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Dave Chinner0b61f8a2018-06-05 19:42:14 -07001// SPDX-License-Identifier: GPL-2.0
Christoph Hellwigef14f0c2009-06-10 17:07:47 +02002/*
3 * Copyright (c) 2008, Christoph Hellwig
4 * All Rights Reserved.
Christoph Hellwigef14f0c2009-06-10 17:07:47 +02005 */
6#include "xfs.h"
Darrick J. Wong5467b342019-06-28 19:25:35 -07007#include "xfs_shared.h"
Dave Chinnera4fbe6a2013-10-23 10:51:50 +11008#include "xfs_format.h"
Dave Chinner69432832013-08-12 20:49:23 +10009#include "xfs_log_format.h"
Dave Chinner7fd36c42013-08-12 20:49:32 +100010#include "xfs_trans_resv.h"
Dave Chinner0a8aa192013-06-05 12:09:10 +100011#include "xfs_mount.h"
Dave Chinnera4fbe6a2013-10-23 10:51:50 +110012#include "xfs_inode.h"
Dave Chinnera4fbe6a2013-10-23 10:51:50 +110013#include "xfs_attr.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000014#include "xfs_trace.h"
Darrick J. Wonga5155b82019-11-02 09:40:53 -070015#include "xfs_error.h"
Darrick J. Wong5f213dd2019-11-06 17:19:33 -080016#include "xfs_acl.h"
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020017
Darrick J. Wong5f213dd2019-11-06 17:19:33 -080018#include <linux/posix_acl_xattr.h>
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020019
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020020/*
21 * Locking scheme:
22 * - all ACL updates are protected by inode->i_mutex, which is taken before
23 * calling into this file.
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020024 */
25
26STATIC struct posix_acl *
Dave Chinner0a8aa192013-06-05 12:09:10 +100027xfs_acl_from_disk(
Darrick J. Wonga5155b82019-11-02 09:40:53 -070028 struct xfs_mount *mp,
Andreas Gruenbacher86a21c72015-11-03 12:41:59 +110029 const struct xfs_acl *aclp,
30 int len,
31 int max_entries)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020032{
33 struct posix_acl_entry *acl_e;
34 struct posix_acl *acl;
Andreas Gruenbacher86a21c72015-11-03 12:41:59 +110035 const struct xfs_acl_entry *ace;
Xi Wang093019c2011-12-12 21:55:52 +000036 unsigned int count, i;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020037
Darrick J. Wonga5155b82019-11-02 09:40:53 -070038 if (len < sizeof(*aclp)) {
39 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
40 len);
Andreas Gruenbacher86a21c72015-11-03 12:41:59 +110041 return ERR_PTR(-EFSCORRUPTED);
Darrick J. Wonga5155b82019-11-02 09:40:53 -070042 }
43
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020044 count = be32_to_cpu(aclp->acl_cnt);
Darrick J. Wonga5155b82019-11-02 09:40:53 -070045 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
46 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
47 len);
Christoph Hellwigfa8b18e2011-11-20 15:35:32 +000048 return ERR_PTR(-EFSCORRUPTED);
Darrick J. Wonga5155b82019-11-02 09:40:53 -070049 }
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020050
51 acl = posix_acl_alloc(count, GFP_KERNEL);
52 if (!acl)
53 return ERR_PTR(-ENOMEM);
54
55 for (i = 0; i < count; i++) {
56 acl_e = &acl->a_entries[i];
57 ace = &aclp->acl_entry[i];
58
59 /*
60 * The tag is 32 bits on disk and 16 bits in core.
61 *
62 * Because every access to it goes through the core
63 * format first this is not a problem.
