fs/jfs/xattr.c

   1 /*
   2  *   Copyright (c) International Business Machines  Corp., 2000-2002
   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/fs.h>
  21 #include <linux/xattr.h>
  22 #include "jfs_incore.h"
  23 #include "jfs_dmap.h"
  24 #include "jfs_debug.h"
  25 #include "jfs_dinode.h"
  26 #include "jfs_extent.h"
  27 #include "jfs_metapage.h"
  28 #include "jfs_xattr.h"
  29 #include "jfs_acl.h"
  30
  31 /*
  32  *      jfs_xattr.c: extended attribute service
  33  *
  34  * Overall design --
  35  *
  36  * Format:
  37  *
  38  *   Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
  39  *   value) and a variable (0 or more) number of extended attribute
  40  *   entries.  Each extended attribute entry (jfs_ea) is a <name,value> double
  41  *   where <name> is constructed from a null-terminated ascii string
  42  *   (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
  43  *   (1 ... 65535 bytes).  The in-memory format is
  44  *
  45  *   0       1        2        4                4 + namelen + 1
  46  *   +-------+--------+--------+----------------+-------------------+
  47  *   | Flags | Name   | Value  | Name String \0 | Data . . . .      |
  48  *   |       | Length | Length |                |                   |
  49  *   +-------+--------+--------+----------------+-------------------+
  50  *
  51  *   A jfs_ea_list then is structured as
  52  *
  53  *   0            4                   4 + EA_SIZE(ea1)
  54  *   +------------+-------------------+--------------------+-----
  55  *   | Overall EA | First FEA Element | Second FEA Element | .....
  56  *   | List Size  |                   |                    |
  57  *   +------------+-------------------+--------------------+-----
  58  *
  59  *   On-disk:
  60  *
  61  *     FEALISTs are stored on disk using blocks allocated by dbAlloc() and
  62  *     written directly. An EA list may be in-lined in the inode if there is
  63  *     sufficient room available.
  64  */
  65
  66 struct ea_buffer {
  67         int flag;               /* Indicates what storage xattr points to */
  68         int max_size;           /* largest xattr that fits in current buffer */
  69         dxd_t new_ea;           /* dxd to replace ea when modifying xattr */
  70         struct metapage *mp;    /* metapage containing ea list */
  71         struct jfs_ea_list *xattr;      /* buffer containing ea list */
  72 };
  73
  74 /*
  75  * ea_buffer.flag values
  76  */
  77 #define EA_INLINE       0x0001
  78 #define EA_EXTENT       0x0002
  79 #define EA_NEW          0x0004
  80 #define EA_MALLOC       0x0008
  81
  82 /* Namespaces */
  83 #define XATTR_SYSTEM_PREFIX "system."
  84 #define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)
  85
  86 #define XATTR_USER_PREFIX "user."
  87 #define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
  88
  89 #define XATTR_OS2_PREFIX "os2."
  90 #define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
  91
  92 /*
  93  * These three routines are used to recognize on-disk extended attributes
  94  * that are in a recognized namespace.  If the attribute is not recognized,
  95  * "os2." is prepended to the name
  96  */
  97 static inline int is_os2_xattr(struct jfs_ea *ea)
  98 {
  99         /*
 100          * Check for "system."
 101          */
 102         if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
 103             !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 104                 return FALSE;
 105         /*
 106          * Check for "user."
