6a38dc33e8cabbfb7b0dce837052a18bc28650a9
[wimlib] / src / mount_image.c
1 /*
2  * mount_image.c
3  *
4  * This file implements mounting of WIM files using FUSE, which stands for
5  * Filesystem in Userspace.  FUSE allows a filesystem to be implemented in a
6  * userspace process by implementing the filesystem primitives--- read(),
7  * write(), readdir(), etc.
8  */
9
10 /*
11  * Copyright (C) 2012 Eric Biggers
12  *
13  * This file is part of wimlib, a library for working with WIM files.
14  *
15  * wimlib is free software; you can redistribute it and/or modify it under the
16  * terms of the GNU General Public License as published by the Free
17  * Software Foundation; either version 3 of the License, or (at your option)
18  * any later version.
19  *
20  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
21  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
22  * A PARTICULAR PURPOSE. See the GNU General Public License for more
23  * details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with wimlib; if not, see http://www.gnu.org/licenses/.
27  */
28
29 #include "wimlib_internal.h"
30
31 #ifdef WITH_FUSE
32
33 #include "sha1.h"
34 #include "lookup_table.h"
35 #include "xml.h"
36 #include "buffer_io.h"
37 #include "timestamp.h"
38 #include <limits.h>
39 #include <stdlib.h>
40 #include <unistd.h>
41 #include <sys/wait.h>
42 #define FUSE_USE_VERSION 26
43 #include <errno.h>
44 #include <string.h>
45 #include <sys/time.h>
46 #include <fuse.h>
47 #include <ftw.h>
48 #include <mqueue.h>
49 #include <utime.h>
50 #include <signal.h>
51
52 #ifdef ENABLE_XATTR
53 #include <attr/xattr.h>
54 #endif
55
56 #define MSG_VERSION_TOO_HIGH    -1
57 #define MSG_BREAK_LOOP          -2
58
59 /* File descriptor to a file open on the WIM filesystem. */
60 struct wimlib_fd {
61         struct inode *f_inode;
62         struct lookup_table_entry *f_lte;
63         int staging_fd;
64         u16 idx;
65         u32 stream_id;
66 };
67
68 struct wimfs_context {
69         /* The WIMStruct for the mounted WIM. */
70         WIMStruct *wim;
71
72         /* Name of the staging directory for a read-write mount.  Whenever a new file is
73          * created, it is done so in the staging directory.  Furthermore, whenever a
74          * file in the WIM is modified, it is extracted to the staging directory.  If
75          * changes are commited when the WIM is unmounted, the file resources are merged
76          * in from the staging directory when writing the new WIM. */
77         char *staging_dir_name;
78         size_t staging_dir_name_len;
79
80         /* Flags passed to wimlib_mount(). */
81         int mount_flags;
82
83         int default_lookup_flags;
84
85         /* Next inode number to be assigned. */
86         u64 next_ino;
87
88         /* List of lookup table entries in the staging directory */
89         struct list_head staging_list;
90
91         /* List of inodes in the mounted image */
92         struct hlist_head *image_inode_list;
93
94         /* Name and message queue descriptors for message queues between the filesystem
95          * daemon process and the unmount process.  These are used when the filesystem
96          * is unmounted and the process running wimlib_mount() (i.e. the `imagex
97          * unmount' command) needs to communicate with the filesystem daemon running
98          * fuse_main() (i.e. that spawned by the `imagex mount' or `imagex mountrw'
99          * commands */
100         char *unmount_to_daemon_mq_name;
101         char *daemon_to_unmount_mq_name;
102         mqd_t unmount_to_daemon_mq;
103         mqd_t daemon_to_unmount_mq;
104 };
105
106 static void init_wimfs_context(struct wimfs_context *ctx)
107 {
108         memset(ctx, 0, sizeof(*ctx));
109         ctx->unmount_to_daemon_mq = (mqd_t)-1;
110         ctx->daemon_to_unmount_mq = (mqd_t)-1;
111         INIT_LIST_HEAD(&ctx->staging_list);
112 }
113
114 static inline struct wimfs_context *wimfs_get_context()
115 {
116         return (struct wimfs_context*)fuse_get_context()->private_data;
117 }
118
119 static inline WIMStruct *wimfs_get_WIMStruct()
120 {
121         return wimfs_get_context()->wim;
122 }
123
124 static inline bool wimfs_ctx_readonly(const struct wimfs_context *ctx)
125 {
126         return (ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) == 0;
127 }
128
129 static inline int get_lookup_flags(const struct wimfs_context *ctx)
130 {
131         return ctx->default_lookup_flags;
132 }
133
134 /* Returns nonzero if write permission is requested on the file open flags */
135 static inline int flags_writable(int open_flags)
136 {
137         return open_flags & (O_RDWR | O_WRONLY);
138 }
139
140 /*
141  * Allocate a file descriptor for a stream.
142  *
143  * @inode:      inode containing the stream we're opening
144  * @stream_id:  ID of the stream we're opening
145  * @lte:        Lookup table entry for the stream (may be NULL)
146  * @fd_ret:     Return the allocated file descriptor if successful.
147  * @readonly:   True if this is a read-only mount.
148  *
149  * Return 0 iff successful or error code if unsuccessful.
150  */
151 static int alloc_wimlib_fd(struct inode *inode,
152                            u32 stream_id,
153                            struct lookup_table_entry *lte,
154                            struct wimlib_fd **fd_ret,
155                            bool readonly)
156 {
157         static const u16 fds_per_alloc = 8;
158         static const u16 max_fds = 0xffff;
159         int ret;
160
161         pthread_mutex_lock(&inode->i_mutex);
162
163         DEBUG("Allocating fd for stream ID %u from inode %lx (open = %u, allocated = %u)",
164               stream_id, inode->ino, inode->num_opened_fds,
165               inode->num_allocated_fds);
166
167         if (inode->num_opened_fds == inode->num_allocated_fds) {
168                 struct wimlib_fd **fds;
169                 u16 num_new_fds;
170
171                 if (inode->num_allocated_fds == max_fds) {
172                         ret = -EMFILE;
173                         goto out;
174                 }
175                 num_new_fds = min(fds_per_alloc,
176                                   max_fds - inode->num_allocated_fds);
177
178                 fds = REALLOC(inode->fds,
179                               (inode->num_allocated_fds + num_new_fds) *
180                                 sizeof(inode->fds[0]));
181                 if (!fds) {
182                         ret = -ENOMEM;
183                         goto out;
184                 }
185                 memset(&fds[inode->num_allocated_fds], 0,
186                        num_new_fds * sizeof(fds[0]));
187                 inode->fds = fds;
188                 inode->num_allocated_fds += num_new_fds;
189         }
190         for (u16 i = 0; ; i++) {
191                 if (!inode->fds[i]) {
192                         struct wimlib_fd *fd = CALLOC(1, sizeof(*fd));
193                         if (!fd) {
194                                 ret = -ENOMEM;
195                                 break;
196                         }
197                         fd->f_inode    = inode;
198                         fd->f_lte      = lte;
199                         fd->staging_fd = -1;
200                         fd->idx        = i;
201                         fd->stream_id  = stream_id;
202                         *fd_ret        = fd;
203                         inode->fds[i]  = fd;
204                         inode->num_opened_fds++;
205                         if (lte && !readonly)
206                                 lte->num_opened_fds++;
207                         DEBUG("Allocated fd (idx = %u)", fd->idx);
208                         ret = 0;
209                         break;
210                 }
211         }
212 out:
213         pthread_mutex_unlock(&inode->i_mutex);
214         return ret;
215 }
216
217 static void inode_put_fd(struct inode *inode, struct wimlib_fd *fd)
218 {
219         wimlib_assert(inode != NULL);
220
221         pthread_mutex_lock(&inode->i_mutex);
222
223         wimlib_assert(fd->f_inode == inode);
224         wimlib_assert(inode->num_opened_fds != 0);
225         wimlib_assert(fd->idx < inode->num_allocated_fds);
226         wimlib_assert(inode->fds[fd->idx] == fd);
227
228         inode->fds[fd->idx] = NULL;
229         FREE(fd);
230         if (--inode->num_opened_fds == 0 && inode->link_count == 0) {
231                 pthread_mutex_unlock(&inode->i_mutex);
232                 free_inode(inode);
233         } else {
234                 pthread_mutex_unlock(&inode->i_mutex);
235         }
236 }
237
238 static int lte_put_fd(struct lookup_table_entry *lte, struct wimlib_fd *fd)
239 {
240         wimlib_assert(fd->f_lte == lte);
241
242         if (!lte) /* Empty stream with no lookup table entry */
243                 return 0;
244
245         /* Close staging file descriptor if needed. */
246
247         if (lte->resource_location == RESOURCE_IN_STAGING_FILE
248              && fd->staging_fd != -1)
249         {
250                 if (close(fd->staging_fd) != 0) {
251                         ERROR_WITH_ERRNO("Failed to close staging file");
252                         return -errno;
253                 }
254         }
255         lte_decrement_num_opened_fds(lte);
256         return 0;
257 }
258
259 /* Close a file descriptor. */
260 static int close_wimlib_fd(struct wimlib_fd *fd)
261 {
262         int ret;
263         DEBUG("Closing fd (inode = %lu, opened = %u, allocated = %u)",
264               fd->f_inode->ino, fd->f_inode->num_opened_fds,
265               fd->f_inode->num_allocated_fds);
266         ret = lte_put_fd(fd->f_lte, fd);
267         if (ret != 0)
268                 return ret;
269
270         inode_put_fd(fd->f_inode, fd);
271         return 0;
272 }
273
274 static int create_dentry(struct wimfs_context *ctx, const char *path,
275                          struct dentry **dentry_ret)
276 {
277         struct dentry *parent;
278         struct dentry *new;
279         const char *basename;
280
281         parent = get_parent_dentry(ctx->wim, path);
282         if (!parent)
283                 return -ENOENT;
284
285         if (!dentry_is_directory(parent))
286                 return -ENOTDIR;
287
288         basename = path_basename(path);
289         if (get_dentry_child_with_name(parent, basename))
290                 return -EEXIST;
291
292         new = new_dentry_with_inode(basename);
293         if (!new)
294                 return -ENOMEM;
295
296         new->d_inode->resolved = 1;
297         new->d_inode->ino = ctx->next_ino++;
298         dentry_add_child(parent, new);
299         hlist_add_head(&new->d_inode->hlist, ctx->image_inode_list);
300         *dentry_ret = new;
301         return 0;
302 }
303
304 /* Remove a dentry; i.e. remove a reference to the corresponding inode.
305  *
306  * If there are no remaining references to the inode either through dentries or
307  * open file descriptors, the inode is freed.  Otherwise, the inode is not
308  * removed, but the dentry is unlinked and freed.
309  *
310  * Either way, all lookup table entries referenced by the inode have their
311  * reference count decremented.  If a lookup table entry has no open file
312  * descriptors and no references remaining, it is freed, and the staging file is
313  * unlinked.
314  */
315 static void remove_dentry(struct dentry *dentry,
316                           struct lookup_table *lookup_table)
317 {
318         struct inode *inode = dentry->d_inode;
319         struct lookup_table_entry *lte;
320         unsigned i;
321
322         for (i = 0; i <= inode->num_ads; i++) {
323                 lte = inode_stream_lte_resolved(inode, i);
324                 if (lte)
325                         lte_decrement_refcnt(lte, lookup_table);
326         }
327         unlink_dentry(dentry);
328         put_dentry(dentry);
329 }
330
331 /* Transfers file attributes from a struct inode to a `stat' buffer.
332  *
333  * The lookup table entry tells us which stream in the inode we are statting.
