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xattr.c
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linux-6.19.14/fs/jfs/xattr.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright (C) International Business Machines Corp., 2000-2004 4 * Copyright (C) Christoph Hellwig, 2002 5 */ 6 7#include <linux/capability.h> 8#include <linux/fs.h> 9#include <linux/xattr.h> 10#include <linux/posix_acl_xattr.h> 11#include <linux/slab.h> 12#include <linux/quotaops.h> 13#include <linux/security.h> 14#include "jfs_incore.h" 15#include "jfs_superblock.h" 16#include "jfs_dmap.h" 17#include "jfs_debug.h" 18#include "jfs_dinode.h" 19#include "jfs_extent.h" 20#include "jfs_metapage.h" 21#include "jfs_xattr.h" 22#include "jfs_acl.h" 23 24/* 25 * jfs_xattr.c: extended attribute service 26 * 27 * Overall design -- 28 * 29 * Format: 30 * 31 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit 32 * value) and a variable (0 or more) number of extended attribute 33 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double 34 * where <name> is constructed from a null-terminated ascii string 35 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data 36 * (1 ... 65535 bytes). The in-memory format is 37 * 38 * 0 1 2 4 4 + namelen + 1 39 * +-------+--------+--------+----------------+-------------------+ 40 * | Flags | Name | Value | Name String \0 | Data . . . . | 41 * | | Length | Length | | | 42 * +-------+--------+--------+----------------+-------------------+ 43 * 44 * A jfs_ea_list then is structured as 45 * 46 * 0 4 4 + EA_SIZE(ea1) 47 * +------------+-------------------+--------------------+----- 48 * | Overall EA | First FEA Element | Second FEA Element | ..... 49 * | List Size | | | 50 * +------------+-------------------+--------------------+----- 51 * 52 * On-disk: 53 * 54 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and 55 * written directly. An EA list may be in-lined in the inode if there is 56 * sufficient room available. 57 */ 58 59struct ea_buffer { 60 int flag; /* Indicates what storage xattr points to */ 61 int max_size; /* largest xattr that fits in current buffer */ 62 dxd_t new_ea; /* dxd to replace ea when modifying xattr */ 63 struct metapage *mp; /* metapage containing ea list */ 64 struct jfs_ea_list *xattr; /* buffer containing ea list */ 65}; 66 67/* 68 * ea_buffer.flag values 69 */ 70#define EA_INLINE 0x0001 71#define EA_EXTENT 0x0002 72#define EA_NEW 0x0004 73#define EA_MALLOC 0x0008 74 75 76/* 77 * Mapping of on-disk attribute names: for on-disk attribute names with an 78 * unknown prefix (not "system.", "user.", "security.", or "trusted."), the 79 * prefix "os2." is prepended. On the way back to disk, "os2." prefixes are 80 * stripped and we make sure that the remaining name does not start with one 81 * of the know prefixes. 82 */ 83 84static int is_known_namespace(const char *name) 85{ 86 if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) && 87 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) && 88 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) && 89 strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) 90 return false; 91 92 return true; 93} 94 95static inline int name_size(struct jfs_ea *ea) 96{ 97 if (is_known_namespace(ea->name)) 98 return ea->namelen; 99 else 100 return ea->namelen + XATTR_OS2_PREFIX_LEN; 101} 102 103static inline int copy_name(char *buffer, struct jfs_ea *ea) 104{ 105 int len = ea->namelen; 106 107 if (!is_known_namespace(ea->name)) { 108 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN); 