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 
gfs2_acl_name(int type)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 
__gfs2_get_acl(struct inode * inode,int type)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 
gfs2_get_acl(struct inode * inode,int type,bool rcu)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 
__gfs2_set_acl(struct inode * inode,struct posix_acl * acl,int type)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 
gfs2_set_acl(struct user_namespace * mnt_userns,struct inode * inode,struct posix_acl * acl,int type)112 int gfs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
113 		 struct posix_acl *acl, int type)
114 {
115 	struct gfs2_inode *ip = GFS2_I(inode);
116 	struct gfs2_holder gh;
117 	bool need_unlock = false;
118 	int ret;
119 	umode_t mode;
120 
121 	if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
122 		return -E2BIG;
123 
124 	ret = gfs2_qa_get(ip);
125 	if (ret)
126 		return ret;
127 
128 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
129 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
130 		if (ret)
131 			goto out;
132 		need_unlock = true;
133 	}
134 
135 	mode = inode->i_mode;
136 	if (type == ACL_TYPE_ACCESS && acl) {
137 		ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
138 		if (ret)
139 			goto unlock;
140 	}
141 
142 	ret = __gfs2_set_acl(inode, acl, type);
143 	if (!ret && mode != inode->i_mode) {
144 		inode->i_ctime = current_time(inode);
145 		inode->i_mode = mode;
146 		mark_inode_dirty(inode);
147 	}
148 unlock:
149 	if (need_unlock)
150 		gfs2_glock_dq_uninit(&gh);
151 out:
152 	gfs2_qa_put(ip);
153 	return ret;
154 }
155