The Design and Implementation of the FreeBSD Operating System, Second Edition
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sys/fs/ntfs/attrib.c

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    1 /**
    2  * attrib.c - NTFS attribute operations.  Part of the Linux-NTFS project.
    3  *
    4  * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
    5  * Copyright (c) 2002 Richard Russon
    6  *
    7  * This program/include file is free software; you can redistribute it and/or
    8  * modify it under the terms of the GNU General Public License as published
    9  * by the Free Software Foundation; either version 2 of the License, or
   10  * (at your option) any later version.
   11  *
   12  * This program/include file is distributed in the hope that it will be
   13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
   14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15  * GNU General Public License for more details.
   16  *
   17  * You should have received a copy of the GNU General Public License
   18  * along with this program (in the main directory of the Linux-NTFS
   19  * distribution in the file COPYING); if not, write to the Free Software
   20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   21  */
   22 
   23 #include <linux/buffer_head.h>
   24 #include <linux/sched.h>
   25 #include <linux/slab.h>
   26 #include <linux/swap.h>
   27 #include <linux/writeback.h>
   28 
   29 #include "attrib.h"
   30 #include "debug.h"
   31 #include "layout.h"
   32 #include "lcnalloc.h"
   33 #include "malloc.h"
   34 #include "mft.h"
   35 #include "ntfs.h"
   36 #include "types.h"
   37 
   38 /**
   39  * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode
   40  * @ni:         ntfs inode for which to map (part of) a runlist
   41  * @vcn:        map runlist part containing this vcn
   42  * @ctx:        active attribute search context if present or NULL if not
   43  *
   44  * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
   45  *
   46  * If @ctx is specified, it is an active search context of @ni and its base mft
   47  * record.  This is needed when ntfs_map_runlist_nolock() encounters unmapped
   48  * runlist fragments and allows their mapping.  If you do not have the mft
   49  * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock()
   50  * will perform the necessary mapping and unmapping.
   51  *
   52  * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and
   53  * restores it before returning.  Thus, @ctx will be left pointing to the same
   54  * attribute on return as on entry.  However, the actual pointers in @ctx may
   55  * point to different memory locations on return, so you must remember to reset
   56  * any cached pointers from the @ctx, i.e. after the call to
   57  * ntfs_map_runlist_nolock(), you will probably want to do:
   58  *      m = ctx->mrec;
   59  *      a = ctx->attr;
   60  * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
   61  * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
   62  *
   63  * Return 0 on success and -errno on error.  There is one special error code
   64  * which is not an error as such.  This is -ENOENT.  It means that @vcn is out
   65  * of bounds of the runlist.
   66  *
   67  * Note the runlist can be NULL after this function returns if @vcn is zero and
   68  * the attribute has zero allocated size, i.e. there simply is no runlist.
   69  *
   70  * WARNING: If @ctx is supplied, regardless of whether success or failure is
   71  *          returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
   72  *          is no longer valid, i.e. you need to either call
   73  *          ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
   74  *          In that case PTR_ERR(@ctx->mrec) will give you the error code for
   75  *          why the mapping of the old inode failed.
   76  *
   77  * Locking: - The runlist described by @ni must be locked for writing on entry
   78  *            and is locked on return.  Note the runlist will be modified.
   79  *          - If @ctx is NULL, the base mft record of @ni must not be mapped on
   80  *            entry and it will be left unmapped on return.
   81  *          - If @ctx is not NULL, the base mft record must be mapped on entry
   82  *            and it will be left mapped on return.
   83  */
   84 int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
   85 {
   86         VCN end_vcn;
   87         unsigned long flags;
   88         ntfs_inode *base_ni;
   89         MFT_RECORD *m;
   90         ATTR_RECORD *a;
   91         runlist_element *rl;
   92         struct page *put_this_page = NULL;
   93         int err = 0;
   94         bool ctx_is_temporary, ctx_needs_reset;
   95         ntfs_attr_search_ctx old_ctx = { NULL, };
   96 
   97         ntfs_debug("Mapping runlist part containing vcn 0x%llx.",
   98                         (unsigned long long)vcn);
   99         if (!NInoAttr(ni))
  100                 base_ni = ni;
  101         else
  102                 base_ni = ni->ext.base_ntfs_ino;
  103         if (!ctx) {
  104                 ctx_is_temporary = ctx_needs_reset = true;
  105                 m = map_mft_record(base_ni);
  106                 if (IS_ERR(m))
  107                         return PTR_ERR(m);
  108                 ctx = ntfs_attr_get_search_ctx(base_ni, m);
  109                 if (unlikely(!ctx)) {
  110                         err = -ENOMEM;
  111                         goto err_out;
  112                 }
  113         } else {
  114                 VCN allocated_size_vcn;
  115 
  116                 BUG_ON(IS_ERR(ctx->mrec));
  117                 a = ctx->attr;
  118                 BUG_ON(!a->non_resident);
  119                 ctx_is_temporary = false;
  120                 end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
  121                 read_lock_irqsave(&ni->size_lock, flags);
  122                 allocated_size_vcn = ni->allocated_size >>
  123                                 ni->vol->cluster_size_bits;
  124                 read_unlock_irqrestore(&ni->size_lock, flags);
  125                 if (!a->data.non_resident.lowest_vcn && end_vcn <= 0)
  126                         end_vcn = allocated_size_vcn - 1;
  127                 /*
  128                  * If we already have the attribute extent containing @vcn in
  129                  * @ctx, no need to look it up again.  We slightly cheat in
  130                  * that if vcn exceeds the allocated size, we will refuse to
  131                  * map the runlist below, so there is definitely no need to get
  132                  * the right attribute extent.
  133                  */
  134                 if (vcn >= allocated_size_vcn || (a->type == ni->type &&
  135                                 a->name_length == ni->name_len &&
  136                                 !memcmp((u8*)a + le16_to_cpu(a->name_offset),
  137                                 ni->name, ni->name_len) &&
  138                                 sle64_to_cpu(a->data.non_resident.lowest_vcn)
  139                                 <= vcn && end_vcn >= vcn))
  140                         ctx_needs_reset = false;
  141                 else {
  142                         /* Save the old search context. */
  143                         old_ctx = *ctx;
  144                         /*
  145                          * If the currently mapped (extent) inode is not the
  146                          * base inode we will unmap it when we reinitialize the
  147                          * search context which means we need to get a
  148                          * reference to the page containing the mapped mft
  149                          * record so we do not accidentally drop changes to the
  150                          * mft record when it has not been marked dirty yet.
  151                          */
  152                         if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino !=
  153                                         old_ctx.base_ntfs_ino) {
  154                                 put_this_page = old_ctx.ntfs_ino->page;
  155                                 page_cache_get(put_this_page);
  156                         }
  157                         /*
  158                          * Reinitialize the search context so we can lookup the
  159                          * needed attribute extent.
  160                          */
  161                         ntfs_attr_reinit_search_ctx(ctx);
  162                         ctx_needs_reset = true;
  163                 }
  164         }
  165         if (ctx_needs_reset) {
  166                 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
  167                                 CASE_SENSITIVE, vcn, NULL, 0, ctx);
  168                 if (unlikely(err)) {
  169                         if (err == -ENOENT)
  170                                 err = -EIO;
  171                         goto err_out;
  172                 }
  173                 BUG_ON(!ctx->attr->non_resident);
  174         }
  175         a = ctx->attr;
  176         /*
  177          * Only decompress the mapping pairs if @vcn is inside it.  Otherwise
  178          * we get into problems when we try to map an out of bounds vcn because
  179          * we then try to map the already mapped runlist fragment and
  180          * ntfs_mapping_pairs_decompress() fails.
  181          */
  182         end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
  183         if (unlikely(vcn && vcn >= end_vcn)) {
  184                 err = -ENOENT;
  185                 goto err_out;
  186         }
  187         rl = ntfs_mapping_pairs_decompress(ni->vol, a, ni->runlist.rl);
  188         if (IS_ERR(rl))
  189                 err = PTR_ERR(rl);
  190         else
  191                 ni->runlist.rl = rl;
  192 err_out:
  193         if (ctx_is_temporary) {
  194                 if (likely(ctx))
  195                         ntfs_attr_put_search_ctx(ctx);
  196                 unmap_mft_record(base_ni);
  197         } else if (ctx_needs_reset) {
  198                 /*
  199                  * If there is no attribute list, restoring the search context
  200                  * is accomplished simply by copying the saved context back over
  201                  * the caller supplied context.  If there is an attribute list,
  202                  * things are more complicated as we need to deal with mapping
  203                  * of mft records and resulting potential changes in pointers.
  204                  */
  205                 if (NInoAttrList(base_ni)) {
  206                         /*
  207                          * If the currently mapped (extent) inode is not the
  208                          * one we had before, we need to unmap it and map the
  209                          * old one.
  210                          */
  211                         if (ctx->ntfs_ino != old_ctx.ntfs_ino) {
  212                                 /*
  213                                  * If the currently mapped inode is not the
  214                                  * base inode, unmap it.
  215                                  */
  216                                 if (ctx->base_ntfs_ino && ctx->ntfs_ino !=
  217                                                 ctx->base_ntfs_ino) {
  218                                         unmap_extent_mft_record(ctx->ntfs_ino);
  219                                         ctx->mrec = ctx->base_mrec;
  220                                         BUG_ON(!ctx->mrec);
  221                                 }
  222                                 /*
  223                                  * If the old mapped inode is not the base
  224                                  * inode, map it.
  225                                  */
  226                                 if (old_ctx.base_ntfs_ino &&
  227                                                 old_ctx.ntfs_ino !=
  228                                                 old_ctx.base_ntfs_ino) {
  229 retry_map:
  230                                         ctx->mrec = map_mft_record(
  231                                                         old_ctx.ntfs_ino);
  232                                         /*
  233                                          * Something bad has happened.  If out
  234                                          * of memory retry till it succeeds.
  235                                          * Any other errors are fatal and we
  236                                          * return the error code in ctx->mrec.
  237                                          * Let the caller deal with it...  We
  238                                          * just need to fudge things so the
  239                                          * caller can reinit and/or put the
  240                                          * search context safely.
  241                                          */
  242                                         if (IS_ERR(ctx->mrec)) {
  243                                                 if (PTR_ERR(ctx->mrec) ==
  244                                                                 -ENOMEM) {
  245                                                         schedule();
  246                                                         goto retry_map;
  247                                                 } else
  248                                                         old_ctx.ntfs_ino =
  249                                                                 old_ctx.
  250                                                                 base_ntfs_ino;
  251                                         }
  252                                 }
  253                         }
  254                         /* Update the changed pointers in the saved context. */
  255                         if (ctx->mrec != old_ctx.mrec) {
  256                                 if (!IS_ERR(ctx->mrec))
  257                                         old_ctx.attr = (ATTR_RECORD*)(
  258                                                         (u8*)ctx->mrec +
  259                                                         ((u8*)old_ctx.attr -
  260                                                         (u8*)old_ctx.mrec));
  261                                 old_ctx.mrec = ctx->mrec;
  262                         }
  263                 }
  264                 /* Restore the search context to the saved one. */
  265                 *ctx = old_ctx;
  266                 /*
  267                  * We drop the reference on the page we took earlier.  In the
  268                  * case that IS_ERR(ctx->mrec) is true this means we might lose
  269                  * some changes to the mft record that had been made between
  270                  * the last time it was marked dirty/written out and now.  This
  271                  * at this stage is not a problem as the mapping error is fatal
  272                  * enough that the mft record cannot be written out anyway and
  273                  * the caller is very likely to shutdown the whole inode
  274                  * immediately and mark the volume dirty for chkdsk to pick up
  275                  * the pieces anyway.
  276                  */
  277                 if (put_this_page)
  278                         page_cache_release(put_this_page);
  279         }
  280         return err;
  281 }
  282 
  283 /**
  284  * ntfs_map_runlist - map (a part of) a runlist of an ntfs inode
  285  * @ni:         ntfs inode for which to map (part of) a runlist
  286  * @vcn:        map runlist part containing this vcn
  287  *
  288  * Map the part of a runlist containing the @vcn of the ntfs inode @ni.
  289  *
  290  * Return 0 on success and -errno on error.  There is one special error code
  291  * which is not an error as such.  This is -ENOENT.  It means that @vcn is out
  292  * of bounds of the runlist.
  293  *
  294  * Locking: - The runlist must be unlocked on entry and is unlocked on return.
  295  *          - This function takes the runlist lock for writing and may modify
  296  *            the runlist.
  297  */
  298 int ntfs_map_runlist(ntfs_inode *ni, VCN vcn)
  299 {
  300         int err = 0;
  301 
  302         down_write(&ni->runlist.lock);
  303         /* Make sure someone else didn't do the work while we were sleeping. */
  304         if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <=
  305                         LCN_RL_NOT_MAPPED))
  306                 err = ntfs_map_runlist_nolock(ni, vcn, NULL);
  307         up_write(&ni->runlist.lock);
  308         return err;
  309 }
  310 
  311 /**
  312  * ntfs_attr_vcn_to_lcn_nolock - convert a vcn into a lcn given an ntfs inode
  313  * @ni:                 ntfs inode of the attribute whose runlist to search
  314  * @vcn:                vcn to convert
  315  * @write_locked:       true if the runlist is locked for writing
  316  *
  317  * Find the virtual cluster number @vcn in the runlist of the ntfs attribute
  318  * described by the ntfs inode @ni and return the corresponding logical cluster
  319  * number (lcn).
  320  *
  321  * If the @vcn is not mapped yet, the attempt is made to map the attribute
  322  * extent containing the @vcn and the vcn to lcn conversion is retried.
  323  *
  324  * If @write_locked is true the caller has locked the runlist for writing and
  325  * if false for reading.
  326  *
  327  * Since lcns must be >= 0, we use negative return codes with special meaning:
  328  *
  329  * Return code  Meaning / Description
  330  * ==========================================
  331  *  LCN_HOLE    Hole / not allocated on disk.
  332  *  LCN_ENOENT  There is no such vcn in the runlist, i.e. @vcn is out of bounds.
  333  *  LCN_ENOMEM  Not enough memory to map runlist.
  334  *  LCN_EIO     Critical error (runlist/file is corrupt, i/o error, etc).
  335  *
  336  * Locking: - The runlist must be locked on entry and is left locked on return.
  337  *          - If @write_locked is 'false', i.e. the runlist is locked for reading,
  338  *            the lock may be dropped inside the function so you cannot rely on
  339  *            the runlist still being the same when this function returns.