109 buffer += XATTR_OS2_PREFIX_LEN; 110 len += XATTR_OS2_PREFIX_LEN; 111 } 112 memcpy(buffer, ea->name, ea->namelen); 113 buffer[ea->namelen] = 0; 114 115 return len; 116} 117 118/* Forward references */ 119static void ea_release(struct inode *inode, struct ea_buffer *ea_buf); 120 121/* 122 * NAME: ea_write_inline 123 * 124 * FUNCTION: Attempt to write an EA inline if area is available 125 * 126 * PRE CONDITIONS: 127 * Already verified that the specified EA is small enough to fit inline 128 * 129 * PARAMETERS: 130 * ip - Inode pointer 131 * ealist - EA list pointer 132 * size - size of ealist in bytes 133 * ea - dxd_t structure to be filled in with necessary EA information 134 * if we successfully copy the EA inline 135 * 136 * NOTES: 137 * Checks if the inode's inline area is available. If so, copies EA inline 138 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will 139 * have to be put into an extent. 140 * 141 * RETURNS: 0 for successful copy to inline area; -1 if area not available 142 */ 143static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist, 144 int size, dxd_t * ea) 145{ 146 struct jfs_inode_info *ji = JFS_IP(ip); 147 148 /* 149 * Make sure we have an EA -- the NULL EA list is valid, but you 150 * can't copy it! 151 */ 152 if (ealist && size > sizeof (struct jfs_ea_list)) { 153 assert(size <= sizeof (ji->i_inline_ea)); 154 155 /* 156 * See if the space is available or if it is already being 157 * used for an inline EA. 158 */ 159 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE)) 160 return -EPERM; 161 162 DXDsize(ea, size); 163 DXDlength(ea, 0); 164 DXDaddress(ea, 0); 165 memcpy(ji->i_inline_ea, ealist, size); 166 ea->flag = DXD_INLINE; 167 ji->mode2 &= ~INLINEEA; 168 } else { 169 ea->flag = 0; 170 DXDsize(ea, 0); 171 DXDlength(ea, 0); 172 DXDaddress(ea, 0); 173 174 /* Free up INLINE area */ 175 if (ji->ea.flag & DXD_INLINE) 176 ji->mode2 |= INLINEEA; 177 } 178 179 return 0; 180} 181 182/* 183 * NAME: ea_write 184 * 185 * FUNCTION: Write an EA for an inode 186 * 187 * PRE CONDITIONS: EA has been verified 188 * 189 * PARAMETERS: 190 * ip - Inode pointer 191 * ealist - EA list pointer 192 * size - size of ealist in bytes 193 * ea - dxd_t structure to be filled in appropriately with where the 194 * EA was copied 195 * 196 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an 197 * extent and synchronously writes it to those blocks. 198 * 199 * RETURNS: 0 for success; Anything else indicates failure 200 */ 201static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size, 202 dxd_t * ea) 203{ 204 struct super_block *sb = ip->i_sb; 205 struct jfs_inode_info *ji = JFS_IP(ip); 206 struct jfs_sb_info *sbi = JFS_SBI(sb); 207 int nblocks; 208 s64 blkno; 209 int rc = 0, i; 210 char *cp; 211 s32 nbytes, nb; 212 s32 bytes_to_write; 213 struct metapage *mp; 214 215 /* 216 * Quick check to see if this is an in-linable EA. Short EAs 217 * and empty EAs are all in-linable, provided the space exists. 218 */ 219 if (!ealist || size <= sizeof (ji->i_inline_ea)) { 220 if (!ea_write_inline(ip, ealist, size, ea)) 221 return 0; 222 } 223 224 /* figure out how many blocks we need */ 225 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits; 226 227 /* Allocate new blocks to quota. */ 228 rc = dquot_alloc_block(ip, nblocks); 229 if (rc) 230 return rc; 231 232 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno); 233 if (rc) { 234 /*Rollback quota allocation. */ 235 dquot_free_block(ip, nblocks); 236 return rc; 237 } 238 239 /* 240 * Now have nblocks worth of storage to stuff into the FEALIST. 