fs/xfs/libxfs/xfs_dir2

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This source file includes following definitions.
xfs_dir3_leafn_check
xfs_dir3_leaf_check
xfs_dir3_free_verify
xfs_dir3_free_read_verify
xfs_dir3_free_write_verify
xfs_dir3_free_header_check
__xfs_dir3_free_read
xfs_dir2_free_read
xfs_dir2_free_try_read
xfs_dir3_free_get_buf
xfs_dir2_free_log_bests
xfs_dir2_free_log_header
xfs_dir2_leaf_to_node
xfs_dir2_leafn_add
xfs_dir2_free_hdr_check
xfs_dir2_leaf_lasthash
xfs_dir2_leafn_lookup_for_addname
xfs_dir2_leafn_lookup_for_entry
xfs_dir2_leafn_lookup_int
xfs_dir3_leafn_moveents
xfs_dir2_leafn_order
xfs_dir2_leafn_rebalance
xfs_dir3_data_block_free
xfs_dir2_leafn_remove
xfs_dir2_leafn_split
xfs_dir2_leafn_toosmall
xfs_dir2_leafn_unbalance
xfs_dir2_node_add_datablk
xfs_dir2_node_find_freeblk
xfs_dir2_node_addname_int
xfs_dir2_node_addname
xfs_dir2_node_lookup
xfs_dir2_node_removename
xfs_dir2_node_replace
xfs_dir2_node_trim_free
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4  * Copyright (c) 2013 Red Hat, Inc.
   5  * All Rights Reserved.
   6  */
   7 #include "xfs.h"
   8 #include "xfs_fs.h"
   9 #include "xfs_shared.h"
  10 #include "xfs_format.h"
  11 #include "xfs_log_format.h"
  12 #include "xfs_trans_resv.h"
  13 #include "xfs_mount.h"
  14 #include "xfs_inode.h"
  15 #include "xfs_bmap.h"
  16 #include "xfs_dir2.h"
  17 #include "xfs_dir2_priv.h"
  18 #include "xfs_error.h"
  19 #include "xfs_trace.h"
  20 #include "xfs_trans.h"
  21 #include "xfs_buf_item.h"
  22 #include "xfs_log.h"
  23 
  24 /*
  25  * Function declarations.
  26  */
  27 static int xfs_dir2_leafn_add(struct xfs_buf *bp, xfs_da_args_t *args,
  28                               int index);
  29 static void xfs_dir2_leafn_rebalance(xfs_da_state_t *state,
  30                                      xfs_da_state_blk_t *blk1,
  31                                      xfs_da_state_blk_t *blk2);
  32 static int xfs_dir2_leafn_remove(xfs_da_args_t *args, struct xfs_buf *bp,
  33                                  int index, xfs_da_state_blk_t *dblk,
  34                                  int *rval);
  35 
  36 /*
  37  * Check internal consistency of a leafn block.
  38  */
  39 #ifdef DEBUG
  40 static xfs_failaddr_t
  41 xfs_dir3_leafn_check(
  42         struct xfs_inode        *dp,
  43         struct xfs_buf          *bp)
  44 {
  45         struct xfs_dir2_leaf    *leaf = bp->b_addr;
  46         struct xfs_dir3_icleaf_hdr leafhdr;
  47 
  48         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
  49 
  50         if (leafhdr.magic == XFS_DIR3_LEAFN_MAGIC) {
  51                 struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
  52                 if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
  53                         return __this_address;
  54         } else if (leafhdr.magic != XFS_DIR2_LEAFN_MAGIC)
  55                 return __this_address;
  56 
  57         return xfs_dir3_leaf_check_int(dp->i_mount, dp, &leafhdr, leaf);
  58 }
  59 
  60 static inline void
  61 xfs_dir3_leaf_check(
  62         struct xfs_inode        *dp,
  63         struct xfs_buf          *bp)
  64 {
  65         xfs_failaddr_t          fa;
  66 
  67         fa = xfs_dir3_leafn_check(dp, bp);
  68         if (!fa)
  69                 return;
  70         xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, dp->i_mount,
  71                         bp->b_addr, BBTOB(bp->b_length), __FILE__, __LINE__,
  72                         fa);
  73         ASSERT(0);
  74 }
  75 #else
  76 #define xfs_dir3_leaf_check(dp, bp)
  77 #endif
  78 
  79 static xfs_failaddr_t
  80 xfs_dir3_free_verify(
  81         struct xfs_buf          *bp)
  82 {
  83         struct xfs_mount        *mp = bp->b_mount;
  84         struct xfs_dir2_free_hdr *hdr = bp->b_addr;
  85 
  86         if (!xfs_verify_magic(bp, hdr->magic))
  87                 return __this_address;
  88 
  89         if (xfs_sb_version_hascrc(&mp->m_sb)) {
  90                 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
  91 
  92                 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
  93                         return __this_address;
  94                 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
  95                         return __this_address;
  96                 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
  97                         return __this_address;
  98         }
  99 
 100         /* XXX: should bounds check the xfs_dir3_icfree_hdr here */
 101 
 102         return NULL;
 103 }
 104 
 105 static void
 106 xfs_dir3_free_read_verify(
 107         struct xfs_buf  *bp)
 108 {
 109         struct xfs_mount        *mp = bp->b_mount;
 110         xfs_failaddr_t          fa;
 111 
 112         if (xfs_sb_version_hascrc(&mp->m_sb) &&
 113             !xfs_buf_verify_cksum(bp, XFS_DIR3_FREE_CRC_OFF))
 114                 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 115         else {
 116                 fa = xfs_dir3_free_verify(bp);
 117                 if (fa)
 118                         xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 119         }
 120 }
 121 
 122 static void
 123 xfs_dir3_free_write_verify(
 124         struct xfs_buf  *bp)
 125 {
 126         struct xfs_mount        *mp = bp->b_mount;
 127         struct xfs_buf_log_item *bip = bp->b_log_item;
 128         struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
 129         xfs_failaddr_t          fa;
 130 
 131         fa = xfs_dir3_free_verify(bp);
 132         if (fa) {
 133                 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 134                 return;
 135         }
 136 
 137         if (!xfs_sb_version_hascrc(&mp->m_sb))
 138                 return;
 139 
 140         if (bip)
 141                 hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
 142 
 143         xfs_buf_update_cksum(bp, XFS_DIR3_FREE_CRC_OFF);
 144 }
 145 
 146 const struct xfs_buf_ops xfs_dir3_free_buf_ops = {
 147         .name = "xfs_dir3_free",
 148         .magic = { cpu_to_be32(XFS_DIR2_FREE_MAGIC),
 149                    cpu_to_be32(XFS_DIR3_FREE_MAGIC) },
 150         .verify_read = xfs_dir3_free_read_verify,
 151         .verify_write = xfs_dir3_free_write_verify,
 152         .verify_struct = xfs_dir3_free_verify,
 153 };
 154 
 155 /* Everything ok in the free block header? */
 156 static xfs_failaddr_t
 157 xfs_dir3_free_header_check(
 158         struct xfs_inode        *dp,
 159         xfs_dablk_t             fbno,
 160         struct xfs_buf          *bp)
 161 {
 162         struct xfs_mount        *mp = dp->i_mount;
 163         unsigned int            firstdb;
 164         int                     maxbests;
 165 
 166         maxbests = dp->d_ops->free_max_bests(mp->m_dir_geo);
 167         firstdb = (xfs_dir2_da_to_db(mp->m_dir_geo, fbno) -
 168                    xfs_dir2_byte_to_db(mp->m_dir_geo, XFS_DIR2_FREE_OFFSET)) *
 169                         maxbests;
 170         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 171                 struct xfs_dir3_free_hdr *hdr3 = bp->b_addr;
 172 
 173                 if (be32_to_cpu(hdr3->firstdb) != firstdb)
 174                         return __this_address;
 175                 if (be32_to_cpu(hdr3->nvalid) > maxbests)
 176                         return __this_address;
 177                 if (be32_to_cpu(hdr3->nvalid) < be32_to_cpu(hdr3->nused))
 178                         return __this_address;
 179         } else {
 180                 struct xfs_dir2_free_hdr *hdr = bp->b_addr;
 181 
 182                 if (be32_to_cpu(hdr->firstdb) != firstdb)
 183                         return __this_address;
 184                 if (be32_to_cpu(hdr->nvalid) > maxbests)
 185                         return __this_address;
 186                 if (be32_to_cpu(hdr->nvalid) < be32_to_cpu(hdr->nused))
 187                         return __this_address;
 188         }
 189         return NULL;
 190 }
 191 
 192 static int
 193 __xfs_dir3_free_read(
 194         struct xfs_trans        *tp,
 195         struct xfs_inode        *dp,
 196         xfs_dablk_t             fbno,
 197         xfs_daddr_t             mappedbno,
 198         struct xfs_buf          **bpp)
 199 {
 200         xfs_failaddr_t          fa;
 201         int                     err;
 202 
 203         err = xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
 204                                 XFS_DATA_FORK, &xfs_dir3_free_buf_ops);
 205         if (err || !*bpp)
 206                 return err;
 207 
 208         /* Check things that we can't do in the verifier. */
 209         fa = xfs_dir3_free_header_check(dp, fbno, *bpp);
 210         if (fa) {
 211                 xfs_verifier_error(*bpp, -EFSCORRUPTED, fa);
 212                 xfs_trans_brelse(tp, *bpp);
 213                 return -EFSCORRUPTED;
 214         }
 215 
 216         /* try read returns without an error or *bpp if it lands in a hole */
 217         if (tp)
 218                 xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_FREE_BUF);
 219 
 220         return 0;
 221 }
 222 
 223 int
 224 xfs_dir2_free_read(
 225         struct xfs_trans        *tp,
 226         struct xfs_inode        *dp,
 227         xfs_dablk_t             fbno,
 228         struct xfs_buf          **bpp)
 229 {
 230         return __xfs_dir3_free_read(tp, dp, fbno, -1, bpp);
 231 }
 232 
 233 static int
 234 xfs_dir2_free_try_read(
 235         struct xfs_trans        *tp,
 236         struct xfs_inode        *dp,
 237         xfs_dablk_t             fbno,
 238         struct xfs_buf          **bpp)
 239 {
 240         return __xfs_dir3_free_read(tp, dp, fbno, -2, bpp);
 241 }
 242 
 243 static int
 244 xfs_dir3_free_get_buf(
 245         xfs_da_args_t           *args,
 246         xfs_dir2_db_t           fbno,
 247         struct xfs_buf          **bpp)
 248 {
 249         struct xfs_trans        *tp = args->trans;
 250         struct xfs_inode        *dp = args->dp;
 251         struct xfs_mount        *mp = dp->i_mount;
 252         struct xfs_buf          *bp;
 253         int                     error;
 254         struct xfs_dir3_icfree_hdr hdr;
 255 
 256         error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, fbno),
 257                                    -1, &bp, XFS_DATA_FORK);
 258         if (error)
 259                 return error;
 260 
 261         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_FREE_BUF);
 262         bp->b_ops = &xfs_dir3_free_buf_ops;
 263 
 264         /*
 265          * Initialize the new block to be empty, and remember
 266          * its first slot as our empty slot.
 267          */
 268         memset(bp->b_addr, 0, sizeof(struct xfs_dir3_free_hdr));
 269         memset(&hdr, 0, sizeof(hdr));
 270 
 271         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 272                 struct xfs_dir3_free_hdr *hdr3 = bp->b_addr;
 273 
 274                 hdr.magic = XFS_DIR3_FREE_MAGIC;
 275 
 276                 hdr3->hdr.blkno = cpu_to_be64(bp->b_bn);
 277                 hdr3->hdr.owner = cpu_to_be64(dp->i_ino);
 278                 uuid_copy(&hdr3->hdr.uuid, &mp->m_sb.sb_meta_uuid);
 279         } else
 280                 hdr.magic = XFS_DIR2_FREE_MAGIC;
 281         dp->d_ops->free_hdr_to_disk(bp->b_addr, &hdr);
 282         *bpp = bp;
 283         return 0;
 284 }
 285 
 286 /*
 287  * Log entries from a freespace block.
