2 * Copyright (c) 2008, Christoph Hellwig
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "xfs_bmap_btree.h"
22 #include "xfs_inode.h"
23 #include "xfs_vnodeops.h"
24 #include "xfs_trace.h"
25 #include <linux/slab.h>
26 #include <linux/xattr.h>
27 #include <linux/posix_acl_xattr.h>
32 * - all ACL updates are protected by inode->i_mutex, which is taken before
33 * calling into this file.
36 STATIC struct posix_acl *
37 xfs_acl_from_disk(struct xfs_acl *aclp)
39 struct posix_acl_entry *acl_e;
40 struct posix_acl *acl;
41 struct xfs_acl_entry *ace;
44 count = be32_to_cpu(aclp->acl_cnt);
45 if (count > XFS_ACL_MAX_ENTRIES)
46 return ERR_PTR(-EFSCORRUPTED);
48 acl = posix_acl_alloc(count, GFP_KERNEL);
50 return ERR_PTR(-ENOMEM);
52 for (i = 0; i < count; i++) {
53 acl_e = &acl->a_entries[i];
54 ace = &aclp->acl_entry[i];
57 * The tag is 32 bits on disk and 16 bits in core.
59 * Because every access to it goes through the core
60 * format first this is not a problem.
62 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
63 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
65 switch (acl_e->e_tag) {
68 acl_e->e_id = be32_to_cpu(ace->ae_id);
74 acl_e->e_id = ACL_UNDEFINED_ID;
83 posix_acl_release(acl);
84 return ERR_PTR(-EINVAL);
88 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
90 const struct posix_acl_entry *acl_e;
91 struct xfs_acl_entry *ace;
94 aclp->acl_cnt = cpu_to_be32(acl->a_count);
95 for (i = 0; i < acl->a_count; i++) {
96 ace = &aclp->acl_entry[i];
97 acl_e = &acl->a_entries[i];
99 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
100 ace->ae_id = cpu_to_be32(acl_e->e_id);
101 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
106 xfs_get_acl(struct inode *inode, int type)
108 struct xfs_inode *ip = XFS_I(inode);
109 struct posix_acl *acl;
110 struct xfs_acl *xfs_acl;
111 int len = sizeof(struct xfs_acl);
112 unsigned char *ea_name;
115 acl = get_cached_acl(inode, type);
116 if (acl != ACL_NOT_CACHED)
120 case ACL_TYPE_ACCESS:
121 ea_name = SGI_ACL_FILE;
123 case ACL_TYPE_DEFAULT:
124 ea_name = SGI_ACL_DEFAULT;
131 * If we have a cached ACLs value just return it, not need to
132 * go out to the disk.
135 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
137 return ERR_PTR(-ENOMEM);
139 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
143 * If the attribute doesn't exist make sure we have a negative
144 * cache entry, for any other error assume it is transient and
145 * leave the cache entry as ACL_NOT_CACHED.
147 if (error == -ENOATTR) {
149 goto out_update_cache;
154 acl = xfs_acl_from_disk(xfs_acl);
159 set_cached_acl(inode, type, acl);
166 xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
168 struct xfs_inode *ip = XFS_I(inode);
169 unsigned char *ea_name;
172 if (S_ISLNK(inode->i_mode))
176 case ACL_TYPE_ACCESS:
177 ea_name = SGI_ACL_FILE;
179 case ACL_TYPE_DEFAULT:
180 if (!S_ISDIR(inode->i_mode))
181 return acl ? -EACCES : 0;
182 ea_name = SGI_ACL_DEFAULT;
189 struct xfs_acl *xfs_acl;
192 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
196 xfs_acl_to_disk(xfs_acl, acl);
197 len = sizeof(struct xfs_acl) -
198 (sizeof(struct xfs_acl_entry) *
199 (XFS_ACL_MAX_ENTRIES - acl->a_count));
201 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
207 * A NULL ACL argument means we want to remove the ACL.
209 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
212 * If the attribute didn't exist to start with that's fine.
214 if (error == -ENOATTR)
219 set_cached_acl(inode, type, acl);
224 xfs_check_acl(struct inode *inode, int mask, unsigned int flags)
226 struct xfs_inode *ip;
227 struct posix_acl *acl;
231 trace_xfs_check_acl(ip);
234 * If there is no attribute fork no ACL exists on this inode and
235 * we can skip the whole exercise.