241 * loop over the FEALIST copying data into the buffer one page at 242 * a time. 243 */ 244 cp = (char *) ealist; 245 nbytes = size; 246 for (i = 0; i < nblocks; i += sbi->nbperpage) { 247 /* 248 * Determine how many bytes for this request, and round up to 249 * the nearest aggregate block size 250 */ 251 nb = min(PSIZE, nbytes); 252 bytes_to_write = 253 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits)) 254 << sb->s_blocksize_bits; 255 256 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) { 257 rc = -EIO; 258 goto failed; 259 } 260 261 memcpy(mp->data, cp, nb); 262 263 /* 264 * We really need a way to propagate errors for 265 * forced writes like this one. --hch 266 * 267 * (__write_metapage => release_metapage => flush_metapage) 268 */ 269#ifdef _JFS_FIXME 270 if ((rc = flush_metapage(mp))) { 271 /* 272 * the write failed -- this means that the buffer 273 * is still assigned and the blocks are not being 274 * used. this seems like the best error recovery 275 * we can get ... 276 */ 277 goto failed; 278 } 279#else 280 flush_metapage(mp); 281#endif 282 283 cp += PSIZE; 284 nbytes -= nb; 285 } 286 287 ea->flag = DXD_EXTENT; 288 DXDsize(ea, le32_to_cpu(ealist->size)); 289 DXDlength(ea, nblocks); 290 DXDaddress(ea, blkno); 291 292 /* Free up INLINE area */ 293 if (ji->ea.flag & DXD_INLINE) 294 ji->mode2 |= INLINEEA; 295 296 return 0; 297 298 failed: 299 /* Rollback quota allocation. */ 300 dquot_free_block(ip, nblocks); 301 302 dbFree(ip, blkno, nblocks); 303 return rc; 304} 305 306/* 307 * NAME: ea_read_inline 308 * 309 * FUNCTION: Read an inlined EA into user's buffer 310 * 311 * PARAMETERS: 312 * ip - Inode pointer 313 * ealist - Pointer to buffer to fill in with EA 314 * 315 * RETURNS: 0 316 */ 317static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist) 318{ 319 struct jfs_inode_info *ji = JFS_IP(ip); 320 int ea_size = sizeDXD(&ji->ea); 321 322 if (ea_size == 0) { 323 ealist->size = 0; 324 return 0; 325 } 326 327 /* Sanity Check */ 328 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea))) 329 return -EIO; 330 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size) 331 != ea_size) 332 return -EIO; 333 334 memcpy(ealist, ji->i_inline_ea, ea_size); 335 return 0; 336} 337 338/* 339 * NAME: ea_read 340 * 341 * FUNCTION: copy EA data into user's buffer 342 * 343 * PARAMETERS: 344 * ip - Inode pointer 345 * ealist - Pointer to buffer to fill in with EA 346 * 347 * NOTES: If EA is inline calls ea_read_inline() to copy EA. 348 * 349 * RETURNS: 0 for success; other indicates failure 350 */ 351static int ea_read(struct inode *ip, struct jfs_ea_list *ealist) 352{ 353 struct super_block *sb = ip->i_sb; 354 struct jfs_inode_info *ji = JFS_IP(ip); 355 struct jfs_sb_info *sbi = JFS_SBI(sb); 356 int nblocks; 357 s64 blkno; 358 char *cp = (char *) ealist; 359 int i; 360 int nbytes, nb; 361 s32 bytes_to_read; 362 struct metapage *mp; 363 364 /* quick check for in-line EA */ 365 if (ji->ea.flag & DXD_INLINE) 366 return ea_read_inline(ip, ealist); 367 368 nbytes = sizeDXD(&ji->ea); 369 if (!nbytes) { 370 jfs_error(sb, "nbytes is 0\n"); 371 return -EIO; 372 } 373 374 /* 375 * Figure out how many blocks were allocated when this EA list was 376 * originally written to disk. 377 */ 378 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage; 379 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage; 380 381 /* 382 * I have found the disk blocks which were originally used to store 383 * the FEALIST. now i loop over each contiguous block copying the 384 * data into the buffer. 