 288  */
 289 STATIC void
 290 xfs_dir2_free_log_bests(
 291         struct xfs_da_args      *args,
 292         struct xfs_buf          *bp,
 293         int                     first,          /* first entry to log */
 294         int                     last)           /* last entry to log */
 295 {
 296         xfs_dir2_free_t         *free;          /* freespace structure */
 297         __be16                  *bests;
 298 
 299         free = bp->b_addr;
 300         bests = args->dp->d_ops->free_bests_p(free);
 301         ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC) ||
 302                free->hdr.magic == cpu_to_be32(XFS_DIR3_FREE_MAGIC));
 303         xfs_trans_log_buf(args->trans, bp,
 304                 (uint)((char *)&bests[first] - (char *)free),
 305                 (uint)((char *)&bests[last] - (char *)free +
 306                        sizeof(bests[0]) - 1));
 307 }
 308 
 309 /*
 310  * Log header from a freespace block.
 311  */
 312 static void
 313 xfs_dir2_free_log_header(
 314         struct xfs_da_args      *args,
 315         struct xfs_buf          *bp)
 316 {
 317 #ifdef DEBUG
 318         xfs_dir2_free_t         *free;          /* freespace structure */
 319 
 320         free = bp->b_addr;
 321         ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC) ||
 322                free->hdr.magic == cpu_to_be32(XFS_DIR3_FREE_MAGIC));
 323 #endif
 324         xfs_trans_log_buf(args->trans, bp, 0,
 325                           args->dp->d_ops->free_hdr_size - 1);
 326 }
 327 
 328 /*
 329  * Convert a leaf-format directory to a node-format directory.
 330  * We need to change the magic number of the leaf block, and copy
 331  * the freespace table out of the leaf block into its own block.
 332  */
 333 int                                             /* error */
 334 xfs_dir2_leaf_to_node(
 335         xfs_da_args_t           *args,          /* operation arguments */
 336         struct xfs_buf          *lbp)           /* leaf buffer */
 337 {
 338         xfs_inode_t             *dp;            /* incore directory inode */
 339         int                     error;          /* error return value */
 340         struct xfs_buf          *fbp;           /* freespace buffer */
 341         xfs_dir2_db_t           fdb;            /* freespace block number */
 342         xfs_dir2_free_t         *free;          /* freespace structure */
 343         __be16                  *from;          /* pointer to freespace entry */
 344         int                     i;              /* leaf freespace index */
 345         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 346         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
 347         int                     n;              /* count of live freespc ents */
 348         xfs_dir2_data_off_t     off;            /* freespace entry value */
 349         __be16                  *to;            /* pointer to freespace entry */
 350         xfs_trans_t             *tp;            /* transaction pointer */
 351         struct xfs_dir3_icfree_hdr freehdr;
 352 
 353         trace_xfs_dir2_leaf_to_node(args);
 354 
 355         dp = args->dp;
 356         tp = args->trans;
 357         /*
 358          * Add a freespace block to the directory.
 359          */
 360         if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_FREE_SPACE, &fdb))) {
 361                 return error;
 362         }
 363         ASSERT(fdb == xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET));
 364         /*
 365          * Get the buffer for the new freespace block.
 366          */
 367         error = xfs_dir3_free_get_buf(args, fdb, &fbp);
 368         if (error)
 369                 return error;
 370 
 371         free = fbp->b_addr;
 372         dp->d_ops->free_hdr_from_disk(&freehdr, free);
 373         leaf = lbp->b_addr;
 374         ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
 375         if (be32_to_cpu(ltp->bestcount) >
 376                                 (uint)dp->i_d.di_size / args->geo->blksize)
 377                 return -EFSCORRUPTED;
 378 
 379         /*
 380          * Copy freespace entries from the leaf block to the new block.
 381          * Count active entries.
 382          */
 383         from = xfs_dir2_leaf_bests_p(ltp);
 384         to = dp->d_ops->free_bests_p(free);
 385         for (i = n = 0; i < be32_to_cpu(ltp->bestcount); i++, from++, to++) {
 386                 if ((off = be16_to_cpu(*from)) != NULLDATAOFF)
 387                         n++;
 388                 *to = cpu_to_be16(off);
 389         }
 390 
 391         /*
 392          * Now initialize the freespace block header.
 393          */
 394         freehdr.nused = n;
 395         freehdr.nvalid = be32_to_cpu(ltp->bestcount);
 396 
 397         dp->d_ops->free_hdr_to_disk(fbp->b_addr, &freehdr);
 398         xfs_dir2_free_log_bests(args, fbp, 0, freehdr.nvalid - 1);
 399         xfs_dir2_free_log_header(args, fbp);
 400 
 401         /*
 402          * Converting the leaf to a leafnode is just a matter of changing the
 403          * magic number and the ops. Do the change directly to the buffer as
 404          * it's less work (and less code) than decoding the header to host
 405          * format and back again.
 406          */
 407         if (leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC))
 408                 leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAFN_MAGIC);
 409         else
 410                 leaf->hdr.info.magic = cpu_to_be16(XFS_DIR3_LEAFN_MAGIC);
 411         lbp->b_ops = &xfs_dir3_leafn_buf_ops;
 412         xfs_trans_buf_set_type(tp, lbp, XFS_BLFT_DIR_LEAFN_BUF);
 413         xfs_dir3_leaf_log_header(args, lbp);
 414         xfs_dir3_leaf_check(dp, lbp);
 415         return 0;
 416 }
 417 
 418 /*
 419  * Add a leaf entry to a leaf block in a node-form directory.
 420  * The other work necessary is done from the caller.
 421  */
 422 static int                                      /* error */
 423 xfs_dir2_leafn_add(
 424         struct xfs_buf          *bp,            /* leaf buffer */
 425         struct xfs_da_args      *args,          /* operation arguments */
 426         int                     index)          /* insertion pt for new entry */
 427 {
 428         struct xfs_dir3_icleaf_hdr leafhdr;
 429         struct xfs_inode        *dp = args->dp;
 430         struct xfs_dir2_leaf    *leaf = bp->b_addr;
 431         struct xfs_dir2_leaf_entry *lep;
 432         struct xfs_dir2_leaf_entry *ents;
 433         int                     compact;        /* compacting stale leaves */
 434         int                     highstale = 0;  /* next stale entry */
 435         int                     lfloghigh;      /* high leaf entry logging */
 436         int                     lfloglow;       /* low leaf entry logging */
 437         int                     lowstale = 0;   /* previous stale entry */
 438 
 439         trace_xfs_dir2_leafn_add(args, index);
 440 
 441         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 442         ents = dp->d_ops->leaf_ents_p(leaf);
 443 
 444         /*
 445          * Quick check just to make sure we are not going to index
 446          * into other peoples memory
 447          */
 448         if (index < 0)
 449                 return -EFSCORRUPTED;
 450 
 451         /*
 452          * If there are already the maximum number of leaf entries in
 453          * the block, if there are no stale entries it won't fit.
 454          * Caller will do a split.  If there are stale entries we'll do
 455          * a compact.
 456          */
 457 
 458         if (leafhdr.count == dp->d_ops->leaf_max_ents(args->geo)) {
 459                 if (!leafhdr.stale)
 460                         return -ENOSPC;
 461                 compact = leafhdr.stale > 1;
 462         } else
 463                 compact = 0;
 464         ASSERT(index == 0 || be32_to_cpu(ents[index - 1].hashval) <= args->hashval);
 465         ASSERT(index == leafhdr.count ||
 466                be32_to_cpu(ents[index].hashval) >= args->hashval);
 467 
 468         if (args->op_flags & XFS_DA_OP_JUSTCHECK)
 469                 return 0;
 470 
 471         /*
 472          * Compact out all but one stale leaf entry.  Leaves behind
 473          * the entry closest to index.
 474          */
 475         if (compact)
 476                 xfs_dir3_leaf_compact_x1(&leafhdr, ents, &index, &lowstale,
 477                                          &highstale, &lfloglow, &lfloghigh);
 478         else if (leafhdr.stale) {
 479                 /*
 480                  * Set impossible logging indices for this case.
 481                  */
 482                 lfloglow = leafhdr.count;
 483                 lfloghigh = -1;
 484         }
 485 
 486         /*
 487          * Insert the new entry, log everything.
 488          */
 489         lep = xfs_dir3_leaf_find_entry(&leafhdr, ents, index, compact, lowstale,
 490                                        highstale, &lfloglow, &lfloghigh);
 491 
 492         lep->hashval = cpu_to_be32(args->hashval);
 493         lep->address = cpu_to_be32(xfs_dir2_db_off_to_dataptr(args->geo,
 494                                 args->blkno, args->index));
 495 
 496         dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
 497         xfs_dir3_leaf_log_header(args, bp);
 498         xfs_dir3_leaf_log_ents(args, bp, lfloglow, lfloghigh);
 499         xfs_dir3_leaf_check(dp, bp);
 500         return 0;
 501 }
 502 
 503 #ifdef DEBUG
 504 static void
 505 xfs_dir2_free_hdr_check(
 506         struct xfs_inode *dp,
 507         struct xfs_buf  *bp,
 508         xfs_dir2_db_t   db)
 509 {
 510         struct xfs_dir3_icfree_hdr hdr;
 511 
 512         dp->d_ops->free_hdr_from_disk(&hdr, bp->b_addr);
 513 
 514         ASSERT((hdr.firstdb %
 515                 dp->d_ops->free_max_bests(dp->i_mount->m_dir_geo)) == 0);
 516         ASSERT(hdr.firstdb <= db);
 517         ASSERT(db < hdr.firstdb + hdr.nvalid);
 518 }
 519 #else
 520 #define xfs_dir2_free_hdr_check(dp, bp, db)
 521 #endif  /* DEBUG */
 522 
 523 /*
 524  * Return the last hash value in the leaf.
 525  * Stale entries are ok.
 526  */
 527 xfs_dahash_t                                    /* hash value */
 528 xfs_dir2_leaf_lasthash(
 529         struct xfs_inode *dp,
 530         struct xfs_buf  *bp,                    /* leaf buffer */
 531         int             *count)                 /* count of entries in leaf */
 532 {
 533         struct xfs_dir2_leaf    *leaf = bp->b_addr;
 534         struct xfs_dir2_leaf_entry *ents;
 535         struct xfs_dir3_icleaf_hdr leafhdr;
 536 
 537         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 538 
 539         ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
 540                leafhdr.magic == XFS_DIR3_LEAFN_MAGIC ||
 541                leafhdr.magic == XFS_DIR2_LEAF1_MAGIC ||
 542                leafhdr.magic == XFS_DIR3_LEAF1_MAGIC);
 543 
 544         if (count)
 545                 *count = leafhdr.count;
 546         if (!leafhdr.count)
 547                 return 0;
 548 
 549         ents = dp->d_ops->leaf_ents_p(leaf);
 550         return be32_to_cpu(ents[leafhdr.count - 1].hashval);
 551 }
 552 
 553 /*
 554  * Look up a leaf entry for space to add a name in a node-format leaf block.
 555  * The extrablk in state is a freespace block.
