fs/jfs/xattr.c

   1 /*
   2  *   Copyright (C) International Business Machines  Corp., 2000-2004
   3  *   Copyright (C) Christoph Hellwig, 2002
   4  *
   5  *   This program is free software;  you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *   the GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program;  if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 #include <linux/capability.h>
  21 #include <linux/fs.h>
  22 #include <linux/xattr.h>
  23 #include <linux/posix_acl_xattr.h>
  24 #include <linux/quotaops.h>
  25 #include <linux/security.h>
  26 #include "jfs_incore.h"
  27 #include "jfs_superblock.h"
  28 #include "jfs_dmap.h"
  29 #include "jfs_debug.h"
  30 #include "jfs_dinode.h"
  31 #include "jfs_extent.h"
  32 #include "jfs_metapage.h"
  33 #include "jfs_xattr.h"
  34 #include "jfs_acl.h"
  35
  36 /*
  37  *      jfs_xattr.c: extended attribute service
  38  *
  39  * Overall design --
  40  *
  41  * Format:
  42  *
  43  *   Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
  44  *   value) and a variable (0 or more) number of extended attribute
  45  *   entries.  Each extended attribute entry (jfs_ea) is a <name,value> double
  46  *   where <name> is constructed from a null-terminated ascii string
  47  *   (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
  48  *   (1 ... 65535 bytes).  The in-memory format is
  49  *
  50  *   0       1        2        4                4 + namelen + 1
  51  *   +-------+--------+--------+----------------+-------------------+
  52  *   | Flags | Name   | Value  | Name String \0 | Data . . . .      |
  53  *   |       | Length | Length |                |                   |
  54  *   +-------+--------+--------+----------------+-------------------+
  55  *
  56  *   A jfs_ea_list then is structured as
  57  *
  58  *   0            4                   4 + EA_SIZE(ea1)
  59  *   +------------+-------------------+--------------------+-----
  60  *   | Overall EA | First FEA Element | Second FEA Element | .....
  61  *   | List Size  |                   |                    |
  62  *   +------------+-------------------+--------------------+-----
  63  *
  64  *   On-disk:
  65  *
  66  *      FEALISTs are stored on disk using blocks allocated by dbAlloc() and
  67  *      written directly. An EA list may be in-lined in the inode if there is
  68  *      sufficient room available.
  69  */
  70
  71 struct ea_buffer {
  72         int flag;               /* Indicates what storage xattr points to */
  73         int max_size;           /* largest xattr that fits in current buffer */
  74         dxd_t new_ea;           /* dxd to replace ea when modifying xattr */
  75         struct metapage *mp;    /* metapage containing ea list */
  76         struct jfs_ea_list *xattr;      /* buffer containing ea list */
  77 };
  78
  79 /*
  80  * ea_buffer.flag values
  81  */
  82 #define EA_INLINE       0x0001
  83 #define EA_EXTENT       0x0002
  84 #define EA_NEW          0x0004
  85 #define EA_MALLOC       0x0008
  86
  87
  88 /*
  89  * These three routines are used to recognize on-disk extended attributes
  90  * that are in a recognized namespace.  If the attribute is not recognized,
  91  * "os2." is prepended to the name
  92  */
  93 static inline int is_os2_xattr(struct jfs_ea *ea)
  94 {
  95         /*
  96          * Check for "system."
  97          */
  98         if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
  99             !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 100                 return false;
 101         /*
 102          * Check for "user."
 103          */
 104         if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
 105             !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
 106                 return false;
 107         /*
 108          * Check for "security."
 109          */
 110         if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
 111             !strncmp(ea->name, XATTR_SECURITY_PREFIX,
 112                      XATTR_SECURITY_PREFIX_LEN))
 113                 return false;
 114         /*
 115          * Check for "trusted."