  340  */
  341 LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
  342                 const bool write_locked)
  343 {
  344         LCN lcn;
  345         unsigned long flags;
  346         bool is_retry = false;
  347 
  348         BUG_ON(!ni);
  349         ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, %s_locked.",
  350                         ni->mft_no, (unsigned long long)vcn,
  351                         write_locked ? "write" : "read");
  352         BUG_ON(!NInoNonResident(ni));
  353         BUG_ON(vcn < 0);
  354         if (!ni->runlist.rl) {
  355                 read_lock_irqsave(&ni->size_lock, flags);
  356                 if (!ni->allocated_size) {
  357                         read_unlock_irqrestore(&ni->size_lock, flags);
  358                         return LCN_ENOENT;
  359                 }
  360                 read_unlock_irqrestore(&ni->size_lock, flags);
  361         }
  362 retry_remap:
  363         /* Convert vcn to lcn.  If that fails map the runlist and retry once. */
  364         lcn = ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn);
  365         if (likely(lcn >= LCN_HOLE)) {
  366                 ntfs_debug("Done, lcn 0x%llx.", (long long)lcn);
  367                 return lcn;
  368         }
  369         if (lcn != LCN_RL_NOT_MAPPED) {
  370                 if (lcn != LCN_ENOENT)
  371                         lcn = LCN_EIO;
  372         } else if (!is_retry) {
  373                 int err;
  374 
  375                 if (!write_locked) {
  376                         up_read(&ni->runlist.lock);
  377                         down_write(&ni->runlist.lock);
  378                         if (unlikely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) !=
  379                                         LCN_RL_NOT_MAPPED)) {
  380                                 up_write(&ni->runlist.lock);
  381                                 down_read(&ni->runlist.lock);
  382                                 goto retry_remap;
  383                         }
  384                 }
  385                 err = ntfs_map_runlist_nolock(ni, vcn, NULL);
  386                 if (!write_locked) {
  387                         up_write(&ni->runlist.lock);
  388                         down_read(&ni->runlist.lock);
  389                 }
  390                 if (likely(!err)) {
  391                         is_retry = true;
  392                         goto retry_remap;
  393                 }
  394                 if (err == -ENOENT)
  395                         lcn = LCN_ENOENT;
  396                 else if (err == -ENOMEM)
  397                         lcn = LCN_ENOMEM;
  398                 else
  399                         lcn = LCN_EIO;
  400         }
  401         if (lcn != LCN_ENOENT)
  402                 ntfs_error(ni->vol->sb, "Failed with error code %lli.",
  403                                 (long long)lcn);
  404         return lcn;
  405 }
  406 
  407 /**
  408  * ntfs_attr_find_vcn_nolock - find a vcn in the runlist of an ntfs inode
  409  * @ni:         ntfs inode describing the runlist to search
  410  * @vcn:        vcn to find
  411  * @ctx:        active attribute search context if present or NULL if not
  412  *
  413  * Find the virtual cluster number @vcn in the runlist described by the ntfs
  414  * inode @ni and return the address of the runlist element containing the @vcn.
  415  *
  416  * If the @vcn is not mapped yet, the attempt is made to map the attribute
  417  * extent containing the @vcn and the vcn to lcn conversion is retried.
  418  *
  419  * If @ctx is specified, it is an active search context of @ni and its base mft
  420  * record.  This is needed when ntfs_attr_find_vcn_nolock() encounters unmapped
  421  * runlist fragments and allows their mapping.  If you do not have the mft
  422  * record mapped, you can specify @ctx as NULL and ntfs_attr_find_vcn_nolock()
  423  * will perform the necessary mapping and unmapping.
  424  *
  425  * Note, ntfs_attr_find_vcn_nolock() saves the state of @ctx on entry and
  426  * restores it before returning.  Thus, @ctx will be left pointing to the same
  427  * attribute on return as on entry.  However, the actual pointers in @ctx may
  428  * point to different memory locations on return, so you must remember to reset
  429  * any cached pointers from the @ctx, i.e. after the call to
  430  * ntfs_attr_find_vcn_nolock(), you will probably want to do:
  431  *      m = ctx->mrec;
  432  *      a = ctx->attr;
  433  * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
  434  * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
  435  * Note you need to distinguish between the lcn of the returned runlist element
  436  * being >= 0 and LCN_HOLE.  In the later case you have to return zeroes on
  437  * read and allocate clusters on write.
  438  *
  439  * Return the runlist element containing the @vcn on success and
  440  * ERR_PTR(-errno) on error.  You need to test the return value with IS_ERR()
  441  * to decide if the return is success or failure and PTR_ERR() to get to the
  442  * error code if IS_ERR() is true.
  443  *
  444  * The possible error return codes are:
  445  *      -ENOENT - No such vcn in the runlist, i.e. @vcn is out of bounds.
  446  *      -ENOMEM - Not enough memory to map runlist.
  447  *      -EIO    - Critical error (runlist/file is corrupt, i/o error, etc).
  448  *
  449  * WARNING: If @ctx is supplied, regardless of whether success or failure is
  450  *          returned, you need to check IS_ERR(@ctx->mrec) and if 'true' the @ctx
  451  *          is no longer valid, i.e. you need to either call
  452  *          ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
  453  *          In that case PTR_ERR(@ctx->mrec) will give you the error code for
  454  *          why the mapping of the old inode failed.
  455  *
  456  * Locking: - The runlist described by @ni must be locked for writing on entry
  457  *            and is locked on return.  Note the runlist may be modified when
  458  *            needed runlist fragments need to be mapped.
  459  *          - If @ctx is NULL, the base mft record of @ni must not be mapped on
  460  *            entry and it will be left unmapped on return.
  461  *          - If @ctx is not NULL, the base mft record must be mapped on entry
  462  *            and it will be left mapped on return.
  463  */
  464 runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni, const VCN vcn,
  465                 ntfs_attr_search_ctx *ctx)
  466 {
  467         unsigned long flags;
  468         runlist_element *rl;
  469         int err = 0;
  470         bool is_retry = false;
  471 
  472         BUG_ON(!ni);
  473         ntfs_debug("Entering for i_ino 0x%lx, vcn 0x%llx, with%s ctx.",
  474                         ni->mft_no, (unsigned long long)vcn, ctx ? "" : "out");
  475         BUG_ON(!NInoNonResident(ni));
  476         BUG_ON(vcn < 0);
  477         if (!ni->runlist.rl) {
  478                 read_lock_irqsave(&ni->size_lock, flags);
  479                 if (!ni->allocated_size) {
  480                         read_unlock_irqrestore(&ni->size_lock, flags);
  481                         return ERR_PTR(-ENOENT);
  482                 }
  483                 read_unlock_irqrestore(&ni->size_lock, flags);
  484         }
  485 retry_remap:
  486         rl = ni->runlist.rl;
  487         if (likely(rl && vcn >= rl[0].vcn)) {
  488                 while (likely(rl->length)) {
  489                         if (unlikely(vcn < rl[1].vcn)) {
  490                                 if (likely(rl->lcn >= LCN_HOLE)) {
  491                                         ntfs_debug("Done.");
  492                                         return rl;
  493                                 }
  494                                 break;
  495                         }
  496                         rl++;
  497                 }
  498                 if (likely(rl->lcn != LCN_RL_NOT_MAPPED)) {
  499                         if (likely(rl->lcn == LCN_ENOENT))
  500                                 err = -ENOENT;
  501                         else
  502                                 err = -EIO;
  503                 }
  504         }
  505         if (!err && !is_retry) {
  506                 /*
  507                  * If the search context is invalid we cannot map the unmapped
  508                  * region.
  509                  */
  510                 if (IS_ERR(ctx->mrec))
  511                         err = PTR_ERR(ctx->mrec);
  512                 else {
  513                         /*
  514                          * The @vcn is in an unmapped region, map the runlist
  515                          * and retry.
  516                          */
  517                         err = ntfs_map_runlist_nolock(ni, vcn, ctx);
  518                         if (likely(!err)) {
  519                                 is_retry = true;
  520                                 goto retry_remap;
  521                         }
  522                 }
  523                 if (err == -EINVAL)
  524                         err = -EIO;
  525         } else if (!err)
  526                 err = -EIO;
  527         if (err != -ENOENT)
  528                 ntfs_error(ni->vol->sb, "Failed with error code %i.", err);
  529         return ERR_PTR(err);
  530 }
  531 
  532 /**
  533  * ntfs_attr_find - find (next) attribute in mft record
  534  * @type:       attribute type to find
  535  * @name:       attribute name to find (optional, i.e. NULL means don't care)
  536  * @name_len:   attribute name length (only needed if @name present)
  537  * @ic:         IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
  538  * @val:        attribute value to find (optional, resident attributes only)
  539  * @val_len:    attribute value length
  540  * @ctx:        search context with mft record and attribute to search from
  541  *
  542  * You should not need to call this function directly.  Use ntfs_attr_lookup()
  543  * instead.
  544  *
  545  * ntfs_attr_find() takes a search context @ctx as parameter and searches the
  546  * mft record specified by @ctx->mrec, beginning at @ctx->attr, for an
  547  * attribute of @type, optionally @name and @val.
  548  *
  549  * If the attribute is found, ntfs_attr_find() returns 0 and @ctx->attr will
  550  * point to the found attribute.
  551  *
  552  * If the attribute is not found, ntfs_attr_find() returns -ENOENT and
  553  * @ctx->attr will point to the attribute before which the attribute being
  554  * searched for would need to be inserted if such an action were to be desired.
  555  *
  556  * On actual error, ntfs_attr_find() returns -EIO.  In this case @ctx->attr is
  557  * undefined and in particular do not rely on it not changing.
  558  *
  559  * If @ctx->is_first is 'true', the search begins with @ctx->attr itself.  If it
  560  * is 'false', the search begins after @ctx->attr.
  561  *
  562  * If @ic is IGNORE_CASE, the @name comparisson is not case sensitive and
  563  * @ctx->ntfs_ino must be set to the ntfs inode to which the mft record
  564  * @ctx->mrec belongs.  This is so we can get at the ntfs volume and hence at
  565  * the upcase table.  If @ic is CASE_SENSITIVE, the comparison is case
  566  * sensitive.  When @name is present, @name_len is the @name length in Unicode
  567  * characters.
  568  *
  569  * If @name is not present (NULL), we assume that the unnamed attribute is
  570  * being searched for.
  571  *
  572  * Finally, the resident attribute value @val is looked for, if present.  If
  573  * @val is not present (NULL), @val_len is ignored.
  574  *
  575  * ntfs_attr_find() only searches the specified mft record and it ignores the
  576  * presence of an attribute list attribute (unless it is the one being searched
  577  * for, obviously).  If you need to take attribute lists into consideration,
  578  * use ntfs_attr_lookup() instead (see below).  This also means that you cannot
  579  * use ntfs_attr_find() to search for extent records of non-resident
  580  * attributes, as extents with lowest_vcn != 0 are usually described by the
  581  * attribute list attribute only. - Note that it is possible that the first
  582  * extent is only in the attribute list while the last extent is in the base
  583  * mft record, so do not rely on being able to find the first extent in the
  584  * base mft record.
  585  *
  586  * Warning: Never use @val when looking for attribute types which can be
  587  *          non-resident as this most likely will result in a crash!
  588  */
  589 static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name,
  590                 const u32 name_len, const IGNORE_CASE_BOOL ic,
  591                 const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
  592 {
  593         ATTR_RECORD *a;
  594         ntfs_volume *vol = ctx->ntfs_ino->vol;
  595         ntfschar *upcase = vol->upcase;
  596         u32 upcase_len = vol->upcase_len;
  597 
  598         /*
  599          * Iterate over attributes in mft record starting at @ctx->attr, or the
  600          * attribute following that, if @ctx->is_first is 'true'.
  601          */
  602         if (ctx->is_first) {
  603                 a = ctx->attr;
  604                 ctx->is_first = false;
  605         } else
  606                 a = (ATTR_RECORD*)((u8*)ctx->attr +
  607                                 le32_to_cpu(ctx->attr->length));
  608         for (;; a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))) {
  609                 if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
  610                                 le32_to_cpu(ctx->mrec->bytes_allocated))
  611                         break;
  612                 ctx->attr = a;
  613                 if (unlikely(le32_to_cpu(a->type) > le32_to_cpu(type) ||
  614                                 a->type == AT_END))
  615                         return -ENOENT;
  616                 if (unlikely(!a->length))
  617                         break;
  618                 if (a->type != type)
  619                         continue;
  620                 /*
  621                  * If @name is present, compare the two names.  If @name is
  622                  * missing, assume we want an unnamed attribute.
  623                  */
  624                 if (!name) {
  625                         /* The search failed if the found attribute is named. */
  626                         if (a->name_length)
  627                                 return -ENOENT;
  628                 } else if (!ntfs_are_names_equal(name, name_len,
  629                             (ntfschar*)((u8*)a + le16_to_cpu(a->name_offset)),
  630                             a->name_length, ic, upcase, upcase_len)) {
  631                         register int rc;
  632 
  633                         rc = ntfs_collate_names(name, name_len,
  634                                         (ntfschar*)((u8*)a +
  635                                         le16_to_cpu(a->name_offset)),
  636                                         a->name_length, 1, IGNORE_CASE,
  637                                         upcase, upcase_len);
  638                         /*
  639                          * If @name collates before a->name, there is no
  640                          * matching attribute.
  641                          */
  642                         if (rc == -1)
  643                                 return -ENOENT;
  644                         /* If the strings are not equal, continue search. */
  645                         if (rc)
  646                                 continue;
  647                         rc = ntfs_collate_names(name, name_len,
  648                                         (ntfschar*)((u8*)a +
  649                                         le16_to_cpu(a->name_offset)),
  650                                         a->name_length, 1, CASE_SENSITIVE,
  651                                         upcase, upcase_len);
  652                         if (rc == -1)
  653                                 return -ENOENT;
  654                         if (rc)
  655                                 continue;
  656                 }
  657                 /*
  658                  * The names match or @name not present and attribute is
  659                  * unnamed.  If no @val specified, we have found the attribute
  660                  * and are done.
  661                  */
  662                 if (!val)
  663                         return 0;
  664                 /* @val is present; compare values. */
  665                 else {
  666                         register int rc;
  667 
  668                         rc = memcmp(val, (u8*)a + le16_to_cpu(
  669                                         a->data.resident.value_offset),
  670                                         min_t(u32, val_len, le32_to_cpu(
  671                                         a->data.resident.value_length)));
  672                         /*
  673                          * If @val collates before the current attribute's
  674                          * value, there is no matching attribute.
  675                          */
  676                         if (!rc) {
  677                                 register u32 avl;
  678 
  679                                 avl = le32_to_cpu(
  680                                                 a->data.resident.value_length);
  681                                 if (val_len == avl)
  682                                         return 0;
  683                                 if (val_len < avl)
  684                                         return -ENOENT;
  685                         } else if (rc < 0)
  686                                 return -ENOENT;
  687                 }
  688         }
  689         ntfs_error(vol->sb, "Inode is corrupt.  Run chkdsk.");
  690         NVolSetErrors(vol);
  691         return -EIO;
  692 }
  693 
  694 /**
  695  * load_attribute_list - load an attribute list into memory
  696  * @vol:                ntfs volume from which to read
  697  * @runlist:            runlist of the attribute list
  698  * @al_start:           destination buffer
  699  * @size:               size of the destination buffer in bytes
  700  * @initialized_size:   initialized size of the attribute list
  701  *
  702  * Walk the runlist @runlist and load all clusters from it copying them into
  703  * the linear buffer @al. The maximum number of bytes copied to @al is @size
  704  * bytes. Note, @size does not need to be a multiple of the cluster size. If
  705  * @initialized_size is less than @size, the region in @al between
  706  * @initialized_size and @size will be zeroed and not read from disk.