334  * For a named data stream, everything returned is the same as the unnamed data
335  * stream except possibly the size and block count. */
336 static int inode_to_stbuf(const struct inode *inode,
337                           struct lookup_table_entry *lte, struct stat *stbuf)
338 {
339         if (inode_is_symlink(inode))
340                 stbuf->st_mode = S_IFLNK | 0777;
341         else if (inode_is_directory(inode))
342                 stbuf->st_mode = S_IFDIR | 0755;
343         else
344                 stbuf->st_mode = S_IFREG | 0755;
345
346         stbuf->st_ino   = (ino_t)inode->ino;
347         stbuf->st_nlink = inode->link_count;
348         stbuf->st_uid   = getuid();
349         stbuf->st_gid   = getgid();
350
351         if (lte) {
352                 if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
353                         struct stat native_stat;
354                         if (stat(lte->staging_file_name, &native_stat) != 0) {
355                                 DEBUG("Failed to stat `%s': %m",
356                                       lte->staging_file_name);
357                                 return -errno;
358                         }
359                         stbuf->st_size = native_stat.st_size;
360                 } else {
361                         stbuf->st_size = wim_resource_size(lte);
362                 }
363         } else {
364                 stbuf->st_size = 0;
365         }
366
367         stbuf->st_atime   = wim_timestamp_to_unix(inode->last_access_time);
368         stbuf->st_mtime   = wim_timestamp_to_unix(inode->last_write_time);
369         stbuf->st_ctime   = wim_timestamp_to_unix(inode->creation_time);
370         stbuf->st_blocks  = (stbuf->st_size + 511) / 512;
371         return 0;
372 }
373
374 /* Creates a new staging file and returns its file descriptor opened for
375  * writing.
376  *
377  * @name_ret: A location into which the a pointer to the newly allocated name of
378  *                      the staging file is stored.
379  * @return:  The file descriptor for the new file.  Returns -1 and sets errno on
380  *              error, for any reason possible from the creat() function.
381  */
382 static int create_staging_file(char **name_ret, int open_flags,
383                                struct wimfs_context *ctx)
384 {
385         size_t name_len;
386         char *name;
387         struct stat stbuf;
388         int fd;
389         int errno_save;
390
391         name_len = ctx->staging_dir_name_len + 1 + SHA1_HASH_SIZE;
392         name = MALLOC(name_len + 1);
393         if (!name) {
394                 errno = ENOMEM;
395                 return -1;
396         }
397
398         do {
399
400                 memcpy(name, ctx->staging_dir_name, ctx->staging_dir_name_len);
401                 name[ctx->staging_dir_name_len] = '/';
402                 randomize_char_array_with_alnum(name + ctx->staging_dir_name_len + 1,
403                                                 SHA1_HASH_SIZE);
404                 name[name_len] = '\0';
405
406
407         /* Just in case, verify that the randomly generated name doesn't name an
408          * existing file, and try again if so  */
409         } while (stat(name, &stbuf) == 0);
410
411         if (errno != ENOENT)
412                 /* other error! */
413                 return -1;
414
415         /* doesn't exist--- ok */
416
417         DEBUG("Creating staging file `%s'", name);
418
419         fd = open(name, open_flags | O_CREAT | O_TRUNC, 0600);
420         if (fd == -1) {
421                 errno_save = errno;
422                 FREE(name);
423                 errno = errno_save;
424         } else {
425                 *name_ret = name;
426         }
427         return fd;
428 }
429
430 /*
431  * Extract a WIM resource to the staging directory.
432  *
433  * @inode:  Inode that contains the stream we are extracting
434  *
435  * @stream_id: Identifier for the stream (it stays constant even if the indices
436  * of the stream entries are changed)
437  *
438  * @lte: Pointer to pointer to the lookup table entry for the stream we need to
439  * extract, or NULL if there was no lookup table entry present for the stream
440  *
441  * @size:  Number of bytes of the stream we want to extract (this supports the
442  * wimfs_truncate() function).  It may be more than the actual stream length, in
443  * which case the extra space is filled with zeroes.
444  *
445  * @ctx:  Context for the WIM filesystem.
446  *
447  * Returns 0 on success or a negative error code on failure.
448  */
449 static int extract_resource_to_staging_dir(struct inode *inode,
450                                            u32 stream_id,
451                                            struct lookup_table_entry **lte,
452                                            off_t size,
453                                            struct wimfs_context *ctx)
454 {
455         char *staging_file_name;
456         int ret;
457         int fd;
458         struct lookup_table_entry *old_lte, *new_lte;
459         off_t extract_size;
460
461         DEBUG("Extracting resource to staging dir: inode %"PRIu64", "
462               "stream id %"PRIu32, inode->ino, stream_id);
463
464         old_lte = *lte;
465
466         wimlib_assert(old_lte == NULL ||
467                       old_lte->resource_location != RESOURCE_IN_STAGING_FILE);
468
469         /* Create the staging file */
470         fd = create_staging_file(&staging_file_name, O_WRONLY, ctx);
471         if (fd == -1)
472                 return -errno;
473
474         /* Extract the stream to the staging file (possibly truncated) */
475         if (old_lte) {
476                 extract_size = min(wim_resource_size(old_lte), size);
477                 ret = extract_wim_resource_to_fd(old_lte, fd, extract_size);
478         } else {
479                 ret = 0;
480                 extract_size = 0;
481         }
482
483         /* In the case of truncate() to more than the file length, extend the
484          * file with zeroes by calling ftruncate() on the underlying staging
485          * file */
486         if (ret == 0 && size > extract_size)
487                 ret = ftruncate(fd, size);
488
489         /* Close the staging file descriptor and check for errors.  If there's
490          * an error, unlink the staging file. */
491         if (ret != 0 || close(fd) != 0) {
492                 if (errno != 0)
493                         ret = -errno;
494                 else
495                         ret = -EIO;
496                 close(fd);
497                 goto out_delete_staging_file;
498         }
499
500         /* Now deal with the lookup table entries.  We may be able to re-use the
501          * existing entry, but we may have to create a new one instead. */
502
503         if (old_lte && inode->link_count == old_lte->refcnt) {
504                 /* The reference count of the existing lookup table entry is the
505                  * same as the link count of the inode that contains the stream
506                  * we're opening.  Therefore, ALL the references to the lookup
507                  * table entry correspond to the stream we're trying to extract,
508                  * so the lookup table entry can be re-used.  */
509                 DEBUG("Re-using lookup table entry");
510                 lookup_table_unlink(ctx->wim->lookup_table, old_lte);
511                 new_lte = old_lte;
512         } else {
513                 if (old_lte) {
514                         /* There's an existing lookup table entry, but its
515                          * reference count is greater than the link count for
516                          * the inode containing a stream we're opening.
517                          * Therefore, we need to split the lookup table entry.
518                          */
519                         wimlib_assert(old_lte->refcnt > inode->link_count);
520                         DEBUG("Splitting lookup table entry "
521                               "(inode->link_count = %u, old_lte->refcnt = %u)",
522                               inode->link_count, old_lte->refcnt);
523                 }
524
525                 new_lte = new_lookup_table_entry();
526                 if (!new_lte) {
527                         ret = -ENOMEM;
528                         goto out_delete_staging_file;
529                 }
530
531                 /* There may already be open file descriptors to this stream if
532                  * it's previously been opened read-only, but just now we're
533                  * opening it read-write.  Identify those file descriptors and
534                  * change their lookup table entry pointers to point to the new
535                  * lookup table entry, and open staging file descriptors for
536                  * them.
537                  *
538                  * At the same time, we need to count the number of these opened
539                  * file descriptors to the new lookup table entry.  If there's
540                  * an old lookup table entry, this number needs to be subtracted
541                  * from the fd's opened to the old entry. */
542                 for (u16 i = 0, j = 0; j < inode->num_opened_fds; i++) {
543                         struct wimlib_fd *fd = inode->fds[i];
544                         if (fd) {
545                                 if (fd->stream_id == stream_id) {
546                                         wimlib_assert(fd->f_lte == old_lte);
547                                         wimlib_assert(fd->staging_fd == -1);
548                                         fd->f_lte = new_lte;
549                                         new_lte->num_opened_fds++;
550                                         fd->staging_fd = open(staging_file_name, O_RDONLY);
551                                         if (fd->staging_fd == -1) {
552                                                 ret = -errno;
553                                                 goto out_revert_fd_changes;
554                                         }
555                                 }
556                                 j++;
557                         }
558                 }
559                 DEBUG("%hu fd's were already opened to the file we extracted",
560                       new_lte->num_opened_fds);
561                 if (old_lte) {
562                         old_lte->num_opened_fds -= new_lte->num_opened_fds;
563                         old_lte->refcnt -= inode->link_count;
564                 }
565         }
566
567         new_lte->refcnt                       = inode->link_count;
568         new_lte->resource_location            = RESOURCE_IN_STAGING_FILE;
569         new_lte->staging_file_name            = staging_file_name;
570         new_lte->lte_inode                    = inode;
571         random_hash(new_lte->hash);
572
573         if (stream_id == 0)
574                 inode->lte = new_lte;
575         else
576                 for (u16 i = 0; i < inode->num_ads; i++)
577                         if (inode->ads_entries[i].stream_id == stream_id)
578                                 inode->ads_entries[i].lte = new_lte;
579
580         lookup_table_insert(ctx->wim->lookup_table, new_lte);
581         list_add(&new_lte->staging_list, &ctx->staging_list);
582         *lte = new_lte;
583         return 0;
584 out_revert_fd_changes:
585         for (u16 i = 0, j = 0; j < new_lte->num_opened_fds; i++) {
586                 struct wimlib_fd *fd = inode->fds[i];
587                 if (fd && fd->stream_id == stream_id && fd->f_lte == new_lte) {
588                         fd->f_lte = old_lte;
589                         if (fd->staging_fd != -1) {
590                                 close(fd->staging_fd);
591                                 fd->staging_fd = -1;
592                         }
593                         j++;
594                 }
595         }
596         free_lookup_table_entry(new_lte);
597 out_delete_staging_file:
598         unlink(staging_file_name);
599         FREE(staging_file_name);
600         return ret;
601 }
602
603 /*
604  * Creates a randomly named staging directory and saves its name in the
605  * filesystem context structure.
606  */
607 static int make_staging_dir(struct wimfs_context *ctx, const char *user_prefix)
608 {
609         static const size_t random_suffix_len = 10;
610         static const char *common_suffix = ".staging";
611         static const size_t common_suffix_len = 8;
612
613         char *staging_dir_name = NULL;
614         size_t staging_dir_name_len;
615         size_t prefix_len;
616         const char *wim_basename;
617         char *real_user_prefix = NULL;
618         int ret;
619
620         if (user_prefix) {
621                 real_user_prefix = realpath(user_prefix, NULL);
622                 if (!real_user_prefix) {
623                         ERROR_WITH_ERRNO("Could not resolve `%s'",
624                                          real_user_prefix);
625                         ret = WIMLIB_ERR_NOTDIR;
626                         goto out;
627                 }
628                 wim_basename = path_basename(ctx->wim->filename);
629                 prefix_len = strlen(real_user_prefix) + 1 + strlen(wim_basename);
630         } else {
631                 prefix_len = strlen(ctx->wim->filename);
632         }
633
634         staging_dir_name_len = prefix_len + common_suffix_len + random_suffix_len;
635
636         staging_dir_name = MALLOC(staging_dir_name_len + 1);
637         if (!staging_dir_name) {
638                 ret = WIMLIB_ERR_NOMEM;
639                 goto out;
640         }
641
642         if (real_user_prefix)
643                 sprintf(staging_dir_name, "%s/%s", real_user_prefix, wim_basename);
644         else
645                 strcpy(staging_dir_name, ctx->wim->filename);
646
647         strcat(staging_dir_name, common_suffix);
648
649         randomize_char_array_with_alnum(staging_dir_name + prefix_len + common_suffix_len,
650                                         random_suffix_len);
651
652         staging_dir_name[staging_dir_name_len] = '\0';
653
654         if (mkdir(staging_dir_name, 0700) != 0) {
655                 ERROR_WITH_ERRNO("Failed to create temporary directory `%s'",
656                                  staging_dir_name);
657                 ret = WIMLIB_ERR_MKDIR;
658         } else {
659                 ret = 0;
660         }
661 out:
662         FREE(real_user_prefix);
663         if (ret == 0) {
664                 ctx->staging_dir_name = staging_dir_name;
665                 ctx->staging_dir_name_len = staging_dir_name_len;
666         } else {
667                 FREE(staging_dir_name);
668         }
669         return ret;
670 }
671
672 static int remove_file_or_directory(const char *fpath, const struct stat *sb,
673                                     int typeflag, struct FTW *ftwbuf)
674 {
675         if (remove(fpath) == 0)
676                 return 0;
677         else {
678                 ERROR_WITH_ERRNO("Cannot remove `%s'", fpath);
679                 return WIMLIB_ERR_DELETE_STAGING_DIR;
680         }
681 }
682
683 /*
684  * Deletes the staging directory and all the files contained in it.