 116          */
 117         if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
 118             !strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
 119                 return false;
 120         /*
 121          * Add any other valid namespace prefixes here
 122          */
 123
 124         /*
 125          * We assume it's OS/2's flat namespace
 126          */
 127         return true;
 128 }
 129
 130 static inline int name_size(struct jfs_ea *ea)
 131 {
 132         if (is_os2_xattr(ea))
 133                 return ea->namelen + XATTR_OS2_PREFIX_LEN;
 134         else
 135                 return ea->namelen;
 136 }
 137
 138 static inline int copy_name(char *buffer, struct jfs_ea *ea)
 139 {
 140         int len = ea->namelen;
 141
 142         if (is_os2_xattr(ea)) {
 143                 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
 144                 buffer += XATTR_OS2_PREFIX_LEN;
 145                 len += XATTR_OS2_PREFIX_LEN;
 146         }
 147         memcpy(buffer, ea->name, ea->namelen);
 148         buffer[ea->namelen] = 0;
 149
 150         return len;
 151 }
 152
 153 /* Forward references */
 154 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
 155
 156 /*
 157  * NAME: ea_write_inline
 158  *
 159  * FUNCTION: Attempt to write an EA inline if area is available
 160  *
 161  * PRE CONDITIONS:
 162  *      Already verified that the specified EA is small enough to fit inline
 163  *
 164  * PARAMETERS:
 165  *      ip      - Inode pointer
 166  *      ealist  - EA list pointer
 167  *      size    - size of ealist in bytes
 168  *      ea      - dxd_t structure to be filled in with necessary EA information
 169  *                if we successfully copy the EA inline
 170  *
 171  * NOTES:
 172  *      Checks if the inode's inline area is available.  If so, copies EA inline
 173  *      and sets <ea> fields appropriately.  Otherwise, returns failure, EA will
 174  *      have to be put into an extent.
 175  *
 176  * RETURNS: 0 for successful copy to inline area; -1 if area not available
 177  */
 178 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
 179                            int size, dxd_t * ea)
 180 {
 181         struct jfs_inode_info *ji = JFS_IP(ip);
 182
 183         /*
 184          * Make sure we have an EA -- the NULL EA list is valid, but you
 185          * can't copy it!
 186          */
 187         if (ealist && size > sizeof (struct jfs_ea_list)) {
 188                 assert(size <= sizeof (ji->i_inline_ea));
 189
 190                 /*
 191                  * See if the space is available or if it is already being
 192                  * used for an inline EA.
 193                  */
 194                 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
 195                         return -EPERM;
 196
 197                 DXDsize(ea, size);
 198                 DXDlength(ea, 0);
 199                 DXDaddress(ea, 0);
 200                 memcpy(ji->i_inline_ea, ealist, size);
 201                 ea->flag = DXD_INLINE;
 202                 ji->mode2 &= ~INLINEEA;
 203         } else {
 204                 ea->flag = 0;
 205                 DXDsize(ea, 0);
 206                 DXDlength(ea, 0);
 207                 DXDaddress(ea, 0);
 208
 209                 /* Free up INLINE area */
 210                 if (ji->ea.flag & DXD_INLINE)
 211                         ji->mode2 |= INLINEEA;
 212         }
 213
 214         return 0;
 215 }
 216
 217 /*
 218  * NAME: ea_write
 219  *
 220  * FUNCTION: Write an EA for an inode
 221  *
 222  * PRE CONDITIONS: EA has been verified
 223  *
 224  * PARAMETERS:
 225  *      ip      - Inode pointer
 226  *      ealist  - EA list pointer
 227  *      size    - size of ealist in bytes
 228  *      ea      - dxd_t structure to be filled in appropriately with where the
 229  *                EA was copied
 230  *
 231  * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
 232  *      extent and synchronously writes it to those blocks.
 233  *
 234  * RETURNS: 0 for success; Anything else indicates failure
 235  */
 236 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
 237                        dxd_t * ea)
 238 {
 239         struct super_block *sb = ip->i_sb;
 240         struct jfs_inode_info *ji = JFS_IP(ip);
 241         struct jfs_sb_info *sbi = JFS_SBI(sb);
 242         int nblocks;
 243         s64 blkno;
 244         int rc = 0, i;
 245         char *cp;
 246         s32 nbytes, nb;
 247         s32 bytes_to_write;
 248         struct metapage *mp;
 249
 250         /*
 251          * Quick check to see if this is an in-linable EA.  Short EAs
 252          * and empty EAs are all in-linable, provided the space exists.
 253          */
 254         if (!ealist || size <= sizeof (ji->i_inline_ea)) {
 255                 if (!ea_write_inline(ip, ealist, size, ea))
 256                         return 0;
 257         }
 258
 259         /* figure out how many blocks we need */
 260         nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
 261
 262         /* Allocate new blocks to quota. */
 263         if (vfs_dq_alloc_block(ip, nblocks)) {
 264                 return -EDQUOT;
 265         }
 266
 267         rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
 268         if (rc) {
 269                 /*Rollback quota allocation. */
 270                 vfs_dq_free_block(ip, nblocks);
 271                 return rc;
 272         }
 273
 274         /*
 275          * Now have nblocks worth of storage to stuff into the FEALIST.
 276          * loop over the FEALIST copying data into the buffer one page at
 277          * a time.
