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 "inode.h"
  34 #include "journal.h"
  35 #include "ocfs2_fs.h"
  36
  37 #include "xattr.h"
  38 #include "acl.h"
  39
  40 /*
  41  * Convert from xattr value to acl struct.
  42  */
  43 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  44 {
  45         int n, count;
  46         struct posix_acl *acl;
  47
  48         if (!value)
  49                 return NULL;
  50         if (size < sizeof(struct posix_acl_entry))
  51                 return ERR_PTR(-EINVAL);
  52
  53         count = size / sizeof(struct posix_acl_entry);
  54         if (count < 0)
  55                 return ERR_PTR(-EINVAL);
  56         if (count == 0)
  57                 return NULL;
  58
  59         acl = posix_acl_alloc(count, GFP_NOFS);
  60         if (!acl)
  61                 return ERR_PTR(-ENOMEM);
  62         for (n = 0; n < count; n++) {
  63                 struct ocfs2_acl_entry *entry =
  64                         (struct ocfs2_acl_entry *)value;
  65
  66                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  67                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  68                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
  69                 value += sizeof(struct posix_acl_entry);
  70
  71         }
  72         return acl;
  73 }
  74
  75 /*
  76  * Convert acl struct to xattr value.
  77  */
  78 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  79 {
  80         struct ocfs2_acl_entry *entry = NULL;
  81         char *ocfs2_acl;
  82         size_t n;
  83
  84         *size = acl->a_count * sizeof(struct posix_acl_entry);
  85
  86         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  87         if (!ocfs2_acl)
  88                 return ERR_PTR(-ENOMEM);
  89
  90         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  91         for (n = 0; n < acl->a_count; n++, entry++) {
  92                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  93                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  94                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
  95         }
  96         return ocfs2_acl;
  97 }
  98
  99 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 100                                               int type,
 101                                               struct buffer_head *di_bh)
 102 {
 103         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 104         int name_index;
 105         char *value = NULL;
 106         struct posix_acl *acl;
 107         int retval;
 108
 109         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 110                 return NULL;
 111
 112         switch (type) {
 113         case ACL_TYPE_ACCESS:
 114                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 115                 break;
 116         case ACL_TYPE_DEFAULT:
 117                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 118                 break;
 119         default:
 120                 return ERR_PTR(-EINVAL);
 121         }
 122
 123         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 124         if (retval > 0) {
 125                 value = kmalloc(retval, GFP_NOFS);
 126                 if (!value)
 127                         return ERR_PTR(-ENOMEM);
 128                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 129                                                 "", value, retval);
 130         }
 131
 132         if (retval > 0)
 133                 acl = ocfs2_acl_from_xattr(value, retval);
 134         else if (retval == -ENODATA || retval == 0)
 135                 acl = NULL;
 136         else
 137                 acl = ERR_PTR(retval);
 138
 139         kfree(value);
 140
 141         return acl;
 142 }
 143
 144
 145 /*
 146  * Get posix acl.
 147  */
 148 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 149 {
 150         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 151         struct buffer_head *di_bh = NULL;
 152         struct posix_acl *acl;
 153         int ret;
 154
 155         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 156                 return NULL;
 157
 158         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 159         if (ret < 0) {
 160                 mlog_errno(ret);
 161                 acl = ERR_PTR(ret);
 162                 return acl;
 163         }
 164
 165         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 166
 167         ocfs2_inode_unlock(inode, 0);
 168
 169         brelse(di_bh);
 170
 171         return acl;
 172 }
 173
 174 /*
 175  * Helper function to set i_mode in memory and disk. Some call paths
 176  * will not have di_bh or a journal handle to pass, in which case it
 177  * will create it's own.
 178  */
 179 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 180                               handle_t *handle, umode_t new_mode)
 181 {
 182         int ret, commit_handle = 0;
 183         struct ocfs2_dinode *di;
 184
 185         if (di_bh == NULL) {
 186                 ret = ocfs2_read_inode_block(inode, &di_bh);
 187                 if (ret) {
 188                         mlog_errno(ret);
 189                         goto out;
 190                 }
 191         } else
 192                 get_bh(di_bh);
 193
 194         if (handle == NULL) {
 195                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 196                                            OCFS2_INODE_UPDATE_CREDITS);
 197                 if (IS_ERR(handle)) {
 198                         ret = PTR_ERR(handle);
 199                         mlog_errno(ret);
 200                         goto out_brelse;
 201                 }
 202
 203                 commit_handle = 1;
 204         }
 205
 206         di = (struct ocfs2_dinode *)di_bh->b_data;
 207         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 208                                       OCFS2_JOURNAL_ACCESS_WRITE);
 209         if (ret) {
 210                 mlog_errno(ret);
 211                 goto out_commit;
 212         }
 213
 214         inode->i_mode = new_mode;
 215         di->i_mode = cpu_to_le16(inode->i_mode);
 216
 217         ocfs2_journal_dirty(handle, di_bh);
 218
 219 out_commit:
 220         if (commit_handle)
 221                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 222 out_brelse:
 223         brelse(di_bh);
 224 out:
 225         return ret;
 226 }
 227
 228 /*
 229  * Set the access or default ACL of an inode.
