fs/f2fs/xattr.c

   1 /*
   2  * fs/f2fs/xattr.c
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *             http://www.samsung.com/
   6  *
   7  * Portions of this code from linux/fs/ext2/xattr.c
   8  *
   9  * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
  10  *
  11  * Fix by Harrison Xing <harrison@mountainviewdata.com>.
  12  * Extended attributes for symlinks and special files added per
  13  *  suggestion of Luka Renko <luka.renko@hermes.si>.
  14  * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
  15  *  Red Hat Inc.
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License version 2 as
  19  * published by the Free Software Foundation.
  20  */
  21 #include <linux/rwsem.h>
  22 #include <linux/f2fs_fs.h>
  23 #include <linux/security.h>
  24 #include <linux/posix_acl_xattr.h>
  25 #include "f2fs.h"
  26 #include "xattr.h"
  27
  28 static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
  29                 struct dentry *unused, struct inode *inode,
  30                 const char *name, void *buffer, size_t size)
  31 {
  32         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
  33
  34         switch (handler->flags) {
  35         case F2FS_XATTR_INDEX_USER:
  36                 if (!test_opt(sbi, XATTR_USER))
  37                         return -EOPNOTSUPP;
  38                 break;
  39         case F2FS_XATTR_INDEX_TRUSTED:
  40                 if (!capable(CAP_SYS_ADMIN))
  41                         return -EPERM;
  42                 break;
  43         case F2FS_XATTR_INDEX_SECURITY:
  44                 break;
  45         default:
  46                 return -EINVAL;
  47         }
  48         return f2fs_getxattr(inode, handler->flags, name,
  49                              buffer, size, NULL);
  50 }
  51
  52 static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
  53                 struct dentry *unused, struct inode *inode,
  54                 const char *name, const void *value,
  55                 size_t size, int flags)
  56 {
  57         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
  58
  59         switch (handler->flags) {
  60         case F2FS_XATTR_INDEX_USER:
  61                 if (!test_opt(sbi, XATTR_USER))
  62                         return -EOPNOTSUPP;
  63                 break;
  64         case F2FS_XATTR_INDEX_TRUSTED:
  65                 if (!capable(CAP_SYS_ADMIN))
  66                         return -EPERM;
  67                 break;
  68         case F2FS_XATTR_INDEX_SECURITY:
  69                 break;
  70         default:
  71                 return -EINVAL;
  72         }
  73         return f2fs_setxattr(inode, handler->flags, name,
  74                                         value, size, NULL, flags);
  75 }
  76
  77 static bool f2fs_xattr_user_list(struct dentry *dentry)
  78 {
  79         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  80
  81         return test_opt(sbi, XATTR_USER);
  82 }
  83
  84 static bool f2fs_xattr_trusted_list(struct dentry *dentry)
  85 {
  86         return capable(CAP_SYS_ADMIN);
  87 }
  88
  89 static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
  90                 struct dentry *unused, struct inode *inode,
  91                 const char *name, void *buffer, size_t size)
  92 {
  93         if (buffer)
  94                 *((char *)buffer) = F2FS_I(inode)->i_advise;
  95         return sizeof(char);
  96 }
  97
  98 static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
  99                 struct dentry *unused, struct inode *inode,
 100                 const char *name, const void *value,
 101                 size_t size, int flags)
 102 {
 103         if (!inode_owner_or_capable(inode))
 104                 return -EPERM;
 105         if (value == NULL)
 106                 return -EINVAL;
 107
 108         F2FS_I(inode)->i_advise |= *(char *)value;
 109         f2fs_mark_inode_dirty_sync(inode);
 110         return 0;
 111 }
 112
 113 #ifdef CONFIG_F2FS_FS_SECURITY
 114 static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 115                 void *page)
 116 {
 117         const struct xattr *xattr;
 118         int err = 0;
 119
 120         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
 121                 err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
 122                                 xattr->name, xattr->value,
 123                                 xattr->value_len, (struct page *)page, 0);
 124                 if (err < 0)
 125                         break;
 126         }
 127         return err;
 128 }
 129
 130 int f2fs_init_security(struct inode *inode, struct inode *dir,
 131                                 const struct qstr *qstr, struct page *ipage)
 132 {
 133         return security_inode_init_security(inode, dir, qstr,
 134                                 &f2fs_initxattrs, ipage);
 135 }
 136 #endif
 137
 138 const struct xattr_handler f2fs_xattr_user_handler = {
 139         .prefix = XATTR_USER_PREFIX,
 140         .flags  = F2FS_XATTR_INDEX_USER,
 141         .list   = f2fs_xattr_user_list,
 142         .get    = f2fs_xattr_generic_get,
 143         .set    = f2fs_xattr_generic_set,
 144 };
 145
 146 const struct xattr_handler f2fs_xattr_trusted_handler = {
 147         .prefix = XATTR_TRUSTED_PREFIX,
 148         .flags  = F2FS_XATTR_INDEX_TRUSTED,
 149         .list   = f2fs_xattr_trusted_list,
 150         .get    = f2fs_xattr_generic_get,
 151         .set    = f2fs_xattr_generic_set,