685  */
686 static int delete_staging_dir(struct wimfs_context *ctx)
687 {
688         int ret;
689         ret = nftw(ctx->staging_dir_name, remove_file_or_directory,
690                    10, FTW_DEPTH);
691         FREE(ctx->staging_dir_name);
692         ctx->staging_dir_name = NULL;
693         return ret;
694 }
695
696 static void inode_update_lte_ptr(struct inode *inode,
697                                  struct lookup_table_entry *old_lte,
698                                  struct lookup_table_entry *new_lte)
699 {
700         if (inode->lte == old_lte) {
701                 inode->lte = new_lte;
702         } else {
703                 for (unsigned i = 0; i < inode->num_ads; i++) {
704                         if (inode->ads_entries[i].lte == old_lte) {
705                                 inode->ads_entries[i].lte = new_lte;
706                                 break;
707                         }
708                 }
709         }
710 }
711
712 static int update_lte_of_staging_file(struct lookup_table_entry *lte,
713                                       struct lookup_table *table)
714 {
715         struct lookup_table_entry *duplicate_lte;
716         int ret;
717         u8 hash[SHA1_HASH_SIZE];
718         struct stat stbuf;
719
720         ret = sha1sum(lte->staging_file_name, hash);
721         if (ret != 0)
722                 return ret;
723         lookup_table_unlink(table, lte);
724         duplicate_lte = __lookup_resource(table, hash);
725         if (duplicate_lte) {
726                 /* Merge duplicate lookup table entries */
727                 duplicate_lte->refcnt += lte->refcnt;
728                 inode_update_lte_ptr(lte->lte_inode, lte, duplicate_lte);
729                 free_lookup_table_entry(lte);
730         } else {
731                 if (stat(lte->staging_file_name, &stbuf) != 0) {
732                         ERROR_WITH_ERRNO("Failed to stat `%s'", lte->staging_file_name);
733                         return WIMLIB_ERR_STAT;
734                 }
735                 if (stbuf.st_size == 0) {
736                         /* Zero-length stream.  No lookup table entry needed. */
737                         inode_update_lte_ptr(lte->lte_inode, lte, NULL);
738                         free_lookup_table_entry(lte);
739                 } else {
740                         wimlib_assert(&lte->file_on_disk == &lte->staging_file_name);
741                         lte->resource_entry.original_size = stbuf.st_size;
742                         lte->resource_entry.size = stbuf.st_size;
743                         lte->resource_location = RESOURCE_IN_FILE_ON_DISK;
744                         lte->file_on_disk_fp = NULL;
745                         copy_hash(lte->hash, hash);
746                         lookup_table_insert(table, lte);
747                 }
748         }
749         return 0;
750 }
751
752 static int inode_close_fds(struct inode *inode)
753 {
754         u16 num_opened_fds = inode->num_opened_fds;
755         for (u16 i = 0, j = 0; j < num_opened_fds; i++) {
756                 struct wimlib_fd *fd = inode->fds[i];
757                 if (fd) {
758                         wimlib_assert(fd->f_inode == inode);
759                         int ret = close_wimlib_fd(fd);
760                         if (ret != 0)
761                                 return ret;
762                         j++;
763                 }
764         }
765         return 0;
766 }
767
768 /* Overwrites the WIM file, with changes saved. */
769 static int rebuild_wim(struct wimfs_context *ctx, int write_flags,
770                        wimlib_progress_func_t progress_func)
771 {
772         int ret;
773         struct lookup_table_entry *lte, *tmp;
774         WIMStruct *w = ctx->wim;
775
776         DEBUG("Closing all staging file descriptors.");
777         list_for_each_entry_safe(lte, tmp, &ctx->staging_list, staging_list) {
778                 ret = inode_close_fds(lte->lte_inode);
779                 if (ret != 0)
780                         return ret;
781         }
782
783         DEBUG("Calculating SHA1 checksums for all new staging files.");
784         list_for_each_entry(lte, &ctx->staging_list, staging_list) {
785                 ret = update_lte_of_staging_file(lte, w->lookup_table);
786                 if (ret != 0)
787                         return ret;
788         }
789
790         xml_update_image_info(w, w->current_image);
791         ret = wimlib_overwrite(w, write_flags, 0, progress_func);
792         if (ret != 0)
793                 ERROR("Failed to commit changes to mounted WIM image");
794         return ret;
795 }
796
797
798
799 /* Simple function that returns the concatenation of 2 strings. */
800 static char *strcat_dup(const char *s1, const char *s2, size_t max_len)
801 {
802         size_t len = strlen(s1) + strlen(s2);
803         if (len > max_len)
804                 len = max_len;
805         char *p = MALLOC(len + 1);
806         if (!p)
807                 return NULL;
808         snprintf(p, len + 1, "%s%s", s1, s2);
809         return p;
810 }
811
812 static int set_message_queue_names(struct wimfs_context *ctx,
813                                    const char *mount_dir)
814 {
815         static const char *u2d_prefix = "/wimlib-unmount-to-daemon-mq";
816         static const char *d2u_prefix = "/wimlib-daemon-to-unmount-mq";
817         char *dir_path;
818         char *p;
819         int ret;
820
821         dir_path = realpath(mount_dir, NULL);
822         if (!dir_path) {
823                 ERROR_WITH_ERRNO("Failed to resolve path \"%s\"", mount_dir);
824                 if (errno == ENOMEM)
825                         return WIMLIB_ERR_NOMEM;
826                 else
827                         return WIMLIB_ERR_NOTDIR;
828         }
829
830         p = dir_path;
831         while (*p) {
832                 if (*p == '/')
833                         *p = 0xff;
834                 p++;
835         }
836
837         ctx->unmount_to_daemon_mq_name = strcat_dup(u2d_prefix, dir_path,
838                                                     NAME_MAX);
839         if (!ctx->unmount_to_daemon_mq_name) {
840                 ret = WIMLIB_ERR_NOMEM;
841                 goto out_free_dir_path;
842         }
843         ctx->daemon_to_unmount_mq_name = strcat_dup(d2u_prefix, dir_path,
844                                                     NAME_MAX);
845         if (!ctx->daemon_to_unmount_mq_name) {
846                 ret = WIMLIB_ERR_NOMEM;
847                 goto out_free_unmount_to_daemon_mq_name;
848         }
849
850         ret = 0;
851         goto out_free_dir_path;
852 out_free_unmount_to_daemon_mq_name:
853         FREE(ctx->unmount_to_daemon_mq_name);
854         ctx->unmount_to_daemon_mq_name = NULL;
855 out_free_dir_path:
856         FREE(dir_path);
857         return ret;
858 }
859
860 static void free_message_queue_names(struct wimfs_context *ctx)
861 {
862         FREE(ctx->unmount_to_daemon_mq_name);
863         FREE(ctx->daemon_to_unmount_mq_name);
864         ctx->unmount_to_daemon_mq_name = NULL;
865         ctx->daemon_to_unmount_mq_name = NULL;
866 }
867
868 /*
869  * Opens two POSIX message queue: one for sending messages from the unmount
870  * process to the daemon process, and one to go the other way.  The names of the
871  * message queues, which must be system-wide unique, are be based on the mount
872  * point.
873  *
874  * @daemon specifies whether the calling process is the filesystem daemon or the
875  * unmount process.
