linux/fs/ocfs2/acl.c
<<
>>
Prefs
   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#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 */
  43static 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                switch(acl->a_entries[n].e_tag) {
  69                case ACL_USER:
  70                        acl->a_entries[n].e_uid =
  71                                make_kuid(&init_user_ns,
  72                                          le32_to_cpu(entry->e_id));
  73                        break;
  74                case ACL_GROUP:
  75                        acl->a_entries[n].e_gid =
  76                                make_kgid(&init_user_ns,
  77                                          le32_to_cpu(entry->e_id));
  78                        break;
  79                default:
  80                        break;
  81                }
  82                value += sizeof(struct posix_acl_entry);
  83
  84        }
  85        return acl;
  86}
  87
  88/*
  89 * Convert acl struct to xattr value.
  90 */
  91static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  92{
  93        struct ocfs2_acl_entry *entry = NULL;
  94        char *ocfs2_acl;
  95        size_t n;
  96
  97        *size = acl->a_count * sizeof(struct posix_acl_entry);
  98
  99        ocfs2_acl = kmalloc(*size, GFP_NOFS);
 100        if (!ocfs2_acl)
 101                return ERR_PTR(-ENOMEM);
 102
 103        entry = (struct ocfs2_acl_entry *)ocfs2_acl;
 104        for (n = 0; n < acl->a_count; n++, entry++) {
 105                entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
 106                entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
 107                switch(acl->a_entries[n].e_tag) {
 108                case ACL_USER:
 109                        entry->e_id = cpu_to_le32(
 110                                from_kuid(&init_user_ns,
 111                                          acl->a_entries[n].e_uid));
 112                        break;
 113                case ACL_GROUP:
 114                        entry->e_id = cpu_to_le32(
 115                                from_kgid(&init_user_ns,
 116                                          acl->a_entries[n].e_gid));
 117                        break;
 118                default:
 119                        entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 120                        break;
 121                }
 122        }
 123        return ocfs2_acl;
 124}
 125
 126static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 127                                              int type,
 128                                              struct buffer_head *di_bh)
 129{
 130        int name_index;
 131        char *value = NULL;
 132        struct posix_acl *acl;
 133        int retval;
 134
 135        switch (type) {
 136        case ACL_TYPE_ACCESS:
 137                name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 138                break;
 139        case ACL_TYPE_DEFAULT:
 140                name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 141                break;
 142        default:
 143                return ERR_PTR(-EINVAL);
 144        }
 145
 146        retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 147        if (retval > 0) {
 148                value = kmalloc(retval, GFP_NOFS);
 149                if (!value)
 150                        return ERR_PTR(-ENOMEM);
 151                retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 152                                                "", value, retval);
 153        }
 154
 155        if (retval > 0)
 156                acl = ocfs2_acl_from_xattr(value, retval);
 157        else if (retval == -ENODATA || retval == 0)
 158                acl = NULL;
 159        else
 160                acl = ERR_PTR(retval);
 161
 162        kfree(value);
 163
 164        return acl;
 165}
 166
 167
 168/*
 169 * Get posix acl.
 170 */
 171static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 172{
 173        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 174        struct buffer_head *di_bh = NULL;
 175        struct posix_acl *acl;
 176        int ret;
 177
 178        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 179                return NULL;
 180
 181        ret = ocfs2_inode_lock(inode, &di_bh, 0);
 182        if (ret < 0) {
 183                mlog_errno(ret);
 184                acl = ERR_PTR(ret);
 185                return acl;
 186        }
 187
 188        acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 189
 190        ocfs2_inode_unlock(inode, 0);
 191
 192        brelse(di_bh);
 193
 194        return acl;
 195}
 196
 197/*
 198 * Helper function to set i_mode in memory and disk. Some call paths
 199 * will not have di_bh or a journal handle to pass, in which case it
 200 * will create it's own.
