Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/fs/ntfs/super.c

  1 /*
  2  * super.c - NTFS kernel super block handling. Part of the Linux-NTFS project.
  3  *
  4  * Copyright (c) 2001-2012 Anton Altaparmakov and Tuxera Inc.
  5  * Copyright (c) 2001,2002 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 23 
 24 #include <linux/stddef.h>
 25 #include <linux/init.h>
 26 #include <linux/slab.h>
 27 #include <linux/string.h>
 28 #include <linux/spinlock.h>
 29 #include <linux/blkdev.h>       /* For bdev_logical_block_size(). */
 30 #include <linux/backing-dev.h>
 31 #include <linux/buffer_head.h>
 32 #include <linux/vfs.h>
 33 #include <linux/moduleparam.h>
 34 #include <linux/bitmap.h>
 35 
 36 #include "sysctl.h"
 37 #include "logfile.h"
 38 #include "quota.h"
 39 #include "usnjrnl.h"
 40 #include "dir.h"
 41 #include "debug.h"
 42 #include "index.h"
 43 #include "inode.h"
 44 #include "aops.h"
 45 #include "layout.h"
 46 #include "malloc.h"
 47 #include "ntfs.h"
 48 
 49 /* Number of mounted filesystems which have compression enabled. */
 50 static unsigned long ntfs_nr_compression_users;
 51 
 52 /* A global default upcase table and a corresponding reference count. */
 53 static ntfschar *default_upcase;
 54 static unsigned long ntfs_nr_upcase_users;
 55 
 56 /* Error constants/strings used in inode.c::ntfs_show_options(). */
 57 typedef enum {
 58         /* One of these must be present, default is ON_ERRORS_CONTINUE. */
 59         ON_ERRORS_PANIC                 = 0x01,
 60         ON_ERRORS_REMOUNT_RO            = 0x02,
 61         ON_ERRORS_CONTINUE              = 0x04,
 62         /* Optional, can be combined with any of the above. */
 63         ON_ERRORS_RECOVER               = 0x10,
 64 } ON_ERRORS_ACTIONS;
 65 
 66 const option_t on_errors_arr[] = {
 67         { ON_ERRORS_PANIC,      "panic" },
 68         { ON_ERRORS_REMOUNT_RO, "remount-ro", },
 69         { ON_ERRORS_CONTINUE,   "continue", },
 70         { ON_ERRORS_RECOVER,    "recover" },
 71         { 0,                    NULL }
 72 };
 73 
 74 /**
 75  * simple_getbool -
 76  *
 77  * Copied from old ntfs driver (which copied from vfat driver).
 78  */
 79 static int simple_getbool(char *s, bool *setval)
 80 {
 81         if (s) {
 82                 if (!strcmp(s, "1") || !strcmp(s, "yes") || !strcmp(s, "true"))
 83                         *setval = true;
 84                 else if (!strcmp(s, "") || !strcmp(s, "no") ||
 85                                                         !strcmp(s, "false"))
 86                         *setval = false;
 87                 else
 88                         return 0;
 89         } else
 90                 *setval = true;
 91         return 1;
 92 }
 93 
 94 /**
 95  * parse_options - parse the (re)mount options
 96  * @vol:        ntfs volume
 97  * @opt:        string containing the (re)mount options
 98  *
 99  * Parse the recognized options in @opt for the ntfs volume described by @vol.
100  */
101 static bool parse_options(ntfs_volume *vol, char *opt)
102 {
103         char *p, *v, *ov;
104         static char *utf8 = "utf8";
105         int errors = 0, sloppy = 0;
106         kuid_t uid = INVALID_UID;
107         kgid_t gid = INVALID_GID;
108         umode_t fmask = (umode_t)-1, dmask = (umode_t)-1;
109         int mft_zone_multiplier = -1, on_errors = -1;
110         int show_sys_files = -1, case_sensitive = -1, disable_sparse = -1;
111         struct nls_table *nls_map = NULL, *old_nls;
112 
113         /* I am lazy... (-8 */
114 #define NTFS_GETOPT_WITH_DEFAULT(option, variable, default_value)       \
115         if (!strcmp(p, option)) {                                       \
116                 if (!v || !*v)                                          \
117                         variable = default_value;                       \
118                 else {                                                  \
119                         variable = simple_strtoul(ov = v, &v, 0);       \
120                         if (*v)                                         \
121                                 goto needs_val;                         \
122                 }                                                       \
123         }
124 #define NTFS_GETOPT(option, variable)                                   \
125         if (!strcmp(p, option)) {                                       \
126                 if (!v || !*v)                                          \
127                         goto needs_arg;                                 \
128                 variable = simple_strtoul(ov = v, &v, 0);               \
129                 if (*v)                                                 \
130                         goto needs_val;                                 \
131         }
132 #define NTFS_GETOPT_UID(option, variable)                               \
133         if (!strcmp(p, option)) {                                       \
134                 uid_t uid_value;                                        \
135                 if (!v || !*v)                                          \
136                         goto needs_arg;                                 \
137                 uid_value = simple_strtoul(ov = v, &v, 0);              \
138                 if (*v)                                                 \
139                         goto needs_val;                                 \
140                 variable = make_kuid(current_user_ns(), uid_value);     \
141                 if (!uid_valid(variable))                               \
142                         goto needs_val;                                 \
143         }
144 #define NTFS_GETOPT_GID(option, variable)                               \
145         if (!strcmp(p, option)) {                                       \
146                 gid_t gid_value;                                        \
147                 if (!v || !*v)                                          \
148                         goto needs_arg;                                 \
149                 gid_value = simple_strtoul(ov = v, &v, 0);              \
150                 if (*v)                                                 \
151                         goto needs_val;                                 \
152                 variable = make_kgid(current_user_ns(), gid_value);     \
153                 if (!gid_valid(variable))                               \
154                         goto needs_val;                                 \
155         }
156 #define NTFS_GETOPT_OCTAL(option, variable)                             \
157         if (!strcmp(p, option)) {                                       \
158                 if (!v || !*v)                                          \
159                         goto needs_arg;                                 \
160                 variable = simple_strtoul(ov = v, &v, 8);               \
161                 if (*v)                                                 \
162                         goto needs_val;                                 \
163         }
164 #define NTFS_GETOPT_BOOL(option, variable)                              \
165         if (!strcmp(p, option)) {                                       \
166                 bool val;                                               \
167                 if (!simple_getbool(v, &val))                           \
168                         goto needs_bool;                                \
169                 variable = val;                                         \
170         }
171 #define NTFS_GETOPT_OPTIONS_ARRAY(option, variable, opt_array)          \
172         if (!strcmp(p, option)) {                                       \
173                 int _i;                                                 \
174                 if (!v || !*v)                                          \
175                         goto needs_arg;                                 \
176                 ov = v;                                                 \
177                 if (variable == -1)                                     \
178                         variable = 0;                                   \
179                 for (_i = 0; opt_array[_i].str && *opt_array[_i].str; _i++) \
180                         if (!strcmp(opt_array[_i].str, v)) {            \
181                                 variable |= opt_array[_i].val;          \
182                                 break;                                  \
183                         }                                               \
184                 if (!opt_array[_i].str || !*opt_array[_i].str)          \
185                         goto needs_val;                                 \
186         }
187         if (!opt || !*opt)
188                 goto no_mount_options;
189         ntfs_debug("Entering with mount options string: %s", opt);
190         while ((p = strsep(&opt, ","))) {
191                 if ((v = strchr(p, '=')))
192                         *v++ = 0;
193                 NTFS_GETOPT_UID("uid", uid)
194                 else NTFS_GETOPT_GID("gid", gid)
195                 else NTFS_GETOPT_OCTAL("umask", fmask = dmask)
196                 else NTFS_GETOPT_OCTAL("fmask", fmask)
197                 else NTFS_GETOPT_OCTAL("dmask", dmask)
198                 else NTFS_GETOPT("mft_zone_multiplier", mft_zone_multiplier)
199                 else NTFS_GETOPT_WITH_DEFAULT("sloppy", sloppy, true)
200                 else NTFS_GETOPT_BOOL("show_sys_files", show_sys_files)
201                 else NTFS_GETOPT_BOOL("case_sensitive", case_sensitive)
202                 else NTFS_GETOPT_BOOL("disable_sparse", disable_sparse)
203                 else NTFS_GETOPT_OPTIONS_ARRAY("errors", on_errors,
204                                 on_errors_arr)
205                 else if (!strcmp(p, "posix") || !strcmp(p, "show_inodes"))
206                         ntfs_warning(vol->sb, "Ignoring obsolete option %s.",
207                                         p);
208                 else if (!strcmp(p, "nls") || !strcmp(p, "iocharset")) {
209                         if (!strcmp(p, "iocharset"))
210                                 ntfs_warning(vol->sb, "Option iocharset is "
211                                                 "deprecated. Please use "
212                                                 "option nls=<charsetname> in "
213                                                 "the future.");
214                         if (!v || !*v)
215                                 goto needs_arg;
216 use_utf8:
217                         old_nls = nls_map;
218                         nls_map = load_nls(v);
219                         if (!nls_map) {
220                                 if (!old_nls) {
221                                         ntfs_error(vol->sb, "NLS character set "
222                                                         "%s not found.", v);
223                                         return false;
224                                 }
225                                 ntfs_error(vol->sb, "NLS character set %s not "
226                                                 "found. Using previous one %s.",
227                                                 v, old_nls->charset);
228                                 nls_map = old_nls;
229                         } else /* nls_map */ {
230                                 unload_nls(old_nls);
231                         }
232                 } else if (!strcmp(p, "utf8")) {
233                         bool val = false;
234                         ntfs_warning(vol->sb, "Option utf8 is no longer "
235                                    "supported, using option nls=utf8. Please "
236                                    "use option nls=utf8 in the future and "
237                                    "make sure utf8 is compiled either as a "
238                                    "module or into the kernel.");
239                         if (!v || !*v)
240                                 val = true;
241                         else if (!simple_getbool(v, &val))
242                                 goto needs_bool;
243                         if (val) {
244                                 v = utf8;
245                                 goto use_utf8;
246                         }
247                 } else {
248                         ntfs_error(vol->sb, "Unrecognized mount option %s.", p);
249                         if (errors < INT_MAX)
250                                 errors++;
251                 }
252 #undef NTFS_GETOPT_OPTIONS_ARRAY
253 #undef NTFS_GETOPT_BOOL
254 #undef NTFS_GETOPT
255 #undef NTFS_GETOPT_WITH_DEFAULT
256         }
257 no_mount_options:
258         if (errors && !sloppy)
259                 return false;
260         if (sloppy)
261                 ntfs_warning(vol->sb, "Sloppy option given. Ignoring "
262                                 "unrecognized mount option(s) and continuing.");
263         /* Keep this first! */
264         if (on_errors != -1) {
265                 if (!on_errors) {
266                         ntfs_error(vol->sb, "Invalid errors option argument "
267                                         "or bug in options parser.");
268                         return false;
269                 }
270         }
271         if (nls_map) {
272                 if (vol->nls_map && vol->nls_map != nls_map) {
273                         ntfs_error(vol->sb, "Cannot change NLS character set "
274                                         "on remount.");
275                         return false;
276                 } /* else (!vol->nls_map) */
277                 ntfs_debug("Using NLS character set %s.", nls_map->charset);
278                 vol->nls_map = nls_map;
279         } else /* (!nls_map) */ {
280                 if (!vol->nls_map) {
281                         vol->nls_map = load_nls_default();
282                         if (!vol->nls_map) {
283                                 ntfs_error(vol->sb, "Failed to load default "
284                                                 "NLS character set.");
285                                 return false;
286                         }
287                         ntfs_debug("Using default NLS character set (%s).",
288                                         vol->nls_map->charset);
289                 }
290         }
291         if (mft_zone_multiplier != -1) {
292                 if (vol->mft_zone_multiplier && vol->mft_zone_multiplier !=
293                                 mft_zone_multiplier) {
294                         ntfs_error(vol->sb, "Cannot change mft_zone_multiplier "
295                                         "on remount.");
296                         return false;
297                 }
298                 if (mft_zone_multiplier < 1 || mft_zone_multiplier > 4) {
299                         ntfs_error(vol->sb, "Invalid mft_zone_multiplier. "
300                                         "Using default value, i.e. 1.");
301                         mft_zone_multiplier = 1;
302                 }
303                 vol->mft_zone_multiplier = mft_zone_multiplier;
304         }
305         if (!vol->mft_zone_multiplier)
306                 vol->mft_zone_multiplier = 1;
307         if (on_errors != -1)
308                 vol->on_errors = on_errors;
309         if (!vol->on_errors || vol->on_errors == ON_ERRORS_RECOVER)
310                 vol->on_errors |= ON_ERRORS_CONTINUE;
311         if (uid_valid(uid))
312                 vol->uid = uid;
313         if (gid_valid(gid))
314                 vol->gid = gid;
315         if (fmask != (umode_t)-1)
316                 vol->fmask = fmask;
317         if (dmask != (umode_t)-1)
318                 vol->dmask = dmask;
319         if (show_sys_files != -1) {
320                 if (show_sys_files)
321                         NVolSetShowSystemFiles(vol);
322                 else
323                         NVolClearShowSystemFiles(vol);
324         }
325         if (case_sensitive != -1) {
326                 if (case_sensitive)
327                         NVolSetCaseSensitive(vol);
328                 else
329                         NVolClearCaseSensitive(vol);
330         }
331         if (disable_sparse != -1) {
332                 if (disable_sparse)
333                         NVolClearSparseEnabled(vol);
334                 else {
335                         if (!NVolSparseEnabled(vol) &&
336                                         vol->major_ver && vol->major_ver < 3)
337                                 ntfs_warning(vol->sb, "Not enabling sparse "
338                                                 "support due to NTFS volume "
339                                                 "version %i.%i (need at least "
340                                                 "version 3.0).", vol->major_ver,
341                                                 vol->minor_ver);
342                         else
343                                 NVolSetSparseEnabled(vol);
344                 }
345         }
346         return true;
347 needs_arg:
348         ntfs_error(vol->sb, "The %s option requires an argument.", p);
349         return false;
350 needs_bool:
351         ntfs_error(vol->sb, "The %s option requires a boolean argument.", p);
352         return false;
353 needs_val:
354         ntfs_error(vol->sb, "Invalid %s option argument: %s", p, ov);
355         return false;
356 }
357 
358 #ifdef NTFS_RW
359 
360 /**
361  * ntfs_write_volume_flags - write new flags to the volume information flags
362  * @vol:        ntfs volume on which to modify the flags
363  * @flags:      new flags value for the volume information flags
364  *
365  * Internal function.  You probably want to use ntfs_{set,clear}_volume_flags()
366  * instead (see below).
367  *
368  * Replace the volume information flags on the volume @vol with the value
369  * supplied in @flags.  Note, this overwrites the volume information flags, so
370  * make sure to combine the flags you want to modify with the old flags and use
371  * the result when calling ntfs_write_volume_flags().
372  *
373  * Return 0 on success and -errno on error.
374  */
375 static int ntfs_write_volume_flags(ntfs_volume *vol, const VOLUME_FLAGS flags)
376 {
377         ntfs_inode *ni = NTFS_I(vol->vol_ino);
378         MFT_RECORD *m;
379         VOLUME_INFORMATION *vi;
380         ntfs_attr_search_ctx *ctx;
381         int err;
382 
383         ntfs_debug("Entering, old flags = 0x%x, new flags = 0x%x.",
384                         le16_to_cpu(vol->vol_flags), le16_to_cpu(flags));
385         if (vol->vol_flags == flags)
386                 goto done;
387         BUG_ON(!ni);
388         m = map_mft_record(ni);
389         if (IS_ERR(m)) {
390                 err = PTR_ERR(m);
391                 goto err_out;
392         }
393         ctx = ntfs_attr_get_search_ctx(ni, m);
394         if (!ctx) {
395                 err = -ENOMEM;
396                 goto put_unm_err_out;
397         }
398         err = ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
399                         ctx);
400         if (err)
401                 goto put_unm_err_out;
402         vi = (VOLUME_INFORMATION*)((u8*)ctx->attr +
403                         le16_to_cpu(ctx->attr->data.resident.value_offset));
404         vol->vol_flags = vi->flags = flags;
405         flush_dcache_mft_record_page(ctx->ntfs_ino);
406         mark_mft_record_dirty(ctx->ntfs_ino);
407         ntfs_attr_put_search_ctx(ctx);
408         unmap_mft_record(ni);
409 done:
410         ntfs_debug("Done.");
411         return 0;
412 put_unm_err_out:
413         if (ctx)
414                 ntfs_attr_put_search_ctx(ctx);
415         unmap_mft_record(ni);
416 err_out:
417         ntfs_error(vol->sb, "Failed with error code %i.", -err);
418         return err;
419 }
420 
421 /**
422  * ntfs_set_volume_flags - set bits in the volume information flags
423  * @vol:        ntfs volume on which to modify the flags
424  * @flags:      flags to set on the volume
425  *
426  * Set the bits in @flags in the volume information flags on the volume @vol.
427  *
428  * Return 0 on success and -errno on error.
429  */
430 static inline int ntfs_set_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
431 {
432         flags &= VOLUME_FLAGS_MASK;
433         return ntfs_write_volume_flags(vol, vol->vol_flags | flags);
434 }
435 
436 /**
437  * ntfs_clear_volume_flags - clear bits in the volume information flags
438  * @vol:        ntfs volume on which to modify the flags
439  * @flags:      flags to clear on the volume
440  *
441  * Clear the bits in @flags in the volume information flags on the volume @vol.
442  *
443  * Return 0 on success and -errno on error.
