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 #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
  55         acl = posix_acl_alloc(count, GFP_NOFS);
  56         if (!acl)
  57                 return ERR_PTR(-ENOMEM);
  58         for (n = 0; n < count; n++) {
  59                 struct ocfs2_acl_entry *entry =
  60                         (struct ocfs2_acl_entry *)value;
  61
  62                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  63                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  64                 switch(acl->a_entries[n].e_tag) {
  65                 case ACL_USER:
  66                         acl->a_entries[n].e_uid =
  67                                 make_kuid(&init_user_ns,
  68                                           le32_to_cpu(entry->e_id));
  69                         break;
  70                 case ACL_GROUP:
  71                         acl->a_entries[n].e_gid =
  72                                 make_kgid(&init_user_ns,
  73                                           le32_to_cpu(entry->e_id));
  74                         break;
  75                 default:
  76                         break;
  77                 }
  78                 value += sizeof(struct posix_acl_entry);
  79
  80         }
  81         return acl;
  82 }
  83
  84 /*
  85  * Convert acl struct to xattr value.
  86  */
  87 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  88 {
  89         struct ocfs2_acl_entry *entry = NULL;
  90         char *ocfs2_acl;
  91         size_t n;
  92
  93         *size = acl->a_count * sizeof(struct posix_acl_entry);
  94
  95         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  96         if (!ocfs2_acl)
  97                 return ERR_PTR(-ENOMEM);
  98
  99         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
 100         for (n = 0; n < acl->a_count; n++, entry++) {
 101                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
 102                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
 103                 switch(acl->a_entries[n].e_tag) {
 104                 case ACL_USER:
 105                         entry->e_id = cpu_to_le32(
 106                                 from_kuid(&init_user_ns,
 107                                           acl->a_entries[n].e_uid));
 108                         break;
 109                 case ACL_GROUP:
 110                         entry->e_id = cpu_to_le32(
 111                                 from_kgid(&init_user_ns,
 112                                           acl->a_entries[n].e_gid));
 113                         break;
 114                 default:
 115                         entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 116                         break;
 117                 }
 118         }
 119         return ocfs2_acl;
 120 }
 121
 122 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 123                                               int type,
 124                                               struct buffer_head *di_bh)
 125 {
 126         int name_index;
 127         char *value = NULL;
 128         struct posix_acl *acl;
 129         int retval;
 130
 131         switch (type) {
 132         case ACL_TYPE_ACCESS:
 133                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 134                 break;
 135         case ACL_TYPE_DEFAULT:
 136                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 137                 break;
 138         default:
 139                 return ERR_PTR(-EINVAL);
 140         }
 141
 142         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 143         if (retval > 0) {
 144                 value = kmalloc(retval, GFP_NOFS);
 145                 if (!value)
 146                         return ERR_PTR(-ENOMEM);
 147                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 148                                                 "", value, retval);
 149         }
 150
 151         if (retval > 0)
 152                 acl = ocfs2_acl_from_xattr(value, retval);
 153         else if (retval == -ENODATA || retval == 0)
 154                 acl = NULL;
 155         else
 156                 acl = ERR_PTR(retval);
 157
 158         kfree(value);
 159
 160         return acl;
 161 }
 162
 163
 164 /*
 165  * Get posix acl.
 166  */
 167 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 168 {
 169         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 170         struct buffer_head *di_bh = NULL;
 171         struct posix_acl *acl;
 172         int ret;
 173
 174         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 175                 return NULL;
 176
 177         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 178         if (ret < 0) {
 179                 mlog_errno(ret);
 180                 acl = ERR_PTR(ret);
 181                 return acl;
 182         }
 183
 184         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 185
 186         ocfs2_inode_unlock(inode, 0);
 187
 188         brelse(di_bh);
 189
 190         return acl;
 191 }
 192
 193 /*
 194  * Helper function to set i_mode in memory and disk. Some call paths
 195  * will not have di_bh or a journal handle to pass, in which case it
 196  * will create it's own.