 278          */
 279         cp = (char *) ealist;
 280         nbytes = size;
 281         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 282                 /*
 283                  * Determine how many bytes for this request, and round up to
 284                  * the nearest aggregate block size
 285                  */
 286                 nb = min(PSIZE, nbytes);
 287                 bytes_to_write =
 288                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 289                     << sb->s_blocksize_bits;
 290
 291                 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
 292                         rc = -EIO;
 293                         goto failed;
 294                 }
 295
 296                 memcpy(mp->data, cp, nb);
 297
 298                 /*
 299                  * We really need a way to propagate errors for
 300                  * forced writes like this one.  --hch
 301                  *
 302                  * (__write_metapage => release_metapage => flush_metapage)
 303                  */
 304 #ifdef _JFS_FIXME
 305                 if ((rc = flush_metapage(mp))) {
 306                         /*
 307                          * the write failed -- this means that the buffer
 308                          * is still assigned and the blocks are not being
 309                          * used.  this seems like the best error recovery
 310                          * we can get ...
 311                          */
 312                         goto failed;
 313                 }
 314 #else
 315                 flush_metapage(mp);
 316 #endif
 317
 318                 cp += PSIZE;
 319                 nbytes -= nb;
 320         }
 321
 322         ea->flag = DXD_EXTENT;
 323         DXDsize(ea, le32_to_cpu(ealist->size));
 324         DXDlength(ea, nblocks);
 325         DXDaddress(ea, blkno);
 326
 327         /* Free up INLINE area */
 328         if (ji->ea.flag & DXD_INLINE)
 329                 ji->mode2 |= INLINEEA;
 330
 331         return 0;
 332
 333       failed:
 334         /* Rollback quota allocation. */
 335         vfs_dq_free_block(ip, nblocks);
 336
 337         dbFree(ip, blkno, nblocks);
 338         return rc;
 339 }
 340
 341 /*
 342  * NAME: ea_read_inline
 343  *
 344  * FUNCTION: Read an inlined EA into user's buffer
 345  *
 346  * PARAMETERS:
 347  *      ip      - Inode pointer
 348  *      ealist  - Pointer to buffer to fill in with EA
 349  *
 350  * RETURNS: 0
 351  */
 352 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
 353 {
 354         struct jfs_inode_info *ji = JFS_IP(ip);
 355         int ea_size = sizeDXD(&ji->ea);
 356
 357         if (ea_size == 0) {
 358                 ealist->size = 0;
 359                 return 0;
 360         }
 361
 362         /* Sanity Check */
 363         if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
 364                 return -EIO;
 365         if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
 366             != ea_size)
 367                 return -EIO;
 368
 369         memcpy(ealist, ji->i_inline_ea, ea_size);
 370         return 0;
 371 }
 372
 373 /*
 374  * NAME: ea_read
 375  *
 376  * FUNCTION: copy EA data into user's buffer
 377  *
 378  * PARAMETERS:
 379  *      ip      - Inode pointer
 380  *      ealist  - Pointer to buffer to fill in with EA
 381  *
 382  * NOTES:  If EA is inline calls ea_read_inline() to copy EA.
 383  *
 384  * RETURNS: 0 for success; other indicates failure
 385  */
 386 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
 387 {
 388         struct super_block *sb = ip->i_sb;
 389         struct jfs_inode_info *ji = JFS_IP(ip);
 390         struct jfs_sb_info *sbi = JFS_SBI(sb);
 391         int nblocks;
 392         s64 blkno;
 393         char *cp = (char *) ealist;
 394         int i;
 395         int nbytes, nb;
 396         s32 bytes_to_read;
 397         struct metapage *mp;
 398
 399         /* quick check for in-line EA */
 400         if (ji->ea.flag & DXD_INLINE)
 401                 return ea_read_inline(ip, ealist);
 402
 403         nbytes = sizeDXD(&ji->ea);
 404         if (!nbytes) {
 405                 jfs_error(sb, "ea_read: nbytes is 0");
 406                 return -EIO;
 407         }
 408
 409         /*
 410          * Figure out how many blocks were allocated when this EA list was
 411          * originally written to disk.
 412          */
 413         nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
 414         blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
 415
 416         /*
 417          * I have found the disk blocks which were originally used to store
 418          * the FEALIST.  now i loop over each contiguous block copying the
 419          * data into the buffer.
 420          */
 421         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 422                 /*
 423                  * Determine how many bytes for this request, and round up to
 424                  * the nearest aggregate block size
 425                  */
 426                 nb = min(PSIZE, nbytes);
 427                 bytes_to_read =
 428                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 429                     << sb->s_blocksize_bits;
 430
 431                 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
 432                         return -EIO;
 433
 434                 memcpy(cp, mp->data, nb);
 435                 release_metapage(mp);
 436
 437                 cp += PSIZE;
 438                 nbytes -= nb;
 439         }
 440
 441         return 0;
 442 }
 443
 444 /*
 445  * NAME: ea_get
 446  *
 447  * FUNCTION: Returns buffer containing existing extended attributes.
