fs/ocfs2/acl.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * acl.c
   5  *
   6  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   7  *
   8  * CREDITS:
   9  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
  10  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public
  14  * License version 2 as published by the Free Software Foundation.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/string.h>
  25
  26 #define MLOG_MASK_PREFIX ML_INODE
  27 #include <cluster/masklog.h>
  28
  29 #include "ocfs2.h"
  30 #include "alloc.h"
  31 #include "dlmglue.h"
  32 #include "file.h"
  33 #include "ocfs2_fs.h"
  34
  35 #include "xattr.h"
  36 #include "acl.h"
  37
  38 /*
  39  * Convert from xattr value to acl struct.
  40  */
  41 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  42 {
  43         int n, count;
  44         struct posix_acl *acl;
  45
  46         if (!value)
  47                 return NULL;
  48         if (size < sizeof(struct posix_acl_entry))
  49                 return ERR_PTR(-EINVAL);
  50
  51         count = size / sizeof(struct posix_acl_entry);
  52         if (count < 0)
  53                 return ERR_PTR(-EINVAL);
  54         if (count == 0)
  55                 return NULL;
  56
  57         acl = posix_acl_alloc(count, GFP_NOFS);
  58         if (!acl)
  59                 return ERR_PTR(-ENOMEM);
  60         for (n = 0; n < count; n++) {
  61                 struct ocfs2_acl_entry *entry =
  62                         (struct ocfs2_acl_entry *)value;
  63
  64                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  65                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  66                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
  67                 value += sizeof(struct posix_acl_entry);
  68
  69         }
  70         return acl;
  71 }
  72
  73 /*
  74  * Convert acl struct to xattr value.
  75  */
  76 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  77 {
  78         struct ocfs2_acl_entry *entry = NULL;
  79         char *ocfs2_acl;
  80         size_t n;
  81
  82         *size = acl->a_count * sizeof(struct posix_acl_entry);
  83
  84         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  85         if (!ocfs2_acl)
  86                 return ERR_PTR(-ENOMEM);
  87
  88         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  89         for (n = 0; n < acl->a_count; n++, entry++) {
  90                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  91                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  92                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
  93         }
  94         return ocfs2_acl;
  95 }
  96
  97 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
  98                                               int type,
  99                                               struct buffer_head *di_bh)
 100 {
 101         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 102         int name_index;
 103         char *value = NULL;
 104         struct posix_acl *acl;
 105         int retval;
 106
 107         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 108                 return NULL;
 109
 110         switch (type) {
 111         case ACL_TYPE_ACCESS:
 112                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 113                 break;
 114         case ACL_TYPE_DEFAULT:
 115                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 116                 break;
 117         default:
 118                 return ERR_PTR(-EINVAL);
 119         }
 120
 121         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 122         if (retval > 0) {
 123                 value = kmalloc(retval, GFP_NOFS);
 124                 if (!value)
 125                         return ERR_PTR(-ENOMEM);
 126                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 127                                                 "", value, retval);
 128         }
 129
 130         if (retval > 0)
 131                 acl = ocfs2_acl_from_xattr(value, retval);
 132         else if (retval == -ENODATA || retval == 0)
 133                 acl = NULL;
 134         else
 135                 acl = ERR_PTR(retval);
 136
 137         kfree(value);
 138
 139         return acl;
 140 }
 141
 142
 143 /*
 144  * Get posix acl.
 145  */
 146 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 147 {
 148         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 149         struct buffer_head *di_bh = NULL;
 150         struct posix_acl *acl;
 151         int ret;
 152
 153         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 154                 return NULL;
 155
 156         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 157         if (ret < 0) {
 158                 mlog_errno(ret);
 159                 acl = ERR_PTR(ret);
 160                 return acl;
 161         }
 162
 163         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 164
 165         ocfs2_inode_unlock(inode, 0);
 166
 167         brelse(di_bh);
 168
 169         return acl;
 170 }
 171
 172 /*
 173  * Set the access or default ACL of an inode.
