Pileus Git - ~andy/linux/blob - fs/xfs/xfs_dir2_data.c

   1 /*
   2  * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_types.h"
  21 #include "xfs_log.h"
  22 #include "xfs_trans.h"
  23 #include "xfs_sb.h"
  24 #include "xfs_ag.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_da_btree.h"
  27 #include "xfs_bmap_btree.h"
  28 #include "xfs_dinode.h"
  29 #include "xfs_inode.h"
  30 #include "xfs_dir2_format.h"
  31 #include "xfs_dir2_priv.h"
  32 #include "xfs_error.h"
  33
  34 STATIC xfs_dir2_data_free_t *
  35 xfs_dir2_data_freefind(xfs_dir2_data_hdr_t *hdr, xfs_dir2_data_unused_t *dup);
  36
  37 /*
  38  * Check the consistency of the data block.
  39  * The input can also be a block-format directory.
  40  * Return 0 is the buffer is good, otherwise an error.
  41  */
  42 int
  43 __xfs_dir2_data_check(
  44         struct xfs_inode        *dp,            /* incore inode pointer */
  45         struct xfs_buf          *bp)            /* data block's buffer */
  46 {
  47         xfs_dir2_dataptr_t      addr;           /* addr for leaf lookup */
  48         xfs_dir2_data_free_t    *bf;            /* bestfree table */
  49         xfs_dir2_block_tail_t   *btp=NULL;      /* block tail */
  50         int                     count;          /* count of entries found */
  51         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
  52         xfs_dir2_data_entry_t   *dep;           /* data entry */
  53         xfs_dir2_data_free_t    *dfp;           /* bestfree entry */
  54         xfs_dir2_data_unused_t  *dup;           /* unused entry */
  55         char                    *endp;          /* end of useful data */
  56         int                     freeseen;       /* mask of bestfrees seen */
  57         xfs_dahash_t            hash;           /* hash of current name */
  58         int                     i;              /* leaf index */
  59         int                     lastfree;       /* last entry was unused */
  60         xfs_dir2_leaf_entry_t   *lep=NULL;      /* block leaf entries */
  61         xfs_mount_t             *mp;            /* filesystem mount point */
  62         char                    *p;             /* current data position */
  63         int                     stale;          /* count of stale leaves */
  64         struct xfs_name         name;
  65
  66         mp = bp->b_target->bt_mount;
  67         hdr = bp->b_addr;
  68         bf = hdr->bestfree;
  69         p = (char *)(hdr + 1);
  70
  71         switch (hdr->magic) {
  72         case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
  73                 btp = xfs_dir2_block_tail_p(mp, hdr);
  74                 lep = xfs_dir2_block_leaf_p(btp);
  75                 endp = (char *)lep;
  76                 break;
  77         case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
  78                 endp = (char *)hdr + mp->m_dirblksize;
  79                 break;
  80         default:
  81                 XFS_ERROR_REPORT("Bad Magic", XFS_ERRLEVEL_LOW, mp);
  82                 return EFSCORRUPTED;
  83         }
  84
  85         count = lastfree = freeseen = 0;
  86         /*
  87          * Account for zero bestfree entries.
  88          */
  89         if (!bf[0].length) {
  90                 XFS_WANT_CORRUPTED_RETURN(!bf[0].offset);
  91                 freeseen |= 1 << 0;
  92         }
  93         if (!bf[1].length) {
  94                 XFS_WANT_CORRUPTED_RETURN(!bf[1].offset);
  95                 freeseen |= 1 << 1;
  96         }
  97         if (!bf[2].length) {
  98                 XFS_WANT_CORRUPTED_RETURN(!bf[2].offset);
  99                 freeseen |= 1 << 2;
 100         }
 101
 102         XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[0].length) >=
 103                                                 be16_to_cpu(bf[1].length));
 104         XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[1].length) >=
 105                                                 be16_to_cpu(bf[2].length));
 106         /*
 107          * Loop over the data/unused entries.
 108          */
 109         while (p < endp) {
 110                 dup = (xfs_dir2_data_unused_t *)p;
 111                 /*
 112                  * If it's unused, look for the space in the bestfree table.
 113                  * If we find it, account for that, else make sure it
 114                  * doesn't need to be there.