 556  */
 557 STATIC int
 558 xfs_dir2_leafn_lookup_for_addname(
 559         struct xfs_buf          *bp,            /* leaf buffer */
 560         xfs_da_args_t           *args,          /* operation arguments */
 561         int                     *indexp,        /* out: leaf entry index */
 562         xfs_da_state_t          *state)         /* state to fill in */
 563 {
 564         struct xfs_buf          *curbp = NULL;  /* current data/free buffer */
 565         xfs_dir2_db_t           curdb = -1;     /* current data block number */
 566         xfs_dir2_db_t           curfdb = -1;    /* current free block number */
 567         xfs_inode_t             *dp;            /* incore directory inode */
 568         int                     error;          /* error return value */
 569         int                     fi;             /* free entry index */
 570         xfs_dir2_free_t         *free = NULL;   /* free block structure */
 571         int                     index;          /* leaf entry index */
 572         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 573         int                     length;         /* length of new data entry */
 574         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 575         xfs_mount_t             *mp;            /* filesystem mount point */
 576         xfs_dir2_db_t           newdb;          /* new data block number */
 577         xfs_dir2_db_t           newfdb;         /* new free block number */
 578         xfs_trans_t             *tp;            /* transaction pointer */
 579         struct xfs_dir2_leaf_entry *ents;
 580         struct xfs_dir3_icleaf_hdr leafhdr;
 581 
 582         dp = args->dp;
 583         tp = args->trans;
 584         mp = dp->i_mount;
 585         leaf = bp->b_addr;
 586         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 587         ents = dp->d_ops->leaf_ents_p(leaf);
 588 
 589         xfs_dir3_leaf_check(dp, bp);
 590         ASSERT(leafhdr.count > 0);
 591 
 592         /*
 593          * Look up the hash value in the leaf entries.
 594          */
 595         index = xfs_dir2_leaf_search_hash(args, bp);
 596         /*
 597          * Do we have a buffer coming in?
 598          */
 599         if (state->extravalid) {
 600                 /* If so, it's a free block buffer, get the block number. */
 601                 curbp = state->extrablk.bp;
 602                 curfdb = state->extrablk.blkno;
 603                 free = curbp->b_addr;
 604                 ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC) ||
 605                        free->hdr.magic == cpu_to_be32(XFS_DIR3_FREE_MAGIC));
 606         }
 607         length = dp->d_ops->data_entsize(args->namelen);
 608         /*
 609          * Loop over leaf entries with the right hash value.
 610          */
 611         for (lep = &ents[index];
 612              index < leafhdr.count && be32_to_cpu(lep->hashval) == args->hashval;
 613              lep++, index++) {
 614                 /*
 615                  * Skip stale leaf entries.
 616                  */
 617                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 618                         continue;
 619                 /*
 620                  * Pull the data block number from the entry.
 621                  */
 622                 newdb = xfs_dir2_dataptr_to_db(args->geo,
 623                                                be32_to_cpu(lep->address));
 624                 /*
 625                  * For addname, we're looking for a place to put the new entry.
 626                  * We want to use a data block with an entry of equal
 627                  * hash value to ours if there is one with room.
 628                  *
 629                  * If this block isn't the data block we already have
 630                  * in hand, take a look at it.
 631                  */
 632                 if (newdb != curdb) {
 633                         __be16 *bests;
 634 
 635                         curdb = newdb;
 636                         /*
 637                          * Convert the data block to the free block
 638                          * holding its freespace information.
 639                          */
 640                         newfdb = dp->d_ops->db_to_fdb(args->geo, newdb);
 641                         /*
 642                          * If it's not the one we have in hand, read it in.
 643                          */
 644                         if (newfdb != curfdb) {
 645                                 /*
 646                                  * If we had one before, drop it.
 647                                  */
 648                                 if (curbp)
 649                                         xfs_trans_brelse(tp, curbp);
 650 
 651                                 error = xfs_dir2_free_read(tp, dp,
 652                                                 xfs_dir2_db_to_da(args->geo,
 653                                                                   newfdb),
 654                                                 &curbp);
 655                                 if (error)
 656                                         return error;
 657                                 free = curbp->b_addr;
 658 
 659                                 xfs_dir2_free_hdr_check(dp, curbp, curdb);
 660                         }
 661                         /*
 662                          * Get the index for our entry.
 663                          */
 664                         fi = dp->d_ops->db_to_fdindex(args->geo, curdb);
 665                         /*
 666                          * If it has room, return it.
 667                          */
 668                         bests = dp->d_ops->free_bests_p(free);
 669                         if (unlikely(bests[fi] == cpu_to_be16(NULLDATAOFF))) {
 670                                 XFS_ERROR_REPORT("xfs_dir2_leafn_lookup_int",
 671                                                         XFS_ERRLEVEL_LOW, mp);
 672                                 if (curfdb != newfdb)
 673                                         xfs_trans_brelse(tp, curbp);
 674                                 return -EFSCORRUPTED;
 675                         }
 676                         curfdb = newfdb;
 677                         if (be16_to_cpu(bests[fi]) >= length)
 678                                 goto out;
 679                 }
 680         }
 681         /* Didn't find any space */
 682         fi = -1;
 683 out:
 684         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
 685         if (curbp) {
 686                 /* Giving back a free block. */
 687                 state->extravalid = 1;
 688                 state->extrablk.bp = curbp;
 689                 state->extrablk.index = fi;
 690                 state->extrablk.blkno = curfdb;
 691 
 692                 /*
 693                  * Important: this magic number is not in the buffer - it's for
 694                  * buffer type information and therefore only the free/data type
 695                  * matters here, not whether CRCs are enabled or not.
 696                  */
 697                 state->extrablk.magic = XFS_DIR2_FREE_MAGIC;
 698         } else {
 699                 state->extravalid = 0;
 700         }
 701         /*
 702          * Return the index, that will be the insertion point.
 703          */
 704         *indexp = index;
 705         return -ENOENT;
 706 }
 707 
 708 /*
 709  * Look up a leaf entry in a node-format leaf block.
 710  * The extrablk in state a data block.
 711  */
 712 STATIC int
 713 xfs_dir2_leafn_lookup_for_entry(
 714         struct xfs_buf          *bp,            /* leaf buffer */
 715         xfs_da_args_t           *args,          /* operation arguments */
 716         int                     *indexp,        /* out: leaf entry index */
 717         xfs_da_state_t          *state)         /* state to fill in */
 718 {
 719         struct xfs_buf          *curbp = NULL;  /* current data/free buffer */
 720         xfs_dir2_db_t           curdb = -1;     /* current data block number */
 721         xfs_dir2_data_entry_t   *dep;           /* data block entry */
 722         xfs_inode_t             *dp;            /* incore directory inode */
 723         int                     error;          /* error return value */
 724         int                     index;          /* leaf entry index */
 725         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 726         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 727         xfs_mount_t             *mp;            /* filesystem mount point */
 728         xfs_dir2_db_t           newdb;          /* new data block number */
 729         xfs_trans_t             *tp;            /* transaction pointer */
 730         enum xfs_dacmp          cmp;            /* comparison result */
 731         struct xfs_dir2_leaf_entry *ents;
 732         struct xfs_dir3_icleaf_hdr leafhdr;
 733 
 734         dp = args->dp;
 735         tp = args->trans;
 736         mp = dp->i_mount;
 737         leaf = bp->b_addr;
 738         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 739         ents = dp->d_ops->leaf_ents_p(leaf);
 740 
 741         xfs_dir3_leaf_check(dp, bp);
 742         if (leafhdr.count <= 0)
 743                 return -EFSCORRUPTED;
 744 
 745         /*
 746          * Look up the hash value in the leaf entries.
 747          */
 748         index = xfs_dir2_leaf_search_hash(args, bp);
 749         /*
 750          * Do we have a buffer coming in?
 751          */
 752         if (state->extravalid) {
 753                 curbp = state->extrablk.bp;
 754                 curdb = state->extrablk.blkno;
 755         }
 756         /*
 757          * Loop over leaf entries with the right hash value.
 758          */
 759         for (lep = &ents[index];
 760              index < leafhdr.count && be32_to_cpu(lep->hashval) == args->hashval;
 761              lep++, index++) {
 762                 /*
 763                  * Skip stale leaf entries.
 764                  */
 765                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 766                         continue;
 767                 /*
 768                  * Pull the data block number from the entry.
 769                  */
 770                 newdb = xfs_dir2_dataptr_to_db(args->geo,
 771                                                be32_to_cpu(lep->address));
 772                 /*
 773                  * Not adding a new entry, so we really want to find
 774                  * the name given to us.
 775                  *
 776                  * If it's a different data block, go get it.
 777                  */
 778                 if (newdb != curdb) {
 779                         /*
 780                          * If we had a block before that we aren't saving
 781                          * for a CI name, drop it
 782                          */
 783                         if (curbp && (args->cmpresult == XFS_CMP_DIFFERENT ||
 784                                                 curdb != state->extrablk.blkno))
 785                                 xfs_trans_brelse(tp, curbp);
 786                         /*
 787                          * If needing the block that is saved with a CI match,
 788                          * use it otherwise read in the new data block.
 789                          */
 790                         if (args->cmpresult != XFS_CMP_DIFFERENT &&
 791                                         newdb == state->extrablk.blkno) {
 792                                 ASSERT(state->extravalid);
 793                                 curbp = state->extrablk.bp;
 794                         } else {
 795                                 error = xfs_dir3_data_read(tp, dp,
 796                                                 xfs_dir2_db_to_da(args->geo,
 797                                                                   newdb),
 798                                                 -1, &curbp);
 799                                 if (error)
 800                                         return error;
 801                         }
 802                         xfs_dir3_data_check(dp, curbp);
 803                         curdb = newdb;
 804                 }
 805                 /*
 806                  * Point to the data entry.
 807                  */
 808                 dep = (xfs_dir2_data_entry_t *)((char *)curbp->b_addr +
 809                         xfs_dir2_dataptr_to_off(args->geo,
 810                                                 be32_to_cpu(lep->address)));
 811                 /*
 812                  * Compare the entry and if it's an exact match, return
 813                  * EEXIST immediately. If it's the first case-insensitive
 814                  * match, store the block & inode number and continue looking.
 815                  */
 816                 cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
 817                 if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 818                         /* If there is a CI match block, drop it */
 819                         if (args->cmpresult != XFS_CMP_DIFFERENT &&
 820                                                 curdb != state->extrablk.blkno)
 821                                 xfs_trans_brelse(tp, state->extrablk.bp);
 822                         args->cmpresult = cmp;
 823                         args->inumber = be64_to_cpu(dep->inumber);
 824                         args->filetype = dp->d_ops->data_get_ftype(dep);
 825                         *indexp = index;
 826                         state->extravalid = 1;
 827                         state->extrablk.bp = curbp;
 828                         state->extrablk.blkno = curdb;
 829                         state->extrablk.index = (int)((char *)dep -
 830                                                         (char *)curbp->b_addr);
 831                         state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
 832                         curbp->b_ops = &xfs_dir3_data_buf_ops;
 833                         xfs_trans_buf_set_type(tp, curbp, XFS_BLFT_DIR_DATA_BUF);
 834                         if (cmp == XFS_CMP_EXACT)
 835                                 return -EEXIST;
 836                 }
 837         }
 838         ASSERT(index == leafhdr.count || (args->op_flags & XFS_DA_OP_OKNOENT));
 839         if (curbp) {
 840                 if (args->cmpresult == XFS_CMP_DIFFERENT) {
 841                         /* Giving back last used data block. */
 842                         state->extravalid = 1;
 843                         state->extrablk.bp = curbp;
 844                         state->extrablk.index = -1;
 845                         state->extrablk.blkno = curdb;
 846                         state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
 847                         curbp->b_ops = &xfs_dir3_data_buf_ops;
 848                         xfs_trans_buf_set_type(tp, curbp, XFS_BLFT_DIR_DATA_BUF);
 849                 } else {
 850                         /* If the curbp is not the CI match block, drop it */
 851                         if (state->extrablk.bp != curbp)
 852                                 xfs_trans_brelse(tp, curbp);
 853                 }
 854         } else {
 855                 state->extravalid = 0;
 856         }
 857         *indexp = index;
 858         return -ENOENT;
 859 }
 860 
 861 /*
 862  * Look up a leaf entry in a node-format leaf block.