385 */ 386 for (i = 0; i < nblocks; i += sbi->nbperpage) { 387 /* 388 * Determine how many bytes for this request, and round up to 389 * the nearest aggregate block size 390 */ 391 nb = min(PSIZE, nbytes); 392 bytes_to_read = 393 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits)) 394 << sb->s_blocksize_bits; 395 396 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1))) 397 return -EIO; 398 399 memcpy(cp, mp->data, nb); 400 release_metapage(mp); 401 402 cp += PSIZE; 403 nbytes -= nb; 404 } 405 406 return 0; 407} 408 409/* 410 * NAME: ea_get 411 * 412 * FUNCTION: Returns buffer containing existing extended attributes. 413 * The size of the buffer will be the larger of the existing 414 * attributes size, or min_size. 415 * 416 * The buffer, which may be inlined in the inode or in the 417 * page cache must be release by calling ea_release or ea_put 418 * 419 * PARAMETERS: 420 * inode - Inode pointer 421 * ea_buf - Structure to be populated with ealist and its metadata 422 * min_size- minimum size of buffer to be returned 423 * 424 * RETURNS: 0 for success; Other indicates failure 425 */ 426static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) 427{ 428 struct jfs_inode_info *ji = JFS_IP(inode); 429 struct super_block *sb = inode->i_sb; 430 int size; 431 int ea_size = sizeDXD(&ji->ea); 432 int blocks_needed, current_blocks; 433 s64 blkno; 434 int rc; 435 int quota_allocation = 0; 436 437 memset(&ea_buf->new_ea, 0, sizeof(ea_buf->new_ea)); 438 439 /* When fsck.jfs clears a bad ea, it doesn't clear the size */ 440 if (ji->ea.flag == 0) 441 ea_size = 0; 442 443 if (ea_size == 0) { 444 if (min_size == 0) { 445 ea_buf->flag = 0; 446 ea_buf->max_size = 0; 447 ea_buf->xattr = NULL; 448 return 0; 449 } 450 if ((min_size <= sizeof (ji->i_inline_ea)) && 451 (ji->mode2 & INLINEEA)) { 452 ea_buf->flag = EA_INLINE | EA_NEW; 453 ea_buf->max_size = sizeof (ji->i_inline_ea); 454 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea; 455 DXDlength(&ea_buf->new_ea, 0); 456 DXDaddress(&ea_buf->new_ea, 0); 457 ea_buf->new_ea.flag = DXD_INLINE; 458 DXDsize(&ea_buf->new_ea, min_size); 459 return 0; 460 } 461 current_blocks = 0; 462 } else if (ji->ea.flag & DXD_INLINE) { 463 if (min_size <= sizeof (ji->i_inline_ea)) { 464 ea_buf->flag = EA_INLINE; 465 ea_buf->max_size = sizeof (ji->i_inline_ea); 466 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea; 467 goto size_check; 468 } 469 current_blocks = 0; 470 } else { 471 if (!(ji->ea.flag & DXD_EXTENT)) { 472 jfs_error(sb, "invalid ea.flag\n"); 473 return -EIO; 474 } 475 current_blocks = (ea_size + sb->s_blocksize - 1) >> 476 sb->s_blocksize_bits; 477 } 478 size = max(min_size, ea_size); 479 480 if (size > PSIZE) { 481 /* 482 * To keep the rest of the code simple. Allocate a 483 * contiguous buffer to work with. Make the buffer large 484 * enough to make use of the whole extent. 485 */ 486 ea_buf->max_size = (size + sb->s_blocksize - 1) & 487 ~(sb->s_blocksize - 1); 488 489 ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL); 490 if (ea_buf->xattr == NULL) 491 return -ENOMEM; 492 493 ea_buf->flag = EA_MALLOC; 494 495 if (ea_size == 0) 496 return 0; 497 498 if ((rc = ea_read(inode, ea_buf->xattr))) { 499 kfree(ea_buf->xattr); 500 ea_buf->xattr = NULL; 501 return rc; 502 } 503 goto size_check; 504 } 505 blocks_needed = (min_size + sb->s_blocksize - 1) >> 506 sb->s_blocksize_bits; 507 508 if (blocks_needed > current_blocks) { 509 /* Allocate new blocks to quota. */ 510 rc = dquot_alloc_block(inode, blocks_needed); 511 if (rc) 512 return -EDQUOT; 513 514 quota_allocation = blocks_needed; 515 516 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed, 517 &blkno); 518 if (rc) 519 goto clean_up; 520 521 DXDlength(&ea_buf->new_ea, blocks_needed); 522 DXDaddress(&ea_buf->new_ea, blkno); 523 ea_buf->new_ea.flag = DXD_EXTENT; 524 DXDsize(&ea_buf->new_ea, min_size); 525 526 ea_buf->flag = EA_EXTENT | EA_NEW; 527 528 ea_buf->mp = get_metapage(inode, blkno, 529 blocks_needed << sb->s_blocksize_bits, 530 1); 531 if (ea_buf->mp == NULL) { 532 dbFree(inode, blkno, (s64) blocks_needed); 533 rc = -EIO; 534 goto clean_up; 535 } 536 ea_buf->xattr = ea_buf->mp->data; 537 ea_buf->max_size = (min_size + sb->s_blocksize - 1) & 538 ~(sb->s_blocksize - 1); 539 if (ea_size == 0) 540 return 0; 541 if ((rc = ea_read(inode, ea_buf->xattr))) { 542 discard_metapage(ea_buf->mp); 543 dbFree(inode, blkno, (s64) blocks_needed); 544 goto clean_up; 545 } 546 goto size_check; 547 } 548 ea_buf->flag = EA_EXTENT; 549 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea), 550 lengthDXD(&ji->ea) << sb->s_blocksize_bits, 551 1); 552 if (ea_buf->mp == NULL) { 553 rc = -EIO; 554 goto clean_up; 555 } 556 ea_buf->xattr = ea_buf->mp->data; 557 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) & 558 ~(sb->s_blocksize - 1); 559 560 size_check: 561 if (EALIST_SIZE(ea_buf->xattr) != ea_size) { 562 if (unlikely(EALIST_SIZE(ea_buf->xattr) > INT_MAX)) { 563 printk(KERN_ERR "ea_get: extended attribute size too large: %u > INT_MAX\n", 564 EALIST_SIZE(ea_buf->xattr)); 565 } else { 566 int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr)); 567 568 printk(KERN_ERR "ea_get: invalid extended attribute\n"); 569 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, 570 ea_buf->xattr, size, 1); 571 } 572 ea_release(inode, ea_buf); 573 rc = -EIO; 574 goto clean_up; 575 } 576 577 return ea_size; 578 579 clean_up: 580 /* Rollback quota allocation */ 581 if (quota_allocation) 582 dquot_free_block(inode, quota_allocation); 583 584 return (rc); 585} 586 587static void ea_release(struct inode *inode, struct ea_buffer *ea_buf) 588{ 589 if (ea_buf->flag & EA_MALLOC) 590 kfree(ea_buf->xattr); 591 else if (ea_buf->flag & EA_EXTENT) { 592 assert(ea_buf->mp); 593 release_metapage(ea_buf->mp); 594 595 if (ea_buf->flag & EA_NEW) 596 dbFree(inode, addressDXD(&ea_buf->new_ea), 597 lengthDXD(&ea_buf->new_ea)); 598 } 599} 600 601static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf, 602 int new_size) 603{ 604 struct jfs_inode_info *ji = JFS_IP(inode); 605 unsigned long old_blocks, new_blocks; 606 int rc = 0; 607 608 if (new_size == 0) { 609 ea_release(inode, ea_buf); 610 ea_buf = NULL; 611 } else if (ea_buf->flag & EA_INLINE) { 612 assert(new_size <= sizeof (ji->i_inline_ea)); 613 ji->mode2 &= ~INLINEEA; 614 ea_buf->new_ea.flag = DXD_INLINE; 615 DXDsize(&ea_buf->new_ea, new_size); 616 DXDaddress(&ea_buf->new_ea, 0); 617 DXDlength(&ea_buf->new_ea, 0); 618 } else if (ea_buf->flag & EA_MALLOC) { 619 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea); 620 kfree(ea_buf->xattr); 621 } else if (ea_buf->flag & EA_NEW) { 622 /* We have already allocated a new dxd */ 623 flush_metapage(ea_buf->mp); 624 } else { 625 /* ->xattr must point to original ea's metapage */ 626 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea); 627 discard_metapage(ea_buf->mp); 628 } 629 if (rc) 630 return rc; 631 632 old_blocks = new_blocks = 0; 633 634 if (ji->ea.flag & DXD_EXTENT) { 635 invalidate_dxd_metapages(inode, ji->ea); 