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
);
46 acl
= posix_acl_alloc(count
, GFP_KERNEL
);
48 return ERR_PTR(-ENOMEM
);
50 for (i
= 0; i
< count
; i
++) {
51 acl_e
= &acl
->a_entries
[i
];
52 ace
= &aclp
->acl_entry
[i
];
55 * The tag is 32 bits on disk and 16 bits in core.
57 * Because every access to it goes through the core
58 * format first this is not a problem.
60 acl_e
->e_tag
= be32_to_cpu(ace
->ae_tag
);
61 acl_e
->e_perm
= be16_to_cpu(ace
->ae_perm
);
63 switch (acl_e
->e_tag
) {
66 acl_e
->e_id
= be32_to_cpu(ace
->ae_id
);
72 acl_e
->e_id
= ACL_UNDEFINED_ID
;
81 posix_acl_release(acl
);
82 return ERR_PTR(-EINVAL
);
86 xfs_acl_to_disk(struct xfs_acl
*aclp
, const struct posix_acl
*acl
)
88 const struct posix_acl_entry
*acl_e
;
89 struct xfs_acl_entry
*ace
;
92 aclp
->acl_cnt
= cpu_to_be32(acl
->a_count
);
93 for (i
= 0; i
< acl
->a_count
; i
++) {
94 ace
= &aclp
->acl_entry
[i
];
95 acl_e
= &acl
->a_entries
[i
];
97 ace
->ae_tag
= cpu_to_be32(acl_e
->e_tag
);
98 ace
->ae_id
= cpu_to_be32(acl_e
->e_id
);
99 ace
->ae_perm
= cpu_to_be16(acl_e
->e_perm
);
104 xfs_get_acl(struct inode
*inode
, int type
)
106 struct xfs_inode
*ip
= XFS_I(inode
);
107 struct posix_acl
*acl
;
108 struct xfs_acl
*xfs_acl
;
109 int len
= sizeof(struct xfs_acl
);
110 unsigned char *ea_name
;
113 acl
= get_cached_acl(inode
, type
);
114 if (acl
!= ACL_NOT_CACHED
)
118 case ACL_TYPE_ACCESS
:
119 ea_name
= SGI_ACL_FILE
;
121 case ACL_TYPE_DEFAULT
:
122 ea_name
= SGI_ACL_DEFAULT
;
129 * If we have a cached ACLs value just return it, not need to
130 * go out to the disk.
133 xfs_acl
= kzalloc(sizeof(struct xfs_acl
), GFP_KERNEL
);
135 return ERR_PTR(-ENOMEM
);
137 error
= -xfs_attr_get(ip
, ea_name
, (unsigned char *)xfs_acl
,
141 * If the attribute doesn't exist make sure we have a negative
142 * cache entry, for any other error assume it is transient and
143 * leave the cache entry as ACL_NOT_CACHED.
145 if (error
== -ENOATTR
) {
147 goto out_update_cache
;
152 acl
= xfs_acl_from_disk(xfs_acl
);
157 set_cached_acl(inode
, type
, acl
);
164 xfs_set_acl(struct inode
*inode
, int type
, struct posix_acl
*acl
)
166 struct xfs_inode
*ip
= XFS_I(inode
);
167 unsigned char *ea_name
;
170 if (S_ISLNK(inode
->i_mode
))
174 case ACL_TYPE_ACCESS
:
175 ea_name
= SGI_ACL_FILE
;
177 case ACL_TYPE_DEFAULT
:
178 if (!S_ISDIR(inode
->i_mode
))
179 return acl
? -EACCES
: 0;
180 ea_name
= SGI_ACL_DEFAULT
;
187 struct xfs_acl
*xfs_acl
;
190 xfs_acl
= kzalloc(sizeof(struct xfs_acl
), GFP_KERNEL
);
194 xfs_acl_to_disk(xfs_acl
, acl
);
195 len
= sizeof(struct xfs_acl
) -
196 (sizeof(struct xfs_acl_entry
) *
197 (XFS_ACL_MAX_ENTRIES
- acl
->a_count
));
199 error
= -xfs_attr_set(ip
, ea_name
, (unsigned char *)xfs_acl
,
205 * A NULL ACL argument means we want to remove the ACL.
207 error
= -xfs_attr_remove(ip
, ea_name
, ATTR_ROOT
);
210 * If the attribute didn't exist to start with that's fine.