 107          */
 108         if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
 109             !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
 110                 return FALSE;
 111         /*
 112          * Add any other valid namespace prefixes here
 113          */
 114
 115         /*
 116          * We assume it's OS/2's flat namespace
 117          */
 118         return TRUE;
 119 }
 120
 121 static inline int name_size(struct jfs_ea *ea)
 122 {
 123         if (is_os2_xattr(ea))
 124                 return ea->namelen + XATTR_OS2_PREFIX_LEN;
 125         else
 126                 return ea->namelen;
 127 }
 128
 129 static inline int copy_name(char *buffer, struct jfs_ea *ea)
 130 {
 131         int len = ea->namelen;
 132
 133         if (is_os2_xattr(ea)) {
 134                 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
 135                 buffer += XATTR_OS2_PREFIX_LEN;
 136                 len += XATTR_OS2_PREFIX_LEN;
 137         }
 138         memcpy(buffer, ea->name, ea->namelen);
 139         buffer[ea->namelen] = 0;
 140
 141         return len;
 142 }
 143
 144 /* Forward references */
 145 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
 146
 147 /*
 148  * NAME: ea_write_inline
 149  *
 150  * FUNCTION: Attempt to write an EA inline if area is available
 151  *
 152  * PRE CONDITIONS:
 153  *      Already verified that the specified EA is small enough to fit inline
 154  *
 155  * PARAMETERS:
 156  *      ip      - Inode pointer
 157  *      ealist  - EA list pointer
 158  *      size    - size of ealist in bytes
 159  *      ea      - dxd_t structure to be filled in with necessary EA information
 160  *                if we successfully copy the EA inline
 161  *
 162  * NOTES:
 163  *      Checks if the inode's inline area is available.  If so, copies EA inline
 164  *      and sets <ea> fields appropriately.  Otherwise, returns failure, EA will
 165  *      have to be put into an extent.
 166  *
 167  * RETURNS: 0 for successful copy to inline area; -1 if area not available
 168  */
 169 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
 170                            int size, dxd_t * ea)
 171 {
 172         struct jfs_inode_info *ji = JFS_IP(ip);
 173
 174         /*
 175          * Make sure we have an EA -- the NULL EA list is valid, but you
 176          * can't copy it!
 177          */
 178         if (ealist && size > sizeof (struct jfs_ea_list)) {
 179                 assert(size <= sizeof (ji->i_inline_ea));
 180
 181                 /*
 182                  * See if the space is available or if it is already being
 183                  * used for an inline EA.
 184                  */
 185                 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
 186                         return -EPERM;
 187
 188                 DXDsize(ea, size);
 189                 DXDlength(ea, 0);
 190                 DXDaddress(ea, 0);
 191                 memcpy(ji->i_inline_ea, ealist, size);
 192                 ea->flag = DXD_INLINE;
 193                 ji->mode2 &= ~INLINEEA;
 194         } else {
 195                 ea->flag = 0;
 196                 DXDsize(ea, 0);
 197                 DXDlength(ea, 0);
 198                 DXDaddress(ea, 0);
 199
 200                 /* Free up INLINE area */
 201                 if (ji->ea.flag & DXD_INLINE)
 202                         ji->mode2 |= INLINEEA;
 203         }
 204
 205         return 0;
 206 }
 207
 208 /*
 209  * NAME: ea_write
 210  *
 211  * FUNCTION: Write an EA for an inode
 212  *
 213  * PRE CONDITIONS: EA has been verified
 214  *
 215  * PARAMETERS:
 216  *      ip      - Inode pointer
 217  *      ealist  - EA list pointer
 218  *      size    - size of ealist in bytes
 219  *      ea      - dxd_t structure to be filled in appropriately with where the
 220  *                EA was copied
 221  *
 222  * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
 223  *      extent and synchronously writes it to those blocks.
 224  *
 225  * RETURNS: 0 for success; Anything else indicates failure
 226  */
 227 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
 228                        dxd_t * ea)
 229 {
 230         struct super_block *sb = ip->i_sb;
 231         struct jfs_inode_info *ji = JFS_IP(ip);
 232         struct jfs_sb_info *sbi = JFS_SBI(sb);
 233         int nblocks;
 234         s64 blkno;
 235         int rc = 0, i;
 236         char *cp;
 237         s32 nbytes, nb;
 238         s32 bytes_to_write;
 239         struct metapage *mp;
 240
 241         /*
 242          * Quick check to see if this is an in-linable EA.  Short EAs
 243          * and empty EAs are all in-linable, provided the space exists.
 244          */
 245         if (!ealist || size <= sizeof (ji->i_inline_ea)) {
 246                 if (!ea_write_inline(ip, ealist, size, ea))
 247                         return 0;
 248         }
 249
 250         /* figure out how many blocks we need */
 251         nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
 252
 253         rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
 254         if (rc)
 255                 return rc;
 256
 257         /*
 258          * Now have nblocks worth of storage to stuff into the FEALIST.
 259          * loop over the FEALIST copying data into the buffer one page at
 260          * a time.