 115                  */
 116                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 117                         XFS_WANT_CORRUPTED_RETURN(lastfree == 0);
 118                         XFS_WANT_CORRUPTED_RETURN(
 119                                 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
 120                                                (char *)dup - (char *)hdr);
 121                         dfp = xfs_dir2_data_freefind(hdr, dup);
 122                         if (dfp) {
 123                                 i = (int)(dfp - bf);
 124                                 XFS_WANT_CORRUPTED_RETURN(
 125                                         (freeseen & (1 << i)) == 0);
 126                                 freeseen |= 1 << i;
 127                         } else {
 128                                 XFS_WANT_CORRUPTED_RETURN(
 129                                         be16_to_cpu(dup->length) <=
 130                                                 be16_to_cpu(bf[2].length));
 131                         }
 132                         p += be16_to_cpu(dup->length);
 133                         lastfree = 1;
 134                         continue;
 135                 }
 136                 /*
 137                  * It's a real entry.  Validate the fields.
 138                  * If this is a block directory then make sure it's
 139                  * in the leaf section of the block.
 140                  * The linear search is crude but this is DEBUG code.
 141                  */
 142                 dep = (xfs_dir2_data_entry_t *)p;
 143                 XFS_WANT_CORRUPTED_RETURN(dep->namelen != 0);
 144                 XFS_WANT_CORRUPTED_RETURN(
 145                         !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
 146                 XFS_WANT_CORRUPTED_RETURN(
 147                         be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
 148                                                (char *)dep - (char *)hdr);
 149                 count++;
 150                 lastfree = 0;
 151                 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
 152                         addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
 153                                 (xfs_dir2_data_aoff_t)
 154                                 ((char *)dep - (char *)hdr));
 155                         name.name = dep->name;
 156                         name.len = dep->namelen;
 157                         hash = mp->m_dirnameops->hashname(&name);
 158                         for (i = 0; i < be32_to_cpu(btp->count); i++) {
 159                                 if (be32_to_cpu(lep[i].address) == addr &&
 160                                     be32_to_cpu(lep[i].hashval) == hash)
 161                                         break;
 162                         }
 163                         XFS_WANT_CORRUPTED_RETURN(i < be32_to_cpu(btp->count));
 164                 }
 165                 p += xfs_dir2_data_entsize(dep->namelen);
 166         }
 167         /*
 168          * Need to have seen all the entries and all the bestfree slots.
 169          */
 170         XFS_WANT_CORRUPTED_RETURN(freeseen == 7);
 171         if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
 172                 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
 173                         if (lep[i].address ==
 174                             cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 175                                 stale++;
 176                         if (i > 0)
 177                                 XFS_WANT_CORRUPTED_RETURN(
 178                                         be32_to_cpu(lep[i].hashval) >=
 179                                                 be32_to_cpu(lep[i - 1].hashval));
 180                 }
 181                 XFS_WANT_CORRUPTED_RETURN(count ==
 182                         be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
 183                 XFS_WANT_CORRUPTED_RETURN(stale == be32_to_cpu(btp->stale));
 184         }
 185         return 0;
 186 }
 187
 188 static void
 189 xfs_dir2_data_verify(
 190         struct xfs_buf          *bp)
 191 {
 192         struct xfs_mount        *mp = bp->b_target->bt_mount;
 193         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 194         int                     block_ok = 0;
 195
 196         block_ok = hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 197         block_ok = block_ok && __xfs_dir2_data_check(NULL, bp) == 0;
 198
 199         if (!block_ok) {
 200                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
 201                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 202         }
 203 }
 204
 205 /*
 206  * Readahead of the first block of the directory when it is opened is completely
 207  * oblivious to the format of the directory. Hence we can either get a block
 208  * format buffer or a data format buffer on readahead.