64 */
65 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
66 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
67
68 switch (acl_e->e_tag) {
69 case ACL_USER:
Dwight Engen288bbe02013-08-15 14:07:59 -040070 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
71 break;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020072 case ACL_GROUP:
Dwight Engen288bbe02013-08-15 14:07:59 -040073 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020074 break;
75 case ACL_USER_OBJ:
76 case ACL_GROUP_OBJ:
77 case ACL_MASK:
78 case ACL_OTHER:
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020079 break;
80 default:
81 goto fail;
82 }
83 }
84 return acl;
85
86fail:
87 posix_acl_release(acl);
88 return ERR_PTR(-EINVAL);
89}
90
91STATIC void
92xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
93{
94 const struct posix_acl_entry *acl_e;
95 struct xfs_acl_entry *ace;
96 int i;
97
98 aclp->acl_cnt = cpu_to_be32(acl->a_count);
99 for (i = 0; i < acl->a_count; i++) {
100 ace = &aclp->acl_entry[i];
101 acl_e = &acl->a_entries[i];
102
103 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
Dwight Engen288bbe02013-08-15 14:07:59 -0400104 switch (acl_e->e_tag) {
105 case ACL_USER:
106 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
107 break;
108 case ACL_GROUP:
109 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
110 break;
111 default:
112 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
113 break;
114 }
115
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200116 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
117 }
118}
119
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200120struct posix_acl *
121xfs_get_acl(struct inode *inode, int type)
122{
123 struct xfs_inode *ip = XFS_I(inode);
Christoph Hellwig2401dc22013-12-20 05:16:50 -0800124 struct posix_acl *acl = NULL;
Dave Chinnerddbca702019-08-29 09:04:10 -0700125 struct xfs_acl *xfs_acl = NULL;
Dave Chinnera9273ca2010-01-20 10:47:48 +1100126 unsigned char *ea_name;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200127 int error;
Dave Chinner0a8aa192013-06-05 12:09:10 +1000128 int len;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200129
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200130 trace_xfs_get_acl(ip);
131
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200132 switch (type) {
133 case ACL_TYPE_ACCESS:
134 ea_name = SGI_ACL_FILE;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200135 break;
136 case ACL_TYPE_DEFAULT:
137 ea_name = SGI_ACL_DEFAULT;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200138 break;
139 default:
Al Viro1cbd20d2009-06-09 13:29:39 -0400140 BUG();
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200141 }
142
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200143 /*
144 * If we have a cached ACLs value just return it, not need to
145 * go out to the disk.
146 */
Dave Chinner0a8aa192013-06-05 12:09:10 +1000147 len = XFS_ACL_MAX_SIZE(ip->i_mount);
Dave Chinnerddbca702019-08-29 09:04:10 -0700148 error = xfs_attr_get(ip, ea_name, (unsigned char **)&xfs_acl, &len,
149 ATTR_ALLOC | ATTR_ROOT);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200150 if (error) {
151 /*
152 * If the attribute doesn't exist make sure we have a negative
Andreas Gruenbacherb8a7a3a2016-03-24 14:38:37 +0100153 * cache entry, for any other error assume it is transient.