 863  * If this is an addname then the extrablk in state is a freespace block,
 864  * otherwise it's a data block.
 865  */
 866 int
 867 xfs_dir2_leafn_lookup_int(
 868         struct xfs_buf          *bp,            /* leaf buffer */
 869         xfs_da_args_t           *args,          /* operation arguments */
 870         int                     *indexp,        /* out: leaf entry index */
 871         xfs_da_state_t          *state)         /* state to fill in */
 872 {
 873         if (args->op_flags & XFS_DA_OP_ADDNAME)
 874                 return xfs_dir2_leafn_lookup_for_addname(bp, args, indexp,
 875                                                         state);
 876         return xfs_dir2_leafn_lookup_for_entry(bp, args, indexp, state);
 877 }
 878 
 879 /*
 880  * Move count leaf entries from source to destination leaf.
 881  * Log entries and headers.  Stale entries are preserved.
 882  */
 883 static void
 884 xfs_dir3_leafn_moveents(
 885         xfs_da_args_t                   *args,  /* operation arguments */
 886         struct xfs_buf                  *bp_s,  /* source */
 887         struct xfs_dir3_icleaf_hdr      *shdr,
 888         struct xfs_dir2_leaf_entry      *sents,
 889         int                             start_s,/* source leaf index */
 890         struct xfs_buf                  *bp_d,  /* destination */
 891         struct xfs_dir3_icleaf_hdr      *dhdr,
 892         struct xfs_dir2_leaf_entry      *dents,
 893         int                             start_d,/* destination leaf index */
 894         int                             count)  /* count of leaves to copy */
 895 {
 896         int                             stale;  /* count stale leaves copied */
 897 
 898         trace_xfs_dir2_leafn_moveents(args, start_s, start_d, count);
 899 
 900         /*
 901          * Silently return if nothing to do.
 902          */
 903         if (count == 0)
 904                 return;
 905 
 906         /*
 907          * If the destination index is not the end of the current
 908          * destination leaf entries, open up a hole in the destination
 909          * to hold the new entries.
 910          */
 911         if (start_d < dhdr->count) {
 912                 memmove(&dents[start_d + count], &dents[start_d],
 913                         (dhdr->count - start_d) * sizeof(xfs_dir2_leaf_entry_t));
 914                 xfs_dir3_leaf_log_ents(args, bp_d, start_d + count,
 915                                        count + dhdr->count - 1);
 916         }
 917         /*
 918          * If the source has stale leaves, count the ones in the copy range
 919          * so we can update the header correctly.
 920          */
 921         if (shdr->stale) {
 922                 int     i;                      /* temp leaf index */
 923 
 924                 for (i = start_s, stale = 0; i < start_s + count; i++) {
 925                         if (sents[i].address ==
 926                                         cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 927                                 stale++;
 928                 }
 929         } else
 930                 stale = 0;
 931         /*
 932          * Copy the leaf entries from source to destination.
 933          */
 934         memcpy(&dents[start_d], &sents[start_s],
 935                 count * sizeof(xfs_dir2_leaf_entry_t));
 936         xfs_dir3_leaf_log_ents(args, bp_d, start_d, start_d + count - 1);
 937 
 938         /*
 939          * If there are source entries after the ones we copied,
 940          * delete the ones we copied by sliding the next ones down.
 941          */
 942         if (start_s + count < shdr->count) {
 943                 memmove(&sents[start_s], &sents[start_s + count],
 944                         count * sizeof(xfs_dir2_leaf_entry_t));
 945                 xfs_dir3_leaf_log_ents(args, bp_s, start_s, start_s + count - 1);
 946         }
 947 
 948         /*
 949          * Update the headers and log them.
 950          */
 951         shdr->count -= count;
 952         shdr->stale -= stale;
 953         dhdr->count += count;
 954         dhdr->stale += stale;
 955 }
 956 
 957 /*
 958  * Determine the sort order of two leaf blocks.
 959  * Returns 1 if both are valid and leaf2 should be before leaf1, else 0.
 960  */
 961 int                                             /* sort order */
 962 xfs_dir2_leafn_order(
 963         struct xfs_inode        *dp,
 964         struct xfs_buf          *leaf1_bp,              /* leaf1 buffer */
 965         struct xfs_buf          *leaf2_bp)              /* leaf2 buffer */
 966 {
 967         struct xfs_dir2_leaf    *leaf1 = leaf1_bp->b_addr;
 968         struct xfs_dir2_leaf    *leaf2 = leaf2_bp->b_addr;
 969         struct xfs_dir2_leaf_entry *ents1;
 970         struct xfs_dir2_leaf_entry *ents2;
 971         struct xfs_dir3_icleaf_hdr hdr1;
 972         struct xfs_dir3_icleaf_hdr hdr2;
 973 
 974         dp->d_ops->leaf_hdr_from_disk(&hdr1, leaf1);
 975         dp->d_ops->leaf_hdr_from_disk(&hdr2, leaf2);
 976         ents1 = dp->d_ops->leaf_ents_p(leaf1);
 977         ents2 = dp->d_ops->leaf_ents_p(leaf2);
 978 
 979         if (hdr1.count > 0 && hdr2.count > 0 &&
 980             (be32_to_cpu(ents2[0].hashval) < be32_to_cpu(ents1[0].hashval) ||
 981              be32_to_cpu(ents2[hdr2.count - 1].hashval) <
 982                                 be32_to_cpu(ents1[hdr1.count - 1].hashval)))
 983                 return 1;
 984         return 0;
 985 }
 986 
 987 /*
 988  * Rebalance leaf entries between two leaf blocks.
 989  * This is actually only called when the second block is new,
 990  * though the code deals with the general case.
 991  * A new entry will be inserted in one of the blocks, and that
 992  * entry is taken into account when balancing.
 993  */
 994 static void
 995 xfs_dir2_leafn_rebalance(
 996         xfs_da_state_t          *state,         /* btree cursor */
 997         xfs_da_state_blk_t      *blk1,          /* first btree block */
 998         xfs_da_state_blk_t      *blk2)          /* second btree block */
 999 {
1000         xfs_da_args_t           *args;          /* operation arguments */
1001         int                     count;          /* count (& direction) leaves */
1002         int                     isleft;         /* new goes in left leaf */
1003         xfs_dir2_leaf_t         *leaf1;         /* first leaf structure */
1004         xfs_dir2_leaf_t         *leaf2;         /* second leaf structure */
1005         int                     mid;            /* midpoint leaf index */
1006 #if defined(DEBUG) || defined(XFS_WARN)
1007         int                     oldstale;       /* old count of stale leaves */
1008 #endif
1009         int                     oldsum;         /* old total leaf count */
1010         int                     swap_blocks;    /* swapped leaf blocks */
1011         struct xfs_dir2_leaf_entry *ents1;
1012         struct xfs_dir2_leaf_entry *ents2;
1013         struct xfs_dir3_icleaf_hdr hdr1;
1014         struct xfs_dir3_icleaf_hdr hdr2;
1015         struct xfs_inode        *dp = state->args->dp;
1016 
1017         args = state->args;
1018         /*
1019          * If the block order is wrong, swap the arguments.
1020          */
1021         swap_blocks = xfs_dir2_leafn_order(dp, blk1->bp, blk2->bp);
1022         if (swap_blocks)
1023                 swap(blk1, blk2);
1024 
1025         leaf1 = blk1->bp->b_addr;
1026         leaf2 = blk2->bp->b_addr;
1027         dp->d_ops->leaf_hdr_from_disk(&hdr1, leaf1);
1028         dp->d_ops->leaf_hdr_from_disk(&hdr2, leaf2);
1029         ents1 = dp->d_ops->leaf_ents_p(leaf1);
1030         ents2 = dp->d_ops->leaf_ents_p(leaf2);
1031 
1032         oldsum = hdr1.count + hdr2.count;
1033 #if defined(DEBUG) || defined(XFS_WARN)
1034         oldstale = hdr1.stale + hdr2.stale;
1035 #endif
1036         mid = oldsum >> 1;
1037 
1038         /*
1039          * If the old leaf count was odd then the new one will be even,
1040          * so we need to divide the new count evenly.
1041          */
1042         if (oldsum & 1) {
1043                 xfs_dahash_t    midhash;        /* middle entry hash value */
1044 
1045                 if (mid >= hdr1.count)
1046                         midhash = be32_to_cpu(ents2[mid - hdr1.count].hashval);
1047                 else
1048                         midhash = be32_to_cpu(ents1[mid].hashval);
1049                 isleft = args->hashval <= midhash;
1050         }
1051         /*
1052          * If the old count is even then the new count is odd, so there's
1053          * no preferred side for the new entry.
1054          * Pick the left one.
1055          */
1056         else
1057                 isleft = 1;
1058         /*
1059          * Calculate moved entry count.  Positive means left-to-right,
1060          * negative means right-to-left.  Then move the entries.
1061          */
1062         count = hdr1.count - mid + (isleft == 0);
1063         if (count > 0)
1064                 xfs_dir3_leafn_moveents(args, blk1->bp, &hdr1, ents1,
1065                                         hdr1.count - count, blk2->bp,
1066                                         &hdr2, ents2, 0, count);
1067         else if (count < 0)
1068                 xfs_dir3_leafn_moveents(args, blk2->bp, &hdr2, ents2, 0,
1069                                         blk1->bp, &hdr1, ents1,
1070                                         hdr1.count, count);
1071 
1072         ASSERT(hdr1.count + hdr2.count == oldsum);
1073         ASSERT(hdr1.stale + hdr2.stale == oldstale);
1074 
1075         /* log the changes made when moving the entries */
1076         dp->d_ops->leaf_hdr_to_disk(leaf1, &hdr1);
1077         dp->d_ops->leaf_hdr_to_disk(leaf2, &hdr2);
1078         xfs_dir3_leaf_log_header(args, blk1->bp);
1079         xfs_dir3_leaf_log_header(args, blk2->bp);
1080 
1081         xfs_dir3_leaf_check(dp, blk1->bp);
1082         xfs_dir3_leaf_check(dp, blk2->bp);
1083 
1084         /*
1085          * Mark whether we're inserting into the old or new leaf.
1086          */
1087         if (hdr1.count < hdr2.count)
1088                 state->inleaf = swap_blocks;
1089         else if (hdr1.count > hdr2.count)
1090                 state->inleaf = !swap_blocks;
1091         else
1092                 state->inleaf = swap_blocks ^ (blk1->index <= hdr1.count);
1093         /*
1094          * Adjust the expected index for insertion.
