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, <[email protected]>
  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         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  */
  91 static 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
 126 static 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  */
 171 static 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  */
 202 static 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
 245 out_commit:
 246         if (commit_handle)
 247                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 248 out_brelse:
 249         brelse(di_bh);
 250 out:
 251         return ret;
 252 }
 253
 254 /*
 255  * Set the access or default ACL of an inode.
 256  */
 257 static 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
 320 struct 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
 342 int 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  */
 370 int 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         }
 424 cleanup:
 425         posix_acl_release(acl);
 426         return ret;
 427 }
 428
 429 static 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
 447 static 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
 465 static 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
 488 static 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
 518 cleanup:
 519         posix_acl_release(acl);
 520         return ret;
 521 }
 522
 523 const 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
 531 const 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 };