 209  */
 210 static void
 211 xfs_dir2_data_reada_verify(
 212         struct xfs_buf          *bp)
 213 {
 214         struct xfs_mount        *mp = bp->b_target->bt_mount;
 215         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 216
 217         switch (hdr->magic) {
 218         case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
 219                 bp->b_ops = &xfs_dir2_block_buf_ops;
 220                 bp->b_ops->verify_read(bp);
 221                 return;
 222         case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 223                 xfs_dir2_data_verify(bp);
 224                 return;
 225         default:
 226                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
 227                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 228                 break;
 229         }
 230 }
 231
 232 static void
 233 xfs_dir2_data_read_verify(
 234         struct xfs_buf  *bp)
 235 {
 236         xfs_dir2_data_verify(bp);
 237 }
 238
 239 static void
 240 xfs_dir2_data_write_verify(
 241         struct xfs_buf  *bp)
 242 {
 243         xfs_dir2_data_verify(bp);
 244 }
 245
 246 const struct xfs_buf_ops xfs_dir2_data_buf_ops = {
 247         .verify_read = xfs_dir2_data_read_verify,
 248         .verify_write = xfs_dir2_data_write_verify,
 249 };
 250
 251 static const struct xfs_buf_ops xfs_dir2_data_reada_buf_ops = {
 252         .verify_read = xfs_dir2_data_reada_verify,
 253         .verify_write = xfs_dir2_data_write_verify,
 254 };
 255
 256
 257 int
 258 xfs_dir2_data_read(
 259         struct xfs_trans        *tp,
 260         struct xfs_inode        *dp,
 261         xfs_dablk_t             bno,
 262         xfs_daddr_t             mapped_bno,
 263         struct xfs_buf          **bpp)
 264 {
 265         return xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
 266                                 XFS_DATA_FORK, &xfs_dir2_data_buf_ops);
 267 }
 268
 269 int
 270 xfs_dir2_data_readahead(
 271         struct xfs_trans        *tp,
 272         struct xfs_inode        *dp,
 273         xfs_dablk_t             bno,
 274         xfs_daddr_t             mapped_bno)
 275 {
 276         return xfs_da_reada_buf(tp, dp, bno, mapped_bno,
 277                                 XFS_DATA_FORK, &xfs_dir2_data_reada_buf_ops);
 278 }
 279
 280 /*
 281  * Given a data block and an unused entry from that block,
 282  * return the bestfree entry if any that corresponds to it.
 283  */
 284 STATIC xfs_dir2_data_free_t *
 285 xfs_dir2_data_freefind(
 286         xfs_dir2_data_hdr_t     *hdr,           /* data block */
 287         xfs_dir2_data_unused_t  *dup)           /* data unused entry */
 288 {
 289         xfs_dir2_data_free_t    *dfp;           /* bestfree entry */
 290         xfs_dir2_data_aoff_t    off;            /* offset value needed */
 291 #if defined(DEBUG) && defined(__KERNEL__)
 292         int                     matched;        /* matched the value */
 293         int                     seenzero;       /* saw a 0 bestfree entry */
 294 #endif
 295
 296         off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
 297 #if defined(DEBUG) && defined(__KERNEL__)
 298         /*
 299          * Validate some consistency in the bestfree table.
 300          * Check order, non-overlapping entries, and if we find the
 301          * one we're looking for it has to be exact.
 302          */
 303         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 304                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 305         for (dfp = &hdr->bestfree[0], seenzero = matched = 0;
 306              dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
 307              dfp++) {
 308                 if (!dfp->offset) {
 309                         ASSERT(!dfp->length);
 310                         seenzero = 1;
 311                         continue;
 312                 }
 313                 ASSERT(seenzero == 0);
 314                 if (be16_to_cpu(dfp->offset) == off) {
 315                         matched = 1;
 316                         ASSERT(dfp->length == dup->length);
 317                 } else if (off < be16_to_cpu(dfp->offset))
 318                         ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
 319                 else
 320                         ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
 321                 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
 322                 if (dfp > &hdr->bestfree[0])
 323                         ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
 324         }
 325 #endif
 326         /*
 327          * If this is smaller than the smallest bestfree entry,
 328          * it can't be there since they're sorted.
 329          */
 330         if (be16_to_cpu(dup->length) <
 331             be16_to_cpu(hdr->bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
 332                 return NULL;
 333         /*
 334          * Look at the three bestfree entries for our guy.
 335          */
 336         for (dfp = &hdr->bestfree[0];
 337              dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
 338              dfp++) {
 339                 if (!dfp->offset)
 340                         return NULL;
 341                 if (be16_to_cpu(dfp->offset) == off)
 342                         return dfp;
 343         }
 344         /*
 345          * Didn't find it.  This only happens if there are duplicate lengths.
 346          */
 347         return NULL;
 348 }
 349
 350 /*
 351  * Insert an unused-space entry into the bestfree table.
