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 size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
  29                 size_t list_size, const char *name, size_t name_len, int type)
  30 {
  31         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  32         int total_len, prefix_len = 0;
  33         const char *prefix = NULL;
  34
  35         switch (type) {
  36         case F2FS_XATTR_INDEX_USER:
  37                 if (!test_opt(sbi, XATTR_USER))
  38                         return -EOPNOTSUPP;
  39                 prefix = XATTR_USER_PREFIX;
  40                 prefix_len = XATTR_USER_PREFIX_LEN;
  41                 break;
  42         case F2FS_XATTR_INDEX_TRUSTED:
  43                 if (!capable(CAP_SYS_ADMIN))
  44                         return -EPERM;
  45                 prefix = XATTR_TRUSTED_PREFIX;
  46                 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  47                 break;
  48         case F2FS_XATTR_INDEX_SECURITY:
  49                 prefix = XATTR_SECURITY_PREFIX;
  50                 prefix_len = XATTR_SECURITY_PREFIX_LEN;
  51                 break;
  52         default:
  53                 return -EINVAL;
  54         }
  55
  56         total_len = prefix_len + name_len + 1;
  57         if (list && total_len <= list_size) {
  58                 memcpy(list, prefix, prefix_len);
  59                 memcpy(list + prefix_len, name, name_len);
  60                 list[prefix_len + name_len] = '\0';
  61         }
  62         return total_len;
  63 }
  64
  65 static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
  66                 void *buffer, size_t size, int type)
  67 {
  68         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  69
  70         switch (type) {
  71         case F2FS_XATTR_INDEX_USER:
  72                 if (!test_opt(sbi, XATTR_USER))
  73                         return -EOPNOTSUPP;
  74                 break;
  75         case F2FS_XATTR_INDEX_TRUSTED:
  76                 if (!capable(CAP_SYS_ADMIN))
  77                         return -EPERM;
  78                 break;
  79         case F2FS_XATTR_INDEX_SECURITY:
  80                 break;
  81         default:
  82                 return -EINVAL;
  83         }
  84         if (strcmp(name, "") == 0)
  85                 return -EINVAL;
  86         return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
  87 }
  88
  89 static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
  90                 const void *value, size_t size, int flags, int type)
  91 {
  92         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  93
  94         switch (type) {
  95         case F2FS_XATTR_INDEX_USER:
  96                 if (!test_opt(sbi, XATTR_USER))
  97                         return -EOPNOTSUPP;
  98                 break;
  99         case F2FS_XATTR_INDEX_TRUSTED:
 100                 if (!capable(CAP_SYS_ADMIN))
 101                         return -EPERM;
 102                 break;
 103         case F2FS_XATTR_INDEX_SECURITY:
 104                 break;
 105         default:
 106                 return -EINVAL;
 107         }
 108         if (strcmp(name, "") == 0)
 109                 return -EINVAL;
 110
 111         return f2fs_setxattr(dentry->d_inode, type, name, value, size, NULL);
 112 }
 113
 114 static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
 115                 size_t list_size, const char *name, size_t name_len, int type)
 116 {
 117         const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
 118         size_t size;
 119
 120         if (type != F2FS_XATTR_INDEX_ADVISE)
 121                 return 0;
 122
 123         size = strlen(xname) + 1;
 124         if (list && size <= list_size)
 125                 memcpy(list, xname, size);
 126         return size;
 127 }
 128
 129 static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
 130                 void *buffer, size_t size, int type)
 131 {
 132         struct inode *inode = dentry->d_inode;
 133
 134         if (strcmp(name, "") != 0)
 135                 return -EINVAL;
 136
 137         *((char *)buffer) = F2FS_I(inode)->i_advise;
 138         return sizeof(char);
 139 }
 140
 141 static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
 142                 const void *value, size_t size, int flags, int type)
 143 {
 144         struct inode *inode = dentry->d_inode;
 145
 146         if (strcmp(name, "") != 0)
 147                 return -EINVAL;
 148         if (!inode_owner_or_capable(inode))
 149                 return -EPERM;
 150         if (value == NULL)
 151                 return -EINVAL;
 152
 153         F2FS_I(inode)->i_advise |= *(char *)value;
 154         return 0;
 155 }
 156
 157 #ifdef CONFIG_F2FS_FS_SECURITY
 158 static int __f2fs_setxattr(struct inode *inode, int name_index,
 159                         const char *name, const void *value, size_t value_len,
 160                         struct page *ipage);
 161 static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 162                 void *page)
 163 {
 164         const struct xattr *xattr;
 165         int err = 0;
 166
 167         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
 168                 err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
 169                                 xattr->name, xattr->value,
