2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright © 2006 NEC Corporation
6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
8 * For licensing information, see the file 'LICENCE' in this directory.
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
15 #include <linux/sched.h>
16 #include <linux/time.h>
17 #include <linux/crc32.h>
18 #include <linux/jffs2.h>
19 #include <linux/xattr.h>
20 #include <linux/posix_acl_xattr.h>
21 #include <linux/mtd/mtd.h>
24 static size_t jffs2_acl_size(int count)
27 return sizeof(struct jffs2_acl_header)
28 + count * sizeof(struct jffs2_acl_entry_short);
30 return sizeof(struct jffs2_acl_header)
31 + 4 * sizeof(struct jffs2_acl_entry_short)
32 + (count - 4) * sizeof(struct jffs2_acl_entry);
36 static int jffs2_acl_count(size_t size)
40 size -= sizeof(struct jffs2_acl_header);
41 if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
42 if (size % sizeof(struct jffs2_acl_entry_short))
44 return size / sizeof(struct jffs2_acl_entry_short);
46 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
47 if (s % sizeof(struct jffs2_acl_entry))
49 return s / sizeof(struct jffs2_acl_entry) + 4;
53 static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
55 void *end = value + size;
56 struct jffs2_acl_header *header = value;
57 struct jffs2_acl_entry *entry;
58 struct posix_acl *acl;
64 if (size < sizeof(struct jffs2_acl_header))
65 return ERR_PTR(-EINVAL);
66 ver = je32_to_cpu(header->a_version);
67 if (ver != JFFS2_ACL_VERSION) {
68 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
69 return ERR_PTR(-EINVAL);
72 value += sizeof(struct jffs2_acl_header);
73 count = jffs2_acl_count(size);
75 return ERR_PTR(-EINVAL);
79 acl = posix_acl_alloc(count, GFP_KERNEL);
81 return ERR_PTR(-ENOMEM);
83 for (i=0; i < count; i++) {
85 if (value + sizeof(struct jffs2_acl_entry_short) > end)
87 acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
88 acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
89 switch (acl->a_entries[i].e_tag) {
94 value += sizeof(struct jffs2_acl_entry_short);
95 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
100 value += sizeof(struct jffs2_acl_entry);
103 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
114 posix_acl_release(acl);
115 return ERR_PTR(-EINVAL);
118 static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
120 struct jffs2_acl_header *header;
121 struct jffs2_acl_entry *entry;
125 *size = jffs2_acl_size(acl->a_count);
126 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
128 return ERR_PTR(-ENOMEM);
129 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
131 for (i=0; i < acl->a_count; i++) {
133 entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
134 entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
135 switch(acl->a_entries[i].e_tag) {
138 entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
139 e += sizeof(struct jffs2_acl_entry);
146 e += sizeof(struct jffs2_acl_entry_short);
156 return ERR_PTR(-EINVAL);
159 static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
161 struct posix_acl *acl = ACL_NOT_CACHED;
163 spin_lock(&inode->i_lock);
164 if (*i_acl != ACL_NOT_CACHED)
165 acl = posix_acl_dup(*i_acl);
166 spin_unlock(&inode->i_lock);
170 static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
172 spin_lock(&inode->i_lock);
173 if (*i_acl != ACL_NOT_CACHED)
174 posix_acl_release(*i_acl);
175 *i_acl = posix_acl_dup(acl);
176 spin_unlock(&inode->i_lock);
179 static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
181 struct posix_acl *acl;
186 case ACL_TYPE_ACCESS:
187 acl = jffs2_iget_acl(inode, &inode->i_acl);
188 if (acl != ACL_NOT_CACHED)
190 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
192 case ACL_TYPE_DEFAULT:
193 acl = jffs2_iget_acl(inode, &inode->i_default_acl);
194 if (acl != ACL_NOT_CACHED)
196 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
199 return ERR_PTR(-EINVAL);
201 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
203 value = kmalloc(rc, GFP_KERNEL);
205 return ERR_PTR(-ENOMEM);
206 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
209 acl = jffs2_acl_from_medium(value, rc);
210 } else if (rc == -ENODATA || rc == -ENOSYS) {
219 case ACL_TYPE_ACCESS:
220 jffs2_iset_acl(inode, &inode->i_acl, acl);
222 case ACL_TYPE_DEFAULT:
223 jffs2_iset_acl(inode, &inode->i_default_acl, acl);
230 static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
