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/xattr.h>
26 #include <linux/posix_acl_xattr.h>
31 * - all ACL updates are protected by inode->i_mutex, which is taken before
32 * calling into this file.
35 STATIC struct posix_acl *
36 xfs_acl_from_disk(struct xfs_acl *aclp)
38 struct posix_acl_entry *acl_e;
39 struct posix_acl *acl;
40 struct xfs_acl_entry *ace;
43 count = be32_to_cpu(aclp->acl_cnt);
45 acl = posix_acl_alloc(count, GFP_KERNEL);
47 return ERR_PTR(-ENOMEM);
49 for (i = 0; i < count; i++) {
50 acl_e = &acl->a_entries[i];
51 ace = &aclp->acl_entry[i];
54 * The tag is 32 bits on disk and 16 bits in core.
56 * Because every access to it goes through the core
57 * format first this is not a problem.
59 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
60 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
62 switch (acl_e->e_tag) {
65 acl_e->e_id = be32_to_cpu(ace->ae_id);
71 acl_e->e_id = ACL_UNDEFINED_ID;
80 posix_acl_release(acl);
81 return ERR_PTR(-EINVAL);
85 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
87 const struct posix_acl_entry *acl_e;
88 struct xfs_acl_entry *ace;
91 aclp->acl_cnt = cpu_to_be32(acl->a_count);
92 for (i = 0; i < acl->a_count; i++) {
93 ace = &aclp->acl_entry[i];
94 acl_e = &acl->a_entries[i];
96 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
97 ace->ae_id = cpu_to_be32(acl_e->e_id);
98 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
103 xfs_get_acl(struct inode *inode, int type)
105 struct xfs_inode *ip = XFS_I(inode);
106 struct posix_acl *acl;
107 struct xfs_acl *xfs_acl;
108 int len = sizeof(struct xfs_acl);
109 unsigned char *ea_name;
112 acl = get_cached_acl(inode, type);
113 if (acl != ACL_NOT_CACHED)
117 case ACL_TYPE_ACCESS:
118 ea_name = SGI_ACL_FILE;
120 case ACL_TYPE_DEFAULT:
121 ea_name = SGI_ACL_DEFAULT;
128 * If we have a cached ACLs value just return it, not need to
129 * go out to the disk.
132 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
134 return ERR_PTR(-ENOMEM);
136 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
140 * If the attribute doesn't exist make sure we have a negative
141 * cache entry, for any other error assume it is transient and
142 * leave the cache entry as ACL_NOT_CACHED.
144 if (error == -ENOATTR) {
146 goto out_update_cache;
151 acl = xfs_acl_from_disk(xfs_acl);
156 set_cached_acl(inode, type, acl);
163 xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
165 struct xfs_inode *ip = XFS_I(inode);
166 unsigned char *ea_name;
169 if (S_ISLNK(inode->i_mode))
173 case ACL_TYPE_ACCESS:
174 ea_name = SGI_ACL_FILE;
176 case ACL_TYPE_DEFAULT:
177 if (!S_ISDIR(inode->i_mode))
178 return acl ? -EACCES : 0;
179 ea_name = SGI_ACL_DEFAULT;
186 struct xfs_acl *xfs_acl;
189 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
193 xfs_acl_to_disk(xfs_acl, acl);
194 len = sizeof(struct xfs_acl) -
195 (sizeof(struct xfs_acl_entry) *
196 (XFS_ACL_MAX_ENTRIES - acl->a_count));
198 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
204 * A NULL ACL argument means we want to remove the ACL.
206 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
209 * If the attribute didn't exist to start with that's fine.
211 if (error == -ENOATTR)
216 set_cached_acl(inode, type, acl);
221 xfs_check_acl(struct inode *inode, int mask)
223 struct xfs_inode *ip = XFS_I(inode);
224 struct posix_acl *acl;
227 xfs_itrace_entry(ip);
230 * If there is no attribute fork no ACL exists on this inode and
231 * we can skip the whole exercise.