 170                                 xattr->value_len, (struct page *)page);
 171                 if (err < 0)
 172                         break;
 173         }
 174         return err;
 175 }
 176
 177 int f2fs_init_security(struct inode *inode, struct inode *dir,
 178                                 const struct qstr *qstr, struct page *ipage)
 179 {
 180         return security_inode_init_security(inode, dir, qstr,
 181                                 &f2fs_initxattrs, ipage);
 182 }
 183 #endif
 184
 185 const struct xattr_handler f2fs_xattr_user_handler = {
 186         .prefix = XATTR_USER_PREFIX,
 187         .flags  = F2FS_XATTR_INDEX_USER,
 188         .list   = f2fs_xattr_generic_list,
 189         .get    = f2fs_xattr_generic_get,
 190         .set    = f2fs_xattr_generic_set,
 191 };
 192
 193 const struct xattr_handler f2fs_xattr_trusted_handler = {
 194         .prefix = XATTR_TRUSTED_PREFIX,
 195         .flags  = F2FS_XATTR_INDEX_TRUSTED,
 196         .list   = f2fs_xattr_generic_list,
 197         .get    = f2fs_xattr_generic_get,
 198         .set    = f2fs_xattr_generic_set,
 199 };
 200
 201 const struct xattr_handler f2fs_xattr_advise_handler = {
 202         .prefix = F2FS_SYSTEM_ADVISE_PREFIX,
 203         .flags  = F2FS_XATTR_INDEX_ADVISE,
 204         .list   = f2fs_xattr_advise_list,
 205         .get    = f2fs_xattr_advise_get,
 206         .set    = f2fs_xattr_advise_set,
 207 };
 208
 209 const struct xattr_handler f2fs_xattr_security_handler = {
 210         .prefix = XATTR_SECURITY_PREFIX,
 211         .flags  = F2FS_XATTR_INDEX_SECURITY,
 212         .list   = f2fs_xattr_generic_list,
 213         .get    = f2fs_xattr_generic_get,
 214         .set    = f2fs_xattr_generic_set,
 215 };
 216
 217 static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 218         [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
 219 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 220         [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
 221         [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
 222 #endif
 223         [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
 224 #ifdef CONFIG_F2FS_FS_SECURITY
 225         [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
 226 #endif
 227         [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
 228 };
 229
 230 const struct xattr_handler *f2fs_xattr_handlers[] = {
 231         &f2fs_xattr_user_handler,
 232 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 233         &posix_acl_access_xattr_handler,
 234         &posix_acl_default_xattr_handler,
 235 #endif
 236         &f2fs_xattr_trusted_handler,
 237 #ifdef CONFIG_F2FS_FS_SECURITY
 238         &f2fs_xattr_security_handler,
 239 #endif
 240         &f2fs_xattr_advise_handler,
 241         NULL,
 242 };
 243
 244 static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
 245 {
 246         const struct xattr_handler *handler = NULL;
 247
 248         if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
 249                 handler = f2fs_xattr_handler_map[name_index];
 250         return handler;
 251 }
 252
 253 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int name_index,
 254                                         size_t name_len, const char *name)
 255 {
 256         struct f2fs_xattr_entry *entry;
 257
 258         list_for_each_xattr(entry, base_addr) {
 259                 if (entry->e_name_index != name_index)
 260                         continue;
 261                 if (entry->e_name_len != name_len)
 262                         continue;
 263                 if (!memcmp(entry->e_name, name, name_len))
 264                         break;
 265         }
 266         return entry;
 267 }
 268
 269 static void *read_all_xattrs(struct inode *inode, struct page *ipage)
 270 {
 271         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 272         struct f2fs_xattr_header *header;
 273         size_t size = PAGE_SIZE, inline_size = 0;
 274         void *txattr_addr;
 275
 276         inline_size = inline_xattr_size(inode);
 277
 278         txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
 279         if (!txattr_addr)
 280                 return NULL;
 281
 282         /* read from inline xattr */
 283         if (inline_size) {
 284                 struct page *page = NULL;
 285                 void *inline_addr;
 286
 287                 if (ipage) {
 288                         inline_addr = inline_xattr_addr(ipage);
 289                 } else {
 290                         page = get_node_page(sbi, inode->i_ino);
 291                         if (IS_ERR(page))
 292                                 goto fail;
 293                         inline_addr = inline_xattr_addr(page);
 294                 }
 295                 memcpy(txattr_addr, inline_addr, inline_size);
 296                 f2fs_put_page(page, 1);
 297         }
 298
 299         /* read from xattr node block */
 300         if (F2FS_I(inode)->i_xattr_nid) {
 301                 struct page *xpage;
 302                 void *xattr_addr;
 303
 304                 /* The inode already has an extended attribute block. */
 305                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 306                 if (IS_ERR(xpage))
 307                         goto fail;
 308