 261          */
 262         cp = (char *) ealist;
 263         nbytes = size;
 264         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 265                 /*
 266                  * Determine how many bytes for this request, and round up to
 267                  * the nearest aggregate block size
 268                  */
 269                 nb = min(PSIZE, nbytes);
 270                 bytes_to_write =
 271                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 272                     << sb->s_blocksize_bits;
 273
 274                 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
 275                         rc = -EIO;
 276                         goto failed;
 277                 }
 278
 279                 memcpy(mp->data, cp, nb);
 280
 281                 /*
 282                  * We really need a way to propagate errors for
 283                  * forced writes like this one.  --hch
 284                  *
 285                  * (__write_metapage => release_metapage => flush_metapage)
 286                  */
 287 #ifdef _JFS_FIXME
 288                 if ((rc = flush_metapage(mp))) {
 289                         /*
 290                          * the write failed -- this means that the buffer
 291                          * is still assigned and the blocks are not being
 292                          * used.  this seems like the best error recovery
 293                          * we can get ...
 294                          */
 295                         goto failed;
 296                 }
 297 #else
 298                 flush_metapage(mp);
 299 #endif
 300
 301                 cp += PSIZE;
 302                 nbytes -= nb;
 303         }
 304
 305         ea->flag = DXD_EXTENT;
 306         DXDsize(ea, le32_to_cpu(ealist->size));
 307         DXDlength(ea, nblocks);
 308         DXDaddress(ea, blkno);
 309
 310         /* Free up INLINE area */
 311         if (ji->ea.flag & DXD_INLINE)
 312                 ji->mode2 |= INLINEEA;
 313
 314         return 0;
 315
 316       failed:
 317         dbFree(ip, blkno, nblocks);
 318         return rc;
 319 }
 320
 321 /*
 322  * NAME: ea_read_inline
 323  *
 324  * FUNCTION: Read an inlined EA into user's buffer
 325  *
 326  * PARAMETERS:
 327  *      ip      - Inode pointer
 328  *      ealist  - Pointer to buffer to fill in with EA
 329  *
 330  * RETURNS: 0
 331  */
 332 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
 333 {
 334         struct jfs_inode_info *ji = JFS_IP(ip);
 335         int ea_size = sizeDXD(&ji->ea);
 336
 337         if (ea_size == 0) {
 338                 ealist->size = 0;
 339                 return 0;
 340         }
 341
 342         /* Sanity Check */
 343         if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
 344                 return -EIO;
 345         if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
 346             != ea_size)
 347                 return -EIO;
 348
 349         memcpy(ealist, ji->i_inline_ea, ea_size);
 350         return 0;
 351 }
 352
 353 /*
 354  * NAME: ea_read
 355  *
 356  * FUNCTION: copy EA data into user's buffer
 357  *
 358  * PARAMETERS:
 359  *      ip      - Inode pointer
 360  *      ealist  - Pointer to buffer to fill in with EA
 361  *
 362  * NOTES:  If EA is inline calls ea_read_inline() to copy EA.
 363  *
 364  * RETURNS: 0 for success; other indicates failure
 365  */
 366 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
 367 {
 368         struct super_block *sb = ip->i_sb;
 369         struct jfs_inode_info *ji = JFS_IP(ip);
 370         struct jfs_sb_info *sbi = JFS_SBI(sb);
 371         int nblocks;
 372         s64 blkno;
 373         char *cp = (char *) ealist;
 374         int i;
 375         int nbytes, nb;
 376         s32 bytes_to_read;
 377         struct metapage *mp;
 378
 379         /* quick check for in-line EA */
 380         if (ji->ea.flag & DXD_INLINE)
 381                 return ea_read_inline(ip, ealist);
 382
 383         nbytes = sizeDXD(&ji->ea);
 384         assert(nbytes);
 385
 386         /*
 387          * Figure out how many blocks were allocated when this EA list was
 388          * originally written to disk.
 389          */
 390         nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
 391         blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
 392
 393         /*
 394          * I have found the disk blocks which were originally used to store
 395          * the FEALIST.  now i loop over each contiguous block copying the
 396          * data into the buffer.
