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_setxattr(struct inode *inode, int name_index,
 158                         const char *name, const void *value, size_t value_len,
 159                         struct page *ipage);
 160 static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
 161                 void *page)
 162 {
 163         const struct xattr *xattr;
 164         int err = 0;
 165
 166         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
 167                 err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
 168                                 xattr->name, xattr->value,
 169                                 xattr->value_len, (struct page *)page);
 170                 if (err < 0)
 171                         break;
 172         }
 173         return err;
 174 }
 175
 176 int f2fs_init_security(struct inode *inode, struct inode *dir,
 177                                 const struct qstr *qstr, struct page *ipage)
 178 {
 179         return security_inode_init_security(inode, dir, qstr,
 180                                 &f2fs_initxattrs, ipage);
 181 }
 182 #endif
 183
 184 const struct xattr_handler f2fs_xattr_user_handler = {
 185         .prefix = XATTR_USER_PREFIX,
 186         .flags  = F2FS_XATTR_INDEX_USER,
 187         .list   = f2fs_xattr_generic_list,
 188         .get    = f2fs_xattr_generic_get,
 189         .set    = f2fs_xattr_generic_set,
 190 };
 191
 192 const struct xattr_handler f2fs_xattr_trusted_handler = {
 193         .prefix = XATTR_TRUSTED_PREFIX,
 194         .flags  = F2FS_XATTR_INDEX_TRUSTED,
 195         .list   = f2fs_xattr_generic_list,
 196         .get    = f2fs_xattr_generic_get,
 197         .set    = f2fs_xattr_generic_set,
 198 };
 199
 200 const struct xattr_handler f2fs_xattr_advise_handler = {
 201         .prefix = F2FS_SYSTEM_ADVISE_PREFIX,
 202         .flags  = F2FS_XATTR_INDEX_ADVISE,
 203         .list   = f2fs_xattr_advise_list,
 204         .get    = f2fs_xattr_advise_get,
 205         .set    = f2fs_xattr_advise_set,
 206 };
 207
 208 const struct xattr_handler f2fs_xattr_security_handler = {
 209         .prefix = XATTR_SECURITY_PREFIX,
 210         .flags  = F2FS_XATTR_INDEX_SECURITY,
 211         .list   = f2fs_xattr_generic_list,
 212         .get    = f2fs_xattr_generic_get,
 213         .set    = f2fs_xattr_generic_set,
 214 };
 215
 216 static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 217         [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
 218 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 219         [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler,
 220         [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
 221 #endif
 222         [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
 223 #ifdef CONFIG_F2FS_FS_SECURITY
 224         [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
 225 #endif
 226         [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
 227 };
 228
 229 const struct xattr_handler *f2fs_xattr_handlers[] = {
 230         &f2fs_xattr_user_handler,
 231 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 232         &f2fs_xattr_acl_access_handler,
 233         &f2fs_xattr_acl_default_handler,
 234 #endif
 235         &f2fs_xattr_trusted_handler,
 236 #ifdef CONFIG_F2FS_FS_SECURITY
 237         &f2fs_xattr_security_handler,
 238 #endif
 239         &f2fs_xattr_advise_handler,
 240         NULL,
 241 };
 242
 243 static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
 244 {
 245         const struct xattr_handler *handler = NULL;
 246
 247         if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
 248                 handler = f2fs_xattr_handler_map[name_index];
 249         return handler;
 250 }
 251
 252 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int name_index,
 253                                         size_t name_len, const char *name)
 254 {
 255         struct f2fs_xattr_entry *entry;
 256
 257         list_for_each_xattr(entry, base_addr) {
 258                 if (entry->e_name_index != name_index)
 259                         continue;
 260                 if (entry->e_name_len != name_len)
 261                         continue;
 262                 if (!memcmp(entry->e_name, name, name_len))
 263                         break;
 264         }
 265         return entry;
 266 }
 267
 268 static void *read_all_xattrs(struct inode *inode, struct page *ipage)
 269 {
 270         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 271         struct f2fs_xattr_header *header;
 272         size_t size = PAGE_SIZE, inline_size = 0;
 273         void *txattr_addr;
 274
 275         inline_size = inline_xattr_size(inode);
 276
 277         txattr_addr = kzalloc(inline_size + size, GFP_KERNEL);
 278         if (!txattr_addr)
 279                 return NULL;
 280
 281         /* read from inline xattr */
 282         if (inline_size) {
 283                 struct page *page = NULL;
 284                 void *inline_addr;
 285
 286                 if (ipage) {
 287                         inline_addr = inline_xattr_addr(ipage);
 288                 } else {
 289                         page = get_node_page(sbi, inode->i_ino);
 290                         if (IS_ERR(page))
 291                                 goto fail;
 292                         inline_addr = inline_xattr_addr(page);
 293                 }
 294                 memcpy(txattr_addr, inline_addr, inline_size);