  707  *
  708  * Return 0 on success or -errno on error.
  709  */
  710 int load_attribute_list(ntfs_volume *vol, runlist *runlist, u8 *al_start,
  711                 const s64 size, const s64 initialized_size)
  712 {
  713         LCN lcn;
  714         u8 *al = al_start;
  715         u8 *al_end = al + initialized_size;
  716         runlist_element *rl;
  717         struct buffer_head *bh;
  718         struct super_block *sb;
  719         unsigned long block_size;
  720         unsigned long block, max_block;
  721         int err = 0;
  722         unsigned char block_size_bits;
  723 
  724         ntfs_debug("Entering.");
  725         if (!vol || !runlist || !al || size <= 0 || initialized_size < 0 ||
  726                         initialized_size > size)
  727                 return -EINVAL;
  728         if (!initialized_size) {
  729                 memset(al, 0, size);
  730                 return 0;
  731         }
  732         sb = vol->sb;
  733         block_size = sb->s_blocksize;
  734         block_size_bits = sb->s_blocksize_bits;
  735         down_read(&runlist->lock);
  736         rl = runlist->rl;
  737         if (!rl) {
  738                 ntfs_error(sb, "Cannot read attribute list since runlist is "
  739                                 "missing.");
  740                 goto err_out;   
  741         }
  742         /* Read all clusters specified by the runlist one run at a time. */
  743         while (rl->length) {
  744                 lcn = ntfs_rl_vcn_to_lcn(rl, rl->vcn);
  745                 ntfs_debug("Reading vcn = 0x%llx, lcn = 0x%llx.",
  746                                 (unsigned long long)rl->vcn,
  747                                 (unsigned long long)lcn);
  748                 /* The attribute list cannot be sparse. */
  749                 if (lcn < 0) {
  750                         ntfs_error(sb, "ntfs_rl_vcn_to_lcn() failed.  Cannot "
  751                                         "read attribute list.");
  752                         goto err_out;
  753                 }
  754                 block = lcn << vol->cluster_size_bits >> block_size_bits;
  755                 /* Read the run from device in chunks of block_size bytes. */
  756                 max_block = block + (rl->length << vol->cluster_size_bits >>
  757                                 block_size_bits);
  758                 ntfs_debug("max_block = 0x%lx.", max_block);
  759                 do {
  760                         ntfs_debug("Reading block = 0x%lx.", block);
  761                         bh = sb_bread(sb, block);
  762                         if (!bh) {
  763                                 ntfs_error(sb, "sb_bread() failed. Cannot "
  764                                                 "read attribute list.");
  765                                 goto err_out;
  766                         }
  767                         if (al + block_size >= al_end)
  768                                 goto do_final;
  769                         memcpy(al, bh->b_data, block_size);
  770                         brelse(bh);
  771                         al += block_size;
  772                 } while (++block < max_block);
  773                 rl++;
  774         }
  775         if (initialized_size < size) {
  776 initialize:
  777                 memset(al_start + initialized_size, 0, size - initialized_size);
  778         }
  779 done:
  780         up_read(&runlist->lock);
  781         return err;
  782 do_final:
  783         if (al < al_end) {
  784                 /*
  785                  * Partial block.
  786                  *
  787                  * Note: The attribute list can be smaller than its allocation
  788                  * by multiple clusters.  This has been encountered by at least
  789                  * two people running Windows XP, thus we cannot do any
  790                  * truncation sanity checking here. (AIA)
  791                  */
  792                 memcpy(al, bh->b_data, al_end - al);
  793                 brelse(bh);
  794                 if (initialized_size < size)
  795                         goto initialize;
  796                 goto done;
  797         }
  798         brelse(bh);
  799         /* Real overflow! */
  800         ntfs_error(sb, "Attribute list buffer overflow. Read attribute list "
  801                         "is truncated.");
  802 err_out:
  803         err = -EIO;
  804         goto done;
  805 }
  806 
  807 /**
  808  * ntfs_external_attr_find - find an attribute in the attribute list of an inode
  809  * @type:       attribute type to find
  810  * @name:       attribute name to find (optional, i.e. NULL means don't care)
  811  * @name_len:   attribute name length (only needed if @name present)
  812  * @ic:         IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
  813  * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
  814  * @val:        attribute value to find (optional, resident attributes only)
  815  * @val_len:    attribute value length
  816  * @ctx:        search context with mft record and attribute to search from
  817  *
  818  * You should not need to call this function directly.  Use ntfs_attr_lookup()
  819  * instead.
  820  *
  821  * Find an attribute by searching the attribute list for the corresponding
  822  * attribute list entry.  Having found the entry, map the mft record if the
  823  * attribute is in a different mft record/inode, ntfs_attr_find() the attribute
  824  * in there and return it.
  825  *
  826  * On first search @ctx->ntfs_ino must be the base mft record and @ctx must
  827  * have been obtained from a call to ntfs_attr_get_search_ctx().  On subsequent
  828  * calls @ctx->ntfs_ino can be any extent inode, too (@ctx->base_ntfs_ino is
  829  * then the base inode).
  830  *
  831  * After finishing with the attribute/mft record you need to call
  832  * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
  833  * mapped inodes, etc).
  834  *
  835  * If the attribute is found, ntfs_external_attr_find() returns 0 and
  836  * @ctx->attr will point to the found attribute.  @ctx->mrec will point to the
  837  * mft record in which @ctx->attr is located and @ctx->al_entry will point to
  838  * the attribute list entry for the attribute.
  839  *
  840  * If the attribute is not found, ntfs_external_attr_find() returns -ENOENT and
  841  * @ctx->attr will point to the attribute in the base mft record before which
  842  * the attribute being searched for would need to be inserted if such an action
  843  * were to be desired.  @ctx->mrec will point to the mft record in which
  844  * @ctx->attr is located and @ctx->al_entry will point to the attribute list
  845  * entry of the attribute before which the attribute being searched for would
  846  * need to be inserted if such an action were to be desired.
  847  *
  848  * Thus to insert the not found attribute, one wants to add the attribute to
  849  * @ctx->mrec (the base mft record) and if there is not enough space, the
  850  * attribute should be placed in a newly allocated extent mft record.  The
  851  * attribute list entry for the inserted attribute should be inserted in the
  852  * attribute list attribute at @ctx->al_entry.
  853  *
  854  * On actual error, ntfs_external_attr_find() returns -EIO.  In this case
  855  * @ctx->attr is undefined and in particular do not rely on it not changing.
  856  */
  857 static int ntfs_external_attr_find(const ATTR_TYPE type,
  858                 const ntfschar *name, const u32 name_len,
  859                 const IGNORE_CASE_BOOL ic, const VCN lowest_vcn,
  860                 const u8 *val, const u32 val_len, ntfs_attr_search_ctx *ctx)
  861 {
  862         ntfs_inode *base_ni, *ni;
  863         ntfs_volume *vol;
  864         ATTR_LIST_ENTRY *al_entry, *next_al_entry;
  865         u8 *al_start, *al_end;
  866         ATTR_RECORD *a;
  867         ntfschar *al_name;
  868         u32 al_name_len;
  869         int err = 0;
  870         static const char *es = " Unmount and run chkdsk.";
  871 
  872         ni = ctx->ntfs_ino;
  873         base_ni = ctx->base_ntfs_ino;
  874         ntfs_debug("Entering for inode 0x%lx, type 0x%x.", ni->mft_no, type);
  875         if (!base_ni) {
  876                 /* First call happens with the base mft record. */
  877                 base_ni = ctx->base_ntfs_ino = ctx->ntfs_ino;
  878                 ctx->base_mrec = ctx->mrec;
  879         }
  880         if (ni == base_ni)
  881                 ctx->base_attr = ctx->attr;
  882         if (type == AT_END)
  883                 goto not_found;
  884         vol = base_ni->vol;
  885         al_start = base_ni->attr_list;
  886         al_end = al_start + base_ni->attr_list_size;
  887         if (!ctx->al_entry)
  888                 ctx->al_entry = (ATTR_LIST_ENTRY*)al_start;
  889         /*
  890          * Iterate over entries in attribute list starting at @ctx->al_entry,
  891          * or the entry following that, if @ctx->is_first is 'true'.
  892          */
  893         if (ctx->is_first) {
  894                 al_entry = ctx->al_entry;
  895                 ctx->is_first = false;
  896         } else
  897                 al_entry = (ATTR_LIST_ENTRY*)((u8*)ctx->al_entry +
  898                                 le16_to_cpu(ctx->al_entry->length));
  899         for (;; al_entry = next_al_entry) {
  900                 /* Out of bounds check. */
  901                 if ((u8*)al_entry < base_ni->attr_list ||
  902                                 (u8*)al_entry > al_end)
  903                         break;  /* Inode is corrupt. */
  904                 ctx->al_entry = al_entry;
  905                 /* Catch the end of the attribute list. */
  906                 if ((u8*)al_entry == al_end)
  907                         goto not_found;
  908                 if (!al_entry->length)
  909                         break;
  910                 if ((u8*)al_entry + 6 > al_end || (u8*)al_entry +
  911                                 le16_to_cpu(al_entry->length) > al_end)
  912                         break;
  913                 next_al_entry = (ATTR_LIST_ENTRY*)((u8*)al_entry +
  914                                 le16_to_cpu(al_entry->length));
  915                 if (le32_to_cpu(al_entry->type) > le32_to_cpu(type))
  916                         goto not_found;
  917                 if (type != al_entry->type)
  918                         continue;
  919                 /*
  920                  * If @name is present, compare the two names.  If @name is
  921                  * missing, assume we want an unnamed attribute.
  922                  */
  923                 al_name_len = al_entry->name_length;
  924                 al_name = (ntfschar*)((u8*)al_entry + al_entry->name_offset);
  925                 if (!name) {
  926                         if (al_name_len)
  927                                 goto not_found;
  928                 } else if (!ntfs_are_names_equal(al_name, al_name_len, name,
  929                                 name_len, ic, vol->upcase, vol->upcase_len)) {
  930                         register int rc;
  931 
  932                         rc = ntfs_collate_names(name, name_len, al_name,
  933                                         al_name_len, 1, IGNORE_CASE,
  934                                         vol->upcase, vol->upcase_len);
  935                         /*
  936                          * If @name collates before al_name, there is no
  937                          * matching attribute.
  938                          */
  939                         if (rc == -1)
  940                                 goto not_found;
  941                         /* If the strings are not equal, continue search. */
  942                         if (rc)
  943                                 continue;
  944                         /*
  945                          * FIXME: Reverse engineering showed 0, IGNORE_CASE but
  946                          * that is inconsistent with ntfs_attr_find().  The
  947                          * subsequent rc checks were also different.  Perhaps I
  948                          * made a mistake in one of the two.  Need to recheck
  949                          * which is correct or at least see what is going on...
  950                          * (AIA)
  951                          */
  952                         rc = ntfs_collate_names(name, name_len, al_name,
  953                                         al_name_len, 1, CASE_SENSITIVE,
  954                                         vol->upcase, vol->upcase_len);
  955                         if (rc == -1)
  956                                 goto not_found;
  957                         if (rc)
  958                                 continue;
  959                 }
  960                 /*
  961                  * The names match or @name not present and attribute is
  962                  * unnamed.  Now check @lowest_vcn.  Continue search if the
  963                  * next attribute list entry still fits @lowest_vcn.  Otherwise
  964                  * we have reached the right one or the search has failed.
  965                  */
  966                 if (lowest_vcn && (u8*)next_al_entry >= al_start            &&
  967                                 (u8*)next_al_entry + 6 < al_end             &&
  968                                 (u8*)next_al_entry + le16_to_cpu(
  969                                         next_al_entry->length) <= al_end    &&
  970                                 sle64_to_cpu(next_al_entry->lowest_vcn) <=
  971                                         lowest_vcn                          &&
  972                                 next_al_entry->type == al_entry->type       &&
  973                                 next_al_entry->name_length == al_name_len   &&
  974                                 ntfs_are_names_equal((ntfschar*)((u8*)
  975                                         next_al_entry +
  976                                         next_al_entry->name_offset),
  977                                         next_al_entry->name_length,
  978                                         al_name, al_name_len, CASE_SENSITIVE,
  979                                         vol->upcase, vol->upcase_len))
  980                         continue;
  981                 if (MREF_LE(al_entry->mft_reference) == ni->mft_no) {
  982                         if (MSEQNO_LE(al_entry->mft_reference) != ni->seq_no) {
  983                                 ntfs_error(vol->sb, "Found stale mft "
  984                                                 "reference in attribute list "
  985                                                 "of base inode 0x%lx.%s",
  986                                                 base_ni->mft_no, es);
  987                                 err = -EIO;
  988                                 break;
  989                         }
  990                 } else { /* Mft references do not match. */
  991                         /* If there is a mapped record unmap it first. */
  992                         if (ni != base_ni)
  993                                 unmap_extent_mft_record(ni);
  994                         /* Do we want the base record back? */
  995                         if (MREF_LE(al_entry->mft_reference) ==
  996                                         base_ni->mft_no) {
  997                                 ni = ctx->ntfs_ino = base_ni;
  998                                 ctx->mrec = ctx->base_mrec;
  999                         } else {
 1000                                 /* We want an extent record. */
 1001                                 ctx->mrec = map_extent_mft_record(base_ni,
 1002                                                 le64_to_cpu(
 1003                                                 al_entry->mft_reference), &ni);
 1004                                 if (IS_ERR(ctx->mrec)) {
 1005                                         ntfs_error(vol->sb, "Failed to map "
 1006                                                         "extent mft record "
 1007                                                         "0x%lx of base inode "
 1008                                                         "0x%lx.%s",
 1009                                                         MREF_LE(al_entry->
 1010                                                         mft_reference),
 1011                                                         base_ni->mft_no, es);
 1012                                         err = PTR_ERR(ctx->mrec);
 1013                                         if (err == -ENOENT)
 1014                                                 err = -EIO;
 1015                                         /* Cause @ctx to be sanitized below. */
 1016                                         ni = NULL;
 1017                                         break;
 1018                                 }
 1019                                 ctx->ntfs_ino = ni;
 1020                         }
 1021                         ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
 1022                                         le16_to_cpu(ctx->mrec->attrs_offset));
 1023                 }
 1024                 /*
 1025                  * ctx->vfs_ino, ctx->mrec, and ctx->attr now point to the
 1026                  * mft record containing the attribute represented by the
 1027                  * current al_entry.
 1028                  */
 1029                 /*
 1030                  * We could call into ntfs_attr_find() to find the right
 1031                  * attribute in this mft record but this would be less
 1032                  * efficient and not quite accurate as ntfs_attr_find() ignores
 1033                  * the attribute instance numbers for example which become
 1034                  * important when one plays with attribute lists.  Also,
 1035                  * because a proper match has been found in the attribute list
 1036                  * entry above, the comparison can now be optimized.  So it is
 1037                  * worth re-implementing a simplified ntfs_attr_find() here.
