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/posix_acl.h> 16#include <linux/posix_acl_xattr.h> 17#include <linux/gfs2_ondisk.h> 18#include <linux/lm_interface.h> 19 20#include "gfs2.h" 21#include "incore.h" 22#include "acl.h" 23#include "eaops.h" 24#include "eattr.h" 25#include "glock.h" 26#include "inode.h" 27#include "meta_io.h" 28#include "trans.h" 29#include "util.h" 30 31#define ACL_ACCESS 1 32#define ACL_DEFAULT 0 33 34int gfs2_acl_validate_set(struct gfs2_inode *ip, int access, 35 struct gfs2_ea_request *er, 36 int *remove, mode_t *mode) 37{ 38 struct posix_acl *acl; 39 int error; 40 41 error = gfs2_acl_validate_remove(ip, access); 42 if (error) 43 return error; 44 45 if (!er->er_data) 46 return -EINVAL; 47 48 acl = posix_acl_from_xattr(er->er_data, er->er_data_len); 49 if (IS_ERR(acl)) 50 return PTR_ERR(acl); 51 if (!acl) { 52 *remove = 1; 53 return 0; 54 } 55 56 error = posix_acl_valid(acl); 57 if (error) 58 goto out; 59 60 if (access) { 61 error = posix_acl_equiv_mode(acl, mode); 62 if (!error) 63 *remove = 1; 64 else if (error > 0) 65 error = 0; 66 } 67 68out: 69 posix_acl_release(acl); 70 return error; 71} 72 73int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access) 74{ 75 if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl) 76 return -EOPNOTSUPP; 77 if (current->fsuid != ip->i_inode.i_uid && !capable(CAP_FOWNER)) 78 return -EPERM; 79 if (S_ISLNK(ip->i_inode.i_mode)) 80 return -EOPNOTSUPP; 81 if (!access && !S_ISDIR(ip->i_inode.i_mode)) 82 return -EACCES; 83 84 return 0; 85} 86 87static int acl_get(struct gfs2_inode *ip, int access, struct posix_acl **acl, 88 struct gfs2_ea_location *el, char **data, unsigned int *len) 89{ 90 struct gfs2_ea_request er; 91 struct gfs2_ea_location el_this; 92 int error; 93 94 if (!ip->i_di.di_eattr) 95 return 0; 96 97 memset(&er, 0, sizeof(struct gfs2_ea_request)); 98 if (access) { 99 er.er_name = GFS2_POSIX_ACL_ACCESS; 100 er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN; 101 } else { 102 er.er_name = GFS2_POSIX_ACL_DEFAULT; 103 er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN; 104 } 105 er.er_type = GFS2_EATYPE_SYS; 106 107 if (!el) 108 el = &el_this; 109 110 error = gfs2_ea_find(ip, &er, el); 111 if (error) 112 return error; 113 if (!el->el_ea) 114 return 0; 115 if (!GFS2_EA_DATA_LEN(el->el_ea)) 116 goto out; 117 118 er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea); 119 er.er_data = kmalloc(er.er_data_len, GFP_KERNEL); 120 error = -ENOMEM; 121 if (!er.er_data) 122 goto out; 123 124 error = gfs2_ea_get_copy(ip, el, er.er_data); 125 if (error) 126 goto out_kfree; 127 128 if (acl) { 129 *acl = posix_acl_from_xattr(er.er_data, er.er_data_len); 130 if (IS_ERR(*acl)) 131 error = PTR_ERR(*acl); 132 } 133 134out_kfree: 135 if (error || !data) 136 kfree(er.er_data); 137 else { 138 *data = er.er_data; 139 *len = er.er_data_len; 140 } 141out: 142 if (error || el == &el_this) 143 brelse(el->el_bh); 144 return error; 145} 146 147/** 148 * gfs2_check_acl - Check an ACL to see if we're allowed to do something 149 * @inode: the file we want to do something to 150 * @mask: what we want to do 151 * 152 * Returns: errno 153 */ 154 155int gfs2_check_acl(struct inode *inode, int mask) 156{ 157 struct posix_acl *acl = NULL; 158 int error; 