 352  */
 353 xfs_dir2_data_free_t *                          /* entry inserted */
 354 xfs_dir2_data_freeinsert(
 355         xfs_dir2_data_hdr_t     *hdr,           /* data block pointer */
 356         xfs_dir2_data_unused_t  *dup,           /* unused space */
 357         int                     *loghead)       /* log the data header (out) */
 358 {
 359         xfs_dir2_data_free_t    *dfp;           /* bestfree table pointer */
 360         xfs_dir2_data_free_t    new;            /* new bestfree entry */
 361
 362 #ifdef __KERNEL__
 363         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 364                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 365 #endif
 366         dfp = hdr->bestfree;
 367         new.length = dup->length;
 368         new.offset = cpu_to_be16((char *)dup - (char *)hdr);
 369
 370         /*
 371          * Insert at position 0, 1, or 2; or not at all.
 372          */
 373         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
 374                 dfp[2] = dfp[1];
 375                 dfp[1] = dfp[0];
 376                 dfp[0] = new;
 377                 *loghead = 1;
 378                 return &dfp[0];
 379         }
 380         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
 381                 dfp[2] = dfp[1];
 382                 dfp[1] = new;
 383                 *loghead = 1;
 384                 return &dfp[1];
 385         }
 386         if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
 387                 dfp[2] = new;
 388                 *loghead = 1;
 389                 return &dfp[2];
 390         }
 391         return NULL;
 392 }
 393
 394 /*
 395  * Remove a bestfree entry from the table.
 396  */
 397 STATIC void
 398 xfs_dir2_data_freeremove(
 399         xfs_dir2_data_hdr_t     *hdr,           /* data block header */
 400         xfs_dir2_data_free_t    *dfp,           /* bestfree entry pointer */
 401         int                     *loghead)       /* out: log data header */
 402 {
 403 #ifdef __KERNEL__
 404         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 405                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 406 #endif
 407         /*
 408          * It's the first entry, slide the next 2 up.
 409          */
 410         if (dfp == &hdr->bestfree[0]) {
 411                 hdr->bestfree[0] = hdr->bestfree[1];
 412                 hdr->bestfree[1] = hdr->bestfree[2];
 413         }
 414         /*
 415          * It's the second entry, slide the 3rd entry up.
 416          */
 417         else if (dfp == &hdr->bestfree[1])
 418                 hdr->bestfree[1] = hdr->bestfree[2];
 419         /*
 420          * Must be the last entry.
 421          */
 422         else
 423                 ASSERT(dfp == &hdr->bestfree[2]);
 424         /*
 425          * Clear the 3rd entry, must be zero now.
 426          */
 427         hdr->bestfree[2].length = 0;
 428         hdr->bestfree[2].offset = 0;
 429         *loghead = 1;
 430 }
 431
 432 /*
 433  * Given a data block, reconstruct its bestfree map.
 434  */
 435 void
 436 xfs_dir2_data_freescan(
 437         xfs_mount_t             *mp,            /* filesystem mount point */
 438         xfs_dir2_data_hdr_t     *hdr,           /* data block header */
 439         int                     *loghead)       /* out: log data header */
 440 {
 441         xfs_dir2_block_tail_t   *btp;           /* block tail */
 442         xfs_dir2_data_entry_t   *dep;           /* active data entry */
 443         xfs_dir2_data_unused_t  *dup;           /* unused data entry */
 444         char                    *endp;          /* end of block's data */
 445         char                    *p;             /* current entry pointer */
 446
 447 #ifdef __KERNEL__
 448         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 449                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 450 #endif
 451         /*
 452          * Start by clearing the table.
 453          */
 454         memset(hdr->bestfree, 0, sizeof(hdr->bestfree));
 455         *loghead = 1;
 456         /*
 457          * Set up pointers.
 458          */
 459         p = (char *)(hdr + 1);
 460         if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
 461                 btp = xfs_dir2_block_tail_p(mp, hdr);
 462                 endp = (char *)xfs_dir2_block_leaf_p(btp);
 463         } else
 464                 endp = (char *)hdr + mp->m_dirblksize;
 465         /*
 466          * Loop over the block's entries.
 467          */
 468         while (p < endp) {
 469                 dup = (xfs_dir2_data_unused_t *)p;
 470                 /*
 471                  * If it's a free entry, insert it.
