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 "f2fs.h"
  25 #include "xattr.h"
  26
  27 static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
  28                 size_t list_size, const char *name, size_t name_len, int type)
  29 {
  30         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  31         int total_len, prefix_len = 0;
  32         const char *prefix = NULL;
  33
  34         switch (type) {
  35         case F2FS_XATTR_INDEX_USER:
  36                 if (!test_opt(sbi, XATTR_USER))
  37                         return -EOPNOTSUPP;
  38                 prefix = XATTR_USER_PREFIX;
  39                 prefix_len = XATTR_USER_PREFIX_LEN;
  40                 break;
  41         case F2FS_XATTR_INDEX_TRUSTED:
  42                 if (!capable(CAP_SYS_ADMIN))
  43                         return -EPERM;
  44                 prefix = XATTR_TRUSTED_PREFIX;
  45                 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  46                 break;
  47         case F2FS_XATTR_INDEX_SECURITY:
  48                 prefix = XATTR_SECURITY_PREFIX;
  49                 prefix_len = XATTR_SECURITY_PREFIX_LEN;
  50                 break;
  51         default:
  52                 return -EINVAL;
  53         }
  54
  55         total_len = prefix_len + name_len + 1;
  56         if (list && total_len <= list_size) {
  57                 memcpy(list, prefix, prefix_len);
  58                 memcpy(list + prefix_len, name, name_len);
  59                 list[prefix_len + name_len] = '\0';
  60         }
  61         return total_len;
  62 }
  63
  64 static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
  65                 void *buffer, size_t size, int type)
  66 {
  67         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  68
  69         switch (type) {
  70         case F2FS_XATTR_INDEX_USER:
  71                 if (!test_opt(sbi, XATTR_USER))
  72                         return -EOPNOTSUPP;
  73                 break;
  74         case F2FS_XATTR_INDEX_TRUSTED:
  75                 if (!capable(CAP_SYS_ADMIN))
  76                         return -EPERM;
  77                 break;
  78         case F2FS_XATTR_INDEX_SECURITY:
  79                 break;
  80         default:
  81                 return -EINVAL;
  82         }
  83         if (strcmp(name, "") == 0)
  84                 return -EINVAL;
  85         return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
  86 }
  87
  88 static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
  89                 const void *value, size_t size, int flags, int type)
  90 {
  91         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
  92
  93         switch (type) {
  94         case F2FS_XATTR_INDEX_USER:
  95                 if (!test_opt(sbi, XATTR_USER))
  96                         return -EOPNOTSUPP;
  97                 break;
  98         case F2FS_XATTR_INDEX_TRUSTED:
  99                 if (!capable(CAP_SYS_ADMIN))
 100                         return -EPERM;
 101                 break;
 102         case F2FS_XATTR_INDEX_SECURITY:
 103                 break;
 104         default:
 105                 return -EINVAL;
 106         }
 107         if (strcmp(name, "") == 0)
 108                 return -EINVAL;
 109
 110         return f2fs_setxattr(dentry->d_inode, type, name, value, size, NULL);
 111 }
 112
 113 static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
 114                 size_t list_size, const char *name, size_t name_len, int type)
 115 {
 116         const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
 117         size_t size;
 118
 119         if (type != F2FS_XATTR_INDEX_ADVISE)
 120                 return 0;
 121
 122         size = strlen(xname) + 1;
 123         if (list && size <= list_size)
 124                 memcpy(list, xname, size);
 125         return size;
 126 }
 127
 128 static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
 129                 void *buffer, size_t size, int type)
 130 {
 131         struct inode *inode = dentry->d_inode;
 132
 133         if (strcmp(name, "") != 0)
 134                 return -EINVAL;
 135
 136         *((char *)buffer) = F2FS_I(inode)->i_advise;
 137         return sizeof(char);
 138 }
 139
 140 static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
 141                 const void *value, size_t size, int flags, int type)
 142 {
 143         struct inode *inode = dentry->d_inode;
 144
 145         if (strcmp(name, "") != 0)
 146                 return -EINVAL;
 147         if (!inode_owner_or_capable(inode))
 148                 return -EPERM;
 149         if (value == NULL)
 150                 return -EINVAL;
 151
 152         F2FS_I(inode)->i_advise |= *(char *)value;
 153         return 0;
 154 }
 155
 156 #ifdef CONFIG_F2FS_FS_SECURITY
 157 static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 158                 void *page)
 159 {
 160         const struct xattr *xattr;
 161         int err = 0;
 162
 163         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
 164                 err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