 295                 f2fs_put_page(page, 1);
 296         }
 297
 298         /* read from xattr node block */
 299         if (F2FS_I(inode)->i_xattr_nid) {
 300                 struct page *xpage;
 301                 void *xattr_addr;
 302
 303                 /* The inode already has an extended attribute block. */
 304                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 305                 if (IS_ERR(xpage))
 306                         goto fail;
 307
 308                 xattr_addr = page_address(xpage);
 309                 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
 310                 f2fs_put_page(xpage, 1);
 311         }
 312
 313         header = XATTR_HDR(txattr_addr);
 314
 315         /* never been allocated xattrs */
 316         if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
 317                 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
 318                 header->h_refcount = cpu_to_le32(1);
 319         }
 320         return txattr_addr;
 321 fail:
 322         kzfree(txattr_addr);
 323         return NULL;
 324 }
 325
 326 static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
 327                                 void *txattr_addr, struct page *ipage)
 328 {
 329         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 330         size_t inline_size = 0;
 331         void *xattr_addr;
 332         struct page *xpage;
 333         nid_t new_nid = 0;
 334         int err;
 335
 336         inline_size = inline_xattr_size(inode);
 337
 338         if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
 339                 if (!alloc_nid(sbi, &new_nid))
 340                         return -ENOSPC;
 341
 342         /* write to inline xattr */
 343         if (inline_size) {
 344                 struct page *page = NULL;
 345                 void *inline_addr;
 346
 347                 if (ipage) {
 348                         inline_addr = inline_xattr_addr(ipage);
 349                 } else {
 350                         page = get_node_page(sbi, inode->i_ino);
 351                         if (IS_ERR(page)) {
 352                                 alloc_nid_failed(sbi, new_nid);
 353                                 return PTR_ERR(page);
 354                         }
 355                         inline_addr = inline_xattr_addr(page);
 356                 }
 357                 memcpy(inline_addr, txattr_addr, inline_size);
 358                 f2fs_put_page(page, 1);
 359
 360                 /* no need to use xattr node block */
 361                 if (hsize <= inline_size) {
 362                         err = truncate_xattr_node(inode, ipage);
 363                         alloc_nid_failed(sbi, new_nid);
 364                         return err;
 365                 }
 366         }
 367
 368         /* write to xattr node block */
 369         if (F2FS_I(inode)->i_xattr_nid) {
 370                 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
 371                 if (IS_ERR(xpage)) {
 372                         alloc_nid_failed(sbi, new_nid);
 373                         return PTR_ERR(xpage);
 374                 }
 375                 f2fs_bug_on(new_nid);
 376         } else {
 377                 struct dnode_of_data dn;
 378                 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
 379                 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
 380                 if (IS_ERR(xpage)) {
 381                         alloc_nid_failed(sbi, new_nid);
 382                         return PTR_ERR(xpage);
 383                 }
 384                 alloc_nid_done(sbi, new_nid);
 385         }
 386
 387         xattr_addr = page_address(xpage);
 388         memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
 389                                                 sizeof(struct node_footer));
 390         set_page_dirty(xpage);
 391         f2fs_put_page(xpage, 1);
 392
 393         /* need to checkpoint during fsync */
 394         F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
 395         return 0;
 396 }
 397
 398 int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
 399                 void *buffer, size_t buffer_size)
 400 {
 401         struct f2fs_xattr_entry *entry;
 402         void *base_addr;
 403         int error = 0;
 404         size_t value_len, name_len;
 405
 406         if (name == NULL)
 407                 return -EINVAL;
 408         name_len = strlen(name);
 409
 410         base_addr = read_all_xattrs(inode, NULL);
 411         if (!base_addr)
 412                 return -ENOMEM;
 413
 414         entry = __find_xattr(base_addr, name_index, name_len, name);
 415         if (IS_XATTR_LAST_ENTRY(entry)) {
 416                 error = -ENODATA;
 417                 goto cleanup;
 418         }
 419
 420         value_len = le16_to_cpu(entry->e_value_size);
 421
 422         if (buffer && value_len > buffer_size) {
 423                 error = -ERANGE;
 424                 goto cleanup;
 425         }
 426
 427         if (buffer) {
 428                 char *pval = entry->e_name + entry->e_name_len;
 429                 memcpy(buffer, pval, value_len);
 430         }
 431         error = value_len;
 432
 433 cleanup:
 434         kzfree(base_addr);
 435         return error;
 436 }
 437
 438 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 439 {
 440         struct inode *inode = dentry->d_inode;
 441         struct f2fs_xattr_entry *entry;