 472                  */
 473                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 474                         ASSERT((char *)dup - (char *)hdr ==
 475                                be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
 476                         xfs_dir2_data_freeinsert(hdr, dup, loghead);
 477                         p += be16_to_cpu(dup->length);
 478                 }
 479                 /*
 480                  * For active entries, check their tags and skip them.
 481                  */
 482                 else {
 483                         dep = (xfs_dir2_data_entry_t *)p;
 484                         ASSERT((char *)dep - (char *)hdr ==
 485                                be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
 486                         p += xfs_dir2_data_entsize(dep->namelen);
 487                 }
 488         }
 489 }
 490
 491 /*
 492  * Initialize a data block at the given block number in the directory.
 493  * Give back the buffer for the created block.
 494  */
 495 int                                             /* error */
 496 xfs_dir2_data_init(
 497         xfs_da_args_t           *args,          /* directory operation args */
 498         xfs_dir2_db_t           blkno,          /* logical dir block number */
 499         struct xfs_buf          **bpp)          /* output block buffer */
 500 {
 501         struct xfs_buf          *bp;            /* block buffer */
 502         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
 503         xfs_inode_t             *dp;            /* incore directory inode */
 504         xfs_dir2_data_unused_t  *dup;           /* unused entry pointer */
 505         int                     error;          /* error return value */
 506         int                     i;              /* bestfree index */
 507         xfs_mount_t             *mp;            /* filesystem mount point */
 508         xfs_trans_t             *tp;            /* transaction pointer */
 509         int                     t;              /* temp */
 510
 511         dp = args->dp;
 512         mp = dp->i_mount;
 513         tp = args->trans;
 514         /*
 515          * Get the buffer set up for the block.
 516          */
 517         error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
 518                 XFS_DATA_FORK);
 519         if (error)
 520                 return error;
 521         bp->b_ops = &xfs_dir2_data_buf_ops;
 522
 523         /*
 524          * Initialize the header.
 525          */
 526         hdr = bp->b_addr;
 527         hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 528         hdr->bestfree[0].offset = cpu_to_be16(sizeof(*hdr));
 529         for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
 530                 hdr->bestfree[i].length = 0;
 531                 hdr->bestfree[i].offset = 0;
 532         }
 533
 534         /*
 535          * Set up an unused entry for the block's body.
 536          */
 537         dup = (xfs_dir2_data_unused_t *)(hdr + 1);
 538         dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 539
 540         t = mp->m_dirblksize - (uint)sizeof(*hdr);
 541         hdr->bestfree[0].length = cpu_to_be16(t);
 542         dup->length = cpu_to_be16(t);
 543         *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
 544         /*
 545          * Log it and return it.
 546          */
 547         xfs_dir2_data_log_header(tp, bp);
 548         xfs_dir2_data_log_unused(tp, bp, dup);
 549         *bpp = bp;
 550         return 0;
 551 }
 552
 553 /*
 554  * Log an active data entry from the block.
 555  */
 556 void
 557 xfs_dir2_data_log_entry(
 558         struct xfs_trans        *tp,
 559         struct xfs_buf          *bp,
 560         xfs_dir2_data_entry_t   *dep)           /* data entry pointer */
 561 {
 562         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
 563
 564         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 565                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 566
 567         xfs_trans_log_buf(tp, bp, (uint)((char *)dep - (char *)hdr),
 568                 (uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
 569                        (char *)hdr - 1));
 570 }
 571
 572 /*
 573  * Log a data block header.
 574  */
 575 void
 576 xfs_dir2_data_log_header(
 577         struct xfs_trans        *tp,
 578         struct xfs_buf          *bp)
 579 {
 580         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
 581
 582         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 583                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 584
 585         xfs_trans_log_buf(tp, bp, 0, sizeof(*hdr) - 1);
 586 }
 587
 588 /*
 589  * Log a data unused entry.
 590  */
 591 void
 592 xfs_dir2_data_log_unused(
 593         struct xfs_trans        *tp,
 594         struct xfs_buf          *bp,
 595         xfs_dir2_data_unused_t  *dup)           /* data unused pointer */
 596 {
 597         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
 598
 599         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 600                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 601
 602         /*
 603          * Log the first part of the unused entry.