 165                                 xattr->name, xattr->value,
 166                                 xattr->value_len, (struct page *)page);
 167                 if (err < 0)
 168                         break;
 169         }
 170         return err;
 171 }
 172
 173 int f2fs_init_security(struct inode *inode, struct inode *dir,
 174                                 const struct qstr *qstr, struct page *ipage)
 175 {
 176         return security_inode_init_security(inode, dir, qstr,
 177                                 &f2fs_initxattrs, ipage);
 178 }
 179 #endif
 180
 181 const struct xattr_handler f2fs_xattr_user_handler = {
 182         .prefix = XATTR_USER_PREFIX,
 183         .flags  = F2FS_XATTR_INDEX_USER,
 184         .list   = f2fs_xattr_generic_list,
 185         .get    = f2fs_xattr_generic_get,
 186         .set    = f2fs_xattr_generic_set,
 187 };
 188
 189 const struct xattr_handler f2fs_xattr_trusted_handler = {
 190         .prefix = XATTR_TRUSTED_PREFIX,
 191         .flags  = F2FS_XATTR_INDEX_TRUSTED,
 192         .list   = f2fs_xattr_generic_list,
 193         .get    = f2fs_xattr_generic_get,
 194         .set    = f2fs_xattr_generic_set,
 195 };
 196
 197 const struct xattr_handler f2fs_xattr_advise_handler = {
 198         .prefix = F2FS_SYSTEM_ADVISE_PREFIX,
 199         .flags  = F2FS_XATTR_INDEX_ADVISE,
 200         .list   = f2fs_xattr_advise_list,
 201         .get    = f2fs_xattr_advise_get,
 202         .set    = f2fs_xattr_advise_set,
 203 };
 204
 205 const struct xattr_handler f2fs_xattr_security_handler = {
 206         .prefix = XATTR_SECURITY_PREFIX,
 207         .flags  = F2FS_XATTR_INDEX_SECURITY,
 208         .list   = f2fs_xattr_generic_list,
 209         .get    = f2fs_xattr_generic_get,
 210         .set    = f2fs_xattr_generic_set,
 211 };
 212
 213 static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 214         [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
 215 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 216         [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler,
 217         [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
 218 #endif
 219         [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
 220 #ifdef CONFIG_F2FS_FS_SECURITY
 221         [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
 222 #endif
 223         [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
 224 };
 225
 226 const struct xattr_handler *f2fs_xattr_handlers[] = {
 227         &f2fs_xattr_user_handler,
 228 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 229         &f2fs_xattr_acl_access_handler,
 230         &f2fs_xattr_acl_default_handler,
 231 #endif
 232         &f2fs_xattr_trusted_handler,
 233 #ifdef CONFIG_F2FS_FS_SECURITY
 234         &f2fs_xattr_security_handler,
 235 #endif
 236         &f2fs_xattr_advise_handler,
 237         NULL,
 238 };
 239
 240 static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
 241 {
 242         const struct xattr_handler *handler = NULL;
 243
 244         if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
 245                 handler = f2fs_xattr_handler_map[name_index];
 246         return handler;
 247 }
 248
 249 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int name_index,
 250                                         size_t name_len, const char *name)
 251 {
 252         struct f2fs_xattr_entry *entry;
 253
 254         list_for_each_xattr(entry, base_addr) {
 255                 if (entry->e_name_index != name_index)
 256                         continue;
 257                 if (entry->e_name_len != name_len)
 258                         continue;
 259                 if (!memcmp(entry->e_name, name, name_len))
 260                         break;
 261         }
 262         return entry;
 263 }
 264
 265 static void *read_all_xattrs(struct inode *inode, struct page *ipage)
 266 {
 267         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 268         struct f2fs_xattr_header *header;
 269         size_t size = PAGE_SIZE, inline_size = 0;
 270         void *txattr_addr;
 271
 272         inline_size = inline_xattr_size(inode);
 273
 274         txattr_addr = kzalloc(inline_size + size, GFP_KERNEL);
 275         if (!txattr_addr)
 276                 return NULL;
 277
 278         /* read from inline xattr */
 279         if (inline_size) {
 280                 struct page *page = NULL;
 281                 void *inline_addr;
 282
 283                 if (ipage) {
 284                         inline_addr = inline_xattr_addr(ipage);
 285                 } else {
 286                         page = get_node_page(sbi, inode->i_ino);
 287                         if (IS_ERR(page))
 288                                 goto fail;
 289                         inline_addr = inline_xattr_addr(page);
 290                 }
 291                 memcpy(txattr_addr, inline_addr, inline_size);
 292                 f2fs_put_page(page, 1);
 293         }
 294
 295         /* read from xattr node block */
 296         if (F2FS_I(inode)->i_xattr_nid) {
 297                 struct page *xpage;
 298                 void *xattr_addr;
 299
 300                 /* The inode already has an extended attribute block. */