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200154 */
Andreas Gruenbacherb8a7a3a2016-03-24 14:38:37 +0100155 if (error != -ENOATTR)
156 acl = ERR_PTR(error);
157 } else {
Darrick J. Wonga5155b82019-11-02 09:40:53 -0700158 acl = xfs_acl_from_disk(ip->i_mount, xfs_acl, len,
Andreas Gruenbacherb8a7a3a2016-03-24 14:38:37 +0100159 XFS_ACL_MAX_ENTRIES(ip->i_mount));
Dave Chinnerddbca702019-08-29 09:04:10 -0700160 kmem_free(xfs_acl);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200161 }
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200162 return acl;
163}
164
Jan Kara8ba35872017-06-26 08:48:18 -0700165int
166__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200167{
168 struct xfs_inode *ip = XFS_I(inode);
Dave Chinnera9273ca2010-01-20 10:47:48 +1100169 unsigned char *ea_name;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200170 int error;
171
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200172 switch (type) {
173 case ACL_TYPE_ACCESS:
174 ea_name = SGI_ACL_FILE;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200175 break;
176 case ACL_TYPE_DEFAULT:
177 if (!S_ISDIR(inode->i_mode))
178 return acl ? -EACCES : 0;
179 ea_name = SGI_ACL_DEFAULT;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200180 break;
181 default:
182 return -EINVAL;
183 }
184
185 if (acl) {
186 struct xfs_acl *xfs_acl;
Dave Chinner0a8aa192013-06-05 12:09:10 +1000187 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200188
Tetsuo Handa707e0dd2019-08-26 12:06:22 -0700189 xfs_acl = kmem_zalloc_large(len, 0);
Dave Chinnerfdd3cce2013-09-02 20:53:00 +1000190 if (!xfs_acl)
191 return -ENOMEM;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200192
193 xfs_acl_to_disk(xfs_acl, acl);
Dave Chinner0a8aa192013-06-05 12:09:10 +1000194
195 /* subtract away the unused acl entries */
196 len -= sizeof(struct xfs_acl_entry) *
197 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200198
Dave Chinner24513372014-06-25 14:58:08 +1000199 error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200200 len, ATTR_ROOT);
201
Dave Chinnerfdd3cce2013-09-02 20:53:00 +1000202 kmem_free(xfs_acl);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200203 } else {
204 /*
205 * A NULL ACL argument means we want to remove the ACL.
206 */
Dave Chinner24513372014-06-25 14:58:08 +1000207 error = xfs_attr_remove(ip, ea_name, ATTR_ROOT);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200208
209 /*
210 * If the attribute didn't exist to start with that's fine.
211 */
212 if (error == -ENOATTR)
213 error = 0;
214 }
215
216 if (!error)
Al Viro1cbd20d2009-06-09 13:29:39 -0400217 set_cached_acl(inode, type, acl);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200218 return error;
219}
220
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200221static int
Al Virod3fb6122011-07-23 18:37:50 -0400222xfs_set_mode(struct inode *inode, umode_t mode)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200223{
224 int error = 0;
225
226 if (mode != inode->i_mode) {
227 struct iattr iattr;
228
Christoph Hellwigd6d59ba2009-12-23 16:09:13 +0000229 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200230 iattr.ia_mode = mode;
Deepa Dinamanic2050a42016-09-14 07:48:06 -0700231 iattr.ia_ctime = current_time(inode);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200232
Dave Chinner24513372014-06-25 14:58:08 +1000233 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200234 }
235
236 return error;
237}
238
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200239int
Christoph Hellwig2401dc22013-12-20 05:16:50 -0800240xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200241{
Dave Chinner67f2ffe2017-10-09 11:37:23 -0700242 umode_t mode;
243 bool set_mode = false;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000244 int error = 0;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200245
Christoph Hellwig2401dc22013-12-20 05:16:50 -0800246 if (!acl)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200247 goto set_acl;
248
Jie Liu4ae69fe2014-02-07 15:26:11 +1100249 error = -E2BIG;
Dave Chinner0a8aa192013-06-05 12:09:10 +1000250 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
Christoph Hellwig2401dc22013-12-20 05:16:50 -0800251 return error;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200252
253 if (type == ACL_TYPE_ACCESS) {
Jan Kara07393102016-09-19 17:39:09 +0200254 error = posix_acl_update_mode(inode, &mode, &acl);
255 if (error)
256 return error;
Dave Chinner67f2ffe2017-10-09 11:37:23 -0700257 set_mode = true;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200258 }
259
260 set_acl:
Dave Chinner67f2ffe2017-10-09 11:37:23 -0700261 error = __xfs_set_acl(inode, acl, type);
262 if (error)
263 return error;
264
265 /*
266 * We set the mode after successfully updating the ACL xattr because the
267 * xattr update can fail at ENOSPC and we don't want to change the mode
268 * if the ACL update hasn't been applied.
269 */
270 if (set_mode)
271 error = xfs_set_mode(inode, mode);
272
273 return error;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200274}