444  */
445 static inline int ntfs_clear_volume_flags(ntfs_volume *vol, VOLUME_FLAGS flags)
446 {
447         flags &= VOLUME_FLAGS_MASK;
448         flags = vol->vol_flags & cpu_to_le16(~le16_to_cpu(flags));
449         return ntfs_write_volume_flags(vol, flags);
450 }
451 
452 #endif /* NTFS_RW */
453 
454 /**
455  * ntfs_remount - change the mount options of a mounted ntfs filesystem
456  * @sb:         superblock of mounted ntfs filesystem
457  * @flags:      remount flags
458  * @opt:        remount options string
459  *
460  * Change the mount options of an already mounted ntfs filesystem.
461  *
462  * NOTE:  The VFS sets the @sb->s_flags remount flags to @flags after
463  * ntfs_remount() returns successfully (i.e. returns 0).  Otherwise,
464  * @sb->s_flags are not changed.
465  */
466 static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
467 {
468         ntfs_volume *vol = NTFS_SB(sb);
469 
470         ntfs_debug("Entering with remount options string: %s", opt);
471 
472         sync_filesystem(sb);
473 
474 #ifndef NTFS_RW
475         /* For read-only compiled driver, enforce read-only flag. */
476         *flags |= MS_RDONLY;
477 #else /* NTFS_RW */
478         /*
479          * For the read-write compiled driver, if we are remounting read-write,
480          * make sure there are no volume errors and that no unsupported volume
481          * flags are set.  Also, empty the logfile journal as it would become
482          * stale as soon as something is written to the volume and mark the
483          * volume dirty so that chkdsk is run if the volume is not umounted
484          * cleanly.  Finally, mark the quotas out of date so Windows rescans
485          * the volume on boot and updates them.
486          *
487          * When remounting read-only, mark the volume clean if no volume errors
488          * have occurred.
489          */
490         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
491                 static const char *es = ".  Cannot remount read-write.";
492 
493                 /* Remounting read-write. */
494                 if (NVolErrors(vol)) {
495                         ntfs_error(sb, "Volume has errors and is read-only%s",
496                                         es);
497                         return -EROFS;
498                 }
499                 if (vol->vol_flags & VOLUME_IS_DIRTY) {
500                         ntfs_error(sb, "Volume is dirty and read-only%s", es);
501                         return -EROFS;
502                 }
503                 if (vol->vol_flags & VOLUME_MODIFIED_BY_CHKDSK) {
504                         ntfs_error(sb, "Volume has been modified by chkdsk "
505                                         "and is read-only%s", es);
506                         return -EROFS;
507                 }
508                 if (vol->vol_flags & VOLUME_MUST_MOUNT_RO_MASK) {
509                         ntfs_error(sb, "Volume has unsupported flags set "
510                                         "(0x%x) and is read-only%s",
511                                         (unsigned)le16_to_cpu(vol->vol_flags),
512                                         es);
513                         return -EROFS;
514                 }
515                 if (ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY)) {
516                         ntfs_error(sb, "Failed to set dirty bit in volume "
517                                         "information flags%s", es);
518                         return -EROFS;
519                 }
520 #if 0
521                 // TODO: Enable this code once we start modifying anything that
522                 //       is different between NTFS 1.2 and 3.x...
523                 /* Set NT4 compatibility flag on newer NTFS version volumes. */
524                 if ((vol->major_ver > 1)) {
525                         if (ntfs_set_volume_flags(vol, VOLUME_MOUNTED_ON_NT4)) {
526                                 ntfs_error(sb, "Failed to set NT4 "
527                                                 "compatibility flag%s", es);
528                                 NVolSetErrors(vol);
529                                 return -EROFS;
530                         }
531                 }
532 #endif
533                 if (!ntfs_empty_logfile(vol->logfile_ino)) {
534                         ntfs_error(sb, "Failed to empty journal $LogFile%s",
535                                         es);
536                         NVolSetErrors(vol);
537                         return -EROFS;
538                 }
539                 if (!ntfs_mark_quotas_out_of_date(vol)) {
540                         ntfs_error(sb, "Failed to mark quotas out of date%s",
541                                         es);
542                         NVolSetErrors(vol);
543                         return -EROFS;
544                 }
545                 if (!ntfs_stamp_usnjrnl(vol)) {
546                         ntfs_error(sb, "Failed to stamp transation log "
547                                         "($UsnJrnl)%s", es);
548                         NVolSetErrors(vol);
549                         return -EROFS;
550                 }
551         } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
552                 /* Remounting read-only. */
553                 if (!NVolErrors(vol)) {
554                         if (ntfs_clear_volume_flags(vol, VOLUME_IS_DIRTY))
555                                 ntfs_warning(sb, "Failed to clear dirty bit "
556                                                 "in volume information "
557                                                 "flags.  Run chkdsk.");
558                 }
559         }
560 #endif /* NTFS_RW */
561 
562         // TODO: Deal with *flags.
563 
564         if (!parse_options(vol, opt))
565                 return -EINVAL;
566 
567         ntfs_debug("Done.");
568         return 0;
569 }
570 
571 /**
572  * is_boot_sector_ntfs - check whether a boot sector is a valid NTFS boot sector
573  * @sb:         Super block of the device to which @b belongs.
574  * @b:          Boot sector of device @sb to check.
575  * @silent:     If 'true', all output will be silenced.
576  *
577  * is_boot_sector_ntfs() checks whether the boot sector @b is a valid NTFS boot
578  * sector. Returns 'true' if it is valid and 'false' if not.
579  *
580  * @sb is only needed for warning/error output, i.e. it can be NULL when silent
581  * is 'true'.
582  */
583 static bool is_boot_sector_ntfs(const struct super_block *sb,
584                 const NTFS_BOOT_SECTOR *b, const bool silent)
585 {
586         /*
587          * Check that checksum == sum of u32 values from b to the checksum
588          * field.  If checksum is zero, no checking is done.  We will work when
589          * the checksum test fails, since some utilities update the boot sector
590          * ignoring the checksum which leaves the checksum out-of-date.  We
591          * report a warning if this is the case.
592          */
593         if ((void*)b < (void*)&b->checksum && b->checksum && !silent) {
594                 le32 *u;
595                 u32 i;
596 
597                 for (i = 0, u = (le32*)b; u < (le32*)(&b->checksum); ++u)
598                         i += le32_to_cpup(u);
599                 if (le32_to_cpu(b->checksum) != i)
600                         ntfs_warning(sb, "Invalid boot sector checksum.");
601         }
602         /* Check OEMidentifier is "NTFS    " */
603         if (b->oem_id != magicNTFS)
604                 goto not_ntfs;
605         /* Check bytes per sector value is between 256 and 4096. */
606         if (le16_to_cpu(b->bpb.bytes_per_sector) < 0x100 ||
607                         le16_to_cpu(b->bpb.bytes_per_sector) > 0x1000)
608                 goto not_ntfs;
609         /* Check sectors per cluster value is valid. */
610         switch (b->bpb.sectors_per_cluster) {
611         case 1: case 2: case 4: case 8: case 16: case 32: case 64: case 128:
612                 break;
613         default:
614                 goto not_ntfs;
615         }
616         /* Check the cluster size is not above the maximum (64kiB). */
617         if ((u32)le16_to_cpu(b->bpb.bytes_per_sector) *
618                         b->bpb.sectors_per_cluster > NTFS_MAX_CLUSTER_SIZE)
619                 goto not_ntfs;
620         /* Check reserved/unused fields are really zero. */
621         if (le16_to_cpu(b->bpb.reserved_sectors) ||
622                         le16_to_cpu(b->bpb.root_entries) ||
623                         le16_to_cpu(b->bpb.sectors) ||
624                         le16_to_cpu(b->bpb.sectors_per_fat) ||
625                         le32_to_cpu(b->bpb.large_sectors) || b->bpb.fats)
626                 goto not_ntfs;
627         /* Check clusters per file mft record value is valid. */
628         if ((u8)b->clusters_per_mft_record < 0xe1 ||
629                         (u8)b->clusters_per_mft_record > 0xf7)
630                 switch (b->clusters_per_mft_record) {
631                 case 1: case 2: case 4: case 8: case 16: case 32: case 64:
632                         break;
633                 default:
634                         goto not_ntfs;
635                 }
636         /* Check clusters per index block value is valid. */
637         if ((u8)b->clusters_per_index_record < 0xe1 ||
638                         (u8)b->clusters_per_index_record > 0xf7)
639                 switch (b->clusters_per_index_record) {
640                 case 1: case 2: case 4: case 8: case 16: case 32: case 64:
641                         break;
642                 default:
643                         goto not_ntfs;
644                 }
645         /*
646          * Check for valid end of sector marker. We will work without it, but
647          * many BIOSes will refuse to boot from a bootsector if the magic is
648          * incorrect, so we emit a warning.
649          */
650         if (!silent && b->end_of_sector_marker != cpu_to_le16(0xaa55))
651                 ntfs_warning(sb, "Invalid end of sector marker.");
652         return true;
653 not_ntfs:
654         return false;
655 }
656 
657 /**
658  * read_ntfs_boot_sector - read the NTFS boot sector of a device
659  * @sb:         super block of device to read the boot sector from
660  * @silent:     if true, suppress all output
661  *
662  * Reads the boot sector from the device and validates it. If that fails, tries
663  * to read the backup boot sector, first from the end of the device a-la NT4 and
664  * later and then from the middle of the device a-la NT3.51 and before.
665  *
666  * If a valid boot sector is found but it is not the primary boot sector, we
667  * repair the primary boot sector silently (unless the device is read-only or
668  * the primary boot sector is not accessible).
669  *
670  * NOTE: To call this function, @sb must have the fields s_dev, the ntfs super
671  * block (u.ntfs_sb), nr_blocks and the device flags (s_flags) initialized
672  * to their respective values.
673  *
674  * Return the unlocked buffer head containing the boot sector or NULL on error.
675  */
676 static struct buffer_head *read_ntfs_boot_sector(struct super_block *sb,
677                 const int silent)
678 {
679         const char *read_err_str = "Unable to read %s boot sector.";
680         struct buffer_head *bh_primary, *bh_backup;
681         sector_t nr_blocks = NTFS_SB(sb)->nr_blocks;
682 
683         /* Try to read primary boot sector. */
684         if ((bh_primary = sb_bread(sb, 0))) {
685                 if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
686                                 bh_primary->b_data, silent))
687                         return bh_primary;
688                 if (!silent)
689                         ntfs_error(sb, "Primary boot sector is invalid.");
690         } else if (!silent)
691                 ntfs_error(sb, read_err_str, "primary");
692         if (!(NTFS_SB(sb)->on_errors & ON_ERRORS_RECOVER)) {
693                 if (bh_primary)
694                         brelse(bh_primary);
695                 if (!silent)
696                         ntfs_error(sb, "Mount option errors=recover not used. "
697                                         "Aborting without trying to recover.");
698                 return NULL;
699         }
700         /* Try to read NT4+ backup boot sector. */
701         if ((bh_backup = sb_bread(sb, nr_blocks - 1))) {
702                 if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
703                                 bh_backup->b_data, silent))
704                         goto hotfix_primary_boot_sector;
705                 brelse(bh_backup);
706         } else if (!silent)
707                 ntfs_error(sb, read_err_str, "backup");
708         /* Try to read NT3.51- backup boot sector. */
709         if ((bh_backup = sb_bread(sb, nr_blocks >> 1))) {
710                 if (is_boot_sector_ntfs(sb, (NTFS_BOOT_SECTOR*)
711                                 bh_backup->b_data, silent))
712                         goto hotfix_primary_boot_sector;
713                 if (!silent)
714                         ntfs_error(sb, "Could not find a valid backup boot "
715                                         "sector.");
716                 brelse(bh_backup);
717         } else if (!silent)
718                 ntfs_error(sb, read_err_str, "backup");
719         /* We failed. Cleanup and return. */
720         if (bh_primary)
721                 brelse(bh_primary);
722         return NULL;
723 hotfix_primary_boot_sector:
724         if (bh_primary) {
725                 /*
726                  * If we managed to read sector zero and the volume is not
727                  * read-only, copy the found, valid backup boot sector to the
728                  * primary boot sector.  Note we only copy the actual boot
729                  * sector structure, not the actual whole device sector as that
730                  * may be bigger and would potentially damage the $Boot system
731                  * file (FIXME: Would be nice to know if the backup boot sector
732                  * on a large sector device contains the whole boot loader or
733                  * just the first 512 bytes).
734                  */
735                 if (!(sb->s_flags & MS_RDONLY)) {
736                         ntfs_warning(sb, "Hot-fix: Recovering invalid primary "
737                                         "boot sector from backup copy.");
738                         memcpy(bh_primary->b_data, bh_backup->b_data,
739                                         NTFS_BLOCK_SIZE);
740                         mark_buffer_dirty(bh_primary);
741                         sync_dirty_buffer(bh_primary);
742                         if (buffer_uptodate(bh_primary)) {
743                                 brelse(bh_backup);
744                                 return bh_primary;
745                         }
746                         ntfs_error(sb, "Hot-fix: Device write error while "
747                                         "recovering primary boot sector.");
748                 } else {
749                         ntfs_warning(sb, "Hot-fix: Recovery of primary boot "
750                                         "sector failed: Read-only mount.");
751                 }
752                 brelse(bh_primary);
753         }
754         ntfs_warning(sb, "Using backup boot sector.");
755         return bh_backup;
756 }
757 
758 /**
759  * parse_ntfs_boot_sector - parse the boot sector and store the data in @vol
760  * @vol:        volume structure to initialise with data from boot sector
761  * @b:          boot sector to parse
762  *
763  * Parse the ntfs boot sector @b and store all imporant information therein in
764  * the ntfs super block @vol.  Return 'true' on success and 'false' on error.
765  */
766 static bool parse_ntfs_boot_sector(ntfs_volume *vol, const NTFS_BOOT_SECTOR *b)
767 {
768         unsigned int sectors_per_cluster_bits, nr_hidden_sects;
769         int clusters_per_mft_record, clusters_per_index_record;
770         s64 ll;
771 
772         vol->sector_size = le16_to_cpu(b->bpb.bytes_per_sector);
773         vol->sector_size_bits = ffs(vol->sector_size) - 1;
774         ntfs_debug("vol->sector_size = %i (0x%x)", vol->sector_size,
775                         vol->sector_size);
776         ntfs_debug("vol->sector_size_bits = %i (0x%x)", vol->sector_size_bits,
777                         vol->sector_size_bits);
778         if (vol->sector_size < vol->sb->s_blocksize) {
779                 ntfs_error(vol->sb, "Sector size (%i) is smaller than the "
780                                 "device block size (%lu).  This is not "
781                                 "supported.  Sorry.", vol->sector_size,
782                                 vol->sb->s_blocksize);
783                 return false;
784         }
785         ntfs_debug("sectors_per_cluster = 0x%x", b->bpb.sectors_per_cluster);
786         sectors_per_cluster_bits = ffs(b->bpb.sectors_per_cluster) - 1;
787         ntfs_debug("sectors_per_cluster_bits = 0x%x",
788                         sectors_per_cluster_bits);
789         nr_hidden_sects = le32_to_cpu(b->bpb.hidden_sectors);
790         ntfs_debug("number of hidden sectors = 0x%x", nr_hidden_sects);
791         vol->cluster_size = vol->sector_size << sectors_per_cluster_bits;
792         vol->cluster_size_mask = vol->cluster_size - 1;
793         vol->cluster_size_bits = ffs(vol->cluster_size) - 1;
794         ntfs_debug("vol->cluster_size = %i (0x%x)", vol->cluster_size,
795                         vol->cluster_size);
796         ntfs_debug("vol->cluster_size_mask = 0x%x", vol->cluster_size_mask);
797         ntfs_debug("vol->cluster_size_bits = %i", vol->cluster_size_bits);
798         if (vol->cluster_size < vol->sector_size) {
799                 ntfs_error(vol->sb, "Cluster size (%i) is smaller than the "
800                                 "sector size (%i).  This is not supported.  "
801                                 "Sorry.", vol->cluster_size, vol->sector_size);
802                 return false;
803         }
804         clusters_per_mft_record = b->clusters_per_mft_record;
805         ntfs_debug("clusters_per_mft_record = %i (0x%x)",
806                         clusters_per_mft_record, clusters_per_mft_record);
807         if (clusters_per_mft_record > 0)
808                 vol->mft_record_size = vol->cluster_size <<
809                                 (ffs(clusters_per_mft_record) - 1);
810         else
811                 /*
812                  * When mft_record_size < cluster_size, clusters_per_mft_record
813                  * = -log2(mft_record_size) bytes. mft_record_size normaly is
814                  * 1024 bytes, which is encoded as 0xF6 (-10 in decimal).
815                  */
816                 vol->mft_record_size = 1 << -clusters_per_mft_record;
817         vol->mft_record_size_mask = vol->mft_record_size - 1;
818         vol->mft_record_size_bits = ffs(vol->mft_record_size) - 1;
819         ntfs_debug("vol->mft_record_size = %i (0x%x)", vol->mft_record_size,
820                         vol->mft_record_size);
821         ntfs_debug("vol->mft_record_size_mask = 0x%x",
822                         vol->mft_record_size_mask);
823         ntfs_debug("vol->mft_record_size_bits = %i (0x%x)",
824                         vol->mft_record_size_bits, vol->mft_record_size_bits);
825         /*
826          * We cannot support mft record sizes above the PAGE_CACHE_SIZE since
827          * we store $MFT/$DATA, the table of mft records in the page cache.
828          */
829         if (vol->mft_record_size > PAGE_CACHE_SIZE) {
830                 ntfs_error(vol->sb, "Mft record size (%i) exceeds the "
831                                 "PAGE_CACHE_SIZE on your system (%lu).  "
832                                 "This is not supported.  Sorry.",
833                                 vol->mft_record_size, PAGE_CACHE_SIZE);
834                 return false;
835         }
836         /* We cannot support mft record sizes below the sector size. */
837         if (vol->mft_record_size < vol->sector_size) {
838                 ntfs_error(vol->sb, "Mft record size (%i) is smaller than the "
839                                 "sector size (%i).  This is not supported.  "
840                                 "Sorry.", vol->mft_record_size,
841                                 vol->sector_size);
842                 return false;
843         }
844         clusters_per_index_record = b->clusters_per_index_record;
845         ntfs_debug("clusters_per_index_record = %i (0x%x)",
846                         clusters_per_index_record, clusters_per_index_record);
847         if (clusters_per_index_record > 0)
848                 vol->index_record_size = vol->cluster_size <<
849                                 (ffs(clusters_per_index_record) - 1);
850         else
851                 /*
852                  * When index_record_size < cluster_size,
853                  * clusters_per_index_record = -log2(index_record_size) bytes.