 301                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 302                 if (IS_ERR(xpage))
 303                         goto fail;
 304
 305                 xattr_addr = page_address(xpage);
 306                 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
 307                 f2fs_put_page(xpage, 1);
 308         }
 309
 310         header = XATTR_HDR(txattr_addr);
 311
 312         /* never been allocated xattrs */
 313         if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
 314                 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
 315                 header->h_refcount = cpu_to_le32(1);
 316         }
 317         return txattr_addr;
 318 fail:
 319         kzfree(txattr_addr);
 320         return NULL;
 321 }
 322
 323 static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
 324                                 void *txattr_addr, struct page *ipage)
 325 {
 326         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 327         size_t inline_size = 0;
 328         void *xattr_addr;
 329         struct page *xpage;
 330         nid_t new_nid = 0;
 331         int err;
 332
 333         inline_size = inline_xattr_size(inode);
 334
 335         if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
 336                 if (!alloc_nid(sbi, &new_nid))
 337                         return -ENOSPC;
 338
 339         /* write to inline xattr */
 340         if (inline_size) {
 341                 struct page *page = NULL;
 342                 void *inline_addr;
 343
 344                 if (ipage) {
 345                         inline_addr = inline_xattr_addr(ipage);
 346                 } else {
 347                         page = get_node_page(sbi, inode->i_ino);
 348                         if (IS_ERR(page)) {
 349                                 alloc_nid_failed(sbi, new_nid);
 350                                 return PTR_ERR(page);
 351                         }
 352                         inline_addr = inline_xattr_addr(page);
 353                 }
 354                 memcpy(inline_addr, txattr_addr, inline_size);
 355                 f2fs_put_page(page, 1);
 356
 357                 /* no need to use xattr node block */
 358                 if (hsize <= inline_size) {
 359                         err = truncate_xattr_node(inode, ipage);
 360                         alloc_nid_failed(sbi, new_nid);
 361                         return err;
 362                 }
 363         }
 364
 365         /* write to xattr node block */
 366         if (F2FS_I(inode)->i_xattr_nid) {
 367                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 368                 if (IS_ERR(xpage)) {
 369                         alloc_nid_failed(sbi, new_nid);
 370                         return PTR_ERR(xpage);
 371                 }
 372                 BUG_ON(new_nid);
 373         } else {
 374                 struct dnode_of_data dn;
 375                 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
 376                 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
 377                 if (IS_ERR(xpage)) {
 378                         alloc_nid_failed(sbi, new_nid);
 379                         return PTR_ERR(xpage);
 380                 }
 381                 alloc_nid_done(sbi, new_nid);
 382         }
 383
 384         xattr_addr = page_address(xpage);
 385         memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
 386                                                 sizeof(struct node_footer));
 387         set_page_dirty(xpage);
 388         f2fs_put_page(xpage, 1);
 389
 390         /* need to checkpoint during fsync */
 391         F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
 392         return 0;
 393 }
 394
 395 int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
 396                 void *buffer, size_t buffer_size)
 397 {
 398         struct f2fs_xattr_entry *entry;
 399         void *base_addr;
 400         int error = 0;
 401         size_t value_len, name_len;
 402
 403         if (name == NULL)
 404                 return -EINVAL;
 405         name_len = strlen(name);
 406
 407         base_addr = read_all_xattrs(inode, NULL);
 408         if (!base_addr)
 409                 return -ENOMEM;
 410
 411         entry = __find_xattr(base_addr, name_index, name_len, name);
 412         if (IS_XATTR_LAST_ENTRY(entry)) {
 413                 error = -ENODATA;
 414                 goto cleanup;
 415         }
 416
 417         value_len = le16_to_cpu(entry->e_value_size);
 418
 419         if (buffer && value_len > buffer_size) {
 420                 error = -ERANGE;
 421                 goto cleanup;
 422         }
 423
 424         if (buffer) {
 425                 char *pval = entry->e_name + entry->e_name_len;
 426                 memcpy(buffer, pval, value_len);
 427         }
 428         error = value_len;
 429
 430 cleanup:
 431         kzfree(base_addr);
 432         return error;
 433 }
 434
 435 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 436 {
 437         struct inode *inode = dentry->d_inode;
 438         struct f2fs_xattr_entry *entry;
