fs/xfs/xfs_attr_remote.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * Copyright (c) 2013 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * 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 the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include "xfs.h"
  20 #include "xfs_fs.h"
  21 #include "xfs_shared.h"
  22 #include "xfs_format.h"
  23 #include "xfs_log_format.h"
  24 #include "xfs_trans_resv.h"
  25 #include "xfs_bit.h"
  26 #include "xfs_sb.h"
  27 #include "xfs_ag.h"
  28 #include "xfs_mount.h"
  29 #include "xfs_da_format.h"
  30 #include "xfs_da_btree.h"
  31 #include "xfs_inode.h"
  32 #include "xfs_alloc.h"
  33 #include "xfs_trans.h"
  34 #include "xfs_inode_item.h"
  35 #include "xfs_bmap.h"
  36 #include "xfs_bmap_util.h"
  37 #include "xfs_attr.h"
  38 #include "xfs_attr_leaf.h"
  39 #include "xfs_attr_remote.h"
  40 #include "xfs_trans_space.h"
  41 #include "xfs_trace.h"
  42 #include "xfs_cksum.h"
  43 #include "xfs_buf_item.h"
  44 #include "xfs_error.h"
  45
  46 #define ATTR_RMTVALUE_MAPSIZE   1       /* # of map entries at once */
  47
  48 /*
  49  * Each contiguous block has a header, so it is not just a simple attribute
  50  * length to FSB conversion.
  51  */
  52 int
  53 xfs_attr3_rmt_blocks(
  54         struct xfs_mount *mp,
  55         int             attrlen)
  56 {
  57         if (xfs_sb_version_hascrc(&mp->m_sb)) {
  58                 int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
  59                 return (attrlen + buflen - 1) / buflen;
  60         }
  61         return XFS_B_TO_FSB(mp, attrlen);
  62 }
  63
  64 /*
  65  * Checking of the remote attribute header is split into two parts. The verifier
  66  * does CRC, location and bounds checking, the unpacking function checks the
  67  * attribute parameters and owner.
  68  */
  69 static bool
  70 xfs_attr3_rmt_hdr_ok(
  71         void                    *ptr,
  72         xfs_ino_t               ino,
  73         uint32_t                offset,
  74         uint32_t                size,
  75         xfs_daddr_t             bno)
  76 {
  77         struct xfs_attr3_rmt_hdr *rmt = ptr;
  78
  79         if (bno != be64_to_cpu(rmt->rm_blkno))
  80                 return false;
  81         if (offset != be32_to_cpu(rmt->rm_offset))
  82                 return false;
  83         if (size != be32_to_cpu(rmt->rm_bytes))
  84                 return false;
  85         if (ino != be64_to_cpu(rmt->rm_owner))
  86                 return false;
  87
  88         /* ok */
  89         return true;
  90 }
  91
  92 static bool
  93 xfs_attr3_rmt_verify(
  94         struct xfs_mount        *mp,
  95         void                    *ptr,
  96         int                     fsbsize,
  97         xfs_daddr_t             bno)
  98 {
  99         struct xfs_attr3_rmt_hdr *rmt = ptr;
 100
 101         if (!xfs_sb_version_hascrc(&mp->m_sb))
 102                 return false;
 103         if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
 104                 return false;
 105         if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_uuid))
 106                 return false;
 107         if (be64_to_cpu(rmt->rm_blkno) != bno)
 108                 return false;
 109         if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt))
 110                 return false;
 111         if (be32_to_cpu(rmt->rm_offset) +
 112                                 be32_to_cpu(rmt->rm_bytes) > XATTR_SIZE_MAX)
 113                 return false;
 114         if (rmt->rm_owner == 0)
 115                 return false;
 116
 117         return true;
 118 }
 119
 120 static void
 121 xfs_attr3_rmt_read_verify(
 122         struct xfs_buf  *bp)
 123 {
 124         struct xfs_mount *mp = bp->b_target->bt_mount;
 125         char            *ptr;
 126         int             len;
 127         xfs_daddr_t     bno;
 128         int             blksize = mp->m_attr_geo->blksize;
 129
 130         /* no verification of non-crc buffers */
 131         if (!xfs_sb_version_hascrc(&mp->m_sb))
 132                 return;
 133
 134         ptr = bp->b_addr;
 135         bno = bp->b_bn;
 136         len = BBTOB(bp->b_length);
 137         ASSERT(len >= blksize);
 138
 139         while (len > 0) {
 140                 if (!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) {
 141                         xfs_buf_ioerror(bp, EFSBADCRC);
 142                         break;
 143                 }
 144                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 145                         xfs_buf_ioerror(bp, EFSCORRUPTED);
 146                         break;
 147                 }
 148                 len -= blksize;
 149                 ptr += blksize;
 150                 bno += BTOBB(blksize);
