fs/xfs/libxfs/xfs_inode_fork.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6 #include <linux/log2.h>
   7
   8 #include "xfs.h"
   9 #include "xfs_fs.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_trans.h"
  16 #include "xfs_inode_item.h"
  17 #include "xfs_btree.h"
  18 #include "xfs_bmap_btree.h"
  19 #include "xfs_bmap.h"
  20 #include "xfs_error.h"
  21 #include "xfs_trace.h"
  22 #include "xfs_attr_sf.h"
  23 #include "xfs_da_format.h"
  24 #include "xfs_da_btree.h"
  25 #include "xfs_dir2_priv.h"
  26 #include "xfs_attr_leaf.h"
  27 #include "xfs_shared.h"
  28
  29 kmem_zone_t *xfs_ifork_zone;
  30
  31 STATIC int xfs_iformat_local(xfs_inode_t *, xfs_dinode_t *, int, int);
  32 STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
  33 STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);
  34
  35 /*
  36  * Copy inode type and data and attr format specific information from the
  37  * on-disk inode to the in-core inode and fork structures.  For fifos, devices,
  38  * and sockets this means set i_rdev to the proper value.  For files,
  39  * directories, and symlinks this means to bring in the in-line data or extent
  40  * pointers as well as the attribute fork.  For a fork in B-tree format, only
  41  * the root is immediately brought in-core.  The rest will be read in later when
  42  * first referenced (see xfs_iread_extents()).
  43  */
  44 int
  45 xfs_iformat_fork(
  46         struct xfs_inode        *ip,
  47         struct xfs_dinode       *dip)
  48 {
  49         struct inode            *inode = VFS_I(ip);
  50         struct xfs_attr_shortform *atp;
  51         int                     size;
  52         int                     error = 0;
  53         xfs_fsize_t             di_size;
  54
  55         switch (inode->i_mode & S_IFMT) {
  56         case S_IFIFO:
  57         case S_IFCHR:
  58         case S_IFBLK:
  59         case S_IFSOCK:
  60                 ip->i_d.di_size = 0;
  61                 inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
  62                 break;
  63
  64         case S_IFREG:
  65         case S_IFLNK:
  66         case S_IFDIR:
  67                 switch (dip->di_format) {
  68                 case XFS_DINODE_FMT_LOCAL:
  69                         di_size = be64_to_cpu(dip->di_size);
  70                         size = (int)di_size;
  71                         error = xfs_iformat_local(ip, dip, XFS_DATA_FORK, size);
  72                         break;
  73                 case XFS_DINODE_FMT_EXTENTS:
  74                         error = xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
  75                         break;
  76                 case XFS_DINODE_FMT_BTREE:
  77                         error = xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
  78                         break;
  79                 default:
  80                         return -EFSCORRUPTED;
  81                 }
  82                 break;
  83
  84         default:
  85                 return -EFSCORRUPTED;
  86         }
  87         if (error)
  88                 return error;
  89
  90         if (xfs_is_reflink_inode(ip)) {
  91                 ASSERT(ip->i_cowfp == NULL);
  92                 xfs_ifork_init_cow(ip);
  93         }
  94
  95         if (!XFS_DFORK_Q(dip))
  96                 return 0;
  97
  98         ASSERT(ip->i_afp == NULL);
  99         ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP | KM_NOFS);
 100
 101         switch (dip->di_aformat) {
 102         case XFS_DINODE_FMT_LOCAL:
 103                 atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
 104                 size = be16_to_cpu(atp->hdr.totsize);
 105
 106                 error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
 107                 break;
 108         case XFS_DINODE_FMT_EXTENTS:
 109                 error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
 110                 break;
 111         case XFS_DINODE_FMT_BTREE:
 112                 error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
 113                 break;
 114         default:
 115                 error = -EFSCORRUPTED;
 116                 break;
 117         }
 118         if (error) {
 119                 kmem_zone_free(xfs_ifork_zone, ip->i_afp);
 120                 ip->i_afp = NULL;
 121                 if (ip->i_cowfp)
 122                         kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
 123                 ip->i_cowfp = NULL;
 124                 xfs_idestroy_fork(ip, XFS_DATA_FORK);
 125         }
 126         return error;
 127 }
 128
 129 void
 130 xfs_init_local_fork(
 131         struct xfs_inode        *ip,
 132         int                     whichfork,
 133         const void              *data,
 134         int                     size)
 135 {
 136         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 137         int                     mem_size = size, real_size = 0;
 138         bool                    zero_terminate;
 139
 140         /*
 141          * If we are using the local fork to store a symlink body we need to
 142          * zero-terminate it so that we can pass it back to the VFS directly.
