linux/fs/jfs/xattr.c
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   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/slab.h>
  25#include <linux/quotaops.h>
  26#include <linux/security.h>
  27#include "jfs_incore.h"
  28#include "jfs_superblock.h"
  29#include "jfs_dmap.h"
  30#include "jfs_debug.h"
  31#include "jfs_dinode.h"
  32#include "jfs_extent.h"
  33#include "jfs_metapage.h"
  34#include "jfs_xattr.h"
  35#include "jfs_acl.h"
  36
  37/*
  38 *      jfs_xattr.c: extended attribute service
  39 *
  40 * Overall design --
  41 *
  42 * Format:
  43 *
  44 *   Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
  45 *   value) and a variable (0 or more) number of extended attribute
  46 *   entries.  Each extended attribute entry (jfs_ea) is a <name,value> double
  47 *   where <name> is constructed from a null-terminated ascii string
  48 *   (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
  49 *   (1 ... 65535 bytes).  The in-memory format is
  50 *
  51 *   0       1        2        4                4 + namelen + 1
  52 *   +-------+--------+--------+----------------+-------------------+
  53 *   | Flags | Name   | Value  | Name String \0 | Data . . . .      |
  54 *   |       | Length | Length |                |                   |
  55 *   +-------+--------+--------+----------------+-------------------+
  56 *
  57 *   A jfs_ea_list then is structured as
  58 *
  59 *   0            4                   4 + EA_SIZE(ea1)
  60 *   +------------+-------------------+--------------------+-----
  61 *   | Overall EA | First FEA Element | Second FEA Element | .....
  62 *   | List Size  |                   |                    |
  63 *   +------------+-------------------+--------------------+-----
  64 *
  65 *   On-disk:
  66 *
  67 *      FEALISTs are stored on disk using blocks allocated by dbAlloc() and
  68 *      written directly. An EA list may be in-lined in the inode if there is
  69 *      sufficient room available.
  70 */
  71
  72struct ea_buffer {
  73        int flag;               /* Indicates what storage xattr points to */
  74        int max_size;           /* largest xattr that fits in current buffer */
  75        dxd_t new_ea;           /* dxd to replace ea when modifying xattr */
  76        struct metapage *mp;    /* metapage containing ea list */
  77        struct jfs_ea_list *xattr;      /* buffer containing ea list */
  78};
  79
  80/*
  81 * ea_buffer.flag values
  82 */
  83#define EA_INLINE       0x0001
  84#define EA_EXTENT       0x0002
  85#define EA_NEW          0x0004
  86#define EA_MALLOC       0x0008
  87
  88
  89static int is_known_namespace(const char *name)
  90{
  91        if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
  92            strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
  93            strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
  94            strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
  95                return false;
  96
  97        return true;
  98}
  99
 100/*
 101 * These three routines are used to recognize on-disk extended attributes
 102 * that are in a recognized namespace.  If the attribute is not recognized,
 103 * "os2." is prepended to the name
 104 */
 105static int is_os2_xattr(struct jfs_ea *ea)
 106{
 107        return !is_known_namespace(ea->name);
 108}
 109
 110static inline int name_size(struct jfs_ea *ea)
 111{
 112        if (is_os2_xattr(ea))
 113                return ea->namelen + XATTR_OS2_PREFIX_LEN;
 114        else
 115                return ea->namelen;
 116}
 117
 118static inline int copy_name(char *buffer, struct jfs_ea *ea)
 119{
 120        int len = ea->namelen;
 121
 122        if (is_os2_xattr(ea)) {
 123                memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
 124                buffer += XATTR_OS2_PREFIX_LEN;
 125                len += XATTR_OS2_PREFIX_LEN;
 126        }
 127        memcpy(buffer, ea->name, ea->namelen);
 128        buffer[ea->namelen] = 0;
 129
 130        return len;
 131}
 132
 133/* Forward references */
 134static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
 135
 136/*
 137 * NAME: ea_write_inline
 138 *
 139 * FUNCTION: Attempt to write an EA inline if area is available
 140 *
 141 * PRE CONDITIONS:
 142 *      Already verified that the specified EA is small enough to fit inline
 143 *
 144 * PARAMETERS:
 145 *      ip      - Inode pointer
 146 *      ealist  - EA list pointer
 147 *      size    - size of ealist in bytes
 148 *      ea      - dxd_t structure to be filled in with necessary EA information
 149 *                if we successfully copy the EA inline
 150 *
 151 * NOTES:
 152 *      Checks if the inode's inline area is available.  If so, copies EA inline
 153 *      and sets <ea> fields appropriately.  Otherwise, returns failure, EA will
 154 *      have to be put into an extent.
