1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/xattr.h>
16 #include <linux/posix_acl.h>
17 #include <linux/posix_acl_xattr.h>
18 #include <linux/gfs2_ondisk.h>
19 
20 #include "gfs2.h"
21 #include "incore.h"
22 #include "acl.h"
23 #include "xattr.h"
24 #include "glock.h"
25 #include "inode.h"
26 #include "meta_io.h"
27 #include "rgrp.h"
28 #include "trans.h"
29 #include "util.h"
30 
gfs2_acl_name(int type)31 static const char *gfs2_acl_name(int type)
32 {
33 	switch (type) {
34 	case ACL_TYPE_ACCESS:
35 		return XATTR_POSIX_ACL_ACCESS;
36 	case ACL_TYPE_DEFAULT:
37 		return XATTR_POSIX_ACL_DEFAULT;
38 	}
39 	return NULL;
40 }
41 
__gfs2_get_acl(struct inode * inode,int type)42 static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
43 {
44 	struct gfs2_inode *ip = GFS2_I(inode);
45 	struct posix_acl *acl;
46 	const char *name;
47 	char *data;
48 	int len;
49 
50 	if (!ip->i_eattr)
51 		return NULL;
52 
53 	name = gfs2_acl_name(type);
54 	len = gfs2_xattr_acl_get(ip, name, &data);
55 	if (len <= 0)
56 		return ERR_PTR(len);
57 	acl = posix_acl_from_xattr(&init_user_ns, data, len);
58 	kfree(data);
59 	return acl;
60 }
61 
gfs2_get_acl(struct inode * inode,int type)62 struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
63 {
64 	struct gfs2_inode *ip = GFS2_I(inode);
65 	struct gfs2_holder gh;
66 	bool need_unlock = false;
67 	struct posix_acl *acl;
68 
69 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
70 		int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
71 					     LM_FLAG_ANY, &gh);
72 		if (ret)
73 			return ERR_PTR(ret);
74 		need_unlock = true;
75 	}
76 	acl = __gfs2_get_acl(inode, type);
77 	if (need_unlock)
78 		gfs2_glock_dq_uninit(&gh);
79 	return acl;
80 }
81 
__gfs2_set_acl(struct inode * inode,struct posix_acl * acl,int type)82 int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
83 {
84 	int error;
85 	size_t len;
86 	char *data;
87 	const char *name = gfs2_acl_name(type);
88 
89 	if (acl) {
90 		len = posix_acl_xattr_size(acl->a_count);
91 		data = kmalloc(len, GFP_NOFS);
92 		if (data == NULL)
93 			return -ENOMEM;
94 		error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
95 		if (error < 0)
96 			goto out;
97 	} else {
98 		data = NULL;
99 		len = 0;
100 	}
101 
102 	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
103 	if (error)
104 		goto out;
105 	set_cached_acl(inode, type, acl);
106 out:
107 	kfree(data);
108 	return error;
109 }
110 
gfs2_set_acl(struct inode * inode,struct posix_acl * acl,int type)111 int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
112 {
113 	struct gfs2_inode *ip = GFS2_I(inode);
114 	struct gfs2_holder gh;
115 	bool need_unlock = false;
116 	int ret;
117 	umode_t mode;
118 
119 	if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
120 		return -E2BIG;
121 
122 	ret = gfs2_rsqa_alloc(ip);
123 	if (ret)
124 		return ret;
125 
126 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
127 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
128 		if (ret)
129 			return ret;
130 		need_unlock = true;
131 	}
132 
133 	mode = inode->i_mode;
134 	if (type == ACL_TYPE_ACCESS && acl) {
135 		ret = posix_acl_update_mode(inode, &mode, &acl);
136 		if (ret)
137 			goto unlock;
138 	}
139 
140 	ret = __gfs2_set_acl(inode, acl, type);
141 	if (!ret && mode != inode->i_mode) {
142 		inode->i_ctime = current_time(inode);
143 		inode->i_mode = mode;
144 		mark_inode_dirty(inode);
145 	}
146 unlock:
147 	if (need_unlock)
148 		gfs2_glock_dq_uninit(&gh);
149 	return ret;
150 }
151