636 old_blocks = lengthDXD(&ji->ea); 637 } 638 639 if (ea_buf) { 640 txEA(tid, inode, &ji->ea, &ea_buf->new_ea); 641 if (ea_buf->new_ea.flag & DXD_EXTENT) { 642 new_blocks = lengthDXD(&ea_buf->new_ea); 643 if (ji->ea.flag & DXD_INLINE) 644 ji->mode2 |= INLINEEA; 645 } 646 ji->ea = ea_buf->new_ea; 647 } else { 648 txEA(tid, inode, &ji->ea, NULL); 649 if (ji->ea.flag & DXD_INLINE) 650 ji->mode2 |= INLINEEA; 651 ji->ea.flag = 0; 652 ji->ea.size = 0; 653 } 654 655 /* If old blocks exist, they must be removed from quota allocation. */ 656 if (old_blocks) 657 dquot_free_block(inode, old_blocks); 658 659 inode_set_ctime_current(inode); 660 661 return 0; 662} 663 664int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name, 665 const void *value, size_t value_len, int flags) 666{ 667 struct jfs_ea_list *ealist; 668 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL; 669 struct ea_buffer ea_buf; 670 int old_ea_size = 0; 671 int xattr_size; 672 int new_size; 673 int namelen = strlen(name); 674 int found = 0; 675 int rc; 676 int length; 677 678 down_write(&JFS_IP(inode)->xattr_sem); 679 680 xattr_size = ea_get(inode, &ea_buf, 0); 681 if (xattr_size < 0) { 682 rc = xattr_size; 683 goto out; 684 } 685 686 again: 687 ealist = (struct jfs_ea_list *) ea_buf.xattr; 688 new_size = sizeof (struct jfs_ea_list); 689 690 if (xattr_size) { 691 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); 692 ea = NEXT_EA(ea)) { 693 if ((namelen == ea->namelen) && 694 (memcmp(name, ea->name, namelen) == 0)) { 695 found = 1; 696 if (flags & XATTR_CREATE) { 697 rc = -EEXIST; 698 goto release; 699 } 700 old_ea = ea; 701 old_ea_size = EA_SIZE(ea); 702 next_ea = NEXT_EA(ea); 703 } else 704 new_size += EA_SIZE(ea); 705 } 706 } 707 708 if (!found) { 709 if (flags & XATTR_REPLACE) { 710 rc = -ENODATA; 711 goto release; 712 } 713 if (value == NULL) { 714 rc = 0; 715 goto release; 716 } 717 } 718 if (value) 719 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len; 720 721 if (new_size > ea_buf.max_size) { 722 /* 723 * We need to allocate more space for merged ea list. 724 * We should only have loop to again: once. 725 */ 726 ea_release(inode, &ea_buf); 727 xattr_size = ea_get(inode, &ea_buf, new_size); 728 if (xattr_size < 0) { 729 rc = xattr_size; 730 goto out; 731 } 732 goto again; 733 } 734 735 /* Remove old ea of the same name */ 736 if (found) { 737 /* number of bytes following target EA */ 738 length = (char *) END_EALIST(ealist) - (char *) next_ea; 739 if (length > 0) 740 memmove(old_ea, next_ea, length); 741 xattr_size -= old_ea_size; 742 } 743 744 /* Add new entry to the end */ 745 if (value) { 746 if (xattr_size == 0) 747 /* Completely new ea list */ 748 xattr_size = sizeof (struct jfs_ea_list); 749 750 /* 751 * The size of EA value is limitted by on-disk format up to 752 * __le16, there would be an overflow if the size is equal 753 * to XATTR_SIZE_MAX (65536). In order to avoid this issue, 754 * we can pre-checkup the value size against USHRT_MAX, and 755 * return -E2BIG in this case, which is consistent with the 756 * VFS setxattr interface. 