 155 *
 156 * RETURNS: 0 for successful copy to inline area; -1 if area not available
 157 */
 158static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
 159                           int size, dxd_t * ea)
 160{
 161        struct jfs_inode_info *ji = JFS_IP(ip);
 162
 163        /*
 164         * Make sure we have an EA -- the NULL EA list is valid, but you
 165         * can't copy it!
 166         */
 167        if (ealist && size > sizeof (struct jfs_ea_list)) {
 168                assert(size <= sizeof (ji->i_inline_ea));
 169
 170                /*
 171                 * See if the space is available or if it is already being
 172                 * used for an inline EA.
 173                 */
 174                if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
 175                        return -EPERM;
 176
 177                DXDsize(ea, size);
 178                DXDlength(ea, 0);
 179                DXDaddress(ea, 0);
 180                memcpy(ji->i_inline_ea, ealist, size);
 181                ea->flag = DXD_INLINE;
 182                ji->mode2 &= ~INLINEEA;
 183        } else {
 184                ea->flag = 0;
 185                DXDsize(ea, 0);
 186                DXDlength(ea, 0);
 187                DXDaddress(ea, 0);
 188
 189                /* Free up INLINE area */
 190                if (ji->ea.flag & DXD_INLINE)
 191                        ji->mode2 |= INLINEEA;
 192        }
 193
 194        return 0;
 195}
 196
 197/*
 198 * NAME: ea_write
 199 *
 200 * FUNCTION: Write an EA for an inode
 201 *
 202 * PRE CONDITIONS: EA has been verified
 203 *
 204 * PARAMETERS:
 205 *      ip      - Inode pointer
 206 *      ealist  - EA list pointer
 207 *      size    - size of ealist in bytes
 208 *      ea      - dxd_t structure to be filled in appropriately with where the
 209 *                EA was copied
 210 *
 211 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
 212 *      extent and synchronously writes it to those blocks.
 213 *
 214 * RETURNS: 0 for success; Anything else indicates failure
 215 */
 216static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
 217                       dxd_t * ea)
 218{
 219        struct super_block *sb = ip->i_sb;
 220        struct jfs_inode_info *ji = JFS_IP(ip);
 221        struct jfs_sb_info *sbi = JFS_SBI(sb);
 222        int nblocks;
 223        s64 blkno;
 224        int rc = 0, i;
 225        char *cp;
 226        s32 nbytes, nb;
 227        s32 bytes_to_write;
 228        struct metapage *mp;
 229
 230        /*
 231         * Quick check to see if this is an in-linable EA.  Short EAs
 232         * and empty EAs are all in-linable, provided the space exists.
 233         */
 234        if (!ealist || size <= sizeof (ji->i_inline_ea)) {
 235                if (!ea_write_inline(ip, ealist, size, ea))
 236                        return 0;
 237        }
 238
 239        /* figure out how many blocks we need */
 240        nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
 241
 242        /* Allocate new blocks to quota. */
 243        rc = dquot_alloc_block(ip, nblocks);
 244        if (rc)
 245                return rc;
 246
 247        rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
 248        if (rc) {
 249                /*Rollback quota allocation. */
 250                dquot_free_block(ip, nblocks);
 251                return rc;
 252        }
 253
 254        /*
 255         * Now have nblocks worth of storage to stuff into the FEALIST.
 256         * loop over the FEALIST copying data into the buffer one page at
 257         * a time.