876  */
877 static int open_message_queues(struct wimfs_context *ctx, bool daemon)
878 {
879         int unmount_to_daemon_mq_flags = O_WRONLY | O_CREAT;
880         int daemon_to_unmount_mq_flags = O_RDONLY | O_CREAT;
881
882         if (daemon)
883                 swap(unmount_to_daemon_mq_flags, daemon_to_unmount_mq_flags);
884
885         DEBUG("Opening message queue \"%s\"", ctx->unmount_to_daemon_mq_name);
886         ctx->unmount_to_daemon_mq = mq_open(ctx->unmount_to_daemon_mq_name,
887                                             unmount_to_daemon_mq_flags, 0700, NULL);
888
889         if (ctx->unmount_to_daemon_mq == (mqd_t)-1) {
890                 ERROR_WITH_ERRNO("mq_open()");
891                 return WIMLIB_ERR_MQUEUE;
892         }
893
894         DEBUG("Opening message queue \"%s\"", ctx->daemon_to_unmount_mq_name);
895         ctx->daemon_to_unmount_mq = mq_open(ctx->daemon_to_unmount_mq_name,
896                                             daemon_to_unmount_mq_flags, 0700, NULL);
897
898         if (ctx->daemon_to_unmount_mq == (mqd_t)-1) {
899                 ERROR_WITH_ERRNO("mq_open()");
900                 mq_close(ctx->unmount_to_daemon_mq);
901                 mq_unlink(ctx->unmount_to_daemon_mq_name);
902                 ctx->unmount_to_daemon_mq = (mqd_t)-1;
903                 return WIMLIB_ERR_MQUEUE;
904         }
905         return 0;
906 }
907
908 /* Try to determine the maximum message size of a message queue.  The return
909  * value is the maximum message size, or a guess of 8192 bytes if it cannot be
910  * determined. */
911 static long mq_get_msgsize(mqd_t mq)
912 {
913         static const char *msgsize_max_file = "/proc/sys/fs/mqueue/msgsize_max";
914         FILE *fp;
915         struct mq_attr attr;
916         long msgsize;
917
918         if (mq_getattr(mq, &attr) == 0) {
919                 msgsize = attr.mq_msgsize;
920         } else {
921                 ERROR_WITH_ERRNO("mq_getattr()");
922                 ERROR("Attempting to read %s", msgsize_max_file);
923                 fp = fopen(msgsize_max_file, "rb");
924                 if (fp) {
925                         if (fscanf(fp, "%ld", &msgsize) != 1) {
926                                 ERROR("Assuming message size of 8192");
927                                 msgsize = 8192;
928                         }
929                         fclose(fp);
930                 } else {
931                         ERROR_WITH_ERRNO("Failed to open the file `%s'",
932                                          msgsize_max_file);
933                         ERROR("Assuming message size of 8192");
934                         msgsize = 8192;
935                 }
936         }
937         return msgsize;
938 }
939
940 static int get_mailbox(mqd_t mq, long needed_msgsize, long *msgsize_ret,
941                        void **mailbox_ret)
942 {
943         long msgsize;
944         char *mailbox;
945
946         msgsize = mq_get_msgsize(mq);
947
948         if (msgsize < needed_msgsize) {
949                 ERROR("Message queue max size must be at least %ld!",
950                       needed_msgsize);
951                 return WIMLIB_ERR_MQUEUE;
952         }
953
954         mailbox = MALLOC(msgsize);
955         if (!mailbox) {
956                 ERROR("Failed to allocate %ld bytes for mailbox", msgsize);
957                 return WIMLIB_ERR_NOMEM;
958         }
959         *msgsize_ret = msgsize;
960         *mailbox_ret = mailbox;
961         return 0;
962 }
963
964 static void unlink_message_queues(struct wimfs_context *ctx)
965 {
966         mq_unlink(ctx->unmount_to_daemon_mq_name);
967         mq_unlink(ctx->daemon_to_unmount_mq_name);
968 }
969
970 /* Closes the message queues, which are allocated in static variables */
971 static void close_message_queues(struct wimfs_context *ctx)
972 {
973         DEBUG("Closing message queues");
974         mq_close(ctx->unmount_to_daemon_mq);
975         ctx->unmount_to_daemon_mq = (mqd_t)(-1);
976         mq_close(ctx->daemon_to_unmount_mq);
977         ctx->daemon_to_unmount_mq = (mqd_t)(-1);
978         unlink_message_queues(ctx);
979 }
980
981
982 struct unmount_msg_hdr {
983         u32 min_version;
984         u32 cur_version;
985         u32 msg_type;
986         u32 msg_size;
987 } PACKED;
988
989 struct msg_unmount_request {
990         struct unmount_msg_hdr hdr;
991         u32 unmount_flags;
992         u8 want_progress_messages;
993 } PACKED;
994
995 struct msg_daemon_info {
996         struct unmount_msg_hdr hdr;
997         pid_t daemon_pid;
998         u32 mount_flags;
999 } PACKED;
1000
1001 struct msg_unmount_finished {
1002         struct unmount_msg_hdr hdr;
1003         int32_t status;
1004 } PACKED;
1005
1006 struct msg_write_streams_progress {
1007         struct unmount_msg_hdr hdr;
1008         union wimlib_progress_info info;
1009 } PACKED;
1010
1011 enum {
1012         MSG_TYPE_UNMOUNT_REQUEST,
1013         MSG_TYPE_DAEMON_INFO,
1014         MSG_TYPE_WRITE_STREAMS_PROGRESS,
1015         MSG_TYPE_UNMOUNT_FINISHED,
1016         MSG_TYPE_MAX,
1017 };
1018
1019 struct msg_handler_context {
1020         int timeout_seconds;
1021         union {
1022                 struct {
1023                         pid_t daemon_pid;
1024                         int mount_flags;
1025                         int status;
1026                         wimlib_progress_func_t progress_func;
1027                 } unmount;
1028                 struct {
1029                         struct wimfs_context *wimfs_ctx;
1030                 } daemon;
1031         };
1032 };
1033
1034 static int send_unmount_request_msg(mqd_t mq, int unmount_flags,
1035                                     u8 want_progress_messages)
1036 {
1037         DEBUG("Sending unmount request msg");
1038         struct msg_unmount_request msg = {
1039                 .hdr = {
1040                         .min_version = WIMLIB_MAKEVERSION(1, 2, 0),
1041                         .cur_version = WIMLIB_VERSION_CODE,
1042                         .msg_type    = MSG_TYPE_UNMOUNT_REQUEST,
1043                         .msg_size    = sizeof(msg),
1044                 },
1045                 .unmount_flags = unmount_flags,
1046                 .want_progress_messages = want_progress_messages,
1047         };
1048
1049         if (mq_send(mq, (void*)&msg, sizeof(msg), 1)) {
1050                 ERROR_WITH_ERRNO("Failed to communicate with filesystem daemon");
1051                 return WIMLIB_ERR_MQUEUE;
1052         }
1053         return 0;
1054 }
1055
1056 static int send_daemon_info_msg(mqd_t mq, pid_t pid, int mount_flags)
1057 {
1058         DEBUG("Sending daemon info msg (pid = %d, mount_flags=%x)",
1059               pid, mount_flags);
1060
1061         struct msg_daemon_info msg = {
1062                 .hdr = {
1063                         .min_version = WIMLIB_MAKEVERSION(1, 2, 0),
1064                         .cur_version = WIMLIB_VERSION_CODE,
1065                         .msg_type = MSG_TYPE_DAEMON_INFO,
1066                         .msg_size = sizeof(msg),
1067                 },
1068                 .daemon_pid = pid,
1069                 .mount_flags = mount_flags,
1070         };
1071         if (mq_send(mq, (void*)&msg, sizeof(msg), 1)) {
1072                 ERROR_WITH_ERRNO("Failed to send daemon info to unmount process");
1073                 return WIMLIB_ERR_MQUEUE;
1074         }
1075         return 0;
1076 }
1077
1078 static void send_unmount_finished_msg(mqd_t mq, int status)
1079 {
1080         DEBUG("Sending unmount finished msg");
1081         struct msg_unmount_finished msg = {
1082                 .hdr = {
1083                         .min_version = WIMLIB_MAKEVERSION(1, 2, 0),
1084                         .cur_version = WIMLIB_VERSION_CODE,
1085                         .msg_type = MSG_TYPE_UNMOUNT_FINISHED,
1086                         .msg_size = sizeof(msg),
1087                 },
1088                 .status = status,
1089         };
1090         if (mq_send(mq, (void*)&msg, sizeof(msg), 1))
1091                 ERROR_WITH_ERRNO("Failed to send status to unmount process");
1092 }
1093
1094 static int unmount_progress_func(enum wimlib_progress_msg msg,
1095                                  const union wimlib_progress_info *info)
1096 {
1097         if (msg == WIMLIB_PROGRESS_MSG_WRITE_STREAMS) {
1098                 struct msg_write_streams_progress msg = {
1099                         .hdr = {
1100                                 .min_version = WIMLIB_MAKEVERSION(1, 2, 0),
1101                                 .cur_version = WIMLIB_VERSION_CODE,
1102                                 .msg_type = MSG_TYPE_WRITE_STREAMS_PROGRESS,
1103                                 .msg_size = sizeof(msg),
1104                         },
1105                         .info = *info,
1106                 };
1107                 if (mq_send(wimfs_get_context()->daemon_to_unmount_mq,
1108                             (void*)&msg, sizeof(msg), 1))
1109                 {
1110                         ERROR_WITH_ERRNO("Failed to send progress information "
1111                                          "to unmount process");
1112                 }
1113         }
1114         return 0;
1115 }
1116
1117 static int msg_unmount_request_handler(const void *_msg,
1118                                        struct msg_handler_context *handler_ctx)
1119 {
1120         const struct msg_unmount_request *msg;
1121         struct wimfs_context *wimfs_ctx;
1122         int status = 0;
1123         int ret;
1124         int unmount_flags;
1125         wimlib_progress_func_t progress_func;
1126
1127         DEBUG("Handling unmount request msg");
1128
1129         msg = _msg;
1130         wimfs_ctx = handler_ctx->daemon.wimfs_ctx;
1131
1132         if (msg->hdr.msg_size < sizeof(*msg)) {
1133                 status = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1134                 goto out;
1135         }
1136
1137         unmount_flags = msg->unmount_flags;
1138         if (msg->want_progress_messages)
1139                 progress_func = unmount_progress_func;
1140         else
1141                 progress_func = NULL;
1142
1143         ret = send_daemon_info_msg(wimfs_ctx->daemon_to_unmount_mq, getpid(),
1144                                    wimfs_ctx->mount_flags);
1145         if (ret != 0) {
1146                 status = ret;
1147                 goto out;
1148         }
1149
1150         if (wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
1151                 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_COMMIT) {
1152                         int write_flags = 0;
1153                         if (unmount_flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY)
1154                                 write_flags |= WIMLIB_WRITE_FLAG_CHECK_INTEGRITY;
1155                         if (unmount_flags & WIMLIB_UNMOUNT_FLAG_REBUILD)
1156                                 write_flags |= WIMLIB_WRITE_FLAG_REBUILD;
1157                         if (unmount_flags & WIMLIB_UNMOUNT_FLAG_RECOMPRESS)
1158                                 write_flags |= WIMLIB_WRITE_FLAG_RECOMPRESS;
1159                         status = rebuild_wim(wimfs_ctx, write_flags,
1160                                              progress_func);
1161                 }
1162         } else {
1163                 DEBUG("Read-only mount");
1164                 status = 0;
1165         }
1166
1167 out:
1168         if (wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
1169                 ret = delete_staging_dir(wimfs_ctx);
1170                 if (ret != 0) {
1171                         ERROR("Failed to delete the staging directory");
1172                         if (status == 0)
1173                                 status = ret;
1174                 }
1175         }
1176         send_unmount_finished_msg(wimfs_ctx->daemon_to_unmount_mq, status);
1177         return MSG_BREAK_LOOP;
1178 }
1179
1180 static int msg_daemon_info_handler(const void *_msg,
1181                                    struct msg_handler_context *handler_ctx)
1182 {
1183         const struct msg_daemon_info *msg = _msg;
1184         DEBUG("Handling daemon info msg");
1185         if (msg->hdr.msg_size < sizeof(*msg))
1186                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1187         handler_ctx->unmount.daemon_pid = msg->daemon_pid;
1188         handler_ctx->unmount.mount_flags = msg->mount_flags;
1189         handler_ctx->timeout_seconds = 1;
1190         DEBUG("pid of daemon is %d; mount flags were %#x",
1191               handler_ctx->unmount.daemon_pid,
1192               handler_ctx->unmount.mount_flags);
1193         return 0;
1194 }
1195
1196 static int msg_write_streams_progress_handler(const void *_msg,
1197                                               struct msg_handler_context *handler_ctx)
1198 {
1199         const struct msg_write_streams_progress *msg = _msg;