 174  */
 175 static int ocfs2_set_acl(handle_t *handle,
 176                          struct inode *inode,
 177                          struct buffer_head *di_bh,
 178                          int type,
 179                          struct posix_acl *acl,
 180                          struct ocfs2_alloc_context *meta_ac,
 181                          struct ocfs2_alloc_context *data_ac)
 182 {
 183         int name_index;
 184         void *value = NULL;
 185         size_t size = 0;
 186         int ret;
 187
 188         if (S_ISLNK(inode->i_mode))
 189                 return -EOPNOTSUPP;
 190
 191         switch (type) {
 192         case ACL_TYPE_ACCESS:
 193                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 194                 if (acl) {
 195                         mode_t mode = inode->i_mode;
 196                         ret = posix_acl_equiv_mode(acl, &mode);
 197                         if (ret < 0)
 198                                 return ret;
 199                         else {
 200                                 inode->i_mode = mode;
 201                                 if (ret == 0)
 202                                         acl = NULL;
 203                         }
 204                 }
 205                 break;
 206         case ACL_TYPE_DEFAULT:
 207                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 208                 if (!S_ISDIR(inode->i_mode))
 209                         return acl ? -EACCES : 0;
 210                 break;
 211         default:
 212                 return -EINVAL;
 213         }
 214
 215         if (acl) {
 216                 value = ocfs2_acl_to_xattr(acl, &size);
 217                 if (IS_ERR(value))
 218                         return (int)PTR_ERR(value);
 219         }
 220
 221         if (handle)
 222                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 223                                              "", value, size, 0,
 224                                              meta_ac, data_ac);
 225         else
 226                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 227
 228         kfree(value);
 229
 230         return ret;
 231 }
 232
 233 int ocfs2_check_acl(struct inode *inode, int mask)
 234 {
 235         struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 236
 237         if (IS_ERR(acl))
 238                 return PTR_ERR(acl);
 239         if (acl) {
 240                 int ret = posix_acl_permission(inode, acl, mask);
 241                 posix_acl_release(acl);
 242                 return ret;
 243         }
 244
 245         return -EAGAIN;
 246 }
 247
 248 int ocfs2_acl_chmod(struct inode *inode)
 249 {
 250         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 251         struct posix_acl *acl, *clone;
 252         int ret;
 253
 254         if (S_ISLNK(inode->i_mode))
 255                 return -EOPNOTSUPP;
 256
 257         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 258                 return 0;
 259
 260         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 261         if (IS_ERR(acl) || !acl)
 262                 return PTR_ERR(acl);
 263         clone = posix_acl_clone(acl, GFP_KERNEL);
 264         posix_acl_release(acl);
 265         if (!clone)
 266                 return -ENOMEM;
 267         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 268         if (!ret)
 269                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 270                                     clone, NULL, NULL);
 271         posix_acl_release(clone);
 272         return ret;
 273 }
 274
 275 /*
 276  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 277  * then clone to new inode. Called from ocfs2_mknod.
 278  */
 279 int ocfs2_init_acl(handle_t *handle,
 280                    struct inode *inode,
 281                    struct inode *dir,
 282                    struct buffer_head *di_bh,
 283                    struct buffer_head *dir_bh,
 284                    struct ocfs2_alloc_context *meta_ac,
 285                    struct ocfs2_alloc_context *data_ac)
 286 {
 287         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 288         struct posix_acl *acl = NULL;
 289         int ret = 0;
 290
 291         if (!S_ISLNK(inode->i_mode)) {
 292                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 293                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 294                                                    dir_bh);
 295                         if (IS_ERR(acl))
 296                                 return PTR_ERR(acl);
 297                 }
 298                 if (!acl)
 299                         inode->i_mode &= ~current_umask();
 300         }
 301         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 302                 struct posix_acl *clone;
 303                 mode_t mode;
 304
 305                 if (S_ISDIR(inode->i_mode)) {
 306                         ret = ocfs2_set_acl(handle, inode, di_bh,
 307                                             ACL_TYPE_DEFAULT, acl,
 308                                             meta_ac, data_ac);
 309                         if (ret)
 310                                 goto cleanup;
 311                 }
 312                 clone = posix_acl_clone(acl, GFP_NOFS);
 313                 ret = -ENOMEM;
 314                 if (!clone)
 315                         goto cleanup;
 316
 317                 mode = inode->i_mode;
 318                 ret = posix_acl_create_masq(clone, &mode);
 319                 if (ret >= 0) {
 320                         inode->i_mode = mode;
 321                         if (ret > 0) {
 322                                 ret = ocfs2_set_acl(handle, inode,
 323                                                     di_bh, ACL_TYPE_ACCESS,
 324                                                     clone, meta_ac, data_ac);