 258         */
 259        cp = (char *) ealist;
 260        nbytes = size;
 261        for (i = 0; i < nblocks; i += sbi->nbperpage) {
 262                /*
 263                 * Determine how many bytes for this request, and round up to
 264                 * the nearest aggregate block size
 265                 */
 266                nb = min(PSIZE, nbytes);
 267                bytes_to_write =
 268                    ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 269                    << sb->s_blocksize_bits;
 270
 271                if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
 272                        rc = -EIO;
 273                        goto failed;
 274                }
 275
 276                memcpy(mp->data, cp, nb);
 277
 278                /*
 279                 * We really need a way to propagate errors for
 280                 * forced writes like this one.  --hch
 281                 *
 282                 * (__write_metapage => release_metapage => flush_metapage)
 283                 */
 284#ifdef _JFS_FIXME
 285                if ((rc = flush_metapage(mp))) {
 286                        /*
 287                         * the write failed -- this means that the buffer
 288                         * is still assigned and the blocks are not being
 289                         * used.  this seems like the best error recovery
 290                         * we can get ...
 291                         */
 292                        goto failed;
 293                }
 294#else
 295                flush_metapage(mp);
 296#endif
 297
 298                cp += PSIZE;
 299                nbytes -= nb;
 300        }
 301
 302        ea->flag = DXD_EXTENT;
 303        DXDsize(ea, le32_to_cpu(ealist->size));
 304        DXDlength(ea, nblocks);
 305        DXDaddress(ea, blkno);
 306
 307        /* Free up INLINE area */
 308        if (ji->ea.flag & DXD_INLINE)
 309                ji->mode2 |= INLINEEA;
 310
 311        return 0;
 312
 313      failed:
 314        /* Rollback quota allocation. */
 315        dquot_free_block(ip, nblocks);
 316
 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 */
 332static 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 */
 366static 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        if (!nbytes) {
 385                jfs_error(sb, "ea_read: nbytes is 0");
 386                return -EIO;
 387        }
 388
 389        /*
 390         * Figure out how many blocks were allocated when this EA list was
 391         * originally written to disk.
 392         */
 393        nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
 394        blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
 395
 396        /*
 397         * I have found the disk blocks which were originally used to store
 398         * the FEALIST.  now i loop over each contiguous block copying the
 399         * data into the buffer.
 400         */
 401        for (i = 0; i < nblocks; i += sbi->nbperpage) {
 402                /*
 403                 * Determine how many bytes for this request, and round up to
 404                 * the nearest aggregate block size
 405                 */
 406                nb = min(PSIZE, nbytes);
 407                bytes_to_read =
 408                    ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 409                    << sb->s_blocksize_bits;
 410
 411                if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
 412                        return -EIO;
 413
 414                memcpy(cp, mp->data, nb);
 415                release_metapage(mp);
 416
 417                cp += PSIZE;
 418                nbytes -= nb;
 419        }
 420
 421        return 0;
 422}
 423
 424/*
 425 * NAME: ea_get
 426 *
 427 * FUNCTION: Returns buffer containing existing extended attributes.
 428 *           The size of the buffer will be the larger of the existing
 429 *           attributes size, or min_size.
 430 *
 431 *           The buffer, which may be inlined in the inode or in the
 432 *           page cache must be release by calling ea_release or ea_put
 433 *
 434 * PARAMETERS:
 435 *      inode   - Inode pointer
 436 *      ea_buf  - Structure to be populated with ealist and its metadata
 437 *      min_size- minimum size of buffer to be returned
 438 *
 439 * RETURNS: 0 for success; Other indicates failure
 440 */
 441static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
 442{
 443        struct jfs_inode_info *ji = JFS_IP(inode);
 444        struct super_block *sb = inode->i_sb;
 445        int size;