 604          */
 605         xfs_trans_log_buf(tp, bp, (uint)((char *)dup - (char *)hdr),
 606                 (uint)((char *)&dup->length + sizeof(dup->length) -
 607                        1 - (char *)hdr));
 608         /*
 609          * Log the end (tag) of the unused entry.
 610          */
 611         xfs_trans_log_buf(tp, bp,
 612                 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
 613                 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
 614                        sizeof(xfs_dir2_data_off_t) - 1));
 615 }
 616
 617 /*
 618  * Make a byte range in the data block unused.
 619  * Its current contents are unimportant.
 620  */
 621 void
 622 xfs_dir2_data_make_free(
 623         struct xfs_trans        *tp,
 624         struct xfs_buf          *bp,
 625         xfs_dir2_data_aoff_t    offset,         /* starting byte offset */
 626         xfs_dir2_data_aoff_t    len,            /* length in bytes */
 627         int                     *needlogp,      /* out: log header */
 628         int                     *needscanp)     /* out: regen bestfree */
 629 {
 630         xfs_dir2_data_hdr_t     *hdr;           /* data block pointer */
 631         xfs_dir2_data_free_t    *dfp;           /* bestfree pointer */
 632         char                    *endptr;        /* end of data area */
 633         xfs_mount_t             *mp;            /* filesystem mount point */
 634         int                     needscan;       /* need to regen bestfree */
 635         xfs_dir2_data_unused_t  *newdup;        /* new unused entry */
 636         xfs_dir2_data_unused_t  *postdup;       /* unused entry after us */
 637         xfs_dir2_data_unused_t  *prevdup;       /* unused entry before us */
 638
 639         mp = tp->t_mountp;
 640         hdr = bp->b_addr;
 641
 642         /*
 643          * Figure out where the end of the data area is.
 644          */
 645         if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC))
 646                 endptr = (char *)hdr + mp->m_dirblksize;
 647         else {
 648                 xfs_dir2_block_tail_t   *btp;   /* block tail */
 649
 650                 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 651                 btp = xfs_dir2_block_tail_p(mp, hdr);
 652                 endptr = (char *)xfs_dir2_block_leaf_p(btp);
 653         }
 654         /*
 655          * If this isn't the start of the block, then back up to
 656          * the previous entry and see if it's free.
 657          */
 658         if (offset > sizeof(*hdr)) {
 659                 __be16                  *tagp;  /* tag just before us */
 660
 661                 tagp = (__be16 *)((char *)hdr + offset) - 1;
 662                 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
 663                 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 664                         prevdup = NULL;
 665         } else
 666                 prevdup = NULL;
 667         /*
 668          * If this isn't the end of the block, see if the entry after
 669          * us is free.
 670          */
 671         if ((char *)hdr + offset + len < endptr) {
 672                 postdup =
 673                         (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
 674                 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 675                         postdup = NULL;
 676         } else
 677                 postdup = NULL;
 678         ASSERT(*needscanp == 0);
 679         needscan = 0;
 680         /*
 681          * Previous and following entries are both free,
 682          * merge everything into a single free entry.
 683          */
 684         if (prevdup && postdup) {
 685                 xfs_dir2_data_free_t    *dfp2;  /* another bestfree pointer */
 686
 687                 /*
 688                  * See if prevdup and/or postdup are in bestfree table.
 689                  */
 690                 dfp = xfs_dir2_data_freefind(hdr, prevdup);
 691                 dfp2 = xfs_dir2_data_freefind(hdr, postdup);
 692                 /*
 693                  * We need a rescan unless there are exactly 2 free entries
 694                  * namely our two.  Then we know what's happening, otherwise
 695                  * since the third bestfree is there, there might be more
 696                  * entries.
 697                  */
 698                 needscan = (hdr->bestfree[2].length != 0);
 699                 /*
 700                  * Fix up the new big freespace.
 701                  */
 702                 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
 703                 *xfs_dir2_data_unused_tag_p(prevdup) =
 704                         cpu_to_be16((char *)prevdup - (char *)hdr);
 705                 xfs_dir2_data_log_unused(tp, bp, prevdup);
 706                 if (!needscan) {
 707                         /*
 708                          * Has to be the case that entries 0 and 1 are
 709                          * dfp and dfp2 (don't know which is which), and
 710                          * entry 2 is empty.
 711                          * Remove entry 1 first then entry 0.