 143          * Overallocate the in-memory fork by one for that and add a zero
 144          * to terminate it below.
 145          */
 146         zero_terminate = S_ISLNK(VFS_I(ip)->i_mode);
 147         if (zero_terminate)
 148                 mem_size++;
 149
 150         if (size) {
 151                 real_size = roundup(mem_size, 4);
 152                 ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP | KM_NOFS);
 153                 memcpy(ifp->if_u1.if_data, data, size);
 154                 if (zero_terminate)
 155                         ifp->if_u1.if_data[size] = '\0';
 156         } else {
 157                 ifp->if_u1.if_data = NULL;
 158         }
 159
 160         ifp->if_bytes = size;
 161         ifp->if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
 162         ifp->if_flags |= XFS_IFINLINE;
 163 }
 164
 165 /*
 166  * The file is in-lined in the on-disk inode.
 167  */
 168 STATIC int
 169 xfs_iformat_local(
 170         xfs_inode_t     *ip,
 171         xfs_dinode_t    *dip,
 172         int             whichfork,
 173         int             size)
 174 {
 175         /*
 176          * If the size is unreasonable, then something
 177          * is wrong and we just bail out rather than crash in
 178          * kmem_alloc() or memcpy() below.
 179          */
 180         if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
 181                 xfs_warn(ip->i_mount,
 182         "corrupt inode %Lu (bad size %d for local fork, size = %d).",
 183                         (unsigned long long) ip->i_ino, size,
 184                         XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
 185                 xfs_inode_verifier_error(ip, -EFSCORRUPTED,
 186                                 "xfs_iformat_local", dip, sizeof(*dip),
 187                                 __this_address);
 188                 return -EFSCORRUPTED;
 189         }
 190
 191         xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
 192         return 0;
 193 }
 194
 195 /*
 196  * The file consists of a set of extents all of which fit into the on-disk
 197  * inode.
 198  */
 199 STATIC int
 200 xfs_iformat_extents(
 201         struct xfs_inode        *ip,
 202         struct xfs_dinode       *dip,
 203         int                     whichfork)
 204 {
 205         struct xfs_mount        *mp = ip->i_mount;
 206         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 207         int                     state = xfs_bmap_fork_to_state(whichfork);
 208         int                     nex = XFS_DFORK_NEXTENTS(dip, whichfork);
 209         int                     size = nex * sizeof(xfs_bmbt_rec_t);
 210         struct xfs_iext_cursor  icur;
 211         struct xfs_bmbt_rec     *dp;
 212         struct xfs_bmbt_irec    new;
 213         int                     i;
 214
 215         /*
 216          * If the number of extents is unreasonable, then something is wrong and
 217          * we just bail out rather than crash in kmem_alloc() or memcpy() below.