854                  * index_record_size normaly equals 4096 bytes, which is
855                  * encoded as 0xF4 (-12 in decimal).
856                  */
857                 vol->index_record_size = 1 << -clusters_per_index_record;
858         vol->index_record_size_mask = vol->index_record_size - 1;
859         vol->index_record_size_bits = ffs(vol->index_record_size) - 1;
860         ntfs_debug("vol->index_record_size = %i (0x%x)",
861                         vol->index_record_size, vol->index_record_size);
862         ntfs_debug("vol->index_record_size_mask = 0x%x",
863                         vol->index_record_size_mask);
864         ntfs_debug("vol->index_record_size_bits = %i (0x%x)",
865                         vol->index_record_size_bits,
866                         vol->index_record_size_bits);
867         /* We cannot support index record sizes below the sector size. */
868         if (vol->index_record_size < vol->sector_size) {
869                 ntfs_error(vol->sb, "Index record size (%i) is smaller than "
870                                 "the sector size (%i).  This is not "
871                                 "supported.  Sorry.", vol->index_record_size,
872                                 vol->sector_size);
873                 return false;
874         }
875         /*
876          * Get the size of the volume in clusters and check for 64-bit-ness.
877          * Windows currently only uses 32 bits to save the clusters so we do
878          * the same as it is much faster on 32-bit CPUs.
879          */
880         ll = sle64_to_cpu(b->number_of_sectors) >> sectors_per_cluster_bits;
881         if ((u64)ll >= 1ULL << 32) {
882                 ntfs_error(vol->sb, "Cannot handle 64-bit clusters.  Sorry.");
883                 return false;
884         }
885         vol->nr_clusters = ll;
886         ntfs_debug("vol->nr_clusters = 0x%llx", (long long)vol->nr_clusters);
887         /*
888          * On an architecture where unsigned long is 32-bits, we restrict the
889          * volume size to 2TiB (2^41). On a 64-bit architecture, the compiler
890          * will hopefully optimize the whole check away.
891          */
892         if (sizeof(unsigned long) < 8) {
893                 if ((ll << vol->cluster_size_bits) >= (1ULL << 41)) {
894                         ntfs_error(vol->sb, "Volume size (%lluTiB) is too "
895                                         "large for this architecture.  "
896                                         "Maximum supported is 2TiB.  Sorry.",
897                                         (unsigned long long)ll >> (40 -
898                                         vol->cluster_size_bits));
899                         return false;
900                 }
901         }
902         ll = sle64_to_cpu(b->mft_lcn);
903         if (ll >= vol->nr_clusters) {
904                 ntfs_error(vol->sb, "MFT LCN (%lli, 0x%llx) is beyond end of "
905                                 "volume.  Weird.", (unsigned long long)ll,
906                                 (unsigned long long)ll);
907                 return false;
908         }
909         vol->mft_lcn = ll;
910         ntfs_debug("vol->mft_lcn = 0x%llx", (long long)vol->mft_lcn);
911         ll = sle64_to_cpu(b->mftmirr_lcn);
912         if (ll >= vol->nr_clusters) {
913                 ntfs_error(vol->sb, "MFTMirr LCN (%lli, 0x%llx) is beyond end "
914                                 "of volume.  Weird.", (unsigned long long)ll,
915                                 (unsigned long long)ll);
916                 return false;
917         }
918         vol->mftmirr_lcn = ll;
919         ntfs_debug("vol->mftmirr_lcn = 0x%llx", (long long)vol->mftmirr_lcn);
920 #ifdef NTFS_RW
921         /*
922          * Work out the size of the mft mirror in number of mft records. If the
923          * cluster size is less than or equal to the size taken by four mft
924          * records, the mft mirror stores the first four mft records. If the
925          * cluster size is bigger than the size taken by four mft records, the
926          * mft mirror contains as many mft records as will fit into one
927          * cluster.
928          */
929         if (vol->cluster_size <= (4 << vol->mft_record_size_bits))
930                 vol->mftmirr_size = 4;
931         else
932                 vol->mftmirr_size = vol->cluster_size >>
933                                 vol->mft_record_size_bits;
934         ntfs_debug("vol->mftmirr_size = %i", vol->mftmirr_size);
935 #endif /* NTFS_RW */
936         vol->serial_no = le64_to_cpu(b->volume_serial_number);
937         ntfs_debug("vol->serial_no = 0x%llx",
938                         (unsigned long long)vol->serial_no);
939         return true;
940 }
941 
942 /**
943  * ntfs_setup_allocators - initialize the cluster and mft allocators
944  * @vol:        volume structure for which to setup the allocators
945  *
946  * Setup the cluster (lcn) and mft allocators to the starting values.
947  */
948 static void ntfs_setup_allocators(ntfs_volume *vol)
949 {
950 #ifdef NTFS_RW
951         LCN mft_zone_size, mft_lcn;
952 #endif /* NTFS_RW */
953 
954         ntfs_debug("vol->mft_zone_multiplier = 0x%x",
955                         vol->mft_zone_multiplier);
956 #ifdef NTFS_RW
957         /* Determine the size of the MFT zone. */
958         mft_zone_size = vol->nr_clusters;
959         switch (vol->mft_zone_multiplier) {  /* % of volume size in clusters */
960         case 4:
961                 mft_zone_size >>= 1;                    /* 50%   */
962                 break;
963         case 3:
964                 mft_zone_size = (mft_zone_size +
965                                 (mft_zone_size >> 1)) >> 2;     /* 37.5% */
966                 break;
967         case 2:
968                 mft_zone_size >>= 2;                    /* 25%   */
969                 break;
970         /* case 1: */
971         default:
972                 mft_zone_size >>= 3;                    /* 12.5% */
973                 break;
974         }
975         /* Setup the mft zone. */
976         vol->mft_zone_start = vol->mft_zone_pos = vol->mft_lcn;
977         ntfs_debug("vol->mft_zone_pos = 0x%llx",
978                         (unsigned long long)vol->mft_zone_pos);
979         /*
980          * Calculate the mft_lcn for an unmodified NTFS volume (see mkntfs
981          * source) and if the actual mft_lcn is in the expected place or even
982          * further to the front of the volume, extend the mft_zone to cover the
983          * beginning of the volume as well.  This is in order to protect the
984          * area reserved for the mft bitmap as well within the mft_zone itself.
985          * On non-standard volumes we do not protect it as the overhead would
986          * be higher than the speed increase we would get by doing it.
987          */
988         mft_lcn = (8192 + 2 * vol->cluster_size - 1) / vol->cluster_size;
989         if (mft_lcn * vol->cluster_size < 16 * 1024)
990                 mft_lcn = (16 * 1024 + vol->cluster_size - 1) /
991                                 vol->cluster_size;
992         if (vol->mft_zone_start <= mft_lcn)
993                 vol->mft_zone_start = 0;
994         ntfs_debug("vol->mft_zone_start = 0x%llx",
995                         (unsigned long long)vol->mft_zone_start);
996         /*
997          * Need to cap the mft zone on non-standard volumes so that it does
998          * not point outside the boundaries of the volume.  We do this by
999          * halving the zone size until we are inside the volume.
1000          */
1001         vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
1002         while (vol->mft_zone_end >= vol->nr_clusters) {
1003                 mft_zone_size >>= 1;
1004                 vol->mft_zone_end = vol->mft_lcn + mft_zone_size;
1005         }
1006         ntfs_debug("vol->mft_zone_end = 0x%llx",
1007                         (unsigned long long)vol->mft_zone_end);
1008         /*
1009          * Set the current position within each data zone to the start of the
1010          * respective zone.
1011          */
1012         vol->data1_zone_pos = vol->mft_zone_end;
1013         ntfs_debug("vol->data1_zone_pos = 0x%llx",
1014                         (unsigned long long)vol->data1_zone_pos);
1015         vol->data2_zone_pos = 0;
1016         ntfs_debug("vol->data2_zone_pos = 0x%llx",
1017                         (unsigned long long)vol->data2_zone_pos);
1018 
1019         /* Set the mft data allocation position to mft record 24. */
1020         vol->mft_data_pos = 24;
1021         ntfs_debug("vol->mft_data_pos = 0x%llx",
1022                         (unsigned long long)vol->mft_data_pos);
1023 #endif /* NTFS_RW */
1024 }
1025 
1026 #ifdef NTFS_RW
1027 
1028 /**
1029  * load_and_init_mft_mirror - load and setup the mft mirror inode for a volume
1030  * @vol:        ntfs super block describing device whose mft mirror to load
1031  *
1032  * Return 'true' on success or 'false' on error.
1033  */
1034 static bool load_and_init_mft_mirror(ntfs_volume *vol)
1035 {
1036         struct inode *tmp_ino;
1037         ntfs_inode *tmp_ni;
1038 
1039         ntfs_debug("Entering.");
1040         /* Get mft mirror inode. */
1041         tmp_ino = ntfs_iget(vol->sb, FILE_MFTMirr);
1042         if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
1043                 if (!IS_ERR(tmp_ino))
1044                         iput(tmp_ino);
1045                 /* Caller will display error message. */
1046                 return false;
1047         }
1048         /*
1049          * Re-initialize some specifics about $MFTMirr's inode as
1050          * ntfs_read_inode() will have set up the default ones.
1051          */
1052         /* Set uid and gid to root. */
1053         tmp_ino->i_uid = GLOBAL_ROOT_UID;
1054         tmp_ino->i_gid = GLOBAL_ROOT_GID;
1055         /* Regular file.  No access for anyone. */
1056         tmp_ino->i_mode = S_IFREG;
1057         /* No VFS initiated operations allowed for $MFTMirr. */
1058         tmp_ino->i_op = &ntfs_empty_inode_ops;
1059         tmp_ino->i_fop = &ntfs_empty_file_ops;
1060         /* Put in our special address space operations. */
1061         tmp_ino->i_mapping->a_ops = &ntfs_mst_aops;
1062         tmp_ni = NTFS_I(tmp_ino);
1063         /* The $MFTMirr, like the $MFT is multi sector transfer protected. */
1064         NInoSetMstProtected(tmp_ni);
1065         NInoSetSparseDisabled(tmp_ni);
1066         /*
1067          * Set up our little cheat allowing us to reuse the async read io
1068          * completion handler for directories.
1069          */
1070         tmp_ni->itype.index.block_size = vol->mft_record_size;
1071         tmp_ni->itype.index.block_size_bits = vol->mft_record_size_bits;
1072         vol->mftmirr_ino = tmp_ino;
1073         ntfs_debug("Done.");
1074         return true;
1075 }
1076 
1077 /**
1078  * check_mft_mirror - compare contents of the mft mirror with the mft
1079  * @vol:        ntfs super block describing device whose mft mirror to check
1080  *
1081  * Return 'true' on success or 'false' on error.
1082  *
1083  * Note, this function also results in the mft mirror runlist being completely
1084  * mapped into memory.  The mft mirror write code requires this and will BUG()
1085  * should it find an unmapped runlist element.
1086  */
1087 static bool check_mft_mirror(ntfs_volume *vol)
1088 {
1089         struct super_block *sb = vol->sb;
1090         ntfs_inode *mirr_ni;
1091         struct page *mft_page, *mirr_page;
1092         u8 *kmft, *kmirr;
1093         runlist_element *rl, rl2[2];
1094         pgoff_t index;
1095         int mrecs_per_page, i;
1096 
1097         ntfs_debug("Entering.");
1098         /* Compare contents of $MFT and $MFTMirr. */
1099         mrecs_per_page = PAGE_CACHE_SIZE / vol->mft_record_size;
1100         BUG_ON(!mrecs_per_page);
1101         BUG_ON(!vol->mftmirr_size);
1102         mft_page = mirr_page = NULL;
1103         kmft = kmirr = NULL;
1104         index = i = 0;
1105         do {
1106                 u32 bytes;
1107 
1108                 /* Switch pages if necessary. */
1109                 if (!(i % mrecs_per_page)) {
1110                         if (index) {
1111                                 ntfs_unmap_page(mft_page);
1112                                 ntfs_unmap_page(mirr_page);
1113                         }
1114                         /* Get the $MFT page. */
1115                         mft_page = ntfs_map_page(vol->mft_ino->i_mapping,
1116                                         index);
1117                         if (IS_ERR(mft_page)) {
1118                                 ntfs_error(sb, "Failed to read $MFT.");
1119                                 return false;
1120                         }
1121                         kmft = page_address(mft_page);
1122                         /* Get the $MFTMirr page. */
1123                         mirr_page = ntfs_map_page(vol->mftmirr_ino->i_mapping,
1124                                         index);
1125                         if (IS_ERR(mirr_page)) {
1126                                 ntfs_error(sb, "Failed to read $MFTMirr.");
1127                                 goto mft_unmap_out;
1128                         }
1129                         kmirr = page_address(mirr_page);
1130                         ++index;
1131                 }
1132                 /* Do not check the record if it is not in use. */
1133                 if (((MFT_RECORD*)kmft)->flags & MFT_RECORD_IN_USE) {
1134                         /* Make sure the record is ok. */
1135                         if (ntfs_is_baad_recordp((le32*)kmft)) {
1136                                 ntfs_error(sb, "Incomplete multi sector "
1137                                                 "transfer detected in mft "
1138                                                 "record %i.", i);
1139 mm_unmap_out:
1140                                 ntfs_unmap_page(mirr_page);
1141 mft_unmap_out:
1142                                 ntfs_unmap_page(mft_page);
1143                                 return false;
1144                         }
1145                 }
1146                 /* Do not check the mirror record if it is not in use. */
1147                 if (((MFT_RECORD*)kmirr)->flags & MFT_RECORD_IN_USE) {
1148                         if (ntfs_is_baad_recordp((le32*)kmirr)) {
1149                                 ntfs_error(sb, "Incomplete multi sector "
1150                                                 "transfer detected in mft "
1151                                                 "mirror record %i.", i);
1152                                 goto mm_unmap_out;
1153                         }
1154                 }
1155                 /* Get the amount of data in the current record. */
1156                 bytes = le32_to_cpu(((MFT_RECORD*)kmft)->bytes_in_use);
1157                 if (bytes < sizeof(MFT_RECORD_OLD) ||
1158                                 bytes > vol->mft_record_size ||
1159                                 ntfs_is_baad_recordp((le32*)kmft)) {
1160                         bytes = le32_to_cpu(((MFT_RECORD*)kmirr)->bytes_in_use);
1161                         if (bytes < sizeof(MFT_RECORD_OLD) ||
1162                                         bytes > vol->mft_record_size ||
1163                                         ntfs_is_baad_recordp((le32*)kmirr))
1164                                 bytes = vol->mft_record_size;
1165                 }
1166                 /* Compare the two records. */
1167                 if (memcmp(kmft, kmirr, bytes)) {
1168                         ntfs_error(sb, "$MFT and $MFTMirr (record %i) do not "
1169                                         "match.  Run ntfsfix or chkdsk.", i);
1170                         goto mm_unmap_out;
1171                 }
1172                 kmft += vol->mft_record_size;
1173                 kmirr += vol->mft_record_size;
1174         } while (++i < vol->mftmirr_size);
1175         /* Release the last pages. */
1176         ntfs_unmap_page(mft_page);
1177         ntfs_unmap_page(mirr_page);
1178 
1179         /* Construct the mft mirror runlist by hand. */
1180         rl2[0].vcn = 0;
1181         rl2[0].lcn = vol->mftmirr_lcn;
1182         rl2[0].length = (vol->mftmirr_size * vol->mft_record_size +
1183                         vol->cluster_size - 1) / vol->cluster_size;
1184         rl2[1].vcn = rl2[0].length;
1185         rl2[1].lcn = LCN_ENOENT;
1186         rl2[1].length = 0;
1187         /*
1188          * Because we have just read all of the mft mirror, we know we have
1189          * mapped the full runlist for it.
1190          */
1191         mirr_ni = NTFS_I(vol->mftmirr_ino);
1192         down_read(&mirr_ni->runlist.lock);
1193         rl = mirr_ni->runlist.rl;
1194         /* Compare the two runlists.  They must be identical. */
1195         i = 0;
1196         do {
1197                 if (rl2[i].vcn != rl[i].vcn || rl2[i].lcn != rl[i].lcn ||
1198                                 rl2[i].length != rl[i].length) {
1199                         ntfs_error(sb, "$MFTMirr location mismatch.  "
1200                                         "Run chkdsk.");
1201                         up_read(&mirr_ni->runlist.lock);
1202                         return false;
1203                 }
1204         } while (rl2[i++].length);
1205         up_read(&mirr_ni->runlist.lock);
1206         ntfs_debug("Done.");
1207         return true;
1208 }
1209 
1210 /**
1211  * load_and_check_logfile - load and check the logfile inode for a volume
1212  * @vol:        ntfs super block describing device whose logfile to load
1213  *
1214  * Return 'true' on success or 'false' on error.
