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/slab.h>
  25 #include <linux/string.h>
  26
  27 #define MLOG_MASK_PREFIX ML_INODE
  28 #include <cluster/masklog.h>
  29
  30 #include "ocfs2.h"
  31 #include "alloc.h"
  32 #include "dlmglue.h"
  33 #include "file.h"
  34 #include "inode.h"
  35 #include "journal.h"
  36 #include "ocfs2_fs.h"
  37
  38 #include "xattr.h"
  39 #include "acl.h"
  40
  41 /*
  42  * Convert from xattr value to acl struct.
  43  */
  44 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  45 {
  46         int n, count;
  47         struct posix_acl *acl;
  48
  49         if (!value)
  50                 return NULL;
  51         if (size < sizeof(struct posix_acl_entry))
  52                 return ERR_PTR(-EINVAL);
  53
  54         count = size / sizeof(struct posix_acl_entry);
  55         if (count < 0)
  56                 return ERR_PTR(-EINVAL);
  57         if (count == 0)
  58                 return NULL;
  59
  60         acl = posix_acl_alloc(count, GFP_NOFS);
  61         if (!acl)
  62                 return ERR_PTR(-ENOMEM);
  63         for (n = 0; n < count; n++) {
  64                 struct ocfs2_acl_entry *entry =
  65                         (struct ocfs2_acl_entry *)value;
  66
  67                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  68                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  69                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
  70                 value += sizeof(struct posix_acl_entry);
  71
  72         }
  73         return acl;
  74 }
  75
  76 /*
  77  * Convert acl struct to xattr value.
  78  */
  79 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  80 {
  81         struct ocfs2_acl_entry *entry = NULL;
  82         char *ocfs2_acl;
  83         size_t n;
  84
  85         *size = acl->a_count * sizeof(struct posix_acl_entry);
  86
  87         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  88         if (!ocfs2_acl)
  89                 return ERR_PTR(-ENOMEM);
  90
  91         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  92         for (n = 0; n < acl->a_count; n++, entry++) {
  93                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  94                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  95                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
  96         }
  97         return ocfs2_acl;
  98 }
  99
 100 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 101                                               int type,
 102                                               struct buffer_head *di_bh)
 103 {
 104         int name_index;
 105         char *value = NULL;
 106         struct posix_acl *acl;
 107         int retval;
 108
 109         switch (type) {
 110         case ACL_TYPE_ACCESS:
 111                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 112                 break;
 113         case ACL_TYPE_DEFAULT:
 114                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 115                 break;
 116         default:
 117                 return ERR_PTR(-EINVAL);
 118         }
 119
 120         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 121         if (retval > 0) {
 122                 value = kmalloc(retval, GFP_NOFS);
 123                 if (!value)
 124                         return ERR_PTR(-ENOMEM);
 125                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 126                                                 "", value, retval);
 127         }
 128
 129         if (retval > 0)
 130                 acl = ocfs2_acl_from_xattr(value, retval);
 131         else if (retval == -ENODATA || retval == 0)
 132                 acl = NULL;
 133         else
 134                 acl = ERR_PTR(retval);
 135
 136         kfree(value);
 137
 138         return acl;
 139 }
 140
 141
 142 /*
 143  * Get posix acl.
 144  */
 145 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 146 {
 147         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 148         struct buffer_head *di_bh = NULL;
 149         struct posix_acl *acl;
 150         int ret;
 151
 152         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 153                 return NULL;
 154
 155         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 156         if (ret < 0) {
 157                 mlog_errno(ret);
 158                 acl = ERR_PTR(ret);
 159                 return acl;
 160         }
 161
 162         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 163
 164         ocfs2_inode_unlock(inode, 0);
 165
 166         brelse(di_bh);
 167
 168         return acl;
 169 }
 170
 171 /*
 172  * Helper function to set i_mode in memory and disk. Some call paths
 173  * will not have di_bh or a journal handle to pass, in which case it
 174  * will create it's own.