237 if (!XFS_IFORK_Q(ip))
240 if (flags & IPERM_FLAG_RCU) {
241 if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
246 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
250 error = posix_acl_permission(inode, acl, mask);
251 posix_acl_release(acl);
258 xfs_set_mode(struct inode *inode, mode_t mode)
262 if (mode != inode->i_mode) {
265 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
266 iattr.ia_mode = mode;
267 iattr.ia_ctime = current_fs_time(inode->i_sb);
269 error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
276 xfs_acl_exists(struct inode *inode, unsigned char *name)
278 int len = sizeof(struct xfs_acl);
280 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
281 ATTR_ROOT|ATTR_KERNOVAL) == 0);
285 posix_acl_access_exists(struct inode *inode)
287 return xfs_acl_exists(inode, SGI_ACL_FILE);
291 posix_acl_default_exists(struct inode *inode)
293 if (!S_ISDIR(inode->i_mode))
295 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
299 * No need for i_mutex because the inode is not yet exposed to the VFS.
302 xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl)
304 struct posix_acl *clone;
306 int error = 0, inherit = 0;
308 if (S_ISDIR(inode->i_mode)) {
309 error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl);
314 clone = posix_acl_clone(default_acl, GFP_KERNEL);
318 mode = inode->i_mode;
319 error = posix_acl_create_masq(clone, &mode);
321 goto out_release_clone;
324 * If posix_acl_create_masq returns a positive value we need to
325 * inherit a permission that can't be represented using the Unix
326 * mode bits and we actually need to set an ACL.
331 error = xfs_set_mode(inode, mode);
333 goto out_release_clone;
336 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
339 posix_acl_release(clone);
344 xfs_acl_chmod(struct inode *inode)
346 struct posix_acl *acl, *clone;
349 if (S_ISLNK(inode->i_mode))
352 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
353 if (IS_ERR(acl) || !acl)
356 clone = posix_acl_clone(acl, GFP_KERNEL);
357 posix_acl_release(acl);
361 error = posix_acl_chmod_masq(clone, inode->i_mode);
363 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
365 posix_acl_release(clone);
370 xfs_xattr_acl_get(struct dentry *dentry, const char *name,
371 void *value, size_t size, int type)
373 struct posix_acl *acl;
376 acl = xfs_get_acl(dentry->d_inode, type);
382 error = posix_acl_to_xattr(acl, value, size);
383 posix_acl_release(acl);
389 xfs_xattr_acl_set(struct dentry *dentry, const char *name,
390 const void *value, size_t size, int flags, int type)
392 struct inode *inode = dentry->d_inode;
393 struct posix_acl *acl = NULL;
396 if (flags & XATTR_CREATE)
398 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
399 return value ? -EACCES : 0;
400 if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
406 acl = posix_acl_from_xattr(value, size);
409 * acl_set_file(3) may request that we set default ACLs with
410 * zero length -- defend (gracefully) against that here.
415 error = PTR_ERR(acl);
419 error = posix_acl_valid(acl);
424 if (acl->a_count > XFS_ACL_MAX_ENTRIES)
427 if (type == ACL_TYPE_ACCESS) {
428 mode_t mode = inode->i_mode;
429 error = posix_acl_equiv_mode(acl, &mode);
432 posix_acl_release(acl);
439 error = xfs_set_mode(inode, mode);
445 error = xfs_set_acl(inode, type, acl);
447 posix_acl_release(acl);
452 const struct xattr_handler xfs_xattr_acl_access_handler = {
453 .prefix = POSIX_ACL_XATTR_ACCESS,
454 .flags = ACL_TYPE_ACCESS,
455 .get = xfs_xattr_acl_get,
456 .set = xfs_xattr_acl_set,
459 const struct xattr_handler xfs_xattr_acl_default_handler = {
460 .prefix = POSIX_ACL_XATTR_DEFAULT,
461 .flags = ACL_TYPE_DEFAULT,
462 .get = xfs_xattr_acl_get,
463 .set = xfs_xattr_acl_set,