1215  */
1216 static bool load_and_check_logfile(ntfs_volume *vol,
1217                 RESTART_PAGE_HEADER **rp)
1218 {
1219         struct inode *tmp_ino;
1220 
1221         ntfs_debug("Entering.");
1222         tmp_ino = ntfs_iget(vol->sb, FILE_LogFile);
1223         if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
1224                 if (!IS_ERR(tmp_ino))
1225                         iput(tmp_ino);
1226                 /* Caller will display error message. */
1227                 return false;
1228         }
1229         if (!ntfs_check_logfile(tmp_ino, rp)) {
1230                 iput(tmp_ino);
1231                 /* ntfs_check_logfile() will have displayed error output. */
1232                 return false;
1233         }
1234         NInoSetSparseDisabled(NTFS_I(tmp_ino));
1235         vol->logfile_ino = tmp_ino;
1236         ntfs_debug("Done.");
1237         return true;
1238 }
1239 
1240 #define NTFS_HIBERFIL_HEADER_SIZE       4096
1241 
1242 /**
1243  * check_windows_hibernation_status - check if Windows is suspended on a volume
1244  * @vol:        ntfs super block of device to check
1245  *
1246  * Check if Windows is hibernated on the ntfs volume @vol.  This is done by
1247  * looking for the file hiberfil.sys in the root directory of the volume.  If
1248  * the file is not present Windows is definitely not suspended.
1249  *
1250  * If hiberfil.sys exists and is less than 4kiB in size it means Windows is
1251  * definitely suspended (this volume is not the system volume).  Caveat:  on a
1252  * system with many volumes it is possible that the < 4kiB check is bogus but
1253  * for now this should do fine.
1254  *
1255  * If hiberfil.sys exists and is larger than 4kiB in size, we need to read the
1256  * hiberfil header (which is the first 4kiB).  If this begins with "hibr",
1257  * Windows is definitely suspended.  If it is completely full of zeroes,
1258  * Windows is definitely not hibernated.  Any other case is treated as if
1259  * Windows is suspended.  This caters for the above mentioned caveat of a
1260  * system with many volumes where no "hibr" magic would be present and there is
1261  * no zero header.
1262  *
1263  * Return 0 if Windows is not hibernated on the volume, >0 if Windows is
1264  * hibernated on the volume, and -errno on error.
1265  */
1266 static int check_windows_hibernation_status(ntfs_volume *vol)
1267 {
1268         MFT_REF mref;
1269         struct inode *vi;
1270         struct page *page;
1271         u32 *kaddr, *kend;
1272         ntfs_name *name = NULL;
1273         int ret = 1;
1274         static const ntfschar hiberfil[13] = { cpu_to_le16('h'),
1275                         cpu_to_le16('i'), cpu_to_le16('b'),
1276                         cpu_to_le16('e'), cpu_to_le16('r'),
1277                         cpu_to_le16('f'), cpu_to_le16('i'),
1278                         cpu_to_le16('l'), cpu_to_le16('.'),
1279                         cpu_to_le16('s'), cpu_to_le16('y'),
1280                         cpu_to_le16('s'), 0 };
1281 
1282         ntfs_debug("Entering.");
1283         /*
1284          * Find the inode number for the hibernation file by looking up the
1285          * filename hiberfil.sys in the root directory.
1286          */
1287         mutex_lock(&vol->root_ino->i_mutex);
1288         mref = ntfs_lookup_inode_by_name(NTFS_I(vol->root_ino), hiberfil, 12,
1289                         &name);
1290         mutex_unlock(&vol->root_ino->i_mutex);
1291         if (IS_ERR_MREF(mref)) {
1292                 ret = MREF_ERR(mref);
1293                 /* If the file does not exist, Windows is not hibernated. */
1294                 if (ret == -ENOENT) {
1295                         ntfs_debug("hiberfil.sys not present.  Windows is not "
1296                                         "hibernated on the volume.");
1297                         return 0;
1298                 }
1299                 /* A real error occurred. */
1300                 ntfs_error(vol->sb, "Failed to find inode number for "
1301                                 "hiberfil.sys.");
1302                 return ret;
1303         }
1304         /* We do not care for the type of match that was found. */
1305         kfree(name);
1306         /* Get the inode. */
1307         vi = ntfs_iget(vol->sb, MREF(mref));
1308         if (IS_ERR(vi) || is_bad_inode(vi)) {
1309                 if (!IS_ERR(vi))
1310                         iput(vi);
1311                 ntfs_error(vol->sb, "Failed to load hiberfil.sys.");
1312                 return IS_ERR(vi) ? PTR_ERR(vi) : -EIO;
1313         }
1314         if (unlikely(i_size_read(vi) < NTFS_HIBERFIL_HEADER_SIZE)) {
1315                 ntfs_debug("hiberfil.sys is smaller than 4kiB (0x%llx).  "
1316                                 "Windows is hibernated on the volume.  This "
1317                                 "is not the system volume.", i_size_read(vi));
1318                 goto iput_out;
1319         }
1320         page = ntfs_map_page(vi->i_mapping, 0);
1321         if (IS_ERR(page)) {
1322                 ntfs_error(vol->sb, "Failed to read from hiberfil.sys.");
1323                 ret = PTR_ERR(page);
1324                 goto iput_out;
1325         }
1326         kaddr = (u32*)page_address(page);
1327         if (*(le32*)kaddr == cpu_to_le32(0x72626968)/*'hibr'*/) {
1328                 ntfs_debug("Magic \"hibr\" found in hiberfil.sys.  Windows is "
1329                                 "hibernated on the volume.  This is the "
1330                                 "system volume.");
1331                 goto unm_iput_out;
1332         }
1333         kend = kaddr + NTFS_HIBERFIL_HEADER_SIZE/sizeof(*kaddr);
1334         do {
1335                 if (unlikely(*kaddr)) {
1336                         ntfs_debug("hiberfil.sys is larger than 4kiB "
1337                                         "(0x%llx), does not contain the "
1338                                         "\"hibr\" magic, and does not have a "
1339                                         "zero header.  Windows is hibernated "
1340                                         "on the volume.  This is not the "
1341                                         "system volume.", i_size_read(vi));
1342                         goto unm_iput_out;
1343                 }
1344         } while (++kaddr < kend);
1345         ntfs_debug("hiberfil.sys contains a zero header.  Windows is not "
1346                         "hibernated on the volume.  This is the system "
1347                         "volume.");
1348         ret = 0;
1349 unm_iput_out:
1350         ntfs_unmap_page(page);
1351 iput_out:
1352         iput(vi);
1353         return ret;
1354 }
1355 
1356 /**
1357  * load_and_init_quota - load and setup the quota file for a volume if present
1358  * @vol:        ntfs super block describing device whose quota file to load
1359  *
1360  * Return 'true' on success or 'false' on error.  If $Quota is not present, we
1361  * leave vol->quota_ino as NULL and return success.
1362  */
1363 static bool load_and_init_quota(ntfs_volume *vol)
1364 {
1365         MFT_REF mref;
1366         struct inode *tmp_ino;
1367         ntfs_name *name = NULL;
1368         static const ntfschar Quota[7] = { cpu_to_le16('$'),
1369                         cpu_to_le16('Q'), cpu_to_le16('u'),
1370                         cpu_to_le16('o'), cpu_to_le16('t'),
1371                         cpu_to_le16('a'), 0 };
1372         static ntfschar Q[3] = { cpu_to_le16('$'),
1373                         cpu_to_le16('Q'), 0 };
1374 
1375         ntfs_debug("Entering.");
1376         /*
1377          * Find the inode number for the quota file by looking up the filename
1378          * $Quota in the extended system files directory $Extend.
1379          */
1380         mutex_lock(&vol->extend_ino->i_mutex);
1381         mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), Quota, 6,
1382                         &name);
1383         mutex_unlock(&vol->extend_ino->i_mutex);
1384         if (IS_ERR_MREF(mref)) {
1385                 /*
1386                  * If the file does not exist, quotas are disabled and have
1387                  * never been enabled on this volume, just return success.
1388                  */
1389                 if (MREF_ERR(mref) == -ENOENT) {
1390                         ntfs_debug("$Quota not present.  Volume does not have "
1391                                         "quotas enabled.");
1392                         /*
1393                          * No need to try to set quotas out of date if they are
1394                          * not enabled.
1395                          */
1396                         NVolSetQuotaOutOfDate(vol);
1397                         return true;
1398                 }
1399                 /* A real error occurred. */
1400                 ntfs_error(vol->sb, "Failed to find inode number for $Quota.");
1401                 return false;
1402         }
1403         /* We do not care for the type of match that was found. */
1404         kfree(name);
1405         /* Get the inode. */
1406         tmp_ino = ntfs_iget(vol->sb, MREF(mref));
1407         if (IS_ERR(tmp_ino) || is_bad_inode(tmp_ino)) {
1408                 if (!IS_ERR(tmp_ino))
1409                         iput(tmp_ino);
1410                 ntfs_error(vol->sb, "Failed to load $Quota.");
1411                 return false;
1412         }
1413         vol->quota_ino = tmp_ino;
1414         /* Get the $Q index allocation attribute. */
1415         tmp_ino = ntfs_index_iget(vol->quota_ino, Q, 2);
1416         if (IS_ERR(tmp_ino)) {
1417                 ntfs_error(vol->sb, "Failed to load $Quota/$Q index.");
1418                 return false;
1419         }
1420         vol->quota_q_ino = tmp_ino;
1421         ntfs_debug("Done.");
1422         return true;
1423 }
1424 
1425 /**
1426  * load_and_init_usnjrnl - load and setup the transaction log if present
1427  * @vol:        ntfs super block describing device whose usnjrnl file to load
1428  *
1429  * Return 'true' on success or 'false' on error.
1430  *
1431  * If $UsnJrnl is not present or in the process of being disabled, we set
1432  * NVolUsnJrnlStamped() and return success.
1433  *
1434  * If the $UsnJrnl $DATA/$J attribute has a size equal to the lowest valid usn,
1435  * i.e. transaction logging has only just been enabled or the journal has been
1436  * stamped and nothing has been logged since, we also set NVolUsnJrnlStamped()
1437  * and return success.
1438  */
1439 static bool load_and_init_usnjrnl(ntfs_volume *vol)
1440 {
1441         MFT_REF mref;
1442         struct inode *tmp_ino;
1443         ntfs_inode *tmp_ni;
1444         struct page *page;
1445         ntfs_name *name = NULL;
1446         USN_HEADER *uh;
1447         static const ntfschar UsnJrnl[9] = { cpu_to_le16('$'),
1448                         cpu_to_le16('U'), cpu_to_le16('s'),
1449                         cpu_to_le16('n'), cpu_to_le16('J'),
1450                         cpu_to_le16('r'), cpu_to_le16('n'),
1451                         cpu_to_le16('l'), 0 };
1452         static ntfschar Max[5] = { cpu_to_le16('$'),
1453                         cpu_to_le16('M'), cpu_to_le16('a'),
1454                         cpu_to_le16('x'), 0 };
1455         static ntfschar J[3] = { cpu_to_le16('$'),
1456                         cpu_to_le16('J'), 0 };
1457 
1458         ntfs_debug("Entering.");
1459         /*
1460          * Find the inode number for the transaction log file by looking up the
1461          * filename $UsnJrnl in the extended system files directory $Extend.
1462          */
1463         mutex_lock(&vol->extend_ino->i_mutex);
1464         mref = ntfs_lookup_inode_by_name(NTFS_I(vol->extend_ino), UsnJrnl, 8,
1465                         &name);
1466         mutex_unlock(&vol->extend_ino->i_mutex);
1467         if (IS_ERR_MREF(mref)) {
1468                 /*
1469                  * If the file does not exist, transaction logging is disabled,
1470                  * just return success.
1471                  */
1472                 if (MREF_ERR(mref) == -ENOENT) {
1473                         ntfs_debug("$UsnJrnl not present.  Volume does not "
1474                                         "have transaction logging enabled.");
1475 not_enabled:
1476                         /*
1477                          * No need to try to stamp the transaction log if
1478                          * transaction logging is not enabled.
1479                          */
1480                         NVolSetUsnJrnlStamped(vol);
1481                         return true;
1482                 }
1483                 /* A real error occurred. */
1484                 ntfs_error(vol->sb, "Failed to find inode number for "
1485                                 "$UsnJrnl.");
1486                 return false;
1487         }
1488         /* We do not care for the type of match that was found. */
1489         kfree(name);
1490         /* Get the inode. */
1491         tmp_ino = ntfs_iget(vol->sb, MREF(mref));
1492         if (unlikely(IS_ERR(tmp_ino) || is_bad_inode(tmp_ino))) {
1493                 if (!IS_ERR(tmp_ino))
1494                         iput(tmp_ino);
1495                 ntfs_error(vol->sb, "Failed to load $UsnJrnl.");
1496                 return false;
1497         }
1498         vol->usnjrnl_ino = tmp_ino;
1499         /*
1500          * If the transaction log is in the process of being deleted, we can
1501          * ignore it.
1502          */
1503         if (unlikely(vol->vol_flags & VOLUME_DELETE_USN_UNDERWAY)) {
1504                 ntfs_debug("$UsnJrnl in the process of being disabled.  "
1505                                 "Volume does not have transaction logging "
1506                                 "enabled.");
1507                 goto not_enabled;
1508         }
1509         /* Get the $DATA/$Max attribute. */
1510         tmp_ino = ntfs_attr_iget(vol->usnjrnl_ino, AT_DATA, Max, 4);
1511         if (IS_ERR(tmp_ino)) {
1512                 ntfs_error(vol->sb, "Failed to load $UsnJrnl/$DATA/$Max "
1513                                 "attribute.");
1514                 return false;
1515         }
1516         vol->usnjrnl_max_ino = tmp_ino;
1517         if (unlikely(i_size_read(tmp_ino) < sizeof(USN_HEADER))) {
1518                 ntfs_error(vol->sb, "Found corrupt $UsnJrnl/$DATA/$Max "
1519                                 "attribute (size is 0x%llx but should be at "
1520                                 "least 0x%zx bytes).", i_size_read(tmp_ino),
1521                                 sizeof(USN_HEADER));
1522                 return false;
1523         }
1524         /* Get the $DATA/$J attribute. */
1525         tmp_ino = ntfs_attr_iget(vol->usnjrnl_ino, AT_DATA, J, 2);
1526         if (IS_ERR(tmp_ino)) {
1527                 ntfs_error(vol->sb, "Failed to load $UsnJrnl/$DATA/$J "
1528                                 "attribute.");
1529                 return false;
1530         }
1531         vol->usnjrnl_j_ino = tmp_ino;
1532         /* Verify $J is non-resident and sparse. */
1533         tmp_ni = NTFS_I(vol->usnjrnl_j_ino);
1534         if (unlikely(!NInoNonResident(tmp_ni) || !NInoSparse(tmp_ni))) {
1535                 ntfs_error(vol->sb, "$UsnJrnl/$DATA/$J attribute is resident "
1536                                 "and/or not sparse.");
1537                 return false;
1538         }
1539         /* Read the USN_HEADER from $DATA/$Max. */
1540         page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
1541         if (IS_ERR(page)) {
1542                 ntfs_error(vol->sb, "Failed to read from $UsnJrnl/$DATA/$Max "
1543                                 "attribute.");
1544                 return false;
1545         }
1546         uh = (USN_HEADER*)page_address(page);
1547         /* Sanity check the $Max. */
1548         if (unlikely(sle64_to_cpu(uh->allocation_delta) >
1549                         sle64_to_cpu(uh->maximum_size))) {
1550                 ntfs_error(vol->sb, "Allocation delta (0x%llx) exceeds "
1551                                 "maximum size (0x%llx).  $UsnJrnl is corrupt.",
1552                                 (long long)sle64_to_cpu(uh->allocation_delta),
1553                                 (long long)sle64_to_cpu(uh->maximum_size));
1554                 ntfs_unmap_page(page);
1555                 return false;
1556         }
1557         /*
1558          * If the transaction log has been stamped and nothing has been written
1559          * to it since, we do not need to stamp it.
1560          */
1561         if (unlikely(sle64_to_cpu(uh->lowest_valid_usn) >=
1562                         i_size_read(vol->usnjrnl_j_ino))) {
1563                 if (likely(sle64_to_cpu(uh->lowest_valid_usn) ==
1564                                 i_size_read(vol->usnjrnl_j_ino))) {
1565                         ntfs_unmap_page(page);
1566                         ntfs_debug("$UsnJrnl is enabled but nothing has been "
1567                                         "logged since it was last stamped.  "
1568                                         "Treating this as if the volume does "
1569                                         "not have transaction logging "
1570                                         "enabled.");
1571                         goto not_enabled;
1572                 }
1573                 ntfs_error(vol->sb, "$UsnJrnl has lowest valid usn (0x%llx) "
1574                                 "which is out of bounds (0x%llx).  $UsnJrnl "
1575                                 "is corrupt.",
1576                                 (long long)sle64_to_cpu(uh->lowest_valid_usn),
1577                                 i_size_read(vol->usnjrnl_j_ino));
1578                 ntfs_unmap_page(page);
1579                 return false;
1580         }
1581         ntfs_unmap_page(page);
1582         ntfs_debug("Done.");
1583         return true;
1584 }
1585 
1586 /**
1587  * load_and_init_attrdef - load the attribute definitions table for a volume
1588  * @vol:        ntfs super block describing device whose attrdef to load
1589  *
1590  * Return 'true' on success or 'false' on error.