 446        int ea_size = sizeDXD(&ji->ea);
 447        int blocks_needed, current_blocks;
 448        s64 blkno;
 449        int rc;
 450        int quota_allocation = 0;
 451
 452        /* When fsck.jfs clears a bad ea, it doesn't clear the size */
 453        if (ji->ea.flag == 0)
 454                ea_size = 0;
 455
 456        if (ea_size == 0) {
 457                if (min_size == 0) {
 458                        ea_buf->flag = 0;
 459                        ea_buf->max_size = 0;
 460                        ea_buf->xattr = NULL;
 461                        return 0;
 462                }
 463                if ((min_size <= sizeof (ji->i_inline_ea)) &&
 464                    (ji->mode2 & INLINEEA)) {
 465                        ea_buf->flag = EA_INLINE | EA_NEW;
 466                        ea_buf->max_size = sizeof (ji->i_inline_ea);
 467                        ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 468                        DXDlength(&ea_buf->new_ea, 0);
 469                        DXDaddress(&ea_buf->new_ea, 0);
 470                        ea_buf->new_ea.flag = DXD_INLINE;
 471                        DXDsize(&ea_buf->new_ea, min_size);
 472                        return 0;
 473                }
 474                current_blocks = 0;
 475        } else if (ji->ea.flag & DXD_INLINE) {
 476                if (min_size <= sizeof (ji->i_inline_ea)) {
 477                        ea_buf->flag = EA_INLINE;
 478                        ea_buf->max_size = sizeof (ji->i_inline_ea);
 479                        ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 480                        goto size_check;
 481                }
 482                current_blocks = 0;
 483        } else {
 484                if (!(ji->ea.flag & DXD_EXTENT)) {
 485                        jfs_error(sb, "ea_get: invalid ea.flag)");
 486                        return -EIO;
 487                }
 488                current_blocks = (ea_size + sb->s_blocksize - 1) >>
 489                    sb->s_blocksize_bits;
 490        }
 491        size = max(min_size, ea_size);
 492
 493        if (size > PSIZE) {
 494                /*
 495                 * To keep the rest of the code simple.  Allocate a
 496                 * contiguous buffer to work with
 497                 */
 498                ea_buf->xattr = kmalloc(size, GFP_KERNEL);
 499                if (ea_buf->xattr == NULL)
 500                        return -ENOMEM;
 501
 502                ea_buf->flag = EA_MALLOC;
 503                ea_buf->max_size = (size + sb->s_blocksize - 1) &
 504                    ~(sb->s_blocksize - 1);
 505
 506                if (ea_size == 0)
 507                        return 0;
 508
 509                if ((rc = ea_read(inode, ea_buf->xattr))) {
 510                        kfree(ea_buf->xattr);
 511                        ea_buf->xattr = NULL;
 512                        return rc;
 513                }
 514                goto size_check;
 515        }
 516        blocks_needed = (min_size + sb->s_blocksize - 1) >>
 517            sb->s_blocksize_bits;
 518
 519        if (blocks_needed > current_blocks) {
 520                /* Allocate new blocks to quota. */
 521                rc = dquot_alloc_block(inode, blocks_needed);
 522                if (rc)
 523                        return -EDQUOT;
 524
 525                quota_allocation = blocks_needed;
 526
 527                rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
 528                             &blkno);
 529                if (rc)
 530                        goto clean_up;
 531
 532                DXDlength(&ea_buf->new_ea, blocks_needed);
 533                DXDaddress(&ea_buf->new_ea, blkno);
 534                ea_buf->new_ea.flag = DXD_EXTENT;
 535                DXDsize(&ea_buf->new_ea, min_size);
 536
 537                ea_buf->flag = EA_EXTENT | EA_NEW;
 538
 539                ea_buf->mp = get_metapage(inode, blkno,
 540                                          blocks_needed << sb->s_blocksize_bits,
 541                                          1);
 542                if (ea_buf->mp == NULL) {
 543                        dbFree(inode, blkno, (s64) blocks_needed);
 544                        rc = -EIO;
 545                        goto clean_up;
 546                }
 547                ea_buf->xattr = ea_buf->mp->data;
 548                ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
 549                    ~(sb->s_blocksize - 1);
 550                if (ea_size == 0)
 551                        return 0;
 552                if ((rc = ea_read(inode, ea_buf->xattr))) {