 397          */
 398         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 399                 /*
 400                  * Determine how many bytes for this request, and round up to
 401                  * the nearest aggregate block size
 402                  */
 403                 nb = min(PSIZE, nbytes);
 404                 bytes_to_read =
 405                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 406                     << sb->s_blocksize_bits;
 407
 408                 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
 409                         return -EIO;
 410
 411                 memcpy(cp, mp->data, nb);
 412                 release_metapage(mp);
 413
 414                 cp += PSIZE;
 415                 nbytes -= nb;
 416         }
 417
 418         return 0;
 419 }
 420
 421 /*
 422  * NAME: ea_get
 423  *
 424  * FUNCTION: Returns buffer containing existing extended attributes.
 425  *           The size of the buffer will be the larger of the existing
 426  *           attributes size, or min_size.
 427  *
 428  *           The buffer, which may be inlined in the inode or in the
 429  *           page cache must be release by calling ea_release or ea_put
 430  *
 431  * PARAMETERS:
 432  *      inode   - Inode pointer
 433  *      ea_buf  - Structure to be populated with ealist and its metadata
 434  *      min_size- minimum size of buffer to be returned
 435  *
 436  * RETURNS: 0 for success; Other indicates failure
 437  */
 438 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
 439 {
 440         struct jfs_inode_info *ji = JFS_IP(inode);
 441         struct super_block *sb = inode->i_sb;
 442         int size;
 443         int ea_size = sizeDXD(&ji->ea);
 444         int blocks_needed, current_blocks;
 445         s64 blkno;
 446         int rc;
 447
 448         /* When fsck.jfs clears a bad ea, it doesn't clear the size */
 449         if (ji->ea.flag == 0)
 450                 ea_size = 0;
 451
 452         if (ea_size == 0) {
 453                 if (min_size == 0) {
 454                         ea_buf->flag = 0;
 455                         ea_buf->max_size = 0;
 456                         ea_buf->xattr = NULL;
 457                         return 0;
 458                 }
 459                 if ((min_size <= sizeof (ji->i_inline_ea)) &&
 460                     (ji->mode2 & INLINEEA)) {
 461                         ea_buf->flag = EA_INLINE | EA_NEW;
 462                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 463                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 464                         DXDlength(&ea_buf->new_ea, 0);
 465                         DXDaddress(&ea_buf->new_ea, 0);
 466                         ea_buf->new_ea.flag = DXD_INLINE;
 467                         DXDsize(&ea_buf->new_ea, min_size);
 468                         return 0;
 469                 }
 470                 current_blocks = 0;
 471         } else if (ji->ea.flag & DXD_INLINE) {
 472                 if (min_size <= sizeof (ji->i_inline_ea)) {
 473                         ea_buf->flag = EA_INLINE;
 474                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 475                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 476                         goto size_check;
 477                 }
 478                 current_blocks = 0;
 479         } else {
 480                 assert(ji->ea.flag & DXD_EXTENT);
 481                 current_blocks = (ea_size + sb->s_blocksize - 1) >>
 482                     sb->s_blocksize_bits;
 483         }
 484         size = max(min_size, ea_size);
 485
 486         if (size > PSIZE) {
 487                 /*
 488                  * To keep the rest of the code simple.  Allocate a
 489                  * contiguous buffer to work with
 490                  */
 491                 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
 492                 if (ea_buf->xattr == NULL)
 493                         return -ENOMEM;
 494
 495                 ea_buf->flag |= EA_MALLOC;
 496                 ea_buf->max_size = (size + sb->s_blocksize - 1) &
 497                     ~(sb->s_blocksize - 1);
 498
 499                 if (ea_size == 0)
 500                         return 0;
 501
 502                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 503                         kfree(ea_buf->xattr);
 504                         ea_buf->xattr = NULL;
 505                         return rc;
 506                 }
 507                 goto size_check;
 508         }
 509         blocks_needed = (min_size + sb->s_blocksize - 1) >>
 510             sb->s_blocksize_bits;
 511
 512         if (blocks_needed > current_blocks) {
 513                 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
 514                              &blkno);
 515                 if (rc)
 516                         return rc;
 517
 518                 DXDlength(&ea_buf->new_ea, blocks_needed);
 519                 DXDaddress(&ea_buf->new_ea, blkno);
 520                 ea_buf->new_ea.flag = DXD_EXTENT;