1591  */
1592 static bool load_and_init_attrdef(ntfs_volume *vol)
1593 {
1594         loff_t i_size;
1595         struct super_block *sb = vol->sb;
1596         struct inode *ino;
1597         struct page *page;
1598         pgoff_t index, max_index;
1599         unsigned int size;
1600 
1601         ntfs_debug("Entering.");
1602         /* Read attrdef table and setup vol->attrdef and vol->attrdef_size. */
1603         ino = ntfs_iget(sb, FILE_AttrDef);
1604         if (IS_ERR(ino) || is_bad_inode(ino)) {
1605                 if (!IS_ERR(ino))
1606                         iput(ino);
1607                 goto failed;
1608         }
1609         NInoSetSparseDisabled(NTFS_I(ino));
1610         /* The size of FILE_AttrDef must be above 0 and fit inside 31 bits. */
1611         i_size = i_size_read(ino);
1612         if (i_size <= 0 || i_size > 0x7fffffff)
1613                 goto iput_failed;
1614         vol->attrdef = (ATTR_DEF*)ntfs_malloc_nofs(i_size);
1615         if (!vol->attrdef)
1616                 goto iput_failed;
1617         index = 0;
1618         max_index = i_size >> PAGE_CACHE_SHIFT;
1619         size = PAGE_CACHE_SIZE;
1620         while (index < max_index) {
1621                 /* Read the attrdef table and copy it into the linear buffer. */
1622 read_partial_attrdef_page:
1623                 page = ntfs_map_page(ino->i_mapping, index);
1624                 if (IS_ERR(page))
1625                         goto free_iput_failed;
1626                 memcpy((u8*)vol->attrdef + (index++ << PAGE_CACHE_SHIFT),
1627                                 page_address(page), size);
1628                 ntfs_unmap_page(page);
1629         };
1630         if (size == PAGE_CACHE_SIZE) {
1631                 size = i_size & ~PAGE_CACHE_MASK;
1632                 if (size)
1633                         goto read_partial_attrdef_page;
1634         }
1635         vol->attrdef_size = i_size;
1636         ntfs_debug("Read %llu bytes from $AttrDef.", i_size);
1637         iput(ino);
1638         return true;
1639 free_iput_failed:
1640         ntfs_free(vol->attrdef);
1641         vol->attrdef = NULL;
1642 iput_failed:
1643         iput(ino);
1644 failed:
1645         ntfs_error(sb, "Failed to initialize attribute definition table.");
1646         return false;
1647 }
1648 
1649 #endif /* NTFS_RW */
1650 
1651 /**
1652  * load_and_init_upcase - load the upcase table for an ntfs volume
1653  * @vol:        ntfs super block describing device whose upcase to load
1654  *
1655  * Return 'true' on success or 'false' on error.
1656  */
1657 static bool load_and_init_upcase(ntfs_volume *vol)
1658 {
1659         loff_t i_size;
1660         struct super_block *sb = vol->sb;
1661         struct inode *ino;
1662         struct page *page;
1663         pgoff_t index, max_index;
1664         unsigned int size;
1665         int i, max;
1666 
1667         ntfs_debug("Entering.");
1668         /* Read upcase table and setup vol->upcase and vol->upcase_len. */
1669         ino = ntfs_iget(sb, FILE_UpCase);
1670         if (IS_ERR(ino) || is_bad_inode(ino)) {
1671                 if (!IS_ERR(ino))
1672                         iput(ino);
1673                 goto upcase_failed;
1674         }
1675         /*
1676          * The upcase size must not be above 64k Unicode characters, must not
1677          * be zero and must be a multiple of sizeof(ntfschar).
1678          */
1679         i_size = i_size_read(ino);
1680         if (!i_size || i_size & (sizeof(ntfschar) - 1) ||
1681                         i_size > 64ULL * 1024 * sizeof(ntfschar))
1682                 goto iput_upcase_failed;
1683         vol->upcase = (ntfschar*)ntfs_malloc_nofs(i_size);
1684         if (!vol->upcase)
1685                 goto iput_upcase_failed;
1686         index = 0;
1687         max_index = i_size >> PAGE_CACHE_SHIFT;
1688         size = PAGE_CACHE_SIZE;
1689         while (index < max_index) {
1690                 /* Read the upcase table and copy it into the linear buffer. */
1691 read_partial_upcase_page:
1692                 page = ntfs_map_page(ino->i_mapping, index);
1693                 if (IS_ERR(page))
1694                         goto iput_upcase_failed;
1695                 memcpy((char*)vol->upcase + (index++ << PAGE_CACHE_SHIFT),
1696                                 page_address(page), size);
1697                 ntfs_unmap_page(page);
1698         };
1699         if (size == PAGE_CACHE_SIZE) {
1700                 size = i_size & ~PAGE_CACHE_MASK;
1701                 if (size)
1702                         goto read_partial_upcase_page;
1703         }
1704         vol->upcase_len = i_size >> UCHAR_T_SIZE_BITS;
1705         ntfs_debug("Read %llu bytes from $UpCase (expected %zu bytes).",
1706                         i_size, 64 * 1024 * sizeof(ntfschar));
1707         iput(ino);
1708         mutex_lock(&ntfs_lock);
1709         if (!default_upcase) {
1710                 ntfs_debug("Using volume specified $UpCase since default is "
1711                                 "not present.");
1712                 mutex_unlock(&ntfs_lock);
1713                 return true;
1714         }
1715         max = default_upcase_len;
1716         if (max > vol->upcase_len)
1717                 max = vol->upcase_len;
1718         for (i = 0; i < max; i++)
1719                 if (vol->upcase[i] != default_upcase[i])
1720                         break;
1721         if (i == max) {
1722                 ntfs_free(vol->upcase);
1723                 vol->upcase = default_upcase;
1724                 vol->upcase_len = max;
1725                 ntfs_nr_upcase_users++;
1726                 mutex_unlock(&ntfs_lock);
1727                 ntfs_debug("Volume specified $UpCase matches default. Using "
1728                                 "default.");
1729                 return true;
1730         }
1731         mutex_unlock(&ntfs_lock);
1732         ntfs_debug("Using volume specified $UpCase since it does not match "
1733                         "the default.");
1734         return true;
1735 iput_upcase_failed:
1736         iput(ino);
1737         ntfs_free(vol->upcase);
1738         vol->upcase = NULL;
1739 upcase_failed:
1740         mutex_lock(&ntfs_lock);
1741         if (default_upcase) {
1742                 vol->upcase = default_upcase;
1743                 vol->upcase_len = default_upcase_len;
1744                 ntfs_nr_upcase_users++;
1745                 mutex_unlock(&ntfs_lock);
1746                 ntfs_error(sb, "Failed to load $UpCase from the volume. Using "
1747                                 "default.");
1748                 return true;
1749         }
1750         mutex_unlock(&ntfs_lock);
1751         ntfs_error(sb, "Failed to initialize upcase table.");
1752         return false;
1753 }
1754 
1755 /*
1756  * The lcn and mft bitmap inodes are NTFS-internal inodes with
1757  * their own special locking rules:
1758  */
1759 static struct lock_class_key
1760         lcnbmp_runlist_lock_key, lcnbmp_mrec_lock_key,
1761         mftbmp_runlist_lock_key, mftbmp_mrec_lock_key;
1762 
1763 /**
1764  * load_system_files - open the system files using normal functions
1765  * @vol:        ntfs super block describing device whose system files to load
1766  *
1767  * Open the system files with normal access functions and complete setting up
1768  * the ntfs super block @vol.
1769  *
1770  * Return 'true' on success or 'false' on error.
1771  */
1772 static bool load_system_files(ntfs_volume *vol)
1773 {
1774         struct super_block *sb = vol->sb;
1775         MFT_RECORD *m;
1776         VOLUME_INFORMATION *vi;
1777         ntfs_attr_search_ctx *ctx;
1778 #ifdef NTFS_RW
1779         RESTART_PAGE_HEADER *rp;
1780         int err;
1781 #endif /* NTFS_RW */
1782 
1783         ntfs_debug("Entering.");
1784 #ifdef NTFS_RW
1785         /* Get mft mirror inode compare the contents of $MFT and $MFTMirr. */
1786         if (!load_and_init_mft_mirror(vol) || !check_mft_mirror(vol)) {
1787                 static const char *es1 = "Failed to load $MFTMirr";
1788                 static const char *es2 = "$MFTMirr does not match $MFT";
1789                 static const char *es3 = ".  Run ntfsfix and/or chkdsk.";
1790 
1791                 /* If a read-write mount, convert it to a read-only mount. */
1792                 if (!(sb->s_flags & MS_RDONLY)) {
1793                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
1794                                         ON_ERRORS_CONTINUE))) {
1795                                 ntfs_error(sb, "%s and neither on_errors="
1796                                                 "continue nor on_errors="
1797                                                 "remount-ro was specified%s",
1798                                                 !vol->mftmirr_ino ? es1 : es2,
1799                                                 es3);
1800                                 goto iput_mirr_err_out;
1801                         }
1802                         sb->s_flags |= MS_RDONLY;
1803                         ntfs_error(sb, "%s.  Mounting read-only%s",
1804                                         !vol->mftmirr_ino ? es1 : es2, es3);
1805                 } else
1806                         ntfs_warning(sb, "%s.  Will not be able to remount "
1807                                         "read-write%s",
1808                                         !vol->mftmirr_ino ? es1 : es2, es3);
1809                 /* This will prevent a read-write remount. */
1810                 NVolSetErrors(vol);
1811         }
1812 #endif /* NTFS_RW */
1813         /* Get mft bitmap attribute inode. */
1814         vol->mftbmp_ino = ntfs_attr_iget(vol->mft_ino, AT_BITMAP, NULL, 0);
1815         if (IS_ERR(vol->mftbmp_ino)) {
1816                 ntfs_error(sb, "Failed to load $MFT/$BITMAP attribute.");
1817                 goto iput_mirr_err_out;
1818         }
1819         lockdep_set_class(&NTFS_I(vol->mftbmp_ino)->runlist.lock,
1820                            &mftbmp_runlist_lock_key);
1821         lockdep_set_class(&NTFS_I(vol->mftbmp_ino)->mrec_lock,
1822                            &mftbmp_mrec_lock_key);
1823         /* Read upcase table and setup @vol->upcase and @vol->upcase_len. */
1824         if (!load_and_init_upcase(vol))
1825                 goto iput_mftbmp_err_out;
1826 #ifdef NTFS_RW
1827         /*
1828          * Read attribute definitions table and setup @vol->attrdef and
1829          * @vol->attrdef_size.
1830          */
1831         if (!load_and_init_attrdef(vol))
1832                 goto iput_upcase_err_out;
1833 #endif /* NTFS_RW */
1834         /*
1835          * Get the cluster allocation bitmap inode and verify the size, no
1836          * need for any locking at this stage as we are already running
1837          * exclusively as we are mount in progress task.
1838          */
1839         vol->lcnbmp_ino = ntfs_iget(sb, FILE_Bitmap);
1840         if (IS_ERR(vol->lcnbmp_ino) || is_bad_inode(vol->lcnbmp_ino)) {
1841                 if (!IS_ERR(vol->lcnbmp_ino))
1842                         iput(vol->lcnbmp_ino);
1843                 goto bitmap_failed;
1844         }
1845         lockdep_set_class(&NTFS_I(vol->lcnbmp_ino)->runlist.lock,
1846                            &lcnbmp_runlist_lock_key);
1847         lockdep_set_class(&NTFS_I(vol->lcnbmp_ino)->mrec_lock,
1848                            &lcnbmp_mrec_lock_key);
1849 
1850         NInoSetSparseDisabled(NTFS_I(vol->lcnbmp_ino));
1851         if ((vol->nr_clusters + 7) >> 3 > i_size_read(vol->lcnbmp_ino)) {
1852                 iput(vol->lcnbmp_ino);
1853 bitmap_failed:
1854                 ntfs_error(sb, "Failed to load $Bitmap.");
1855                 goto iput_attrdef_err_out;
1856         }
1857         /*
1858          * Get the volume inode and setup our cache of the volume flags and
1859          * version.
1860          */
1861         vol->vol_ino = ntfs_iget(sb, FILE_Volume);
1862         if (IS_ERR(vol->vol_ino) || is_bad_inode(vol->vol_ino)) {
1863                 if (!IS_ERR(vol->vol_ino))
1864                         iput(vol->vol_ino);
1865 volume_failed:
1866                 ntfs_error(sb, "Failed to load $Volume.");
1867                 goto iput_lcnbmp_err_out;
1868         }
1869         m = map_mft_record(NTFS_I(vol->vol_ino));
1870         if (IS_ERR(m)) {
1871 iput_volume_failed:
1872                 iput(vol->vol_ino);
1873                 goto volume_failed;
1874         }
1875         if (!(ctx = ntfs_attr_get_search_ctx(NTFS_I(vol->vol_ino), m))) {
1876                 ntfs_error(sb, "Failed to get attribute search context.");
1877                 goto get_ctx_vol_failed;
1878         }
1879         if (ntfs_attr_lookup(AT_VOLUME_INFORMATION, NULL, 0, 0, 0, NULL, 0,
1880                         ctx) || ctx->attr->non_resident || ctx->attr->flags) {
1881 err_put_vol:
1882                 ntfs_attr_put_search_ctx(ctx);
1883 get_ctx_vol_failed:
1884                 unmap_mft_record(NTFS_I(vol->vol_ino));
1885                 goto iput_volume_failed;
1886         }
1887         vi = (VOLUME_INFORMATION*)((char*)ctx->attr +
1888                         le16_to_cpu(ctx->attr->data.resident.value_offset));
1889         /* Some bounds checks. */
1890         if ((u8*)vi < (u8*)ctx->attr || (u8*)vi +
1891                         le32_to_cpu(ctx->attr->data.resident.value_length) >
1892                         (u8*)ctx->attr + le32_to_cpu(ctx->attr->length))
1893                 goto err_put_vol;
1894         /* Copy the volume flags and version to the ntfs_volume structure. */
1895         vol->vol_flags = vi->flags;
1896         vol->major_ver = vi->major_ver;
1897         vol->minor_ver = vi->minor_ver;
1898         ntfs_attr_put_search_ctx(ctx);
1899         unmap_mft_record(NTFS_I(vol->vol_ino));
1900         pr_info("volume version %i.%i.\n", vol->major_ver,
1901                         vol->minor_ver);
1902         if (vol->major_ver < 3 && NVolSparseEnabled(vol)) {
1903                 ntfs_warning(vol->sb, "Disabling sparse support due to NTFS "
1904                                 "volume version %i.%i (need at least version "
1905                                 "3.0).", vol->major_ver, vol->minor_ver);
1906                 NVolClearSparseEnabled(vol);
1907         }
1908 #ifdef NTFS_RW
1909         /* Make sure that no unsupported volume flags are set. */
1910         if (vol->vol_flags & VOLUME_MUST_MOUNT_RO_MASK) {
1911                 static const char *es1a = "Volume is dirty";
1912                 static const char *es1b = "Volume has been modified by chkdsk";
1913                 static const char *es1c = "Volume has unsupported flags set";
1914                 static const char *es2a = ".  Run chkdsk and mount in Windows.";
1915                 static const char *es2b = ".  Mount in Windows.";
1916                 const char *es1, *es2;
1917 
1918                 es2 = es2a;
1919                 if (vol->vol_flags & VOLUME_IS_DIRTY)
1920                         es1 = es1a;
1921                 else if (vol->vol_flags & VOLUME_MODIFIED_BY_CHKDSK) {
1922                         es1 = es1b;
1923                         es2 = es2b;
1924                 } else {
1925                         es1 = es1c;
1926                         ntfs_warning(sb, "Unsupported volume flags 0x%x "
1927                                         "encountered.",
1928                                         (unsigned)le16_to_cpu(vol->vol_flags));
1929                 }
1930                 /* If a read-write mount, convert it to a read-only mount. */
1931                 if (!(sb->s_flags & MS_RDONLY)) {
1932                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
1933                                         ON_ERRORS_CONTINUE))) {
1934                                 ntfs_error(sb, "%s and neither on_errors="
1935                                                 "continue nor on_errors="
1936                                                 "remount-ro was specified%s",
1937                                                 es1, es2);
1938                                 goto iput_vol_err_out;
1939                         }
1940                         sb->s_flags |= MS_RDONLY;
1941                         ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
1942                 } else
1943                         ntfs_warning(sb, "%s.  Will not be able to remount "
1944                                         "read-write%s", es1, es2);
1945                 /*
1946                  * Do not set NVolErrors() because ntfs_remount() re-checks the
1947                  * flags which we need to do in case any flags have changed.
1948                  */
1949         }
1950         /*
1951          * Get the inode for the logfile, check it and determine if the volume
1952          * was shutdown cleanly.
1953          */
1954         rp = NULL;
1955         if (!load_and_check_logfile(vol, &rp) ||
1956                         !ntfs_is_logfile_clean(vol->logfile_ino, rp)) {
1957                 static const char *es1a = "Failed to load $LogFile";
1958                 static const char *es1b = "$LogFile is not clean";
1959                 static const char *es2 = ".  Mount in Windows.";
1960                 const char *es1;
1961 
1962                 es1 = !vol->logfile_ino ? es1a : es1b;
1963                 /* If a read-write mount, convert it to a read-only mount. */
1964                 if (!(sb->s_flags & MS_RDONLY)) {
1965                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
1966                                         ON_ERRORS_CONTINUE))) {
1967                                 ntfs_error(sb, "%s and neither on_errors="
1968                                                 "continue nor on_errors="
1969                                                 "remount-ro was specified%s",
1970                                                 es1, es2);
1971                                 if (vol->logfile_ino) {
1972                                         BUG_ON(!rp);
1973                                         ntfs_free(rp);
1974                                 }
1975                                 goto iput_logfile_err_out;
1976                         }
1977                         sb->s_flags |= MS_RDONLY;
1978                         ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
1979                 } else
1980                         ntfs_warning(sb, "%s.  Will not be able to remount "
1981                                         "read-write%s", es1, es2);
1982                 /* This will prevent a read-write remount. */
1983                 NVolSetErrors(vol);
1984         }
1985         ntfs_free(rp);
1986 #endif /* NTFS_RW */
1987         /* Get the root directory inode so we can do path lookups. */
1988         vol->root_ino = ntfs_iget(sb, FILE_root);
1989         if (IS_ERR(vol->root_ino) || is_bad_inode(vol->root_ino)) {
1990                 if (!IS_ERR(vol->root_ino))
1991                         iput(vol->root_ino);
1992                 ntfs_error(sb, "Failed to load root directory.");
1993                 goto iput_logfile_err_out;
1994         }
1995 #ifdef NTFS_RW
1996         /*
1997          * Check if Windows is suspended to disk on the target volume.  If it
1998          * is hibernated, we must not write *anything* to the disk so set
1999          * NVolErrors() without setting the dirty volume flag and mount
2000          * read-only.  This will prevent read-write remounting and it will also
2001          * prevent all writes.