 309                 xattr_addr = page_address(xpage);
 310                 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
 311                 f2fs_put_page(xpage, 1);
 312         }
 313
 314         header = XATTR_HDR(txattr_addr);
 315
 316         /* never been allocated xattrs */
 317         if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
 318                 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
 319                 header->h_refcount = cpu_to_le32(1);
 320         }
 321         return txattr_addr;
 322 fail:
 323         kzfree(txattr_addr);
 324         return NULL;
 325 }
 326
 327 static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
 328                                 void *txattr_addr, struct page *ipage)
 329 {
 330         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 331         size_t inline_size = 0;
 332         void *xattr_addr;
 333         struct page *xpage;
 334         nid_t new_nid = 0;
 335         int err;
 336
 337         inline_size = inline_xattr_size(inode);
 338
 339         if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
 340                 if (!alloc_nid(sbi, &new_nid))
 341                         return -ENOSPC;
 342
 343         /* write to inline xattr */
 344         if (inline_size) {
 345                 struct page *page = NULL;
 346                 void *inline_addr;
 347
 348                 if (ipage) {
 349                         inline_addr = inline_xattr_addr(ipage);
 350                 } else {
 351                         page = get_node_page(sbi, inode->i_ino);
 352                         if (IS_ERR(page)) {
 353                                 alloc_nid_failed(sbi, new_nid);
 354                                 return PTR_ERR(page);
 355                         }
 356                         inline_addr = inline_xattr_addr(page);
 357                 }
 358                 memcpy(inline_addr, txattr_addr, inline_size);
 359                 f2fs_put_page(page, 1);
 360
 361                 /* no need to use xattr node block */
 362                 if (hsize <= inline_size) {
 363                         err = truncate_xattr_node(inode, ipage);
 364                         alloc_nid_failed(sbi, new_nid);
 365                         return err;
 366                 }
 367         }
 368
 369         /* write to xattr node block */
 370         if (F2FS_I(inode)->i_xattr_nid) {
 371                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 372                 if (IS_ERR(xpage)) {
 373                         alloc_nid_failed(sbi, new_nid);
 374                         return PTR_ERR(xpage);
 375                 }
 376                 f2fs_bug_on(new_nid);
 377         } else {
 378                 struct dnode_of_data dn;
 379                 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
 380                 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
 381                 if (IS_ERR(xpage)) {
 382                         alloc_nid_failed(sbi, new_nid);
 383                         return PTR_ERR(xpage);
 384                 }
 385                 alloc_nid_done(sbi, new_nid);
 386         }
 387
 388         xattr_addr = page_address(xpage);
 389         memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
 390                                                 sizeof(struct node_footer));
 391         set_page_dirty(xpage);
 392         f2fs_put_page(xpage, 1);
 393
 394         /* need to checkpoint during fsync */
 395         F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
 396         return 0;
 397 }
 398
 399 int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
 400                 void *buffer, size_t buffer_size)
 401 {
 402         struct f2fs_xattr_entry *entry;
 403         void *base_addr;
 404         int error = 0;
 405         size_t value_len, name_len;
 406
 407         if (name == NULL)
 408                 return -EINVAL;
 409         name_len = strlen(name);
 410         if (name_len > F2FS_NAME_LEN)
 411                 return -ERANGE;
 412
 413         base_addr = read_all_xattrs(inode, NULL);
 414         if (!base_addr)
 415                 return -ENOMEM;
 416
 417         entry = __find_xattr(base_addr, name_index, name_len, name);
 418         if (IS_XATTR_LAST_ENTRY(entry)) {
 419                 error = -ENODATA;
 420                 goto cleanup;
 421         }
 422
 423         value_len = le16_to_cpu(entry->e_value_size);
 424
 425         if (buffer && value_len > buffer_size) {
 426                 error = -ERANGE;
 427                 goto cleanup;
 428         }
 429
 430         if (buffer) {
 431                 char *pval = entry->e_name + entry->e_name_len;
 432                 memcpy(buffer, pval, value_len);
 433         }
 434         error = value_len;
 435
 436 cleanup:
 437         kzfree(base_addr);
 438         return error;
 439 }
 440
 441 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 442 {
 443         struct inode *inode = dentry->d_inode;
 444         struct f2fs_xattr_entry *entry;
 445         void *base_addr;
 446         int error = 0;
 447         size_t rest = buffer_size;
 448
 449         base_addr = read_all_xattrs(inode, NULL);
 450         if (!base_addr)
 451                 return -ENOMEM;
 452
 453         list_for_each_xattr(entry, base_addr) {