1200         if (msg->hdr.msg_size < sizeof(*msg))
1201                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1202         if (handler_ctx->unmount.progress_func) {
1203                 handler_ctx->unmount.progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS,
1204                                                    &msg->info);
1205         }
1206         return 0;
1207 }
1208
1209 static int msg_unmount_finished_handler(const void *_msg,
1210                                         struct msg_handler_context *handler_ctx)
1211 {
1212         const struct msg_unmount_finished *msg = _msg;
1213         DEBUG("Handling unmount finished message");
1214         if (msg->hdr.msg_size < sizeof(*msg))
1215                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1216         handler_ctx->unmount.status = msg->status;
1217         DEBUG("status is %d", handler_ctx->unmount.status);
1218         return MSG_BREAK_LOOP;
1219 }
1220
1221 static int unmount_timed_out_cb(struct msg_handler_context *handler_ctx)
1222 {
1223         if (handler_ctx->unmount.daemon_pid == 0) {
1224                 goto out_crashed;
1225         } else {
1226                 kill(handler_ctx->unmount.daemon_pid, 0);
1227                 if (errno == ESRCH) {
1228                         goto out_crashed;
1229                 } else {
1230                         DEBUG("Filesystem daemon is still alive... "
1231                               "Waiting another %d seconds\n",
1232                               handler_ctx->timeout_seconds);
1233                         return 0;
1234                 }
1235         }
1236 out_crashed:
1237         ERROR("The filesystem daemon has crashed!  Changes to the "
1238               "WIM may not have been commited.");
1239         return WIMLIB_ERR_FILESYSTEM_DAEMON_CRASHED;
1240 }
1241
1242 static int daemon_timed_out_cb(struct msg_handler_context *handler_ctx)
1243 {
1244         ERROR("Timed out waiting for unmount request! "
1245               "Changes to the mounted WIM will not be committed.");
1246         return WIMLIB_ERR_TIMEOUT;
1247 }
1248
1249 typedef int (*msg_handler_t)(const void *_msg,
1250                              struct msg_handler_context *handler_ctx);
1251
1252 struct msg_handler_callbacks {
1253         int (*timed_out)(struct msg_handler_context *);
1254         msg_handler_t msg_handlers[MSG_TYPE_MAX];
1255 };
1256
1257 static const struct msg_handler_callbacks unmount_msg_handler_callbacks = {
1258         .timed_out = unmount_timed_out_cb,
1259         .msg_handlers = {
1260                 [MSG_TYPE_DAEMON_INFO] = msg_daemon_info_handler,
1261                 [MSG_TYPE_WRITE_STREAMS_PROGRESS] = msg_write_streams_progress_handler,
1262                 [MSG_TYPE_UNMOUNT_FINISHED] = msg_unmount_finished_handler,
1263         },
1264 };
1265
1266 static const struct msg_handler_callbacks daemon_msg_handler_callbacks = {
1267         .timed_out = daemon_timed_out_cb,
1268         .msg_handlers = {
1269                 [MSG_TYPE_UNMOUNT_REQUEST] = msg_unmount_request_handler,
1270         },
1271 };
1272
1273 static int receive_message(mqd_t mq, struct msg_handler_context *handler_ctx,
1274                            const msg_handler_t msg_handlers[],
1275                            long mailbox_size, void *mailbox)
1276 {
1277         struct timeval now;
1278         struct timespec timeout;
1279         ssize_t bytes_received;
1280         struct unmount_msg_hdr *hdr;
1281         int ret;
1282
1283         gettimeofday(&now, NULL);
1284         timeout.tv_sec = now.tv_sec + handler_ctx->timeout_seconds;
1285         timeout.tv_nsec = now.tv_usec * 1000;
1286
1287         bytes_received = mq_timedreceive(mq, mailbox,
1288                                          mailbox_size, NULL, &timeout);
1289         hdr = mailbox;
1290         if (bytes_received == -1) {
1291                 if (errno == ETIMEDOUT) {
1292                         ret = WIMLIB_ERR_TIMEOUT;
1293                 } else {
1294                         ERROR_WITH_ERRNO("mq_timedreceive()");
1295                         ret = WIMLIB_ERR_MQUEUE;
1296                 }
1297         } else if (bytes_received < sizeof(*hdr) ||
1298                    bytes_received != hdr->msg_size) {
1299                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1300         } else if (WIMLIB_VERSION_CODE < hdr->min_version) {
1301                 /*ERROR("Cannot understand the received message. "*/
1302                       /*"Please upgrade wimlib to at least v%d.%d.%d",*/
1303                       /*WIMLIB_GET_MAJOR_VERSION(hdr->min_version),*/
1304                       /*WIMLIB_GET_MINOR_VERSION(hdr->min_version),*/
1305                       /*WIMLIB_GET_PATCH_VERSION(hdr->min_version));*/
1306                 ret = MSG_VERSION_TOO_HIGH;
1307         } else if (hdr->msg_type >= MSG_TYPE_MAX) {
1308                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1309         } else if (msg_handlers[hdr->msg_type] == NULL) {
1310                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1311         } else {
1312                 ret = msg_handlers[hdr->msg_type](mailbox, handler_ctx);
1313         }
1314         return ret;
1315 }
1316
1317 static int message_loop(mqd_t mq,
1318                         const struct msg_handler_callbacks *callbacks,
1319                         struct msg_handler_context *handler_ctx)
1320 {
1321         static const size_t MAX_MSG_SIZE = 512;
1322         long msgsize;
1323         void *mailbox;
1324         int ret;
1325
1326         DEBUG("Entering message loop");
1327
1328         ret = get_mailbox(mq, MAX_MSG_SIZE, &msgsize, &mailbox);
1329         if (ret != 0)
1330                 return ret;
1331         while (1) {
1332                 ret = receive_message(mq, handler_ctx,
1333                                       callbacks->msg_handlers,
1334                                       msgsize, mailbox);
1335                 if (ret == 0 || ret == MSG_VERSION_TOO_HIGH) {
1336                         continue;
1337                 } else if (ret == MSG_BREAK_LOOP) {
1338                         ret = 0;
1339                         break;
1340                 } else if (ret == WIMLIB_ERR_TIMEOUT) {
1341                         if (callbacks->timed_out)
1342                                 ret = callbacks->timed_out(handler_ctx);
1343                         if (ret == 0)
1344                                 continue;
1345                         else
1346                                 break;
1347                 } else {
1348                         ERROR_WITH_ERRNO("Error communicating with "
1349                                          "filesystem daemon");
1350                         break;
1351                 }
1352         }
1353         FREE(mailbox);
1354         DEBUG("Exiting message loop");
1355         return ret;
1356 }
1357
1358 /* Execute `fusermount -u', which is installed setuid root, to unmount the WIM.
1359  *
1360  * FUSE does not yet implement synchronous unmounts.  This means that fusermount
1361  * -u will return before the filesystem daemon returns from wimfs_destroy().
1362  *  This is partly what we want, because we need to send a message from this
1363  *  process to the filesystem daemon telling whether --commit was specified or
1364  *  not.  However, after that, the unmount process must wait for the filesystem
1365  *  daemon to finish writing the WIM file.
1366  */
1367 static int execute_fusermount(const char *dir)
1368 {
1369         pid_t pid;
1370         int ret;
1371         int status;
1372
1373         pid = fork();
1374         if (pid == -1) {
1375                 ERROR_WITH_ERRNO("Failed to fork()");
1376                 return WIMLIB_ERR_FORK;
1377         }
1378         if (pid == 0) {
1379                 /* Child */
1380                 execlp("fusermount", "fusermount", "-u", dir, NULL);
1381                 ERROR_WITH_ERRNO("Failed to execute `fusermount'");
1382                 exit(WIMLIB_ERR_FUSERMOUNT);
1383         }
1384
1385         /* Parent */
1386         ret = wait(&status);
1387         if (ret == -1) {
1388                 ERROR_WITH_ERRNO("Failed to wait for fusermount process to "
1389                                  "terminate");
1390                 return WIMLIB_ERR_FUSERMOUNT;
1391         }
1392
1393         if (status != 0) {
1394                 if (status == WIMLIB_ERR_FUSERMOUNT)
1395                         ERROR("Could not find the `fusermount' program");
1396                 else
1397                         ERROR("fusermount exited with status %d", status);
1398
1399                 /* Try again, but with the `umount' program.  This is required
1400                  * on other FUSE implementations such as FreeBSD's that do not
1401                  * have a `fusermount' program. */
1402
1403                 pid = fork();
1404                 if (pid == -1) {
1405                         ERROR_WITH_ERRNO("Failed to fork()");
1406                         return WIMLIB_ERR_FORK;
1407                 }
1408                 if (pid == 0) {
1409                         /* Child */
1410                         execlp("umount", "umount", dir, NULL);
1411                         ERROR_WITH_ERRNO("Failed to execute `umount'");
1412                         exit(WIMLIB_ERR_FUSERMOUNT);
1413                 }
1414
1415                 /* Parent */
1416                 ret = wait(&status);
1417                 if (ret == -1) {
1418                         ERROR_WITH_ERRNO("Failed to wait for `umount' process to "
1419                                          "terminate");
1420                         return WIMLIB_ERR_FUSERMOUNT;
1421                 }
1422                 if (status != 0) {
1423                         ERROR("`umount' exited with failure status");
1424                         return WIMLIB_ERR_FUSERMOUNT;
1425                 }
1426         }
1427         return 0;
1428 }
1429
1430 static int wimfs_access(const char *path, int mask)
1431 {
1432         /* Permissions not implemented */
1433         return 0;
1434 }
1435
1436 static int wimfs_chmod(const char *path, mode_t mask)
1437 {
1438         struct dentry *dentry;
1439         struct wimfs_context *ctx = wimfs_get_context();
1440         struct inode *inode;
1441         struct stat stbuf;
1442         int ret;
1443
1444         ret = lookup_resource(ctx->wim, path,
1445                               get_lookup_flags(ctx) | LOOKUP_FLAG_DIRECTORY_OK,
1446                               &dentry, NULL, NULL);
1447         if (ret != 0)
1448                 return ret;
1449         inode = dentry->d_inode;
1450         inode_to_stbuf(inode, NULL, &stbuf);
1451         if (mask == stbuf.st_mode)
1452                 return 0;
1453         else
1454                 return -EPERM;
1455 }
1456
1457 /* Called when the filesystem is unmounted. */
1458 static void wimfs_destroy(void *p)
1459 {
1460         struct wimfs_context *wimfs_ctx = wimfs_get_context();
1461         if (open_message_queues(wimfs_ctx, true) == 0) {
1462                 struct msg_handler_context handler_ctx = {
1463                         .timeout_seconds = 5,
1464                         .daemon = {
1465                                 .wimfs_ctx = wimfs_ctx,
1466                         },
1467                 };
1468                 message_loop(wimfs_ctx->unmount_to_daemon_mq,
1469                              &daemon_msg_handler_callbacks,
1470                              &handler_ctx);
1471                 close_message_queues(wimfs_ctx);
1472         }
1473 }
1474
1475 #if 0
1476 static int wimfs_fallocate(const char *path, int mode,
1477                            off_t offset, off_t len, struct fuse_file_info *fi)
1478 {
1479         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1480         wimlib_assert(fd->staging_fd != -1);
1481         return fallocate(fd->staging_fd, mode, offset, len);
1482 }
1483
1484 #endif
1485
1486 static int wimfs_fgetattr(const char *path, struct stat *stbuf,
1487                           struct fuse_file_info *fi)
1488 {
1489         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1490         return inode_to_stbuf(fd->f_inode, fd->f_lte, stbuf);
1491 }
1492
1493 static int wimfs_ftruncate(const char *path, off_t size,
1494                            struct fuse_file_info *fi)
1495 {
1496         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1497         int ret = ftruncate(fd->staging_fd, size);
1498         if (ret != 0)
1499                 return -errno;
1500         if (fd->f_lte && size < fd->f_lte->resource_entry.original_size)
1501                 fd->f_lte->resource_entry.original_size = size;
1502         return 0;
1503 }
1504
1505 /*
1506  * Fills in a `struct stat' that corresponds to a file or directory in the WIM.