2002          */
2003         err = check_windows_hibernation_status(vol);
2004         if (unlikely(err)) {
2005                 static const char *es1a = "Failed to determine if Windows is "
2006                                 "hibernated";
2007                 static const char *es1b = "Windows is hibernated";
2008                 static const char *es2 = ".  Run chkdsk.";
2009                 const char *es1;
2010 
2011                 es1 = err < 0 ? es1a : es1b;
2012                 /* If a read-write mount, convert it to a read-only mount. */
2013                 if (!(sb->s_flags & MS_RDONLY)) {
2014                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2015                                         ON_ERRORS_CONTINUE))) {
2016                                 ntfs_error(sb, "%s and neither on_errors="
2017                                                 "continue nor on_errors="
2018                                                 "remount-ro was specified%s",
2019                                                 es1, es2);
2020                                 goto iput_root_err_out;
2021                         }
2022                         sb->s_flags |= MS_RDONLY;
2023                         ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2024                 } else
2025                         ntfs_warning(sb, "%s.  Will not be able to remount "
2026                                         "read-write%s", es1, es2);
2027                 /* This will prevent a read-write remount. */
2028                 NVolSetErrors(vol);
2029         }
2030         /* If (still) a read-write mount, mark the volume dirty. */
2031         if (!(sb->s_flags & MS_RDONLY) &&
2032                         ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY)) {
2033                 static const char *es1 = "Failed to set dirty bit in volume "
2034                                 "information flags";
2035                 static const char *es2 = ".  Run chkdsk.";
2036 
2037                 /* Convert to a read-only mount. */
2038                 if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2039                                 ON_ERRORS_CONTINUE))) {
2040                         ntfs_error(sb, "%s and neither on_errors=continue nor "
2041                                         "on_errors=remount-ro was specified%s",
2042                                         es1, es2);
2043                         goto iput_root_err_out;
2044                 }
2045                 ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2046                 sb->s_flags |= MS_RDONLY;
2047                 /*
2048                  * Do not set NVolErrors() because ntfs_remount() might manage
2049                  * to set the dirty flag in which case all would be well.
2050                  */
2051         }
2052 #if 0
2053         // TODO: Enable this code once we start modifying anything that is
2054         //       different between NTFS 1.2 and 3.x...
2055         /*
2056          * If (still) a read-write mount, set the NT4 compatibility flag on
2057          * newer NTFS version volumes.
2058          */
2059         if (!(sb->s_flags & MS_RDONLY) && (vol->major_ver > 1) &&
2060                         ntfs_set_volume_flags(vol, VOLUME_MOUNTED_ON_NT4)) {
2061                 static const char *es1 = "Failed to set NT4 compatibility flag";
2062                 static const char *es2 = ".  Run chkdsk.";
2063 
2064                 /* Convert to a read-only mount. */
2065                 if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2066                                 ON_ERRORS_CONTINUE))) {
2067                         ntfs_error(sb, "%s and neither on_errors=continue nor "
2068                                         "on_errors=remount-ro was specified%s",
2069                                         es1, es2);
2070                         goto iput_root_err_out;
2071                 }
2072                 ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2073                 sb->s_flags |= MS_RDONLY;
2074                 NVolSetErrors(vol);
2075         }
2076 #endif
2077         /* If (still) a read-write mount, empty the logfile. */
2078         if (!(sb->s_flags & MS_RDONLY) &&
2079                         !ntfs_empty_logfile(vol->logfile_ino)) {
2080                 static const char *es1 = "Failed to empty $LogFile";
2081                 static const char *es2 = ".  Mount in Windows.";
2082 
2083                 /* Convert to a read-only mount. */
2084                 if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2085                                 ON_ERRORS_CONTINUE))) {
2086                         ntfs_error(sb, "%s and neither on_errors=continue nor "
2087                                         "on_errors=remount-ro was specified%s",
2088                                         es1, es2);
2089                         goto iput_root_err_out;
2090                 }
2091                 ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2092                 sb->s_flags |= MS_RDONLY;
2093                 NVolSetErrors(vol);
2094         }
2095 #endif /* NTFS_RW */
2096         /* If on NTFS versions before 3.0, we are done. */
2097         if (unlikely(vol->major_ver < 3))
2098                 return true;
2099         /* NTFS 3.0+ specific initialization. */
2100         /* Get the security descriptors inode. */
2101         vol->secure_ino = ntfs_iget(sb, FILE_Secure);
2102         if (IS_ERR(vol->secure_ino) || is_bad_inode(vol->secure_ino)) {
2103                 if (!IS_ERR(vol->secure_ino))
2104                         iput(vol->secure_ino);
2105                 ntfs_error(sb, "Failed to load $Secure.");
2106                 goto iput_root_err_out;
2107         }
2108         // TODO: Initialize security.
2109         /* Get the extended system files' directory inode. */
2110         vol->extend_ino = ntfs_iget(sb, FILE_Extend);
2111         if (IS_ERR(vol->extend_ino) || is_bad_inode(vol->extend_ino)) {
2112                 if (!IS_ERR(vol->extend_ino))
2113                         iput(vol->extend_ino);
2114                 ntfs_error(sb, "Failed to load $Extend.");
2115                 goto iput_sec_err_out;
2116         }
2117 #ifdef NTFS_RW
2118         /* Find the quota file, load it if present, and set it up. */
2119         if (!load_and_init_quota(vol)) {
2120                 static const char *es1 = "Failed to load $Quota";
2121                 static const char *es2 = ".  Run chkdsk.";
2122 
2123                 /* If a read-write mount, convert it to a read-only mount. */
2124                 if (!(sb->s_flags & MS_RDONLY)) {
2125                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2126                                         ON_ERRORS_CONTINUE))) {
2127                                 ntfs_error(sb, "%s and neither on_errors="
2128                                                 "continue nor on_errors="
2129                                                 "remount-ro was specified%s",
2130                                                 es1, es2);
2131                                 goto iput_quota_err_out;
2132                         }
2133                         sb->s_flags |= MS_RDONLY;
2134                         ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2135                 } else
2136                         ntfs_warning(sb, "%s.  Will not be able to remount "
2137                                         "read-write%s", es1, es2);
2138                 /* This will prevent a read-write remount. */
2139                 NVolSetErrors(vol);
2140         }
2141         /* If (still) a read-write mount, mark the quotas out of date. */
2142         if (!(sb->s_flags & MS_RDONLY) &&
2143                         !ntfs_mark_quotas_out_of_date(vol)) {
2144                 static const char *es1 = "Failed to mark quotas out of date";
2145                 static const char *es2 = ".  Run chkdsk.";
2146 
2147                 /* Convert to a read-only mount. */
2148                 if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2149                                 ON_ERRORS_CONTINUE))) {
2150                         ntfs_error(sb, "%s and neither on_errors=continue nor "
2151                                         "on_errors=remount-ro was specified%s",
2152                                         es1, es2);
2153                         goto iput_quota_err_out;
2154                 }
2155                 ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2156                 sb->s_flags |= MS_RDONLY;
2157                 NVolSetErrors(vol);
2158         }
2159         /*
2160          * Find the transaction log file ($UsnJrnl), load it if present, check
2161          * it, and set it up.
2162          */
2163         if (!load_and_init_usnjrnl(vol)) {
2164                 static const char *es1 = "Failed to load $UsnJrnl";
2165                 static const char *es2 = ".  Run chkdsk.";
2166 
2167                 /* If a read-write mount, convert it to a read-only mount. */
2168                 if (!(sb->s_flags & MS_RDONLY)) {
2169                         if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2170                                         ON_ERRORS_CONTINUE))) {
2171                                 ntfs_error(sb, "%s and neither on_errors="
2172                                                 "continue nor on_errors="
2173                                                 "remount-ro was specified%s",
2174                                                 es1, es2);
2175                                 goto iput_usnjrnl_err_out;
2176                         }
2177                         sb->s_flags |= MS_RDONLY;
2178                         ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2179                 } else
2180                         ntfs_warning(sb, "%s.  Will not be able to remount "
2181                                         "read-write%s", es1, es2);
2182                 /* This will prevent a read-write remount. */
2183                 NVolSetErrors(vol);
2184         }
2185         /* If (still) a read-write mount, stamp the transaction log. */
2186         if (!(sb->s_flags & MS_RDONLY) && !ntfs_stamp_usnjrnl(vol)) {
2187                 static const char *es1 = "Failed to stamp transaction log "
2188                                 "($UsnJrnl)";
2189                 static const char *es2 = ".  Run chkdsk.";
2190 
2191                 /* Convert to a read-only mount. */
2192                 if (!(vol->on_errors & (ON_ERRORS_REMOUNT_RO |
2193                                 ON_ERRORS_CONTINUE))) {
2194                         ntfs_error(sb, "%s and neither on_errors=continue nor "
2195                                         "on_errors=remount-ro was specified%s",
2196                                         es1, es2);
2197                         goto iput_usnjrnl_err_out;
2198                 }
2199                 ntfs_error(sb, "%s.  Mounting read-only%s", es1, es2);
2200                 sb->s_flags |= MS_RDONLY;
2201                 NVolSetErrors(vol);
2202         }
2203 #endif /* NTFS_RW */
2204         return true;
2205 #ifdef NTFS_RW
2206 iput_usnjrnl_err_out:
2207         if (vol->usnjrnl_j_ino)
2208                 iput(vol->usnjrnl_j_ino);
2209         if (vol->usnjrnl_max_ino)
2210                 iput(vol->usnjrnl_max_ino);
2211         if (vol->usnjrnl_ino)
2212                 iput(vol->usnjrnl_ino);
2213 iput_quota_err_out:
2214         if (vol->quota_q_ino)
2215                 iput(vol->quota_q_ino);
2216         if (vol->quota_ino)
2217                 iput(vol->quota_ino);
2218         iput(vol->extend_ino);
2219 #endif /* NTFS_RW */
2220 iput_sec_err_out:
2221         iput(vol->secure_ino);
2222 iput_root_err_out:
2223         iput(vol->root_ino);
2224 iput_logfile_err_out:
2225 #ifdef NTFS_RW
2226         if (vol->logfile_ino)
2227                 iput(vol->logfile_ino);
2228 iput_vol_err_out:
2229 #endif /* NTFS_RW */
2230         iput(vol->vol_ino);
2231 iput_lcnbmp_err_out:
2232         iput(vol->lcnbmp_ino);
2233 iput_attrdef_err_out:
2234         vol->attrdef_size = 0;
2235         if (vol->attrdef) {
2236                 ntfs_free(vol->attrdef);
2237                 vol->attrdef = NULL;
2238         }
2239 #ifdef NTFS_RW
2240 iput_upcase_err_out:
2241 #endif /* NTFS_RW */
2242         vol->upcase_len = 0;
2243         mutex_lock(&ntfs_lock);
2244         if (vol->upcase == default_upcase) {
2245                 ntfs_nr_upcase_users--;
2246                 vol->upcase = NULL;
2247         }
2248         mutex_unlock(&ntfs_lock);
2249         if (vol->upcase) {
2250                 ntfs_free(vol->upcase);
2251                 vol->upcase = NULL;
2252         }
2253 iput_mftbmp_err_out:
2254         iput(vol->mftbmp_ino);
2255 iput_mirr_err_out:
2256 #ifdef NTFS_RW
2257         if (vol->mftmirr_ino)
2258                 iput(vol->mftmirr_ino);
2259 #endif /* NTFS_RW */
2260         return false;
2261 }
2262 
2263 /**
2264  * ntfs_put_super - called by the vfs to unmount a volume
2265  * @sb:         vfs superblock of volume to unmount
2266  *
2267  * ntfs_put_super() is called by the VFS (from fs/super.c::do_umount()) when
2268  * the volume is being unmounted (umount system call has been invoked) and it
2269  * releases all inodes and memory belonging to the NTFS specific part of the
2270  * super block.
2271  */
2272 static void ntfs_put_super(struct super_block *sb)
2273 {
2274         ntfs_volume *vol = NTFS_SB(sb);
2275 
2276         ntfs_debug("Entering.");
2277 
2278 #ifdef NTFS_RW
2279         /*
2280          * Commit all inodes while they are still open in case some of them
2281          * cause others to be dirtied.
2282          */
2283         ntfs_commit_inode(vol->vol_ino);
2284 
2285         /* NTFS 3.0+ specific. */
2286         if (vol->major_ver >= 3) {
2287                 if (vol->usnjrnl_j_ino)
2288                         ntfs_commit_inode(vol->usnjrnl_j_ino);
2289                 if (vol->usnjrnl_max_ino)
2290                         ntfs_commit_inode(vol->usnjrnl_max_ino);
2291                 if (vol->usnjrnl_ino)
2292                         ntfs_commit_inode(vol->usnjrnl_ino);
2293                 if (vol->quota_q_ino)
2294                         ntfs_commit_inode(vol->quota_q_ino);
2295                 if (vol->quota_ino)
2296                         ntfs_commit_inode(vol->quota_ino);
2297                 if (vol->extend_ino)
2298                         ntfs_commit_inode(vol->extend_ino);
2299                 if (vol->secure_ino)
2300                         ntfs_commit_inode(vol->secure_ino);
2301         }
2302 
2303         ntfs_commit_inode(vol->root_ino);
2304 
2305         down_write(&vol->lcnbmp_lock);
2306         ntfs_commit_inode(vol->lcnbmp_ino);
2307         up_write(&vol->lcnbmp_lock);
2308 
2309         down_write(&vol->mftbmp_lock);
2310         ntfs_commit_inode(vol->mftbmp_ino);
2311         up_write(&vol->mftbmp_lock);
2312 
2313         if (vol->logfile_ino)
2314                 ntfs_commit_inode(vol->logfile_ino);
2315 
2316         if (vol->mftmirr_ino)
2317                 ntfs_commit_inode(vol->mftmirr_ino);
2318         ntfs_commit_inode(vol->mft_ino);
2319 
2320         /*
2321          * If a read-write mount and no volume errors have occurred, mark the
2322          * volume clean.  Also, re-commit all affected inodes.
2323          */
2324         if (!(sb->s_flags & MS_RDONLY)) {
2325                 if (!NVolErrors(vol)) {
2326                         if (ntfs_clear_volume_flags(vol, VOLUME_IS_DIRTY))
2327                                 ntfs_warning(sb, "Failed to clear dirty bit "
2328                                                 "in volume information "
2329                                                 "flags.  Run chkdsk.");
2330                         ntfs_commit_inode(vol->vol_ino);
2331                         ntfs_commit_inode(vol->root_ino);
2332                         if (vol->mftmirr_ino)
2333                                 ntfs_commit_inode(vol->mftmirr_ino);
2334                         ntfs_commit_inode(vol->mft_ino);
2335                 } else {
2336                         ntfs_warning(sb, "Volume has errors.  Leaving volume "
2337                                         "marked dirty.  Run chkdsk.");
2338                 }
2339         }
2340 #endif /* NTFS_RW */
2341 
2342         iput(vol->vol_ino);
2343         vol->vol_ino = NULL;
2344 
2345         /* NTFS 3.0+ specific clean up. */
2346         if (vol->major_ver >= 3) {
2347 #ifdef NTFS_RW
2348                 if (vol->usnjrnl_j_ino) {
2349                         iput(vol->usnjrnl_j_ino);
2350                         vol->usnjrnl_j_ino = NULL;
2351                 }
2352                 if (vol->usnjrnl_max_ino) {
2353                         iput(vol->usnjrnl_max_ino);
2354                         vol->usnjrnl_max_ino = NULL;
2355                 }
2356                 if (vol->usnjrnl_ino) {
2357                         iput(vol->usnjrnl_ino);
2358                         vol->usnjrnl_ino = NULL;
2359                 }
2360                 if (vol->quota_q_ino) {
2361                         iput(vol->quota_q_ino);
2362                         vol->quota_q_ino = NULL;
2363                 }
2364                 if (vol->quota_ino) {
2365                         iput(vol->quota_ino);
2366                         vol->quota_ino = NULL;
2367                 }
2368 #endif /* NTFS_RW */
2369                 if (vol->extend_ino) {
2370                         iput(vol->extend_ino);
2371                         vol->extend_ino = NULL;
2372                 }
2373                 if (vol->secure_ino) {
2374                         iput(vol->secure_ino);
2375                         vol->secure_ino = NULL;
2376                 }
2377         }
2378 
2379         iput(vol->root_ino);
2380         vol->root_ino = NULL;
2381 
2382         down_write(&vol->lcnbmp_lock);
2383         iput(vol->lcnbmp_ino);
2384         vol->lcnbmp_ino = NULL;
2385         up_write(&vol->lcnbmp_lock);
2386 
2387         down_write(&vol->mftbmp_lock);
2388         iput(vol->mftbmp_ino);
2389         vol->mftbmp_ino = NULL;
2390         up_write(&vol->mftbmp_lock);
2391 
2392 #ifdef NTFS_RW
2393         if (vol->logfile_ino) {
2394                 iput(vol->logfile_ino);
2395                 vol->logfile_ino = NULL;
2396         }
2397         if (vol->mftmirr_ino) {
2398                 /* Re-commit the mft mirror and mft just in case. */
2399                 ntfs_commit_inode(vol->mftmirr_ino);
2400                 ntfs_commit_inode(vol->mft_ino);
2401                 iput(vol->mftmirr_ino);
2402                 vol->mftmirr_ino = NULL;
2403         }
2404         /*
2405          * We should have no dirty inodes left, due to
2406          * mft.c::ntfs_mft_writepage() cleaning all the dirty pages as
2407          * the underlying mft records are written out and cleaned.