1095          */
1096         if (!state->inleaf)
1097                 blk2->index = blk1->index - hdr1.count;
1098 
1099         /*
1100          * Finally sanity check just to make sure we are not returning a
1101          * negative index
1102          */
1103         if (blk2->index < 0) {
1104                 state->inleaf = 1;
1105                 blk2->index = 0;
1106                 xfs_alert(dp->i_mount,
1107         "%s: picked the wrong leaf? reverting original leaf: blk1->index %d",
1108                         __func__, blk1->index);
1109         }
1110 }
1111 
1112 static int
1113 xfs_dir3_data_block_free(
1114         xfs_da_args_t           *args,
1115         struct xfs_dir2_data_hdr *hdr,
1116         struct xfs_dir2_free    *free,
1117         xfs_dir2_db_t           fdb,
1118         int                     findex,
1119         struct xfs_buf          *fbp,
1120         int                     longest)
1121 {
1122         int                     logfree = 0;
1123         __be16                  *bests;
1124         struct xfs_dir3_icfree_hdr freehdr;
1125         struct xfs_inode        *dp = args->dp;
1126 
1127         dp->d_ops->free_hdr_from_disk(&freehdr, free);
1128         bests = dp->d_ops->free_bests_p(free);
1129         if (hdr) {
1130                 /*
1131                  * Data block is not empty, just set the free entry to the new
1132                  * value.
1133                  */
1134                 bests[findex] = cpu_to_be16(longest);
1135                 xfs_dir2_free_log_bests(args, fbp, findex, findex);
1136                 return 0;
1137         }
1138 
1139         /* One less used entry in the free table. */
1140         freehdr.nused--;
1141 
1142         /*
1143          * If this was the last entry in the table, we can trim the table size
1144          * back.  There might be other entries at the end referring to
1145          * non-existent data blocks, get those too.
1146          */
1147         if (findex == freehdr.nvalid - 1) {
1148                 int     i;              /* free entry index */
1149 
1150                 for (i = findex - 1; i >= 0; i--) {
1151                         if (bests[i] != cpu_to_be16(NULLDATAOFF))
1152                                 break;
1153                 }
1154                 freehdr.nvalid = i + 1;
1155                 logfree = 0;
1156         } else {
1157                 /* Not the last entry, just punch it out.  */
1158                 bests[findex] = cpu_to_be16(NULLDATAOFF);
1159                 logfree = 1;
1160         }
1161 
1162         dp->d_ops->free_hdr_to_disk(free, &freehdr);
1163         xfs_dir2_free_log_header(args, fbp);
1164 
1165         /*
1166          * If there are no useful entries left in the block, get rid of the
1167          * block if we can.
1168          */
1169         if (!freehdr.nused) {
1170                 int error;
1171 
1172                 error = xfs_dir2_shrink_inode(args, fdb, fbp);
1173                 if (error == 0) {
1174                         fbp = NULL;
1175                         logfree = 0;
1176                 } else if (error != -ENOSPC || args->total != 0)
1177                         return error;
1178                 /*
1179                  * It's possible to get ENOSPC if there is no
1180                  * space reservation.  In this case some one
1181                  * else will eventually get rid of this block.
1182                  */
1183         }
1184 
1185         /* Log the free entry that changed, unless we got rid of it.  */
1186         if (logfree)
1187                 xfs_dir2_free_log_bests(args, fbp, findex, findex);
1188         return 0;
1189 }
1190 
1191 /*
1192  * Remove an entry from a node directory.
1193  * This removes the leaf entry and the data entry,
1194  * and updates the free block if necessary.
1195  */
1196 static int                                      /* error */
1197 xfs_dir2_leafn_remove(
1198         xfs_da_args_t           *args,          /* operation arguments */
1199         struct xfs_buf          *bp,            /* leaf buffer */
1200         int                     index,          /* leaf entry index */
1201         xfs_da_state_blk_t      *dblk,          /* data block */
1202         int                     *rval)          /* resulting block needs join */
1203 {
1204         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
1205         xfs_dir2_db_t           db;             /* data block number */
1206         struct xfs_buf          *dbp;           /* data block buffer */
1207         xfs_dir2_data_entry_t   *dep;           /* data block entry */
1208         xfs_inode_t             *dp;            /* incore directory inode */
1209         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1210         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1211         int                     longest;        /* longest data free entry */
1212         int                     off;            /* data block entry offset */
1213         int                     needlog;        /* need to log data header */
1214         int                     needscan;       /* need to rescan data frees */
1215         xfs_trans_t             *tp;            /* transaction pointer */
1216         struct xfs_dir2_data_free *bf;          /* bestfree table */
1217         struct xfs_dir3_icleaf_hdr leafhdr;
1218         struct xfs_dir2_leaf_entry *ents;
1219 
1220         trace_xfs_dir2_leafn_remove(args, index);
1221 
1222         dp = args->dp;
1223         tp = args->trans;
1224         leaf = bp->b_addr;
1225         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1226         ents = dp->d_ops->leaf_ents_p(leaf);
1227 
1228         /*
1229          * Point to the entry we're removing.
1230          */
1231         lep = &ents[index];
1232 
1233         /*
1234          * Extract the data block and offset from the entry.
1235          */
1236         db = xfs_dir2_dataptr_to_db(args->geo, be32_to_cpu(lep->address));
1237         ASSERT(dblk->blkno == db);
1238         off = xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address));
1239         ASSERT(dblk->index == off);
1240 
1241         /*
1242          * Kill the leaf entry by marking it stale.
1243          * Log the leaf block changes.
1244          */
1245         leafhdr.stale++;
1246         dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
1247         xfs_dir3_leaf_log_header(args, bp);
1248 
1249         lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
1250         xfs_dir3_leaf_log_ents(args, bp, index, index);
1251 
1252         /*
1253          * Make the data entry free.  Keep track of the longest freespace
1254          * in the data block in case it changes.
1255          */
1256         dbp = dblk->bp;
1257         hdr = dbp->b_addr;
1258         dep = (xfs_dir2_data_entry_t *)((char *)hdr + off);
1259         bf = dp->d_ops->data_bestfree_p(hdr);
1260         longest = be16_to_cpu(bf[0].length);
1261         needlog = needscan = 0;
1262         xfs_dir2_data_make_free(args, dbp, off,
1263                 dp->d_ops->data_entsize(dep->namelen), &needlog, &needscan);
1264         /*
1265          * Rescan the data block freespaces for bestfree.
1266          * Log the data block header if needed.
1267          */
1268         if (needscan)
1269                 xfs_dir2_data_freescan(dp, hdr, &needlog);
1270         if (needlog)
1271                 xfs_dir2_data_log_header(args, dbp);
1272         xfs_dir3_data_check(dp, dbp);
1273         /*
1274          * If the longest data block freespace changes, need to update
1275          * the corresponding freeblock entry.
1276          */
1277         if (longest < be16_to_cpu(bf[0].length)) {
1278                 int             error;          /* error return value */
1279                 struct xfs_buf  *fbp;           /* freeblock buffer */
1280                 xfs_dir2_db_t   fdb;            /* freeblock block number */
1281                 int             findex;         /* index in freeblock entries */
1282                 xfs_dir2_free_t *free;          /* freeblock structure */
1283 
1284                 /*
1285                  * Convert the data block number to a free block,
1286                  * read in the free block.
1287                  */
1288                 fdb = dp->d_ops->db_to_fdb(args->geo, db);
1289                 error = xfs_dir2_free_read(tp, dp,
1290                                            xfs_dir2_db_to_da(args->geo, fdb),
1291                                            &fbp);
1292                 if (error)
1293                         return error;
1294                 free = fbp->b_addr;
1295 #ifdef DEBUG
1296         {
1297                 struct xfs_dir3_icfree_hdr freehdr;
1298                 dp->d_ops->free_hdr_from_disk(&freehdr, free);
1299                 ASSERT(freehdr.firstdb == dp->d_ops->free_max_bests(args->geo) *
1300                         (fdb - xfs_dir2_byte_to_db(args->geo,
1301                                                    XFS_DIR2_FREE_OFFSET)));
1302         }
1303 #endif
1304                 /*
1305                  * Calculate which entry we need to fix.
1306                  */
1307                 findex = dp->d_ops->db_to_fdindex(args->geo, db);
1308                 longest = be16_to_cpu(bf[0].length);
1309                 /*
1310                  * If the data block is now empty we can get rid of it
1311                  * (usually).
1312                  */
1313                 if (longest == args->geo->blksize -
1314                                dp->d_ops->data_entry_offset) {
1315                         /*
1316                          * Try to punch out the data block.
1317                          */
1318                         error = xfs_dir2_shrink_inode(args, db, dbp);
1319                         if (error == 0) {
1320                                 dblk->bp = NULL;
1321                                 hdr = NULL;
1322                         }
1323                         /*
1324                          * We can get ENOSPC if there's no space reservation.
1325                          * In this case just drop the buffer and some one else
1326                          * will eventually get rid of the empty block.
1327                          */
1328                         else if (!(error == -ENOSPC && args->total == 0))
1329                                 return error;
1330                 }
1331                 /*
1332                  * If we got rid of the data block, we can eliminate that entry
1333                  * in the free block.
1334                  */
1335                 error = xfs_dir3_data_block_free(args, hdr, free,
1336                                                  fdb, findex, fbp, longest);
1337                 if (error)
1338                         return error;
1339         }
1340 
1341         xfs_dir3_leaf_check(dp, bp);
1342         /*
1343          * Return indication of whether this leaf block is empty enough
1344          * to justify trying to join it with a neighbor.
1345          */
1346         *rval = (dp->d_ops->leaf_hdr_size +
1347                  (uint)sizeof(ents[0]) * (leafhdr.count - leafhdr.stale)) <
1348                 args->geo->magicpct;
1349         return 0;
1350 }
1351 
1352 /*
1353  * Split the leaf entries in the old block into old and new blocks.
1354  */
1355 int                                             /* error */
1356 xfs_dir2_leafn_split(
1357         xfs_da_state_t          *state,         /* btree cursor */
1358         xfs_da_state_blk_t      *oldblk,        /* original block */
1359         xfs_da_state_blk_t      *newblk)        /* newly created block */
1360 {
1361         xfs_da_args_t           *args;          /* operation arguments */
1362         xfs_dablk_t             blkno;          /* new leaf block number */
1363         int                     error;          /* error return value */
1364         struct xfs_inode        *dp;
1365 
1366         /*
1367          * Allocate space for a new leaf node.
1368          */
1369         args = state->args;
1370         dp = args->dp;
1371         ASSERT(oldblk->magic == XFS_DIR2_LEAFN_MAGIC);
1372         error = xfs_da_grow_inode(args, &blkno);
1373         if (error) {
1374                 return error;
1375         }
1376         /*
1377          * Initialize the new leaf block.
1378          */
1379         error = xfs_dir3_leaf_get_buf(args, xfs_dir2_da_to_db(args->geo, blkno),
1380                                       &newblk->bp, XFS_DIR2_LEAFN_MAGIC);
1381         if (error)
1382                 return error;
1383 
1384         newblk->blkno = blkno;
1385         newblk->magic = XFS_DIR2_LEAFN_MAGIC;
1386         /*
1387          * Rebalance the entries across the two leaves, link the new
1388          * block into the leaves.
1389          */
1390         xfs_dir2_leafn_rebalance(state, oldblk, newblk);
1391         error = xfs_da3_blk_link(state, oldblk, newblk);
1392         if (error) {
1393                 return error;
1394         }
1395         /*
1396          * Insert the new entry in the correct block.
1397          */
1398         if (state->inleaf)
1399                 error = xfs_dir2_leafn_add(oldblk->bp, args, oldblk->index);
1400         else
1401                 error = xfs_dir2_leafn_add(newblk->bp, args, newblk->index);
1402         /*
1403          * Update last hashval in each block since we added the name.
1404          */
1405         oldblk->hashval = xfs_dir2_leaf_lasthash(dp, oldblk->bp, NULL);
1406         newblk->hashval = xfs_dir2_leaf_lasthash(dp, newblk->bp, NULL);
1407         xfs_dir3_leaf_check(dp, oldblk->bp);
1408         xfs_dir3_leaf_check(dp, newblk->bp);
1409         return error;
1410 }
1411 
1412 /*
1413  * Check a leaf block and its neighbors to see if the block should be
1414  * collapsed into one or the other neighbor.  Always keep the block
1415  * with the smaller block number.