 712                          */
 713                         ASSERT(dfp && dfp2);
 714                         if (dfp == &hdr->bestfree[1]) {
 715                                 dfp = &hdr->bestfree[0];
 716                                 ASSERT(dfp2 == dfp);
 717                                 dfp2 = &hdr->bestfree[1];
 718                         }
 719                         xfs_dir2_data_freeremove(hdr, dfp2, needlogp);
 720                         xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 721                         /*
 722                          * Now insert the new entry.
 723                          */
 724                         dfp = xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
 725                         ASSERT(dfp == &hdr->bestfree[0]);
 726                         ASSERT(dfp->length == prevdup->length);
 727                         ASSERT(!dfp[1].length);
 728                         ASSERT(!dfp[2].length);
 729                 }
 730         }
 731         /*
 732          * The entry before us is free, merge with it.
 733          */
 734         else if (prevdup) {
 735                 dfp = xfs_dir2_data_freefind(hdr, prevdup);
 736                 be16_add_cpu(&prevdup->length, len);
 737                 *xfs_dir2_data_unused_tag_p(prevdup) =
 738                         cpu_to_be16((char *)prevdup - (char *)hdr);
 739                 xfs_dir2_data_log_unused(tp, bp, prevdup);
 740                 /*
 741                  * If the previous entry was in the table, the new entry
 742                  * is longer, so it will be in the table too.  Remove
 743                  * the old one and add the new one.
 744                  */
 745                 if (dfp) {
 746                         xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 747                         xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
 748                 }
 749                 /*
 750                  * Otherwise we need a scan if the new entry is big enough.
 751                  */
 752                 else {
 753                         needscan = be16_to_cpu(prevdup->length) >
 754                                    be16_to_cpu(hdr->bestfree[2].length);
 755                 }
 756         }
 757         /*
 758          * The following entry is free, merge with it.
 759          */
 760         else if (postdup) {
 761                 dfp = xfs_dir2_data_freefind(hdr, postdup);
 762                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
 763                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 764                 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
 765                 *xfs_dir2_data_unused_tag_p(newdup) =
 766                         cpu_to_be16((char *)newdup - (char *)hdr);
 767                 xfs_dir2_data_log_unused(tp, bp, newdup);
 768                 /*
 769                  * If the following entry was in the table, the new entry
 770                  * is longer, so it will be in the table too.  Remove
 771                  * the old one and add the new one.
 772                  */
 773                 if (dfp) {
 774                         xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 775                         xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
 776                 }
 777                 /*
 778                  * Otherwise we need a scan if the new entry is big enough.
 779                  */
 780                 else {
 781                         needscan = be16_to_cpu(newdup->length) >
 782                                    be16_to_cpu(hdr->bestfree[2].length);
 783                 }
 784         }
 785         /*
 786          * Neither neighbor is free.  Make a new entry.
 787          */
 788         else {
 789                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
 790                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 791                 newdup->length = cpu_to_be16(len);
 792                 *xfs_dir2_data_unused_tag_p(newdup) =
 793                         cpu_to_be16((char *)newdup - (char *)hdr);
 794                 xfs_dir2_data_log_unused(tp, bp, newdup);
 795                 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
 796         }
 797         *needscanp = needscan;
 798 }
 799
 800 /*
 801  * Take a byte range out of an existing unused space and make it un-free.
 802  */
 803 void
 804 xfs_dir2_data_use_free(
 805         struct xfs_trans        *tp,
 806         struct xfs_buf          *bp,
 807         xfs_dir2_data_unused_t  *dup,           /* unused entry */
 808         xfs_dir2_data_aoff_t    offset,         /* starting offset to use */
 809         xfs_dir2_data_aoff_t    len,            /* length to use */
 810         int                     *needlogp,      /* out: need to log header */
 811         int                     *needscanp)     /* out: need regen bestfree */
 812 {
 813         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
 814         xfs_dir2_data_free_t    *dfp;           /* bestfree pointer */
 815         int                     matchback;      /* matches end of freespace */
 816         int                     matchfront;     /* matches start of freespace */
 817         int                     needscan;       /* need to regen bestfree */
 818         xfs_dir2_data_unused_t  *newdup;        /* new unused entry */
 819         xfs_dir2_data_unused_t  *newdup2;       /* another new unused entry */
 820         int                     oldlen;         /* old unused entry's length */
 821
 822         hdr = bp->b_addr;
 823         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 824                hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
 825         ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
 826         ASSERT(offset >= (char *)dup - (char *)hdr);
 827         ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
 828         ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
 829         /*
 830          * Look up the entry in the bestfree table.