 1038                  */
 1039                 a = ctx->attr;
 1040                 /*
 1041                  * Use a manual loop so we can still use break and continue
 1042                  * with the same meanings as above.
 1043                  */
 1044 do_next_attr_loop:
 1045                 if ((u8*)a < (u8*)ctx->mrec || (u8*)a > (u8*)ctx->mrec +
 1046                                 le32_to_cpu(ctx->mrec->bytes_allocated))
 1047                         break;
 1048                 if (a->type == AT_END)
 1049                         break;
 1050                 if (!a->length)
 1051                         break;
 1052                 if (al_entry->instance != a->instance)
 1053                         goto do_next_attr;
 1054                 /*
 1055                  * If the type and/or the name are mismatched between the
 1056                  * attribute list entry and the attribute record, there is
 1057                  * corruption so we break and return error EIO.
 1058                  */
 1059                 if (al_entry->type != a->type)
 1060                         break;
 1061                 if (!ntfs_are_names_equal((ntfschar*)((u8*)a +
 1062                                 le16_to_cpu(a->name_offset)), a->name_length,
 1063                                 al_name, al_name_len, CASE_SENSITIVE,
 1064                                 vol->upcase, vol->upcase_len))
 1065                         break;
 1066                 ctx->attr = a;
 1067                 /*
 1068                  * If no @val specified or @val specified and it matches, we
 1069                  * have found it!
 1070                  */
 1071                 if (!val || (!a->non_resident && le32_to_cpu(
 1072                                 a->data.resident.value_length) == val_len &&
 1073                                 !memcmp((u8*)a +
 1074                                 le16_to_cpu(a->data.resident.value_offset),
 1075                                 val, val_len))) {
 1076                         ntfs_debug("Done, found.");
 1077                         return 0;
 1078                 }
 1079 do_next_attr:
 1080                 /* Proceed to the next attribute in the current mft record. */
 1081                 a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length));
 1082                 goto do_next_attr_loop;
 1083         }
 1084         if (!err) {
 1085                 ntfs_error(vol->sb, "Base inode 0x%lx contains corrupt "
 1086                                 "attribute list attribute.%s", base_ni->mft_no,
 1087                                 es);
 1088                 err = -EIO;
 1089         }
 1090         if (ni != base_ni) {
 1091                 if (ni)
 1092                         unmap_extent_mft_record(ni);
 1093                 ctx->ntfs_ino = base_ni;
 1094                 ctx->mrec = ctx->base_mrec;
 1095                 ctx->attr = ctx->base_attr;
 1096         }
 1097         if (err != -ENOMEM)
 1098                 NVolSetErrors(vol);
 1099         return err;
 1100 not_found:
 1101         /*
 1102          * If we were looking for AT_END, we reset the search context @ctx and
 1103          * use ntfs_attr_find() to seek to the end of the base mft record.
 1104          */
 1105         if (type == AT_END) {
 1106                 ntfs_attr_reinit_search_ctx(ctx);
 1107                 return ntfs_attr_find(AT_END, name, name_len, ic, val, val_len,
 1108                                 ctx);
 1109         }
 1110         /*
 1111          * The attribute was not found.  Before we return, we want to ensure
 1112          * @ctx->mrec and @ctx->attr indicate the position at which the
 1113          * attribute should be inserted in the base mft record.  Since we also
 1114          * want to preserve @ctx->al_entry we cannot reinitialize the search
 1115          * context using ntfs_attr_reinit_search_ctx() as this would set
 1116          * @ctx->al_entry to NULL.  Thus we do the necessary bits manually (see
 1117          * ntfs_attr_init_search_ctx() below).  Note, we _only_ preserve
 1118          * @ctx->al_entry as the remaining fields (base_*) are identical to
 1119          * their non base_ counterparts and we cannot set @ctx->base_attr
 1120          * correctly yet as we do not know what @ctx->attr will be set to by
 1121          * the call to ntfs_attr_find() below.
 1122          */
 1123         if (ni != base_ni)
 1124                 unmap_extent_mft_record(ni);
 1125         ctx->mrec = ctx->base_mrec;
 1126         ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
 1127                         le16_to_cpu(ctx->mrec->attrs_offset));
 1128         ctx->is_first = true;
 1129         ctx->ntfs_ino = base_ni;
 1130         ctx->base_ntfs_ino = NULL;
 1131         ctx->base_mrec = NULL;
 1132         ctx->base_attr = NULL;
 1133         /*
 1134          * In case there are multiple matches in the base mft record, need to
 1135          * keep enumerating until we get an attribute not found response (or
 1136          * another error), otherwise we would keep returning the same attribute
 1137          * over and over again and all programs using us for enumeration would
 1138          * lock up in a tight loop.
 1139          */
 1140         do {
 1141                 err = ntfs_attr_find(type, name, name_len, ic, val, val_len,
 1142                                 ctx);
 1143         } while (!err);
 1144         ntfs_debug("Done, not found.");
 1145         return err;
 1146 }
 1147 
 1148 /**
 1149  * ntfs_attr_lookup - find an attribute in an ntfs inode
 1150  * @type:       attribute type to find
 1151  * @name:       attribute name to find (optional, i.e. NULL means don't care)
 1152  * @name_len:   attribute name length (only needed if @name present)
 1153  * @ic:         IGNORE_CASE or CASE_SENSITIVE (ignored if @name not present)
 1154  * @lowest_vcn: lowest vcn to find (optional, non-resident attributes only)
 1155  * @val:        attribute value to find (optional, resident attributes only)
 1156  * @val_len:    attribute value length
 1157  * @ctx:        search context with mft record and attribute to search from
 1158  *
 1159  * Find an attribute in an ntfs inode.  On first search @ctx->ntfs_ino must
 1160  * be the base mft record and @ctx must have been obtained from a call to
 1161  * ntfs_attr_get_search_ctx().
 1162  *
 1163  * This function transparently handles attribute lists and @ctx is used to
 1164  * continue searches where they were left off at.
 1165  *
 1166  * After finishing with the attribute/mft record you need to call
 1167  * ntfs_attr_put_search_ctx() to cleanup the search context (unmapping any
 1168  * mapped inodes, etc).
 1169  *
 1170  * Return 0 if the search was successful and -errno if not.
 1171  *
 1172  * When 0, @ctx->attr is the found attribute and it is in mft record
 1173  * @ctx->mrec.  If an attribute list attribute is present, @ctx->al_entry is
 1174  * the attribute list entry of the found attribute.
 1175  *
 1176  * When -ENOENT, @ctx->attr is the attribute which collates just after the
 1177  * attribute being searched for, i.e. if one wants to add the attribute to the
 1178  * mft record this is the correct place to insert it into.  If an attribute
 1179  * list attribute is present, @ctx->al_entry is the attribute list entry which
 1180  * collates just after the attribute list entry of the attribute being searched
 1181  * for, i.e. if one wants to add the attribute to the mft record this is the
 1182  * correct place to insert its attribute list entry into.
 1183  *
 1184  * When -errno != -ENOENT, an error occurred during the lookup.  @ctx->attr is
 1185  * then undefined and in particular you should not rely on it not changing.
 1186  */
 1187 int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
 1188                 const u32 name_len, const IGNORE_CASE_BOOL ic,
 1189                 const VCN lowest_vcn, const u8 *val, const u32 val_len,
 1190                 ntfs_attr_search_ctx *ctx)
 1191 {
 1192         ntfs_inode *base_ni;
 1193 
 1194         ntfs_debug("Entering.");
 1195         BUG_ON(IS_ERR(ctx->mrec));
 1196         if (ctx->base_ntfs_ino)
 1197                 base_ni = ctx->base_ntfs_ino;
 1198         else
 1199                 base_ni = ctx->ntfs_ino;
 1200         /* Sanity check, just for debugging really. */
 1201         BUG_ON(!base_ni);
 1202         if (!NInoAttrList(base_ni) || type == AT_ATTRIBUTE_LIST)
 1203                 return ntfs_attr_find(type, name, name_len, ic, val, val_len,
 1204                                 ctx);
 1205         return ntfs_external_attr_find(type, name, name_len, ic, lowest_vcn,
 1206                         val, val_len, ctx);
 1207 }
 1208 
 1209 /**
 1210  * ntfs_attr_init_search_ctx - initialize an attribute search context
 1211  * @ctx:        attribute search context to initialize
 1212  * @ni:         ntfs inode with which to initialize the search context
 1213  * @mrec:       mft record with which to initialize the search context
 1214  *
 1215  * Initialize the attribute search context @ctx with @ni and @mrec.
 1216  */
 1217 static inline void ntfs_attr_init_search_ctx(ntfs_attr_search_ctx *ctx,
 1218                 ntfs_inode *ni, MFT_RECORD *mrec)
 1219 {
 1220         *ctx = (ntfs_attr_search_ctx) {
 1221                 .mrec = mrec,
 1222                 /* Sanity checks are performed elsewhere. */
 1223                 .attr = (ATTR_RECORD*)((u8*)mrec +
 1224                                 le16_to_cpu(mrec->attrs_offset)),
 1225                 .is_first = true,
 1226                 .ntfs_ino = ni,
 1227         };
 1228 }
 1229 
 1230 /**
 1231  * ntfs_attr_reinit_search_ctx - reinitialize an attribute search context
 1232  * @ctx:        attribute search context to reinitialize
 1233  *
 1234  * Reinitialize the attribute search context @ctx, unmapping an associated
 1235  * extent mft record if present, and initialize the search context again.
 1236  *
 1237  * This is used when a search for a new attribute is being started to reset
 1238  * the search context to the beginning.
 1239  */
 1240 void ntfs_attr_reinit_search_ctx(ntfs_attr_search_ctx *ctx)
 1241 {
 1242         if (likely(!ctx->base_ntfs_ino)) {
 1243                 /* No attribute list. */
 1244                 ctx->is_first = true;
 1245                 /* Sanity checks are performed elsewhere. */
 1246                 ctx->attr = (ATTR_RECORD*)((u8*)ctx->mrec +
 1247                                 le16_to_cpu(ctx->mrec->attrs_offset));
 1248                 /*
 1249                  * This needs resetting due to ntfs_external_attr_find() which
 1250                  * can leave it set despite having zeroed ctx->base_ntfs_ino.
 1251                  */
 1252                 ctx->al_entry = NULL;
 1253                 return;
 1254         } /* Attribute list. */
 1255         if (ctx->ntfs_ino != ctx->base_ntfs_ino)
 1256                 unmap_extent_mft_record(ctx->ntfs_ino);
 1257         ntfs_attr_init_search_ctx(ctx, ctx->base_ntfs_ino, ctx->base_mrec);
 1258         return;
 1259 }
 1260 
 1261 /**
 1262  * ntfs_attr_get_search_ctx - allocate/initialize a new attribute search context
 1263  * @ni:         ntfs inode with which to initialize the search context
 1264  * @mrec:       mft record with which to initialize the search context
 1265  *
 1266  * Allocate a new attribute search context, initialize it with @ni and @mrec,
 1267  * and return it. Return NULL if allocation failed.
 1268  */
 1269 ntfs_attr_search_ctx *ntfs_attr_get_search_ctx(ntfs_inode *ni, MFT_RECORD *mrec)
 1270 {
 1271         ntfs_attr_search_ctx *ctx;
 1272 
 1273         ctx = kmem_cache_alloc(ntfs_attr_ctx_cache, GFP_NOFS);
 1274         if (ctx)
 1275                 ntfs_attr_init_search_ctx(ctx, ni, mrec);
 1276         return ctx;
 1277 }
 1278 
 1279 /**
 1280  * ntfs_attr_put_search_ctx - release an attribute search context
 1281  * @ctx:        attribute search context to free
 1282  *
 1283  * Release the attribute search context @ctx, unmapping an associated extent
 1284  * mft record if present.
 1285  */
 1286 void ntfs_attr_put_search_ctx(ntfs_attr_search_ctx *ctx)
 1287 {
 1288         if (ctx->base_ntfs_ino && ctx->ntfs_ino != ctx->base_ntfs_ino)
 1289                 unmap_extent_mft_record(ctx->ntfs_ino);
 1290         kmem_cache_free(ntfs_attr_ctx_cache, ctx);
 1291         return;
 1292 }
 1293 
 1294 #ifdef NTFS_RW
 1295 
 1296 /**
 1297  * ntfs_attr_find_in_attrdef - find an attribute in the $AttrDef system file
 1298  * @vol:        ntfs volume to which the attribute belongs
 1299  * @type:       attribute type which to find
 1300  *
 1301  * Search for the attribute definition record corresponding to the attribute
 1302  * @type in the $AttrDef system file.
 1303  *
 1304  * Return the attribute type definition record if found and NULL if not found.
 1305  */
 1306 static ATTR_DEF *ntfs_attr_find_in_attrdef(const ntfs_volume *vol,
 1307                 const ATTR_TYPE type)
 1308 {
 1309         ATTR_DEF *ad;
 1310 
 1311         BUG_ON(!vol->attrdef);
 1312         BUG_ON(!type);
 1313         for (ad = vol->attrdef; (u8*)ad - (u8*)vol->attrdef <
 1314                         vol->attrdef_size && ad->type; ++ad) {
 1315                 /* We have not found it yet, carry on searching. */
 1316                 if (likely(le32_to_cpu(ad->type) < le32_to_cpu(type)))
 1317                         continue;
 1318                 /* We found the attribute; return it. */
 1319                 if (likely(ad->type == type))
 1320                         return ad;
 1321                 /* We have gone too far already.  No point in continuing. */
 1322                 break;
 1323         }
 1324         /* Attribute not found. */
 1325         ntfs_debug("Attribute type 0x%x not found in $AttrDef.",
 1326                         le32_to_cpu(type));
 1327         return NULL;
 1328 }
 1329 
 1330 /**
 1331  * ntfs_attr_size_bounds_check - check a size of an attribute type for validity
 1332  * @vol:        ntfs volume to which the attribute belongs
 1333  * @type:       attribute type which to check
 1334  * @size:       size which to check
 1335  *
 1336  * Check whether the @size in bytes is valid for an attribute of @type on the
 1337  * ntfs volume @vol.  This information is obtained from $AttrDef system file.
 1338  *
 1339  * Return 0 if valid, -ERANGE if not valid, or -ENOENT if the attribute is not
 1340  * listed in $AttrDef.
 1341  */
 1342 int ntfs_attr_size_bounds_check(const ntfs_volume *vol, const ATTR_TYPE type,
 1343                 const s64 size)
 1344 {
 1345         ATTR_DEF *ad;
 1346 
 1347         BUG_ON(size < 0);
 1348         /*
 1349          * $ATTRIBUTE_LIST has a maximum size of 256kiB, but this is not
 1350          * listed in $AttrDef.
