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         di->i_mode = cpu_to_le16(inode->i_mode);
 213
 214         ocfs2_journal_dirty(handle, di_bh);
 215
 216 out_commit:
 217         if (commit_handle)
 218                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 219 out_brelse:
 220         brelse(di_bh);
 221 out:
 222         return ret;
 223 }
 224
 225 /*
 226  * Set the access or default ACL of an inode.
 227  */
 228 static int ocfs2_set_acl(handle_t *handle,
 229                          struct inode *inode,
 230                          struct buffer_head *di_bh,
 231                          int type,
 232                          struct posix_acl *acl,
 233                          struct ocfs2_alloc_context *meta_ac,
 234                          struct ocfs2_alloc_context *data_ac)
 235 {
 236         int name_index;
 237         void *value = NULL;
 238         size_t size = 0;
 239         int ret;
 240
 241         if (S_ISLNK(inode->i_mode))
 242                 return -EOPNOTSUPP;
 243
 244         switch (type) {
 245         case ACL_TYPE_ACCESS:
 246                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 247                 if (acl) {
 248                         mode_t mode = inode->i_mode;
 249                         ret = posix_acl_equiv_mode(acl, &mode);
 250                         if (ret < 0)
 251                                 return ret;
 252                         else {
 253                                 if (ret == 0)
 254                                         acl = NULL;
 255
 256                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 257                                                          handle, mode);
 258                                 if (ret)
 259                                         return ret;
 260
 261                         }
 262                 }
 263                 break;
 264         case ACL_TYPE_DEFAULT:
 265                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 266                 if (!S_ISDIR(inode->i_mode))
 267                         return acl ? -EACCES : 0;
 268                 break;
 269         default:
 270                 return -EINVAL;
 271         }
 272
 273         if (acl) {
 274                 value = ocfs2_acl_to_xattr(acl, &size);
 275                 if (IS_ERR(value))
 276                         return (int)PTR_ERR(value);
 277         }
 278
 279         if (handle)
 280                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 281                                              "", value, size, 0,
 282                                              meta_ac, data_ac);
 283         else
 284                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 285
 286         kfree(value);
 287
 288         return ret;
 289 }
 290
 291 int ocfs2_check_acl(struct inode *inode, int mask)
 292 {
 293         struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 294
 295         if (IS_ERR(acl))
 296                 return PTR_ERR(acl);
 297         if (acl) {
 298                 int ret = posix_acl_permission(inode, acl, mask);
 299                 posix_acl_release(acl);
 300                 return ret;
 301         }
 302
 303         return -EAGAIN;
 304 }
 305
 306 int ocfs2_acl_chmod(struct inode *inode)
 307 {
 308         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 309         struct posix_acl *acl, *clone;
 310         int ret;
 311
 312         if (S_ISLNK(inode->i_mode))
 313                 return -EOPNOTSUPP;
 314
 315         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 316                 return 0;
 317
 318         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 319         if (IS_ERR(acl) || !acl)
 320                 return PTR_ERR(acl);
 321         clone = posix_acl_clone(acl, GFP_KERNEL);
 322         posix_acl_release(acl);
 323         if (!clone)
 324                 return -ENOMEM;
 325         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 326         if (!ret)
 327                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 328                                     clone, NULL, NULL);
 329         posix_acl_release(clone);
 330         return ret;
 331 }
 332
 333 /*
 334  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 335  * then clone to new inode. Called from ocfs2_mknod.