 448  *           The size of the buffer will be the larger of the existing
 449  *           attributes size, or min_size.
 450  *
 451  *           The buffer, which may be inlined in the inode or in the
 452  *           page cache must be release by calling ea_release or ea_put
 453  *
 454  * PARAMETERS:
 455  *      inode   - Inode pointer
 456  *      ea_buf  - Structure to be populated with ealist and its metadata
 457  *      min_size- minimum size of buffer to be returned
 458  *
 459  * RETURNS: 0 for success; Other indicates failure
 460  */
 461 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
 462 {
 463         struct jfs_inode_info *ji = JFS_IP(inode);
 464         struct super_block *sb = inode->i_sb;
 465         int size;
 466         int ea_size = sizeDXD(&ji->ea);
 467         int blocks_needed, current_blocks;
 468         s64 blkno;
 469         int rc;
 470         int quota_allocation = 0;
 471
 472         /* When fsck.jfs clears a bad ea, it doesn't clear the size */
 473         if (ji->ea.flag == 0)
 474                 ea_size = 0;
 475
 476         if (ea_size == 0) {
 477                 if (min_size == 0) {
 478                         ea_buf->flag = 0;
 479                         ea_buf->max_size = 0;
 480                         ea_buf->xattr = NULL;
 481                         return 0;
 482                 }
 483                 if ((min_size <= sizeof (ji->i_inline_ea)) &&
 484                     (ji->mode2 & INLINEEA)) {
 485                         ea_buf->flag = EA_INLINE | EA_NEW;
 486                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 487                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 488                         DXDlength(&ea_buf->new_ea, 0);
 489                         DXDaddress(&ea_buf->new_ea, 0);
 490                         ea_buf->new_ea.flag = DXD_INLINE;
 491                         DXDsize(&ea_buf->new_ea, min_size);
 492                         return 0;
 493                 }
 494                 current_blocks = 0;
 495         } else if (ji->ea.flag & DXD_INLINE) {
 496                 if (min_size <= sizeof (ji->i_inline_ea)) {
 497                         ea_buf->flag = EA_INLINE;
 498                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 499                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 500                         goto size_check;
 501                 }
 502                 current_blocks = 0;
 503         } else {
 504                 if (!(ji->ea.flag & DXD_EXTENT)) {
 505                         jfs_error(sb, "ea_get: invalid ea.flag)");
 506                         return -EIO;
 507                 }
 508                 current_blocks = (ea_size + sb->s_blocksize - 1) >>
 509                     sb->s_blocksize_bits;
 510         }
 511         size = max(min_size, ea_size);
 512
 513         if (size > PSIZE) {
 514                 /*
 515                  * To keep the rest of the code simple.  Allocate a
 516                  * contiguous buffer to work with
 517                  */
 518                 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
 519                 if (ea_buf->xattr == NULL)
 520                         return -ENOMEM;
 521
 522                 ea_buf->flag = EA_MALLOC;
 523                 ea_buf->max_size = (size + sb->s_blocksize - 1) &
 524                     ~(sb->s_blocksize - 1);
 525
 526                 if (ea_size == 0)
 527                         return 0;
 528
 529                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 530                         kfree(ea_buf->xattr);
 531                         ea_buf->xattr = NULL;
 532                         return rc;
 533                 }
 534                 goto size_check;
 535         }
 536         blocks_needed = (min_size + sb->s_blocksize - 1) >>
 537             sb->s_blocksize_bits;
 538
 539         if (blocks_needed > current_blocks) {
 540                 /* Allocate new blocks to quota. */
 541                 if (vfs_dq_alloc_block(inode, blocks_needed))
 542                         return -EDQUOT;
 543
 544                 quota_allocation = blocks_needed;
 545
 546                 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
 547                              &blkno);
 548                 if (rc)
 549                         goto clean_up;
 550
 551                 DXDlength(&ea_buf->new_ea, blocks_needed);
 552                 DXDaddress(&ea_buf->new_ea, blkno);
 553                 ea_buf->new_ea.flag = DXD_EXTENT;
 554                 DXDsize(&ea_buf->new_ea, min_size);
 555
 556                 ea_buf->flag = EA_EXTENT | EA_NEW;
 557
 558                 ea_buf->mp = get_metapage(inode, blkno,
 559                                           blocks_needed << sb->s_blocksize_bits,
 560                                           1);
 561                 if (ea_buf->mp == NULL) {
 562                         dbFree(inode, blkno, (s64) blocks_needed);
 563                         rc = -EIO;