 1351          */
 1352         if (unlikely(type == AT_ATTRIBUTE_LIST && size > 256 * 1024))
 1353                 return -ERANGE;
 1354         /* Get the $AttrDef entry for the attribute @type. */
 1355         ad = ntfs_attr_find_in_attrdef(vol, type);
 1356         if (unlikely(!ad))
 1357                 return -ENOENT;
 1358         /* Do the bounds check. */
 1359         if (((sle64_to_cpu(ad->min_size) > 0) &&
 1360                         size < sle64_to_cpu(ad->min_size)) ||
 1361                         ((sle64_to_cpu(ad->max_size) > 0) && size >
 1362                         sle64_to_cpu(ad->max_size)))
 1363                 return -ERANGE;
 1364         return 0;
 1365 }
 1366 
 1367 /**
 1368  * ntfs_attr_can_be_non_resident - check if an attribute can be non-resident
 1369  * @vol:        ntfs volume to which the attribute belongs
 1370  * @type:       attribute type which to check
 1371  *
 1372  * Check whether the attribute of @type on the ntfs volume @vol is allowed to
 1373  * be non-resident.  This information is obtained from $AttrDef system file.
 1374  *
 1375  * Return 0 if the attribute is allowed to be non-resident, -EPERM if not, and
 1376  * -ENOENT if the attribute is not listed in $AttrDef.
 1377  */
 1378 int ntfs_attr_can_be_non_resident(const ntfs_volume *vol, const ATTR_TYPE type)
 1379 {
 1380         ATTR_DEF *ad;
 1381 
 1382         /* Find the attribute definition record in $AttrDef. */
 1383         ad = ntfs_attr_find_in_attrdef(vol, type);
 1384         if (unlikely(!ad))
 1385                 return -ENOENT;
 1386         /* Check the flags and return the result. */
 1387         if (ad->flags & ATTR_DEF_RESIDENT)
 1388                 return -EPERM;
 1389         return 0;
 1390 }
 1391 
 1392 /**
 1393  * ntfs_attr_can_be_resident - check if an attribute can be resident
 1394  * @vol:        ntfs volume to which the attribute belongs
 1395  * @type:       attribute type which to check
 1396  *
 1397  * Check whether the attribute of @type on the ntfs volume @vol is allowed to
 1398  * be resident.  This information is derived from our ntfs knowledge and may
 1399  * not be completely accurate, especially when user defined attributes are
 1400  * present.  Basically we allow everything to be resident except for index
 1401  * allocation and $EA attributes.
 1402  *
 1403  * Return 0 if the attribute is allowed to be non-resident and -EPERM if not.
 1404  *
 1405  * Warning: In the system file $MFT the attribute $Bitmap must be non-resident
 1406  *          otherwise windows will not boot (blue screen of death)!  We cannot
 1407  *          check for this here as we do not know which inode's $Bitmap is
 1408  *          being asked about so the caller needs to special case this.
 1409  */
 1410 int ntfs_attr_can_be_resident(const ntfs_volume *vol, const ATTR_TYPE type)
 1411 {
 1412         if (type == AT_INDEX_ALLOCATION)
 1413                 return -EPERM;
 1414         return 0;
 1415 }
 1416 
 1417 /**
 1418  * ntfs_attr_record_resize - resize an attribute record
 1419  * @m:          mft record containing attribute record
 1420  * @a:          attribute record to resize
 1421  * @new_size:   new size in bytes to which to resize the attribute record @a
 1422  *
 1423  * Resize the attribute record @a, i.e. the resident part of the attribute, in
 1424  * the mft record @m to @new_size bytes.
 1425  *
 1426  * Return 0 on success and -errno on error.  The following error codes are
 1427  * defined:
 1428  *      -ENOSPC - Not enough space in the mft record @m to perform the resize.
 1429  *
 1430  * Note: On error, no modifications have been performed whatsoever.
 1431  *
 1432  * Warning: If you make a record smaller without having copied all the data you
 1433  *          are interested in the data may be overwritten.
 1434  */
 1435 int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
 1436 {
 1437         ntfs_debug("Entering for new_size %u.", new_size);
 1438         /* Align to 8 bytes if it is not already done. */
 1439         if (new_size & 7)
 1440                 new_size = (new_size + 7) & ~7;
 1441         /* If the actual attribute length has changed, move things around. */
 1442         if (new_size != le32_to_cpu(a->length)) {
 1443                 u32 new_muse = le32_to_cpu(m->bytes_in_use) -
 1444                                 le32_to_cpu(a->length) + new_size;
 1445                 /* Not enough space in this mft record. */
 1446                 if (new_muse > le32_to_cpu(m->bytes_allocated))
 1447                         return -ENOSPC;
 1448                 /* Move attributes following @a to their new location. */
 1449                 memmove((u8*)a + new_size, (u8*)a + le32_to_cpu(a->length),
 1450                                 le32_to_cpu(m->bytes_in_use) - ((u8*)a -
 1451                                 (u8*)m) - le32_to_cpu(a->length));
 1452                 /* Adjust @m to reflect the change in used space. */
 1453                 m->bytes_in_use = cpu_to_le32(new_muse);
 1454                 /* Adjust @a to reflect the new size. */
 1455                 if (new_size >= offsetof(ATTR_REC, length) + sizeof(a->length))
 1456                         a->length = cpu_to_le32(new_size);
 1457         }
 1458         return 0;
 1459 }
 1460 
 1461 /**
 1462  * ntfs_resident_attr_value_resize - resize the value of a resident attribute
 1463  * @m:          mft record containing attribute record
 1464  * @a:          attribute record whose value to resize
 1465  * @new_size:   new size in bytes to which to resize the attribute value of @a
 1466  *
 1467  * Resize the value of the attribute @a in the mft record @m to @new_size bytes.
 1468  * If the value is made bigger, the newly allocated space is cleared.
 1469  *
 1470  * Return 0 on success and -errno on error.  The following error codes are
 1471  * defined:
 1472  *      -ENOSPC - Not enough space in the mft record @m to perform the resize.
 1473  *
 1474  * Note: On error, no modifications have been performed whatsoever.
 1475  *
 1476  * Warning: If you make a record smaller without having copied all the data you
 1477  *          are interested in the data may be overwritten.
 1478  */
 1479 int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
 1480                 const u32 new_size)
 1481 {
 1482         u32 old_size;
 1483 
 1484         /* Resize the resident part of the attribute record. */
 1485         if (ntfs_attr_record_resize(m, a,
 1486                         le16_to_cpu(a->data.resident.value_offset) + new_size))
 1487                 return -ENOSPC;
 1488         /*
 1489          * The resize succeeded!  If we made the attribute value bigger, clear
 1490          * the area between the old size and @new_size.
 1491          */
 1492         old_size = le32_to_cpu(a->data.resident.value_length);
 1493         if (new_size > old_size)
 1494                 memset((u8*)a + le16_to_cpu(a->data.resident.value_offset) +
 1495                                 old_size, 0, new_size - old_size);
 1496         /* Finally update the length of the attribute value. */
 1497         a->data.resident.value_length = cpu_to_le32(new_size);
 1498         return 0;
 1499 }
 1500 
 1501 /**
 1502  * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute
 1503  * @ni:         ntfs inode describing the attribute to convert
 1504  * @data_size:  size of the resident data to copy to the non-resident attribute
 1505  *
 1506  * Convert the resident ntfs attribute described by the ntfs inode @ni to a
 1507  * non-resident one.
 1508  *
 1509  * @data_size must be equal to the attribute value size.  This is needed since
 1510  * we need to know the size before we can map the mft record and our callers
 1511  * always know it.  The reason we cannot simply read the size from the vfs
 1512  * inode i_size is that this is not necessarily uptodate.  This happens when
 1513  * ntfs_attr_make_non_resident() is called in the ->truncate call path(s).
 1514  *
 1515  * Return 0 on success and -errno on error.  The following error return codes
 1516  * are defined:
 1517  *      -EPERM  - The attribute is not allowed to be non-resident.
 1518  *      -ENOMEM - Not enough memory.
 1519  *      -ENOSPC - Not enough disk space.
 1520  *      -EINVAL - Attribute not defined on the volume.
 1521  *      -EIO    - I/o error or other error.
 1522  * Note that -ENOSPC is also returned in the case that there is not enough
 1523  * space in the mft record to do the conversion.  This can happen when the mft
 1524  * record is already very full.  The caller is responsible for trying to make
 1525  * space in the mft record and trying again.  FIXME: Do we need a separate
 1526  * error return code for this kind of -ENOSPC or is it always worth trying
 1527  * again in case the attribute may then fit in a resident state so no need to
 1528  * make it non-resident at all?  Ho-hum...  (AIA)
 1529  *
 1530  * NOTE to self: No changes in the attribute list are required to move from
 1531  *               a resident to a non-resident attribute.
 1532  *
 1533  * Locking: - The caller must hold i_mutex on the inode.
 1534  */
 1535 int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size)
 1536 {
 1537         s64 new_size;
 1538         struct inode *vi = VFS_I(ni);
 1539         ntfs_volume *vol = ni->vol;
 1540         ntfs_inode *base_ni;
 1541         MFT_RECORD *m;
 1542         ATTR_RECORD *a;
 1543         ntfs_attr_search_ctx *ctx;
 1544         struct page *page;
 1545         runlist_element *rl;
 1546         u8 *kaddr;
 1547         unsigned long flags;
 1548         int mp_size, mp_ofs, name_ofs, arec_size, err, err2;
 1549         u32 attr_size;
 1550         u8 old_res_attr_flags;
 1551 
 1552         /* Check that the attribute is allowed to be non-resident. */
 1553         err = ntfs_attr_can_be_non_resident(vol, ni->type);
 1554         if (unlikely(err)) {
 1555                 if (err == -EPERM)
 1556                         ntfs_debug("Attribute is not allowed to be "
 1557                                         "non-resident.");
 1558                 else
 1559                         ntfs_debug("Attribute not defined on the NTFS "
 1560                                         "volume!");
 1561                 return err;
 1562         }
 1563         /*
 1564          * FIXME: Compressed and encrypted attributes are not supported when
 1565          * writing and we should never have gotten here for them.
 1566          */
 1567         BUG_ON(NInoCompressed(ni));
 1568         BUG_ON(NInoEncrypted(ni));
 1569         /*
 1570          * The size needs to be aligned to a cluster boundary for allocation
 1571          * purposes.
 1572          */
 1573         new_size = (data_size + vol->cluster_size - 1) &
 1574                         ~(vol->cluster_size - 1);
 1575         if (new_size > 0) {
 1576                 /*
 1577                  * Will need the page later and since the page lock nests
 1578                  * outside all ntfs locks, we need to get the page now.
 1579                  */
 1580                 page = find_or_create_page(vi->i_mapping, 0,
 1581                                 mapping_gfp_mask(vi->i_mapping));
 1582                 if (unlikely(!page))
 1583                         return -ENOMEM;
 1584                 /* Start by allocating clusters to hold the attribute value. */
 1585                 rl = ntfs_cluster_alloc(vol, 0, new_size >>
 1586                                 vol->cluster_size_bits, -1, DATA_ZONE, true);
 1587                 if (IS_ERR(rl)) {
 1588                         err = PTR_ERR(rl);
 1589                         ntfs_debug("Failed to allocate cluster%s, error code "
 1590                                         "%i.", (new_size >>
 1591                                         vol->cluster_size_bits) > 1 ? "s" : "",
 1592                                         err);
 1593                         goto page_err_out;
 1594                 }
 1595         } else {
 1596                 rl = NULL;
 1597                 page = NULL;
 1598         }
 1599         /* Determine the size of the mapping pairs array. */
 1600         mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0, -1);
 1601         if (unlikely(mp_size < 0)) {
 1602                 err = mp_size;
 1603                 ntfs_debug("Failed to get size for mapping pairs array, error "
 1604                                 "code %i.", err);
 1605                 goto rl_err_out;
 1606         }
 1607         down_write(&ni->runlist.lock);
 1608         if (!NInoAttr(ni))
 1609                 base_ni = ni;
 1610         else
 1611                 base_ni = ni->ext.base_ntfs_ino;
 1612         m = map_mft_record(base_ni);
 1613         if (IS_ERR(m)) {
 1614                 err = PTR_ERR(m);
 1615                 m = NULL;
 1616                 ctx = NULL;
 1617                 goto err_out;
 1618         }
 1619         ctx = ntfs_attr_get_search_ctx(base_ni, m);
 1620         if (unlikely(!ctx)) {
 1621                 err = -ENOMEM;
 1622                 goto err_out;
 1623         }
 1624         err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
 1625                         CASE_SENSITIVE, 0, NULL, 0, ctx);
 1626         if (unlikely(err)) {
 1627                 if (err == -ENOENT)
 1628                         err = -EIO;
 1629                 goto err_out;
 1630         }
 1631         m = ctx->mrec;
 1632         a = ctx->attr;
 1633         BUG_ON(NInoNonResident(ni));
 1634         BUG_ON(a->non_resident);
 1635         /*
 1636          * Calculate new offsets for the name and the mapping pairs array.
 1637          */
 1638         if (NInoSparse(ni) || NInoCompressed(ni))
 1639                 name_ofs = (offsetof(ATTR_REC,
 1640                                 data.non_resident.compressed_size) +
 1641                                 sizeof(a->data.non_resident.compressed_size) +
 1642                                 7) & ~7;
 1643         else
 1644                 name_ofs = (offsetof(ATTR_REC,
 1645                                 data.non_resident.compressed_size) + 7) & ~7;
 1646         mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
 1647         /*
 1648          * Determine the size of the resident part of the now non-resident
 1649          * attribute record.
 1650          */
 1651         arec_size = (mp_ofs + mp_size + 7) & ~7;
 1652         /*
 1653          * If the page is not uptodate bring it uptodate by copying from the
 1654          * attribute value.
 1655          */
 1656         attr_size = le32_to_cpu(a->data.resident.value_length);
 1657         BUG_ON(attr_size != data_size);
 1658         if (page && !PageUptodate(page)) {
 1659                 kaddr = kmap_atomic(page);
 1660                 memcpy(kaddr, (u8*)a +
 1661                                 le16_to_cpu(a->data.resident.value_offset),
 1662                                 attr_size);
 1663                 memset(kaddr + attr_size, 0, PAGE_CACHE_SIZE - attr_size);
 1664                 kunmap_atomic(kaddr);
 1665                 flush_dcache_page(page);
 1666                 SetPageUptodate(page);
 1667         }
 1668         /* Backup the attribute flag. */
 1669         old_res_attr_flags = a->data.resident.flags;
 1670         /* Resize the resident part of the attribute record. */
 1671         err = ntfs_attr_record_resize(m, a, arec_size);
 1672         if (unlikely(err))
 1673                 goto err_out;
 1674         /*
 1675          * Convert the resident part of the attribute record to describe a
 1676          * non-resident attribute.