 152 };
 153
 154 const struct xattr_handler f2fs_xattr_advise_handler = {
 155         .name   = F2FS_SYSTEM_ADVISE_NAME,
 156         .flags  = F2FS_XATTR_INDEX_ADVISE,
 157         .get    = f2fs_xattr_advise_get,
 158         .set    = f2fs_xattr_advise_set,
 159 };
 160
 161 const struct xattr_handler f2fs_xattr_security_handler = {
 162         .prefix = XATTR_SECURITY_PREFIX,
 163         .flags  = F2FS_XATTR_INDEX_SECURITY,
 164         .get    = f2fs_xattr_generic_get,
 165         .set    = f2fs_xattr_generic_set,
 166 };
 167
 168 static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 169         [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
 170 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 171         [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
 172         [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
 173 #endif
 174         [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
 175 #ifdef CONFIG_F2FS_FS_SECURITY
 176         [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
 177 #endif
 178         [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
 179 };
 180
 181 const struct xattr_handler *f2fs_xattr_handlers[] = {
 182         &f2fs_xattr_user_handler,
 183 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 184         &posix_acl_access_xattr_handler,
 185         &posix_acl_default_xattr_handler,
 186 #endif
 187         &f2fs_xattr_trusted_handler,
 188 #ifdef CONFIG_F2FS_FS_SECURITY
 189         &f2fs_xattr_security_handler,
 190 #endif
 191         &f2fs_xattr_advise_handler,
 192         NULL,
 193 };
 194
 195 static inline const struct xattr_handler *f2fs_xattr_handler(int index)
 196 {
 197         const struct xattr_handler *handler = NULL;
 198
 199         if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
 200                 handler = f2fs_xattr_handler_map[index];
 201         return handler;
 202 }
 203
 204 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index,
 205                                         size_t len, const char *name)
 206 {
 207         struct f2fs_xattr_entry *entry;
 208
 209         list_for_each_xattr(entry, base_addr) {
 210                 if (entry->e_name_index != index)
 211                         continue;
 212                 if (entry->e_name_len != len)
 213                         continue;
 214                 if (!memcmp(entry->e_name, name, len))
 215                         break;
 216         }
 217         return entry;
 218 }
 219
 220 static int read_all_xattrs(struct inode *inode, struct page *ipage,
 221                                                         void **base_addr)
 222 {
 223         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 224         struct f2fs_xattr_header *header;
 225         size_t size = PAGE_SIZE, inline_size = 0;
 226         void *txattr_addr;
 227         int err;
 228
 229         inline_size = inline_xattr_size(inode);
 230
 231         txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
 232         if (!txattr_addr)
 233                 return -ENOMEM;
 234
 235         /* read from inline xattr */
 236         if (inline_size) {
 237                 struct page *page = NULL;
 238                 void *inline_addr;
 239
 240                 if (ipage) {
 241                         inline_addr = inline_xattr_addr(ipage);
 242                 } else {
 243                         page = get_node_page(sbi, inode->i_ino);
 244                         if (IS_ERR(page)) {
 245                                 err = PTR_ERR(page);
 246                                 goto fail;
 247                         }
 248                         inline_addr = inline_xattr_addr(page);
 249                 }
 250                 memcpy(txattr_addr, inline_addr, inline_size);
 251                 f2fs_put_page(page, 1);
 252         }
 253
 254         /* read from xattr node block */
 255         if (F2FS_I(inode)->i_xattr_nid) {
 256                 struct page *xpage;
 257                 void *xattr_addr;
 258
 259                 /* The inode already has an extended attribute block. */
 260                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 261                 if (IS_ERR(xpage)) {
 262                         err = PTR_ERR(xpage);
 263                         goto fail;
 264                 }
 265
 266                 xattr_addr = page_address(xpage);
 267                 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
 268                 f2fs_put_page(xpage, 1);
 269         }
 270
 271         header = XATTR_HDR(txattr_addr);
 272
 273         /* never been allocated xattrs */
 274         if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
 275                 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
 276                 header->h_refcount = cpu_to_le32(1);
 277         }
 278         *base_addr = txattr_addr;
 279         return 0;
 280 fail:
 281         kzfree(txattr_addr);
 282         return err;
 283 }
 284
 285 static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
 286                                 void *txattr_addr, struct page *ipage)
 287 {
 288         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 289         size_t inline_size = 0;
 290         void *xattr_addr;
 291         struct page *xpage;
 292         nid_t new_nid = 0;
 293         int err;
 294
 295         inline_size = inline_xattr_size(inode);
 296
 297         if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