 521                 DXDsize(&ea_buf->new_ea, min_size);
 522
 523                 ea_buf->flag = EA_EXTENT | EA_NEW;
 524
 525                 ea_buf->mp = get_metapage(inode, blkno,
 526                                           blocks_needed << sb->s_blocksize_bits,
 527                                           1);
 528                 if (ea_buf->mp == NULL) {
 529                         dbFree(inode, blkno, (s64) blocks_needed);
 530                         return -EIO;
 531                 }
 532                 ea_buf->xattr = ea_buf->mp->data;
 533                 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
 534                     ~(sb->s_blocksize - 1);
 535                 if (ea_size == 0)
 536                         return 0;
 537                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 538                         discard_metapage(ea_buf->mp);
 539                         dbFree(inode, blkno, (s64) blocks_needed);
 540                         return rc;
 541                 }
 542                 goto size_check;
 543         }
 544         ea_buf->flag = EA_EXTENT;
 545         ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
 546                                    lengthDXD(&ji->ea), 1);
 547         if (ea_buf->mp == NULL)
 548                 return -EIO;
 549         ea_buf->xattr = ea_buf->mp->data;
 550         ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
 551             ~(sb->s_blocksize - 1);
 552
 553       size_check:
 554         if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
 555                 printk(KERN_ERR "ea_get: invalid extended attribute\n");
 556                 dump_mem("xattr", ea_buf->xattr, ea_size);
 557                 ea_release(inode, ea_buf);
 558                 return -EIO;
 559         }
 560
 561         return ea_size;
 562 }
 563
 564 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
 565 {
 566         if (ea_buf->flag & EA_MALLOC)
 567                 kfree(ea_buf->xattr);
 568         else if (ea_buf->flag & EA_EXTENT) {
 569                 assert(ea_buf->mp);
 570                 release_metapage(ea_buf->mp);
 571
 572                 if (ea_buf->flag & EA_NEW)
 573                         dbFree(inode, addressDXD(&ea_buf->new_ea),
 574                                lengthDXD(&ea_buf->new_ea));
 575         }
 576 }
 577
 578 static int ea_put(struct inode *inode, struct ea_buffer *ea_buf, int new_size)
 579 {
 580         struct jfs_inode_info *ji = JFS_IP(inode);
 581         unsigned long old_blocks, new_blocks;
 582         int rc = 0;
 583         tid_t tid;
 584
 585         if (new_size == 0) {
 586                 ea_release(inode, ea_buf);
 587                 ea_buf = 0;
 588         } else if (ea_buf->flag & EA_INLINE) {
 589                 assert(new_size <= sizeof (ji->i_inline_ea));
 590                 ji->mode2 &= ~INLINEEA;
 591                 ea_buf->new_ea.flag = DXD_INLINE;
 592                 DXDsize(&ea_buf->new_ea, new_size);
 593                 DXDaddress(&ea_buf->new_ea, 0);
 594                 DXDlength(&ea_buf->new_ea, 0);
 595         } else if (ea_buf->flag & EA_MALLOC) {
 596                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 597                 kfree(ea_buf->xattr);
 598         } else if (ea_buf->flag & EA_NEW) {
 599                 /* We have already allocated a new dxd */
 600                 flush_metapage(ea_buf->mp);
 601         } else {
 602                 /* ->xattr must point to original ea's metapage */
 603                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 604                 discard_metapage(ea_buf->mp);
 605         }
 606         if (rc)
 607                 return rc;
 608
 609         tid = txBegin(inode->i_sb, 0);
 610         down(&ji->commit_sem);
 611
 612         old_blocks = new_blocks = 0;
 613
 614         if (ji->ea.flag & DXD_EXTENT) {
 615                 invalidate_dxd_metapages(inode, ji->ea);
 616                 old_blocks = lengthDXD(&ji->ea);
 617         }
 618
 619         if (ea_buf) {
 620                 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
 621                 if (ea_buf->new_ea.flag & DXD_EXTENT) {
 622                         new_blocks = lengthDXD(&ea_buf->new_ea);
 623                         if (ji->ea.flag & DXD_INLINE)
 624                                 ji->mode2 |= INLINEEA;
 625                 }
 626                 ji->ea = ea_buf->new_ea;
 627         } else {
 628                 txEA(tid, inode, &ji->ea, 0);
 629                 if (ji->ea.flag & DXD_INLINE)
 630                         ji->mode2 |= INLINEEA;
 631                 ji->ea.flag = 0;
 632                 ji->ea.size = 0;
 633         }
 634
 635         inode->i_blocks += LBLK2PBLK(inode->i_sb, new_blocks - old_blocks);
 636         rc = txCommit(tid, 1, &inode, 0);
 637         txEnd(tid);
 638         up(&ji->commit_sem);
 639
 640         return rc;
 641 }
 642
 643 /*
 644  * can_set_system_xattr
 645  *
 646  * This code is specific to the system.* namespace.  It contains policy
 647  * which doesn't belong in the main xattr codepath.
