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         int name_index;
 104         char *value = NULL;
 105         struct posix_acl *acl;
 106         int retval;
 107
 108         switch (type) {
 109         case ACL_TYPE_ACCESS:
 110                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 111                 break;
 112         case ACL_TYPE_DEFAULT:
 113                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 114                 break;
 115         default:
 116                 return ERR_PTR(-EINVAL);
 117         }
 118
 119         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 120         if (retval > 0) {
 121                 value = kmalloc(retval, GFP_NOFS);
 122                 if (!value)
 123                         return ERR_PTR(-ENOMEM);
 124                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 125                                                 "", value, retval);
 126         }
 127
 128         if (retval > 0)
 129                 acl = ocfs2_acl_from_xattr(value, retval);
 130         else if (retval == -ENODATA || retval == 0)
 131                 acl = NULL;
 132         else
 133                 acl = ERR_PTR(retval);
 134
 135         kfree(value);
 136
 137         return acl;
 138 }
 139
 140
 141 /*
 142  * Get posix acl.
 143  */
 144 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 145 {
 146         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 147         struct buffer_head *di_bh = NULL;
 148         struct posix_acl *acl;
 149         int ret;
 150
 151         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 152                 return NULL;
 153
 154         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 155         if (ret < 0) {
 156                 mlog_errno(ret);
 157                 acl = ERR_PTR(ret);
 158                 return acl;
 159         }
 160
 161         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 162
 163         ocfs2_inode_unlock(inode, 0);
 164
 165         brelse(di_bh);
 166
 167         return acl;
 168 }
 169
 170 /*
 171  * Helper function to set i_mode in memory and disk. Some call paths
 172  * will not have di_bh or a journal handle to pass, in which case it
 173  * will create it's own.
 174  */
 175 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 176                               handle_t *handle, umode_t new_mode)
 177 {
 178         int ret, commit_handle = 0;
 179         struct ocfs2_dinode *di;
 180
 181         if (di_bh == NULL) {
 182                 ret = ocfs2_read_inode_block(inode, &di_bh);
 183                 if (ret) {
 184                         mlog_errno(ret);
 185                         goto out;
 186                 }
 187         } else
 188                 get_bh(di_bh);
 189
 190         if (handle == NULL) {
 191                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 192                                            OCFS2_INODE_UPDATE_CREDITS);
 193                 if (IS_ERR(handle)) {
 194                         ret = PTR_ERR(handle);
 195                         mlog_errno(ret);
 196                         goto out_brelse;
 197                 }
 198
 199                 commit_handle = 1;
 200         }
 201
 202         di = (struct ocfs2_dinode *)di_bh->b_data;
 203         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 204                                       OCFS2_JOURNAL_ACCESS_WRITE);
 205         if (ret) {
 206                 mlog_errno(ret);
 207                 goto out_commit;
 208         }
 209
 210         inode->i_mode = new_mode;
 211         di->i_mode = cpu_to_le16(inode->i_mode);
 212
 213         ocfs2_journal_dirty(handle, di_bh);
 214
 215 out_commit:
 216         if (commit_handle)
 217                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 218 out_brelse:
 219         brelse(di_bh);
 220 out:
 221         return ret;
 222 }
 223
 224 /*
 225  * Set the access or default ACL of an inode.
 226  */
 227 static int ocfs2_set_acl(handle_t *handle,
 228                          struct inode *inode,
 229                          struct buffer_head *di_bh,
 230                          int type,
 231                          struct posix_acl *acl,
 232                          struct ocfs2_alloc_context *meta_ac,
 233                          struct ocfs2_alloc_context *data_ac)
 234 {
 235         int name_index;
 236         void *value = NULL;
 237         size_t size = 0;
 238         int ret;
 239
 240         if (S_ISLNK(inode->i_mode))
 241                 return -EOPNOTSUPP;
 242
 243         switch (type) {
 244         case ACL_TYPE_ACCESS:
 245                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 246                 if (acl) {
 247                         mode_t mode = inode->i_mode;
 248                         ret = posix_acl_equiv_mode(acl, &mode);
 249                         if (ret < 0)
 250                                 return ret;
 251                         else {
 252                                 if (ret == 0)
 253                                         acl = NULL;
 254
 255                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 256                                                          handle, mode);
 257                                 if (ret)
 258                                         return ret;
 259
 260                         }
 261                 }
 262                 break;
 263         case ACL_TYPE_DEFAULT:
 264                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 265                 if (!S_ISDIR(inode->i_mode))
 266                         return acl ? -EACCES : 0;
 267                 break;
 268         default:
 269                 return -EINVAL;
 270         }
 271
 272         if (acl) {
 273                 value = ocfs2_acl_to_xattr(acl, &size);
 274                 if (IS_ERR(value))
 275                         return (int)PTR_ERR(value);
 276         }
 277
 278         if (handle)
 279                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 280                                              "", value, size, 0,
 281                                              meta_ac, data_ac);
 282         else
 283                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 284
 285         kfree(value);
 286
 287         return ret;
 288 }
 289
 290 int ocfs2_check_acl(struct inode *inode, int mask)
 291 {
 292         struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 293
 294         if (IS_ERR(acl))
 295                 return PTR_ERR(acl);
 296         if (acl) {
 297                 int ret = posix_acl_permission(inode, acl, mask);
 298                 posix_acl_release(acl);
 299                 return ret;
 300         }
 301
 302         return -EAGAIN;
 303 }
 304
 305 int ocfs2_acl_chmod(struct inode *inode)
 306 {
 307         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 308         struct posix_acl *acl, *clone;
 309         int ret;
 310
 311         if (S_ISLNK(inode->i_mode))
 312                 return -EOPNOTSUPP;
 313
 314         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 315                 return 0;
 316
 317         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 318         if (IS_ERR(acl) || !acl)
 319                 return PTR_ERR(acl);
 320         clone = posix_acl_clone(acl, GFP_KERNEL);
 321         posix_acl_release(acl);
 322         if (!clone)
 323                 return -ENOMEM;
 324         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 325         if (!ret)
 326                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 327                                     clone, NULL, NULL);
 328         posix_acl_release(clone);
 329         return ret;
 330 }
 331
 332 /*
 333  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 334  * then clone to new inode. Called from ocfs2_mknod.