 201 */
 202static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 203                              handle_t *handle, umode_t new_mode)
 204{
 205        int ret, commit_handle = 0;
 206        struct ocfs2_dinode *di;
 207
 208        if (di_bh == NULL) {
 209                ret = ocfs2_read_inode_block(inode, &di_bh);
 210                if (ret) {
 211                        mlog_errno(ret);
 212                        goto out;
 213                }
 214        } else
 215                get_bh(di_bh);
 216
 217        if (handle == NULL) {
 218                handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 219                                           OCFS2_INODE_UPDATE_CREDITS);
 220                if (IS_ERR(handle)) {
 221                        ret = PTR_ERR(handle);
 222                        mlog_errno(ret);
 223                        goto out_brelse;
 224                }
 225
 226                commit_handle = 1;
 227        }
 228
 229        di = (struct ocfs2_dinode *)di_bh->b_data;
 230        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 231                                      OCFS2_JOURNAL_ACCESS_WRITE);
 232        if (ret) {
 233                mlog_errno(ret);
 234                goto out_commit;
 235        }
 236
 237        inode->i_mode = new_mode;
 238        inode->i_ctime = CURRENT_TIME;
 239        di->i_mode = cpu_to_le16(inode->i_mode);
 240        di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 241        di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 242
 243        ocfs2_journal_dirty(handle, di_bh);
 244
 245out_commit:
 246        if (commit_handle)
 247                ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 248out_brelse:
 249        brelse(di_bh);
 250out:
 251        return ret;
 252}
 253
 254/*
 255 * Set the access or default ACL of an inode.
 256 */
 257static int ocfs2_set_acl(handle_t *handle,
 258                         struct inode *inode,
 259                         struct buffer_head *di_bh,
 260                         int type,
 261                         struct posix_acl *acl,
 262                         struct ocfs2_alloc_context *meta_ac,
 263                         struct ocfs2_alloc_context *data_ac)
 264{
 265        int name_index;
 266        void *value = NULL;
 267        size_t size = 0;
 268        int ret;
 269
 270        if (S_ISLNK(inode->i_mode))
 271                return -EOPNOTSUPP;
 272
 273        switch (type) {
 274        case ACL_TYPE_ACCESS:
 275                name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 276                if (acl) {
 277                        umode_t mode = inode->i_mode;
 278                        ret = posix_acl_equiv_mode(acl, &mode);
 279                        if (ret < 0)
 280                                return ret;
 281                        else {
 282                                if (ret == 0)
 283                                        acl = NULL;
 284
 285                                ret = ocfs2_acl_set_mode(inode, di_bh,
 286                                                         handle, mode);
 287                                if (ret)
 288                                        return ret;
 289
 290                        }
 291                }
 292                break;
 293        case ACL_TYPE_DEFAULT:
 294                name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 295                if (!S_ISDIR(inode->i_mode))
 296                        return acl ? -EACCES : 0;
 297                break;
 298        default:
 299                return -EINVAL;
 300        }
 301
 302        if (acl) {
 303                value = ocfs2_acl_to_xattr(acl, &size);
 304                if (IS_ERR(value))
 305                        return (int)PTR_ERR(value);
 306        }
 307
 308        if (handle)
 309                ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 310                                             "", value, size, 0,
 311                                             meta_ac, data_ac);
 312        else
 313                ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 314
 315        kfree(value);
 316
 317        return ret;
 318}
 319
 320struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
 321{
 322        struct ocfs2_super *osb;
 323        struct buffer_head *di_bh = NULL;
 324        struct posix_acl *acl;
 325        int ret = -EAGAIN;
 326
 327        osb = OCFS2_SB(inode->i_sb);
 328        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 329                return NULL;
 330
 331        ret = ocfs2_read_inode_block(inode, &di_bh);
 332        if (ret < 0)
 333                return ERR_PTR(ret);
 334
 335        acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 336
 337        brelse(di_bh);
 338
 339        return acl;
 340}
 341
 342int ocfs2_acl_chmod(struct inode *inode)
 343{
 344        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 345        struct posix_acl *acl;
 346        int ret;
 347
 348        if (S_ISLNK(inode->i_mode))
 349                return -EOPNOTSUPP;
 350
 351        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 352                return 0;
 353
 354        acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 355        if (IS_ERR(acl) || !acl)
 356                return PTR_ERR(acl);
 357        ret = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
 358        if (ret)
 359                return ret;
 360        ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 361                            acl, NULL, NULL);
 362        posix_acl_release(acl);
 363        return ret;
 364}
 365
 366/*
 367 * Initialize the ACLs of a new inode. If parent directory has default ACL,
 368 * then clone to new inode. Called from ocfs2_mknod.