 648  */
 649 static int can_set_system_xattr(struct inode *inode, const char *name,
 650                                 const void *value, size_t value_len)
 651 {
 652 #ifdef CONFIG_JFS_POSIX_ACL
 653         struct posix_acl *acl;
 654         int rc;
 655
 656         if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 657                 return -EPERM;
 658
 659         /*
 660          * XATTR_NAME_ACL_ACCESS is tied to i_mode
 661          */
 662         if (strcmp(name, XATTR_NAME_ACL_ACCESS) == 0) {
 663                 acl = posix_acl_from_xattr(value, value_len);
 664                 if (acl < 0) {
 665                         printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
 666                                rc);
 667                         return rc;
 668                 }
 669                 if (acl > 0) {
 670                         mode_t mode = inode->i_mode;
 671                         rc = posix_acl_equiv_mode(acl, &mode);
 672                         posix_acl_release(acl);
 673                         if (rc < 0) {
 674                                 printk(KERN_ERR
 675                                        "posix_acl_equiv_mode returned %d\n",
 676                                        rc);
 677                                 return rc;
 678                         }
 679                         inode->i_mode = mode;
 680                         mark_inode_dirty(inode);
 681                         if (rc == 0)
 682                                 value = NULL;
 683                 }
 684                 /*
 685                  * We're changing the ACL.  Get rid of the cached one
 686                  */
 687                 acl =JFS_IP(inode)->i_acl;
 688                 if (acl && (acl != JFS_ACL_NOT_CACHED))
 689                         posix_acl_release(acl);
 690                 JFS_IP(inode)->i_acl = JFS_ACL_NOT_CACHED;
 691         } else if (strcmp(name, XATTR_NAME_ACL_DEFAULT) == 0) {
 692                 /*
 693                  * We're changing the default ACL.  Get rid of the cached one
 694                  */
 695                 acl =JFS_IP(inode)->i_default_acl;
 696                 if (acl && (acl != JFS_ACL_NOT_CACHED))
 697                         posix_acl_release(acl);
 698                 JFS_IP(inode)->i_default_acl = JFS_ACL_NOT_CACHED;
 699         } else
 700                 /* Invalid xattr name */
 701                 return -EINVAL;
 702         return 0;
 703 #else                   /* CONFIG_JFS_POSIX_ACL */
 704         return -EOPNOTSUPP;
 705 #endif                  /* CONFIG_JFS_POSIX_ACL */
 706 }
 707
 708 static int can_set_xattr(struct inode *inode, const char *name,
 709                          const void *value, size_t value_len)
 710 {
 711         if (IS_RDONLY(inode))
 712                 return -EROFS;
 713
 714         if (IS_IMMUTABLE(inode) || IS_APPEND(inode) || S_ISLNK(inode->i_mode))
 715                 return -EPERM;
 716
 717         if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
 718                 /*
 719                  * "system.*"
 720                  */
 721                 return can_set_system_xattr(inode, name, value, value_len);
 722
 723         if((strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) != 0) &&
 724            (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) != 0))
 725                 return -EOPNOTSUPP;
 726
 727         if (!S_ISREG(inode->i_mode) &&
 728             (!S_ISDIR(inode->i_mode) || inode->i_mode &S_ISVTX))
 729                 return -EPERM;
 730
 731 #ifdef CONFIG_JFS_POSIX_ACL
 732         return jfs_permission(inode, MAY_WRITE, NULL);
 733 #else
 734         return permission(inode, MAY_WRITE, NULL);
 735 #endif
 736 }
 737
 738 int __jfs_setxattr(struct inode *inode, const char *name, const void *value,
 739                    size_t value_len, int flags)
 740 {
 741         struct jfs_ea_list *ealist;
 742         struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
 743         struct ea_buffer ea_buf;
 744         int old_ea_size = 0;
 745         int xattr_size;
 746         int new_size;
 747         int namelen = strlen(name);
 748         char *os2name = NULL;
 749         int found = 0;
 750         int rc;
 751         int length;
 752
 753         if ((rc = can_set_xattr(inode, name, value, value_len)))
 754                 return rc;
 755
 756         if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 757                 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
 758                                   GFP_KERNEL);
 759                 if (!os2name)
 760                         return -ENOMEM;
 761                 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