 336  */
 337 int ocfs2_init_acl(handle_t *handle,
 338                    struct inode *inode,
 339                    struct inode *dir,
 340                    struct buffer_head *di_bh,
 341                    struct buffer_head *dir_bh,
 342                    struct ocfs2_alloc_context *meta_ac,
 343                    struct ocfs2_alloc_context *data_ac)
 344 {
 345         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 346         struct posix_acl *acl = NULL;
 347         int ret = 0, ret2;
 348         mode_t mode;
 349
 350         if (!S_ISLNK(inode->i_mode)) {
 351                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 352                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 353                                                    dir_bh);
 354                         if (IS_ERR(acl))
 355                                 return PTR_ERR(acl);
 356                 }
 357                 if (!acl) {
 358                         mode = inode->i_mode & ~current_umask();
 359                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 360                         if (ret) {
 361                                 mlog_errno(ret);
 362                                 goto cleanup;
 363                         }
 364                 }
 365         }
 366         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 367                 struct posix_acl *clone;
 368
 369                 if (S_ISDIR(inode->i_mode)) {
 370                         ret = ocfs2_set_acl(handle, inode, di_bh,
 371                                             ACL_TYPE_DEFAULT, acl,
 372                                             meta_ac, data_ac);
 373                         if (ret)
 374                                 goto cleanup;
 375                 }
 376                 clone = posix_acl_clone(acl, GFP_NOFS);
 377                 ret = -ENOMEM;
 378                 if (!clone)
 379                         goto cleanup;
 380
 381                 mode = inode->i_mode;
 382                 ret = posix_acl_create_masq(clone, &mode);
 383                 if (ret >= 0) {
 384                         ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 385                         if (ret2) {
 386                                 mlog_errno(ret2);
 387                                 ret = ret2;
 388                                 goto cleanup;
 389                         }
 390                         if (ret > 0) {
 391                                 ret = ocfs2_set_acl(handle, inode,
 392                                                     di_bh, ACL_TYPE_ACCESS,
 393                                                     clone, meta_ac, data_ac);
 394                         }
 395                 }
 396                 posix_acl_release(clone);
 397         }
 398 cleanup:
 399         posix_acl_release(acl);
 400         return ret;
 401 }
 402
 403 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 404                                           char *list,
 405                                           size_t list_len,
 406                                           const char *name,
 407                                           size_t name_len,
 408                                           int type)
 409 {
 410         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 411         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 412
 413         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 414                 return 0;
 415
 416         if (list && size <= list_len)
 417                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 418         return size;
 419 }
 420
 421 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 422                                            char *list,
 423                                            size_t list_len,
 424                                            const char *name,
 425                                            size_t name_len,
 426                                            int type)
 427 {
 428         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 429         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 430
 431         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 432                 return 0;
 433
 434         if (list && size <= list_len)
 435                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 436         return size;
 437 }
 438
 439 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 440                 void *buffer, size_t size, int type)
 441 {
 442         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 443         struct posix_acl *acl;
 444         int ret;
 445
 446         if (strcmp(name, "") != 0)
 447                 return -EINVAL;
 448         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 449                 return -EOPNOTSUPP;
 450
 451         acl = ocfs2_get_acl(dentry->d_inode, type);
 452         if (IS_ERR(acl))
 453                 return PTR_ERR(acl);
 454         if (acl == NULL)
 455                 return -ENODATA;
 456         ret = posix_acl_to_xattr(acl, buffer, size);
 457         posix_acl_release(acl);
 458
 459         return ret;
 460 }
 461
 462 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 463                 const void *value, size_t size, int flags, int type)
 464 {
 465         struct inode *inode = dentry->d_inode;
 466         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 467         struct posix_acl *acl;
 468         int ret = 0;
 469
 470         if (strcmp(name, "") != 0)
 471                 return -EINVAL;
 472         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 473                 return -EOPNOTSUPP;
 474
 475         if (!is_owner_or_cap(inode))
 476                 return -EPERM;
 477
 478         if (value) {
 479                 acl = posix_acl_from_xattr(value, size);
 480                 if (IS_ERR(acl))
 481                         return PTR_ERR(acl);
 482                 else if (acl) {
 483                         ret = posix_acl_valid(acl);
 484                         if (ret)
 485                                 goto cleanup;
 486                 }
 487         } else
 488                 acl = NULL;
 489
 490         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 491
 492 cleanup:
 493         posix_acl_release(acl);
 494         return ret;
 495 }
 496
 497 const struct xattr_handler ocfs2_xattr_acl_access_handler = {
 498         .prefix = POSIX_ACL_XATTR_ACCESS,
 499         .flags  = ACL_TYPE_ACCESS,
 500         .list   = ocfs2_xattr_list_acl_access,
 501         .get    = ocfs2_xattr_get_acl,
 502         .set    = ocfs2_xattr_set_acl,
 503 };
 504
 505 const struct xattr_handler ocfs2_xattr_acl_default_handler = {
 506         .prefix = POSIX_ACL_XATTR_DEFAULT,
 507         .flags  = ACL_TYPE_DEFAULT,
 508         .list   = ocfs2_xattr_list_acl_default,
 509         .get    = ocfs2_xattr_get_acl,
 510         .set    = ocfs2_xattr_set_acl,
 511 };