1507  */
1508 static int wimfs_getattr(const char *path, struct stat *stbuf)
1509 {
1510         struct dentry *dentry;
1511         struct lookup_table_entry *lte;
1512         int ret;
1513         struct wimfs_context *ctx = wimfs_get_context();
1514
1515         ret = lookup_resource(ctx->wim, path,
1516                               get_lookup_flags(ctx) | LOOKUP_FLAG_DIRECTORY_OK,
1517                               &dentry, &lte, NULL);
1518         if (ret != 0)
1519                 return ret;
1520         return inode_to_stbuf(dentry->d_inode, lte, stbuf);
1521 }
1522
1523 #ifdef ENABLE_XATTR
1524 /* Read an alternate data stream through the XATTR interface, or get its size */
1525 static int wimfs_getxattr(const char *path, const char *name, char *value,
1526                           size_t size)
1527 {
1528         int ret;
1529         struct inode *inode;
1530         struct ads_entry *ads_entry;
1531         size_t res_size;
1532         struct lookup_table_entry *lte;
1533         struct wimfs_context *ctx = wimfs_get_context();
1534
1535         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1536                 return -ENOTSUP;
1537
1538         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
1539                 return -ENOATTR;
1540         name += 5;
1541
1542         inode = wim_pathname_to_inode(ctx->wim, path);
1543         if (!inode)
1544                 return -ENOENT;
1545
1546         ads_entry = inode_get_ads_entry(inode, name, NULL);
1547         if (!ads_entry)
1548                 return -ENOATTR;
1549
1550         lte = ads_entry->lte;
1551         res_size = wim_resource_size(lte);
1552
1553         if (size == 0)
1554                 return res_size;
1555
1556         if (res_size > size)
1557                 return -ERANGE;
1558
1559         ret = read_full_wim_resource(lte, (u8*)value,
1560                                      WIMLIB_RESOURCE_FLAG_MULTITHREADED);
1561         if (ret != 0)
1562                 return -EIO;
1563
1564         return res_size;
1565 }
1566 #endif
1567
1568 /* Create a hard link */
1569 static int wimfs_link(const char *to, const char *from)
1570 {
1571         struct dentry *from_dentry, *from_dentry_parent;
1572         const char *link_name;
1573         struct inode *inode;
1574         struct lookup_table_entry *lte;
1575         WIMStruct *w = wimfs_get_WIMStruct();
1576         u16 i;
1577
1578         inode = wim_pathname_to_inode(w, to);
1579         if (!inode)
1580                 return -ENOENT;
1581
1582         if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT)
1583                 return -EEXIST;
1584
1585         if (inode->attributes & FILE_ATTRIBUTE_DIRECTORY)
1586                 return -EPERM;
1587
1588         from_dentry_parent = get_parent_dentry(w, from);
1589         if (!from_dentry_parent)
1590                 return -ENOENT;
1591         if (!dentry_is_directory(from_dentry_parent))
1592                 return -ENOTDIR;
1593
1594         link_name = path_basename(from);
1595         if (get_dentry_child_with_name(from_dentry_parent, link_name))
1596                 return -EEXIST;
1597         from_dentry = new_dentry(link_name);
1598         if (!from_dentry)
1599                 return -ENOMEM;
1600
1601         inode_add_dentry(from_dentry, inode);
1602         from_dentry->d_inode = inode;
1603         inode->link_count++;
1604
1605         for (i = 0; i <= inode->num_ads; i++) {
1606                 lte = inode_stream_lte_resolved(inode, i);
1607                 if (lte)
1608                         lte->refcnt++;
1609         }
1610         dentry_add_child(from_dentry_parent, from_dentry);
1611         return 0;
1612 }
1613
1614 #ifdef ENABLE_XATTR
1615 static int wimfs_listxattr(const char *path, char *list, size_t size)
1616 {
1617         size_t needed_size;
1618         struct inode *inode;
1619         struct wimfs_context *ctx = wimfs_get_context();
1620         u16 i;
1621         char *p;
1622
1623         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1624                 return -ENOTSUP;
1625
1626         /* List alternate data streams, or get the list size */
1627
1628         inode = wim_pathname_to_inode(ctx->wim, path);
1629         if (!inode)
1630                 return -ENOENT;
1631
1632         if (size == 0) {
1633                 needed_size = 0;
1634                 for (i = 0; i < inode->num_ads; i++)
1635                         needed_size += inode->ads_entries[i].stream_name_utf8_len + 6;
1636                 return needed_size;
1637         } else {
1638                 p = list;
1639                 for (i = 0; i < inode->num_ads; i++) {
1640                         needed_size = inode->ads_entries[i].stream_name_utf8_len + 6;
1641                         if (needed_size > size)
1642                                 return -ERANGE;
1643                         p += sprintf(p, "user.%s",
1644                                      inode->ads_entries[i].stream_name_utf8) + 1;
1645                         size -= needed_size;
1646                 }
1647                 return p - list;
1648         }
1649 }
1650 #endif
1651
1652
1653 /* Create a directory in the WIM.
1654  * @mode is currently ignored.  */
1655 static int wimfs_mkdir(const char *path, mode_t mode)
1656 {
1657         struct dentry *dentry;
1658         int ret;
1659
1660         ret = create_dentry(wimfs_get_context(), path, &dentry);
1661         if (ret == 0)
1662                 dentry->d_inode->attributes = FILE_ATTRIBUTE_DIRECTORY;
1663         return ret;
1664 }
1665
1666 /* Create a regular file in the WIM.
1667  * @mode is currently ignored.  */
1668 static int wimfs_mknod(const char *path, mode_t mode, dev_t rdev)
1669 {
1670         const char *stream_name;
1671         struct wimfs_context *ctx = wimfs_get_context();
1672         if ((ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
1673              && (stream_name = path_stream_name(path))) {
1674                 /* Make an alternate data stream */
1675                 struct ads_entry *new_entry;
1676                 struct inode *inode;
1677
1678                 char *p = (char*)stream_name - 1;
1679                 wimlib_assert(*p == ':');
1680                 *p = '\0';
1681
1682                 inode = wim_pathname_to_inode(ctx->wim, path);
1683                 if (!inode)
1684                         return -ENOENT;
1685                 if (inode->attributes &
1686                     (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY))
1687                         return -ENOENT;
1688                 if (inode_get_ads_entry(inode, stream_name, NULL))
1689                         return -EEXIST;
1690                 new_entry = inode_add_ads(inode, stream_name);
1691                 if (!new_entry)
1692                         return -ENOMEM;
1693                 return 0;
1694         } else {
1695                 struct dentry *dentry;
1696                 int ret;
1697
1698                 /* Make a normal file (not an alternate data stream) */
1699                 ret = create_dentry(ctx, path, &dentry);
1700                 if (ret == 0)
1701                         dentry->d_inode->attributes = FILE_ATTRIBUTE_NORMAL;
1702                 return ret;
1703         }
1704 }
1705
1706
1707 /* Open a file.  */
1708 static int wimfs_open(const char *path, struct fuse_file_info *fi)
1709 {
1710         struct dentry *dentry;
1711         struct lookup_table_entry *lte;
1712         int ret;
1713         struct wimlib_fd *fd;
1714         struct inode *inode;
1715         u16 stream_idx;
1716         u32 stream_id;
1717         struct wimfs_context *ctx = wimfs_get_context();
1718
1719         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
1720                               &dentry, &lte, &stream_idx);
1721         if (ret != 0)
1722                 return ret;
1723
1724         inode = dentry->d_inode;
1725
1726         if (stream_idx == 0)
1727                 stream_id = 0;
1728         else
1729                 stream_id = inode->ads_entries[stream_idx - 1].stream_id;
1730
1731         /* The file resource may be in the staging directory (read-write mounts
1732          * only) or in the WIM.  If it's in the staging directory, we need to
1733          * open a native file descriptor for the corresponding file.  Otherwise,
1734          * we can read the file resource directly from the WIM file if we are
1735          * opening it read-only, but we need to extract the resource to the
1736          * staging directory if we are opening it writable. */
1737
1738         if (flags_writable(fi->flags) &&
1739             (!lte || lte->resource_location != RESOURCE_IN_STAGING_FILE)) {
1740                 u64 size = (lte) ? wim_resource_size(lte) : 0;
1741                 ret = extract_resource_to_staging_dir(inode, stream_id,
1742                                                       &lte, size, ctx);
1743                 if (ret != 0)
1744                         return ret;
1745         }
1746
1747         ret = alloc_wimlib_fd(inode, stream_id, lte, &fd,
1748                               wimfs_ctx_readonly(ctx));
1749         if (ret != 0)
1750                 return ret;
1751
1752         if (lte && lte->resource_location == RESOURCE_IN_STAGING_FILE) {
1753                 fd->staging_fd = open(lte->staging_file_name, fi->flags);
1754                 if (fd->staging_fd == -1) {
1755                         int errno_save = errno;
1756                         close_wimlib_fd(fd);
1757                         return -errno_save;
1758                 }
1759         }
1760         fi->fh = (uintptr_t)fd;
1761         return 0;
1762 }
1763
1764 /* Opens a directory. */
1765 static int wimfs_opendir(const char *path, struct fuse_file_info *fi)
1766 {
1767         struct inode *inode;
1768         int ret;
1769         struct wimlib_fd *fd = NULL;
1770         struct wimfs_context *ctx = wimfs_get_context();
1771         WIMStruct *w = ctx->wim;
1772
1773         inode = wim_pathname_to_inode(w, path);
1774         if (!inode)
1775                 return -ENOENT;
1776         if (!inode_is_directory(inode))
1777                 return -ENOTDIR;
1778         ret = alloc_wimlib_fd(inode, 0, NULL, &fd, wimfs_ctx_readonly(ctx));
1779         fi->fh = (uintptr_t)fd;
1780         return ret;
1781 }
1782
1783
1784 /*
1785  * Read data from a file in the WIM or in the staging directory.