 325                         }
 326                 }
 327                 posix_acl_release(clone);
 328         }
 329 cleanup:
 330         posix_acl_release(acl);
 331         return ret;
 332 }
 333
 334 static size_t ocfs2_xattr_list_acl_access(struct inode *inode,
 335                                           char *list,
 336                                           size_t list_len,
 337                                           const char *name,
 338                                           size_t name_len)
 339 {
 340         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 341         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 342
 343         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 344                 return 0;
 345
 346         if (list && size <= list_len)
 347                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 348         return size;
 349 }
 350
 351 static size_t ocfs2_xattr_list_acl_default(struct inode *inode,
 352                                            char *list,
 353                                            size_t list_len,
 354                                            const char *name,
 355                                            size_t name_len)
 356 {
 357         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 358         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 359
 360         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 361                 return 0;
 362
 363         if (list && size <= list_len)
 364                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 365         return size;
 366 }
 367
 368 static int ocfs2_xattr_get_acl(struct inode *inode,
 369                                int type,
 370                                void *buffer,
 371                                size_t size)
 372 {
 373         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 374         struct posix_acl *acl;
 375         int ret;
 376
 377         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 378                 return -EOPNOTSUPP;
 379
 380         acl = ocfs2_get_acl(inode, type);
 381         if (IS_ERR(acl))
 382                 return PTR_ERR(acl);
 383         if (acl == NULL)
 384                 return -ENODATA;
 385         ret = posix_acl_to_xattr(acl, buffer, size);
 386         posix_acl_release(acl);
 387
 388         return ret;
 389 }
 390
 391 static int ocfs2_xattr_get_acl_access(struct inode *inode,
 392                                       const char *name,
 393                                       void *buffer,
 394                                       size_t size)
 395 {
 396         if (strcmp(name, "") != 0)
 397                 return -EINVAL;
 398         return ocfs2_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
 399 }
 400
 401 static int ocfs2_xattr_get_acl_default(struct inode *inode,
 402                                        const char *name,
 403                                        void *buffer,
 404                                        size_t size)
 405 {
 406         if (strcmp(name, "") != 0)
 407                 return -EINVAL;
 408         return ocfs2_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
 409 }
 410
 411 static int ocfs2_xattr_set_acl(struct inode *inode,
 412                                int type,
 413                                const void *value,
 414                                size_t size)
 415 {
 416         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 417         struct posix_acl *acl;
 418         int ret = 0;
 419
 420         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 421                 return -EOPNOTSUPP;
 422
 423         if (!is_owner_or_cap(inode))
 424                 return -EPERM;
 425
 426         if (value) {
 427                 acl = posix_acl_from_xattr(value, size);
 428                 if (IS_ERR(acl))
 429                         return PTR_ERR(acl);
 430                 else if (acl) {
 431                         ret = posix_acl_valid(acl);
 432                         if (ret)
 433                                 goto cleanup;
 434                 }
 435         } else
 436                 acl = NULL;
 437
 438         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 439
 440 cleanup:
 441         posix_acl_release(acl);
 442         return ret;
 443 }
 444
 445 static int ocfs2_xattr_set_acl_access(struct inode *inode,
 446                                       const char *name,
 447                                       const void *value,
 448                                       size_t size,
 449                                       int flags)
 450 {
 451         if (strcmp(name, "") != 0)
 452                 return -EINVAL;
 453         return ocfs2_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
 454 }
 455
 456 static int ocfs2_xattr_set_acl_default(struct inode *inode,
 457                                        const char *name,
 458                                        const void *value,
 459                                        size_t size,
 460                                        int flags)
 461 {
 462         if (strcmp(name, "") != 0)
 463                 return -EINVAL;
 464         return ocfs2_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
 465 }
 466
 467 struct xattr_handler ocfs2_xattr_acl_access_handler = {
 468         .prefix = POSIX_ACL_XATTR_ACCESS,
 469         .list   = ocfs2_xattr_list_acl_access,
 470         .get    = ocfs2_xattr_get_acl_access,
 471         .set    = ocfs2_xattr_set_acl_access,
 472 };
 473
 474 struct xattr_handler ocfs2_xattr_acl_default_handler = {
 475         .prefix = POSIX_ACL_XATTR_DEFAULT,
 476         .list   = ocfs2_xattr_list_acl_default,
 477         .get    = ocfs2_xattr_get_acl_default,
 478         .set    = ocfs2_xattr_set_acl_default,
 479 };