2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright (C) 2006 NEC Corporation
6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
8 * For licensing information, see the file 'LICENCE' in this directory.
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
14 #include <linux/time.h>
15 #include <linux/crc32.h>
16 #include <linux/jffs2.h>
17 #include <linux/xattr.h>
18 #include <linux/posix_acl_xattr.h>
19 #include <linux/mtd/mtd.h>
22 static size_t jffs2_acl_size(int count)
25 return sizeof(struct jffs2_acl_header)
26 + count * sizeof(struct jffs2_acl_entry_short);
28 return sizeof(struct jffs2_acl_header)
29 + 4 * sizeof(struct jffs2_acl_entry_short)
30 + (count - 4) * sizeof(struct jffs2_acl_entry);
34 static int jffs2_acl_count(size_t size)
38 size -= sizeof(struct jffs2_acl_header);
39 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
41 if (size % sizeof(struct jffs2_acl_entry_short))
43 return size / sizeof(struct jffs2_acl_entry_short);
45 if (s % sizeof(struct jffs2_acl_entry))
47 return s / sizeof(struct jffs2_acl_entry) + 4;
51 static struct posix_acl *jffs2_acl_from_medium(const void *value, size_t size)
53 const char *end = (char *)value + size;
54 struct posix_acl *acl;
60 if (size < sizeof(struct jffs2_acl_header))
61 return ERR_PTR(-EINVAL);
62 ver = je32_to_cpu(((struct jffs2_acl_header *)value)->a_version);
63 if (ver != JFFS2_ACL_VERSION) {
64 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
65 return ERR_PTR(-EINVAL);
68 value = (char *)value + sizeof(struct jffs2_acl_header);
69 count = jffs2_acl_count(size);
71 return ERR_PTR(-EINVAL);
75 acl = posix_acl_alloc(count, GFP_KERNEL);
77 return ERR_PTR(-ENOMEM);
79 for (i=0; i < count; i++) {
80 struct jffs2_acl_entry *entry = (struct jffs2_acl_entry *)value;
81 if ((char *)value + sizeof(struct jffs2_acl_entry_short) > end)
83 acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
84 acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
85 switch (acl->a_entries[i].e_tag) {
90 value = (char *)value + sizeof(struct jffs2_acl_entry_short);
91 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
96 value = (char *)value + sizeof(struct jffs2_acl_entry);
97 if ((char *)value > end)
99 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
110 posix_acl_release(acl);
111 return ERR_PTR(-EINVAL);
114 static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
116 struct jffs2_acl_header *jffs2_acl;
120 *size = jffs2_acl_size(acl->a_count);
121 jffs2_acl = kmalloc(sizeof(struct jffs2_acl_header)
122 + acl->a_count * sizeof(struct jffs2_acl_entry),
125 return ERR_PTR(-ENOMEM);
126 jffs2_acl->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
127 e = (char *)jffs2_acl + sizeof(struct jffs2_acl_header);
128 for (i=0; i < acl->a_count; i++) {
129 struct jffs2_acl_entry *entry = (struct jffs2_acl_entry *)e;
130 entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
131 entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
132 switch(acl->a_entries[i].e_tag) {
135 entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
136 e += sizeof(struct jffs2_acl_entry);
143 e += sizeof(struct jffs2_acl_entry_short);
150 return (char *)jffs2_acl;
153 return ERR_PTR(-EINVAL);
156 static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
158 struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;
160 spin_lock(&inode->i_lock);
161 if (*i_acl != JFFS2_ACL_NOT_CACHED)
162 acl = posix_acl_dup(*i_acl);
163 spin_unlock(&inode->i_lock);
167 static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
169 spin_lock(&inode->i_lock);
170 if (*i_acl != JFFS2_ACL_NOT_CACHED)
171 posix_acl_release(*i_acl);
172 *i_acl = posix_acl_dup(acl);
173 spin_unlock(&inode->i_lock);
176 static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
178 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
179 struct posix_acl *acl;
184 case ACL_TYPE_ACCESS:
185 acl = jffs2_iget_acl(inode, &f->i_acl_access);
186 if (acl != JFFS2_ACL_NOT_CACHED)
188 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
190 case ACL_TYPE_DEFAULT:
191 acl = jffs2_iget_acl(inode, &f->i_acl_default);
192 if (acl != JFFS2_ACL_NOT_CACHED)
194 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
197 return ERR_PTR(-EINVAL);
199 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
201 value = kmalloc(rc, GFP_KERNEL);
203 return ERR_PTR(-ENOMEM);
204 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
207 acl = jffs2_acl_from_medium(value, rc);
208 } else if (rc == -ENODATA || rc == -ENOSYS) {
217 case ACL_TYPE_ACCESS:
218 jffs2_iset_acl(inode, &f->i_acl_access, acl);
220 case ACL_TYPE_DEFAULT:
221 jffs2_iset_acl(inode, &f->i_acl_default, acl);
228 static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