1786  */
1787 static int wimfs_read(const char *path, char *buf, size_t size,
1788                       off_t offset, struct fuse_file_info *fi)
1789 {
1790         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1791         ssize_t ret;
1792
1793         if (!fd)
1794                 return -EBADF;
1795
1796         if (!fd->f_lte) /* Empty stream with no lookup table entry */
1797                 return 0;
1798
1799         if (fd->f_lte->resource_location == RESOURCE_IN_STAGING_FILE) {
1800                 /* Read from staging file */
1801
1802                 wimlib_assert(fd->f_lte->staging_file_name);
1803                 wimlib_assert(fd->staging_fd != -1);
1804
1805                 DEBUG("Seek to offset %zu", offset);
1806
1807                 if (lseek(fd->staging_fd, offset, SEEK_SET) == -1)
1808                         return -errno;
1809                 ret = read(fd->staging_fd, buf, size);
1810                 if (ret == -1)
1811                         return -errno;
1812                 return ret;
1813         } else {
1814                 /* Read from WIM */
1815                 u64 res_size = wim_resource_size(fd->f_lte);
1816                 if (offset > res_size)
1817                         return -EOVERFLOW;
1818                 size = min(size, res_size - offset);
1819                 if (read_wim_resource(fd->f_lte, (u8*)buf,
1820                                       size, offset,
1821                                       WIMLIB_RESOURCE_FLAG_MULTITHREADED) != 0)
1822                         return -EIO;
1823                 return size;
1824         }
1825 }
1826
1827 struct fill_params {
1828         void *buf;
1829         fuse_fill_dir_t filler;
1830 };
1831
1832 static int dentry_fuse_fill(struct dentry *dentry, void *arg)
1833 {
1834         struct fill_params *fill_params = arg;
1835         return fill_params->filler(fill_params->buf, dentry->file_name_utf8,
1836                                    NULL, 0);
1837 }
1838
1839 /* Fills in the entries of the directory specified by @path using the
1840  * FUSE-provided function @filler.  */
1841 static int wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
1842                          off_t offset, struct fuse_file_info *fi)
1843 {
1844         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1845         struct inode *inode;
1846
1847         if (!fd)
1848                 return -EBADF;
1849
1850         inode = fd->f_inode;
1851
1852         struct fill_params fill_params = {
1853                 .buf = buf,
1854                 .filler = filler,
1855         };
1856
1857         filler(buf, ".", NULL, 0);
1858         filler(buf, "..", NULL, 0);
1859
1860         return for_dentry_in_rbtree(inode->children.rb_node,
1861                                     dentry_fuse_fill, &fill_params);
1862 }
1863
1864
1865 static int wimfs_readlink(const char *path, char *buf, size_t buf_len)
1866 {
1867         struct wimfs_context *ctx = wimfs_get_context();
1868         struct inode *inode = wim_pathname_to_inode(ctx->wim, path);
1869         int ret;
1870         if (!inode)
1871                 return -ENOENT;
1872         if (!inode_is_symlink(inode))
1873                 return -EINVAL;
1874
1875         ret = inode_readlink(inode, buf, buf_len, ctx->wim,
1876                              WIMLIB_RESOURCE_FLAG_MULTITHREADED);
1877         if (ret > 0)
1878                 ret = 0;
1879         return ret;
1880 }
1881
1882 /* Close a file. */
1883 static int wimfs_release(const char *path, struct fuse_file_info *fi)
1884 {
1885         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1886         return close_wimlib_fd(fd);
1887 }
1888
1889 /* Close a directory */
1890 static int wimfs_releasedir(const char *path, struct fuse_file_info *fi)
1891 {
1892         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1893         return close_wimlib_fd(fd);
1894 }
1895
1896 #ifdef ENABLE_XATTR
1897 /* Remove an alternate data stream through the XATTR interface */
1898 static int wimfs_removexattr(const char *path, const char *name)
1899 {
1900         struct inode *inode;
1901         struct ads_entry *ads_entry;
1902         u16 ads_idx;
1903         struct wimfs_context *ctx = wimfs_get_context();
1904
1905         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1906                 return -ENOTSUP;
1907
1908         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
1909                 return -ENOATTR;
1910         name += 5;
1911
1912         inode = wim_pathname_to_inode(ctx->wim, path);
1913         if (!inode)
1914                 return -ENOENT;
1915
1916         ads_entry = inode_get_ads_entry(inode, name, &ads_idx);
1917         if (!ads_entry)
1918                 return -ENOATTR;
1919         inode_remove_ads(inode, ads_idx, ctx->wim->lookup_table);
1920         return 0;
1921 }
1922 #endif
1923
1924 /* Renames a file or directory.  See rename (3) */
1925 static int wimfs_rename(const char *from, const char *to)
1926 {
1927         struct dentry *src;
1928         struct dentry *dst;
1929         struct dentry *parent_of_dst;
1930         char *file_name_utf16 = NULL, *file_name_utf8 = NULL;
1931         u16 file_name_utf16_len, file_name_utf8_len;
1932         WIMStruct *w = wimfs_get_WIMStruct();
1933         int ret;
1934
1935         /* This rename() implementation currently only supports actual files
1936          * (not alternate data streams) */
1937
1938         src = get_dentry(w, from);
1939         if (!src)
1940                 return -ENOENT;
1941
1942         dst = get_dentry(w, to);
1943
1944         ret = get_names(&file_name_utf16, &file_name_utf8,
1945                         &file_name_utf16_len, &file_name_utf8_len,
1946                         path_basename(to));
1947         if (ret != 0)
1948                 return -ENOMEM;
1949
1950         if (dst) {
1951                 /* Destination file exists */
1952
1953                 if (src == dst) /* Same file */
1954                         return 0;
1955
1956                 if (!dentry_is_directory(src)) {
1957                         /* Cannot rename non-directory to directory. */
1958                         if (dentry_is_directory(dst))
1959                                 return -EISDIR;
1960                 } else {
1961                         /* Cannot rename directory to a non-directory or a non-empty
1962                          * directory */
1963                         if (!dentry_is_directory(dst))
1964                                 return -ENOTDIR;
1965                         if (inode_has_children(dst->d_inode))
1966                                 return -ENOTEMPTY;
1967                 }
1968                 parent_of_dst = dst->parent;
1969                 remove_dentry(dst, w->lookup_table);
1970         } else {
1971                 /* Destination does not exist */
1972                 parent_of_dst = get_parent_dentry(w, to);
1973                 if (!parent_of_dst)
1974                         return -ENOENT;
1975
1976                 if (!dentry_is_directory(parent_of_dst))
1977                         return -ENOTDIR;
1978         }
1979
1980         FREE(src->file_name);
1981         FREE(src->file_name_utf8);
1982         src->file_name          = file_name_utf16;
1983         src->file_name_utf8     = file_name_utf8;
1984         src->file_name_len      = file_name_utf16_len;
1985         src->file_name_utf8_len = file_name_utf8_len;
1986
1987         unlink_dentry(src);
1988         dentry_add_child(parent_of_dst, src);
1989         return 0;
1990 }
1991
1992 /* Remove a directory */
1993 static int wimfs_rmdir(const char *path)
1994 {
1995         struct dentry *dentry;
1996         WIMStruct *w = wimfs_get_WIMStruct();
1997
1998         dentry = get_dentry(w, path);
1999         if (!dentry)
2000                 return -ENOENT;
2001
2002         if (!dentry_is_empty_directory(dentry))
2003                 return -ENOTEMPTY;
2004
2005         remove_dentry(dentry, w->lookup_table);
2006         return 0;
2007 }
2008
2009 #ifdef ENABLE_XATTR
2010 /* Write an alternate data stream through the XATTR interface */
2011 static int wimfs_setxattr(const char *path, const char *name,
2012                           const char *value, size_t size, int flags)
2013 {
2014         struct ads_entry *existing_ads_entry;
2015         struct ads_entry *new_ads_entry;
2016         struct lookup_table_entry *existing_lte;
2017         struct lookup_table_entry *lte;
2018         struct inode *inode;
2019         u8 value_hash[SHA1_HASH_SIZE];
2020         u16 ads_idx;
2021         struct wimfs_context *ctx = wimfs_get_context();
2022
2023         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
2024                 return -ENOTSUP;
2025
2026         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
2027                 return -ENOATTR;
2028         name += 5;
2029
2030         inode = wim_pathname_to_inode(ctx->wim, path);
2031         if (!inode)
2032                 return -ENOENT;
2033
2034         existing_ads_entry = inode_get_ads_entry(inode, name, &ads_idx);
2035         if (existing_ads_entry) {
2036                 if (flags & XATTR_CREATE)
2037                         return -EEXIST;
2038                 inode_remove_ads(inode, ads_idx, ctx->wim->lookup_table);
2039         } else {
2040                 if (flags & XATTR_REPLACE)
2041                         return -ENOATTR;
2042         }
2043         new_ads_entry = inode_add_ads(inode, name);
2044         if (!new_ads_entry)
2045                 return -ENOMEM;
2046
2047         sha1_buffer((const u8*)value, size, value_hash);
2048
2049         existing_lte = __lookup_resource(ctx->wim->lookup_table, value_hash);
2050
2051         if (existing_lte) {
2052                 lte = existing_lte;
2053                 lte->refcnt++;
2054         } else {
2055                 u8 *value_copy;
2056                 lte = new_lookup_table_entry();
2057                 if (!lte)
2058                         return -ENOMEM;
2059                 value_copy = MALLOC(size);
2060                 if (!value_copy) {
2061                         FREE(lte);
2062                         return -ENOMEM;
2063                 }
2064                 memcpy(value_copy, value, size);
2065                 lte->resource_location            = RESOURCE_IN_ATTACHED_BUFFER;
2066                 lte->attached_buffer              = value_copy;
2067                 lte->resource_entry.original_size = size;
2068                 lte->resource_entry.size          = size;
2069                 lte->resource_entry.flags         = 0;
2070                 copy_hash(lte->hash, value_hash);
2071                 lookup_table_insert(ctx->wim->lookup_table, lte);
2072         }
2073         new_ads_entry->lte = lte;
2074         return 0;
2075 }
2076 #endif
2077
2078 static int wimfs_symlink(const char *to, const char *from)
2079 {
2080         struct wimfs_context *ctx = wimfs_get_context();
2081         struct dentry *dentry;
2082         int ret;
2083
2084         ret = create_dentry(ctx, from, &dentry);
2085         if (ret == 0) {
2086                 dentry->d_inode->attributes = FILE_ATTRIBUTE_REPARSE_POINT;
2087                 dentry->d_inode->reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
2088                 if (inode_set_symlink(dentry->d_inode, to,
2089                                       ctx->wim->lookup_table, NULL))
2090                 {
2091                         unlink_dentry(dentry);
2092                         free_dentry(dentry);
2093                         ret = -ENOMEM;
2094                 }
2095         }
2096         return ret;
2097 }
2098
2099
2100 /* Reduce the size of a file */
2101 static int wimfs_truncate(const char *path, off_t size)
2102 {
2103         struct dentry *dentry;
2104         struct lookup_table_entry *lte;
2105         int ret;
2106         u16 stream_idx;
2107         u32 stream_id;
2108         struct inode *inode;
2109         struct wimfs_context *ctx = wimfs_get_context();
2110
2111         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
2112                               &dentry, &lte, &stream_idx);
2113
2114         if (ret != 0)
2115                 return ret;
2116
2117         if (lte == NULL && size == 0)
2118                 return 0;
2119
2120         inode = dentry->d_inode;
2121         if (stream_idx == 0)
2122                 stream_id = 0;
2123         else
2124                 stream_id = inode->ads_entries[stream_idx - 1].stream_id;
2125
2126         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
2127                 ret = truncate(lte->staging_file_name, size);
2128                 if (ret != 0)
2129                         ret = -errno;
2130         } else {
2131                 /* File in WIM.  Extract it to the staging directory, but only
2132                  * the first @size bytes of it. */
2133                 ret = extract_resource_to_staging_dir(inode, stream_id,
2134                                                       &lte, size, ctx);
2135         }
2136         return ret;
2137 }
2138
2139 /* Unlink a non-directory or alternate data stream */
2140 static int wimfs_unlink(const char *path)
2141 {
2142         struct dentry *dentry;
2143         struct lookup_table_entry *lte;
2144         int ret;
2145         u16 stream_idx;
2146         struct wimfs_context *ctx = wimfs_get_context();
2147
2148         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
2149                               &dentry, &lte, &stream_idx);
2150
2151         if (ret != 0)
2152                 return ret;
2153
2154         if (stream_idx == 0)
2155                 remove_dentry(dentry, ctx->wim->lookup_table);
2156         else
2157                 inode_remove_ads(dentry->d_inode, stream_idx - 1,
2158                                  ctx->wim->lookup_table);
2159         return 0;
2160 }
2161
2162 #ifdef HAVE_UTIMENSAT
2163 /*
2164  * Change the timestamp on a file dentry.
2165  *
2166  * Note that alternate data streams do not have their own timestamps.
2167  */
2168 static int wimfs_utimens(const char *path, const struct timespec tv[2])
2169 {
2170         struct dentry *dentry;
2171         struct inode *inode;
2172         WIMStruct *w = wimfs_get_WIMStruct();
2173
2174         dentry = get_dentry(w, path);
2175         if (!dentry)
2176                 return -ENOENT;
2177         inode = dentry->d_inode;
2178
2179         if (tv[0].tv_nsec != UTIME_OMIT) {
2180                 if (tv[0].tv_nsec == UTIME_NOW)
2181                         inode->last_access_time = get_wim_timestamp();
2182                 else
2183                         inode->last_access_time = timespec_to_wim_timestamp(&tv[0]);
2184         }
2185         if (tv[1].tv_nsec != UTIME_OMIT) {
2186                 if (tv[1].tv_nsec == UTIME_NOW)
2187                         inode->last_write_time = get_wim_timestamp();
2188                 else
2189                         inode->last_write_time = timespec_to_wim_timestamp(&tv[1]);
2190         }
2191         return 0;
2192 }
2193 #else
2194 static int wimfs_utime(const char *path, struct utimbuf *times)
2195 {
2196         struct dentry *dentry;
2197         struct inode *inode;
2198         WIMStruct *w = wimfs_get_WIMStruct();
2199
2200         dentry = get_dentry(w, path);
2201         if (!dentry)
2202                 return -ENOENT;
2203         inode = dentry->d_inode;
2204
2205         inode->last_write_time = unix_timestamp_to_wim(times->modtime);
2206         inode->last_access_time = unix_timestamp_to_wim(times->actime);
2207         return 0;
2208 }
2209 #endif
2210
2211 /* Writes to a file in the WIM filesystem.