 564                         goto clean_up;
 565                 }
 566                 ea_buf->xattr = ea_buf->mp->data;
 567                 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
 568                     ~(sb->s_blocksize - 1);
 569                 if (ea_size == 0)
 570                         return 0;
 571                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 572                         discard_metapage(ea_buf->mp);
 573                         dbFree(inode, blkno, (s64) blocks_needed);
 574                         goto clean_up;
 575                 }
 576                 goto size_check;
 577         }
 578         ea_buf->flag = EA_EXTENT;
 579         ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
 580                                    lengthDXD(&ji->ea) << sb->s_blocksize_bits,
 581                                    1);
 582         if (ea_buf->mp == NULL) {
 583                 rc = -EIO;
 584                 goto clean_up;
 585         }
 586         ea_buf->xattr = ea_buf->mp->data;
 587         ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
 588             ~(sb->s_blocksize - 1);
 589
 590       size_check:
 591         if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
 592                 printk(KERN_ERR "ea_get: invalid extended attribute\n");
 593                 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
 594                                      ea_buf->xattr, ea_size, 1);
 595                 ea_release(inode, ea_buf);
 596                 rc = -EIO;
 597                 goto clean_up;
 598         }
 599
 600         return ea_size;
 601
 602       clean_up:
 603         /* Rollback quota allocation */
 604         if (quota_allocation)
 605                 vfs_dq_free_block(inode, quota_allocation);
 606
 607         return (rc);
 608 }
 609
 610 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
 611 {
 612         if (ea_buf->flag & EA_MALLOC)
 613                 kfree(ea_buf->xattr);
 614         else if (ea_buf->flag & EA_EXTENT) {
 615                 assert(ea_buf->mp);
 616                 release_metapage(ea_buf->mp);
 617
 618                 if (ea_buf->flag & EA_NEW)
 619                         dbFree(inode, addressDXD(&ea_buf->new_ea),
 620                                lengthDXD(&ea_buf->new_ea));
 621         }
 622 }
 623
 624 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
 625                   int new_size)
 626 {
 627         struct jfs_inode_info *ji = JFS_IP(inode);
 628         unsigned long old_blocks, new_blocks;
 629         int rc = 0;
 630
 631         if (new_size == 0) {
 632                 ea_release(inode, ea_buf);
 633                 ea_buf = NULL;
 634         } else if (ea_buf->flag & EA_INLINE) {
 635                 assert(new_size <= sizeof (ji->i_inline_ea));
 636                 ji->mode2 &= ~INLINEEA;
 637                 ea_buf->new_ea.flag = DXD_INLINE;
 638                 DXDsize(&ea_buf->new_ea, new_size);
 639                 DXDaddress(&ea_buf->new_ea, 0);
 640                 DXDlength(&ea_buf->new_ea, 0);
 641         } else if (ea_buf->flag & EA_MALLOC) {
 642                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 643                 kfree(ea_buf->xattr);
 644         } else if (ea_buf->flag & EA_NEW) {
 645                 /* We have already allocated a new dxd */
 646                 flush_metapage(ea_buf->mp);
 647         } else {
 648                 /* ->xattr must point to original ea's metapage */
 649                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 650                 discard_metapage(ea_buf->mp);
 651         }
 652         if (rc)
 653                 return rc;
 654
 655         old_blocks = new_blocks = 0;
 656
 657         if (ji->ea.flag & DXD_EXTENT) {
 658                 invalidate_dxd_metapages(inode, ji->ea);
 659                 old_blocks = lengthDXD(&ji->ea);
 660         }
 661
 662         if (ea_buf) {
 663                 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
 664                 if (ea_buf->new_ea.flag & DXD_EXTENT) {
 665                         new_blocks = lengthDXD(&ea_buf->new_ea);
 666                         if (ji->ea.flag & DXD_INLINE)
 667                                 ji->mode2 |= INLINEEA;
 668                 }
 669                 ji->ea = ea_buf->new_ea;
 670         } else {
 671                 txEA(tid, inode, &ji->ea, NULL);
 672                 if (ji->ea.flag & DXD_INLINE)
 673                         ji->mode2 |= INLINEEA;
 674                 ji->ea.flag = 0;
 675                 ji->ea.size = 0;
 676         }
 677
 678         /* If old blocks exist, they must be removed from quota allocation. */
 679         if (old_blocks)
 680                 vfs_dq_free_block(inode, old_blocks);
 681
 682         inode->i_ctime = CURRENT_TIME;
 683
 684         return 0;
 685 }
 686
 687 /*
 688  * can_set_system_xattr
 689  *
 690  * This code is specific to the system.* namespace.  It contains policy
 691  * which doesn't belong in the main xattr codepath.
