linux/fs/ocfs2/acl.c
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   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 */
  41static 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 */
  76static 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
  97static 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 */
 146static 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 */
 175static 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
 233int 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
 248int 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 */
 279int 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        }
 329cleanup:
 330        posix_acl_release(acl);
 331        return ret;
 332}
 333
 334static 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
 351static 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
 368static 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
 391static 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
 401static 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
 411static 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
 440cleanup:
 441        posix_acl_release(acl);
 442        return ret;
 443}
 444
 445static 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
 456static 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
 467struct 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
 474struct 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};
 480