 218          */
 219         if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
 220                 xfs_warn(ip->i_mount, "corrupt inode %Lu ((a)extents = %d).",
 221                         (unsigned long long) ip->i_ino, nex);
 222                 xfs_inode_verifier_error(ip, -EFSCORRUPTED,
 223                                 "xfs_iformat_extents(1)", dip, sizeof(*dip),
 224                                 __this_address);
 225                 return -EFSCORRUPTED;
 226         }
 227
 228         ifp->if_bytes = 0;
 229         ifp->if_u1.if_root = NULL;
 230         ifp->if_height = 0;
 231         if (size) {
 232                 dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);
 233
 234                 xfs_iext_first(ifp, &icur);
 235                 for (i = 0; i < nex; i++, dp++) {
 236                         xfs_failaddr_t  fa;
 237
 238                         xfs_bmbt_disk_get_all(dp, &new);
 239                         fa = xfs_bmap_validate_extent(ip, whichfork, &new);
 240                         if (fa) {
 241                                 xfs_inode_verifier_error(ip, -EFSCORRUPTED,
 242                                                 "xfs_iformat_extents(2)",
 243                                                 dp, sizeof(*dp), fa);
 244                                 return -EFSCORRUPTED;
 245                         }
 246
 247                         xfs_iext_insert(ip, &icur, &new, state);
 248                         trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
 249                         xfs_iext_next(ifp, &icur);
 250                 }
 251         }
 252         ifp->if_flags |= XFS_IFEXTENTS;
 253         return 0;
 254 }
 255
 256 /*
 257  * The file has too many extents to fit into
 258  * the inode, so they are in B-tree format.
 259  * Allocate a buffer for the root of the B-tree
 260  * and copy the root into it.  The i_extents
 261  * field will remain NULL until all of the
 262  * extents are read in (when they are needed).
 263  */
 264 STATIC int
 265 xfs_iformat_btree(
 266         xfs_inode_t             *ip,
 267         xfs_dinode_t            *dip,
 268         int                     whichfork)
 269 {
 270         struct xfs_mount        *mp = ip->i_mount;
 271         xfs_bmdr_block_t        *dfp;
 272         struct xfs_ifork        *ifp;
 273         /* REFERENCED */
 274         int                     nrecs;
 275         int                     size;
 276         int                     level;
 277
 278         ifp = XFS_IFORK_PTR(ip, whichfork);
 279         dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork);
 280         size = XFS_BMAP_BROOT_SPACE(mp, dfp);
 281         nrecs = be16_to_cpu(dfp->bb_numrecs);
 282         level = be16_to_cpu(dfp->bb_level);
 283
 284         /*
 285          * blow out if -- fork has less extents than can fit in
 286          * fork (fork shouldn't be a btree format), root btree
 287          * block has more records than can fit into the fork,
 288          * or the number of extents is greater than the number of
 289          * blocks.
 290          */
 291         if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <=
 292                                         XFS_IFORK_MAXEXT(ip, whichfork) ||
 293                      nrecs == 0 ||
 294                      XFS_BMDR_SPACE_CALC(nrecs) >
 295                                         XFS_DFORK_SIZE(dip, mp, whichfork) ||
 296                      XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) ||
 297                      level == 0 || level > XFS_BTREE_MAXLEVELS) {
 298                 xfs_warn(mp, "corrupt inode %Lu (btree).",
 299                                         (unsigned long long) ip->i_ino);
 300                 xfs_inode_verifier_error(ip, -EFSCORRUPTED,
 301                                 "xfs_iformat_btree", dfp, size,
 302                                 __this_address);
 303                 return -EFSCORRUPTED;
 304         }
 305
 306         ifp->if_broot_bytes = size;
 307         ifp->if_broot = kmem_alloc(size, KM_SLEEP | KM_NOFS);
 308         ASSERT(ifp->if_broot != NULL);
 309         /*
 310          * Copy and convert from the on-disk structure
 311          * to the in-memory structure.