1416  * If the current block is over 50% full, don't try to join it, return 0.
1417  * If the block is empty, fill in the state structure and return 2.
1418  * If it can be collapsed, fill in the state structure and return 1.
1419  * If nothing can be done, return 0.
1420  */
1421 int                                             /* error */
1422 xfs_dir2_leafn_toosmall(
1423         xfs_da_state_t          *state,         /* btree cursor */
1424         int                     *action)        /* resulting action to take */
1425 {
1426         xfs_da_state_blk_t      *blk;           /* leaf block */
1427         xfs_dablk_t             blkno;          /* leaf block number */
1428         struct xfs_buf          *bp;            /* leaf buffer */
1429         int                     bytes;          /* bytes in use */
1430         int                     count;          /* leaf live entry count */
1431         int                     error;          /* error return value */
1432         int                     forward;        /* sibling block direction */
1433         int                     i;              /* sibling counter */
1434         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1435         int                     rval;           /* result from path_shift */
1436         struct xfs_dir3_icleaf_hdr leafhdr;
1437         struct xfs_dir2_leaf_entry *ents;
1438         struct xfs_inode        *dp = state->args->dp;
1439 
1440         /*
1441          * Check for the degenerate case of the block being over 50% full.
1442          * If so, it's not worth even looking to see if we might be able
1443          * to coalesce with a sibling.
1444          */
1445         blk = &state->path.blk[state->path.active - 1];
1446         leaf = blk->bp->b_addr;
1447         dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1448         ents = dp->d_ops->leaf_ents_p(leaf);
1449         xfs_dir3_leaf_check(dp, blk->bp);
1450 
1451         count = leafhdr.count - leafhdr.stale;
1452         bytes = dp->d_ops->leaf_hdr_size + count * sizeof(ents[0]);
1453         if (bytes > (state->args->geo->blksize >> 1)) {
1454                 /*
1455                  * Blk over 50%, don't try to join.
1456                  */
1457                 *action = 0;
1458                 return 0;
1459         }
1460         /*
1461          * Check for the degenerate case of the block being empty.
1462          * If the block is empty, we'll simply delete it, no need to
1463          * coalesce it with a sibling block.  We choose (arbitrarily)
1464          * to merge with the forward block unless it is NULL.
1465          */
1466         if (count == 0) {
1467                 /*
1468                  * Make altpath point to the block we want to keep and
1469                  * path point to the block we want to drop (this one).
1470                  */
1471                 forward = (leafhdr.forw != 0);
1472                 memcpy(&state->altpath, &state->path, sizeof(state->path));
1473                 error = xfs_da3_path_shift(state, &state->altpath, forward, 0,
1474                         &rval);
1475                 if (error)
1476                         return error;
1477                 *action = rval ? 2 : 0;
1478                 return 0;
1479         }
1480         /*
1481          * Examine each sibling block to see if we can coalesce with
1482          * at least 25% free space to spare.  We need to figure out
1483          * whether to merge with the forward or the backward block.
1484          * We prefer coalescing with the lower numbered sibling so as
1485          * to shrink a directory over time.
1486          */
1487         forward = leafhdr.forw < leafhdr.back;
1488         for (i = 0, bp = NULL; i < 2; forward = !forward, i++) {
1489                 struct xfs_dir3_icleaf_hdr hdr2;
1490 
1491                 blkno = forward ? leafhdr.forw : leafhdr.back;
1492                 if (blkno == 0)
1493                         continue;
1494                 /*
1495                  * Read the sibling leaf block.
1496                  */
1497                 error = xfs_dir3_leafn_read(state->args->trans, dp,
1498                                             blkno, -1, &bp);
1499                 if (error)
1500                         return error;
1501 
1502                 /*
1503                  * Count bytes in the two blocks combined.
1504                  */
1505                 count = leafhdr.count - leafhdr.stale;
1506                 bytes = state->args->geo->blksize -
1507                         (state->args->geo->blksize >> 2);
1508 
1509                 leaf = bp->b_addr;
1510                 dp->d_ops->leaf_hdr_from_disk(&hdr2, leaf);
1511                 ents = dp->d_ops->leaf_ents_p(leaf);
1512                 count += hdr2.count - hdr2.stale;
1513                 bytes -= count * sizeof(ents[0]);
1514 
1515                 /*
1516                  * Fits with at least 25% to spare.
1517                  */
1518                 if (bytes >= 0)
1519                         break;
1520                 xfs_trans_brelse(state->args->trans, bp);
1521         }
1522         /*
1523          * Didn't like either block, give up.
1524          */
1525         if (i >= 2) {
1526                 *action = 0;
1527                 return 0;
1528         }
1529 
1530         /*
1531          * Make altpath point to the block we want to keep (the lower
1532          * numbered block) and path point to the block we want to drop.
1533          */
1534         memcpy(&state->altpath, &state->path, sizeof(state->path));
1535         if (blkno < blk->blkno)
1536                 error = xfs_da3_path_shift(state, &state->altpath, forward, 0,
1537                         &rval);
1538         else
1539                 error = xfs_da3_path_shift(state, &state->path, forward, 0,
1540                         &rval);
1541         if (error) {
1542                 return error;
1543         }
1544         *action = rval ? 0 : 1;
1545         return 0;
1546 }
1547 
1548 /*
1549  * Move all the leaf entries from drop_blk to save_blk.
1550  * This is done as part of a join operation.
1551  */
1552 void
1553 xfs_dir2_leafn_unbalance(
1554         xfs_da_state_t          *state,         /* cursor */
1555         xfs_da_state_blk_t      *drop_blk,      /* dead block */
1556         xfs_da_state_blk_t      *save_blk)      /* surviving block */
1557 {
1558         xfs_da_args_t           *args;          /* operation arguments */
1559         xfs_dir2_leaf_t         *drop_leaf;     /* dead leaf structure */
1560         xfs_dir2_leaf_t         *save_leaf;     /* surviving leaf structure */
1561         struct xfs_dir3_icleaf_hdr savehdr;
1562         struct xfs_dir3_icleaf_hdr drophdr;
1563         struct xfs_dir2_leaf_entry *sents;
1564         struct xfs_dir2_leaf_entry *dents;
1565         struct xfs_inode        *dp = state->args->dp;
1566 
1567         args = state->args;
1568         ASSERT(drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1569         ASSERT(save_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1570         drop_leaf = drop_blk->bp->b_addr;
1571         save_leaf = save_blk->bp->b_addr;
1572 
1573         dp->d_ops->leaf_hdr_from_disk(&savehdr, save_leaf);
1574         dp->d_ops->leaf_hdr_from_disk(&drophdr, drop_leaf);
1575         sents = dp->d_ops->leaf_ents_p(save_leaf);
1576         dents = dp->d_ops->leaf_ents_p(drop_leaf);
1577 
1578         /*
1579          * If there are any stale leaf entries, take this opportunity
1580          * to purge them.
1581          */
1582         if (drophdr.stale)
1583                 xfs_dir3_leaf_compact(args, &drophdr, drop_blk->bp);
1584         if (savehdr.stale)
1585                 xfs_dir3_leaf_compact(args, &savehdr, save_blk->bp);
1586 
1587         /*
1588          * Move the entries from drop to the appropriate end of save.
1589          */
1590         drop_blk->hashval = be32_to_cpu(dents[drophdr.count - 1].hashval);
1591         if (xfs_dir2_leafn_order(dp, save_blk->bp, drop_blk->bp))
1592                 xfs_dir3_leafn_moveents(args, drop_blk->bp, &drophdr, dents, 0,
1593                                         save_blk->bp, &savehdr, sents, 0,
1594                                         drophdr.count);
1595         else
1596                 xfs_dir3_leafn_moveents(args, drop_blk->bp, &drophdr, dents, 0,
1597                                         save_blk->bp, &savehdr, sents,
1598                                         savehdr.count, drophdr.count);
1599         save_blk->hashval = be32_to_cpu(sents[savehdr.count - 1].hashval);
1600 
1601         /* log the changes made when moving the entries */
1602         dp->d_ops->leaf_hdr_to_disk(save_leaf, &savehdr);
1603         dp->d_ops->leaf_hdr_to_disk(drop_leaf, &drophdr);
1604         xfs_dir3_leaf_log_header(args, save_blk->bp);
1605         xfs_dir3_leaf_log_header(args, drop_blk->bp);
1606 
1607         xfs_dir3_leaf_check(dp, save_blk->bp);
1608         xfs_dir3_leaf_check(dp, drop_blk->bp);
1609 }
1610 
1611 /*
1612  * Add a new data block to the directory at the free space index that the caller
1613  * has specified.
1614  */
1615 static int
1616 xfs_dir2_node_add_datablk(
1617         struct xfs_da_args      *args,
1618         struct xfs_da_state_blk *fblk,
1619         xfs_dir2_db_t           *dbno,
1620         struct xfs_buf          **dbpp,
1621         struct xfs_buf          **fbpp,
1622         int                     *findex)
1623 {
1624         struct xfs_inode        *dp = args->dp;
1625         struct xfs_trans        *tp = args->trans;
1626         struct xfs_mount        *mp = dp->i_mount;
1627         struct xfs_dir3_icfree_hdr freehdr;
1628         struct xfs_dir2_data_free *bf;
1629         struct xfs_dir2_data_hdr *hdr;
1630         struct xfs_dir2_free    *free = NULL;
1631         xfs_dir2_db_t           fbno;
1632         struct xfs_buf          *fbp;
1633         struct xfs_buf          *dbp;
1634         __be16                  *bests = NULL;
1635         int                     error;
1636 
1637         /* Not allowed to allocate, return failure. */
1638         if (args->total == 0)
1639                 return -ENOSPC;
1640 
1641         /* Allocate and initialize the new data block.  */
1642         error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE, dbno);
1643         if (error)
1644                 return error;
1645         error = xfs_dir3_data_init(args, *dbno, &dbp);
1646         if (error)
1647                 return error;
1648 
1649         /*
1650          * Get the freespace block corresponding to the data block
1651          * that was just allocated.
1652          */
1653         fbno = dp->d_ops->db_to_fdb(args->geo, *dbno);
1654         error = xfs_dir2_free_try_read(tp, dp,
1655                                xfs_dir2_db_to_da(args->geo, fbno), &fbp);
1656         if (error)
1657                 return error;
1658 
1659         /*
1660          * If there wasn't a freespace block, the read will
1661          * return a NULL fbp.  Allocate and initialize a new one.
