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
19 #include "xfs_log_format.h"
20 #include "xfs_trans_resv.h"
23 #include "xfs_bmap_btree.h"
24 #include "xfs_inode.h"
27 #include "xfs_mount.h"
28 #include "xfs_trace.h"
29 #include <linux/slab.h>
30 #include <linux/xattr.h>
31 #include <linux/posix_acl_xattr.h>
36 * - all ACL updates are protected by inode->i_mutex, which is taken before
37 * calling into this file.
40 STATIC struct posix_acl *
45 struct posix_acl_entry *acl_e;
46 struct posix_acl *acl;
47 struct xfs_acl_entry *ace;
48 unsigned int count, i;
50 count = be32_to_cpu(aclp->acl_cnt);
51 if (count > max_entries)
52 return ERR_PTR(-EFSCORRUPTED);
54 acl = posix_acl_alloc(count, GFP_KERNEL);
56 return ERR_PTR(-ENOMEM);
58 for (i = 0; i < count; i++) {
59 acl_e = &acl->a_entries[i];
60 ace = &aclp->acl_entry[i];
63 * The tag is 32 bits on disk and 16 bits in core.
65 * Because every access to it goes through the core
66 * format first this is not a problem.
68 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
69 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
71 switch (acl_e->e_tag) {
73 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
76 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
90 posix_acl_release(acl);
91 return ERR_PTR(-EINVAL);
95 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
97 const struct posix_acl_entry *acl_e;
98 struct xfs_acl_entry *ace;
101 aclp->acl_cnt = cpu_to_be32(acl->a_count);
102 for (i = 0; i < acl->a_count; i++) {
103 ace = &aclp->acl_entry[i];
104 acl_e = &acl->a_entries[i];
106 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
107 switch (acl_e->e_tag) {
109 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
112 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
115 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
119 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
124 xfs_get_acl(struct inode *inode, int type)
126 struct xfs_inode *ip = XFS_I(inode);
127 struct posix_acl *acl;
128 struct xfs_acl *xfs_acl;
129 unsigned char *ea_name;
133 acl = get_cached_acl(inode, type);
134 if (acl != ACL_NOT_CACHED)
137 trace_xfs_get_acl(ip);
140 case ACL_TYPE_ACCESS:
141 ea_name = SGI_ACL_FILE;
143 case ACL_TYPE_DEFAULT:
144 ea_name = SGI_ACL_DEFAULT;
151 * If we have a cached ACLs value just return it, not need to
152 * go out to the disk.
154 len = XFS_ACL_MAX_SIZE(ip->i_mount);
155 xfs_acl = kzalloc(len, GFP_KERNEL);
157 return ERR_PTR(-ENOMEM);
159 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
163 * If the attribute doesn't exist make sure we have a negative
164 * cache entry, for any other error assume it is transient and
165 * leave the cache entry as ACL_NOT_CACHED.
167 if (error == -ENOATTR) {
169 goto out_update_cache;
174 acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount));
179 set_cached_acl(inode, type, acl);
186 xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
188 struct xfs_inode *ip = XFS_I(inode);
189 unsigned char *ea_name;
192 if (S_ISLNK(inode->i_mode))
196 case ACL_TYPE_ACCESS:
197 ea_name = SGI_ACL_FILE;
199 case ACL_TYPE_DEFAULT:
200 if (!S_ISDIR(inode->i_mode))
201 return acl ? -EACCES : 0;
202 ea_name = SGI_ACL_DEFAULT;
209 struct xfs_acl *xfs_acl;
210 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
212 xfs_acl = kzalloc(len, GFP_KERNEL);
216 xfs_acl_to_disk(xfs_acl, acl);
218 /* subtract away the unused acl entries */
219 len -= sizeof(struct xfs_acl_entry) *
220 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
222 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
228 * A NULL ACL argument means we want to remove the ACL.
230 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
233 * If the attribute didn't exist to start with that's fine.
235 if (error == -ENOATTR)
240 set_cached_acl(inode, type, acl);
245 xfs_set_mode(struct inode *inode, umode_t mode)
249 if (mode != inode->i_mode) {
252 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
253 iattr.ia_mode = mode;
254 iattr.ia_ctime = current_fs_time(inode->i_sb);
256 error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
263 xfs_acl_exists(struct inode *inode, unsigned char *name)
265 int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb));
267 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
268 ATTR_ROOT|ATTR_KERNOVAL) == 0);
272 posix_acl_access_exists(struct inode *inode)
274 return xfs_acl_exists(inode, SGI_ACL_FILE);
278 posix_acl_default_exists(struct inode *inode)
280 if (!S_ISDIR(inode->i_mode))
282 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
286 * No need for i_mutex because the inode is not yet exposed to the VFS.
289 xfs_inherit_acl(struct inode *inode, struct posix_acl *acl)
291 umode_t mode = inode->i_mode;
292 int error = 0, inherit = 0;
294 if (S_ISDIR(inode->i_mode)) {
295 error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
300 error = posix_acl_create(&acl, GFP_KERNEL, &mode);
305 * If posix_acl_create returns a positive value we need to
306 * inherit a permission that can't be represented using the Unix
307 * mode bits and we actually need to set an ACL.
312 error = xfs_set_mode(inode, mode);
317 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
320 posix_acl_release(acl);
325 xfs_acl_chmod(struct inode *inode)
327 struct posix_acl *acl;
330 if (S_ISLNK(inode->i_mode))
333 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
334 if (IS_ERR(acl) || !acl)
337 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
341 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
342 posix_acl_release(acl);
347 xfs_xattr_acl_get(struct dentry *dentry, const char *name,
348 void *value, size_t size, int type)
350 struct posix_acl *acl;
353 acl = xfs_get_acl(dentry->d_inode, type);
359 error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
360 posix_acl_release(acl);
366 xfs_xattr_acl_set(struct dentry *dentry, const char *name,
367 const void *value, size_t size, int flags, int type)
369 struct inode *inode = dentry->d_inode;
370 struct posix_acl *acl = NULL;
373 if (flags & XATTR_CREATE)
375 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
376 return value ? -EACCES : 0;
377 if (!inode_owner_or_capable(inode))
383 acl = posix_acl_from_xattr(&init_user_ns, value, size);
386 * acl_set_file(3) may request that we set default ACLs with
387 * zero length -- defend (gracefully) against that here.
392 error = PTR_ERR(acl);
396 error = posix_acl_valid(acl);
401 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
404 if (type == ACL_TYPE_ACCESS) {
405 umode_t mode = inode->i_mode;
406 error = posix_acl_equiv_mode(acl, &mode);
409 posix_acl_release(acl);
416 error = xfs_set_mode(inode, mode);
422 error = xfs_set_acl(inode, type, acl);
424 posix_acl_release(acl);
429 const struct xattr_handler xfs_xattr_acl_access_handler = {
430 .prefix = POSIX_ACL_XATTR_ACCESS,
431 .flags = ACL_TYPE_ACCESS,
432 .get = xfs_xattr_acl_get,
433 .set = xfs_xattr_acl_set,
436 const struct xattr_handler xfs_xattr_acl_default_handler = {
437 .prefix = POSIX_ACL_XATTR_DEFAULT,
438 .flags = ACL_TYPE_DEFAULT,
439 .get = xfs_xattr_acl_get,
440 .set = xfs_xattr_acl_set,