 151         }
 152
 153         if (bp->b_error)
 154                 xfs_verifier_error(bp);
 155         else
 156                 ASSERT(len == 0);
 157 }
 158
 159 static void
 160 xfs_attr3_rmt_write_verify(
 161         struct xfs_buf  *bp)
 162 {
 163         struct xfs_mount *mp = bp->b_target->bt_mount;
 164         struct xfs_buf_log_item *bip = bp->b_fspriv;
 165         char            *ptr;
 166         int             len;
 167         xfs_daddr_t     bno;
 168         int             blksize = mp->m_attr_geo->blksize;
 169
 170         /* no verification of non-crc buffers */
 171         if (!xfs_sb_version_hascrc(&mp->m_sb))
 172                 return;
 173
 174         ptr = bp->b_addr;
 175         bno = bp->b_bn;
 176         len = BBTOB(bp->b_length);
 177         ASSERT(len >= blksize);
 178
 179         while (len > 0) {
 180                 if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
 181                         xfs_buf_ioerror(bp, EFSCORRUPTED);
 182                         xfs_verifier_error(bp);
 183                         return;
 184                 }
 185                 if (bip) {
 186                         struct xfs_attr3_rmt_hdr *rmt;
 187
 188                         rmt = (struct xfs_attr3_rmt_hdr *)ptr;
 189                         rmt->rm_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 190                 }
 191                 xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF);
 192
 193                 len -= blksize;
 194                 ptr += blksize;
 195                 bno += BTOBB(blksize);
 196         }
 197         ASSERT(len == 0);
 198 }
 199
 200 const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
 201         .verify_read = xfs_attr3_rmt_read_verify,
 202         .verify_write = xfs_attr3_rmt_write_verify,
 203 };
 204
 205 STATIC int
 206 xfs_attr3_rmt_hdr_set(
 207         struct xfs_mount        *mp,
 208         void                    *ptr,
 209         xfs_ino_t               ino,
 210         uint32_t                offset,
 211         uint32_t                size,
 212         xfs_daddr_t             bno)
 213 {
 214         struct xfs_attr3_rmt_hdr *rmt = ptr;
 215
 216         if (!xfs_sb_version_hascrc(&mp->m_sb))
 217                 return 0;
 218
 219         rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
 220         rmt->rm_offset = cpu_to_be32(offset);
 221         rmt->rm_bytes = cpu_to_be32(size);
 222         uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_uuid);
 223         rmt->rm_owner = cpu_to_be64(ino);
 224         rmt->rm_blkno = cpu_to_be64(bno);
 225
 226         return sizeof(struct xfs_attr3_rmt_hdr);
 227 }
 228
 229 /*
 230  * Helper functions to copy attribute data in and out of the one disk extents
 231  */
 232 STATIC int
 233 xfs_attr_rmtval_copyout(
 234         struct xfs_mount *mp,
 235         struct xfs_buf  *bp,
 236         xfs_ino_t       ino,
 237         int             *offset,
 238         int             *valuelen,
 239         __uint8_t       **dst)
 240 {
 241         char            *src = bp->b_addr;
 242         xfs_daddr_t     bno = bp->b_bn;
 243         int             len = BBTOB(bp->b_length);
 244         int             blksize = mp->m_attr_geo->blksize;
 245
 246         ASSERT(len >= blksize);
 247
 248         while (len > 0 && *valuelen > 0) {
 249                 int hdr_size = 0;
 250                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 251
 252                 byte_cnt = min(*valuelen, byte_cnt);
 253
 254                 if (xfs_sb_version_hascrc(&mp->m_sb)) {
 255                         if (!xfs_attr3_rmt_hdr_ok(src, ino, *offset,
 256                                                   byte_cnt, bno)) {
 257                                 xfs_alert(mp,
 258 "remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
 259                                         bno, *offset, byte_cnt, ino);
 260                                 return EFSCORRUPTED;
 261                         }
 262                         hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
 263                 }
 264
 265                 memcpy(*dst, src + hdr_size, byte_cnt);
 266
 267                 /* roll buffer forwards */
 268                 len -= blksize;
 269                 src += blksize;
 270                 bno += BTOBB(blksize);
 271
 272                 /* roll attribute data forwards */
 273                 *valuelen -= byte_cnt;
 274                 *dst += byte_cnt;
 275                 *offset += byte_cnt;
 276         }
 277         return 0;
 278 }
 279
 280 STATIC void
 281 xfs_attr_rmtval_copyin(
 282         struct xfs_mount *mp,
 283         struct xfs_buf  *bp,
 284         xfs_ino_t       ino,
 285         int             *offset,
