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 "trans.h" 28 #include "util.h" 29 30 static const char *gfs2_acl_name(int type) 31 { 32 switch (type) { 33 case ACL_TYPE_ACCESS: 34 return GFS2_POSIX_ACL_ACCESS; 35 case ACL_TYPE_DEFAULT: 36 return GFS2_POSIX_ACL_DEFAULT; 37 } 38 return NULL; 39 } 40 41 struct posix_acl *gfs2_get_acl(struct inode *inode, int type) 42 { 43 struct gfs2_inode *ip = GFS2_I(inode); 44 struct posix_acl *acl; 45 const char *name; 46 char *data; 47 int len; 48 49 if (!ip->i_eattr) 50 return NULL; 51 52 acl = get_cached_acl(&ip->i_inode, type); 53 if (acl != ACL_NOT_CACHED) 54 return acl; 55 56 name = gfs2_acl_name(type); 57 if (name == NULL) 58 return ERR_PTR(-EINVAL); 59 60 len = gfs2_xattr_acl_get(ip, name, &data); 61 if (len < 0) 62 return ERR_PTR(len); 63 if (len == 0) 64 return NULL; 65 66 acl = posix_acl_from_xattr(&init_user_ns, data, len); 67 kfree(data); 68 return acl; 69 } 70 71 static int gfs2_set_mode(struct inode *inode, umode_t mode) 72 { 73 int error = 0; 74 75 if (mode != inode->i_mode) { 76 inode->i_mode = mode; 77 mark_inode_dirty(inode); 78 } 79 80 return error; 81 } 82 83 static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl) 84 { 85 int error; 86 int len; 87 char *data; 88 const char *name = gfs2_acl_name(type); 89 90 BUG_ON(name == NULL); 91 len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); 92 if (len == 0) 93 return 0; 94 data = kmalloc(len, GFP_NOFS); 95 if (data == NULL) 96 return -ENOMEM; 97 error = posix_acl_to_xattr(&init_user_ns, acl, data, len); 98 if (error < 0) 99 goto out; 100 error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS); 101 if (!error) 102 set_cached_acl(inode, type, acl); 103 out: 104 kfree(data); 105 return error; 106 } 107 108 int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode) 109 { 110 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); 111 struct posix_acl *acl; 112 umode_t mode = inode->i_mode; 113 int error = 0; 114 115 if (!sdp->sd_args.ar_posix_acl) 116 return 0; 117 if (S_ISLNK(inode->i_mode)) 118 return 0; 119 120 acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT); 121 if (IS_ERR(acl)) 122 return PTR_ERR(acl); 123 if (!acl) { 124 mode &= ~current_umask(); 125 return gfs2_set_mode(inode, mode); 126 } 127 128 if (S_ISDIR(inode->i_mode)) { 129 error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl); 130 if (error) 131 goto out; 132 } 133 134 error = __posix_acl_create(&acl, GFP_NOFS, &mode); 135 if (error < 0) 136 return error; 137 138 if (error == 0) 139 goto munge; 140 141 error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl); 142 if (error) 143 goto out; 144 munge: 145 error = gfs2_set_mode(inode, mode); 146 out: 147 posix_acl_release(acl); 148 return error; 149 } 150 151 int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr) 152 { 153 struct inode *inode = &ip->i_inode; 154 struct posix_acl *acl; 155 char *data; 156 unsigned int len; 157 int error; 158 159 acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS); 160 if (IS_ERR(acl)) 161 return PTR_ERR(acl); 162 if (!acl) 163 return gfs2_setattr_simple(inode, attr); 164 165 error = __posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode); 166 if (error) 167 return error; 168 169 len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); 170 data = kmalloc(len, GFP_NOFS); 171 error = -ENOMEM; 172 if (data == NULL) 173 goto out; 174 posix_acl_to_xattr(&init_user_ns, acl, data, len); 175 error = gfs2_xattr_acl_chmod(ip, attr, data); 176 kfree(data); 177 set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl); 178 179 out: 180 posix_acl_release(acl); 181 return error; 182 } 183 184 static int gfs2_acl_type(const char *name) 185 { 186 if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0) 187 return ACL_TYPE_ACCESS; 188 if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0) 189 return ACL_TYPE_DEFAULT; 190 return -EINVAL; 191 } 192 193 static int gfs2_xattr_system_get(struct dentry *dentry, const char *name, 194 void *buffer, size_t size, int xtype) 195 { 196 struct inode *inode = dentry->d_inode; 197 struct gfs2_sbd *sdp = GFS2_SB(inode); 198 struct posix_acl *acl; 199 int type; 200 int error; 201 202 if (!sdp->sd_args.ar_posix_acl) 203 return -EOPNOTSUPP; 204 205 type = gfs2_acl_type(name); 206 if (type < 0) 207 return type; 208 209 acl = gfs2_get_acl(inode, type); 210 if (IS_ERR(acl)) 211 return PTR_ERR(acl); 212 if (acl == NULL) 213 return -ENODATA; 214 215 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); 216 posix_acl_release(acl); 217 218 return error; 219 } 220 221 static int gfs2_xattr_system_set(struct dentry *dentry, const char *name, 222 const void *value, size_t size, int flags, 223 int xtype) 224 { 225 struct inode *inode = dentry->d_inode; 226 struct gfs2_sbd *sdp = GFS2_SB(inode); 227 struct posix_acl *acl = NULL; 228 int error = 0, type; 229 230 if (!sdp->sd_args.ar_posix_acl) 231 return -EOPNOTSUPP; 232 233 type = gfs2_acl_type(name); 234 if (type < 0) 235 return type; 236 if (flags & XATTR_CREATE) 237 return -EINVAL; 238 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) 239 return value ? -EACCES : 0; 240 if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER)) 241 return -EPERM; 242 if (S_ISLNK(inode->i_mode)) 243 return -EOPNOTSUPP; 244 245 if (!value) 246 goto set_acl; 247 248 acl = posix_acl_from_xattr(&init_user_ns, value, size); 249 if (!acl) { 250 /* 251 * acl_set_file(3) may request that we set default ACLs with 252 * zero length -- defend (gracefully) against that here. 253 */ 254 goto out; 255 } 256 if (IS_ERR(acl)) { 257 error = PTR_ERR(acl); 258 goto out; 259 } 260 261 error = posix_acl_valid(acl); 262 if (error) 263 goto out_release; 264 265 error = -EINVAL; 266 if (acl->a_count > GFS2_ACL_MAX_ENTRIES) 267 goto out_release; 268 269 if (type == ACL_TYPE_ACCESS) { 270 umode_t mode = inode->i_mode; 271 error = posix_acl_equiv_mode(acl, &mode); 272 273 if (error <= 0) { 274 posix_acl_release(acl); 275 acl = NULL; 276 277 if (error < 0) 278 return error; 279 } 280 281 error = gfs2_set_mode(inode, mode); 282 if (error) 283 goto out_release; 284 } 285 286 set_acl: 287 error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS); 288 if (!error) { 289 if (acl) 290 set_cached_acl(inode, type, acl); 291 else 292 forget_cached_acl(inode, type); 293 } 294 out_release: 295 posix_acl_release(acl); 296 out: 297 return error; 298 } 299 300 const struct xattr_handler gfs2_xattr_system_handler = { 301 .prefix = XATTR_SYSTEM_PREFIX, 302 .flags = GFS2_EATYPE_SYS, 303 .get = gfs2_xattr_system_get, 304 .set = gfs2_xattr_system_set, 305 }; 306 307