1662          */
1663         if (!fbp) {
1664                 error = xfs_dir2_grow_inode(args, XFS_DIR2_FREE_SPACE, &fbno);
1665                 if (error)
1666                         return error;
1667 
1668                 if (dp->d_ops->db_to_fdb(args->geo, *dbno) != fbno) {
1669                         xfs_alert(mp,
1670 "%s: dir ino %llu needed freesp block %lld for data block %lld, got %lld",
1671                                 __func__, (unsigned long long)dp->i_ino,
1672                                 (long long)dp->d_ops->db_to_fdb(args->geo, *dbno),
1673                                 (long long)*dbno, (long long)fbno);
1674                         if (fblk) {
1675                                 xfs_alert(mp,
1676                         " fblk "PTR_FMT" blkno %llu index %d magic 0x%x",
1677                                         fblk, (unsigned long long)fblk->blkno,
1678                                         fblk->index, fblk->magic);
1679                         } else {
1680                                 xfs_alert(mp, " ... fblk is NULL");
1681                         }
1682                         XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
1683                         return -EFSCORRUPTED;
1684                 }
1685 
1686                 /* Get a buffer for the new block. */
1687                 error = xfs_dir3_free_get_buf(args, fbno, &fbp);
1688                 if (error)
1689                         return error;
1690                 free = fbp->b_addr;
1691                 bests = dp->d_ops->free_bests_p(free);
1692                 dp->d_ops->free_hdr_from_disk(&freehdr, free);
1693 
1694                 /* Remember the first slot as our empty slot. */
1695                 freehdr.firstdb = (fbno - xfs_dir2_byte_to_db(args->geo,
1696                                                         XFS_DIR2_FREE_OFFSET)) *
1697                                 dp->d_ops->free_max_bests(args->geo);
1698         } else {
1699                 free = fbp->b_addr;
1700                 bests = dp->d_ops->free_bests_p(free);
1701                 dp->d_ops->free_hdr_from_disk(&freehdr, free);
1702         }
1703 
1704         /* Set the freespace block index from the data block number. */
1705         *findex = dp->d_ops->db_to_fdindex(args->geo, *dbno);
1706 
1707         /* Extend the freespace table if the new data block is off the end. */
1708         if (*findex >= freehdr.nvalid) {
1709                 ASSERT(*findex < dp->d_ops->free_max_bests(args->geo));
1710                 freehdr.nvalid = *findex + 1;
1711                 bests[*findex] = cpu_to_be16(NULLDATAOFF);
1712         }
1713 
1714         /*
1715          * If this entry was for an empty data block (this should always be
1716          * true) then update the header.
1717          */
1718         if (bests[*findex] == cpu_to_be16(NULLDATAOFF)) {
1719                 freehdr.nused++;
1720                 dp->d_ops->free_hdr_to_disk(fbp->b_addr, &freehdr);
1721                 xfs_dir2_free_log_header(args, fbp);
1722         }
1723 
1724         /* Update the freespace value for the new block in the table. */
1725         hdr = dbp->b_addr;
1726         bf = dp->d_ops->data_bestfree_p(hdr);
1727         bests[*findex] = bf[0].length;
1728 
1729         *dbpp = dbp;
1730         *fbpp = fbp;
1731         return 0;
1732 }
1733 
1734 static int
1735 xfs_dir2_node_find_freeblk(
1736         struct xfs_da_args      *args,
1737         struct xfs_da_state_blk *fblk,
1738         xfs_dir2_db_t           *dbnop,
1739         struct xfs_buf          **fbpp,
1740         int                     *findexp,
1741         int                     length)
1742 {
1743         struct xfs_dir3_icfree_hdr freehdr;
1744         struct xfs_dir2_free    *free = NULL;
1745         struct xfs_inode        *dp = args->dp;
1746         struct xfs_trans        *tp = args->trans;
1747         struct xfs_buf          *fbp = NULL;
1748         xfs_dir2_db_t           firstfbno;
1749         xfs_dir2_db_t           lastfbno;
1750         xfs_dir2_db_t           ifbno = -1;
1751         xfs_dir2_db_t           dbno = -1;
1752         xfs_dir2_db_t           fbno;
1753         xfs_fileoff_t           fo;
1754         __be16                  *bests = NULL;
1755         int                     findex = 0;
1756         int                     error;
1757 
1758         /*
1759          * If we came in with a freespace block that means that lookup
1760          * found an entry with our hash value.  This is the freespace
1761          * block for that data entry.
1762          */
1763         if (fblk) {
1764                 fbp = fblk->bp;
1765                 free = fbp->b_addr;
1766                 findex = fblk->index;
1767                 if (findex >= 0) {
1768                         /* caller already found the freespace for us. */
1769                         bests = dp->d_ops->free_bests_p(free);
1770                         dp->d_ops->free_hdr_from_disk(&freehdr, free);
1771 
1772                         ASSERT(findex < freehdr.nvalid);
1773                         ASSERT(be16_to_cpu(bests[findex]) != NULLDATAOFF);
1774                         ASSERT(be16_to_cpu(bests[findex]) >= length);
1775                         dbno = freehdr.firstdb + findex;
1776                         goto found_block;
1777                 }
1778 
1779                 /*
1780                  * The data block looked at didn't have enough room.
1781                  * We'll start at the beginning of the freespace entries.
1782                  */
1783                 ifbno = fblk->blkno;
1784                 xfs_trans_brelse(tp, fbp);
1785                 fbp = NULL;
1786                 fblk->bp = NULL;
1787         }
1788 
1789         /*
1790          * If we don't have a data block yet, we're going to scan the freespace
1791          * data for a data block with enough free space in it.
1792          */
1793         error = xfs_bmap_last_offset(dp, &fo, XFS_DATA_FORK);
1794         if (error)
1795                 return error;
1796         lastfbno = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)fo);
1797         firstfbno = xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET);
1798 
1799         for (fbno = lastfbno - 1; fbno >= firstfbno; fbno--) {
1800                 /* If it's ifbno we already looked at it. */
1801                 if (fbno == ifbno)
1802                         continue;
1803 
1804                 /*
1805                  * Read the block.  There can be holes in the freespace blocks,
1806                  * so this might not succeed.  This should be really rare, so
1807                  * there's no reason to avoid it.
1808                  */
1809                 error = xfs_dir2_free_try_read(tp, dp,
1810                                 xfs_dir2_db_to_da(args->geo, fbno),
1811                                 &fbp);
1812                 if (error)
1813                         return error;
1814                 if (!fbp)
1815                         continue;
1816 
1817                 free = fbp->b_addr;
1818                 bests = dp->d_ops->free_bests_p(free);
1819                 dp->d_ops->free_hdr_from_disk(&freehdr, free);
1820 
1821                 /* Scan the free entry array for a large enough free space. */
1822                 for (findex = freehdr.nvalid - 1; findex >= 0; findex--) {
1823                         if (be16_to_cpu(bests[findex]) != NULLDATAOFF &&
1824                             be16_to_cpu(bests[findex]) >= length) {
1825                                 dbno = freehdr.firstdb + findex;
1826                                 goto found_block;
1827                         }
1828                 }
1829 
1830                 /* Didn't find free space, go on to next free block */
1831                 xfs_trans_brelse(tp, fbp);
1832         }
1833 
1834 found_block:
1835         *dbnop = dbno;
1836         *fbpp = fbp;
1837         *findexp = findex;
1838         return 0;
1839 }
1840 
1841 
1842 /*
1843  * Add the data entry for a node-format directory name addition.
1844  * The leaf entry is added in xfs_dir2_leafn_add.
1845  * We may enter with a freespace block that the lookup found.
1846  */
1847 static int
1848 xfs_dir2_node_addname_int(
1849         struct xfs_da_args      *args,          /* operation arguments */
1850         struct xfs_da_state_blk *fblk)          /* optional freespace block */
1851 {
1852         struct xfs_dir2_data_unused *dup;       /* data unused entry pointer */
1853         struct xfs_dir2_data_entry *dep;        /* data entry pointer */
1854         struct xfs_dir2_data_hdr *hdr;          /* data block header */
1855         struct xfs_dir2_data_free *bf;
1856         struct xfs_dir2_free    *free = NULL;   /* freespace block structure */
1857         struct xfs_trans        *tp = args->trans;
1858         struct xfs_inode        *dp = args->dp;
1859         struct xfs_buf          *dbp;           /* data block buffer */
1860         struct xfs_buf          *fbp;           /* freespace buffer */
1861         xfs_dir2_data_aoff_t    aoff;
1862         xfs_dir2_db_t           dbno;           /* data block number */
1863         int                     error;          /* error return value */
1864         int                     findex;         /* freespace entry index */
1865         int                     length;         /* length of the new entry */
1866         int                     logfree = 0;    /* need to log free entry */
1867         int                     needlog = 0;    /* need to log data header */
1868         int                     needscan = 0;   /* need to rescan data frees */
1869         __be16                  *tagp;          /* data entry tag pointer */
1870         __be16                  *bests;
1871 
1872         length = dp->d_ops->data_entsize(args->namelen);
1873         error = xfs_dir2_node_find_freeblk(args, fblk, &dbno, &fbp, &findex,
1874                                            length);
1875         if (error)
1876                 return error;
1877 
1878         /*
1879          * Now we know if we must allocate blocks, so if we are checking whether
1880          * we can insert without allocation then we can return now.
1881          */
1882         if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
1883                 if (dbno == -1)
1884                         return -ENOSPC;
1885                 return 0;
1886         }
1887 
1888         /*
1889          * If we don't have a data block, we need to allocate one and make
1890          * the freespace entries refer to it.
1891          */
1892         if (dbno == -1) {
1893                 /* we're going to have to log the free block index later */
1894                 logfree = 1;
1895                 error = xfs_dir2_node_add_datablk(args, fblk, &dbno, &dbp, &fbp,
1896                                                   &findex);
1897         } else {
1898                 /* Read the data block in. */
1899                 error = xfs_dir3_data_read(tp, dp,
1900                                            xfs_dir2_db_to_da(args->geo, dbno),
1901                                            -1, &dbp);
1902         }
1903         if (error)
1904                 return error;
1905 
1906         /* setup for data block up now */
1907         hdr = dbp->b_addr;
1908         bf = dp->d_ops->data_bestfree_p(hdr);
1909         ASSERT(be16_to_cpu(bf[0].length) >= length);
1910 
1911         /* Point to the existing unused space. */
1912         dup = (xfs_dir2_data_unused_t *)
1913               ((char *)hdr + be16_to_cpu(bf[0].offset));
1914 
1915         /* Mark the first part of the unused space, inuse for us. */
1916         aoff = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
1917         error = xfs_dir2_data_use_free(args, dbp, dup, aoff, length,
1918                         &needlog, &needscan);
1919         if (error) {
1920                 xfs_trans_brelse(tp, dbp);
1921                 return error;
1922         }
1923 
1924         /* Fill in the new entry and log it. */
1925         dep = (xfs_dir2_data_entry_t *)dup;
1926         dep->inumber = cpu_to_be64(args->inumber);
1927         dep->namelen = args->namelen;
1928         memcpy(dep->name, args->name, dep->namelen);
1929         dp->d_ops->data_put_ftype(dep, args->filetype);
1930         tagp = dp->d_ops->data_entry_tag_p(dep);
1931         *tagp = cpu_to_be16((char *)dep - (char *)hdr);
1932         xfs_dir2_data_log_entry(args, dbp, dep);
1933 
1934         /* Rescan the freespace and log the data block if needed. */
1935         if (needscan)
1936                 xfs_dir2_data_freescan(dp, hdr, &needlog);
1937         if (needlog)
1938                 xfs_dir2_data_log_header(args, dbp);
1939 
1940         /* If the freespace block entry is now wrong, update it. */
1941         free = fbp->b_addr;
1942         bests = dp->d_ops->free_bests_p(free);
1943         if (bests[findex] != bf[0].length) {
1944                 bests[findex] = bf[0].length;
1945                 logfree = 1;
1946         }
1947 
1948         /* Log the freespace entry if needed. */
1949         if (logfree)
1950                 xfs_dir2_free_log_bests(args, fbp, findex, findex);
1951 
1952         /* Return the data block and offset in args. */
1953         args->blkno = (xfs_dablk_t)dbno;
1954         args->index = be16_to_cpu(*tagp);
1955         return 0;
1956 }
1957 
1958 /*
1959  * Top-level node form directory addname routine.
1960  */
1961 int                                             /* error */
1962 xfs_dir2_node_addname(
1963         xfs_da_args_t           *args)          /* operation arguments */
1964 {
1965         xfs_da_state_blk_t      *blk;           /* leaf block for insert */
1966         int                     error;          /* error return value */
1967         int                     rval;           /* sub-return value */
1968         xfs_da_state_t          *state;         /* btree cursor */
1969 
1970         trace_xfs_dir2_node_addname(args);
1971 
1972         /*
1973          * Allocate and initialize the state (btree cursor).