 762                 name = os2name;
 763                 namelen -= XATTR_OS2_PREFIX_LEN;
 764         }
 765
 766         down_write(&JFS_IP(inode)->xattr_sem);
 767
 768         xattr_size = ea_get(inode, &ea_buf, 0);
 769         if (xattr_size < 0) {
 770                 rc = xattr_size;
 771                 goto out;
 772         }
 773
 774       again:
 775         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 776         new_size = sizeof (struct jfs_ea_list);
 777
 778         if (xattr_size) {
 779                 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
 780                      ea = NEXT_EA(ea)) {
 781                         if ((namelen == ea->namelen) &&
 782                             (memcmp(name, ea->name, namelen) == 0)) {
 783                                 found = 1;
 784                                 if (flags & XATTR_CREATE) {
 785                                         rc = -EEXIST;
 786                                         goto release;
 787                                 }
 788                                 old_ea = ea;
 789                                 old_ea_size = EA_SIZE(ea);
 790                                 next_ea = NEXT_EA(ea);
 791                         } else
 792                                 new_size += EA_SIZE(ea);
 793                 }
 794         }
 795
 796         if (!found) {
 797                 if (flags & XATTR_REPLACE) {
 798                         rc = -ENODATA;
 799                         goto release;
 800                 }
 801                 if (value == NULL) {
 802                         rc = 0;
 803                         goto release;
 804                 }
 805         }
 806         if (value)
 807                 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
 808
 809         if (new_size > ea_buf.max_size) {
 810                 /*
 811                  * We need to allocate more space for merged ea list.
 812                  * We should only have loop to again: once.
 813                  */
 814                 ea_release(inode, &ea_buf);
 815                 xattr_size = ea_get(inode, &ea_buf, new_size);
 816                 if (xattr_size < 0) {
 817                         rc = xattr_size;
 818                         goto out;
 819                 }
 820                 goto again;
 821         }
 822
 823         /* Remove old ea of the same name */
 824         if (found) {
 825                 /* number of bytes following target EA */
 826                 length = (char *) END_EALIST(ealist) - (char *) next_ea;
 827                 if (length > 0)
 828                         memmove(old_ea, next_ea, length);
 829                 xattr_size -= old_ea_size;
 830         }
 831
 832         /* Add new entry to the end */
 833         if (value) {
 834                 if (xattr_size == 0)
 835                         /* Completely new ea list */
 836                         xattr_size = sizeof (struct jfs_ea_list);
 837
 838                 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
 839                 ea->flag = 0;
 840                 ea->namelen = namelen;
 841                 ea->valuelen = (cpu_to_le16(value_len));
 842                 memcpy(ea->name, name, namelen);
 843                 ea->name[namelen] = 0;
 844                 if (value_len)
 845                         memcpy(&ea->name[namelen + 1], value, value_len);
 846                 xattr_size += EA_SIZE(ea);
 847         }
 848
 849         /* DEBUG - If we did this right, these number match */
 850         if (xattr_size != new_size) {
 851                 printk(KERN_ERR
 852                        "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
 853                        xattr_size, new_size);
 854
 855                 rc = -EINVAL;
 856                 goto release;
 857         }
 858
 859         /*
 860          * If we're left with an empty list, there's no ea
 861          */
 862         if (new_size == sizeof (struct jfs_ea_list))
 863                 new_size = 0;
 864
 865         ealist->size = cpu_to_le32(new_size);
 866
 867         rc = ea_put(inode, &ea_buf, new_size);
 868
 869         goto out;
 870       release:
 871         ea_release(inode, &ea_buf);
 872       out:
 873         up_write(&JFS_IP(inode)->xattr_sem);
 874
 875         if (os2name)
 876                 kfree(os2name);
 877
 878         return rc;
 879 }
 880
 881 int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 882                  size_t value_len, int flags)
 883 {
 884         if (value == NULL) {    /* empty EA, do not remove */
 885                 value = "";
 886                 value_len = 0;
 887         }
 888