 1677          */
 1678         a->non_resident = 1;
 1679         /* Move the attribute name if it exists and update the offset. */
 1680         if (a->name_length)
 1681                 memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
 1682                                 a->name_length * sizeof(ntfschar));
 1683         a->name_offset = cpu_to_le16(name_ofs);
 1684         /* Setup the fields specific to non-resident attributes. */
 1685         a->data.non_resident.lowest_vcn = 0;
 1686         a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >>
 1687                         vol->cluster_size_bits);
 1688         a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
 1689         memset(&a->data.non_resident.reserved, 0,
 1690                         sizeof(a->data.non_resident.reserved));
 1691         a->data.non_resident.allocated_size = cpu_to_sle64(new_size);
 1692         a->data.non_resident.data_size =
 1693                         a->data.non_resident.initialized_size =
 1694                         cpu_to_sle64(attr_size);
 1695         if (NInoSparse(ni) || NInoCompressed(ni)) {
 1696                 a->data.non_resident.compression_unit = 0;
 1697                 if (NInoCompressed(ni) || vol->major_ver < 3)
 1698                         a->data.non_resident.compression_unit = 4;
 1699                 a->data.non_resident.compressed_size =
 1700                                 a->data.non_resident.allocated_size;
 1701         } else
 1702                 a->data.non_resident.compression_unit = 0;
 1703         /* Generate the mapping pairs array into the attribute record. */
 1704         err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs,
 1705                         arec_size - mp_ofs, rl, 0, -1, NULL);
 1706         if (unlikely(err)) {
 1707                 ntfs_debug("Failed to build mapping pairs, error code %i.",
 1708                                 err);
 1709                 goto undo_err_out;
 1710         }
 1711         /* Setup the in-memory attribute structure to be non-resident. */
 1712         ni->runlist.rl = rl;
 1713         write_lock_irqsave(&ni->size_lock, flags);
 1714         ni->allocated_size = new_size;
 1715         if (NInoSparse(ni) || NInoCompressed(ni)) {
 1716                 ni->itype.compressed.size = ni->allocated_size;
 1717                 if (a->data.non_resident.compression_unit) {
 1718                         ni->itype.compressed.block_size = 1U << (a->data.
 1719                                         non_resident.compression_unit +
 1720                                         vol->cluster_size_bits);
 1721                         ni->itype.compressed.block_size_bits =
 1722                                         ffs(ni->itype.compressed.block_size) -
 1723                                         1;
 1724                         ni->itype.compressed.block_clusters = 1U <<
 1725                                         a->data.non_resident.compression_unit;
 1726                 } else {
 1727                         ni->itype.compressed.block_size = 0;
 1728                         ni->itype.compressed.block_size_bits = 0;
 1729                         ni->itype.compressed.block_clusters = 0;
 1730                 }
 1731                 vi->i_blocks = ni->itype.compressed.size >> 9;
 1732         } else
 1733                 vi->i_blocks = ni->allocated_size >> 9;
 1734         write_unlock_irqrestore(&ni->size_lock, flags);
 1735         /*
 1736          * This needs to be last since the address space operations ->readpage
 1737          * and ->writepage can run concurrently with us as they are not
 1738          * serialized on i_mutex.  Note, we are not allowed to fail once we flip
 1739          * this switch, which is another reason to do this last.
 1740          */
 1741         NInoSetNonResident(ni);
 1742         /* Mark the mft record dirty, so it gets written back. */
 1743         flush_dcache_mft_record_page(ctx->ntfs_ino);
 1744         mark_mft_record_dirty(ctx->ntfs_ino);
 1745         ntfs_attr_put_search_ctx(ctx);
 1746         unmap_mft_record(base_ni);
 1747         up_write(&ni->runlist.lock);
 1748         if (page) {
 1749                 set_page_dirty(page);
 1750                 unlock_page(page);
 1751                 mark_page_accessed(page);
 1752                 page_cache_release(page);
 1753         }
 1754         ntfs_debug("Done.");
 1755         return 0;
 1756 undo_err_out:
 1757         /* Convert the attribute back into a resident attribute. */
 1758         a->non_resident = 0;
 1759         /* Move the attribute name if it exists and update the offset. */
 1760         name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) +
 1761                         sizeof(a->data.resident.reserved) + 7) & ~7;
 1762         if (a->name_length)
 1763                 memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset),
 1764                                 a->name_length * sizeof(ntfschar));
 1765         mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7;
 1766         a->name_offset = cpu_to_le16(name_ofs);
 1767         arec_size = (mp_ofs + attr_size + 7) & ~7;
 1768         /* Resize the resident part of the attribute record. */
 1769         err2 = ntfs_attr_record_resize(m, a, arec_size);
 1770         if (unlikely(err2)) {
 1771                 /*
 1772                  * This cannot happen (well if memory corruption is at work it
 1773                  * could happen in theory), but deal with it as well as we can.
 1774                  * If the old size is too small, truncate the attribute,
 1775                  * otherwise simply give it a larger allocated size.
 1776                  * FIXME: Should check whether chkdsk complains when the
 1777                  * allocated size is much bigger than the resident value size.
 1778                  */
 1779                 arec_size = le32_to_cpu(a->length);
 1780                 if ((mp_ofs + attr_size) > arec_size) {
 1781                         err2 = attr_size;
 1782                         attr_size = arec_size - mp_ofs;
 1783                         ntfs_error(vol->sb, "Failed to undo partial resident "
 1784                                         "to non-resident attribute "
 1785                                         "conversion.  Truncating inode 0x%lx, "
 1786                                         "attribute type 0x%x from %i bytes to "
 1787                                         "%i bytes to maintain metadata "
 1788                                         "consistency.  THIS MEANS YOU ARE "
 1789                                         "LOSING %i BYTES DATA FROM THIS %s.",
 1790                                         vi->i_ino,
 1791                                         (unsigned)le32_to_cpu(ni->type),
 1792                                         err2, attr_size, err2 - attr_size,
 1793                                         ((ni->type == AT_DATA) &&
 1794                                         !ni->name_len) ? "FILE": "ATTRIBUTE");
 1795                         write_lock_irqsave(&ni->size_lock, flags);
 1796                         ni->initialized_size = attr_size;
 1797                         i_size_write(vi, attr_size);
 1798                         write_unlock_irqrestore(&ni->size_lock, flags);
 1799                 }
 1800         }
 1801         /* Setup the fields specific to resident attributes. */
 1802         a->data.resident.value_length = cpu_to_le32(attr_size);
 1803         a->data.resident.value_offset = cpu_to_le16(mp_ofs);
 1804         a->data.resident.flags = old_res_attr_flags;
 1805         memset(&a->data.resident.reserved, 0,
 1806                         sizeof(a->data.resident.reserved));
 1807         /* Copy the data from the page back to the attribute value. */
 1808         if (page) {
 1809                 kaddr = kmap_atomic(page);
 1810                 memcpy((u8*)a + mp_ofs, kaddr, attr_size);
 1811                 kunmap_atomic(kaddr);
 1812         }
 1813         /* Setup the allocated size in the ntfs inode in case it changed. */
 1814         write_lock_irqsave(&ni->size_lock, flags);
 1815         ni->allocated_size = arec_size - mp_ofs;
 1816         write_unlock_irqrestore(&ni->size_lock, flags);
 1817         /* Mark the mft record dirty, so it gets written back. */
 1818         flush_dcache_mft_record_page(ctx->ntfs_ino);
 1819         mark_mft_record_dirty(ctx->ntfs_ino);
 1820 err_out:
 1821         if (ctx)
 1822                 ntfs_attr_put_search_ctx(ctx);
 1823         if (m)
 1824                 unmap_mft_record(base_ni);
 1825         ni->runlist.rl = NULL;
 1826         up_write(&ni->runlist.lock);
 1827 rl_err_out:
 1828         if (rl) {
 1829                 if (ntfs_cluster_free_from_rl(vol, rl) < 0) {
 1830                         ntfs_error(vol->sb, "Failed to release allocated "
 1831                                         "cluster(s) in error code path.  Run "
 1832                                         "chkdsk to recover the lost "
 1833                                         "cluster(s).");
 1834                         NVolSetErrors(vol);
 1835                 }
 1836                 ntfs_free(rl);
 1837 page_err_out:
 1838                 unlock_page(page);
 1839                 page_cache_release(page);
 1840         }
 1841         if (err == -EINVAL)
 1842                 err = -EIO;
 1843         return err;
 1844 }
 1845 
 1846 /**
 1847  * ntfs_attr_extend_allocation - extend the allocated space of an attribute
 1848  * @ni:                 ntfs inode of the attribute whose allocation to extend
 1849  * @new_alloc_size:     new size in bytes to which to extend the allocation to
 1850  * @new_data_size:      new size in bytes to which to extend the data to
 1851  * @data_start:         beginning of region which is required to be non-sparse
 1852  *
 1853  * Extend the allocated space of an attribute described by the ntfs inode @ni
 1854  * to @new_alloc_size bytes.  If @data_start is -1, the whole extension may be
 1855  * implemented as a hole in the file (as long as both the volume and the ntfs
 1856  * inode @ni have sparse support enabled).  If @data_start is >= 0, then the
 1857  * region between the old allocated size and @data_start - 1 may be made sparse
 1858  * but the regions between @data_start and @new_alloc_size must be backed by
 1859  * actual clusters.
 1860  *
 1861  * If @new_data_size is -1, it is ignored.  If it is >= 0, then the data size
 1862  * of the attribute is extended to @new_data_size.  Note that the i_size of the
 1863  * vfs inode is not updated.  Only the data size in the base attribute record
 1864  * is updated.  The caller has to update i_size separately if this is required.
 1865  * WARNING: It is a BUG() for @new_data_size to be smaller than the old data
 1866  * size as well as for @new_data_size to be greater than @new_alloc_size.
 1867  *
 1868  * For resident attributes this involves resizing the attribute record and if
 1869  * necessary moving it and/or other attributes into extent mft records and/or
 1870  * converting the attribute to a non-resident attribute which in turn involves
 1871  * extending the allocation of a non-resident attribute as described below.
 1872  *
 1873  * For non-resident attributes this involves allocating clusters in the data
 1874  * zone on the volume (except for regions that are being made sparse) and
 1875  * extending the run list to describe the allocated clusters as well as
 1876  * updating the mapping pairs array of the attribute.  This in turn involves
 1877  * resizing the attribute record and if necessary moving it and/or other
 1878  * attributes into extent mft records and/or splitting the attribute record
 1879  * into multiple extent attribute records.
 1880  *
 1881  * Also, the attribute list attribute is updated if present and in some of the
 1882  * above cases (the ones where extent mft records/attributes come into play),
 1883  * an attribute list attribute is created if not already present.
 1884  *
 1885  * Return the new allocated size on success and -errno on error.  In the case
 1886  * that an error is encountered but a partial extension at least up to
 1887  * @data_start (if present) is possible, the allocation is partially extended
 1888  * and this is returned.  This means the caller must check the returned size to
 1889  * determine if the extension was partial.  If @data_start is -1 then partial
 1890  * allocations are not performed.
 1891  *
 1892  * WARNING: Do not call ntfs_attr_extend_allocation() for $MFT/$DATA.
 1893  *
 1894  * Locking: This function takes the runlist lock of @ni for writing as well as
 1895  * locking the mft record of the base ntfs inode.  These locks are maintained
 1896  * throughout execution of the function.  These locks are required so that the
 1897  * attribute can be resized safely and so that it can for example be converted
 1898  * from resident to non-resident safely.
 1899  *
 1900  * TODO: At present attribute list attribute handling is not implemented.
 1901  *
 1902  * TODO: At present it is not safe to call this function for anything other
 1903  * than the $DATA attribute(s) of an uncompressed and unencrypted file.
 1904  */
 1905 s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
 1906                 const s64 new_data_size, const s64 data_start)
 1907 {
 1908         VCN vcn;
 1909         s64 ll, allocated_size, start = data_start;
 1910         struct inode *vi = VFS_I(ni);
 1911         ntfs_volume *vol = ni->vol;
 1912         ntfs_inode *base_ni;
 1913         MFT_RECORD *m;
 1914         ATTR_RECORD *a;
 1915         ntfs_attr_search_ctx *ctx;
 1916         runlist_element *rl, *rl2;
 1917         unsigned long flags;
 1918         int err, mp_size;
 1919         u32 attr_len = 0; /* Silence stupid gcc warning. */
 1920         bool mp_rebuilt;
 1921 
 1922 #ifdef DEBUG
 1923         read_lock_irqsave(&ni->size_lock, flags);
 1924         allocated_size = ni->allocated_size;
 1925         read_unlock_irqrestore(&ni->size_lock, flags);
 1926         ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
 1927                         "old_allocated_size 0x%llx, "
 1928                         "new_allocated_size 0x%llx, new_data_size 0x%llx, "
 1929                         "data_start 0x%llx.", vi->i_ino,
 1930                         (unsigned)le32_to_cpu(ni->type),
 1931                         (unsigned long long)allocated_size,
 1932                         (unsigned long long)new_alloc_size,
 1933                         (unsigned long long)new_data_size,
 1934                         (unsigned long long)start);
 1935 #endif
 1936 retry_extend:
 1937         /*
 1938          * For non-resident attributes, @start and @new_size need to be aligned
 1939          * to cluster boundaries for allocation purposes.
 1940          */
 1941         if (NInoNonResident(ni)) {
 1942                 if (start > 0)
 1943                         start &= ~(s64)vol->cluster_size_mask;
 1944                 new_alloc_size = (new_alloc_size + vol->cluster_size - 1) &
 1945                                 ~(s64)vol->cluster_size_mask;
 1946         }
 1947         BUG_ON(new_data_size >= 0 && new_data_size > new_alloc_size);
 1948         /* Check if new size is allowed in $AttrDef. */
 1949         err = ntfs_attr_size_bounds_check(vol, ni->type, new_alloc_size);
 1950         if (unlikely(err)) {
 1951                 /* Only emit errors when the write will fail completely. */
 1952                 read_lock_irqsave(&ni->size_lock, flags);
 1953                 allocated_size = ni->allocated_size;
 1954                 read_unlock_irqrestore(&ni->size_lock, flags);
 1955                 if (start < 0 || start >= allocated_size) {
 1956                         if (err == -ERANGE) {
 1957                                 ntfs_error(vol->sb, "Cannot extend allocation "
 1958                                                 "of inode 0x%lx, attribute "
 1959                                                 "type 0x%x, because the new "
 1960                                                 "allocation would exceed the "
 1961                                                 "maximum allowed size for "
 1962                                                 "this attribute type.",
 1963                                                 vi->i_ino, (unsigned)
 1964                                                 le32_to_cpu(ni->type));
 1965                         } else {
 1966                                 ntfs_error(vol->sb, "Cannot extend allocation "
 1967                                                 "of inode 0x%lx, attribute "
 1968                                                 "type 0x%x, because this "
 1969                                                 "attribute type is not "
 1970                                                 "defined on the NTFS volume.  "
 1971                                                 "Possible corruption!  You "
 1972                                                 "should run chkdsk!",
 1973                                                 vi->i_ino, (unsigned)
 1974                                                 le32_to_cpu(ni->type));
 1975                         }
 1976                 }
 1977                 /* Translate error code to be POSIX conformant for write(2). */
 1978                 if (err == -ERANGE)
 1979                         err = -EFBIG;
 1980                 else
 1981                         err = -EIO;
 1982                 return err;
 1983         }
 1984         if (!NInoAttr(ni))
 1985                 base_ni = ni;
 1986         else
 1987                 base_ni = ni->ext.base_ntfs_ino;
 1988         /*
 1989          * We will be modifying both the runlist (if non-resident) and the mft
 1990          * record so lock them both down.