 298                 if (!alloc_nid(sbi, &new_nid))
 299                         return -ENOSPC;
 300
 301         /* write to inline xattr */
 302         if (inline_size) {
 303                 struct page *page = NULL;
 304                 void *inline_addr;
 305
 306                 if (ipage) {
 307                         inline_addr = inline_xattr_addr(ipage);
 308                         f2fs_wait_on_page_writeback(ipage, NODE, true);
 309                         set_page_dirty(ipage);
 310                 } else {
 311                         page = get_node_page(sbi, inode->i_ino);
 312                         if (IS_ERR(page)) {
 313                                 alloc_nid_failed(sbi, new_nid);
 314                                 return PTR_ERR(page);
 315                         }
 316                         inline_addr = inline_xattr_addr(page);
 317                         f2fs_wait_on_page_writeback(page, NODE, true);
 318                 }
 319                 memcpy(inline_addr, txattr_addr, inline_size);
 320                 f2fs_put_page(page, 1);
 321
 322                 /* no need to use xattr node block */
 323                 if (hsize <= inline_size) {
 324                         err = truncate_xattr_node(inode, ipage);
 325                         alloc_nid_failed(sbi, new_nid);
 326                         return err;
 327                 }
 328         }
 329
 330         /* write to xattr node block */
 331         if (F2FS_I(inode)->i_xattr_nid) {
 332                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 333                 if (IS_ERR(xpage)) {
 334                         alloc_nid_failed(sbi, new_nid);
 335                         return PTR_ERR(xpage);
 336                 }
 337                 f2fs_bug_on(sbi, new_nid);
 338                 f2fs_wait_on_page_writeback(xpage, NODE, true);
 339         } else {
 340                 struct dnode_of_data dn;
 341                 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
 342                 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
 343                 if (IS_ERR(xpage)) {
 344                         alloc_nid_failed(sbi, new_nid);
 345                         return PTR_ERR(xpage);
 346                 }
 347                 alloc_nid_done(sbi, new_nid);
 348         }
 349
 350         xattr_addr = page_address(xpage);
 351         memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
 352                                                 sizeof(struct node_footer));
 353         set_page_dirty(xpage);
 354         f2fs_put_page(xpage, 1);
 355
 356         /* need to checkpoint during fsync */
 357         F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
 358         return 0;
 359 }
 360
 361 int f2fs_getxattr(struct inode *inode, int index, const char *name,
 362                 void *buffer, size_t buffer_size, struct page *ipage)
 363 {
 364         struct f2fs_xattr_entry *entry;
 365         void *base_addr;
 366         int error = 0;
 367         size_t size, len;
 368
 369         if (name == NULL)
 370                 return -EINVAL;
 371
 372         len = strlen(name);
 373         if (len > F2FS_NAME_LEN)
 374                 return -ERANGE;
 375
 376         error = read_all_xattrs(inode, ipage, &base_addr);
 377         if (error)
 378                 return error;
 379
 380         entry = __find_xattr(base_addr, index, len, name);
 381         if (IS_XATTR_LAST_ENTRY(entry)) {
 382                 error = -ENODATA;
 383                 goto cleanup;
 384         }
 385
 386         size = le16_to_cpu(entry->e_value_size);
 387
 388         if (buffer && size > buffer_size) {
 389                 error = -ERANGE;
 390                 goto cleanup;
 391         }
 392
 393         if (buffer) {
 394                 char *pval = entry->e_name + entry->e_name_len;
 395                 memcpy(buffer, pval, size);
 396         }
 397         error = size;
 398
 399 cleanup:
 400         kzfree(base_addr);
 401         return error;
 402 }
 403
 404 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 405 {
 406         struct inode *inode = d_inode(dentry);
 407         struct f2fs_xattr_entry *entry;
 408         void *base_addr;
 409         int error = 0;
 410         size_t rest = buffer_size;
 411
 412         error = read_all_xattrs(inode, NULL, &base_addr);
 413         if (error)
 414                 return error;
 415
 416         list_for_each_xattr(entry, base_addr) {
 417                 const struct xattr_handler *handler =
 418                         f2fs_xattr_handler(entry->e_name_index);
 419                 const char *prefix;
 420                 size_t prefix_len;
 421                 size_t size;
 422
 423                 if (!handler || (handler->list && !handler->list(dentry)))
 424                         continue;
 425
 426                 prefix = handler->prefix ?: handler->name;
 427                 prefix_len = strlen(prefix);
 428                 size = prefix_len + entry->e_name_len + 1;
 429                 if (buffer) {
 430                         if (size > rest) {
 431                                 error = -ERANGE;
 432                                 goto cleanup;
 433                         }
 434                         memcpy(buffer, prefix, prefix_len);
 435                         buffer += prefix_len;
 436                         memcpy(buffer, entry->e_name, entry->e_name_len);
 437                         buffer += entry->e_name_len;