 831          */
 832         dfp = xfs_dir2_data_freefind(hdr, dup);
 833         oldlen = be16_to_cpu(dup->length);
 834         ASSERT(dfp || oldlen <= be16_to_cpu(hdr->bestfree[2].length));
 835         /*
 836          * Check for alignment with front and back of the entry.
 837          */
 838         matchfront = (char *)dup - (char *)hdr == offset;
 839         matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
 840         ASSERT(*needscanp == 0);
 841         needscan = 0;
 842         /*
 843          * If we matched it exactly we just need to get rid of it from
 844          * the bestfree table.
 845          */
 846         if (matchfront && matchback) {
 847                 if (dfp) {
 848                         needscan = (hdr->bestfree[2].offset != 0);
 849                         if (!needscan)
 850                                 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 851                 }
 852         }
 853         /*
 854          * We match the first part of the entry.
 855          * Make a new entry with the remaining freespace.
 856          */
 857         else if (matchfront) {
 858                 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
 859                 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 860                 newdup->length = cpu_to_be16(oldlen - len);
 861                 *xfs_dir2_data_unused_tag_p(newdup) =
 862                         cpu_to_be16((char *)newdup - (char *)hdr);
 863                 xfs_dir2_data_log_unused(tp, bp, newdup);
 864                 /*
 865                  * If it was in the table, remove it and add the new one.
 866                  */
 867                 if (dfp) {
 868                         xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 869                         dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
 870                         ASSERT(dfp != NULL);
 871                         ASSERT(dfp->length == newdup->length);
 872                         ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
 873                         /*
 874                          * If we got inserted at the last slot,
 875                          * that means we don't know if there was a better
 876                          * choice for the last slot, or not.  Rescan.
 877                          */
 878                         needscan = dfp == &hdr->bestfree[2];
 879                 }
 880         }
 881         /*
 882          * We match the last part of the entry.
 883          * Trim the allocated space off the tail of the entry.
 884          */
 885         else if (matchback) {
 886                 newdup = dup;
 887                 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
 888                 *xfs_dir2_data_unused_tag_p(newdup) =
 889                         cpu_to_be16((char *)newdup - (char *)hdr);
 890                 xfs_dir2_data_log_unused(tp, bp, newdup);
 891                 /*
 892                  * If it was in the table, remove it and add the new one.
 893                  */
 894                 if (dfp) {
 895                         xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 896                         dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
 897                         ASSERT(dfp != NULL);
 898                         ASSERT(dfp->length == newdup->length);
 899                         ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
 900                         /*
 901                          * If we got inserted at the last slot,
 902                          * that means we don't know if there was a better
 903                          * choice for the last slot, or not.  Rescan.
 904                          */
 905                         needscan = dfp == &hdr->bestfree[2];
 906                 }
 907         }
 908         /*
 909          * Poking out the middle of an entry.
 910          * Make two new entries.
 911          */
 912         else {
 913                 newdup = dup;
 914                 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
 915                 *xfs_dir2_data_unused_tag_p(newdup) =
 916                         cpu_to_be16((char *)newdup - (char *)hdr);
 917                 xfs_dir2_data_log_unused(tp, bp, newdup);
 918                 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
 919                 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 920                 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
 921                 *xfs_dir2_data_unused_tag_p(newdup2) =
 922                         cpu_to_be16((char *)newdup2 - (char *)hdr);
 923                 xfs_dir2_data_log_unused(tp, bp, newdup2);
 924                 /*
 925                  * If the old entry was in the table, we need to scan
 926                  * if the 3rd entry was valid, since these entries
 927                  * are smaller than the old one.
 928                  * If we don't need to scan that means there were 1 or 2
 929                  * entries in the table, and removing the old and adding
 930                  * the 2 new will work.
 931                  */
 932                 if (dfp) {
 933                         needscan = (hdr->bestfree[2].length != 0);
 934                         if (!needscan) {
 935                                 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
 936                                 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
 937                                 xfs_dir2_data_freeinsert(hdr, newdup2,
 938                                                          needlogp);
 939                         }
 940                 }
 941         }
 942         *needscanp = needscan;
 943 }