 553                        discard_metapage(ea_buf->mp);
 554                        dbFree(inode, blkno, (s64) blocks_needed);
 555                        goto clean_up;
 556                }
 557                goto size_check;
 558        }
 559        ea_buf->flag = EA_EXTENT;
 560        ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
 561                                   lengthDXD(&ji->ea) << sb->s_blocksize_bits,
 562                                   1);
 563        if (ea_buf->mp == NULL) {
 564                rc = -EIO;
 565                goto clean_up;
 566        }
 567        ea_buf->xattr = ea_buf->mp->data;
 568        ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
 569            ~(sb->s_blocksize - 1);
 570
 571      size_check:
 572        if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
 573                printk(KERN_ERR "ea_get: invalid extended attribute\n");
 574                print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
 575                                     ea_buf->xattr, ea_size, 1);
 576                ea_release(inode, ea_buf);
 577                rc = -EIO;
 578                goto clean_up;
 579        }
 580
 581        return ea_size;
 582
 583      clean_up:
 584        /* Rollback quota allocation */
 585        if (quota_allocation)
 586                dquot_free_block(inode, quota_allocation);
 587
 588        return (rc);
 589}
 590
 591static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
 592{
 593        if (ea_buf->flag & EA_MALLOC)
 594                kfree(ea_buf->xattr);
 595        else if (ea_buf->flag & EA_EXTENT) {
 596                assert(ea_buf->mp);
 597                release_metapage(ea_buf->mp);
 598
 599                if (ea_buf->flag & EA_NEW)
 600                        dbFree(inode, addressDXD(&ea_buf->new_ea),
 601                               lengthDXD(&ea_buf->new_ea));
 602        }
 603}
 604
 605static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
 606                  int new_size)
 607{
 608        struct jfs_inode_info *ji = JFS_IP(inode);
 609        unsigned long old_blocks, new_blocks;
 610        int rc = 0;
 611
 612        if (new_size == 0) {
 613                ea_release(inode, ea_buf);
 614                ea_buf = NULL;
 615        } else if (ea_buf->flag & EA_INLINE) {
 616                assert(new_size <= sizeof (ji->i_inline_ea));
 617                ji->mode2 &= ~INLINEEA;
 618                ea_buf->new_ea.flag = DXD_INLINE;
 619                DXDsize(&ea_buf->new_ea, new_size);
 620                DXDaddress(&ea_buf->new_ea, 0);
 621                DXDlength(&ea_buf->new_ea, 0);
 622        } else if (ea_buf->flag & EA_MALLOC) {
 623                rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 624                kfree(ea_buf->xattr);
 625        } else if (ea_buf->flag & EA_NEW) {
 626                /* We have already allocated a new dxd */
 627                flush_metapage(ea_buf->mp);
 628        } else {
 629                /* ->xattr must point to original ea's metapage */
 630                rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 631                discard_metapage(ea_buf->mp);
 632        }
 633        if (rc)
 634                return rc;
 635
 636        old_blocks = new_blocks = 0;
 637
 638        if (ji->ea.flag & DXD_EXTENT) {
 639                invalidate_dxd_metapages(inode, ji->ea);
 640                old_blocks = lengthDXD(&ji->ea);
 641        }
 642
 643        if (ea_buf) {
 644                txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
 645                if (ea_buf->new_ea.flag & DXD_EXTENT) {
 646                        new_blocks = lengthDXD(&ea_buf->new_ea);
 647                        if (ji->ea.flag & DXD_INLINE)
 648                                ji->mode2 |= INLINEEA;
 649                }
 650                ji->ea = ea_buf->new_ea;
 651        } else {
 652                txEA(tid, inode, &ji->ea, NULL);
 653                if (ji->ea.flag & DXD_INLINE)
 654                        ji->mode2 |= INLINEEA;
 655                ji->ea.flag = 0;
 656                ji->ea.size = 0;
 657        }
 658
 659        /* If old blocks exist, they must be removed from quota allocation. */
 660        if (old_blocks)
 661                dquot_free_block(inode, old_blocks);
 662
 663        inode->i_ctime = CURRENT_TIME;
 664
 665        return 0;
 666}
 667
 668/*
 669 * can_set_system_xattr
 670 *
 671 * This code is specific to the system.* namespace.  It contains policy
 672 * which doesn't belong in the main xattr codepath.