 335  */
 336 int ocfs2_init_acl(handle_t *handle,
 337                    struct inode *inode,
 338                    struct inode *dir,
 339                    struct buffer_head *di_bh,
 340                    struct buffer_head *dir_bh,
 341                    struct ocfs2_alloc_context *meta_ac,
 342                    struct ocfs2_alloc_context *data_ac)
 343 {
 344         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 345         struct posix_acl *acl = NULL;
 346         int ret = 0;
 347         mode_t mode;
 348
 349         if (!S_ISLNK(inode->i_mode)) {
 350                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 351                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 352                                                    dir_bh);
 353                         if (IS_ERR(acl))
 354                                 return PTR_ERR(acl);
 355                 }
 356                 if (!acl) {
 357                         mode = inode->i_mode & ~current_umask();
 358                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 359                         if (ret) {
 360                                 mlog_errno(ret);
 361                                 goto cleanup;
 362                         }
 363                 }
 364         }
 365         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 366                 struct posix_acl *clone;
 367
 368                 if (S_ISDIR(inode->i_mode)) {
 369                         ret = ocfs2_set_acl(handle, inode, di_bh,
 370                                             ACL_TYPE_DEFAULT, acl,
 371                                             meta_ac, data_ac);
 372                         if (ret)
 373                                 goto cleanup;
 374                 }
 375                 clone = posix_acl_clone(acl, GFP_NOFS);
 376                 ret = -ENOMEM;
 377                 if (!clone)
 378                         goto cleanup;
 379
 380                 mode = inode->i_mode;
 381                 ret = posix_acl_create_masq(clone, &mode);
 382                 if (ret >= 0) {
 383                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 384                         if (ret > 0) {
 385                                 ret = ocfs2_set_acl(handle, inode,
 386                                                     di_bh, ACL_TYPE_ACCESS,
 387                                                     clone, meta_ac, data_ac);
 388                         }
 389                 }
 390                 posix_acl_release(clone);
 391         }
 392 cleanup:
 393         posix_acl_release(acl);
 394         return ret;
 395 }
 396
 397 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 398                                           char *list,
 399                                           size_t list_len,
 400                                           const char *name,
 401                                           size_t name_len,
 402                                           int type)
 403 {
 404         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 405         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 406
 407         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 408                 return 0;
 409
 410         if (list && size <= list_len)
 411                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 412         return size;
 413 }
 414
 415 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 416                                            char *list,
 417                                            size_t list_len,
 418                                            const char *name,
 419                                            size_t name_len,
 420                                            int type)
 421 {
 422         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 423         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 424
 425         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 426                 return 0;
 427
 428         if (list && size <= list_len)
 429                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 430         return size;
 431 }
 432
 433 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 434                 void *buffer, size_t size, int type)
 435 {
 436         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 437         struct posix_acl *acl;
 438         int ret;
 439
 440         if (strcmp(name, "") != 0)
 441                 return -EINVAL;
 442         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 443                 return -EOPNOTSUPP;
 444
 445         acl = ocfs2_get_acl(dentry->d_inode, type);
 446         if (IS_ERR(acl))
 447                 return PTR_ERR(acl);
 448         if (acl == NULL)
 449                 return -ENODATA;
 450         ret = posix_acl_to_xattr(acl, buffer, size);
 451         posix_acl_release(acl);
 452
 453         return ret;
 454 }
 455
 456 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 457                 const void *value, size_t size, int flags, int type)
 458 {
 459         struct inode *inode = dentry->d_inode;
 460         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 461         struct posix_acl *acl;
 462         int ret = 0;
 463
 464         if (strcmp(name, "") != 0)
 465                 return -EINVAL;
 466         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 467                 return -EOPNOTSUPP;
 468
 469         if (!is_owner_or_cap(inode))
 470                 return -EPERM;
 471
 472         if (value) {
 473                 acl = posix_acl_from_xattr(value, size);
 474                 if (IS_ERR(acl))
 475                         return PTR_ERR(acl);
 476                 else if (acl) {
 477                         ret = posix_acl_valid(acl);
 478                         if (ret)
 479                                 goto cleanup;
 480                 }
 481         } else
 482                 acl = NULL;
 483
 484         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 485
 486 cleanup:
 487         posix_acl_release(acl);
 488         return ret;
 489 }
 490
 491 struct xattr_handler ocfs2_xattr_acl_access_handler = {
 492         .prefix = POSIX_ACL_XATTR_ACCESS,
 493         .flags  = ACL_TYPE_ACCESS,
 494         .list   = ocfs2_xattr_list_acl_access,
 495         .get    = ocfs2_xattr_get_acl,
 496         .set    = ocfs2_xattr_set_acl,
 497 };
 498
 499 struct xattr_handler ocfs2_xattr_acl_default_handler = {
 500         .prefix = POSIX_ACL_XATTR_DEFAULT,
 501         .flags  = ACL_TYPE_DEFAULT,
 502         .list   = ocfs2_xattr_list_acl_default,
 503         .get    = ocfs2_xattr_get_acl,
 504         .set    = ocfs2_xattr_set_acl,
 505 };