 312          */
 313         xfs_bmdr_to_bmbt(ip, dfp, XFS_DFORK_SIZE(dip, ip->i_mount, whichfork),
 314                          ifp->if_broot, size);
 315         ifp->if_flags &= ~XFS_IFEXTENTS;
 316         ifp->if_flags |= XFS_IFBROOT;
 317
 318         ifp->if_bytes = 0;
 319         ifp->if_u1.if_root = NULL;
 320         ifp->if_height = 0;
 321         return 0;
 322 }
 323
 324 /*
 325  * Reallocate the space for if_broot based on the number of records
 326  * being added or deleted as indicated in rec_diff.  Move the records
 327  * and pointers in if_broot to fit the new size.  When shrinking this
 328  * will eliminate holes between the records and pointers created by
 329  * the caller.  When growing this will create holes to be filled in
 330  * by the caller.
 331  *
 332  * The caller must not request to add more records than would fit in
 333  * the on-disk inode root.  If the if_broot is currently NULL, then
 334  * if we are adding records, one will be allocated.  The caller must also
 335  * not request that the number of records go below zero, although
 336  * it can go to zero.
 337  *
 338  * ip -- the inode whose if_broot area is changing
 339  * ext_diff -- the change in the number of records, positive or negative,
 340  *       requested for the if_broot array.
 341  */
 342 void
 343 xfs_iroot_realloc(
 344         xfs_inode_t             *ip,
 345         int                     rec_diff,
 346         int                     whichfork)
 347 {
 348         struct xfs_mount        *mp = ip->i_mount;
 349         int                     cur_max;
 350         struct xfs_ifork        *ifp;
 351         struct xfs_btree_block  *new_broot;
 352         int                     new_max;
 353         size_t                  new_size;
 354         char                    *np;
 355         char                    *op;
 356
 357         /*
 358          * Handle the degenerate case quietly.
 359          */
 360         if (rec_diff == 0) {
 361                 return;
 362         }
 363
 364         ifp = XFS_IFORK_PTR(ip, whichfork);
 365         if (rec_diff > 0) {
 366                 /*
 367                  * If there wasn't any memory allocated before, just
 368                  * allocate it now and get out.
 369                  */
 370                 if (ifp->if_broot_bytes == 0) {
 371                         new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, rec_diff);
 372                         ifp->if_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
 373                         ifp->if_broot_bytes = (int)new_size;
 374                         return;
 375                 }
 376
 377                 /*
 378                  * If there is already an existing if_broot, then we need
 379                  * to realloc() it and shift the pointers to their new
 380                  * location.  The records don't change location because
 381                  * they are kept butted up against the btree block header.
 382                  */
 383                 cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
 384                 new_max = cur_max + rec_diff;
 385                 new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
 386                 ifp->if_broot = kmem_realloc(ifp->if_broot, new_size,
 387                                 KM_SLEEP | KM_NOFS);
 388                 op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
 389                                                      ifp->if_broot_bytes);
 390                 np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
 391                                                      (int)new_size);
 392                 ifp->if_broot_bytes = (int)new_size;
 393                 ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
 394                         XFS_IFORK_SIZE(ip, whichfork));
 395                 memmove(np, op, cur_max * (uint)sizeof(xfs_fsblock_t));
 396                 return;
 397         }
 398
 399         /*
 400          * rec_diff is less than 0.  In this case, we are shrinking the
 401          * if_broot buffer.  It must already exist.  If we go to zero
 402          * records, just get rid of the root and clear the status bit.
 403          */
 404         ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
 405         cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
 406         new_max = cur_max + rec_diff;
 407         ASSERT(new_max >= 0);
 408         if (new_max > 0)
 409                 new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
 410         else
 411                 new_size = 0;
 412         if (new_size > 0) {
 413                 new_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
 414                 /*
 415                  * First copy over the btree block header.
 416                  */
 417                 memcpy(new_broot, ifp->if_broot,
 418                         XFS_BMBT_BLOCK_LEN(ip->i_mount));
 419         } else {
 420                 new_broot = NULL;
 421                 ifp->if_flags &= ~XFS_IFBROOT;
 422         }
 423
 424         /*
 425          * Only copy the records and pointers if there are any.