 673 */
 674static int can_set_system_xattr(struct inode *inode, const char *name,
 675                                const void *value, size_t value_len)
 676{
 677#ifdef CONFIG_JFS_POSIX_ACL
 678        struct posix_acl *acl;
 679        int rc;
 680
 681        if (!inode_owner_or_capable(inode))
 682                return -EPERM;
 683
 684        /*
 685         * POSIX_ACL_XATTR_ACCESS is tied to i_mode
 686         */
 687        if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
 688                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
 689                if (IS_ERR(acl)) {
 690                        rc = PTR_ERR(acl);
 691                        printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
 692                               rc);
 693                        return rc;
 694                }
 695                if (acl) {
 696                        rc = posix_acl_equiv_mode(acl, &inode->i_mode);
 697                        posix_acl_release(acl);
 698                        if (rc < 0) {
 699                                printk(KERN_ERR
 700                                       "posix_acl_equiv_mode returned %d\n",
 701                                       rc);
 702                                return rc;
 703                        }
 704                        mark_inode_dirty(inode);
 705                }
 706                /*
 707                 * We're changing the ACL.  Get rid of the cached one
 708                 */
 709                forget_cached_acl(inode, ACL_TYPE_ACCESS);
 710
 711                return 0;
 712        } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
 713                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
 714                if (IS_ERR(acl)) {
 715                        rc = PTR_ERR(acl);
 716                        printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
 717                               rc);
 718                        return rc;
 719                }
 720                posix_acl_release(acl);
 721
 722                /*
 723                 * We're changing the default ACL.  Get rid of the cached one
 724                 */
 725                forget_cached_acl(inode, ACL_TYPE_DEFAULT);
 726
 727                return 0;
 728        }
 729#endif                  /* CONFIG_JFS_POSIX_ACL */
 730        return -EOPNOTSUPP;
 731}
 732
 733/*
 734 * Most of the permission checking is done by xattr_permission in the vfs.
 735 * The local file system is responsible for handling the system.* namespace.
 736 * We also need to verify that this is a namespace that we recognize.
 737 */
 738static int can_set_xattr(struct inode *inode, const char *name,
 739                         const void *value, size_t value_len)
 740{
 741        if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 742                return can_set_system_xattr(inode, name, value, value_len);
 743
 744        if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
 745                /*
 746                 * This makes sure that we aren't trying to set an
 747                 * attribute in a different namespace by prefixing it
 748                 * with "os2."
 749                 */
 750                if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
 751                                return -EOPNOTSUPP;
 752                return 0;
 753        }
 754
 755        /*
 756         * Don't allow setting an attribute in an unknown namespace.
 757         */
 758        if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
 759            strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
 760            strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
 761                return -EOPNOTSUPP;
 762
 763        return 0;
 764}
 765
 766int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
 767                   const void *value, size_t value_len, int flags)
 768{
 769        struct jfs_ea_list *ealist;
 770        struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
 771        struct ea_buffer ea_buf;
 772        int old_ea_size = 0;
 773        int xattr_size;
 774        int new_size;
 775        int namelen = strlen(name);
 776        char *os2name = NULL;
 777        int found = 0;
 778        int rc;
 779        int length;
 780
 781        if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 782                os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
 783                                  GFP_KERNEL);
 784                if (!os2name)
 785                        return -ENOMEM;
 786                strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
 787                name = os2name;
 788                namelen -= XATTR_OS2_PREFIX_LEN;
 789        }
 790
 791        down_write(&JFS_IP(inode)->xattr_sem);
 792
 793        xattr_size = ea_get(inode, &ea_buf, 0);
 794        if (xattr_size < 0) {
 795                rc = xattr_size;
 796                goto out;
 797        }
 798
 799      again:
 800        ealist = (struct jfs_ea_list *) ea_buf.xattr;
 801        new_size = sizeof (struct jfs_ea_list);
 802
 803        if (xattr_size) {
 804                for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
 805                     ea = NEXT_EA(ea)) {
 806                        if ((namelen == ea->namelen) &&
 807                            (memcmp(name, ea->name, namelen) == 0)) {
 808                                found = 1;
 809                                if (flags & XATTR_CREATE) {
 810                                        rc = -EEXIST;
 811                                        goto release;
 812                                }
 813                                old_ea = ea;
 814                                old_ea_size = EA_SIZE(ea);
 815                                next_ea = NEXT_EA(ea);
 816                        } else
 817                                new_size += EA_SIZE(ea);
 818                }
 819        }
 820
 821        if (!found) {
 822                if (flags & XATTR_REPLACE) {
 823                        rc = -ENODATA;
 824                        goto release;
 825                }
 826                if (value == NULL) {
 827                        rc = 0;
 828                        goto release;
 829                }
 830        }
 831        if (value)
 832                new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
 833
 834        if (new_size > ea_buf.max_size) {
 835                /*
 836                 * We need to allocate more space for merged ea list.
 837                 * We should only have loop to again: once.
