1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 */
6
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/completion.h>
11 #include <linux/buffer_head.h>
12 #include <linux/xattr.h>
13 #include <linux/posix_acl.h>
14 #include <linux/posix_acl_xattr.h>
15 #include <linux/gfs2_ondisk.h>
16
17 #include "gfs2.h"
18 #include "incore.h"
19 #include "acl.h"
20 #include "xattr.h"
21 #include "glock.h"
22 #include "inode.h"
23 #include "meta_io.h"
24 #include "quota.h"
25 #include "rgrp.h"
26 #include "trans.h"
27 #include "util.h"
28
29 static const char *gfs2_acl_name(int type)
30 {
31 switch (type) {
32 case ACL_TYPE_ACCESS:
33 return XATTR_POSIX_ACL_ACCESS;
34 case ACL_TYPE_DEFAULT:
35 return XATTR_POSIX_ACL_DEFAULT;
36 }
37 return NULL;
38 }
39
40 static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
41 {
42 struct gfs2_inode *ip = GFS2_I(inode);
43 struct posix_acl *acl;
44 const char *name;
45 char *data;
46 int len;
47
48 if (!ip->i_eattr)
49 return NULL;
50
51 name = gfs2_acl_name(type);
52 len = gfs2_xattr_acl_get(ip, name, &data);
53 if (len <= 0)
54 return ERR_PTR(len);
55 acl = posix_acl_from_xattr(&init_user_ns, data, len);
56 kfree(data);
57 return acl;
58 }
59
60 struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
61 {
62 struct gfs2_inode *ip = GFS2_I(inode);
63 struct gfs2_holder gh;
64 bool need_unlock = false;
65 struct posix_acl *acl;
66
67 if (rcu)
68 return ERR_PTR(-ECHILD);
69
70 if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
71 int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
72 LM_FLAG_ANY, &gh);
73 if (ret)
74 return ERR_PTR(ret);
75 need_unlock = true;
76 }
77 acl = __gfs2_get_acl(inode, type);
78 if (need_unlock)
79 gfs2_glock_dq_uninit(&gh);
80 return acl;
81 }
82
83 int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
84 {
85 int error;
86 size_t len;
87 char *data;
88 const char *name = gfs2_acl_name(type);
89
90 if (acl) {
91 len = posix_acl_xattr_size(acl->a_count);
92 data = kmalloc(len, GFP_NOFS);
93 if (data == NULL)
94 return -ENOMEM;
95 error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
96 if (error < 0)
97 goto out;
98 } else {
99 data = NULL;
100 len = 0;
101 }
102
103 error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
104 if (error)
105 goto out;
106 set_cached_acl(inode, type, acl);
107 out:
108 kfree(data);
109 return error;
110 }
111
112 int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
113 struct posix_acl *acl, int type)
114 {
115 struct inode *inode = d_inode(dentry);
116 struct gfs2_inode *ip = GFS2_I(inode);
117 struct gfs2_holder gh;
118 bool need_unlock = false;
119 int ret;
120 umode_t mode;
121
122 if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
123 return -E2BIG;
124
125 ret = gfs2_qa_get(ip);
126 if (ret)
127 return ret;
128
129 if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
130 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
131 if (ret)
132 goto out;
133 need_unlock = true;
134 }
135
136 mode = inode->i_mode;
137 if (type == ACL_TYPE_ACCESS && acl) {
138 ret = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
139 if (ret)
140 goto unlock;
141 }
142
143 ret = __gfs2_set_acl(inode, acl, type);
144 if (!ret && mode != inode->i_mode) {
145 inode_set_ctime_current(inode);
146 inode->i_mode = mode;
147 mark_inode_dirty(inode);
148 }
149 unlock:
150 if (need_unlock)
151 gfs2_glock_dq_uninit(&gh);
152 out:
153 gfs2_qa_put(ip);
154 return ret;
155 }
156
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