 426          */
 427         if (new_max > 0) {
 428                 /*
 429                  * First copy the records.
 430                  */
 431                 op = (char *)XFS_BMBT_REC_ADDR(mp, ifp->if_broot, 1);
 432                 np = (char *)XFS_BMBT_REC_ADDR(mp, new_broot, 1);
 433                 memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t));
 434
 435                 /*
 436                  * Then copy the pointers.
 437                  */
 438                 op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
 439                                                      ifp->if_broot_bytes);
 440                 np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, new_broot, 1,
 441                                                      (int)new_size);
 442                 memcpy(np, op, new_max * (uint)sizeof(xfs_fsblock_t));
 443         }
 444         kmem_free(ifp->if_broot);
 445         ifp->if_broot = new_broot;
 446         ifp->if_broot_bytes = (int)new_size;
 447         if (ifp->if_broot)
 448                 ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
 449                         XFS_IFORK_SIZE(ip, whichfork));
 450         return;
 451 }
 452
 453
 454 /*
 455  * This is called when the amount of space needed for if_data
 456  * is increased or decreased.  The change in size is indicated by
 457  * the number of bytes that need to be added or deleted in the
 458  * byte_diff parameter.
 459  *
 460  * If the amount of space needed has decreased below the size of the
 461  * inline buffer, then switch to using the inline buffer.  Otherwise,
 462  * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 463  * to what is needed.
 464  *
 465  * ip -- the inode whose if_data area is changing
 466  * byte_diff -- the change in the number of bytes, positive or negative,
 467  *       requested for the if_data array.
 468  */
 469 void
 470 xfs_idata_realloc(
 471         struct xfs_inode        *ip,
 472         int                     byte_diff,
 473         int                     whichfork)
 474 {
 475         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 476         int                     new_size = (int)ifp->if_bytes + byte_diff;
 477
 478         ASSERT(new_size >= 0);
 479         ASSERT(new_size <= XFS_IFORK_SIZE(ip, whichfork));
 480
 481         if (byte_diff == 0)
 482                 return;
 483
 484         if (new_size == 0) {
 485                 kmem_free(ifp->if_u1.if_data);
 486                 ifp->if_u1.if_data = NULL;
 487                 ifp->if_bytes = 0;
 488                 return;
 489         }
 490
 491         /*
 492          * For inline data, the underlying buffer must be a multiple of 4 bytes
 493          * in size so that it can be logged and stay on word boundaries.
 494          * We enforce that here.
 495          */
 496         ifp->if_u1.if_data = kmem_realloc(ifp->if_u1.if_data,
 497                         roundup(new_size, 4), KM_SLEEP | KM_NOFS);
 498         ifp->if_bytes = new_size;
 499 }
 500
 501 void
 502 xfs_idestroy_fork(
 503         xfs_inode_t     *ip,
 504         int             whichfork)
 505 {
 506         struct xfs_ifork        *ifp;
 507
 508         ifp = XFS_IFORK_PTR(ip, whichfork);
 509         if (ifp->if_broot != NULL) {
 510                 kmem_free(ifp->if_broot);
 511                 ifp->if_broot = NULL;
 512         }
 513
 514         /*
 515          * If the format is local, then we can't have an extents
 516          * array so just look for an inline data array.  If we're
 517          * not local then we may or may not have an extents list,
 518          * so check and free it up if we do.