 889         return __jfs_setxattr(dentry->d_inode, name, value, value_len, flags);
 890 }
 891
 892 static int can_get_xattr(struct inode *inode, const char *name)
 893 {
 894 #ifdef CONFIG_JFS_POSIX_ACL
 895         if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
 896                 return 0;
 897         return jfs_permission(inode, MAY_READ, NULL);
 898 #else
 899         return permission(inode, MAY_READ, NULL);
 900 #endif
 901 }
 902
 903 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
 904                        size_t buf_size)
 905 {
 906         struct jfs_ea_list *ealist;
 907         struct jfs_ea *ea;
 908         struct ea_buffer ea_buf;
 909         int xattr_size;
 910         ssize_t size;
 911         int namelen = strlen(name);
 912         char *os2name = NULL;
 913         int rc;
 914         char *value;
 915
 916         if ((rc = can_get_xattr(inode, name)))
 917                 return rc;
 918
 919         if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 920                 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
 921                                   GFP_KERNEL);
 922                 if (!os2name)
 923                         return -ENOMEM;
 924                 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
 925                 name = os2name;
 926                 namelen -= XATTR_OS2_PREFIX_LEN;
 927         }
 928
 929         down_read(&JFS_IP(inode)->xattr_sem);
 930
 931         xattr_size = ea_get(inode, &ea_buf, 0);
 932
 933         if (xattr_size < 0) {
 934                 size = xattr_size;
 935                 goto out;
 936         }
 937
 938         if (xattr_size == 0)
 939                 goto not_found;
 940
 941         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 942
 943         /* Find the named attribute */
 944         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
 945                 if ((namelen == ea->namelen) &&
 946                     memcmp(name, ea->name, namelen) == 0) {
 947                         /* Found it */
 948                         size = le16_to_cpu(ea->valuelen);
 949                         if (!data)
 950                                 goto release;
 951                         else if (size > buf_size) {
 952                                 size = -ERANGE;
 953                                 goto release;
 954                         }
 955                         value = ((char *) &ea->name) + ea->namelen + 1;
 956                         memcpy(data, value, size);
 957                         goto release;
 958                 }
 959       not_found:
 960         size = -ENODATA;
 961       release:
 962         ea_release(inode, &ea_buf);
 963       out:
 964         up_read(&JFS_IP(inode)->xattr_sem);
 965
 966         if (os2name)
 967                 kfree(os2name);
 968
 969         return size;
 970 }
 971
 972 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
 973                      size_t buf_size)
 974 {
 975         int err;
 976
 977         err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
 978
 979         return err;
 980 }
 981
 982 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
 983 {
 984         struct inode *inode = dentry->d_inode;
 985         char *buffer;
 986         ssize_t size = 0;
 987         int xattr_size;
 988         struct jfs_ea_list *ealist;
 989         struct jfs_ea *ea;
 990         struct ea_buffer ea_buf;
 991
 992         down_read(&JFS_IP(inode)->xattr_sem);
 993
 994         xattr_size = ea_get(inode, &ea_buf, 0);
 995         if (xattr_size < 0) {
 996                 size = xattr_size;
 997                 goto out;
 998         }
 999
1000         if (xattr_size == 0)
1001                 goto release;
1002
1003         ealist = (struct jfs_ea_list *) ea_buf.xattr;
1004
1005         /* compute required size of list */
1006         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
1007                 size += name_size(ea) + 1;
1008
1009         if (!data)
1010                 goto release;
1011
1012         if (size > buf_size) {
1013                 size = -ERANGE;
1014                 goto release;
1015         }
1016
1017         /* Copy attribute names to buffer */
1018         buffer = data;
1019         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1020                 int namelen = copy_name(buffer, ea);
1021                 buffer += namelen + 1;
1022         }
1023
1024       release:
1025         ea_release(inode, &ea_buf);
1026       out:
1027         up_read(&JFS_IP(inode)->xattr_sem);
1028         return size;
1029 }
1030
1031 int jfs_removexattr(struct dentry *dentry, const char *name)
1032 {
1033         return __jfs_setxattr(dentry->d_inode, name, 0, 0, XATTR_REPLACE);
1034 }