1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2008, Christoph Hellwig
7 #include "xfs_shared.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_inode.h"
14 #include "xfs_trace.h"
15 #include "xfs_error.h"
17 #include "xfs_da_format.h"
18 #include "xfs_da_btree.h"
20 #include <linux/posix_acl_xattr.h>
24 * - all ACL updates are protected by inode->i_mutex, which is taken before
25 * calling into this file.
28 STATIC struct posix_acl *
31 const struct xfs_acl *aclp,
35 struct posix_acl_entry *acl_e;
36 struct posix_acl *acl;
37 const struct xfs_acl_entry *ace;
38 unsigned int count, i;
40 if (len < sizeof(*aclp)) {
41 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
43 return ERR_PTR(-EFSCORRUPTED);
46 count = be32_to_cpu(aclp->acl_cnt);
47 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
48 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
50 return ERR_PTR(-EFSCORRUPTED);
53 acl = posix_acl_alloc(count, GFP_KERNEL);
55 return ERR_PTR(-ENOMEM);
57 for (i = 0; i < count; i++) {
58 acl_e = &acl->a_entries[i];
59 ace = &aclp->acl_entry[i];
62 * The tag is 32 bits on disk and 16 bits in core.
64 * Because every access to it goes through the core
65 * format first this is not a problem.
67 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
68 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
70 switch (acl_e->e_tag) {
72 acl_e->e_uid = make_kuid(&init_user_ns,
73 be32_to_cpu(ace->ae_id));
76 acl_e->e_gid = make_kgid(&init_user_ns,
77 be32_to_cpu(ace->ae_id));
91 posix_acl_release(acl);
92 return ERR_PTR(-EINVAL);
96 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
98 const struct posix_acl_entry *acl_e;
99 struct xfs_acl_entry *ace;
102 aclp->acl_cnt = cpu_to_be32(acl->a_count);
103 for (i = 0; i < acl->a_count; i++) {
104 ace = &aclp->acl_entry[i];
105 acl_e = &acl->a_entries[i];
107 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
108 switch (acl_e->e_tag) {
110 ace->ae_id = cpu_to_be32(
111 from_kuid(&init_user_ns, acl_e->e_uid));
114 ace->ae_id = cpu_to_be32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
118 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
122 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
127 xfs_get_acl(struct inode *inode, int type)
129 struct xfs_inode *ip = XFS_I(inode);
130 struct xfs_mount *mp = ip->i_mount;
131 struct posix_acl *acl = NULL;
132 struct xfs_da_args args = {
134 .attr_filter = XFS_ATTR_ROOT,
135 .valuelen = XFS_ACL_MAX_SIZE(mp),
139 trace_xfs_get_acl(ip);
142 case ACL_TYPE_ACCESS:
143 args.name = SGI_ACL_FILE;
145 case ACL_TYPE_DEFAULT:
146 args.name = SGI_ACL_DEFAULT;
151 args.namelen = strlen(args.name);
154 * If the attribute doesn't exist make sure we have a negative cache
155 * entry, for any other error assume it is transient.
157 error = xfs_attr_get(&args);
159 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
160 XFS_ACL_MAX_ENTRIES(mp));
161 } else if (error != -ENOATTR) {
162 acl = ERR_PTR(error);
165 kmem_free(args.value);
170 __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
172 struct xfs_inode *ip = XFS_I(inode);
173 struct xfs_da_args args = {
175 .attr_filter = XFS_ATTR_ROOT,
180 case ACL_TYPE_ACCESS:
181 args.name = SGI_ACL_FILE;
183 case ACL_TYPE_DEFAULT:
184 if (!S_ISDIR(inode->i_mode))
185 return acl ? -EACCES : 0;
186 args.name = SGI_ACL_DEFAULT;
191 args.namelen = strlen(args.name);
194 args.valuelen = XFS_ACL_SIZE(acl->a_count);
195 args.value = kvzalloc(args.valuelen, GFP_KERNEL);
198 xfs_acl_to_disk(args.value, acl);
201 error = xfs_attr_set(&args);
202 kmem_free(args.value);
205 * If the attribute didn't exist to start with that's fine.
207 if (!acl && error == -ENOATTR)
210 set_cached_acl(inode, type, acl);
215 xfs_set_mode(struct inode *inode, umode_t mode)
219 if (mode != inode->i_mode) {
222 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
223 iattr.ia_mode = mode;
224 iattr.ia_ctime = current_time(inode);
226 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
233 xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
236 bool set_mode = false;
243 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
246 if (type == ACL_TYPE_ACCESS) {
247 error = posix_acl_update_mode(inode, &mode, &acl);
254 error = __xfs_set_acl(inode, acl, type);
259 * We set the mode after successfully updating the ACL xattr because the
260 * xattr update can fail at ENOSPC and we don't want to change the mode
261 * if the ACL update hasn't been applied.
264 error = xfs_set_mode(inode, mode);
270 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
271 * We don't validate the content whatsoever so it is caller responsibility to
272 * provide data in valid format and ensure i_mode is consistent.
279 if (!strcmp(name, SGI_ACL_FILE))
280 forget_cached_acl(inode, ACL_TYPE_ACCESS);
281 else if (!strcmp(name, SGI_ACL_DEFAULT))
282 forget_cached_acl(inode, ACL_TYPE_DEFAULT);