 1991          */
 1992         down_write(&ni->runlist.lock);
 1993         m = map_mft_record(base_ni);
 1994         if (IS_ERR(m)) {
 1995                 err = PTR_ERR(m);
 1996                 m = NULL;
 1997                 ctx = NULL;
 1998                 goto err_out;
 1999         }
 2000         ctx = ntfs_attr_get_search_ctx(base_ni, m);
 2001         if (unlikely(!ctx)) {
 2002                 err = -ENOMEM;
 2003                 goto err_out;
 2004         }
 2005         read_lock_irqsave(&ni->size_lock, flags);
 2006         allocated_size = ni->allocated_size;
 2007         read_unlock_irqrestore(&ni->size_lock, flags);
 2008         /*
 2009          * If non-resident, seek to the last extent.  If resident, there is
 2010          * only one extent, so seek to that.
 2011          */
 2012         vcn = NInoNonResident(ni) ? allocated_size >> vol->cluster_size_bits :
 2013                         0;
 2014         /*
 2015          * Abort if someone did the work whilst we waited for the locks.  If we
 2016          * just converted the attribute from resident to non-resident it is
 2017          * likely that exactly this has happened already.  We cannot quite
 2018          * abort if we need to update the data size.
 2019          */
 2020         if (unlikely(new_alloc_size <= allocated_size)) {
 2021                 ntfs_debug("Allocated size already exceeds requested size.");
 2022                 new_alloc_size = allocated_size;
 2023                 if (new_data_size < 0)
 2024                         goto done;
 2025                 /*
 2026                  * We want the first attribute extent so that we can update the
 2027                  * data size.
 2028                  */
 2029                 vcn = 0;
 2030         }
 2031         err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
 2032                         CASE_SENSITIVE, vcn, NULL, 0, ctx);
 2033         if (unlikely(err)) {
 2034                 if (err == -ENOENT)
 2035                         err = -EIO;
 2036                 goto err_out;
 2037         }
 2038         m = ctx->mrec;
 2039         a = ctx->attr;
 2040         /* Use goto to reduce indentation. */
 2041         if (a->non_resident)
 2042                 goto do_non_resident_extend;
 2043         BUG_ON(NInoNonResident(ni));
 2044         /* The total length of the attribute value. */
 2045         attr_len = le32_to_cpu(a->data.resident.value_length);
 2046         /*
 2047          * Extend the attribute record to be able to store the new attribute
 2048          * size.  ntfs_attr_record_resize() will not do anything if the size is
 2049          * not changing.
 2050          */
 2051         if (new_alloc_size < vol->mft_record_size &&
 2052                         !ntfs_attr_record_resize(m, a,
 2053                         le16_to_cpu(a->data.resident.value_offset) +
 2054                         new_alloc_size)) {
 2055                 /* The resize succeeded! */
 2056                 write_lock_irqsave(&ni->size_lock, flags);
 2057                 ni->allocated_size = le32_to_cpu(a->length) -
 2058                                 le16_to_cpu(a->data.resident.value_offset);
 2059                 write_unlock_irqrestore(&ni->size_lock, flags);
 2060                 if (new_data_size >= 0) {
 2061                         BUG_ON(new_data_size < attr_len);
 2062                         a->data.resident.value_length =
 2063                                         cpu_to_le32((u32)new_data_size);
 2064                 }
 2065                 goto flush_done;
 2066         }
 2067         /*
 2068          * We have to drop all the locks so we can call
 2069          * ntfs_attr_make_non_resident().  This could be optimised by try-
 2070          * locking the first page cache page and only if that fails dropping
 2071          * the locks, locking the page, and redoing all the locking and
 2072          * lookups.  While this would be a huge optimisation, it is not worth
 2073          * it as this is definitely a slow code path.
 2074          */
 2075         ntfs_attr_put_search_ctx(ctx);
 2076         unmap_mft_record(base_ni);
 2077         up_write(&ni->runlist.lock);
 2078         /*
 2079          * Not enough space in the mft record, try to make the attribute
 2080          * non-resident and if successful restart the extension process.
 2081          */
 2082         err = ntfs_attr_make_non_resident(ni, attr_len);
 2083         if (likely(!err))
 2084                 goto retry_extend;
 2085         /*
 2086          * Could not make non-resident.  If this is due to this not being
 2087          * permitted for this attribute type or there not being enough space,
 2088          * try to make other attributes non-resident.  Otherwise fail.
 2089          */
 2090         if (unlikely(err != -EPERM && err != -ENOSPC)) {
 2091                 /* Only emit errors when the write will fail completely. */
 2092                 read_lock_irqsave(&ni->size_lock, flags);
 2093                 allocated_size = ni->allocated_size;
 2094                 read_unlock_irqrestore(&ni->size_lock, flags);
 2095                 if (start < 0 || start >= allocated_size)
 2096                         ntfs_error(vol->sb, "Cannot extend allocation of "
 2097                                         "inode 0x%lx, attribute type 0x%x, "
 2098                                         "because the conversion from resident "
 2099                                         "to non-resident attribute failed "
 2100                                         "with error code %i.", vi->i_ino,
 2101                                         (unsigned)le32_to_cpu(ni->type), err);
 2102                 if (err != -ENOMEM)
 2103                         err = -EIO;
 2104                 goto conv_err_out;
 2105         }
 2106         /* TODO: Not implemented from here, abort. */
 2107         read_lock_irqsave(&ni->size_lock, flags);
 2108         allocated_size = ni->allocated_size;
 2109         read_unlock_irqrestore(&ni->size_lock, flags);
 2110         if (start < 0 || start >= allocated_size) {
 2111                 if (err == -ENOSPC)
 2112                         ntfs_error(vol->sb, "Not enough space in the mft "
 2113                                         "record/on disk for the non-resident "
 2114                                         "attribute value.  This case is not "
 2115                                         "implemented yet.");
 2116                 else /* if (err == -EPERM) */
 2117                         ntfs_error(vol->sb, "This attribute type may not be "
 2118                                         "non-resident.  This case is not "
 2119                                         "implemented yet.");
 2120         }
 2121         err = -EOPNOTSUPP;
 2122         goto conv_err_out;
 2123 #if 0
 2124         // TODO: Attempt to make other attributes non-resident.
 2125         if (!err)
 2126                 goto do_resident_extend;
 2127         /*
 2128          * Both the attribute list attribute and the standard information
 2129          * attribute must remain in the base inode.  Thus, if this is one of
 2130          * these attributes, we have to try to move other attributes out into
 2131          * extent mft records instead.
 2132          */
 2133         if (ni->type == AT_ATTRIBUTE_LIST ||
 2134                         ni->type == AT_STANDARD_INFORMATION) {
 2135                 // TODO: Attempt to move other attributes into extent mft
 2136                 // records.
 2137                 err = -EOPNOTSUPP;
 2138                 if (!err)
 2139                         goto do_resident_extend;
 2140                 goto err_out;
 2141         }
 2142         // TODO: Attempt to move this attribute to an extent mft record, but
 2143         // only if it is not already the only attribute in an mft record in
 2144         // which case there would be nothing to gain.
 2145         err = -EOPNOTSUPP;
 2146         if (!err)
 2147                 goto do_resident_extend;
 2148         /* There is nothing we can do to make enough space. )-: */
 2149         goto err_out;
 2150 #endif
 2151 do_non_resident_extend:
 2152         BUG_ON(!NInoNonResident(ni));
 2153         if (new_alloc_size == allocated_size) {
 2154                 BUG_ON(vcn);
 2155                 goto alloc_done;
 2156         }
 2157         /*
 2158          * If the data starts after the end of the old allocation, this is a
 2159          * $DATA attribute and sparse attributes are enabled on the volume and
 2160          * for this inode, then create a sparse region between the old
 2161          * allocated size and the start of the data.  Otherwise simply proceed
 2162          * with filling the whole space between the old allocated size and the
 2163          * new allocated size with clusters.
 2164          */
 2165         if ((start >= 0 && start <= allocated_size) || ni->type != AT_DATA ||
 2166                         !NVolSparseEnabled(vol) || NInoSparseDisabled(ni))
 2167                 goto skip_sparse;
 2168         // TODO: This is not implemented yet.  We just fill in with real
 2169         // clusters for now...
 2170         ntfs_debug("Inserting holes is not-implemented yet.  Falling back to "
 2171                         "allocating real clusters instead.");
 2172 skip_sparse:
 2173         rl = ni->runlist.rl;
 2174         if (likely(rl)) {
 2175                 /* Seek to the end of the runlist. */
 2176                 while (rl->length)
 2177                         rl++;
 2178         }
 2179         /* If this attribute extent is not mapped, map it now. */
 2180         if (unlikely(!rl || rl->lcn == LCN_RL_NOT_MAPPED ||
 2181                         (rl->lcn == LCN_ENOENT && rl > ni->runlist.rl &&
 2182                         (rl-1)->lcn == LCN_RL_NOT_MAPPED))) {
 2183                 if (!rl && !allocated_size)
 2184                         goto first_alloc;
 2185                 rl = ntfs_mapping_pairs_decompress(vol, a, ni->runlist.rl);
 2186                 if (IS_ERR(rl)) {
 2187                         err = PTR_ERR(rl);
 2188                         if (start < 0 || start >= allocated_size)
 2189                                 ntfs_error(vol->sb, "Cannot extend allocation "
 2190                                                 "of inode 0x%lx, attribute "
 2191                                                 "type 0x%x, because the "
 2192                                                 "mapping of a runlist "
 2193                                                 "fragment failed with error "
 2194                                                 "code %i.", vi->i_ino,
 2195                                                 (unsigned)le32_to_cpu(ni->type),
 2196                                                 err);
 2197                         if (err != -ENOMEM)
 2198                                 err = -EIO;
 2199                         goto err_out;
 2200                 }
 2201                 ni->runlist.rl = rl;
 2202                 /* Seek to the end of the runlist. */
 2203                 while (rl->length)
 2204                         rl++;
 2205         }
 2206         /*
 2207          * We now know the runlist of the last extent is mapped and @rl is at
 2208          * the end of the runlist.  We want to begin allocating clusters
 2209          * starting at the last allocated cluster to reduce fragmentation.  If
 2210          * there are no valid LCNs in the attribute we let the cluster
 2211          * allocator choose the starting cluster.
 2212          */
 2213         /* If the last LCN is a hole or simillar seek back to last real LCN. */
 2214         while (rl->lcn < 0 && rl > ni->runlist.rl)
 2215                 rl--;
 2216 first_alloc:
 2217         // FIXME: Need to implement partial allocations so at least part of the
 2218         // write can be performed when start >= 0.  (Needed for POSIX write(2)
 2219         // conformance.)
 2220         rl2 = ntfs_cluster_alloc(vol, allocated_size >> vol->cluster_size_bits,
 2221                         (new_alloc_size - allocated_size) >>
 2222                         vol->cluster_size_bits, (rl && (rl->lcn >= 0)) ?
 2223                         rl->lcn + rl->length : -1, DATA_ZONE, true);
 2224         if (IS_ERR(rl2)) {
 2225                 err = PTR_ERR(rl2);
 2226                 if (start < 0 || start >= allocated_size)
 2227                         ntfs_error(vol->sb, "Cannot extend allocation of "
 2228                                         "inode 0x%lx, attribute type 0x%x, "
 2229                                         "because the allocation of clusters "
 2230                                         "failed with error code %i.", vi->i_ino,
 2231                                         (unsigned)le32_to_cpu(ni->type), err);
 2232                 if (err != -ENOMEM && err != -ENOSPC)
 2233                         err = -EIO;
 2234                 goto err_out;
 2235         }
 2236         rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
 2237         if (IS_ERR(rl)) {
 2238                 err = PTR_ERR(rl);
 2239                 if (start < 0 || start >= allocated_size)
 2240                         ntfs_error(vol->sb, "Cannot extend allocation of "
 2241                                         "inode 0x%lx, attribute type 0x%x, "
 2242                                         "because the runlist merge failed "
 2243                                         "with error code %i.", vi->i_ino,
 2244                                         (unsigned)le32_to_cpu(ni->type), err);
 2245                 if (err != -ENOMEM)
 2246                         err = -EIO;
 2247                 if (ntfs_cluster_free_from_rl(vol, rl2)) {
 2248                         ntfs_error(vol->sb, "Failed to release allocated "
 2249                                         "cluster(s) in error code path.  Run "
 2250                                         "chkdsk to recover the lost "
 2251                                         "cluster(s).");
 2252                         NVolSetErrors(vol);
 2253                 }
 2254                 ntfs_free(rl2);
 2255                 goto err_out;
 2256         }
 2257         ni->runlist.rl = rl;
 2258         ntfs_debug("Allocated 0x%llx clusters.", (long long)(new_alloc_size -
 2259                         allocated_size) >> vol->cluster_size_bits);
 2260         /* Find the runlist element with which the attribute extent starts. */
 2261         ll = sle64_to_cpu(a->data.non_resident.lowest_vcn);
 2262         rl2 = ntfs_rl_find_vcn_nolock(rl, ll);
 2263         BUG_ON(!rl2);
 2264         BUG_ON(!rl2->length);
 2265         BUG_ON(rl2->lcn < LCN_HOLE);
 2266         mp_rebuilt = false;
 2267         /* Get the size for the new mapping pairs array for this extent. */
 2268         mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, ll, -1);
 2269         if (unlikely(mp_size <= 0)) {
 2270                 err = mp_size;
 2271                 if (start < 0 || start >= allocated_size)
 2272                         ntfs_error(vol->sb, "Cannot extend allocation of "
 2273                                         "inode 0x%lx, attribute type 0x%x, "
 2274                                         "because determining the size for the "
 2275                                         "mapping pairs failed with error code "
 2276                                         "%i.", vi->i_ino,
 2277                                         (unsigned)le32_to_cpu(ni->type), err);
 2278                 err = -EIO;
 2279                 goto undo_alloc;
 2280         }
 2281         /* Extend the attribute record to fit the bigger mapping pairs array. */
 2282         attr_len = le32_to_cpu(a->length);
 2283         err = ntfs_attr_record_resize(m, a, mp_size +
 2284                         le16_to_cpu(a->data.non_resident.mapping_pairs_offset));
 2285         if (unlikely(err)) {
 2286                 BUG_ON(err != -ENOSPC);
 2287                 // TODO: Deal with this by moving this extent to a new mft
 2288                 // record or by starting a new extent in a new mft record,
 2289                 // possibly by extending this extent partially and filling it
 2290                 // and creating a new extent for the remainder, or by making
 2291                 // other attributes non-resident and/or by moving other
 2292                 // attributes out of this mft record.