 286         int             *valuelen,
 287         __uint8_t       **src)
 288 {
 289         char            *dst = bp->b_addr;
 290         xfs_daddr_t     bno = bp->b_bn;
 291         int             len = BBTOB(bp->b_length);
 292         int             blksize = mp->m_attr_geo->blksize;
 293
 294         ASSERT(len >= blksize);
 295
 296         while (len > 0 && *valuelen > 0) {
 297                 int hdr_size;
 298                 int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
 299
 300                 byte_cnt = min(*valuelen, byte_cnt);
 301                 hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
 302                                                  byte_cnt, bno);
 303
 304                 memcpy(dst + hdr_size, *src, byte_cnt);
 305
 306                 /*
 307                  * If this is the last block, zero the remainder of it.
 308                  * Check that we are actually the last block, too.
 309                  */
 310                 if (byte_cnt + hdr_size < blksize) {
 311                         ASSERT(*valuelen - byte_cnt == 0);
 312                         ASSERT(len == blksize);
 313                         memset(dst + hdr_size + byte_cnt, 0,
 314                                         blksize - hdr_size - byte_cnt);
 315                 }
 316
 317                 /* roll buffer forwards */
 318                 len -= blksize;
 319                 dst += blksize;
 320                 bno += BTOBB(blksize);
 321
 322                 /* roll attribute data forwards */
 323                 *valuelen -= byte_cnt;
 324                 *src += byte_cnt;
 325                 *offset += byte_cnt;
 326         }
 327 }
 328
 329 /*
 330  * Read the value associated with an attribute from the out-of-line buffer
 331  * that we stored it in.
 332  */
 333 int
 334 xfs_attr_rmtval_get(
 335         struct xfs_da_args      *args)
 336 {
 337         struct xfs_bmbt_irec    map[ATTR_RMTVALUE_MAPSIZE];
 338         struct xfs_mount        *mp = args->dp->i_mount;
 339         struct xfs_buf          *bp;
 340         xfs_dablk_t             lblkno = args->rmtblkno;
 341         __uint8_t               *dst = args->value;
 342         int                     valuelen;
 343         int                     nmap;
 344         int                     error;
 345         int                     blkcnt = args->rmtblkcnt;
 346         int                     i;
 347         int                     offset = 0;
 348
 349         trace_xfs_attr_rmtval_get(args);
 350
 351         ASSERT(!(args->flags & ATTR_KERNOVAL));
 352         ASSERT(args->rmtvaluelen == args->valuelen);
 353
 354         valuelen = args->rmtvaluelen;
 355         while (valuelen > 0) {
 356                 nmap = ATTR_RMTVALUE_MAPSIZE;
 357                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 358                                        blkcnt, map, &nmap,
 359                                        XFS_BMAPI_ATTRFORK);
 360                 if (error)
 361                         return error;
 362                 ASSERT(nmap >= 1);
 363
 364                 for (i = 0; (i < nmap) && (valuelen > 0); i++) {
 365                         xfs_daddr_t     dblkno;
 366                         int             dblkcnt;
 367
 368                         ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
 369                                (map[i].br_startblock != HOLESTARTBLOCK));
 370                         dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
 371                         dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
 372                         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 373                                                    dblkno, dblkcnt, 0, &bp,
 374                                                    &xfs_attr3_rmt_buf_ops);
 375                         if (error)
 376                                 return error;
 377
 378                         error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
 379                                                         &offset, &valuelen,
 380                                                         &dst);
 381                         xfs_buf_relse(bp);
 382                         if (error)
 383                                 return error;
 384
 385                         /* roll attribute extent map forwards */
 386                         lblkno += map[i].br_blockcount;
 387                         blkcnt -= map[i].br_blockcount;
 388                 }
 389         }
 390         ASSERT(valuelen == 0);
 391         return 0;
 392 }
 393
 394 /*
 395  * Write the value associated with an attribute into the out-of-line buffer
 396  * that we have defined for it.