 838                 */
 839                ea_release(inode, &ea_buf);
 840                xattr_size = ea_get(inode, &ea_buf, new_size);
 841                if (xattr_size < 0) {
 842                        rc = xattr_size;
 843                        goto out;
 844                }
 845                goto again;
 846        }
 847
 848        /* Remove old ea of the same name */
 849        if (found) {
 850                /* number of bytes following target EA */
 851                length = (char *) END_EALIST(ealist) - (char *) next_ea;
 852                if (length > 0)
 853                        memmove(old_ea, next_ea, length);
 854                xattr_size -= old_ea_size;
 855        }
 856
 857        /* Add new entry to the end */
 858        if (value) {
 859                if (xattr_size == 0)
 860                        /* Completely new ea list */
 861                        xattr_size = sizeof (struct jfs_ea_list);
 862
 863                ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
 864                ea->flag = 0;
 865                ea->namelen = namelen;
 866                ea->valuelen = (cpu_to_le16(value_len));
 867                memcpy(ea->name, name, namelen);
 868                ea->name[namelen] = 0;
 869                if (value_len)
 870                        memcpy(&ea->name[namelen + 1], value, value_len);
 871                xattr_size += EA_SIZE(ea);
 872        }
 873
 874        /* DEBUG - If we did this right, these number match */
 875        if (xattr_size != new_size) {
 876                printk(KERN_ERR
 877                       "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
 878                       xattr_size, new_size);
 879
 880                rc = -EINVAL;
 881                goto release;
 882        }
 883
 884        /*
 885         * If we're left with an empty list, there's no ea
 886         */
 887        if (new_size == sizeof (struct jfs_ea_list))
 888                new_size = 0;
 889
 890        ealist->size = cpu_to_le32(new_size);
 891
 892        rc = ea_put(tid, inode, &ea_buf, new_size);
 893
 894        goto out;
 895      release:
 896        ea_release(inode, &ea_buf);
 897      out:
 898        up_write(&JFS_IP(inode)->xattr_sem);
 899
 900        kfree(os2name);
 901
 902        return rc;
 903}
 904
 905int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 906                 size_t value_len, int flags)
 907{
 908        struct inode *inode = dentry->d_inode;
 909        struct jfs_inode_info *ji = JFS_IP(inode);
 910        int rc;
 911        tid_t tid;
 912
 913        if ((rc = can_set_xattr(inode, name, value, value_len)))
 914                return rc;
 915
 916        if (value == NULL) {    /* empty EA, do not remove */
 917                value = "";
 918                value_len = 0;
 919        }
 920
 921        tid = txBegin(inode->i_sb, 0);
 922        mutex_lock(&ji->commit_mutex);
 923        rc = __jfs_setxattr(tid, dentry->d_inode, name, value, value_len,
 924                            flags);
 925        if (!rc)
 926                rc = txCommit(tid, 1, &inode, 0);
 927        txEnd(tid);
 928        mutex_unlock(&ji->commit_mutex);
 929
 930        return rc;
 931}
 932
 933ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
 934                       size_t buf_size)
 935{
 936        struct jfs_ea_list *ealist;
 937        struct jfs_ea *ea;
 938        struct ea_buffer ea_buf;
 939        int xattr_size;
 940        ssize_t size;
 941        int namelen = strlen(name);
 942        char *value;
 943
 944        down_read(&JFS_IP(inode)->xattr_sem);
 945
 946        xattr_size = ea_get(inode, &ea_buf, 0);
 947
 948        if (xattr_size < 0) {
 949                size = xattr_size;
 950                goto out;
 951        }
 952
 953        if (xattr_size == 0)
 954                goto not_found;
 955
 956        ealist = (struct jfs_ea_list *) ea_buf.xattr;
 957
 958        /* Find the named attribute */
 959        for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
 960                if ((namelen == ea->namelen) &&
 961                    memcmp(name, ea->name, namelen) == 0) {
 962                        /* Found it */
 963                        size = le16_to_cpu(ea->valuelen);
 964                        if (!data)
 965                                goto release;
 966                        else if (size > buf_size) {
 967                                size = -ERANGE;
 968                                goto release;
 969                        }
 970                        value = ((char *) &ea->name) + ea->namelen + 1;
 971                        memcpy(data, value, size);
 972                        goto release;
 973                }
 974      not_found:
 975        size = -ENODATA;
 976      release:
 977        ea_release(inode, &ea_buf);
 978      out:
 979        up_read(&JFS_IP(inode)->xattr_sem);
 980
 981        return size;
 982}
 983
 984ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
 985                     size_t buf_size)
 986{
 987        int err;
 988
 989        if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
 990                /*
 991                 * skip past "os2." prefix
 992                 */
 993                name += XATTR_OS2_PREFIX_LEN;
 994                /*
 995                 * Don't allow retrieving properly prefixed attributes
 996                 * by prepending them with "os2."