 438                         *buffer++ = 0;
 439                 }
 440                 rest -= size;
 441         }
 442         error = buffer_size - rest;
 443 cleanup:
 444         kzfree(base_addr);
 445         return error;
 446 }
 447
 448 static int __f2fs_setxattr(struct inode *inode, int index,
 449                         const char *name, const void *value, size_t size,
 450                         struct page *ipage, int flags)
 451 {
 452         struct f2fs_xattr_entry *here, *last;
 453         void *base_addr;
 454         int found, newsize;
 455         size_t len;
 456         __u32 new_hsize;
 457         int error = 0;
 458
 459         if (name == NULL)
 460                 return -EINVAL;
 461
 462         if (value == NULL)
 463                 size = 0;
 464
 465         len = strlen(name);
 466
 467         if (len > F2FS_NAME_LEN)
 468                 return -ERANGE;
 469
 470         if (size > MAX_VALUE_LEN(inode))
 471                 return -E2BIG;
 472
 473         error = read_all_xattrs(inode, ipage, &base_addr);
 474         if (error)
 475                 return error;
 476
 477         /* find entry with wanted name. */
 478         here = __find_xattr(base_addr, index, len, name);
 479
 480         found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
 481
 482         if ((flags & XATTR_REPLACE) && !found) {
 483                 error = -ENODATA;
 484                 goto exit;
 485         } else if ((flags & XATTR_CREATE) && found) {
 486                 error = -EEXIST;
 487                 goto exit;
 488         }
 489
 490         last = here;
 491         while (!IS_XATTR_LAST_ENTRY(last))
 492                 last = XATTR_NEXT_ENTRY(last);
 493
 494         newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
 495
 496         /* 1. Check space */
 497         if (value) {
 498                 int free;
 499                 /*
 500                  * If value is NULL, it is remove operation.
 501                  * In case of update operation, we calculate free.
 502                  */
 503                 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
 504                 if (found)
 505                         free = free + ENTRY_SIZE(here);
 506
 507                 if (unlikely(free < newsize)) {
 508                         error = -E2BIG;
 509                         goto exit;
 510                 }
 511         }
 512
 513         /* 2. Remove old entry */
 514         if (found) {
 515                 /*
 516                  * If entry is found, remove old entry.
 517                  * If not found, remove operation is not needed.
 518                  */
 519                 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
 520                 int oldsize = ENTRY_SIZE(here);
 521
 522                 memmove(here, next, (char *)last - (char *)next);
 523                 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
 524                 memset(last, 0, oldsize);
 525         }
 526
 527         new_hsize = (char *)last - (char *)base_addr;
 528
 529         /* 3. Write new entry */
 530         if (value) {
 531                 char *pval;
 532                 /*
 533                  * Before we come here, old entry is removed.
 534                  * We just write new entry.
 535                  */
 536                 last->e_name_index = index;
 537                 last->e_name_len = len;
 538                 memcpy(last->e_name, name, len);
 539                 pval = last->e_name + len;
 540                 memcpy(pval, value, size);
 541                 last->e_value_size = cpu_to_le16(size);
 542                 new_hsize += newsize;
 543         }
 544
 545         error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
 546         if (error)
 547                 goto exit;
 548
 549         if (is_inode_flag_set(inode, FI_ACL_MODE)) {
 550                 inode->i_mode = F2FS_I(inode)->i_acl_mode;
 551                 inode->i_ctime = current_time(inode);
 552                 clear_inode_flag(inode, FI_ACL_MODE);
 553         }
 554         if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
 555                         !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
 556                 f2fs_set_encrypted_inode(inode);
 557         f2fs_mark_inode_dirty_sync(inode);
 558         if (!error && S_ISDIR(inode->i_mode))
 559                 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
 560 exit:
 561         kzfree(base_addr);
 562         return error;
 563 }
 564
 565 int f2fs_setxattr(struct inode *inode, int index, const char *name,
 566                                 const void *value, size_t size,
 567                                 struct page *ipage, int flags)
 568 {
 569         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 570         int err;
 571
 572         /* this case is only from init_inode_metadata */
 573         if (ipage)
 574                 return __f2fs_setxattr(inode, index, name, value,
 575                                                 size, ipage, flags);
 576         f2fs_balance_fs(sbi, true);
 577
 578         f2fs_lock_op(sbi);
 579         /* protect xattr_ver */
 580         down_write(&F2FS_I(inode)->i_sem);
 581         err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
 582         up_write(&F2FS_I(inode)->i_sem);
 583         f2fs_unlock_op(sbi);
 584
 585         f2fs_update_time(sbi, REQ_TIME);
 586         return err;
 587 }