 692  */
 693 static int can_set_system_xattr(struct inode *inode, const char *name,
 694                                 const void *value, size_t value_len)
 695 {
 696 #ifdef CONFIG_JFS_POSIX_ACL
 697         struct posix_acl *acl;
 698         int rc;
 699
 700         if (!is_owner_or_cap(inode))
 701                 return -EPERM;
 702
 703         /*
 704          * POSIX_ACL_XATTR_ACCESS is tied to i_mode
 705          */
 706         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
 707                 acl = posix_acl_from_xattr(value, value_len);
 708                 if (IS_ERR(acl)) {
 709                         rc = PTR_ERR(acl);
 710                         printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
 711                                rc);
 712                         return rc;
 713                 }
 714                 if (acl) {
 715                         mode_t mode = inode->i_mode;
 716                         rc = posix_acl_equiv_mode(acl, &mode);
 717                         posix_acl_release(acl);
 718                         if (rc < 0) {
 719                                 printk(KERN_ERR
 720                                        "posix_acl_equiv_mode returned %d\n",
 721                                        rc);
 722                                 return rc;
 723                         }
 724                         inode->i_mode = mode;
 725                         mark_inode_dirty(inode);
 726                 }
 727                 /*
 728                  * We're changing the ACL.  Get rid of the cached one
 729                  */
 730                 acl =JFS_IP(inode)->i_acl;
 731                 if (acl != JFS_ACL_NOT_CACHED)
 732                         posix_acl_release(acl);
 733                 JFS_IP(inode)->i_acl = JFS_ACL_NOT_CACHED;
 734
 735                 return 0;
 736         } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
 737                 acl = posix_acl_from_xattr(value, value_len);
 738                 if (IS_ERR(acl)) {
 739                         rc = PTR_ERR(acl);
 740                         printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
 741                                rc);
 742                         return rc;
 743                 }
 744                 posix_acl_release(acl);
 745
 746                 /*
 747                  * We're changing the default ACL.  Get rid of the cached one
 748                  */
 749                 acl =JFS_IP(inode)->i_default_acl;
 750                 if (acl && (acl != JFS_ACL_NOT_CACHED))
 751                         posix_acl_release(acl);
 752                 JFS_IP(inode)->i_default_acl = JFS_ACL_NOT_CACHED;
 753
 754                 return 0;
 755         }
 756 #endif                  /* CONFIG_JFS_POSIX_ACL */
 757         return -EOPNOTSUPP;
 758 }
 759
 760 /*
 761  * Most of the permission checking is done by xattr_permission in the vfs.
 762  * The local file system is responsible for handling the system.* namespace.
 763  * We also need to verify that this is a namespace that we recognize.
 764  */
 765 static int can_set_xattr(struct inode *inode, const char *name,
 766                          const void *value, size_t value_len)
 767 {
 768         if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 769                 return can_set_system_xattr(inode, name, value, value_len);
 770
 771         /*
 772          * Don't allow setting an attribute in an unknown namespace.
 773          */
 774         if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
 775             strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
 776             strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
 777             strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))
 778                 return -EOPNOTSUPP;
 779
 780         return 0;
 781 }
 782
 783 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
 784                    const void *value, size_t value_len, int flags)
 785 {
 786         struct jfs_ea_list *ealist;
 787         struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
 788         struct ea_buffer ea_buf;
 789         int old_ea_size = 0;
 790         int xattr_size;
 791         int new_size;
 792         int namelen = strlen(name);
 793         char *os2name = NULL;
 794         int found = 0;
 795         int rc;
 796         int length;
 797
 798         if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 799                 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
 800                                   GFP_KERNEL);
 801                 if (!os2name)
 802                         return -ENOMEM;
 803                 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
 804                 name = os2name;
 805                 namelen -= XATTR_OS2_PREFIX_LEN;
 806         }
 807
 808         down_write(&JFS_IP(inode)->xattr_sem);
 809
 810         xattr_size = ea_get(inode, &ea_buf, 0);
 811         if (xattr_size < 0) {
 812                 rc = xattr_size;
 813                 goto out;
 814         }
 815
 816       again:
 817         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 818         new_size = sizeof (struct jfs_ea_list);
 819
 820         if (xattr_size) {
 821                 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
 822                      ea = NEXT_EA(ea)) {
 823                         if ((namelen == ea->namelen) &&
 824                             (memcmp(name, ea->name, namelen) == 0)) {
 825                                 found = 1;
 826                                 if (flags & XATTR_CREATE) {
 827                                         rc = -EEXIST;
 828                                         goto release;
 829                                 }
 830                                 old_ea = ea;
 831                                 old_ea_size = EA_SIZE(ea);
 832                                 next_ea = NEXT_EA(ea);
 833                         } else
 834                                 new_size += EA_SIZE(ea);
 835                 }
 836         }
 837
 838         if (!found) {
 839                 if (flags & XATTR_REPLACE) {
 840                         rc = -ENODATA;
 841                         goto release;
 842                 }
 843                 if (value == NULL) {
 844                         rc = 0;
 845                         goto release;
 846                 }
 847         }
 848         if (value)
 849                 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
 850
 851         if (new_size > ea_buf.max_size) {
 852                 /*
 853                  * We need to allocate more space for merged ea list.