233 if (!XFS_IFORK_Q(ip))
236 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
240 error = posix_acl_permission(inode, acl, mask);
241 posix_acl_release(acl);
248 xfs_set_mode(struct inode *inode, mode_t mode)
252 if (mode != inode->i_mode) {
255 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
256 iattr.ia_mode = mode;
257 iattr.ia_ctime = current_fs_time(inode->i_sb);
259 error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
266 xfs_acl_exists(struct inode *inode, unsigned char *name)
268 int len = sizeof(struct xfs_acl);
270 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
271 ATTR_ROOT|ATTR_KERNOVAL) == 0);
275 posix_acl_access_exists(struct inode *inode)
277 return xfs_acl_exists(inode, SGI_ACL_FILE);
281 posix_acl_default_exists(struct inode *inode)
283 if (!S_ISDIR(inode->i_mode))
285 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
289 * No need for i_mutex because the inode is not yet exposed to the VFS.
292 xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl)
294 struct posix_acl *clone;
296 int error = 0, inherit = 0;
298 if (S_ISDIR(inode->i_mode)) {
299 error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl);
304 clone = posix_acl_clone(default_acl, GFP_KERNEL);
308 mode = inode->i_mode;
309 error = posix_acl_create_masq(clone, &mode);
311 goto out_release_clone;
314 * If posix_acl_create_masq returns a positive value we need to
315 * inherit a permission that can't be represented using the Unix
316 * mode bits and we actually need to set an ACL.
321 error = xfs_set_mode(inode, mode);
323 goto out_release_clone;
326 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
329 posix_acl_release(clone);
334 xfs_acl_chmod(struct inode *inode)
336 struct posix_acl *acl, *clone;
339 if (S_ISLNK(inode->i_mode))
342 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
343 if (IS_ERR(acl) || !acl)
346 clone = posix_acl_clone(acl, GFP_KERNEL);
347 posix_acl_release(acl);
351 error = posix_acl_chmod_masq(clone, inode->i_mode);
353 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
355 posix_acl_release(clone);
360 xfs_xattr_acl_get(struct dentry *dentry, const char *name,
361 void *value, size_t size, int type)
363 struct posix_acl *acl;
366 acl = xfs_get_acl(dentry->d_inode, type);
372 error = posix_acl_to_xattr(acl, value, size);
373 posix_acl_release(acl);
379 xfs_xattr_acl_set(struct dentry *dentry, const char *name,
380 const void *value, size_t size, int flags, int type)
382 struct inode *inode = dentry->d_inode;
383 struct posix_acl *acl = NULL;
386 if (flags & XATTR_CREATE)
388 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
389 return value ? -EACCES : 0;
390 if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
396 acl = posix_acl_from_xattr(value, size);
399 * acl_set_file(3) may request that we set default ACLs with
400 * zero length -- defend (gracefully) against that here.
405 error = PTR_ERR(acl);
409 error = posix_acl_valid(acl);
414 if (acl->a_count > XFS_ACL_MAX_ENTRIES)
417 if (type == ACL_TYPE_ACCESS) {
418 mode_t mode = inode->i_mode;
419 error = posix_acl_equiv_mode(acl, &mode);
422 posix_acl_release(acl);
429 error = xfs_set_mode(inode, mode);
435 error = xfs_set_acl(inode, type, acl);
437 posix_acl_release(acl);
442 struct xattr_handler xfs_xattr_acl_access_handler = {
443 .prefix = POSIX_ACL_XATTR_ACCESS,
444 .flags = ACL_TYPE_ACCESS,
445 .get = xfs_xattr_acl_get,
446 .set = xfs_xattr_acl_set,
449 struct xattr_handler xfs_xattr_acl_default_handler = {
450 .prefix = POSIX_ACL_XATTR_DEFAULT,
451 .flags = ACL_TYPE_DEFAULT,
452 .get = xfs_xattr_acl_get,
453 .set = xfs_xattr_acl_set,