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"
19 #include "xfs_trans.h"
21 #include <linux/posix_acl_xattr.h>
25 * - all ACL updates are protected by inode->i_mutex, which is taken before
26 * calling into this file.
29 STATIC struct posix_acl *
32 const struct xfs_acl *aclp,
36 struct posix_acl_entry *acl_e;
37 struct posix_acl *acl;
38 const struct xfs_acl_entry *ace;
39 unsigned int count, i;
41 if (len < sizeof(*aclp)) {
42 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
44 return ERR_PTR(-EFSCORRUPTED);
47 count = be32_to_cpu(aclp->acl_cnt);
48 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
49 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
51 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 = make_kuid(&init_user_ns,
74 be32_to_cpu(ace->ae_id));
77 acl_e->e_gid = make_kgid(&init_user_ns,
78 be32_to_cpu(ace->ae_id));
92 posix_acl_release(acl);
93 return ERR_PTR(-EINVAL);
97 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
99 const struct posix_acl_entry *acl_e;
100 struct xfs_acl_entry *ace;
103 aclp->acl_cnt = cpu_to_be32(acl->a_count);
104 for (i = 0; i < acl->a_count; i++) {
105 ace = &aclp->acl_entry[i];
106 acl_e = &acl->a_entries[i];
108 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
109 switch (acl_e->e_tag) {
111 ace->ae_id = cpu_to_be32(
112 from_kuid(&init_user_ns, acl_e->e_uid));
115 ace->ae_id = cpu_to_be32(
116 from_kgid(&init_user_ns, acl_e->e_gid));
119 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
123 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
128 xfs_get_acl(struct inode *inode, int type)
130 struct xfs_inode *ip = XFS_I(inode);
131 struct xfs_mount *mp = ip->i_mount;
132 struct posix_acl *acl = NULL;
133 struct xfs_da_args args = {
135 .attr_filter = XFS_ATTR_ROOT,
136 .valuelen = XFS_ACL_MAX_SIZE(mp),
140 trace_xfs_get_acl(ip);
143 case ACL_TYPE_ACCESS:
144 args.name = SGI_ACL_FILE;
146 case ACL_TYPE_DEFAULT:
147 args.name = SGI_ACL_DEFAULT;
152 args.namelen = strlen(args.name);
155 * If the attribute doesn't exist make sure we have a negative cache
156 * entry, for any other error assume it is transient.
158 error = xfs_attr_get(&args);
160 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
161 XFS_ACL_MAX_ENTRIES(mp));
162 } else if (error != -ENOATTR) {
163 acl = ERR_PTR(error);
166 kmem_free(args.value);
171 __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
173 struct xfs_inode *ip = XFS_I(inode);
174 struct xfs_da_args args = {
176 .attr_filter = XFS_ATTR_ROOT,
181 case ACL_TYPE_ACCESS:
182 args.name = SGI_ACL_FILE;
184 case ACL_TYPE_DEFAULT:
185 if (!S_ISDIR(inode->i_mode))
186 return acl ? -EACCES : 0;
187 args.name = SGI_ACL_DEFAULT;
192 args.namelen = strlen(args.name);
195 args.valuelen = XFS_ACL_SIZE(acl->a_count);
196 args.value = kvzalloc(args.valuelen, GFP_KERNEL);
199 xfs_acl_to_disk(args.value, acl);
202 error = xfs_attr_set(&args);
203 kmem_free(args.value);
206 * If the attribute didn't exist to start with that's fine.
208 if (!acl && error == -ENOATTR)
211 set_cached_acl(inode, type, acl);
220 struct xfs_inode *ip = XFS_I(inode);
221 struct xfs_mount *mp = ip->i_mount;
222 struct xfs_trans *tp;
225 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
229 xfs_ilock(ip, XFS_ILOCK_EXCL);
230 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
231 inode->i_mode = mode;
232 inode->i_ctime = current_time(inode);
233 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
235 if (mp->m_flags & XFS_MOUNT_WSYNC)
236 xfs_trans_set_sync(tp);
237 return xfs_trans_commit(tp);
241 xfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
242 struct posix_acl *acl, int type)
245 bool set_mode = false;
252 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
255 if (type == ACL_TYPE_ACCESS) {
256 error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
264 * We set the mode after successfully updating the ACL xattr because the
265 * xattr update can fail at ENOSPC and we don't want to change the mode
266 * if the ACL update hasn't been applied.
268 error = __xfs_set_acl(inode, acl, type);
269 if (!error && set_mode && mode != inode->i_mode)
270 error = xfs_acl_set_mode(inode, mode);
275 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
276 * We don't validate the content whatsoever so it is caller responsibility to
277 * provide data in valid format and ensure i_mode is consistent.
284 if (!strcmp(name, SGI_ACL_FILE))
285 forget_cached_acl(inode, ACL_TYPE_ACCESS);
286 else if (!strcmp(name, SGI_ACL_DEFAULT))
287 forget_cached_acl(inode, ACL_TYPE_DEFAULT);