 369 */
 370int ocfs2_init_acl(handle_t *handle,
 371                   struct inode *inode,
 372                   struct inode *dir,
 373                   struct buffer_head *di_bh,
 374                   struct buffer_head *dir_bh,
 375                   struct ocfs2_alloc_context *meta_ac,
 376                   struct ocfs2_alloc_context *data_ac)
 377{
 378        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 379        struct posix_acl *acl = NULL;
 380        int ret = 0, ret2;
 381        umode_t mode;
 382
 383        if (!S_ISLNK(inode->i_mode)) {
 384                if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 385                        acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 386                                                   dir_bh);
 387                        if (IS_ERR(acl))
 388                                return PTR_ERR(acl);
 389                }
 390                if (!acl) {
 391                        mode = inode->i_mode & ~current_umask();
 392                        ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 393                        if (ret) {
 394                                mlog_errno(ret);
 395                                goto cleanup;
 396                        }
 397                }
 398        }
 399        if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 400                if (S_ISDIR(inode->i_mode)) {
 401                        ret = ocfs2_set_acl(handle, inode, di_bh,
 402                                            ACL_TYPE_DEFAULT, acl,
 403                                            meta_ac, data_ac);
 404                        if (ret)
 405                                goto cleanup;
 406                }
 407                mode = inode->i_mode;
 408                ret = posix_acl_create(&acl, GFP_NOFS, &mode);
 409                if (ret < 0)
 410                        return ret;
 411
 412                ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 413                if (ret2) {
 414                        mlog_errno(ret2);
 415                        ret = ret2;
 416                        goto cleanup;
 417                }
 418                if (ret > 0) {
 419                        ret = ocfs2_set_acl(handle, inode,
 420                                            di_bh, ACL_TYPE_ACCESS,
 421                                            acl, meta_ac, data_ac);
 422                }
 423        }
 424cleanup:
 425        posix_acl_release(acl);
 426        return ret;
 427}
 428
 429static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 430                                          char *list,
 431                                          size_t list_len,
 432                                          const char *name,
 433                                          size_t name_len,
 434                                          int type)
 435{
 436        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 437        const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 438
 439        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 440                return 0;
 441
 442        if (list && size <= list_len)
 443                memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 444        return size;
 445}
 446
 447static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 448                                           char *list,
 449                                           size_t list_len,
 450                                           const char *name,
 451                                           size_t name_len,
 452                                           int type)
 453{
 454        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 455        const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 456
 457        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 458                return 0;
 459
 460        if (list && size <= list_len)
 461                memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 462        return size;
 463}
 464
 465static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 466                void *buffer, size_t size, int type)
 467{
 468        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 469        struct posix_acl *acl;
 470        int ret;
 471
 472        if (strcmp(name, "") != 0)
 473                return -EINVAL;
 474        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 475                return -EOPNOTSUPP;
 476
 477        acl = ocfs2_get_acl(dentry->d_inode, type);
 478        if (IS_ERR(acl))
 479                return PTR_ERR(acl);
 480        if (acl == NULL)
 481                return -ENODATA;
 482        ret = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
 483        posix_acl_release(acl);
 484
 485        return ret;
 486}
 487
 488static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 489                const void *value, size_t size, int flags, int type)
 490{
 491        struct inode *inode = dentry->d_inode;
 492        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 493        struct posix_acl *acl;
 494        int ret = 0;
 495
 496        if (strcmp(name, "") != 0)
 497                return -EINVAL;
 498        if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 499                return -EOPNOTSUPP;
 500
 501        if (!inode_owner_or_capable(inode))
 502                return -EPERM;
 503
 504        if (value) {
 505                acl = posix_acl_from_xattr(&init_user_ns, value, size);
 506                if (IS_ERR(acl))
 507                        return PTR_ERR(acl);
 508                else if (acl) {
 509                        ret = posix_acl_valid(acl);
 510                        if (ret)
 511                                goto cleanup;
 512                }
 513        } else
 514                acl = NULL;
 515
 516        ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 517
 518cleanup:
 519        posix_acl_release(acl);
 520        return ret;
 521}
 522
 523const struct xattr_handler ocfs2_xattr_acl_access_handler = {
 524        .prefix = POSIX_ACL_XATTR_ACCESS,
 525        .flags  = ACL_TYPE_ACCESS,
 526        .list   = ocfs2_xattr_list_acl_access,
 527        .get    = ocfs2_xattr_get_acl,
 528        .set    = ocfs2_xattr_set_acl,
 529};
 530
 531const struct xattr_handler ocfs2_xattr_acl_default_handler = {
 532        .prefix = POSIX_ACL_XATTR_DEFAULT,
 533        .flags  = ACL_TYPE_DEFAULT,
 534        .list   = ocfs2_xattr_list_acl_default,
 535        .get    = ocfs2_xattr_get_acl,
 536        .set    = ocfs2_xattr_set_acl,
 537};
 538
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.