2212  * It may be an alternate data stream, but here we don't even notice because we
2213  * just get a lookup table entry. */
2214 static int wimfs_write(const char *path, const char *buf, size_t size,
2215                        off_t offset, struct fuse_file_info *fi)
2216 {
2217         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
2218         int ret;
2219         u64 now;
2220
2221         if (!fd)
2222                 return -EBADF;
2223
2224         wimlib_assert(fd->f_lte);
2225         wimlib_assert(fd->f_lte->staging_file_name);
2226         wimlib_assert(fd->staging_fd != -1);
2227         wimlib_assert(fd->f_inode);
2228
2229         /* Seek to the requested position */
2230         if (lseek(fd->staging_fd, offset, SEEK_SET) == -1)
2231                 return -errno;
2232
2233         /* Write the data. */
2234         ret = write(fd->staging_fd, buf, size);
2235         if (ret == -1)
2236                 return -errno;
2237
2238         now = get_wim_timestamp();
2239         fd->f_inode->last_write_time = now;
2240         fd->f_inode->last_access_time = now;
2241         return ret;
2242 }
2243
2244 static struct fuse_operations wimfs_operations = {
2245         .access      = wimfs_access,
2246         .chmod       = wimfs_chmod,
2247         .destroy     = wimfs_destroy,
2248 #if 0
2249         .fallocate   = wimfs_fallocate,
2250 #endif
2251         .fgetattr    = wimfs_fgetattr,
2252         .ftruncate   = wimfs_ftruncate,
2253         .getattr     = wimfs_getattr,
2254 #ifdef ENABLE_XATTR
2255         .getxattr    = wimfs_getxattr,
2256 #endif
2257         .link        = wimfs_link,
2258 #ifdef ENABLE_XATTR
2259         .listxattr   = wimfs_listxattr,
2260 #endif
2261         .mkdir       = wimfs_mkdir,
2262         .mknod       = wimfs_mknod,
2263         .open        = wimfs_open,
2264         .opendir     = wimfs_opendir,
2265         .read        = wimfs_read,
2266         .readdir     = wimfs_readdir,
2267         .readlink    = wimfs_readlink,
2268         .release     = wimfs_release,
2269         .releasedir  = wimfs_releasedir,
2270 #ifdef ENABLE_XATTR
2271         .removexattr = wimfs_removexattr,
2272 #endif
2273         .rename      = wimfs_rename,
2274         .rmdir       = wimfs_rmdir,
2275 #ifdef ENABLE_XATTR
2276         .setxattr    = wimfs_setxattr,
2277 #endif
2278         .symlink     = wimfs_symlink,
2279         .truncate    = wimfs_truncate,
2280         .unlink      = wimfs_unlink,
2281 #ifdef HAVE_UTIMENSAT
2282         .utimens     = wimfs_utimens,
2283 #else
2284         .utime       = wimfs_utime,
2285 #endif
2286         .write       = wimfs_write,
2287
2288 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
2289         .flag_nullpath_ok = 1,
2290 #endif
2291 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 9)
2292         .flag_nopath = 1,
2293         .flag_utime_omit_ok = 1,
2294 #endif
2295 };
2296
2297
2298 /* Mounts an image from a WIM file. */
2299 WIMLIBAPI int wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
2300                                  int mount_flags, WIMStruct **additional_swms,
2301                                  unsigned num_additional_swms,
2302                                  const char *staging_dir)
2303 {
2304         int argc = 0;
2305         char *argv[16];
2306         int ret;
2307         char *dir_copy;
2308         struct lookup_table *joined_tab, *wim_tab_save;
2309         struct image_metadata *imd;
2310         struct wimfs_context ctx;
2311         struct hlist_node *cur_node;
2312         struct inode *inode;
2313
2314         DEBUG("Mount: wim = %p, image = %d, dir = %s, flags = %d, ",
2315               wim, image, dir, mount_flags);
2316
2317         if (!wim || !dir)
2318                 return WIMLIB_ERR_INVALID_PARAM;
2319
2320         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
2321         if (ret != 0)
2322                 return ret;
2323
2324         if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) && (wim->hdr.total_parts != 1)) {
2325                 ERROR("Cannot mount a split WIM read-write");
2326                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
2327         }
2328
2329         if (num_additional_swms) {
2330                 ret = new_joined_lookup_table(wim, additional_swms,
2331                                               num_additional_swms,
2332                                               &joined_tab);
2333                 if (ret != 0)
2334                         return ret;
2335                 wim_tab_save = wim->lookup_table;
2336                 wim->lookup_table = joined_tab;
2337         }
2338
2339         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2340                 ret = wim_run_full_verifications(wim);
2341                 if (ret != 0)
2342                         goto out;
2343         }
2344
2345         ret = select_wim_image(wim, image);
2346         if (ret != 0)
2347                 goto out;
2348
2349         DEBUG("Selected image %d", image);
2350
2351         imd = wim_get_current_image_metadata(wim);
2352
2353         if (imd->root_dentry->refcnt != 1) {
2354                 ERROR("Cannot mount image that was just exported with "
2355                       "wimlib_export_image()");
2356                 ret = WIMLIB_ERR_INVALID_PARAM;
2357                 goto out;
2358         }
2359
2360         if (imd->modified) {
2361                 ERROR("Cannot mount image that was added "
2362                       "with wimlib_add_image()");
2363                 ret = WIMLIB_ERR_INVALID_PARAM;
2364                 goto out;
2365         }
2366
2367         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2368                 ret = lock_wim(wim, wim->fp);
2369                 if (ret != 0)
2370                         goto out;
2371         }
2372
2373         if (!(mount_flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
2374                        WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
2375                        WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)))
2376                 mount_flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
2377
2378
2379         DEBUG("Initializing struct wimfs_context");
2380         init_wimfs_context(&ctx);
2381         ctx.wim = wim;
2382         ctx.mount_flags = mount_flags;
2383         ctx.image_inode_list = &imd->inode_list;
2384
2385         if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
2386                 ctx.default_lookup_flags = LOOKUP_FLAG_ADS_OK;
2387
2388         DEBUG("Unlinking message queues in case they already exist");
2389         ret = set_message_queue_names(&ctx, dir);
2390         if (ret != 0)
2391                 goto out_unlock;
2392         unlink_message_queues(&ctx);
2393
2394         DEBUG("Preparing arguments to fuse_main()");
2395
2396         dir_copy = STRDUP(dir);
2397         if (!dir_copy)
2398                 goto out_free_message_queue_names;
2399
2400         argv[argc++] = "imagex";
2401         argv[argc++] = dir_copy;
2402
2403         /* disable multi-threaded operation for read-write mounts */
2404         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)
2405                 argv[argc++] = "-s";
2406
2407         if (mount_flags & WIMLIB_MOUNT_FLAG_DEBUG)
2408                 argv[argc++] = "-d";
2409
2410         /*
2411          * We provide the use_ino option because we are going to assign inode
2412          * numbers oursides.  The inodes will be given unique numbers in the
2413          * assign_inode_numbers() function, and the static variable @next_ino is
2414          * set to the next available inode number.
2415          */
2416         char optstring[256] =
2417                 "use_ino"
2418                 ",subtype=wimfs"
2419                 ",attr_timeout=0"
2420 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
2421                 ",hard_remove"
2422 #endif
2423                 ;
2424         argv[argc++] = "-o";
2425         argv[argc++] = optstring;
2426         if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)) {
2427                 /* Read-write mount.  Make the staging directory */
2428                 ret = make_staging_dir(&ctx, staging_dir);
2429                 if (ret != 0)
2430                         goto out_free_dir_copy;
2431         } else {
2432                 /* Read-only mount */
2433                 strcat(optstring, ",ro");
2434         }
2435         argv[argc] = NULL;
2436
2437 #ifdef ENABLE_DEBUG
2438         {
2439                 int i;
2440                 DEBUG("FUSE command line (argc = %d): ", argc);
2441                 for (i = 0; i < argc; i++) {
2442                         fputs(argv[i], stdout);
2443                         putchar(' ');
2444                 }
2445                 putchar('\n');
2446                 fflush(stdout);
2447         }
2448 #endif
2449
2450         /* Mark dentry tree as modified if read-write mount. */
2451         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2452                 imd->modified = 1;
2453                 imd->has_been_mounted_rw = 1;
2454         }
2455
2456         /* Resolve the lookup table entries for every inode in the image, and
2457          * assign inode numbers */
2458         DEBUG("Resolving lookup table entries and assigning inode numbers");
2459
2460         ctx.next_ino = 1;
2461         hlist_for_each_entry(inode, cur_node, &imd->inode_list, hlist) {
2462                 inode_resolve_ltes(inode, wim->lookup_table);
2463                 inode->ino = ctx.next_ino++;
2464         }
2465         /*ctx.next_ino = assign_inode_numbers(&imd->inode_list);*/
2466         DEBUG("(next_ino = %"PRIu64")", ctx.next_ino);
2467
2468         DEBUG("Calling fuse_main()");
2469
2470         ret = fuse_main(argc, argv, &wimfs_operations, &ctx);
2471
2472         DEBUG("Returned from fuse_main() (ret = %d)", ret);
2473         if (ret)
2474                 ret = WIMLIB_ERR_FUSE;
2475 out_free_dir_copy:
2476         FREE(dir_copy);
2477 out_unlock:
2478         wim->wim_locked = 0;
2479 out_free_message_queue_names:
2480         free_message_queue_names(&ctx);
2481 out:
2482         if (num_additional_swms) {
2483                 free_lookup_table(wim->lookup_table);
2484                 wim->lookup_table = wim_tab_save;
2485         }
2486         return ret;
2487 }
2488
2489 /*
2490  * Unmounts the WIM file that was previously mounted on @dir by using
2491  * wimlib_mount_image().
2492  */
2493 WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
2494                                    wimlib_progress_func_t progress_func)
2495 {
2496         int ret;
2497         struct wimfs_context wimfs_ctx;
2498
2499         init_wimfs_context(&wimfs_ctx);
2500
2501         ret = set_message_queue_names(&wimfs_ctx, dir);
2502         if (ret != 0)
2503                 goto out;
2504
2505         ret = open_message_queues(&wimfs_ctx, false);
2506         if (ret != 0)
2507                 goto out_free_message_queue_names;
2508
2509         ret = send_unmount_request_msg(wimfs_ctx.unmount_to_daemon_mq,
2510                                        unmount_flags,
2511                                        progress_func != NULL);
2512         if (ret != 0)
2513                 goto out_close_message_queues;
2514
2515         ret = execute_fusermount(dir);
2516         if (ret != 0)
2517                 goto out_close_message_queues;
2518
2519         struct msg_handler_context handler_ctx = {
2520                 .timeout_seconds = 5,
2521                 .unmount = {
2522                         .daemon_pid = 0,
2523                         .progress_func = progress_func,
2524                 },
2525         };
2526
2527         ret = message_loop(wimfs_ctx.daemon_to_unmount_mq,
2528                            &unmount_msg_handler_callbacks,
2529                            &handler_ctx);
2530         if (ret == 0)
2531                 ret = handler_ctx.unmount.status;
2532 out_close_message_queues:
2533         close_message_queues(&wimfs_ctx);
2534 out_free_message_queue_names:
2535         free_message_queue_names(&wimfs_ctx);
2536 out:
2537         return ret;
2538 }
2539
2540 #else /* WITH_FUSE */
2541
2542
2543 static inline int mount_unsupported_error()
2544 {
2545         ERROR("wimlib was compiled with --without-fuse, which disables support "
2546               "for mounting WIMs.");
2547         return WIMLIB_ERR_UNSUPPORTED;
2548 }
2549
2550 WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
2551                                    wimlib_progress_func_t progress_func)
2552 {
2553         return mount_unsupported_error();
2554 }
2555
2556 WIMLIBAPI int wimlib_mount_image(WIMStruct *wim_p, int image, const char *dir,
2557                                  int mount_flags, WIMStruct **additional_swms,
2558                                  unsigned num_additional_swms,
2559                                  const char *staging_dir)
2560 {
2561         return mount_unsupported_error();
2562 }
2563
2564 #endif /* WITH_FUSE */