 2293                 if (start < 0 || start >= allocated_size)
 2294                         ntfs_error(vol->sb, "Not enough space in the mft "
 2295                                         "record for the extended attribute "
 2296                                         "record.  This case is not "
 2297                                         "implemented yet.");
 2298                 err = -EOPNOTSUPP;
 2299                 goto undo_alloc;
 2300         }
 2301         mp_rebuilt = true;
 2302         /* Generate the mapping pairs array directly into the attr record. */
 2303         err = ntfs_mapping_pairs_build(vol, (u8*)a +
 2304                         le16_to_cpu(a->data.non_resident.mapping_pairs_offset),
 2305                         mp_size, rl2, ll, -1, NULL);
 2306         if (unlikely(err)) {
 2307                 if (start < 0 || start >= allocated_size)
 2308                         ntfs_error(vol->sb, "Cannot extend allocation of "
 2309                                         "inode 0x%lx, attribute type 0x%x, "
 2310                                         "because building the mapping pairs "
 2311                                         "failed with error code %i.", vi->i_ino,
 2312                                         (unsigned)le32_to_cpu(ni->type), err);
 2313                 err = -EIO;
 2314                 goto undo_alloc;
 2315         }
 2316         /* Update the highest_vcn. */
 2317         a->data.non_resident.highest_vcn = cpu_to_sle64((new_alloc_size >>
 2318                         vol->cluster_size_bits) - 1);
 2319         /*
 2320          * We now have extended the allocated size of the attribute.  Reflect
 2321          * this in the ntfs_inode structure and the attribute record.
 2322          */
 2323         if (a->data.non_resident.lowest_vcn) {
 2324                 /*
 2325                  * We are not in the first attribute extent, switch to it, but
 2326                  * first ensure the changes will make it to disk later.
 2327                  */
 2328                 flush_dcache_mft_record_page(ctx->ntfs_ino);
 2329                 mark_mft_record_dirty(ctx->ntfs_ino);
 2330                 ntfs_attr_reinit_search_ctx(ctx);
 2331                 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
 2332                                 CASE_SENSITIVE, 0, NULL, 0, ctx);
 2333                 if (unlikely(err))
 2334                         goto restore_undo_alloc;
 2335                 /* @m is not used any more so no need to set it. */
 2336                 a = ctx->attr;
 2337         }
 2338         write_lock_irqsave(&ni->size_lock, flags);
 2339         ni->allocated_size = new_alloc_size;
 2340         a->data.non_resident.allocated_size = cpu_to_sle64(new_alloc_size);
 2341         /*
 2342          * FIXME: This would fail if @ni is a directory, $MFT, or an index,
 2343          * since those can have sparse/compressed set.  For example can be
 2344          * set compressed even though it is not compressed itself and in that
 2345          * case the bit means that files are to be created compressed in the
 2346          * directory...  At present this is ok as this code is only called for
 2347          * regular files, and only for their $DATA attribute(s).
 2348          * FIXME: The calculation is wrong if we created a hole above.  For now
 2349          * it does not matter as we never create holes.
 2350          */
 2351         if (NInoSparse(ni) || NInoCompressed(ni)) {
 2352                 ni->itype.compressed.size += new_alloc_size - allocated_size;
 2353                 a->data.non_resident.compressed_size =
 2354                                 cpu_to_sle64(ni->itype.compressed.size);
 2355                 vi->i_blocks = ni->itype.compressed.size >> 9;
 2356         } else
 2357                 vi->i_blocks = new_alloc_size >> 9;
 2358         write_unlock_irqrestore(&ni->size_lock, flags);
 2359 alloc_done:
 2360         if (new_data_size >= 0) {
 2361                 BUG_ON(new_data_size <
 2362                                 sle64_to_cpu(a->data.non_resident.data_size));
 2363                 a->data.non_resident.data_size = cpu_to_sle64(new_data_size);
 2364         }
 2365 flush_done:
 2366         /* Ensure the changes make it to disk. */
 2367         flush_dcache_mft_record_page(ctx->ntfs_ino);
 2368         mark_mft_record_dirty(ctx->ntfs_ino);
 2369 done:
 2370         ntfs_attr_put_search_ctx(ctx);
 2371         unmap_mft_record(base_ni);
 2372         up_write(&ni->runlist.lock);
 2373         ntfs_debug("Done, new_allocated_size 0x%llx.",
 2374                         (unsigned long long)new_alloc_size);
 2375         return new_alloc_size;
 2376 restore_undo_alloc:
 2377         if (start < 0 || start >= allocated_size)
 2378                 ntfs_error(vol->sb, "Cannot complete extension of allocation "
 2379                                 "of inode 0x%lx, attribute type 0x%x, because "
 2380                                 "lookup of first attribute extent failed with "
 2381                                 "error code %i.", vi->i_ino,
 2382                                 (unsigned)le32_to_cpu(ni->type), err);
 2383         if (err == -ENOENT)
 2384                 err = -EIO;
 2385         ntfs_attr_reinit_search_ctx(ctx);
 2386         if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len, CASE_SENSITIVE,
 2387                         allocated_size >> vol->cluster_size_bits, NULL, 0,
 2388                         ctx)) {
 2389                 ntfs_error(vol->sb, "Failed to find last attribute extent of "
 2390                                 "attribute in error code path.  Run chkdsk to "
 2391                                 "recover.");
 2392                 write_lock_irqsave(&ni->size_lock, flags);
 2393                 ni->allocated_size = new_alloc_size;
 2394                 /*
 2395                  * FIXME: This would fail if @ni is a directory...  See above.
 2396                  * FIXME: The calculation is wrong if we created a hole above.
 2397                  * For now it does not matter as we never create holes.
 2398                  */
 2399                 if (NInoSparse(ni) || NInoCompressed(ni)) {
 2400                         ni->itype.compressed.size += new_alloc_size -
 2401                                         allocated_size;
 2402                         vi->i_blocks = ni->itype.compressed.size >> 9;
 2403                 } else
 2404                         vi->i_blocks = new_alloc_size >> 9;
 2405                 write_unlock_irqrestore(&ni->size_lock, flags);
 2406                 ntfs_attr_put_search_ctx(ctx);
 2407                 unmap_mft_record(base_ni);
 2408                 up_write(&ni->runlist.lock);
 2409                 /*
 2410                  * The only thing that is now wrong is the allocated size of the
 2411                  * base attribute extent which chkdsk should be able to fix.
 2412                  */
 2413                 NVolSetErrors(vol);
 2414                 return err;
 2415         }
 2416         ctx->attr->data.non_resident.highest_vcn = cpu_to_sle64(
 2417                         (allocated_size >> vol->cluster_size_bits) - 1);
 2418 undo_alloc:
 2419         ll = allocated_size >> vol->cluster_size_bits;
 2420         if (ntfs_cluster_free(ni, ll, -1, ctx) < 0) {
 2421                 ntfs_error(vol->sb, "Failed to release allocated cluster(s) "
 2422                                 "in error code path.  Run chkdsk to recover "
 2423                                 "the lost cluster(s).");
 2424                 NVolSetErrors(vol);
 2425         }
 2426         m = ctx->mrec;
 2427         a = ctx->attr;
 2428         /*
 2429          * If the runlist truncation fails and/or the search context is no
 2430          * longer valid, we cannot resize the attribute record or build the
 2431          * mapping pairs array thus we mark the inode bad so that no access to
 2432          * the freed clusters can happen.
 2433          */
 2434         if (ntfs_rl_truncate_nolock(vol, &ni->runlist, ll) || IS_ERR(m)) {
 2435                 ntfs_error(vol->sb, "Failed to %s in error code path.  Run "
 2436                                 "chkdsk to recover.", IS_ERR(m) ?
 2437                                 "restore attribute search context" :
 2438                                 "truncate attribute runlist");
 2439                 NVolSetErrors(vol);
 2440         } else if (mp_rebuilt) {
 2441                 if (ntfs_attr_record_resize(m, a, attr_len)) {
 2442                         ntfs_error(vol->sb, "Failed to restore attribute "
 2443                                         "record in error code path.  Run "
 2444                                         "chkdsk to recover.");
 2445                         NVolSetErrors(vol);
 2446                 } else /* if (success) */ {
 2447                         if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
 2448                                         a->data.non_resident.
 2449                                         mapping_pairs_offset), attr_len -
 2450                                         le16_to_cpu(a->data.non_resident.
 2451                                         mapping_pairs_offset), rl2, ll, -1,
 2452                                         NULL)) {
 2453                                 ntfs_error(vol->sb, "Failed to restore "
 2454                                                 "mapping pairs array in error "
 2455                                                 "code path.  Run chkdsk to "
 2456                                                 "recover.");
 2457                                 NVolSetErrors(vol);
 2458                         }
 2459                         flush_dcache_mft_record_page(ctx->ntfs_ino);
 2460                         mark_mft_record_dirty(ctx->ntfs_ino);
 2461                 }
 2462         }
 2463 err_out:
 2464         if (ctx)
 2465                 ntfs_attr_put_search_ctx(ctx);
 2466         if (m)
 2467                 unmap_mft_record(base_ni);
 2468         up_write(&ni->runlist.lock);
 2469 conv_err_out:
 2470         ntfs_debug("Failed.  Returning error code %i.", err);
 2471         return err;
 2472 }
 2473 
 2474 /**
 2475  * ntfs_attr_set - fill (a part of) an attribute with a byte
 2476  * @ni:         ntfs inode describing the attribute to fill
 2477  * @ofs:        offset inside the attribute at which to start to fill
 2478  * @cnt:        number of bytes to fill
 2479  * @val:        the unsigned 8-bit value with which to fill the attribute
 2480  *
 2481  * Fill @cnt bytes of the attribute described by the ntfs inode @ni starting at
 2482  * byte offset @ofs inside the attribute with the constant byte @val.
 2483  *
 2484  * This function is effectively like memset() applied to an ntfs attribute.
 2485  * Note thie function actually only operates on the page cache pages belonging
 2486  * to the ntfs attribute and it marks them dirty after doing the memset().
 2487  * Thus it relies on the vm dirty page write code paths to cause the modified
 2488  * pages to be written to the mft record/disk.
 2489  *
 2490  * Return 0 on success and -errno on error.  An error code of -ESPIPE means
 2491  * that @ofs + @cnt were outside the end of the attribute and no write was
 2492  * performed.
 2493  */
 2494 int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
 2495 {
 2496         ntfs_volume *vol = ni->vol;
 2497         struct address_space *mapping;
 2498         struct page *page;
 2499         u8 *kaddr;
 2500         pgoff_t idx, end;
 2501         unsigned start_ofs, end_ofs, size;
 2502 
 2503         ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.",
 2504                         (long long)ofs, (long long)cnt, val);
 2505         BUG_ON(ofs < 0);
 2506         BUG_ON(cnt < 0);
 2507         if (!cnt)
 2508                 goto done;
 2509         /*
 2510          * FIXME: Compressed and encrypted attributes are not supported when
 2511          * writing and we should never have gotten here for them.
 2512          */
 2513         BUG_ON(NInoCompressed(ni));
 2514         BUG_ON(NInoEncrypted(ni));
 2515         mapping = VFS_I(ni)->i_mapping;
 2516         /* Work out the starting index and page offset. */
 2517         idx = ofs >> PAGE_CACHE_SHIFT;
 2518         start_ofs = ofs & ~PAGE_CACHE_MASK;
 2519         /* Work out the ending index and page offset. */
 2520         end = ofs + cnt;
 2521         end_ofs = end & ~PAGE_CACHE_MASK;
 2522         /* If the end is outside the inode size return -ESPIPE. */
 2523         if (unlikely(end > i_size_read(VFS_I(ni)))) {
 2524                 ntfs_error(vol->sb, "Request exceeds end of attribute.");
 2525                 return -ESPIPE;
 2526         }
 2527         end >>= PAGE_CACHE_SHIFT;
 2528         /* If there is a first partial page, need to do it the slow way. */
 2529         if (start_ofs) {
 2530                 page = read_mapping_page(mapping, idx, NULL);
 2531                 if (IS_ERR(page)) {
 2532                         ntfs_error(vol->sb, "Failed to read first partial "
 2533                                         "page (error, index 0x%lx).", idx);
 2534                         return PTR_ERR(page);
 2535                 }
 2536                 /*
 2537                  * If the last page is the same as the first page, need to
 2538                  * limit the write to the end offset.
 2539                  */
 2540                 size = PAGE_CACHE_SIZE;
 2541                 if (idx == end)
 2542                         size = end_ofs;
 2543                 kaddr = kmap_atomic(page);
 2544                 memset(kaddr + start_ofs, val, size - start_ofs);
 2545                 flush_dcache_page(page);
 2546                 kunmap_atomic(kaddr);
 2547                 set_page_dirty(page);
 2548                 page_cache_release(page);
 2549                 balance_dirty_pages_ratelimited(mapping);
 2550                 cond_resched();
 2551                 if (idx == end)
 2552                         goto done;
 2553                 idx++;
 2554         }
 2555         /* Do the whole pages the fast way. */
 2556         for (; idx < end; idx++) {
 2557                 /* Find or create the current page.  (The page is locked.) */
 2558                 page = grab_cache_page(mapping, idx);
 2559                 if (unlikely(!page)) {
 2560                         ntfs_error(vol->sb, "Insufficient memory to grab "
 2561                                         "page (index 0x%lx).", idx);
 2562                         return -ENOMEM;
 2563                 }
 2564                 kaddr = kmap_atomic(page);
 2565                 memset(kaddr, val, PAGE_CACHE_SIZE);
 2566                 flush_dcache_page(page);
 2567                 kunmap_atomic(kaddr);
 2568                 /*
 2569                  * If the page has buffers, mark them uptodate since buffer
 2570                  * state and not page state is definitive in 2.6 kernels.
 2571                  */
 2572                 if (page_has_buffers(page)) {
 2573                         struct buffer_head *bh, *head;
 2574 
 2575                         bh = head = page_buffers(page);
 2576                         do {
 2577                                 set_buffer_uptodate(bh);
 2578                         } while ((bh = bh->b_this_page) != head);
 2579                 }
 2580                 /* Now that buffers are uptodate, set the page uptodate, too. */
 2581                 SetPageUptodate(page);
 2582                 /*
 2583                  * Set the page and all its buffers dirty and mark the inode
 2584                  * dirty, too.  The VM will write the page later on.
 2585                  */
 2586                 set_page_dirty(page);
 2587                 /* Finally unlock and release the page. */
 2588                 unlock_page(page);
 2589                 page_cache_release(page);
 2590                 balance_dirty_pages_ratelimited(mapping);
 2591                 cond_resched();
 2592         }
 2593         /* If there is a last partial page, need to do it the slow way. */
 2594         if (end_ofs) {
 2595                 page = read_mapping_page(mapping, idx, NULL);
 2596                 if (IS_ERR(page)) {
 2597                         ntfs_error(vol->sb, "Failed to read last partial page "
 2598                                         "(error, index 0x%lx).", idx);
 2599                         return PTR_ERR(page);
 2600                 }
 2601                 kaddr = kmap_atomic(page);
 2602                 memset(kaddr, val, end_ofs);
 2603                 flush_dcache_page(page);
 2604                 kunmap_atomic(kaddr);
 2605                 set_page_dirty(page);
 2606                 page_cache_release(page);
 2607                 balance_dirty_pages_ratelimited(mapping);
 2608                 cond_resched();
 2609         }
 2610 done:
 2611         ntfs_debug("Done.");
 2612         return 0;
 2613 }
 2614 
 2615 #endif /* NTFS_RW */

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