 397  */
 398 int
 399 xfs_attr_rmtval_set(
 400         struct xfs_da_args      *args)
 401 {
 402         struct xfs_inode        *dp = args->dp;
 403         struct xfs_mount        *mp = dp->i_mount;
 404         struct xfs_bmbt_irec    map;
 405         xfs_dablk_t             lblkno;
 406         xfs_fileoff_t           lfileoff = 0;
 407         __uint8_t               *src = args->value;
 408         int                     blkcnt;
 409         int                     valuelen;
 410         int                     nmap;
 411         int                     error;
 412         int                     offset = 0;
 413
 414         trace_xfs_attr_rmtval_set(args);
 415
 416         /*
 417          * Find a "hole" in the attribute address space large enough for
 418          * us to drop the new attribute's value into. Because CRC enable
 419          * attributes have headers, we can't just do a straight byte to FSB
 420          * conversion and have to take the header space into account.
 421          */
 422         blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
 423         error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
 424                                                    XFS_ATTR_FORK);
 425         if (error)
 426                 return error;
 427
 428         args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
 429         args->rmtblkcnt = blkcnt;
 430
 431         /*
 432          * Roll through the "value", allocating blocks on disk as required.
 433          */
 434         while (blkcnt > 0) {
 435                 int     committed;
 436
 437                 /*
 438                  * Allocate a single extent, up to the size of the value.
 439                  */
 440                 xfs_bmap_init(args->flist, args->firstblock);
 441                 nmap = 1;
 442                 error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
 443                                   blkcnt,
 444                                   XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
 445                                   args->firstblock, args->total, &map, &nmap,
 446                                   args->flist);
 447                 if (!error) {
 448                         error = xfs_bmap_finish(&args->trans, args->flist,
 449                                                 &committed);
 450                 }
 451                 if (error) {
 452                         ASSERT(committed);
 453                         args->trans = NULL;
 454                         xfs_bmap_cancel(args->flist);
 455                         return(error);
 456                 }
 457
 458                 /*
 459                  * bmap_finish() may have committed the last trans and started
 460                  * a new one.  We need the inode to be in all transactions.
 461                  */
 462                 if (committed)
 463                         xfs_trans_ijoin(args->trans, dp, 0);
 464
 465                 ASSERT(nmap == 1);
 466                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 467                        (map.br_startblock != HOLESTARTBLOCK));
 468                 lblkno += map.br_blockcount;
 469                 blkcnt -= map.br_blockcount;
 470
 471                 /*
 472                  * Start the next trans in the chain.
 473                  */
 474                 error = xfs_trans_roll(&args->trans, dp);
 475                 if (error)
 476                         return (error);
 477         }
 478
 479         /*
 480          * Roll through the "value", copying the attribute value to the
 481          * already-allocated blocks.  Blocks are written synchronously
 482          * so that we can know they are all on disk before we turn off
 483          * the INCOMPLETE flag.