1974          */
1975         state = xfs_da_state_alloc();
1976         state->args = args;
1977         state->mp = args->dp->i_mount;
1978         /*
1979          * Look up the name.  We're not supposed to find it, but
1980          * this gives us the insertion point.
1981          */
1982         error = xfs_da3_node_lookup_int(state, &rval);
1983         if (error)
1984                 rval = error;
1985         if (rval != -ENOENT) {
1986                 goto done;
1987         }
1988         /*
1989          * Add the data entry to a data block.
1990          * Extravalid is set to a freeblock found by lookup.
1991          */
1992         rval = xfs_dir2_node_addname_int(args,
1993                 state->extravalid ? &state->extrablk : NULL);
1994         if (rval) {
1995                 goto done;
1996         }
1997         blk = &state->path.blk[state->path.active - 1];
1998         ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
1999         /*
2000          * Add the new leaf entry.
2001          */
2002         rval = xfs_dir2_leafn_add(blk->bp, args, blk->index);
2003         if (rval == 0) {
2004                 /*
2005                  * It worked, fix the hash values up the btree.
2006                  */
2007                 if (!(args->op_flags & XFS_DA_OP_JUSTCHECK))
2008                         xfs_da3_fixhashpath(state, &state->path);
2009         } else {
2010                 /*
2011                  * It didn't work, we need to split the leaf block.
2012                  */
2013                 if (args->total == 0) {
2014                         ASSERT(rval == -ENOSPC);
2015                         goto done;
2016                 }
2017                 /*
2018                  * Split the leaf block and insert the new entry.
2019                  */
2020                 rval = xfs_da3_split(state);
2021         }
2022 done:
2023         xfs_da_state_free(state);
2024         return rval;
2025 }
2026 
2027 /*
2028  * Lookup an entry in a node-format directory.
2029  * All the real work happens in xfs_da3_node_lookup_int.
2030  * The only real output is the inode number of the entry.
2031  */
2032 int                                             /* error */
2033 xfs_dir2_node_lookup(
2034         xfs_da_args_t   *args)                  /* operation arguments */
2035 {
2036         int             error;                  /* error return value */
2037         int             i;                      /* btree level */
2038         int             rval;                   /* operation return value */
2039         xfs_da_state_t  *state;                 /* btree cursor */
2040 
2041         trace_xfs_dir2_node_lookup(args);
2042 
2043         /*
2044          * Allocate and initialize the btree cursor.
2045          */
2046         state = xfs_da_state_alloc();
2047         state->args = args;
2048         state->mp = args->dp->i_mount;
2049         /*
2050          * Fill in the path to the entry in the cursor.
2051          */
2052         error = xfs_da3_node_lookup_int(state, &rval);
2053         if (error)
2054                 rval = error;
2055         else if (rval == -ENOENT && args->cmpresult == XFS_CMP_CASE) {
2056                 /* If a CI match, dup the actual name and return -EEXIST */
2057                 xfs_dir2_data_entry_t   *dep;
2058 
2059                 dep = (xfs_dir2_data_entry_t *)
2060                         ((char *)state->extrablk.bp->b_addr +
2061                                                  state->extrablk.index);
2062                 rval = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
2063         }
2064         /*
2065          * Release the btree blocks and leaf block.
2066          */
2067         for (i = 0; i < state->path.active; i++) {
2068                 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
2069                 state->path.blk[i].bp = NULL;
2070         }
2071         /*
2072          * Release the data block if we have it.
2073          */
2074         if (state->extravalid && state->extrablk.bp) {
2075                 xfs_trans_brelse(args->trans, state->extrablk.bp);
2076                 state->extrablk.bp = NULL;
2077         }
2078         xfs_da_state_free(state);
2079         return rval;
2080 }
2081 
2082 /*
2083  * Remove an entry from a node-format directory.
2084  */
2085 int                                             /* error */
2086 xfs_dir2_node_removename(
2087         struct xfs_da_args      *args)          /* operation arguments */
2088 {
2089         struct xfs_da_state_blk *blk;           /* leaf block */
2090         int                     error;          /* error return value */
2091         int                     rval;           /* operation return value */
2092         struct xfs_da_state     *state;         /* btree cursor */
2093 
2094         trace_xfs_dir2_node_removename(args);
2095 
2096         /*
2097          * Allocate and initialize the btree cursor.
2098          */
2099         state = xfs_da_state_alloc();
2100         state->args = args;
2101         state->mp = args->dp->i_mount;
2102 
2103         /* Look up the entry we're deleting, set up the cursor. */
2104         error = xfs_da3_node_lookup_int(state, &rval);
2105         if (error)
2106                 goto out_free;
2107 
2108         /* Didn't find it, upper layer screwed up. */
2109         if (rval != -EEXIST) {
2110                 error = rval;
2111                 goto out_free;
2112         }
2113 
2114         blk = &state->path.blk[state->path.active - 1];
2115         ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
2116         ASSERT(state->extravalid);
2117         /*
2118          * Remove the leaf and data entries.
2119          * Extrablk refers to the data block.
2120          */
2121         error = xfs_dir2_leafn_remove(args, blk->bp, blk->index,
2122                 &state->extrablk, &rval);
2123         if (error)
2124                 goto out_free;
2125         /*
2126          * Fix the hash values up the btree.
2127          */
2128         xfs_da3_fixhashpath(state, &state->path);
2129         /*
2130          * If we need to join leaf blocks, do it.
2131          */
2132         if (rval && state->path.active > 1)
2133                 error = xfs_da3_join(state);
2134         /*
2135          * If no errors so far, try conversion to leaf format.
2136          */
2137         if (!error)
2138                 error = xfs_dir2_node_to_leaf(state);
2139 out_free:
2140         xfs_da_state_free(state);
2141         return error;
2142 }
2143 
2144 /*
2145  * Replace an entry's inode number in a node-format directory.
2146  */
2147 int                                             /* error */
2148 xfs_dir2_node_replace(
2149         xfs_da_args_t           *args)          /* operation arguments */
2150 {
2151         xfs_da_state_blk_t      *blk;           /* leaf block */
2152         xfs_dir2_data_hdr_t     *hdr;           /* data block header */
2153         xfs_dir2_data_entry_t   *dep;           /* data entry changed */
2154         int                     error;          /* error return value */
2155         int                     i;              /* btree level */
2156         xfs_ino_t               inum;           /* new inode number */
2157         int                     ftype;          /* new file type */
2158         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
2159         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry being changed */
2160         int                     rval;           /* internal return value */
2161         xfs_da_state_t          *state;         /* btree cursor */
2162 
2163         trace_xfs_dir2_node_replace(args);
2164 
2165         /*
2166          * Allocate and initialize the btree cursor.
2167          */
2168         state = xfs_da_state_alloc();
2169         state->args = args;
2170         state->mp = args->dp->i_mount;
2171 
2172         /*
2173          * We have to save new inode number and ftype since
2174          * xfs_da3_node_lookup_int() is going to overwrite them
2175          */
2176         inum = args->inumber;
2177         ftype = args->filetype;
2178 
2179         /*
2180          * Lookup the entry to change in the btree.
2181          */
2182         error = xfs_da3_node_lookup_int(state, &rval);
2183         if (error) {
2184                 rval = error;
2185         }
2186         /*
2187          * It should be found, since the vnodeops layer has looked it up
2188          * and locked it.  But paranoia is good.
2189          */
2190         if (rval == -EEXIST) {
2191                 struct xfs_dir2_leaf_entry *ents;
2192                 /*
2193                  * Find the leaf entry.
2194                  */
2195                 blk = &state->path.blk[state->path.active - 1];
2196                 ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
2197                 leaf = blk->bp->b_addr;
2198                 ents = args->dp->d_ops->leaf_ents_p(leaf);
2199                 lep = &ents[blk->index];
2200                 ASSERT(state->extravalid);
2201                 /*
2202                  * Point to the data entry.
2203                  */
2204                 hdr = state->extrablk.bp->b_addr;
2205                 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
2206                        hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC));
2207                 dep = (xfs_dir2_data_entry_t *)
2208                       ((char *)hdr +
2209                        xfs_dir2_dataptr_to_off(args->geo,
2210                                                be32_to_cpu(lep->address)));
2211                 ASSERT(inum != be64_to_cpu(dep->inumber));
2212                 /*
2213                  * Fill in the new inode number and log the entry.
2214                  */
2215                 dep->inumber = cpu_to_be64(inum);
2216                 args->dp->d_ops->data_put_ftype(dep, ftype);
2217                 xfs_dir2_data_log_entry(args, state->extrablk.bp, dep);
2218                 rval = 0;
2219         }
2220         /*
2221          * Didn't find it, and we're holding a data block.  Drop it.
2222          */
2223         else if (state->extravalid) {
2224                 xfs_trans_brelse(args->trans, state->extrablk.bp);
2225                 state->extrablk.bp = NULL;
2226         }
2227         /*
2228          * Release all the buffers in the cursor.
2229          */
2230         for (i = 0; i < state->path.active; i++) {
2231                 xfs_trans_brelse(args->trans, state->path.blk[i].bp);
2232                 state->path.blk[i].bp = NULL;
2233         }
2234         xfs_da_state_free(state);
2235         return rval;
2236 }
2237 
2238 /*
2239  * Trim off a trailing empty freespace block.
2240  * Return (in rvalp) 1 if we did it, 0 if not.
2241  */
2242 int                                             /* error */
2243 xfs_dir2_node_trim_free(
2244         xfs_da_args_t           *args,          /* operation arguments */
2245         xfs_fileoff_t           fo,             /* free block number */
2246         int                     *rvalp)         /* out: did something */
2247 {
2248         struct xfs_buf          *bp;            /* freespace buffer */
2249         xfs_inode_t             *dp;            /* incore directory inode */
2250         int                     error;          /* error return code */
2251         xfs_dir2_free_t         *free;          /* freespace structure */
2252         xfs_trans_t             *tp;            /* transaction pointer */
2253         struct xfs_dir3_icfree_hdr freehdr;
2254 
2255         dp = args->dp;
2256         tp = args->trans;
2257 
2258         *rvalp = 0;
2259 
2260         /*
2261          * Read the freespace block.
2262          */
2263         error = xfs_dir2_free_try_read(tp, dp, fo, &bp);
2264         if (error)
2265                 return error;
2266         /*
2267          * There can be holes in freespace.  If fo is a hole, there's
2268          * nothing to do.
2269          */
2270         if (!bp)
2271                 return 0;
2272         free = bp->b_addr;
2273         dp->d_ops->free_hdr_from_disk(&freehdr, free);
2274 
2275         /*
2276          * If there are used entries, there's nothing to do.
2277          */
2278         if (freehdr.nused > 0) {
2279                 xfs_trans_brelse(tp, bp);
2280                 return 0;
2281         }
2282         /*
2283          * Blow the block away.
2284          */
2285         error = xfs_dir2_shrink_inode(args,
2286                         xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)fo), bp);
2287         if (error) {
2288                 /*
2289                  * Can't fail with ENOSPC since that only happens with no
2290                  * space reservation, when breaking up an extent into two
2291                  * pieces.  This is the last block of an extent.
2292                  */
2293                 ASSERT(error != -ENOSPC);
2294                 xfs_trans_brelse(tp, bp);
2295                 return error;
2296         }
2297         /*
2298          * Return that we succeeded.
2299          */
2300         *rvalp = 1;
2301         return 0;
2302 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/xfs/libxfs/xfs_dir2_node.c

DEFINITIONS