 997                 */
 998                if (is_known_namespace(name))
 999                        return -EOPNOTSUPP;
1000        }
1001
1002        err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
1003
1004        return err;
1005}
1006
1007/*
1008 * No special permissions are needed to list attributes except for trusted.*
1009 */
1010static inline int can_list(struct jfs_ea *ea)
1011{
1012        return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
1013                            XATTR_TRUSTED_PREFIX_LEN) ||
1014                capable(CAP_SYS_ADMIN));
1015}
1016
1017ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
1018{
1019        struct inode *inode = dentry->d_inode;
1020        char *buffer;
1021        ssize_t size = 0;
1022        int xattr_size;
1023        struct jfs_ea_list *ealist;
1024        struct jfs_ea *ea;
1025        struct ea_buffer ea_buf;
1026
1027        down_read(&JFS_IP(inode)->xattr_sem);
1028
1029        xattr_size = ea_get(inode, &ea_buf, 0);
1030        if (xattr_size < 0) {
1031                size = xattr_size;
1032                goto out;
1033        }
1034
1035        if (xattr_size == 0)
1036                goto release;
1037
1038        ealist = (struct jfs_ea_list *) ea_buf.xattr;
1039
1040        /* compute required size of list */
1041        for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1042                if (can_list(ea))
1043                        size += name_size(ea) + 1;
1044        }
1045
1046        if (!data)
1047                goto release;
1048
1049        if (size > buf_size) {
1050                size = -ERANGE;
1051                goto release;
1052        }
1053
1054        /* Copy attribute names to buffer */
1055        buffer = data;
1056        for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1057                if (can_list(ea)) {
1058                        int namelen = copy_name(buffer, ea);
1059                        buffer += namelen + 1;
1060                }
1061        }
1062
1063      release:
1064        ea_release(inode, &ea_buf);
1065      out:
1066        up_read(&JFS_IP(inode)->xattr_sem);
1067        return size;
1068}
1069
1070int jfs_removexattr(struct dentry *dentry, const char *name)
1071{
1072        struct inode *inode = dentry->d_inode;
1073        struct jfs_inode_info *ji = JFS_IP(inode);
1074        int rc;
1075        tid_t tid;
1076
1077        if ((rc = can_set_xattr(inode, name, NULL, 0)))
1078                return rc;
1079
1080        tid = txBegin(inode->i_sb, 0);
1081        mutex_lock(&ji->commit_mutex);
1082        rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
1083        if (!rc)
1084                rc = txCommit(tid, 1, &inode, 0);
1085        txEnd(tid);
1086        mutex_unlock(&ji->commit_mutex);
1087
1088        return rc;
1089}
1090
1091#ifdef CONFIG_JFS_SECURITY
1092int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1093                   void *fs_info)
1094{
1095        const struct xattr *xattr;
1096        tid_t *tid = fs_info;
1097        char *name;
1098        int err = 0;
1099
1100        for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1101                name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1102                               strlen(xattr->name) + 1, GFP_NOFS);
1103                if (!name) {
1104                        err = -ENOMEM;
1105                        break;
1106                }
1107                strcpy(name, XATTR_SECURITY_PREFIX);
1108                strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1109
1110                err = __jfs_setxattr(*tid, inode, name,
1111                                     xattr->value, xattr->value_len, 0);
1112                kfree(name);
1113                if (err < 0)
1114                        break;
1115        }
1116        return err;
1117}
1118
1119int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1120                      const struct qstr *qstr)
1121{
1122        return security_inode_init_security(inode, dir, qstr,
1123                                            &jfs_initxattrs, &tid);
1124}
1125#endif
1126
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