212 if (error
== -ENOATTR
)
217 set_cached_acl(inode
, type
, acl
);
222 xfs_check_acl(struct inode
*inode
, int mask
)
224 struct posix_acl
*acl
;
227 trace_xfs_check_acl(XFS_I(inode
));
229 acl
= xfs_get_acl(inode
, ACL_TYPE_ACCESS
);
233 error
= posix_acl_permission(inode
, acl
, mask
);
234 posix_acl_release(acl
);
241 xfs_set_mode(struct inode
*inode
, mode_t mode
)
245 if (mode
!= inode
->i_mode
) {
248 iattr
.ia_valid
= ATTR_MODE
| ATTR_CTIME
;
249 iattr
.ia_mode
= mode
;
250 iattr
.ia_ctime
= current_fs_time(inode
->i_sb
);
252 error
= -xfs_setattr_nonsize(XFS_I(inode
), &iattr
, XFS_ATTR_NOACL
);
259 xfs_acl_exists(struct inode
*inode
, unsigned char *name
)
261 int len
= sizeof(struct xfs_acl
);
263 return (xfs_attr_get(XFS_I(inode
), name
, NULL
, &len
,
264 ATTR_ROOT
|ATTR_KERNOVAL
) == 0);
268 posix_acl_access_exists(struct inode
*inode
)
270 return xfs_acl_exists(inode
, SGI_ACL_FILE
);
274 posix_acl_default_exists(struct inode
*inode
)
276 if (!S_ISDIR(inode
->i_mode
))
278 return xfs_acl_exists(inode
, SGI_ACL_DEFAULT
);
282 * No need for i_mutex because the inode is not yet exposed to the VFS.
285 xfs_inherit_acl(struct inode
*inode
, struct posix_acl
*default_acl
)
287 struct posix_acl
*clone
;
289 int error
= 0, inherit
= 0;
291 if (S_ISDIR(inode
->i_mode
)) {
292 error
= xfs_set_acl(inode
, ACL_TYPE_DEFAULT
, default_acl
);
297 clone
= posix_acl_clone(default_acl
, GFP_KERNEL
);
301 mode
= inode
->i_mode
;
302 error
= posix_acl_create_masq(clone
, &mode
);
304 goto out_release_clone
;
307 * If posix_acl_create_masq returns a positive value we need to
308 * inherit a permission that can't be represented using the Unix
309 * mode bits and we actually need to set an ACL.
314 error
= xfs_set_mode(inode
, mode
);
316 goto out_release_clone
;
319 error
= xfs_set_acl(inode
, ACL_TYPE_ACCESS
, clone
);
322 posix_acl_release(clone
);
327 xfs_acl_chmod(struct inode
*inode
)
329 struct posix_acl
*acl
, *clone
;
332 if (S_ISLNK(inode
->i_mode
))
335 acl
= xfs_get_acl(inode
, ACL_TYPE_ACCESS
);
336 if (IS_ERR(acl
) || !acl
)
339 clone
= posix_acl_clone(acl
, GFP_KERNEL
);
340 posix_acl_release(acl
);
344 error
= posix_acl_chmod_masq(clone
, inode
->i_mode
);
346 error
= xfs_set_acl(inode
, ACL_TYPE_ACCESS
, clone
);
348 posix_acl_release(clone
);
353 xfs_xattr_acl_get(struct dentry
*dentry
, const char *name
,
354 void *value
, size_t size
, int type
)
356 struct posix_acl
*acl
;
359 acl
= xfs_get_acl(dentry
->d_inode
, type
);
365 error
= posix_acl_to_xattr(acl
, value
, size
);
366 posix_acl_release(acl
);
372 xfs_xattr_acl_set(struct dentry
*dentry
, const char *name
,
373 const void *value
, size_t size
, int flags
, int type
)
375 struct inode
*inode
= dentry
->d_inode
;
376 struct posix_acl
*acl
= NULL
;
379 if (flags
& XATTR_CREATE
)
381 if (type
== ACL_TYPE_DEFAULT
&& !S_ISDIR(inode
->i_mode
))
382 return value
? -EACCES
: 0;
383 if ((current_fsuid() != inode
->i_uid
) && !capable(CAP_FOWNER
))
389 acl
= posix_acl_from_xattr(value
, size
);
392 * acl_set_file(3) may request that we set default ACLs with
393 * zero length -- defend (gracefully) against that here.
398 error
= PTR_ERR(acl
);
402 error
= posix_acl_valid(acl
);
407 if (acl
->a_count
> XFS_ACL_MAX_ENTRIES
)
410 if (type
== ACL_TYPE_ACCESS
) {
411 mode_t mode
= inode
->i_mode
;
412 error
= posix_acl_equiv_mode(acl
, &mode
);
415 posix_acl_release(acl
);
422 error
= xfs_set_mode(inode
, mode
);
428 error
= xfs_set_acl(inode
, type
, acl
);
430 posix_acl_release(acl
);
435 const struct xattr_handler xfs_xattr_acl_access_handler
= {
436 .prefix
= POSIX_ACL_XATTR_ACCESS
,
437 .flags
= ACL_TYPE_ACCESS
,
438 .get
= xfs_xattr_acl_get
,
439 .set
= xfs_xattr_acl_set
,
442 const struct xattr_handler xfs_xattr_acl_default_handler
= {
443 .prefix
= POSIX_ACL_XATTR_DEFAULT
,
444 .flags
= ACL_TYPE_DEFAULT
,
445 .get
= xfs_xattr_acl_get
,
446 .set
= xfs_xattr_acl_set
,