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 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 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 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 82 int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) 83 { 84 int error; 85 int len; 86 char *data; 87 const char *name = gfs2_acl_name(type); 88 89 if (acl) { 90 len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); 91 if (len == 0) 92 return 0; 93 data = kmalloc(len, GFP_NOFS); 94 if (data == NULL) 95 return -ENOMEM; 96 error = posix_acl_to_xattr(&init_user_ns, acl, data, len); 97 if (error < 0) 98 goto out; 99 } else { 100 data = NULL; 101 len = 0; 102 } 103 104 error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS); 105 if (error) 106 goto out; 107 set_cached_acl(inode, type, acl); 108 out: 109 kfree(data); 110 return error; 111 } 112 113 int gfs2_set_acl(struct inode *inode, 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_rsqa_alloc(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 return ret; 132 need_unlock = true; 133 } 134 135 mode = inode->i_mode; 136 if (type == ACL_TYPE_ACCESS && acl) { 137 ret = posix_acl_update_mode(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 return ret; 152 } 153