 197  */
 198 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 199                               handle_t *handle, umode_t new_mode)
 200 {
 201         int ret, commit_handle = 0;
 202         struct ocfs2_dinode *di;
 203
 204         if (di_bh == NULL) {
 205                 ret = ocfs2_read_inode_block(inode, &di_bh);
 206                 if (ret) {
 207                         mlog_errno(ret);
 208                         goto out;
 209                 }
 210         } else
 211                 get_bh(di_bh);
 212
 213         if (handle == NULL) {
 214                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 215                                            OCFS2_INODE_UPDATE_CREDITS);
 216                 if (IS_ERR(handle)) {
 217                         ret = PTR_ERR(handle);
 218                         mlog_errno(ret);
 219                         goto out_brelse;
 220                 }
 221
 222                 commit_handle = 1;
 223         }
 224
 225         di = (struct ocfs2_dinode *)di_bh->b_data;
 226         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 227                                       OCFS2_JOURNAL_ACCESS_WRITE);
 228         if (ret) {
 229                 mlog_errno(ret);
 230                 goto out_commit;
 231         }
 232
 233         inode->i_mode = new_mode;
 234         inode->i_ctime = CURRENT_TIME;
 235         di->i_mode = cpu_to_le16(inode->i_mode);
 236         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 237         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 238
 239         ocfs2_journal_dirty(handle, di_bh);
 240
 241 out_commit:
 242         if (commit_handle)
 243                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 244 out_brelse:
 245         brelse(di_bh);
 246 out:
 247         return ret;
 248 }
 249
 250 /*
 251  * Set the access or default ACL of an inode.
 252  */
 253 static int ocfs2_set_acl(handle_t *handle,
 254                          struct inode *inode,
 255                          struct buffer_head *di_bh,
 256                          int type,
 257                          struct posix_acl *acl,
 258                          struct ocfs2_alloc_context *meta_ac,
 259                          struct ocfs2_alloc_context *data_ac)
 260 {
 261         int name_index;
 262         void *value = NULL;
 263         size_t size = 0;
 264         int ret;
 265
 266         if (S_ISLNK(inode->i_mode))
 267                 return -EOPNOTSUPP;
 268
 269         switch (type) {
 270         case ACL_TYPE_ACCESS:
 271                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 272                 if (acl) {
 273                         umode_t mode = inode->i_mode;
 274                         ret = posix_acl_equiv_mode(acl, &mode);
 275                         if (ret < 0)
 276                                 return ret;
 277                         else {
 278                                 if (ret == 0)
 279                                         acl = NULL;
 280
 281                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 282                                                          handle, mode);
 283                                 if (ret)
 284                                         return ret;
 285
 286                         }
 287                 }
 288                 break;
 289         case ACL_TYPE_DEFAULT:
 290                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 291                 if (!S_ISDIR(inode->i_mode))
 292                         return acl ? -EACCES : 0;
 293                 break;
 294         default:
 295                 return -EINVAL;
 296         }
 297
 298         if (acl) {
 299                 value = ocfs2_acl_to_xattr(acl, &size);
 300                 if (IS_ERR(value))
 301                         return (int)PTR_ERR(value);
 302         }
 303
 304         if (handle)
 305                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 306                                              "", value, size, 0,
 307                                              meta_ac, data_ac);
 308         else
 309                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 310
 311         kfree(value);
 312
 313         return ret;
 314 }
 315
 316 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
 317 {
 318         struct ocfs2_super *osb;
 319         struct buffer_head *di_bh = NULL;
 320         struct posix_acl *acl;
 321         int ret = -EAGAIN;
 322
 323         osb = OCFS2_SB(inode->i_sb);
 324         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 325                 return NULL;
 326
 327         ret = ocfs2_read_inode_block(inode, &di_bh);
 328         if (ret < 0)
 329                 return ERR_PTR(ret);
 330
 331         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 332
 333         brelse(di_bh);
 334
 335         return acl;
 336 }
 337
 338 int ocfs2_acl_chmod(struct inode *inode)
 339 {
 340         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 341         struct posix_acl *acl;
 342         int ret;
 343
 344         if (S_ISLNK(inode->i_mode))
 345                 return -EOPNOTSUPP;
 346
 347         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 348                 return 0;
 349
 350         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 351         if (IS_ERR(acl) || !acl)
 352                 return PTR_ERR(acl);
 353         ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
 354         if (ret)
 355                 return ret;
 356         ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 357                             acl, NULL, NULL);
 358         posix_acl_release(acl);
 359         return ret;
 360 }
 361
 362 /*
 363  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 364  * then clone to new inode. Called from ocfs2_mknod.