237 value = jffs2_acl_to_medium(acl, &size);
239 return PTR_ERR(value);
241 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
242 if (!value && rc == -ENODATA)
249 static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
253 if (S_ISLNK(inode->i_mode))
257 case ACL_TYPE_ACCESS:
258 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
260 mode_t mode = inode->i_mode;
261 rc = posix_acl_equiv_mode(acl, &mode);
264 if (inode->i_mode != mode) {
267 attr.ia_valid = ATTR_MODE;
269 rc = jffs2_do_setattr(inode, &attr);
277 case ACL_TYPE_DEFAULT:
278 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
279 if (!S_ISDIR(inode->i_mode))
280 return acl ? -EACCES : 0;
285 rc = __jffs2_set_acl(inode, xprefix, acl);
288 case ACL_TYPE_ACCESS:
289 jffs2_iset_acl(inode, &inode->i_acl, acl);
291 case ACL_TYPE_DEFAULT:
292 jffs2_iset_acl(inode, &inode->i_default_acl, acl);
299 static int jffs2_check_acl(struct inode *inode, int mask)
301 struct posix_acl *acl;
304 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
308 rc = posix_acl_permission(inode, acl, mask);
309 posix_acl_release(acl);
315 int jffs2_permission(struct inode *inode, int mask)
317 return generic_permission(inode, mask, jffs2_check_acl);
320 int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode)
322 struct posix_acl *acl, *clone;
325 inode->i_default_acl = NULL;
328 if (S_ISLNK(*i_mode))
329 return 0; /* Symlink always has no-ACL */
331 acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
336 *i_mode &= ~current_umask();
338 if (S_ISDIR(*i_mode))
339 jffs2_iset_acl(inode, &inode->i_default_acl, acl);
341 clone = posix_acl_clone(acl, GFP_KERNEL);
344 rc = posix_acl_create_masq(clone, (mode_t *)i_mode);
346 posix_acl_release(clone);
350 jffs2_iset_acl(inode, &inode->i_acl, clone);
352 posix_acl_release(clone);
357 int jffs2_init_acl_post(struct inode *inode)
361 if (inode->i_default_acl) {
362 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
368 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
376 int jffs2_acl_chmod(struct inode *inode)
378 struct posix_acl *acl, *clone;
381 if (S_ISLNK(inode->i_mode))
383 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
384 if (IS_ERR(acl) || !acl)
386 clone = posix_acl_clone(acl, GFP_KERNEL);
387 posix_acl_release(acl);
390 rc = posix_acl_chmod_masq(clone, inode->i_mode);
392 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
393 posix_acl_release(clone);
397 static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
398 const char *name, size_t name_len)
400 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
402 if (list && retlen <= list_size)
403 strcpy(list, POSIX_ACL_XATTR_ACCESS);
407 static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
408 const char *name, size_t name_len)
410 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
412 if (list && retlen <= list_size)
413 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
417 static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
419 struct posix_acl *acl;
422 acl = jffs2_get_acl(inode, type);
427 rc = posix_acl_to_xattr(acl, buffer, size);
428 posix_acl_release(acl);
433 static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
437 return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
440 static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
444 return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
447 static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
449 struct posix_acl *acl;
452 if (!is_owner_or_cap(inode))
456 acl = posix_acl_from_xattr(value, size);
460 rc = posix_acl_valid(acl);
467 rc = jffs2_set_acl(inode, type, acl);
469 posix_acl_release(acl);
473 static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
474 const void *buffer, size_t size, int flags)
478 return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
481 static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
482 const void *buffer, size_t size, int flags)
486 return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
489 struct xattr_handler jffs2_acl_access_xattr_handler = {
490 .prefix = POSIX_ACL_XATTR_ACCESS,
491 .list = jffs2_acl_access_listxattr,
492 .get = jffs2_acl_access_getxattr,
493 .set = jffs2_acl_access_setxattr,
496 struct xattr_handler jffs2_acl_default_xattr_handler = {
497 .prefix = POSIX_ACL_XATTR_DEFAULT,
498 .list = jffs2_acl_default_listxattr,
499 .get = jffs2_acl_default_getxattr,
500 .set = jffs2_acl_default_setxattr,