 442         void *base_addr;
 443         int error = 0;
 444         size_t rest = buffer_size;
 445
 446         base_addr = read_all_xattrs(inode, NULL);
 447         if (!base_addr)
 448                 return -ENOMEM;
 449
 450         list_for_each_xattr(entry, base_addr) {
 451                 const struct xattr_handler *handler =
 452                         f2fs_xattr_handler(entry->e_name_index);
 453                 size_t size;
 454
 455                 if (!handler)
 456                         continue;
 457
 458                 size = handler->list(dentry, buffer, rest, entry->e_name,
 459                                 entry->e_name_len, handler->flags);
 460                 if (buffer && size > rest) {
 461                         error = -ERANGE;
 462                         goto cleanup;
 463                 }
 464
 465                 if (buffer)
 466                         buffer += size;
 467                 rest -= size;
 468         }
 469         error = buffer_size - rest;
 470 cleanup:
 471         kzfree(base_addr);
 472         return error;
 473 }
 474
 475 static int __f2fs_setxattr(struct inode *inode, int name_index,
 476                         const char *name, const void *value, size_t value_len,
 477                         struct page *ipage)
 478 {
 479         struct f2fs_inode_info *fi = F2FS_I(inode);
 480         struct f2fs_xattr_entry *here, *last;
 481         void *base_addr;
 482         int found, newsize;
 483         size_t name_len;
 484         __u32 new_hsize;
 485         int error = -ENOMEM;
 486
 487         if (name == NULL)
 488                 return -EINVAL;
 489
 490         if (value == NULL)
 491                 value_len = 0;
 492
 493         name_len = strlen(name);
 494
 495         if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode))
 496                 return -ERANGE;
 497
 498         base_addr = read_all_xattrs(inode, ipage);
 499         if (!base_addr)
 500                 goto exit;
 501
 502         /* find entry with wanted name. */
 503         here = __find_xattr(base_addr, name_index, name_len, name);
 504
 505         found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
 506         last = here;
 507
 508         while (!IS_XATTR_LAST_ENTRY(last))
 509                 last = XATTR_NEXT_ENTRY(last);
 510
 511         newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
 512                         name_len + value_len);
 513
 514         /* 1. Check space */
 515         if (value) {
 516                 int free;
 517                 /*
 518                  * If value is NULL, it is remove operation.
 519                  * In case of update operation, we caculate free.
 520                  */
 521                 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
 522                 if (found)
 523                         free = free + ENTRY_SIZE(here);
 524
 525                 if (free < newsize) {
 526                         error = -ENOSPC;
 527                         goto exit;
 528                 }
 529         }
 530
 531         /* 2. Remove old entry */
 532         if (found) {
 533                 /*
 534                  * If entry is found, remove old entry.
 535                  * If not found, remove operation is not needed.
 536                  */
 537                 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
 538                 int oldsize = ENTRY_SIZE(here);
 539
 540                 memmove(here, next, (char *)last - (char *)next);
 541                 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
 542                 memset(last, 0, oldsize);
 543         }
 544
 545         new_hsize = (char *)last - (char *)base_addr;
 546
 547         /* 3. Write new entry */
 548         if (value) {
 549                 char *pval;
 550                 /*
 551                  * Before we come here, old entry is removed.
 552                  * We just write new entry.
 553                  */
 554                 memset(last, 0, newsize);
 555                 last->e_name_index = name_index;
 556                 last->e_name_len = name_len;
 557                 memcpy(last->e_name, name, name_len);
 558                 pval = last->e_name + name_len;
 559                 memcpy(pval, value, value_len);
 560                 last->e_value_size = cpu_to_le16(value_len);
 561                 new_hsize += newsize;
 562         }
 563
 564         error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
 565         if (error)
 566                 goto exit;
 567
 568         if (is_inode_flag_set(fi, FI_ACL_MODE)) {
 569                 inode->i_mode = fi->i_acl_mode;
 570                 inode->i_ctime = CURRENT_TIME;
 571                 clear_inode_flag(fi, FI_ACL_MODE);
 572         }
 573
 574         if (ipage)
 575                 update_inode(inode, ipage);
 576         else
 577                 update_inode_page(inode);
 578 exit:
 579         kzfree(base_addr);
 580         return error;
 581 }
 582
 583 int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
 584                         const void *value, size_t value_len, struct page *ipage)
 585 {
 586         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 587         int err;
 588
 589         f2fs_balance_fs(sbi);
 590
 591         f2fs_lock_op(sbi);
 592         err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
 593         f2fs_unlock_op(sbi);
 594
 595         return err;
 596 }