 230  */
 231 static int ocfs2_set_acl(handle_t *handle,
 232                          struct inode *inode,
 233                          struct buffer_head *di_bh,
 234                          int type,
 235                          struct posix_acl *acl,
 236                          struct ocfs2_alloc_context *meta_ac,
 237                          struct ocfs2_alloc_context *data_ac)
 238 {
 239         int name_index;
 240         void *value = NULL;
 241         size_t size = 0;
 242         int ret;
 243
 244         if (S_ISLNK(inode->i_mode))
 245                 return -EOPNOTSUPP;
 246
 247         switch (type) {
 248         case ACL_TYPE_ACCESS:
 249                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 250                 if (acl) {
 251                         mode_t mode = inode->i_mode;
 252                         ret = posix_acl_equiv_mode(acl, &mode);
 253                         if (ret < 0)
 254                                 return ret;
 255                         else {
 256                                 if (ret == 0)
 257                                         acl = NULL;
 258
 259                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 260                                                          handle, mode);
 261                                 if (ret)
 262                                         return ret;
 263
 264                         }
 265                 }
 266                 break;
 267         case ACL_TYPE_DEFAULT:
 268                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 269                 if (!S_ISDIR(inode->i_mode))
 270                         return acl ? -EACCES : 0;
 271                 break;
 272         default:
 273                 return -EINVAL;
 274         }
 275
 276         if (acl) {
 277                 value = ocfs2_acl_to_xattr(acl, &size);
 278                 if (IS_ERR(value))
 279                         return (int)PTR_ERR(value);
 280         }
 281
 282         if (handle)
 283                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 284                                              "", value, size, 0,
 285                                              meta_ac, data_ac);
 286         else
 287                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 288
 289         kfree(value);
 290
 291         return ret;
 292 }
 293
 294 int ocfs2_check_acl(struct inode *inode, int mask)
 295 {
 296         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 297         struct buffer_head *di_bh = NULL;
 298         struct posix_acl *acl;
 299         int ret = -EAGAIN;
 300
 301         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 302                 return ret;
 303
 304         ret = ocfs2_read_inode_block(inode, &di_bh);
 305         if (ret < 0) {
 306                 mlog_errno(ret);
 307                 return ret;
 308         }
 309
 310         acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);
 311
 312         brelse(di_bh);
 313
 314         if (IS_ERR(acl)) {
 315                 mlog_errno(PTR_ERR(acl));
 316                 return PTR_ERR(acl);
 317         }
 318         if (acl) {
 319                 ret = posix_acl_permission(inode, acl, mask);
 320                 posix_acl_release(acl);
 321                 return ret;
 322         }
 323
 324         return -EAGAIN;
 325 }
 326
 327 int ocfs2_acl_chmod(struct inode *inode)
 328 {
 329         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 330         struct posix_acl *acl, *clone;
 331         int ret;
 332
 333         if (S_ISLNK(inode->i_mode))
 334                 return -EOPNOTSUPP;
 335
 336         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 337                 return 0;
 338
 339         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 340         if (IS_ERR(acl) || !acl)
 341                 return PTR_ERR(acl);
 342         clone = posix_acl_clone(acl, GFP_KERNEL);
 343         posix_acl_release(acl);
 344         if (!clone)
 345                 return -ENOMEM;
 346         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 347         if (!ret)
 348                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 349                                     clone, NULL, NULL);
 350         posix_acl_release(clone);
 351         return ret;
 352 }
 353
 354 /*
 355  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 356  * then clone to new inode. Called from ocfs2_mknod.