 519          */
 520         if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
 521                 if (ifp->if_u1.if_data != NULL) {
 522                         kmem_free(ifp->if_u1.if_data);
 523                         ifp->if_u1.if_data = NULL;
 524                 }
 525         } else if ((ifp->if_flags & XFS_IFEXTENTS) && ifp->if_height) {
 526                 xfs_iext_destroy(ifp);
 527         }
 528
 529         if (whichfork == XFS_ATTR_FORK) {
 530                 kmem_zone_free(xfs_ifork_zone, ip->i_afp);
 531                 ip->i_afp = NULL;
 532         } else if (whichfork == XFS_COW_FORK) {
 533                 kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
 534                 ip->i_cowfp = NULL;
 535         }
 536 }
 537
 538 /*
 539  * Convert in-core extents to on-disk form
 540  *
 541  * In the case of the data fork, the in-core and on-disk fork sizes can be
 542  * different due to delayed allocation extents. We only copy on-disk extents
 543  * here, so callers must always use the physical fork size to determine the
 544  * size of the buffer passed to this routine.  We will return the size actually
 545  * used.
 546  */
 547 int
 548 xfs_iextents_copy(
 549         struct xfs_inode        *ip,
 550         struct xfs_bmbt_rec     *dp,
 551         int                     whichfork)
 552 {
 553         int                     state = xfs_bmap_fork_to_state(whichfork);
 554         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 555         struct xfs_iext_cursor  icur;
 556         struct xfs_bmbt_irec    rec;
 557         int                     copied = 0;
 558
 559         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
 560         ASSERT(ifp->if_bytes > 0);
 561
 562         for_each_xfs_iext(ifp, &icur, &rec) {
 563                 if (isnullstartblock(rec.br_startblock))
 564                         continue;
 565                 ASSERT(xfs_bmap_validate_extent(ip, whichfork, &rec) == NULL);
 566                 xfs_bmbt_disk_set_all(dp, &rec);
 567                 trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
 568                 copied += sizeof(struct xfs_bmbt_rec);
 569                 dp++;
 570         }
 571
 572         ASSERT(copied > 0);
 573         ASSERT(copied <= ifp->if_bytes);
 574         return copied;
 575 }
 576
 577 /*
 578  * Each of the following cases stores data into the same region
 579  * of the on-disk inode, so only one of them can be valid at
 580  * any given time. While it is possible to have conflicting formats
 581  * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
 582  * in EXTENTS format, this can only happen when the fork has
 583  * changed formats after being modified but before being flushed.
 584  * In these cases, the format always takes precedence, because the
 585  * format indicates the current state of the fork.
 586  */
 587 void
 588 xfs_iflush_fork(
 589         xfs_inode_t             *ip,
 590         xfs_dinode_t            *dip,
 591         xfs_inode_log_item_t    *iip,
 592         int                     whichfork)
 593 {
 594         char                    *cp;
 595         struct xfs_ifork        *ifp;
 596         xfs_mount_t             *mp;
 597         static const short      brootflag[2] =
 598                 { XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
 599         static const short      dataflag[2] =
 600                 { XFS_ILOG_DDATA, XFS_ILOG_ADATA };
 601         static const short      extflag[2] =
 602                 { XFS_ILOG_DEXT, XFS_ILOG_AEXT };
 603
 604         if (!iip)
 605                 return;
 606         ifp = XFS_IFORK_PTR(ip, whichfork);
 607         /*
 608          * This can happen if we gave up in iformat in an error path,
 609          * for the attribute fork.