757 */ 758 if (value_len >= USHRT_MAX) { 759 rc = -E2BIG; 760 goto release; 761 } 762 763 ea = (struct jfs_ea *) ((char *) ealist + xattr_size); 764 ea->flag = 0; 765 ea->namelen = namelen; 766 ea->valuelen = (cpu_to_le16(value_len)); 767 memcpy(ea->name, name, namelen); 768 ea->name[namelen] = 0; 769 if (value_len) 770 memcpy(&ea->name[namelen + 1], value, value_len); 771 xattr_size += EA_SIZE(ea); 772 } 773 774 /* DEBUG - If we did this right, these number match */ 775 if (xattr_size != new_size) { 776 printk(KERN_ERR 777 "__jfs_setxattr: xattr_size = %d, new_size = %d\n", 778 xattr_size, new_size); 779 780 rc = -EINVAL; 781 goto release; 782 } 783 784 /* 785 * If we're left with an empty list, there's no ea 786 */ 787 if (new_size == sizeof (struct jfs_ea_list)) 788 new_size = 0; 789 790 ealist->size = cpu_to_le32(new_size); 791 792 rc = ea_put(tid, inode, &ea_buf, new_size); 793 794 goto out; 795 release: 796 ea_release(inode, &ea_buf); 797 out: 798 up_write(&JFS_IP(inode)->xattr_sem); 799 800 return rc; 801} 802 803ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data, 804 size_t buf_size) 805{ 806 struct jfs_ea_list *ealist; 807 struct jfs_ea *ea, *ealist_end; 808 struct ea_buffer ea_buf; 809 int xattr_size; 810 ssize_t size; 811 int namelen = strlen(name); 812 char *value; 813 814 down_read(&JFS_IP(inode)->xattr_sem); 815 816 xattr_size = ea_get(inode, &ea_buf, 0); 817 818 if (xattr_size < 0) { 819 size = xattr_size; 820 goto out; 821 } 822 823 if (xattr_size == 0) 824 goto not_found; 825 826 ealist = (struct jfs_ea_list *) ea_buf.xattr; 827 ealist_end = END_EALIST(ealist); 828 829 /* Find the named attribute */ 830 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) { 831 if (unlikely(ea + 1 > ealist_end) || 832 unlikely(NEXT_EA(ea) > ealist_end)) { 833 size = -EUCLEAN; 834 goto release; 835 } 836 837 if ((namelen == ea->namelen) && 838 memcmp(name, ea->name, namelen) == 0) { 839 /* Found it */ 840 size = le16_to_cpu(ea->valuelen); 841 if (!data) 842 goto release; 843 else if (size > buf_size) { 844 size = -ERANGE; 845 goto release; 846 } 847 value = ((char *) &ea->name) + ea->namelen + 1; 848 memcpy(data, value, size); 849 goto release; 850 } 851 } 852 not_found: 853 size = -ENODATA; 854 release: 855 ea_release(inode, &ea_buf); 856 out: 857 up_read(&JFS_IP(inode)->xattr_sem); 858 859 return size; 860} 861 862/* 863 * No special permissions are needed to list attributes except for trusted.* 864 */ 865static inline int can_list(struct jfs_ea *ea) 866{ 867 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX, 868 XATTR_TRUSTED_PREFIX_LEN) || 869 capable(CAP_SYS_ADMIN)); 870} 871 872ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size) 873{ 874 struct inode *inode = d_inode(dentry); 875 char *buffer; 876 ssize_t size = 0; 877 int xattr_size; 878 struct jfs_ea_list *ealist; 879 struct jfs_ea *ea, *ealist_end; 880 struct ea_buffer ea_buf; 881 882 down_read(&JFS_IP(inode)->xattr_sem); 883 884 xattr_size = ea_get(inode, &ea_buf, 0); 885 if (xattr_size < 0) { 886 size = xattr_size; 887 goto out; 888 } 889 890 if (xattr_size == 0) 891 goto release; 892 893 ealist = (struct jfs_ea_list *) ea_buf.xattr; 894 ealist_end = END_EALIST(ealist); 895 896 /* compute required size of list */ 897 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) { 898 if (unlikely(ea + 1 > ealist_end) || 899 unlikely(NEXT_EA(ea) > ealist_end)) { 900 size = -EUCLEAN; 901 goto release; 902 } 903 904 if (can_list(ea)) 905 size += name_size(ea) + 1; 906 } 907 908 if (!data) 909 goto release; 910 911 if (size > buf_size) { 912 size = -ERANGE; 913 goto release; 914 } 915 916 /* Copy attribute names to buffer */ 917 buffer = data; 918 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) { 919 if (can_list(ea)) { 920 int namelen = copy_name(buffer, ea); 921 buffer += namelen + 1; 922 } 923 } 924 925 release: 926 ea_release(inode, &ea_buf); 927 out: 928 up_read(&JFS_IP(inode)->xattr_sem); 929 return size; 930} 931 932static int __jfs_xattr_set(struct inode *inode, const char *name, 933 const void *value, size_t size, int flags) 934{ 935 struct jfs_inode_info *ji = JFS_IP(inode); 936 tid_t tid; 937 int rc; 938 939 tid = txBegin(inode->i_sb, 0); 940 mutex_lock(&ji->commit_mutex); 941 rc = __jfs_setxattr(tid, inode, name, value, size, flags); 942 if (!rc) 943 rc = txCommit(tid, 1, &inode, 0); 944 txEnd(tid); 945 mutex_unlock(&ji->commit_mutex); 946 947 return rc; 948} 949 950static int jfs_xattr_get(const struct xattr_handler *handler, 951 struct dentry *unused, struct inode *inode, 952 const char *name, void *value, size_t size) 953{ 954 name = xattr_full_name(handler, name); 955 return __jfs_getxattr(inode, name, value, size); 956} 957 958static int jfs_xattr_set(const struct xattr_handler *handler, 959 struct mnt_idmap *idmap, 960 struct dentry *unused, struct inode *inode, 961 const char *name, const void *value, 962 size_t size, int flags) 963{ 964 name = xattr_full_name(handler, name); 965 return __jfs_xattr_set(inode, name, value, size, flags); 966} 967 968static int jfs_xattr_get_os2(const struct xattr_handler *handler, 969 struct dentry *unused, struct inode *inode, 970 const char *name, void *value, size_t size) 971{ 972 if (is_known_namespace(name)) 973 return -EOPNOTSUPP; 974 return __jfs_getxattr(inode, name, value, size); 975} 976 977static int jfs_xattr_set_os2(const struct xattr_handler *handler, 978 struct mnt_idmap *idmap, 979 struct dentry *unused, struct inode *inode, 980 const char *name, const void *value, 981 size_t size, int flags) 982{ 983 if (is_known_namespace(name)) 984 return -EOPNOTSUPP; 985 return __jfs_xattr_set(inode, name, value, size, flags); 986} 987 988static const struct xattr_handler jfs_user_xattr_handler = { 989 .prefix = XATTR_USER_PREFIX, 990 .get = jfs_xattr_get, 991 .set = jfs_xattr_set, 992}; 993 994static const struct xattr_handler jfs_os2_xattr_handler = { 995 .prefix = XATTR_OS2_PREFIX, 996 .get = jfs_xattr_get_os2, 997 .set = jfs_xattr_set_os2, 998}; 999 1000static const struct xattr_handler jfs_security_xattr_handler = { 1001 .prefix = XATTR_SECURITY_PREFIX, 1002 .get = jfs_xattr_get, 1003 .set = jfs_xattr_set, 1004}; 1005 1006static const struct xattr_handler jfs_trusted_xattr_handler = { 1007 .prefix = XATTR_TRUSTED_PREFIX, 1008 .get = jfs_xattr_get, 1009 .set = jfs_xattr_set, 1010}; 1011 1012const struct xattr_handler * const jfs_xattr_handlers[] = { 1013 &jfs_os2_xattr_handler, 1014 &jfs_user_xattr_handler, 1015 &jfs_security_xattr_handler, 1016 &jfs_trusted_xattr_handler, 1017 NULL, 1018}; 1019 1020 1021#ifdef CONFIG_JFS_SECURITY 1022static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array, 1023 void *fs_info) 1024{ 1025 const struct xattr *xattr; 1026 tid_t *tid = fs_info; 1027 char *name; 1028 int err = 0; 1029 1030 for (xattr = xattr_array; xattr->name != NULL; xattr++) { 1031 name = kmalloc(XATTR_SECURITY_PREFIX_LEN + 1032 strlen(xattr->name) + 1, GFP_NOFS); 1033 if (!name) { 1034 err = -ENOMEM; 1035 break; 1036 } 1037 strcpy(name, XATTR_SECURITY_PREFIX); 1038 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); 1039 1040 err = __jfs_setxattr(*tid, inode, name, 1041 xattr->value, xattr->value_len, 0); 1042 kfree(name); 1043 if (err < 0) 1044 break; 1045 } 1046 return err; 1047} 1048 1049int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir, 1050 const struct qstr *qstr) 1051{ 1052 return security_inode_init_security(inode, dir, qstr, 1053 &jfs_initxattrs, &tid); 1054} 1055#endif
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