 357  */
 358 int ocfs2_init_acl(handle_t *handle,
 359                    struct inode *inode,
 360                    struct inode *dir,
 361                    struct buffer_head *di_bh,
 362                    struct buffer_head *dir_bh,
 363                    struct ocfs2_alloc_context *meta_ac,
 364                    struct ocfs2_alloc_context *data_ac)
 365 {
 366         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 367         struct posix_acl *acl = NULL;
 368         int ret = 0, ret2;
 369         mode_t mode;
 370
 371         if (!S_ISLNK(inode->i_mode)) {
 372                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 373                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 374                                                    dir_bh);
 375                         if (IS_ERR(acl))
 376                                 return PTR_ERR(acl);
 377                 }
 378                 if (!acl) {
 379                         mode = inode->i_mode & ~current_umask();
 380                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 381                         if (ret) {
 382                                 mlog_errno(ret);
 383                                 goto cleanup;
 384                         }
 385                 }
 386         }
 387         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 388                 struct posix_acl *clone;
 389
 390                 if (S_ISDIR(inode->i_mode)) {
 391                         ret = ocfs2_set_acl(handle, inode, di_bh,
 392                                             ACL_TYPE_DEFAULT, acl,
 393                                             meta_ac, data_ac);
 394                         if (ret)
 395                                 goto cleanup;
 396                 }
 397                 clone = posix_acl_clone(acl, GFP_NOFS);
 398                 ret = -ENOMEM;
 399                 if (!clone)
 400                         goto cleanup;
 401
 402                 mode = inode->i_mode;
 403                 ret = posix_acl_create_masq(clone, &mode);
 404                 if (ret >= 0) {
 405                         ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 406                         if (ret2) {
 407                                 mlog_errno(ret2);
 408                                 ret = ret2;
 409                                 goto cleanup;
 410                         }
 411                         if (ret > 0) {
 412                                 ret = ocfs2_set_acl(handle, inode,
 413                                                     di_bh, ACL_TYPE_ACCESS,
 414                                                     clone, meta_ac, data_ac);
 415                         }
 416                 }
 417                 posix_acl_release(clone);
 418         }
 419 cleanup:
 420         posix_acl_release(acl);
 421         return ret;
 422 }
 423
 424 static size_t ocfs2_xattr_list_acl_access(struct inode *inode,
 425                                           char *list,
 426                                           size_t list_len,
 427                                           const char *name,
 428                                           size_t name_len)
 429 {
 430         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 431         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 432
 433         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 434                 return 0;
 435
 436         if (list && size <= list_len)
 437                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 438         return size;
 439 }
 440
 441 static size_t ocfs2_xattr_list_acl_default(struct inode *inode,
 442                                            char *list,
 443                                            size_t list_len,
 444                                            const char *name,
 445                                            size_t name_len)
 446 {
 447         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 448         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 449
 450         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 451                 return 0;
 452
 453         if (list && size <= list_len)
 454                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 455         return size;
 456 }
 457
 458 static int ocfs2_xattr_get_acl(struct inode *inode,
 459                                int type,
 460                                void *buffer,
 461                                size_t size)
 462 {
 463         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 464         struct posix_acl *acl;
 465         int ret;
 466
 467         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 468                 return -EOPNOTSUPP;
 469
 470         acl = ocfs2_get_acl(inode, type);
 471         if (IS_ERR(acl))
 472                 return PTR_ERR(acl);
 473         if (acl == NULL)
 474                 return -ENODATA;
 475         ret = posix_acl_to_xattr(acl, buffer, size);
 476         posix_acl_release(acl);
 477
 478         return ret;
 479 }
 480
 481 static int ocfs2_xattr_get_acl_access(struct inode *inode,
 482                                       const char *name,
 483                                       void *buffer,
 484                                       size_t size)
 485 {
 486         if (strcmp(name, "") != 0)
 487                 return -EINVAL;
 488         return ocfs2_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
 489 }
 490
 491 static int ocfs2_xattr_get_acl_default(struct inode *inode,
 492                                        const char *name,
 493                                        void *buffer,
 494                                        size_t size)
 495 {
 496         if (strcmp(name, "") != 0)
 497                 return -EINVAL;
 498         return ocfs2_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
 499 }
 500
 501 static int ocfs2_xattr_set_acl(struct inode *inode,
 502                                int type,
 503                                const void *value,
 504                                size_t size)
 505 {
 506         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 507         struct posix_acl *acl;
 508         int ret = 0;
 509
 510         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 511                 return -EOPNOTSUPP;
 512
 513         if (!is_owner_or_cap(inode))
 514                 return -EPERM;
 515
 516         if (value) {
 517                 acl = posix_acl_from_xattr(value, size);
 518                 if (IS_ERR(acl))
 519                         return PTR_ERR(acl);
 520                 else if (acl) {
 521                         ret = posix_acl_valid(acl);
 522                         if (ret)
 523                                 goto cleanup;
 524                 }
 525         } else
 526                 acl = NULL;
 527
 528         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 529
 530 cleanup:
 531         posix_acl_release(acl);
 532         return ret;
 533 }
 534
 535 static int ocfs2_xattr_set_acl_access(struct inode *inode,
 536                                       const char *name,
 537                                       const void *value,
 538                                       size_t size,
 539                                       int flags)
 540 {
 541         if (strcmp(name, "") != 0)
 542                 return -EINVAL;
 543         return ocfs2_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
 544 }
 545
 546 static int ocfs2_xattr_set_acl_default(struct inode *inode,
 547                                        const char *name,
 548                                        const void *value,
 549                                        size_t size,
 550                                        int flags)
 551 {
 552         if (strcmp(name, "") != 0)
 553                 return -EINVAL;
 554         return ocfs2_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
 555 }
 556
 557 struct xattr_handler ocfs2_xattr_acl_access_handler = {
 558         .prefix = POSIX_ACL_XATTR_ACCESS,
 559         .list   = ocfs2_xattr_list_acl_access,
 560         .get    = ocfs2_xattr_get_acl_access,
 561         .set    = ocfs2_xattr_set_acl_access,
 562 };
 563
 564 struct xattr_handler ocfs2_xattr_acl_default_handler = {
 565         .prefix = POSIX_ACL_XATTR_DEFAULT,
 566         .list   = ocfs2_xattr_list_acl_default,
 567         .get    = ocfs2_xattr_get_acl_default,
 568         .set    = ocfs2_xattr_set_acl_default,
 569 };