 610          */
 611         if (!ifp) {
 612                 ASSERT(whichfork == XFS_ATTR_FORK);
 613                 return;
 614         }
 615         cp = XFS_DFORK_PTR(dip, whichfork);
 616         mp = ip->i_mount;
 617         switch (XFS_IFORK_FORMAT(ip, whichfork)) {
 618         case XFS_DINODE_FMT_LOCAL:
 619                 if ((iip->ili_fields & dataflag[whichfork]) &&
 620                     (ifp->if_bytes > 0)) {
 621                         ASSERT(ifp->if_u1.if_data != NULL);
 622                         ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
 623                         memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
 624                 }
 625                 break;
 626
 627         case XFS_DINODE_FMT_EXTENTS:
 628                 ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
 629                        !(iip->ili_fields & extflag[whichfork]));
 630                 if ((iip->ili_fields & extflag[whichfork]) &&
 631                     (ifp->if_bytes > 0)) {
 632                         ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
 633                         (void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
 634                                 whichfork);
 635                 }
 636                 break;
 637
 638         case XFS_DINODE_FMT_BTREE:
 639                 if ((iip->ili_fields & brootflag[whichfork]) &&
 640                     (ifp->if_broot_bytes > 0)) {
 641                         ASSERT(ifp->if_broot != NULL);
 642                         ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
 643                                 XFS_IFORK_SIZE(ip, whichfork));
 644                         xfs_bmbt_to_bmdr(mp, ifp->if_broot, ifp->if_broot_bytes,
 645                                 (xfs_bmdr_block_t *)cp,
 646                                 XFS_DFORK_SIZE(dip, mp, whichfork));
 647                 }
 648                 break;
 649
 650         case XFS_DINODE_FMT_DEV:
 651                 if (iip->ili_fields & XFS_ILOG_DEV) {
 652                         ASSERT(whichfork == XFS_DATA_FORK);
 653                         xfs_dinode_put_rdev(dip,
 654                                         linux_to_xfs_dev_t(VFS_I(ip)->i_rdev));
 655                 }
 656                 break;
 657
 658         default:
 659                 ASSERT(0);
 660                 break;
 661         }
 662 }
 663
 664 /* Convert bmap state flags to an inode fork. */
 665 struct xfs_ifork *
 666 xfs_iext_state_to_fork(
 667         struct xfs_inode        *ip,
 668         int                     state)
 669 {
 670         if (state & BMAP_COWFORK)
 671                 return ip->i_cowfp;
 672         else if (state & BMAP_ATTRFORK)
 673                 return ip->i_afp;
 674         return &ip->i_df;
 675 }
 676
 677 /*
 678  * Initialize an inode's copy-on-write fork.
 679  */
 680 void
 681 xfs_ifork_init_cow(
 682         struct xfs_inode        *ip)
 683 {
 684         if (ip->i_cowfp)
 685                 return;
 686
 687         ip->i_cowfp = kmem_zone_zalloc(xfs_ifork_zone,
 688                                        KM_SLEEP | KM_NOFS);
 689         ip->i_cowfp->if_flags = XFS_IFEXTENTS;
 690         ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
 691         ip->i_cnextents = 0;
 692 }
 693
 694 /* Default fork content verifiers. */
 695 struct xfs_ifork_ops xfs_default_ifork_ops = {
 696         .verify_attr    = xfs_attr_shortform_verify,
 697         .verify_dir     = xfs_dir2_sf_verify,
 698         .verify_symlink = xfs_symlink_shortform_verify,
 699 };
 700
 701 /* Verify the inline contents of the data fork of an inode. */
 702 xfs_failaddr_t
 703 xfs_ifork_verify_data(
 704         struct xfs_inode        *ip,
 705         struct xfs_ifork_ops    *ops)
 706 {
 707         /* Non-local data fork, we're done. */
 708         if (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
 709                 return NULL;
 710
 711         /* Check the inline data fork if there is one. */
 712         switch (VFS_I(ip)->i_mode & S_IFMT) {
 713         case S_IFDIR:
 714                 return ops->verify_dir(ip);
 715         case S_IFLNK:
 716                 return ops->verify_symlink(ip);
 717         default:
 718                 return NULL;
 719         }
 720 }
 721
 722 /* Verify the inline contents of the attr fork of an inode. */
 723 xfs_failaddr_t
 724 xfs_ifork_verify_attr(
 725         struct xfs_inode        *ip,
 726         struct xfs_ifork_ops    *ops)
 727 {
 728         /* There has to be an attr fork allocated if aformat is local. */
 729         if (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)
 730                 return NULL;
 731         if (!XFS_IFORK_PTR(ip, XFS_ATTR_FORK))
 732                 return __this_address;
 733         return ops->verify_attr(ip);
 734 }