 454                 const struct xattr_handler *handler =
 455                         f2fs_xattr_handler(entry->e_name_index);
 456                 size_t size;
 457
 458                 if (!handler)
 459                         continue;
 460
 461                 size = handler->list(dentry, buffer, rest, entry->e_name,
 462                                 entry->e_name_len, handler->flags);
 463                 if (buffer && size > rest) {
 464                         error = -ERANGE;
 465                         goto cleanup;
 466                 }
 467
 468                 if (buffer)
 469                         buffer += size;
 470                 rest -= size;
 471         }
 472         error = buffer_size - rest;
 473 cleanup:
 474         kzfree(base_addr);
 475         return error;
 476 }
 477
 478 static int __f2fs_setxattr(struct inode *inode, int name_index,
 479                         const char *name, const void *value, size_t value_len,
 480                         struct page *ipage)
 481 {
 482         struct f2fs_inode_info *fi = F2FS_I(inode);
 483         struct f2fs_xattr_entry *here, *last;
 484         void *base_addr;
 485         int found, newsize;
 486         size_t name_len;
 487         __u32 new_hsize;
 488         int error = -ENOMEM;
 489
 490         if (name == NULL)
 491                 return -EINVAL;
 492
 493         if (value == NULL)
 494                 value_len = 0;
 495
 496         name_len = strlen(name);
 497
 498         if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode))
 499                 return -ERANGE;
 500
 501         base_addr = read_all_xattrs(inode, ipage);
 502         if (!base_addr)
 503                 goto exit;
 504
 505         /* find entry with wanted name. */
 506         here = __find_xattr(base_addr, name_index, name_len, name);
 507
 508         found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
 509         last = here;
 510
 511         while (!IS_XATTR_LAST_ENTRY(last))
 512                 last = XATTR_NEXT_ENTRY(last);
 513
 514         newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
 515                         name_len + value_len);
 516
 517         /* 1. Check space */
 518         if (value) {
 519                 int free;
 520                 /*
 521                  * If value is NULL, it is remove operation.
 522                  * In case of update operation, we caculate free.
 523                  */
 524                 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
 525                 if (found)
 526                         free = free + ENTRY_SIZE(here);
 527
 528                 if (unlikely(free < newsize)) {
 529                         error = -ENOSPC;
 530                         goto exit;
 531                 }
 532         }
 533
 534         /* 2. Remove old entry */
 535         if (found) {
 536                 /*
 537                  * If entry is found, remove old entry.
 538                  * If not found, remove operation is not needed.
 539                  */
 540                 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
 541                 int oldsize = ENTRY_SIZE(here);
 542
 543                 memmove(here, next, (char *)last - (char *)next);
 544                 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
 545                 memset(last, 0, oldsize);
 546         }
 547
 548         new_hsize = (char *)last - (char *)base_addr;
 549
 550         /* 3. Write new entry */
 551         if (value) {
 552                 char *pval;
 553                 /*
 554                  * Before we come here, old entry is removed.
 555                  * We just write new entry.
 556                  */
 557                 memset(last, 0, newsize);
 558                 last->e_name_index = name_index;
 559                 last->e_name_len = name_len;
 560                 memcpy(last->e_name, name, name_len);
 561                 pval = last->e_name + name_len;
 562                 memcpy(pval, value, value_len);
 563                 last->e_value_size = cpu_to_le16(value_len);
 564                 new_hsize += newsize;
 565         }
 566
 567         error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
 568         if (error)
 569                 goto exit;
 570
 571         if (is_inode_flag_set(fi, FI_ACL_MODE)) {
 572                 inode->i_mode = fi->i_acl_mode;
 573                 inode->i_ctime = CURRENT_TIME;
 574                 clear_inode_flag(fi, FI_ACL_MODE);
 575         }
 576
 577         if (ipage)
 578                 update_inode(inode, ipage);
 579         else
 580                 update_inode_page(inode);
 581 exit:
 582         kzfree(base_addr);
 583         return error;
 584 }
 585
 586 int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
 587                         const void *value, size_t value_len, struct page *ipage)
 588 {
 589         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 590         int err;
 591
 592         f2fs_balance_fs(sbi);
 593
 594         f2fs_lock_op(sbi);
 595         /* protect xattr_ver */
 596         down_write(&F2FS_I(inode)->i_sem);
 597         err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
 598         up_write(&F2FS_I(inode)->i_sem);
 599         f2fs_unlock_op(sbi);
 600
 601         return err;
 602 }