 854                  * We should only have loop to again: once.
 855                  */
 856                 ea_release(inode, &ea_buf);
 857                 xattr_size = ea_get(inode, &ea_buf, new_size);
 858                 if (xattr_size < 0) {
 859                         rc = xattr_size;
 860                         goto out;
 861                 }
 862                 goto again;
 863         }
 864
 865         /* Remove old ea of the same name */
 866         if (found) {
 867                 /* number of bytes following target EA */
 868                 length = (char *) END_EALIST(ealist) - (char *) next_ea;
 869                 if (length > 0)
 870                         memmove(old_ea, next_ea, length);
 871                 xattr_size -= old_ea_size;
 872         }
 873
 874         /* Add new entry to the end */
 875         if (value) {
 876                 if (xattr_size == 0)
 877                         /* Completely new ea list */
 878                         xattr_size = sizeof (struct jfs_ea_list);
 879
 880                 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
 881                 ea->flag = 0;
 882                 ea->namelen = namelen;
 883                 ea->valuelen = (cpu_to_le16(value_len));
 884                 memcpy(ea->name, name, namelen);
 885                 ea->name[namelen] = 0;
 886                 if (value_len)
 887                         memcpy(&ea->name[namelen + 1], value, value_len);
 888                 xattr_size += EA_SIZE(ea);
 889         }
 890
 891         /* DEBUG - If we did this right, these number match */
 892         if (xattr_size != new_size) {
 893                 printk(KERN_ERR
 894                        "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
 895                        xattr_size, new_size);
 896
 897                 rc = -EINVAL;
 898                 goto release;
 899         }
 900
 901         /*
 902          * If we're left with an empty list, there's no ea
 903          */
 904         if (new_size == sizeof (struct jfs_ea_list))
 905                 new_size = 0;
 906
 907         ealist->size = cpu_to_le32(new_size);
 908
 909         rc = ea_put(tid, inode, &ea_buf, new_size);
 910
 911         goto out;
 912       release:
 913         ea_release(inode, &ea_buf);
 914       out:
 915         up_write(&JFS_IP(inode)->xattr_sem);
 916
 917         kfree(os2name);
 918
 919         return rc;
 920 }
 921
 922 int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 923                  size_t value_len, int flags)
 924 {
 925         struct inode *inode = dentry->d_inode;
 926         struct jfs_inode_info *ji = JFS_IP(inode);
 927         int rc;
 928         tid_t tid;
 929
 930         if ((rc = can_set_xattr(inode, name, value, value_len)))
 931                 return rc;
 932
 933         if (value == NULL) {    /* empty EA, do not remove */
 934                 value = "";
 935                 value_len = 0;
 936         }
 937
 938         tid = txBegin(inode->i_sb, 0);
 939         mutex_lock(&ji->commit_mutex);
 940         rc = __jfs_setxattr(tid, dentry->d_inode, name, value, value_len,
 941                             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
 950 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
 951                        size_t buf_size)
 952 {
 953         struct jfs_ea_list *ealist;
 954         struct jfs_ea *ea;
 955         struct ea_buffer ea_buf;
 956         int xattr_size;
 957         ssize_t size;
 958         int namelen = strlen(name);
 959         char *os2name = NULL;
 960         char *value;
 961
 962         if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 963                 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
 964                                   GFP_KERNEL);
 965                 if (!os2name)
 966                         return -ENOMEM;
 967                 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
 968                 name = os2name;
 969                 namelen -= XATTR_OS2_PREFIX_LEN;
 970         }
 971
 972         down_read(&JFS_IP(inode)->xattr_sem);
 973
 974         xattr_size = ea_get(inode, &ea_buf, 0);
 975
 976         if (xattr_size < 0) {
 977                 size = xattr_size;
 978                 goto out;
 979         }
 980
 981         if (xattr_size == 0)
 982                 goto not_found;
 983
 984         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 985
 986         /* Find the named attribute */
 987         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
 988                 if ((namelen == ea->namelen) &&
 989                     memcmp(name, ea->name, namelen) == 0) {
 990                         /* Found it */