159 160 error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL); 161 if (error) 162 return error; 163 164 if (acl) { 165 error = posix_acl_permission(inode, acl, mask); 166 posix_acl_release(acl); 167 return error; 168 } 169 170 return -EAGAIN; 171} 172 173static int munge_mode(struct gfs2_inode *ip, mode_t mode) 174{ 175 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 176 struct buffer_head *dibh; 177 int error; 178 179 error = gfs2_trans_begin(sdp, RES_DINODE, 0); 180 if (error) 181 return error; 182 183 error = gfs2_meta_inode_buffer(ip, &dibh); 184 if (!error) { 185 gfs2_assert_withdraw(sdp, 186 (ip->i_inode.i_mode & S_IFMT) == (mode & S_IFMT)); 187 ip->i_inode.i_mode = mode; 188 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 189 gfs2_dinode_out(ip, dibh->b_data); 190 brelse(dibh); 191 } 192 193 gfs2_trans_end(sdp); 194 195 return 0; 196} 197 198int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip) 199{ 200 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); 201 struct posix_acl *acl = NULL, *clone; 202 struct gfs2_ea_request er; 203 mode_t mode = ip->i_inode.i_mode; 204 int error; 205 206 if (!sdp->sd_args.ar_posix_acl) 207 return 0; 208 if (S_ISLNK(ip->i_inode.i_mode)) 209 return 0; 210 211 memset(&er, 0, sizeof(struct gfs2_ea_request)); 212 er.er_type = GFS2_EATYPE_SYS; 213 214 error = acl_get(dip, ACL_DEFAULT, &acl, NULL, 215 &er.er_data, &er.er_data_len); 216 if (error) 217 return error; 218 if (!acl) { 219 mode &= ~current->fs->umask; 220 if (mode != ip->i_inode.i_mode) 221 error = munge_mode(ip, mode); 222 return error; 223 } 224 225 clone = posix_acl_clone(acl, GFP_KERNEL); 226 error = -ENOMEM; 227 if (!clone) 228 goto out; 229 posix_acl_release(acl); 230 acl = clone; 231 232 if (S_ISDIR(ip->i_inode.i_mode)) { 233 er.er_name = GFS2_POSIX_ACL_DEFAULT; 234 er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN; 235 error = gfs2_system_eaops.eo_set(ip, &er); 236 if (error) 237 goto out; 238 } 239 240 error = posix_acl_create_masq(acl, &mode); 241 if (error < 0) 242 goto out; 243 if (error > 0) { 244 er.er_name = GFS2_POSIX_ACL_ACCESS; 245 er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN; 246 posix_acl_to_xattr(acl, er.er_data, er.er_data_len); 247 er.er_mode = mode; 248 er.er_flags = GFS2_ERF_MODE; 249 error = gfs2_system_eaops.eo_set(ip, &er); 250 if (error) 251 goto out; 252 } else 253 munge_mode(ip, mode); 254 255out: 256 posix_acl_release(acl); 257 kfree(er.er_data); 258 return error; 259} 260 261int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr) 262{ 263 struct posix_acl *acl = NULL, *clone; 264 struct gfs2_ea_location el; 265 char *data; 266 unsigned int len; 267 int error; 268 269 error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len); 270 if (error) 271 return error; 272 if (!acl) 273 return gfs2_setattr_simple(ip, attr); 274 275 clone = posix_acl_clone(acl, GFP_KERNEL); 276 error = -ENOMEM; 277 if (!clone) 278 goto out; 279 posix_acl_release(acl); 280 acl = clone; 281 282 error = posix_acl_chmod_masq(acl, attr->ia_mode); 283 if (!error) { 284 posix_acl_to_xattr(acl, data, len); 285 error = gfs2_ea_acl_chmod(ip, &el, attr, data); 286 } 287 288out: 289 posix_acl_release(acl); 290 brelse(el.el_bh); 291 kfree(data); 292 return error; 293} 294