 484          */
 485         lblkno = args->rmtblkno;
 486         blkcnt = args->rmtblkcnt;
 487         valuelen = args->rmtvaluelen;
 488         while (valuelen > 0) {
 489                 struct xfs_buf  *bp;
 490                 xfs_daddr_t     dblkno;
 491                 int             dblkcnt;
 492
 493                 ASSERT(blkcnt > 0);
 494
 495                 xfs_bmap_init(args->flist, args->firstblock);
 496                 nmap = 1;
 497                 error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
 498                                        blkcnt, &map, &nmap,
 499                                        XFS_BMAPI_ATTRFORK);
 500                 if (error)
 501                         return(error);
 502                 ASSERT(nmap == 1);
 503                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 504                        (map.br_startblock != HOLESTARTBLOCK));
 505
 506                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 507                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 508
 509                 bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
 510                 if (!bp)
 511                         return ENOMEM;
 512                 bp->b_ops = &xfs_attr3_rmt_buf_ops;
 513
 514                 xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
 515                                        &valuelen, &src);
 516
 517                 error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
 518                 xfs_buf_relse(bp);
 519                 if (error)
 520                         return error;
 521
 522
 523                 /* roll attribute extent map forwards */
 524                 lblkno += map.br_blockcount;
 525                 blkcnt -= map.br_blockcount;
 526         }
 527         ASSERT(valuelen == 0);
 528         return 0;
 529 }
 530
 531 /*
 532  * Remove the value associated with an attribute by deleting the
 533  * out-of-line buffer that it is stored on.
 534  */
 535 int
 536 xfs_attr_rmtval_remove(
 537         struct xfs_da_args      *args)
 538 {
 539         struct xfs_mount        *mp = args->dp->i_mount;
 540         xfs_dablk_t             lblkno;
 541         int                     blkcnt;
 542         int                     error;
 543         int                     done;
 544
 545         trace_xfs_attr_rmtval_remove(args);
 546
 547         /*
 548          * Roll through the "value", invalidating the attribute value's blocks.
 549          */
 550         lblkno = args->rmtblkno;
 551         blkcnt = args->rmtblkcnt;
 552         while (blkcnt > 0) {
 553                 struct xfs_bmbt_irec    map;
 554                 struct xfs_buf          *bp;
 555                 xfs_daddr_t             dblkno;
 556                 int                     dblkcnt;
 557                 int                     nmap;
 558
 559                 /*
 560                  * Try to remember where we decided to put the value.
 561                  */
 562                 nmap = 1;
 563                 error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
 564                                        blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
 565                 if (error)
 566                         return(error);
 567                 ASSERT(nmap == 1);
 568                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 569                        (map.br_startblock != HOLESTARTBLOCK));
 570
 571                 dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
 572                 dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
 573
 574                 /*
 575                  * If the "remote" value is in the cache, remove it.
 576                  */
 577                 bp = xfs_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
 578                 if (bp) {
 579                         xfs_buf_stale(bp);
 580                         xfs_buf_relse(bp);
 581                         bp = NULL;
 582                 }
 583
 584                 lblkno += map.br_blockcount;
 585                 blkcnt -= map.br_blockcount;
 586         }
 587
 588         /*
 589          * Keep de-allocating extents until the remote-value region is gone.
 590          */
 591         lblkno = args->rmtblkno;
 592         blkcnt = args->rmtblkcnt;
 593         done = 0;
 594         while (!done) {
 595                 int committed;
 596
 597                 xfs_bmap_init(args->flist, args->firstblock);
 598                 error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
 599                                     XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
 600                                     1, args->firstblock, args->flist,
 601                                     &done);
 602                 if (!error) {
 603                         error = xfs_bmap_finish(&args->trans, args->flist,
 604                                                 &committed);
 605                 }
 606                 if (error) {
 607                         ASSERT(committed);
 608                         args->trans = NULL;
 609                         xfs_bmap_cancel(args->flist);
 610                         return error;
 611                 }
 612
 613                 /*
 614                  * bmap_finish() may have committed the last trans and started
 615                  * a new one.  We need the inode to be in all transactions.
 616                  */
 617                 if (committed)
 618                         xfs_trans_ijoin(args->trans, args->dp, 0);
 619
 620                 /*
 621                  * Close out trans and start the next one in the chain.
 622                  */
 623                 error = xfs_trans_roll(&args->trans, args->dp);
 624                 if (error)
 625                         return (error);
 626         }
 627         return(0);
 628 }