACCESS)
176 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
177
bce8d112 178 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
af48b85b 179 if (retval > 0) {
c1286ff4 180 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO);
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181 if (!value)
182 return ERR_PTR(-ENOMEM);
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183 retval = f2fs_getxattr(inode, name_index, "", value,
184 retval, dpage);
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185 }
186
c1b75eab 187 if (retval > 0)
af48b85b 188 acl = f2fs_acl_from_disk(value, retval);
c1b75eab
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189 else if (retval == -ENODATA)
190 acl = NULL;
191 else
192 acl = ERR_PTR(retval);
af48b85b 193 kfree(value);
c1b75eab 194
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195 if (!IS_ERR(acl))
196 set_cached_acl(inode, type, acl);
197
198 return acl;
199}
200
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201struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
202{
203 return __f2fs_get_acl(inode, type, NULL);
204}
205
a6dda0e6 206static int __f2fs_set_acl(struct inode *inode, int type,
2ed2d5b3 207 struct posix_acl *acl, struct page *ipage)
af48b85b 208{
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209 int name_index;
210 void *value = NULL;
211 size_t size = 0;
212 int error;
13f00235 213 umode_t mode = inode->i_mode;
af48b85b 214
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215 switch (type) {
216 case ACL_TYPE_ACCESS:
217 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
13f00235
JK
218 if (acl && !ipage) {
219 error = posix_acl_update_mode(inode, &mode, &acl);
91d38ba8 220 if (error)
af48b85b 221 return error;
13f00235 222 set_acl_inode(inode, mode);
af48b85b
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223 }
224 break;
225
226 case ACL_TYPE_DEFAULT:
227 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
228 if (!S_ISDIR(inode->i_mode))
229 return acl ? -EACCES : 0;
230 break;
231
232 default:
233 return -EINVAL;
234 }
235
236 if (acl) {
c1286ff4 237 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size);
af48b85b 238 if (IS_ERR(value)) {
c1286ff4 239 clear_inode_flag(inode, FI_ACL_MODE);
13f00235 240 return PTR_ERR(value);
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241 }
242 }
243
c02745ef 244 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
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245
246 kfree(value);
247 if (!error)
248 set_cached_acl(inode, type, acl);
249
c1286ff4 250 clear_inode_flag(inode, FI_ACL_MODE);
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251 return error;
252}
253
a6dda0e6 254int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
af48b85b 255{
353c1624
JK
256 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
257 return -EIO;
258
a6dda0e6 259 return __f2fs_set_acl(inode, type, acl, NULL);
af48b85b
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260}
261
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262/*
263 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
264 * are copied from posix_acl.c
265 */
266static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
267 gfp_t flags)
268{
269 struct posix_acl *clone = NULL;
270
271 if (acl) {
272 int size = sizeof(struct posix_acl) + acl->a_count *
273 sizeof(struct posix_acl_entry);
274 clone = kmemdup(acl, size, flags);
275 if (clone)
276 atomic_set(&clone->a_refcount, 1);
277 }
278 return clone;
279}
280
281static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
282{
283 struct posix_acl_entry *pa, *pe;
284 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
285 umode_t mode = *mode_p;
286 int not_equiv = 0;
287
288 /* assert(atomic_read(acl->a_refcount) == 1); */
289
290 FOREACH_ACL_ENTRY(pa, acl, pe) {
291 switch(pa->e_tag) {
292 case ACL_USER_OBJ:
293 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
294 mode &= (pa->e_perm << 6) | ~S_IRWXU;
295 break;
296
297 case ACL_USER:
298 case ACL_GROUP:
299 not_equiv = 1;
300 break;
301
302 case ACL_GROUP_OBJ:
303 group_obj = pa;
304 break;
305
306 case ACL_OTHER:
307 pa->e_perm &= mode | ~S_IRWXO;
308 mode &= pa->e_perm | ~S_IRWXO;
309 break;
310
311 case ACL_MASK:
312 mask_obj = pa;
313 not_equiv = 1;
314 break;
315
316 default:
317 return -EIO;
318 }
319 }
320
321 if (mask_obj) {
322 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
323 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
324 } else {
325 if (!group_obj)
326 return -EIO;
327 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
328 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
329 }
330
331 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
332 return not_equiv;
333}
334
335static int f2fs_acl_create(struct inode *dir, umode_t *mode,
336 struct posix_acl **default_acl, struct posix_acl **acl,
337 struct page *dpage)
338{
339 struct posix_acl *p;
272e083f 340 struct posix_acl *clone;
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341 int ret;
342
272e083f
CY
343 *acl = NULL;
344 *default_acl = NULL;
345
bce8d112 346 if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
272e083f 347 return 0;
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348
349 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
272e083f
CY
350 if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
351 *mode &= ~current_umask();
352 return 0;
bce8d112 353 }
272e083f
CY
354 if (IS_ERR(p))
355 return PTR_ERR(p);
bce8d112 356
272e083f
CY
357 clone = f2fs_acl_clone(p, GFP_NOFS);
358 if (!clone)
83dfe53c 359 goto no_mem;
bce8d112 360
272e083f 361 ret = f2fs_acl_create_masq(clone, mode);
83dfe53c
CY
362 if (ret < 0)
363 goto no_mem_clone;
bce8d112 364
272e083f
CY
365 if (ret == 0)
366 posix_acl_release(clone);
367 else
368 *acl = clone;
bce8d112 369
272e083f 370 if (!S_ISDIR(*mode))
bce8d112 371 posix_acl_release(p);
272e083f 372 else
bce8d112 373 *default_acl = p;
bce8d112 374
bce8d112 375 return 0;
83dfe53c
CY
376
377no_mem_clone:
272e083f 378 posix_acl_release(clone);
83dfe53c
CY
379no_mem:
380 posix_acl_release(p);
381 return -ENOMEM;
bce8d112
JK
382}
383
384int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
385 struct page *dpage)
af48b85b 386{
bce8d112 387 struct posix_acl *default_acl = NULL, *acl = NULL;
a6dda0e6 388 int error = 0;
af48b85b 389
bce8d112 390 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
af48b85b
JK
391 if (error)
392 return error;
b8b60e1a 393
0ef31c7b 394 f2fs_mark_inode_dirty_sync(inode, true);
c1286ff4 395
a6dda0e6
CH
396 if (default_acl) {
397 error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
398 ipage);
399 posix_acl_release(default_acl);
400 }
401 if (acl) {
3b6709b7 402 if (!error)
a6dda0e6
CH
403 error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
404 ipage);
405 posix_acl_release(acl);
af48b85b
JK
406 }
407
af48b85b
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408 return error;
409}