 439         void *base_addr;
 440         int error = 0;
 441         size_t rest = buffer_size;
 442
 443         base_addr = read_all_xattrs(inode, NULL);
 444         if (!base_addr)
 445                 return -ENOMEM;
 446
 447         list_for_each_xattr(entry, base_addr) {
 448                 const struct xattr_handler *handler =
 449                         f2fs_xattr_handler(entry->e_name_index);
 450                 size_t size;
 451
 452                 if (!handler)
 453                         continue;
 454
 455                 size = handler->list(dentry, buffer, rest, entry->e_name,
 456                                 entry->e_name_len, handler->flags);
 457                 if (buffer && size > rest) {
 458                         error = -ERANGE;
 459                         goto cleanup;
 460                 }
 461
 462                 if (buffer)
 463                         buffer += size;
 464                 rest -= size;
 465         }
 466         error = buffer_size - rest;
 467 cleanup:
 468         kzfree(base_addr);
 469         return error;
 470 }
 471
 472 int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
 473                         const void *value, size_t value_len, struct page *ipage)
 474 {
 475         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 476         struct f2fs_inode_info *fi = F2FS_I(inode);
 477         struct f2fs_xattr_entry *here, *last;
 478         void *base_addr;
 479         int found, newsize;
 480         size_t name_len;
 481         int ilock;
 482         __u32 new_hsize;
 483         int error = -ENOMEM;
 484
 485         if (name == NULL)
 486                 return -EINVAL;
 487
 488         if (value == NULL)
 489                 value_len = 0;
 490
 491         name_len = strlen(name);
 492
 493         if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode))
 494                 return -ERANGE;
 495
 496         f2fs_balance_fs(sbi);
 497
 498         ilock = mutex_lock_op(sbi);
 499
 500         base_addr = read_all_xattrs(inode, ipage);
 501         if (!base_addr)
 502                 goto exit;
 503
 504         /* find entry with wanted name. */
 505         here = __find_xattr(base_addr, name_index, name_len, name);
 506
 507         found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
 508         last = here;
 509
 510         while (!IS_XATTR_LAST_ENTRY(last))
 511                 last = XATTR_NEXT_ENTRY(last);
 512
 513         newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
 514                         name_len + value_len);
 515
 516         /* 1. Check space */
 517         if (value) {
 518                 int free;
 519                 /*
 520                  * If value is NULL, it is remove operation.
 521                  * In case of update operation, we caculate free.
 522                  */
 523                 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
 524                 if (found)
 525                         free = free - ENTRY_SIZE(here);
 526
 527                 if (free < newsize) {
 528                         error = -ENOSPC;
 529                         goto exit;
 530                 }
 531         }
 532
 533         /* 2. Remove old entry */
 534         if (found) {
 535                 /*
 536                  * If entry is found, remove old entry.
 537                  * If not found, remove operation is not needed.
 538                  */
 539                 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
 540                 int oldsize = ENTRY_SIZE(here);
 541
 542                 memmove(here, next, (char *)last - (char *)next);
 543                 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
 544                 memset(last, 0, oldsize);
 545         }
 546
 547         new_hsize = (char *)last - (char *)base_addr;
 548
 549         /* 3. Write new entry */
 550         if (value) {
 551                 char *pval;
 552                 /*
 553                  * Before we come here, old entry is removed.
 554                  * We just write new entry.
 555                  */
 556                 memset(last, 0, newsize);
 557                 last->e_name_index = name_index;
 558                 last->e_name_len = name_len;
 559                 memcpy(last->e_name, name, name_len);
 560                 pval = last->e_name + name_len;
 561                 memcpy(pval, value, value_len);
 562                 last->e_value_size = cpu_to_le16(value_len);
 563                 new_hsize += newsize;
 564         }
 565
 566         error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
 567         if (error)
 568                 goto exit;
 569
 570         if (is_inode_flag_set(fi, FI_ACL_MODE)) {
 571                 inode->i_mode = fi->i_acl_mode;
 572                 inode->i_ctime = CURRENT_TIME;
 573                 clear_inode_flag(fi, FI_ACL_MODE);
 574         }
 575
 576         if (ipage)
 577                 update_inode(inode, ipage);
 578         else
 579                 update_inode_page(inode);
 580 exit:
 581         mutex_unlock_op(sbi, ilock);
 582         kzfree(base_addr);
 583         return error;
 584 }