 175  */
 176 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 177                               handle_t *handle, umode_t new_mode)
 178 {
 179         int ret, commit_handle = 0;
 180         struct ocfs2_dinode *di;
 181
 182         if (di_bh == NULL) {
 183                 ret = ocfs2_read_inode_block(inode, &di_bh);
 184                 if (ret) {
 185                         mlog_errno(ret);
 186                         goto out;
 187                 }
 188         } else
 189                 get_bh(di_bh);
 190
 191         if (handle == NULL) {
 192                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 193                                            OCFS2_INODE_UPDATE_CREDITS);
 194                 if (IS_ERR(handle)) {
 195                         ret = PTR_ERR(handle);
 196                         mlog_errno(ret);
 197                         goto out_brelse;
 198                 }
 199
 200                 commit_handle = 1;
 201         }
 202
 203         di = (struct ocfs2_dinode *)di_bh->b_data;
 204         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 205                                       OCFS2_JOURNAL_ACCESS_WRITE);
 206         if (ret) {
 207                 mlog_errno(ret);
 208                 goto out_commit;
 209         }
 210
 211         inode->i_mode = new_mode;
 212         inode->i_ctime = CURRENT_TIME;
 213         di->i_mode = cpu_to_le16(inode->i_mode);
 214         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 215         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 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, unsigned int flags)
 295 {
 296         struct ocfs2_super *osb;
 297         struct buffer_head *di_bh = NULL;
 298         struct posix_acl *acl;
 299         int ret = -EAGAIN;
 300
 301         if (flags & IPERM_FLAG_RCU)
 302                 return -ECHILD;
 303
 304         osb = OCFS2_SB(inode->i_sb);
 305         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 306                 return ret;
 307
 308         ret = ocfs2_read_inode_block(inode, &di_bh);
 309         if (ret < 0) {
 310                 mlog_errno(ret);
 311                 return ret;
 312         }
 313
 314         acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);
 315
 316         brelse(di_bh);
 317
 318         if (IS_ERR(acl)) {
 319                 mlog_errno(PTR_ERR(acl));
 320                 return PTR_ERR(acl);
 321         }
 322         if (acl) {
 323                 ret = posix_acl_permission(inode, acl, mask);
 324                 posix_acl_release(acl);
 325                 return ret;
 326         }
 327
 328         return -EAGAIN;
 329 }
 330
 331 int ocfs2_acl_chmod(struct inode *inode)
 332 {
 333         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 334         struct posix_acl *acl, *clone;
 335         int ret;
 336
 337         if (S_ISLNK(inode->i_mode))
 338                 return -EOPNOTSUPP;
 339
 340         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 341                 return 0;
 342
 343         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 344         if (IS_ERR(acl) || !acl)
 345                 return PTR_ERR(acl);
 346         clone = posix_acl_clone(acl, GFP_KERNEL);
 347         posix_acl_release(acl);
 348         if (!clone)
 349                 return -ENOMEM;
 350         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 351         if (!ret)
 352                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 353                                     clone, NULL, NULL);
 354         posix_acl_release(clone);
 355         return ret;
 356 }
 357
 358 /*
 359  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 360  * then clone to new inode. Called from ocfs2_mknod.