2408          */
2409         ntfs_commit_inode(vol->mft_ino);
2410         write_inode_now(vol->mft_ino, 1);
2411 #endif /* NTFS_RW */
2412 
2413         iput(vol->mft_ino);
2414         vol->mft_ino = NULL;
2415 
2416         /* Throw away the table of attribute definitions. */
2417         vol->attrdef_size = 0;
2418         if (vol->attrdef) {
2419                 ntfs_free(vol->attrdef);
2420                 vol->attrdef = NULL;
2421         }
2422         vol->upcase_len = 0;
2423         /*
2424          * Destroy the global default upcase table if necessary.  Also decrease
2425          * the number of upcase users if we are a user.
2426          */
2427         mutex_lock(&ntfs_lock);
2428         if (vol->upcase == default_upcase) {
2429                 ntfs_nr_upcase_users--;
2430                 vol->upcase = NULL;
2431         }
2432         if (!ntfs_nr_upcase_users && default_upcase) {
2433                 ntfs_free(default_upcase);
2434                 default_upcase = NULL;
2435         }
2436         if (vol->cluster_size <= 4096 && !--ntfs_nr_compression_users)
2437                 free_compression_buffers();
2438         mutex_unlock(&ntfs_lock);
2439         if (vol->upcase) {
2440                 ntfs_free(vol->upcase);
2441                 vol->upcase = NULL;
2442         }
2443 
2444         unload_nls(vol->nls_map);
2445 
2446         sb->s_fs_info = NULL;
2447         kfree(vol);
2448 }
2449 
2450 /**
2451  * get_nr_free_clusters - return the number of free clusters on a volume
2452  * @vol:        ntfs volume for which to obtain free cluster count
2453  *
2454  * Calculate the number of free clusters on the mounted NTFS volume @vol. We
2455  * actually calculate the number of clusters in use instead because this
2456  * allows us to not care about partial pages as these will be just zero filled
2457  * and hence not be counted as allocated clusters.
2458  *
2459  * The only particularity is that clusters beyond the end of the logical ntfs
2460  * volume will be marked as allocated to prevent errors which means we have to
2461  * discount those at the end. This is important as the cluster bitmap always
2462  * has a size in multiples of 8 bytes, i.e. up to 63 clusters could be outside
2463  * the logical volume and marked in use when they are not as they do not exist.
2464  *
2465  * If any pages cannot be read we assume all clusters in the erroring pages are
2466  * in use. This means we return an underestimate on errors which is better than
2467  * an overestimate.
2468  */
2469 static s64 get_nr_free_clusters(ntfs_volume *vol)
2470 {
2471         s64 nr_free = vol->nr_clusters;
2472         struct address_space *mapping = vol->lcnbmp_ino->i_mapping;
2473         struct page *page;
2474         pgoff_t index, max_index;
2475 
2476         ntfs_debug("Entering.");
2477         /* Serialize accesses to the cluster bitmap. */
2478         down_read(&vol->lcnbmp_lock);
2479         /*
2480          * Convert the number of bits into bytes rounded up, then convert into
2481          * multiples of PAGE_CACHE_SIZE, rounding up so that if we have one
2482          * full and one partial page max_index = 2.
2483          */
2484         max_index = (((vol->nr_clusters + 7) >> 3) + PAGE_CACHE_SIZE - 1) >>
2485                         PAGE_CACHE_SHIFT;
2486         /* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */
2487         ntfs_debug("Reading $Bitmap, max_index = 0x%lx, max_size = 0x%lx.",
2488                         max_index, PAGE_CACHE_SIZE / 4);
2489         for (index = 0; index < max_index; index++) {
2490                 unsigned long *kaddr;
2491 
2492                 /*
2493                  * Read the page from page cache, getting it from backing store
2494                  * if necessary, and increment the use count.
2495                  */
2496                 page = read_mapping_page(mapping, index, NULL);
2497                 /* Ignore pages which errored synchronously. */
2498                 if (IS_ERR(page)) {
2499                         ntfs_debug("read_mapping_page() error. Skipping "
2500                                         "page (index 0x%lx).", index);
2501                         nr_free -= PAGE_CACHE_SIZE * 8;
2502                         continue;
2503                 }
2504                 kaddr = kmap_atomic(page);
2505                 /*
2506                  * Subtract the number of set bits. If this
2507                  * is the last page and it is partial we don't really care as
2508                  * it just means we do a little extra work but it won't affect
2509                  * the result as all out of range bytes are set to zero by
2510                  * ntfs_readpage().
2511                  */
2512                 nr_free -= bitmap_weight(kaddr,
2513                                         PAGE_CACHE_SIZE * BITS_PER_BYTE);
2514                 kunmap_atomic(kaddr);
2515                 page_cache_release(page);
2516         }
2517         ntfs_debug("Finished reading $Bitmap, last index = 0x%lx.", index - 1);
2518         /*
2519          * Fixup for eventual bits outside logical ntfs volume (see function
2520          * description above).
2521          */
2522         if (vol->nr_clusters & 63)
2523                 nr_free += 64 - (vol->nr_clusters & 63);
2524         up_read(&vol->lcnbmp_lock);
2525         /* If errors occurred we may well have gone below zero, fix this. */
2526         if (nr_free < 0)
2527                 nr_free = 0;
2528         ntfs_debug("Exiting.");
2529         return nr_free;
2530 }
2531 
2532 /**
2533  * __get_nr_free_mft_records - return the number of free inodes on a volume
2534  * @vol:        ntfs volume for which to obtain free inode count
2535  * @nr_free:    number of mft records in filesystem
2536  * @max_index:  maximum number of pages containing set bits
2537  *
2538  * Calculate the number of free mft records (inodes) on the mounted NTFS
2539  * volume @vol. We actually calculate the number of mft records in use instead
2540  * because this allows us to not care about partial pages as these will be just
2541  * zero filled and hence not be counted as allocated mft record.
2542  *
2543  * If any pages cannot be read we assume all mft records in the erroring pages
2544  * are in use. This means we return an underestimate on errors which is better
2545  * than an overestimate.
2546  *
2547  * NOTE: Caller must hold mftbmp_lock rw_semaphore for reading or writing.
2548  */
2549 static unsigned long __get_nr_free_mft_records(ntfs_volume *vol,
2550                 s64 nr_free, const pgoff_t max_index)
2551 {
2552         struct address_space *mapping = vol->mftbmp_ino->i_mapping;
2553         struct page *page;
2554         pgoff_t index;
2555 
2556         ntfs_debug("Entering.");
2557         /* Use multiples of 4 bytes, thus max_size is PAGE_CACHE_SIZE / 4. */
2558         ntfs_debug("Reading $MFT/$BITMAP, max_index = 0x%lx, max_size = "
2559                         "0x%lx.", max_index, PAGE_CACHE_SIZE / 4);
2560         for (index = 0; index < max_index; index++) {
2561                 unsigned long *kaddr;
2562 
2563                 /*
2564                  * Read the page from page cache, getting it from backing store
2565                  * if necessary, and increment the use count.
2566                  */
2567                 page = read_mapping_page(mapping, index, NULL);
2568                 /* Ignore pages which errored synchronously. */
2569                 if (IS_ERR(page)) {
2570                         ntfs_debug("read_mapping_page() error. Skipping "
2571                                         "page (index 0x%lx).", index);
2572                         nr_free -= PAGE_CACHE_SIZE * 8;
2573                         continue;
2574                 }
2575                 kaddr = kmap_atomic(page);
2576                 /*
2577                  * Subtract the number of set bits. If this
2578                  * is the last page and it is partial we don't really care as
2579                  * it just means we do a little extra work but it won't affect
2580                  * the result as all out of range bytes are set to zero by
2581                  * ntfs_readpage().
2582                  */
2583                 nr_free -= bitmap_weight(kaddr,
2584                                         PAGE_CACHE_SIZE * BITS_PER_BYTE);
2585                 kunmap_atomic(kaddr);
2586                 page_cache_release(page);
2587         }
2588         ntfs_debug("Finished reading $MFT/$BITMAP, last index = 0x%lx.",
2589                         index - 1);
2590         /* If errors occurred we may well have gone below zero, fix this. */
2591         if (nr_free < 0)
2592                 nr_free = 0;
2593         ntfs_debug("Exiting.");
2594         return nr_free;
2595 }
2596 
2597 /**
2598  * ntfs_statfs - return information about mounted NTFS volume
2599  * @dentry:     dentry from mounted volume
2600  * @sfs:        statfs structure in which to return the information
2601  *
2602  * Return information about the mounted NTFS volume @dentry in the statfs structure
2603  * pointed to by @sfs (this is initialized with zeros before ntfs_statfs is
2604  * called). We interpret the values to be correct of the moment in time at
2605  * which we are called. Most values are variable otherwise and this isn't just
2606  * the free values but the totals as well. For example we can increase the
2607  * total number of file nodes if we run out and we can keep doing this until
2608  * there is no more space on the volume left at all.
2609  *
2610  * Called from vfs_statfs which is used to handle the statfs, fstatfs, and
2611  * ustat system calls.
2612  *
2613  * Return 0 on success or -errno on error.
2614  */
2615 static int ntfs_statfs(struct dentry *dentry, struct kstatfs *sfs)
2616 {
2617         struct super_block *sb = dentry->d_sb;
2618         s64 size;
2619         ntfs_volume *vol = NTFS_SB(sb);
2620         ntfs_inode *mft_ni = NTFS_I(vol->mft_ino);
2621         pgoff_t max_index;
2622         unsigned long flags;
2623 
2624         ntfs_debug("Entering.");
2625         /* Type of filesystem. */
2626         sfs->f_type   = NTFS_SB_MAGIC;
2627         /* Optimal transfer block size. */
2628         sfs->f_bsize  = PAGE_CACHE_SIZE;
2629         /*
2630          * Total data blocks in filesystem in units of f_bsize and since
2631          * inodes are also stored in data blocs ($MFT is a file) this is just
2632          * the total clusters.
2633          */
2634         sfs->f_blocks = vol->nr_clusters << vol->cluster_size_bits >>
2635                                 PAGE_CACHE_SHIFT;
2636         /* Free data blocks in filesystem in units of f_bsize. */
2637         size          = get_nr_free_clusters(vol) << vol->cluster_size_bits >>
2638                                 PAGE_CACHE_SHIFT;
2639         if (size < 0LL)
2640                 size = 0LL;
2641         /* Free blocks avail to non-superuser, same as above on NTFS. */
2642         sfs->f_bavail = sfs->f_bfree = size;
2643         /* Serialize accesses to the inode bitmap. */
2644         down_read(&vol->mftbmp_lock);
2645         read_lock_irqsave(&mft_ni->size_lock, flags);
2646         size = i_size_read(vol->mft_ino) >> vol->mft_record_size_bits;
2647         /*
2648          * Convert the maximum number of set bits into bytes rounded up, then
2649          * convert into multiples of PAGE_CACHE_SIZE, rounding up so that if we
2650          * have one full and one partial page max_index = 2.
2651          */
2652         max_index = ((((mft_ni->initialized_size >> vol->mft_record_size_bits)
2653                         + 7) >> 3) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
2654         read_unlock_irqrestore(&mft_ni->size_lock, flags);
2655         /* Number of inodes in filesystem (at this point in time). */
2656         sfs->f_files = size;
2657         /* Free inodes in fs (based on current total count). */
2658         sfs->f_ffree = __get_nr_free_mft_records(vol, size, max_index);
2659         up_read(&vol->mftbmp_lock);
2660         /*
2661          * File system id. This is extremely *nix flavour dependent and even
2662          * within Linux itself all fs do their own thing. I interpret this to
2663          * mean a unique id associated with the mounted fs and not the id
2664          * associated with the filesystem driver, the latter is already given
2665          * by the filesystem type in sfs->f_type. Thus we use the 64-bit
2666          * volume serial number splitting it into two 32-bit parts. We enter
2667          * the least significant 32-bits in f_fsid[0] and the most significant
2668          * 32-bits in f_fsid[1].
2669          */
2670         sfs->f_fsid.val[0] = vol->serial_no & 0xffffffff;
2671         sfs->f_fsid.val[1] = (vol->serial_no >> 32) & 0xffffffff;
2672         /* Maximum length of filenames. */
2673         sfs->f_namelen     = NTFS_MAX_NAME_LEN;
2674         return 0;
2675 }
2676 
2677 #ifdef NTFS_RW
2678 static int ntfs_write_inode(struct inode *vi, struct writeback_control *wbc)
2679 {
2680         return __ntfs_write_inode(vi, wbc->sync_mode == WB_SYNC_ALL);
2681 }
2682 #endif
2683 
2684 /**
2685  * The complete super operations.
2686  */
2687 static const struct super_operations ntfs_sops = {
2688         .alloc_inode    = ntfs_alloc_big_inode,   /* VFS: Allocate new inode. */
2689         .destroy_inode  = ntfs_destroy_big_inode, /* VFS: Deallocate inode. */
2690 #ifdef NTFS_RW
2691         .write_inode    = ntfs_write_inode,     /* VFS: Write dirty inode to
2692                                                    disk. */
2693 #endif /* NTFS_RW */
2694         .put_super      = ntfs_put_super,       /* Syscall: umount. */
2695         .statfs         = ntfs_statfs,          /* Syscall: statfs */
2696         .remount_fs     = ntfs_remount,         /* Syscall: mount -o remount. */
2697         .evict_inode    = ntfs_evict_big_inode, /* VFS: Called when an inode is
2698                                                    removed from memory. */
2699         .show_options   = ntfs_show_options,    /* Show mount options in
2700                                                    proc. */
2701 };
2702 
2703 /**
2704  * ntfs_fill_super - mount an ntfs filesystem
2705  * @sb:         super block of ntfs filesystem to mount
2706  * @opt:        string containing the mount options
2707  * @silent:     silence error output
2708  *
2709  * ntfs_fill_super() is called by the VFS to mount the device described by @sb
2710  * with the mount otions in @data with the NTFS filesystem.
2711  *
2712  * If @silent is true, remain silent even if errors are detected. This is used
2713  * during bootup, when the kernel tries to mount the root filesystem with all
2714  * registered filesystems one after the other until one succeeds. This implies
2715  * that all filesystems except the correct one will quite correctly and
2716  * expectedly return an error, but nobody wants to see error messages when in
2717  * fact this is what is supposed to happen.
2718  *
2719  * NOTE: @sb->s_flags contains the mount options flags.
2720  */
2721 static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
2722 {
2723         ntfs_volume *vol;
2724         struct buffer_head *bh;
2725         struct inode *tmp_ino;
2726         int blocksize, result;
2727 
2728         /*
2729          * We do a pretty difficult piece of bootstrap by reading the
2730          * MFT (and other metadata) from disk into memory. We'll only
2731          * release this metadata during umount, so the locking patterns
2732          * observed during bootstrap do not count. So turn off the
2733          * observation of locking patterns (strictly for this context
2734          * only) while mounting NTFS. [The validator is still active
2735          * otherwise, even for this context: it will for example record
2736          * lock class registrations.]
2737          */
2738         lockdep_off();
2739         ntfs_debug("Entering.");
2740 #ifndef NTFS_RW
2741         sb->s_flags |= MS_RDONLY;
2742 #endif /* ! NTFS_RW */
2743         /* Allocate a new ntfs_volume and place it in sb->s_fs_info. */
2744         sb->s_fs_info = kmalloc(sizeof(ntfs_volume), GFP_NOFS);
2745         vol = NTFS_SB(sb);
2746         if (!vol) {
2747                 if (!silent)
2748                         ntfs_error(sb, "Allocation of NTFS volume structure "
2749                                         "failed. Aborting mount...");
2750                 lockdep_on();
2751                 return -ENOMEM;
2752         }
2753         /* Initialize ntfs_volume structure. */
2754         *vol = (ntfs_volume) {
2755                 .sb = sb,
2756                 /*
2757                  * Default is group and other don't have any access to files or
2758                  * directories while owner has full access. Further, files by
2759                  * default are not executable but directories are of course
2760                  * browseable.
2761                  */
2762                 .fmask = 0177,
2763                 .dmask = 0077,
2764         };
2765         init_rwsem(&vol->mftbmp_lock);
2766         init_rwsem(&vol->lcnbmp_lock);
2767 
2768         /* By default, enable sparse support. */
2769         NVolSetSparseEnabled(vol);
2770 
2771         /* Important to get the mount options dealt with now. */
2772         if (!parse_options(vol, (char*)opt))
2773                 goto err_out_now;
2774 
2775         /* We support sector sizes up to the PAGE_CACHE_SIZE. */
2776         if (bdev_logical_block_size(sb->s_bdev) > PAGE_CACHE_SIZE) {
2777                 if (!silent)
2778                         ntfs_error(sb, "Device has unsupported sector size "
2779                                         "(%i).  The maximum supported sector "
2780                                         "size on this architecture is %lu "
2781                                         "bytes.",
2782                                         bdev_logical_block_size(sb->s_bdev),
2783                                         PAGE_CACHE_SIZE);
2784                 goto err_out_now;
2785         }
2786         /*
2787          * Setup the device access block size to NTFS_BLOCK_SIZE or the hard
2788          * sector size, whichever is bigger.
2789          */
2790         blocksize = sb_min_blocksize(sb, NTFS_BLOCK_SIZE);
2791         if (blocksize < NTFS_BLOCK_SIZE) {
2792                 if (!silent)
2793                         ntfs_error(sb, "Unable to set device block size.");
2794                 goto err_out_now;
2795         }
2796         BUG_ON(blocksize != sb->s_blocksize);
2797         ntfs_debug("Set device block size to %i bytes (block size bits %i).",
2798                         blocksize, sb->s_blocksize_bits);
2799         /* Determine the size of the device in units of block_size bytes. */
2800         if (!i_size_read(sb->s_bdev->bd_inode)) {
2801                 if (!silent)
2802                         ntfs_error(sb, "Unable to determine device size.");
2803                 goto err_out_now;
2804         }
2805         vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
2806                         sb->s_blocksize_bits;
2807         /* Read the boot sector and return unlocked buffer head to it. */
2808         if (!(bh = read_ntfs_boot_sector(sb, silent))) {
2809                 if (!silent)
2810                         ntfs_error(sb, "Not an NTFS volume.");
2811                 goto err_out_now;
2812         }
2813         /*
2814          * Extract the data from the boot sector and setup the ntfs volume
2815          * using it.