 991                         size = le16_to_cpu(ea->valuelen);
 992                         if (!data)
 993                                 goto release;
 994                         else if (size > buf_size) {
 995                                 size = -ERANGE;
 996                                 goto release;
 997                         }
 998                         value = ((char *) &ea->name) + ea->namelen + 1;
 999                         memcpy(data, value, size);
1000                         goto release;
1001                 }
1002       not_found:
1003         size = -ENODATA;
1004       release:
1005         ea_release(inode, &ea_buf);
1006       out:
1007         up_read(&JFS_IP(inode)->xattr_sem);
1008
1009         kfree(os2name);
1010
1011         return size;
1012 }
1013
1014 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
1015                      size_t buf_size)
1016 {
1017         int err;
1018
1019         err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
1020
1021         return err;
1022 }
1023
1024 /*
1025  * No special permissions are needed to list attributes except for trusted.*
1026  */
1027 static inline int can_list(struct jfs_ea *ea)
1028 {
1029         return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
1030                             XATTR_TRUSTED_PREFIX_LEN) ||
1031                 capable(CAP_SYS_ADMIN));
1032 }
1033
1034 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
1035 {
1036         struct inode *inode = dentry->d_inode;
1037         char *buffer;
1038         ssize_t size = 0;
1039         int xattr_size;
1040         struct jfs_ea_list *ealist;
1041         struct jfs_ea *ea;
1042         struct ea_buffer ea_buf;
1043
1044         down_read(&JFS_IP(inode)->xattr_sem);
1045
1046         xattr_size = ea_get(inode, &ea_buf, 0);
1047         if (xattr_size < 0) {
1048                 size = xattr_size;
1049                 goto out;
1050         }
1051
1052         if (xattr_size == 0)
1053                 goto release;
1054
1055         ealist = (struct jfs_ea_list *) ea_buf.xattr;
1056
1057         /* compute required size of list */
1058         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1059                 if (can_list(ea))
1060                         size += name_size(ea) + 1;
1061         }
1062
1063         if (!data)
1064                 goto release;
1065
1066         if (size > buf_size) {
1067                 size = -ERANGE;
1068                 goto release;
1069         }
1070
1071         /* Copy attribute names to buffer */
1072         buffer = data;
1073         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1074                 if (can_list(ea)) {
1075                         int namelen = copy_name(buffer, ea);
1076                         buffer += namelen + 1;
1077                 }
1078         }
1079
1080       release:
1081         ea_release(inode, &ea_buf);
1082       out:
1083         up_read(&JFS_IP(inode)->xattr_sem);
1084         return size;
1085 }
1086
1087 int jfs_removexattr(struct dentry *dentry, const char *name)
1088 {
1089         struct inode *inode = dentry->d_inode;
1090         struct jfs_inode_info *ji = JFS_IP(inode);
1091         int rc;
1092         tid_t tid;
1093
1094         if ((rc = can_set_xattr(inode, name, NULL, 0)))
1095                 return rc;
1096
1097         tid = txBegin(inode->i_sb, 0);
1098         mutex_lock(&ji->commit_mutex);
1099         rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
1100         if (!rc)
1101                 rc = txCommit(tid, 1, &inode, 0);
1102         txEnd(tid);
1103         mutex_unlock(&ji->commit_mutex);
1104
1105         return rc;
1106 }
1107
1108 #ifdef CONFIG_JFS_SECURITY
1109 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir)
1110 {
1111         int rc;
1112         size_t len;
1113         void *value;
1114         char *suffix;
1115         char *name;
1116
1117         rc = security_inode_init_security(inode, dir, &suffix, &value, &len);
1118         if (rc) {
1119                 if (rc == -EOPNOTSUPP)
1120                         return 0;
1121                 return rc;
1122         }
1123         name = kmalloc(XATTR_SECURITY_PREFIX_LEN + 1 + strlen(suffix),
1124                        GFP_NOFS);
1125         if (!name) {
1126                 rc = -ENOMEM;
1127                 goto kmalloc_failed;
1128         }
1129         strcpy(name, XATTR_SECURITY_PREFIX);
1130         strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
1131
1132         rc = __jfs_setxattr(tid, inode, name, value, len, 0);
1133
1134         kfree(name);
1135 kmalloc_failed:
1136         kfree(suffix);
1137         kfree(value);
1138
1139         return rc;
1140 }
1141 #endif