 361  */
 362 int ocfs2_init_acl(handle_t *handle,
 363                    struct inode *inode,
 364                    struct inode *dir,
 365                    struct buffer_head *di_bh,
 366                    struct buffer_head *dir_bh,
 367                    struct ocfs2_alloc_context *meta_ac,
 368                    struct ocfs2_alloc_context *data_ac)
 369 {
 370         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 371         struct posix_acl *acl = NULL;
 372         int ret = 0, ret2;
 373         mode_t mode;
 374
 375         if (!S_ISLNK(inode->i_mode)) {
 376                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 377                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 378                                                    dir_bh);
 379                         if (IS_ERR(acl))
 380                                 return PTR_ERR(acl);
 381                 }
 382                 if (!acl) {
 383                         mode = inode->i_mode & ~current_umask();
 384                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 385                         if (ret) {
 386                                 mlog_errno(ret);
 387                                 goto cleanup;
 388                         }
 389                 }
 390         }
 391         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 392                 struct posix_acl *clone;
 393
 394                 if (S_ISDIR(inode->i_mode)) {
 395                         ret = ocfs2_set_acl(handle, inode, di_bh,
 396                                             ACL_TYPE_DEFAULT, acl,
 397                                             meta_ac, data_ac);
 398                         if (ret)
 399                                 goto cleanup;
 400                 }
 401                 clone = posix_acl_clone(acl, GFP_NOFS);
 402                 ret = -ENOMEM;
 403                 if (!clone)
 404                         goto cleanup;
 405
 406                 mode = inode->i_mode;
 407                 ret = posix_acl_create_masq(clone, &mode);
 408                 if (ret >= 0) {
 409                         ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 410                         if (ret2) {
 411                                 mlog_errno(ret2);
 412                                 ret = ret2;
 413                                 goto cleanup;
 414                         }
 415                         if (ret > 0) {
 416                                 ret = ocfs2_set_acl(handle, inode,
 417                                                     di_bh, ACL_TYPE_ACCESS,
 418                                                     clone, meta_ac, data_ac);
 419                         }
 420                 }
 421                 posix_acl_release(clone);
 422         }
 423 cleanup:
 424         posix_acl_release(acl);
 425         return ret;
 426 }
 427
 428 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 429                                           char *list,
 430                                           size_t list_len,
 431                                           const char *name,
 432                                           size_t name_len,
 433                                           int type)
 434 {
 435         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 436         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 437
 438         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 439                 return 0;
 440
 441         if (list && size <= list_len)
 442                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 443         return size;
 444 }
 445
 446 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 447                                            char *list,
 448                                            size_t list_len,
 449                                            const char *name,
 450                                            size_t name_len,
 451                                            int type)
 452 {
 453         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 454         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 455
 456         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 457                 return 0;
 458
 459         if (list && size <= list_len)
 460                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 461         return size;
 462 }
 463
 464 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 465                 void *buffer, size_t size, int type)
 466 {
 467         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 468         struct posix_acl *acl;
 469         int ret;
 470
 471         if (strcmp(name, "") != 0)
 472                 return -EINVAL;
 473         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 474                 return -EOPNOTSUPP;
 475
 476         acl = ocfs2_get_acl(dentry->d_inode, type);
 477         if (IS_ERR(acl))
 478                 return PTR_ERR(acl);
 479         if (acl == NULL)
 480                 return -ENODATA;
 481         ret = posix_acl_to_xattr(acl, buffer, size);
 482         posix_acl_release(acl);
 483
 484         return ret;
 485 }
 486
 487 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 488                 const void *value, size_t size, int flags, int type)
 489 {
 490         struct inode *inode = dentry->d_inode;
 491         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 492         struct posix_acl *acl;
 493         int ret = 0;
 494
 495         if (strcmp(name, "") != 0)
 496                 return -EINVAL;
 497         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 498                 return -EOPNOTSUPP;
 499
 500         if (!is_owner_or_cap(inode))
 501                 return -EPERM;
 502
 503         if (value) {
 504                 acl = posix_acl_from_xattr(value, size);
 505                 if (IS_ERR(acl))
 506                         return PTR_ERR(acl);
 507                 else if (acl) {
 508                         ret = posix_acl_valid(acl);
 509                         if (ret)
 510                                 goto cleanup;
 511                 }
 512         } else
 513                 acl = NULL;
 514
 515         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 516
 517 cleanup:
 518         posix_acl_release(acl);
 519         return ret;
 520 }
 521
 522 const struct xattr_handler ocfs2_xattr_acl_access_handler = {
 523         .prefix = POSIX_ACL_XATTR_ACCESS,
 524         .flags  = ACL_TYPE_ACCESS,
 525         .list   = ocfs2_xattr_list_acl_access,
 526         .get    = ocfs2_xattr_get_acl,
 527         .set    = ocfs2_xattr_set_acl,
 528 };
 529
 530 const struct xattr_handler ocfs2_xattr_acl_default_handler = {
 531         .prefix = POSIX_ACL_XATTR_DEFAULT,
 532         .flags  = ACL_TYPE_DEFAULT,
 533         .list   = ocfs2_xattr_list_acl_default,
 534         .get    = ocfs2_xattr_get_acl,
 535         .set    = ocfs2_xattr_set_acl,
 536 };