230 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
235 if (S_ISLNK(inode->i_mode))
239 case ACL_TYPE_ACCESS:
240 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
242 mode_t mode = inode->i_mode;
243 rc = posix_acl_equiv_mode(acl, &mode);
246 if (inode->i_mode != mode) {
247 inode->i_mode = mode;
248 jffs2_dirty_inode(inode);
254 case ACL_TYPE_DEFAULT:
255 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
256 if (!S_ISDIR(inode->i_mode))
257 return acl ? -EACCES : 0;
263 value = jffs2_acl_to_medium(acl, &size);
265 return PTR_ERR(value);
268 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
273 case ACL_TYPE_ACCESS:
274 jffs2_iset_acl(inode, &f->i_acl_access, acl);
276 case ACL_TYPE_DEFAULT:
277 jffs2_iset_acl(inode, &f->i_acl_default, acl);
284 static int jffs2_check_acl(struct inode *inode, int mask)
286 struct posix_acl *acl;
289 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
293 rc = posix_acl_permission(inode, acl, mask);
294 posix_acl_release(acl);
300 int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
302 return generic_permission(inode, mask, jffs2_check_acl);
305 int jffs2_init_acl(struct inode *inode, struct inode *dir)
307 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
308 struct posix_acl *acl = NULL, *clone;
312 f->i_acl_access = JFFS2_ACL_NOT_CACHED;
313 f->i_acl_default = JFFS2_ACL_NOT_CACHED;
314 if (!S_ISLNK(inode->i_mode)) {
315 acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
319 inode->i_mode &= ~current->fs->umask;
322 if (S_ISDIR(inode->i_mode)) {
323 rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
327 clone = posix_acl_clone(acl, GFP_KERNEL);
331 mode = inode->i_mode;
332 rc = posix_acl_create_masq(clone, &mode);
334 inode->i_mode = mode;
336 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
338 posix_acl_release(clone);
341 posix_acl_release(acl);
345 void jffs2_clear_acl(struct inode *inode)
347 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
349 if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
350 posix_acl_release(f->i_acl_access);
351 f->i_acl_access = JFFS2_ACL_NOT_CACHED;
353 if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
354 posix_acl_release(f->i_acl_default);
355 f->i_acl_default = JFFS2_ACL_NOT_CACHED;
359 int jffs2_acl_chmod(struct inode *inode)
361 struct posix_acl *acl, *clone;
364 if (S_ISLNK(inode->i_mode))
366 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
367 if (IS_ERR(acl) || !acl)
369 clone = posix_acl_clone(acl, GFP_KERNEL);
370 posix_acl_release(acl);
373 rc = posix_acl_chmod_masq(clone, inode->i_mode);
375 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
376 posix_acl_release(clone);
380 static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
381 const char *name, size_t name_len)
383 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
385 if (list && retlen <= list_size)
386 strcpy(list, POSIX_ACL_XATTR_ACCESS);
390 static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
391 const char *name, size_t name_len)
393 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
395 if (list && retlen <= list_size)
396 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
400 static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
402 struct posix_acl *acl;
405 acl = jffs2_get_acl(inode, type);
410 rc = posix_acl_to_xattr(acl, buffer, size);
411 posix_acl_release(acl);
416 static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
420 return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
423 static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
427 return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
430 static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
432 struct posix_acl *acl;
435 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
439 acl = posix_acl_from_xattr(value, size);
443 rc = posix_acl_valid(acl);
450 rc = jffs2_set_acl(inode, type, acl);
452 posix_acl_release(acl);
456 static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
457 const void *buffer, size_t size, int flags)
461 return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
464 static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
465 const void *buffer, size_t size, int flags)
469 return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
472 struct xattr_handler jffs2_acl_access_xattr_handler = {
473 .prefix = POSIX_ACL_XATTR_ACCESS,
474 .list = jffs2_acl_access_listxattr,
475 .get = jffs2_acl_access_getxattr,
476 .set = jffs2_acl_access_setxattr,
479 struct xattr_handler jffs2_acl_default_xattr_handler = {
480 .prefix = POSIX_ACL_XATTR_DEFAULT,
481 .list = jffs2_acl_default_listxattr,
482 .get = jffs2_acl_default_getxattr,
483 .set = jffs2_acl_default_setxattr,