 365  */
 366 int ocfs2_init_acl(handle_t *handle,
 367                    struct inode *inode,
 368                    struct inode *dir,
 369                    struct buffer_head *di_bh,
 370                    struct buffer_head *dir_bh,
 371                    struct ocfs2_alloc_context *meta_ac,
 372                    struct ocfs2_alloc_context *data_ac)
 373 {
 374         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 375         struct posix_acl *acl = NULL;
 376         int ret = 0, ret2;
 377         umode_t mode;
 378
 379         if (!S_ISLNK(inode->i_mode)) {
 380                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 381                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 382                                                    dir_bh);
 383                         if (IS_ERR(acl))
 384                                 return PTR_ERR(acl);
 385                 }
 386                 if (!acl) {
 387                         mode = inode->i_mode & ~current_umask();
 388                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 389                         if (ret) {
 390                                 mlog_errno(ret);
 391                                 goto cleanup;
 392                         }
 393                 }
 394         }
 395         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 396                 if (S_ISDIR(inode->i_mode)) {
 397                         ret = ocfs2_set_acl(handle, inode, di_bh,
 398                                             ACL_TYPE_DEFAULT, acl,
 399                                             meta_ac, data_ac);
 400                         if (ret)
 401                                 goto cleanup;
 402                 }
 403                 mode = inode->i_mode;
 404                 ret = posix_acl_create(&acl, GFP_NOFS, &mode);
 405                 if (ret < 0)
 406                         return ret;
 407
 408                 ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 409                 if (ret2) {
 410                         mlog_errno(ret2);
 411                         ret = ret2;
 412                         goto cleanup;
 413                 }
 414                 if (ret > 0) {
 415                         ret = ocfs2_set_acl(handle, inode,
 416                                             di_bh, ACL_TYPE_ACCESS,
 417                                             acl, meta_ac, data_ac);
 418                 }
 419         }
 420 cleanup:
 421         posix_acl_release(acl);
 422         return ret;
 423 }
 424
 425 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 426                                           char *list,
 427                                           size_t list_len,
 428                                           const char *name,
 429                                           size_t name_len,
 430                                           int type)
 431 {
 432         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 433         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 434
 435         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 436                 return 0;
 437
 438         if (list && size <= list_len)
 439                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 440         return size;
 441 }
 442
 443 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 444                                            char *list,
 445                                            size_t list_len,
 446                                            const char *name,
 447                                            size_t name_len,
 448                                            int type)
 449 {
 450         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 451         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 452
 453         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 454                 return 0;
 455
 456         if (list && size <= list_len)
 457                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 458         return size;
 459 }
 460
 461 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 462                 void *buffer, size_t size, int type)
 463 {
 464         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 465         struct posix_acl *acl;
 466         int ret;
 467
 468         if (strcmp(name, "") != 0)
 469                 return -EINVAL;
 470         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 471                 return -EOPNOTSUPP;
 472
 473         acl = ocfs2_get_acl(dentry->d_inode, type);
 474         if (IS_ERR(acl))
 475                 return PTR_ERR(acl);
 476         if (acl == NULL)
 477                 return -ENODATA;
 478         ret = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
 479         posix_acl_release(acl);
 480
 481         return ret;
 482 }
 483
 484 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 485                 const void *value, size_t size, int flags, int type)
 486 {
 487         struct inode *inode = dentry->d_inode;
 488         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 489         struct posix_acl *acl;
 490         int ret = 0;
 491
 492         if (strcmp(name, "") != 0)
 493                 return -EINVAL;
 494         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 495                 return -EOPNOTSUPP;
 496
 497         if (!inode_owner_or_capable(inode))
 498                 return -EPERM;
 499
 500         if (value) {
 501                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
 502                 if (IS_ERR(acl))
 503                         return PTR_ERR(acl);
 504                 else if (acl) {
 505                         ret = posix_acl_valid(acl);
 506                         if (ret)
 507                                 goto cleanup;
 508                 }
 509         } else
 510                 acl = NULL;
 511
 512         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 513
 514 cleanup:
 515         posix_acl_release(acl);
 516         return ret;
 517 }
 518
 519 const struct xattr_handler ocfs2_xattr_acl_access_handler = {
 520         .prefix = POSIX_ACL_XATTR_ACCESS,
 521         .flags  = ACL_TYPE_ACCESS,
 522         .list   = ocfs2_xattr_list_acl_access,
 523         .get    = ocfs2_xattr_get_acl,
 524         .set    = ocfs2_xattr_set_acl,
 525 };
 526
 527 const struct xattr_handler ocfs2_xattr_acl_default_handler = {
 528         .prefix = POSIX_ACL_XATTR_DEFAULT,
 529         .flags  = ACL_TYPE_DEFAULT,
 530         .list   = ocfs2_xattr_list_acl_default,
 531         .get    = ocfs2_xattr_get_acl,
 532         .set    = ocfs2_xattr_set_acl,
 533 };