2816          */
2817         result = parse_ntfs_boot_sector(vol, (NTFS_BOOT_SECTOR*)bh->b_data);
2818         brelse(bh);
2819         if (!result) {
2820                 if (!silent)
2821                         ntfs_error(sb, "Unsupported NTFS filesystem.");
2822                 goto err_out_now;
2823         }
2824         /*
2825          * If the boot sector indicates a sector size bigger than the current
2826          * device block size, switch the device block size to the sector size.
2827          * TODO: It may be possible to support this case even when the set
2828          * below fails, we would just be breaking up the i/o for each sector
2829          * into multiple blocks for i/o purposes but otherwise it should just
2830          * work.  However it is safer to leave disabled until someone hits this
2831          * error message and then we can get them to try it without the setting
2832          * so we know for sure that it works.
2833          */
2834         if (vol->sector_size > blocksize) {
2835                 blocksize = sb_set_blocksize(sb, vol->sector_size);
2836                 if (blocksize != vol->sector_size) {
2837                         if (!silent)
2838                                 ntfs_error(sb, "Unable to set device block "
2839                                                 "size to sector size (%i).",
2840                                                 vol->sector_size);
2841                         goto err_out_now;
2842                 }
2843                 BUG_ON(blocksize != sb->s_blocksize);
2844                 vol->nr_blocks = i_size_read(sb->s_bdev->bd_inode) >>
2845                                 sb->s_blocksize_bits;
2846                 ntfs_debug("Changed device block size to %i bytes (block size "
2847                                 "bits %i) to match volume sector size.",
2848                                 blocksize, sb->s_blocksize_bits);
2849         }
2850         /* Initialize the cluster and mft allocators. */
2851         ntfs_setup_allocators(vol);
2852         /* Setup remaining fields in the super block. */
2853         sb->s_magic = NTFS_SB_MAGIC;
2854         /*
2855          * Ntfs allows 63 bits for the file size, i.e. correct would be:
2856          *      sb->s_maxbytes = ~0ULL >> 1;
2857          * But the kernel uses a long as the page cache page index which on
2858          * 32-bit architectures is only 32-bits. MAX_LFS_FILESIZE is kernel
2859          * defined to the maximum the page cache page index can cope with
2860          * without overflowing the index or to 2^63 - 1, whichever is smaller.
2861          */
2862         sb->s_maxbytes = MAX_LFS_FILESIZE;
2863         /* Ntfs measures time in 100ns intervals. */
2864         sb->s_time_gran = 100;
2865         /*
2866          * Now load the metadata required for the page cache and our address
2867          * space operations to function. We do this by setting up a specialised
2868          * read_inode method and then just calling the normal iget() to obtain
2869          * the inode for $MFT which is sufficient to allow our normal inode
2870          * operations and associated address space operations to function.
2871          */
2872         sb->s_op = &ntfs_sops;
2873         tmp_ino = new_inode(sb);
2874         if (!tmp_ino) {
2875                 if (!silent)
2876                         ntfs_error(sb, "Failed to load essential metadata.");
2877                 goto err_out_now;
2878         }
2879         tmp_ino->i_ino = FILE_MFT;
2880         insert_inode_hash(tmp_ino);
2881         if (ntfs_read_inode_mount(tmp_ino) < 0) {
2882                 if (!silent)
2883                         ntfs_error(sb, "Failed to load essential metadata.");
2884                 goto iput_tmp_ino_err_out_now;
2885         }
2886         mutex_lock(&ntfs_lock);
2887         /*
2888          * The current mount is a compression user if the cluster size is
2889          * less than or equal 4kiB.
2890          */
2891         if (vol->cluster_size <= 4096 && !ntfs_nr_compression_users++) {
2892                 result = allocate_compression_buffers();
2893                 if (result) {
2894                         ntfs_error(NULL, "Failed to allocate buffers "
2895                                         "for compression engine.");
2896                         ntfs_nr_compression_users--;
2897                         mutex_unlock(&ntfs_lock);
2898                         goto iput_tmp_ino_err_out_now;
2899                 }
2900         }
2901         /*
2902          * Generate the global default upcase table if necessary.  Also
2903          * temporarily increment the number of upcase users to avoid race
2904          * conditions with concurrent (u)mounts.
2905          */
2906         if (!default_upcase)
2907                 default_upcase = generate_default_upcase();
2908         ntfs_nr_upcase_users++;
2909         mutex_unlock(&ntfs_lock);
2910         /*
2911          * From now on, ignore @silent parameter. If we fail below this line,
2912          * it will be due to a corrupt fs or a system error, so we report it.
2913          */
2914         /*
2915          * Open the system files with normal access functions and complete
2916          * setting up the ntfs super block.
2917          */
2918         if (!load_system_files(vol)) {
2919                 ntfs_error(sb, "Failed to load system files.");
2920                 goto unl_upcase_iput_tmp_ino_err_out_now;
2921         }
2922 
2923         /* We grab a reference, simulating an ntfs_iget(). */
2924         ihold(vol->root_ino);
2925         if ((sb->s_root = d_make_root(vol->root_ino))) {
2926                 ntfs_debug("Exiting, status successful.");
2927                 /* Release the default upcase if it has no users. */
2928                 mutex_lock(&ntfs_lock);
2929                 if (!--ntfs_nr_upcase_users && default_upcase) {
2930                         ntfs_free(default_upcase);
2931                         default_upcase = NULL;
2932                 }
2933                 mutex_unlock(&ntfs_lock);
2934                 sb->s_export_op = &ntfs_export_ops;
2935                 lockdep_on();
2936                 return 0;
2937         }
2938         ntfs_error(sb, "Failed to allocate root directory.");
2939         /* Clean up after the successful load_system_files() call from above. */
2940         // TODO: Use ntfs_put_super() instead of repeating all this code...
2941         // FIXME: Should mark the volume clean as the error is most likely
2942         //        -ENOMEM.
2943         iput(vol->vol_ino);
2944         vol->vol_ino = NULL;
2945         /* NTFS 3.0+ specific clean up. */
2946         if (vol->major_ver >= 3) {
2947 #ifdef NTFS_RW
2948                 if (vol->usnjrnl_j_ino) {
2949                         iput(vol->usnjrnl_j_ino);
2950                         vol->usnjrnl_j_ino = NULL;
2951                 }
2952                 if (vol->usnjrnl_max_ino) {
2953                         iput(vol->usnjrnl_max_ino);
2954                         vol->usnjrnl_max_ino = NULL;
2955                 }
2956                 if (vol->usnjrnl_ino) {
2957                         iput(vol->usnjrnl_ino);
2958                         vol->usnjrnl_ino = NULL;
2959                 }
2960                 if (vol->quota_q_ino) {
2961                         iput(vol->quota_q_ino);
2962                         vol->quota_q_ino = NULL;
2963                 }
2964                 if (vol->quota_ino) {
2965                         iput(vol->quota_ino);
2966                         vol->quota_ino = NULL;
2967                 }
2968 #endif /* NTFS_RW */
2969                 if (vol->extend_ino) {
2970                         iput(vol->extend_ino);
2971                         vol->extend_ino = NULL;
2972                 }
2973                 if (vol->secure_ino) {
2974                         iput(vol->secure_ino);
2975                         vol->secure_ino = NULL;
2976                 }
2977         }
2978         iput(vol->root_ino);
2979         vol->root_ino = NULL;
2980         iput(vol->lcnbmp_ino);
2981         vol->lcnbmp_ino = NULL;
2982         iput(vol->mftbmp_ino);
2983         vol->mftbmp_ino = NULL;
2984 #ifdef NTFS_RW
2985         if (vol->logfile_ino) {
2986                 iput(vol->logfile_ino);
2987                 vol->logfile_ino = NULL;
2988         }
2989         if (vol->mftmirr_ino) {
2990                 iput(vol->mftmirr_ino);
2991                 vol->mftmirr_ino = NULL;
2992         }
2993 #endif /* NTFS_RW */
2994         /* Throw away the table of attribute definitions. */
2995         vol->attrdef_size = 0;
2996         if (vol->attrdef) {
2997                 ntfs_free(vol->attrdef);
2998                 vol->attrdef = NULL;
2999         }
3000         vol->upcase_len = 0;
3001         mutex_lock(&ntfs_lock);
3002         if (vol->upcase == default_upcase) {
3003                 ntfs_nr_upcase_users--;
3004                 vol->upcase = NULL;
3005         }
3006         mutex_unlock(&ntfs_lock);
3007         if (vol->upcase) {
3008                 ntfs_free(vol->upcase);
3009                 vol->upcase = NULL;
3010         }
3011         if (vol->nls_map) {
3012                 unload_nls(vol->nls_map);
3013                 vol->nls_map = NULL;
3014         }
3015         /* Error exit code path. */
3016 unl_upcase_iput_tmp_ino_err_out_now:
3017         /*
3018          * Decrease the number of upcase users and destroy the global default
3019          * upcase table if necessary.
3020          */
3021         mutex_lock(&ntfs_lock);
3022         if (!--ntfs_nr_upcase_users && default_upcase) {
3023                 ntfs_free(default_upcase);
3024                 default_upcase = NULL;
3025         }
3026         if (vol->cluster_size <= 4096 && !--ntfs_nr_compression_users)
3027                 free_compression_buffers();
3028         mutex_unlock(&ntfs_lock);
3029 iput_tmp_ino_err_out_now:
3030         iput(tmp_ino);
3031         if (vol->mft_ino && vol->mft_ino != tmp_ino)
3032                 iput(vol->mft_ino);
3033         vol->mft_ino = NULL;
3034         /* Errors at this stage are irrelevant. */
3035 err_out_now:
3036         sb->s_fs_info = NULL;
3037         kfree(vol);
3038         ntfs_debug("Failed, returning -EINVAL.");
3039         lockdep_on();
3040         return -EINVAL;
3041 }
3042 
3043 /*
3044  * This is a slab cache to optimize allocations and deallocations of Unicode
3045  * strings of the maximum length allowed by NTFS, which is NTFS_MAX_NAME_LEN
3046  * (255) Unicode characters + a terminating NULL Unicode character.
3047  */
3048 struct kmem_cache *ntfs_name_cache;
3049 
3050 /* Slab caches for efficient allocation/deallocation of inodes. */
3051 struct kmem_cache *ntfs_inode_cache;
3052 struct kmem_cache *ntfs_big_inode_cache;
3053 
3054 /* Init once constructor for the inode slab cache. */
3055 static void ntfs_big_inode_init_once(void *foo)
3056 {
3057         ntfs_inode *ni = (ntfs_inode *)foo;
3058 
3059         inode_init_once(VFS_I(ni));
3060 }
3061 
3062 /*
3063  * Slab caches to optimize allocations and deallocations of attribute search
3064  * contexts and index contexts, respectively.
3065  */
3066 struct kmem_cache *ntfs_attr_ctx_cache;
3067 struct kmem_cache *ntfs_index_ctx_cache;
3068 
3069 /* Driver wide mutex. */
3070 DEFINE_MUTEX(ntfs_lock);
3071 
3072 static struct dentry *ntfs_mount(struct file_system_type *fs_type,
3073         int flags, const char *dev_name, void *data)
3074 {
3075         return mount_bdev(fs_type, flags, dev_name, data, ntfs_fill_super);
3076 }
3077 
3078 static struct file_system_type ntfs_fs_type = {
3079         .owner          = THIS_MODULE,
3080         .name           = "ntfs",
3081         .mount          = ntfs_mount,
3082         .kill_sb        = kill_block_super,
3083         .fs_flags       = FS_REQUIRES_DEV,
3084 };
3085 MODULE_ALIAS_FS("ntfs");
3086 
3087 /* Stable names for the slab caches. */
3088 static const char ntfs_index_ctx_cache_name[] = "ntfs_index_ctx_cache";
3089 static const char ntfs_attr_ctx_cache_name[] = "ntfs_attr_ctx_cache";
3090 static const char ntfs_name_cache_name[] = "ntfs_name_cache";
3091 static const char ntfs_inode_cache_name[] = "ntfs_inode_cache";
3092 static const char ntfs_big_inode_cache_name[] = "ntfs_big_inode_cache";
3093 
3094 static int __init init_ntfs_fs(void)
3095 {
3096         int err = 0;
3097 
3098         /* This may be ugly but it results in pretty output so who cares. (-8 */
3099         pr_info("driver " NTFS_VERSION " [Flags: R/"
3100 #ifdef NTFS_RW
3101                         "W"
3102 #else
3103                         "O"
3104 #endif
3105 #ifdef DEBUG
3106                         " DEBUG"
3107 #endif
3108 #ifdef MODULE
3109                         " MODULE"
3110 #endif
3111                         "].\n");
3112 
3113         ntfs_debug("Debug messages are enabled.");
3114 
3115         ntfs_index_ctx_cache = kmem_cache_create(ntfs_index_ctx_cache_name,
3116                         sizeof(ntfs_index_context), 0 /* offset */,
3117                         SLAB_HWCACHE_ALIGN, NULL /* ctor */);
3118         if (!ntfs_index_ctx_cache) {
3119                 pr_crit("Failed to create %s!\n", ntfs_index_ctx_cache_name);
3120                 goto ictx_err_out;
3121         }
3122         ntfs_attr_ctx_cache = kmem_cache_create(ntfs_attr_ctx_cache_name,
3123                         sizeof(ntfs_attr_search_ctx), 0 /* offset */,
3124                         SLAB_HWCACHE_ALIGN, NULL /* ctor */);
3125         if (!ntfs_attr_ctx_cache) {
3126                 pr_crit("NTFS: Failed to create %s!\n",
3127                         ntfs_attr_ctx_cache_name);
3128                 goto actx_err_out;
3129         }
3130 
3131         ntfs_name_cache = kmem_cache_create(ntfs_name_cache_name,
3132                         (NTFS_MAX_NAME_LEN+1) * sizeof(ntfschar), 0,
3133                         SLAB_HWCACHE_ALIGN, NULL);
3134         if (!ntfs_name_cache) {
3135                 pr_crit("Failed to create %s!\n", ntfs_name_cache_name);
3136                 goto name_err_out;
3137         }
3138 
3139         ntfs_inode_cache = kmem_cache_create(ntfs_inode_cache_name,
3140                         sizeof(ntfs_inode), 0,
3141                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
3142         if (!ntfs_inode_cache) {
3143                 pr_crit("Failed to create %s!\n", ntfs_inode_cache_name);
3144                 goto inode_err_out;
3145         }
3146 
3147         ntfs_big_inode_cache = kmem_cache_create(ntfs_big_inode_cache_name,
3148                         sizeof(big_ntfs_inode), 0,
3149                         SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
3150                         ntfs_big_inode_init_once);
3151         if (!ntfs_big_inode_cache) {
3152                 pr_crit("Failed to create %s!\n", ntfs_big_inode_cache_name);
3153                 goto big_inode_err_out;
3154         }
3155 
3156         /* Register the ntfs sysctls. */
3157         err = ntfs_sysctl(1);
3158         if (err) {
3159                 pr_crit("Failed to register NTFS sysctls!\n");
3160                 goto sysctl_err_out;
3161         }
3162 
3163         err = register_filesystem(&ntfs_fs_type);
3164         if (!err) {
3165                 ntfs_debug("NTFS driver registered successfully.");
3166                 return 0; /* Success! */
3167         }
3168         pr_crit("Failed to register NTFS filesystem driver!\n");
3169 
3170         /* Unregister the ntfs sysctls. */
3171         ntfs_sysctl(0);
3172 sysctl_err_out:
3173         kmem_cache_destroy(ntfs_big_inode_cache);
3174 big_inode_err_out:
3175         kmem_cache_destroy(ntfs_inode_cache);
3176 inode_err_out:
3177         kmem_cache_destroy(ntfs_name_cache);
3178 name_err_out:
3179         kmem_cache_destroy(ntfs_attr_ctx_cache);
3180 actx_err_out:
3181         kmem_cache_destroy(ntfs_index_ctx_cache);
3182 ictx_err_out:
3183         if (!err) {
3184                 pr_crit("Aborting NTFS filesystem driver registration...\n");
3185                 err = -ENOMEM;
3186         }
3187         return err;
3188 }
3189 
3190 static void __exit exit_ntfs_fs(void)
3191 {
3192         ntfs_debug("Unregistering NTFS driver.");
3193 
3194         unregister_filesystem(&ntfs_fs_type);
3195 
3196         /*
3197          * Make sure all delayed rcu free inodes are flushed before we
3198          * destroy cache.
3199          */
3200         rcu_barrier();
3201         kmem_cache_destroy(ntfs_big_inode_cache);
3202         kmem_cache_destroy(ntfs_inode_cache);
3203         kmem_cache_destroy(ntfs_name_cache);
3204         kmem_cache_destroy(ntfs_attr_ctx_cache);
3205         kmem_cache_destroy(ntfs_index_ctx_cache);
3206         /* Unregister the ntfs sysctls. */
3207         ntfs_sysctl(0);
3208 }
3209 
3210 MODULE_AUTHOR("Anton Altaparmakov <anton@tuxera.com>");
3211 MODULE_DESCRIPTION("NTFS 1.2/3.x driver - Copyright (c) 2001-2011 Anton Altaparmakov and Tuxera Inc.");
3212 MODULE_VERSION(NTFS_VERSION);
3213 MODULE_LICENSE("GPL");
3214 #ifdef DEBUG
3215 module_param(debug_msgs, bint, 0);
3216 MODULE_PARM_DESC(debug_msgs, "Enable debug messages.");
3217 #endif
3218 
3219 module_init(init_ntfs_fs)
3220 module_exit(exit_ntfs_fs)
3221 

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