Ugly hack
[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 -errno;
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_hdr {
1020         int timeout_seconds;
1021 };
1022
1023 struct unmount_msg_handler_context {
1024         struct msg_handler_context_hdr hdr;
1025         pid_t daemon_pid;
1026         int mount_flags;
1027         int status;
1028         wimlib_progress_func_t progress_func;
1029 };
1030
1031 struct daemon_msg_handler_context {
1032         struct msg_handler_context_hdr hdr;
1033         struct wimfs_context *wimfs_ctx;
1034 };
1035
1036 static int send_unmount_request_msg(mqd_t mq, int unmount_flags,
1037                                     u8 want_progress_messages)
1038 {
1039         DEBUG("Sending unmount request msg");
1040         struct msg_unmount_request msg = {
1041                 .hdr = {
1042                         .min_version = WIMLIB_MAKEVERSION(1, 2, 1),
1043                         .cur_version = WIMLIB_VERSION_CODE,
1044                         .msg_type    = MSG_TYPE_UNMOUNT_REQUEST,
1045                         .msg_size    = sizeof(msg),
1046                 },
1047                 .unmount_flags = unmount_flags,
1048                 .want_progress_messages = want_progress_messages,
1049         };
1050
1051         if (mq_send(mq, (void*)&msg, sizeof(msg), 1)) {
1052                 ERROR_WITH_ERRNO("Failed to communicate with filesystem daemon");
1053                 return WIMLIB_ERR_MQUEUE;
1054         }
1055         return 0;
1056 }
1057
1058 static int send_daemon_info_msg(mqd_t mq, pid_t pid, int mount_flags)
1059 {
1060         DEBUG("Sending daemon info msg (pid = %d, mount_flags=%x)",
1061               pid, mount_flags);
1062
1063         struct msg_daemon_info msg = {
1064                 .hdr = {
1065                         .min_version = WIMLIB_MAKEVERSION(1, 2, 1),
1066                         .cur_version = WIMLIB_VERSION_CODE,
1067                         .msg_type = MSG_TYPE_DAEMON_INFO,
1068                         .msg_size = sizeof(msg),
1069                 },
1070                 .daemon_pid = pid,
1071                 .mount_flags = mount_flags,
1072         };
1073         if (mq_send(mq, (void*)&msg, sizeof(msg), 1)) {
1074                 ERROR_WITH_ERRNO("Failed to send daemon info to unmount process");
1075                 return WIMLIB_ERR_MQUEUE;
1076         }
1077         return 0;
1078 }
1079
1080 static void send_unmount_finished_msg(mqd_t mq, int status)
1081 {
1082         DEBUG("Sending unmount finished msg");
1083         struct msg_unmount_finished msg = {
1084                 .hdr = {
1085                         .min_version = WIMLIB_MAKEVERSION(1, 2, 1),
1086                         .cur_version = WIMLIB_VERSION_CODE,
1087                         .msg_type = MSG_TYPE_UNMOUNT_FINISHED,
1088                         .msg_size = sizeof(msg),
1089                 },
1090                 .status = status,
1091         };
1092         if (mq_send(mq, (void*)&msg, sizeof(msg), 1))
1093                 ERROR_WITH_ERRNO("Failed to send status to unmount process");
1094 }
1095
1096 static int unmount_progress_func(enum wimlib_progress_msg msg,
1097                                  const union wimlib_progress_info *info)
1098 {
1099         if (msg == WIMLIB_PROGRESS_MSG_WRITE_STREAMS) {
1100                 struct msg_write_streams_progress msg = {
1101                         .hdr = {
1102                                 .min_version = WIMLIB_MAKEVERSION(1, 2, 1),
1103                                 .cur_version = WIMLIB_VERSION_CODE,
1104                                 .msg_type = MSG_TYPE_WRITE_STREAMS_PROGRESS,
1105                                 .msg_size = sizeof(msg),
1106                         },
1107                         .info = *info,
1108                 };
1109                 if (mq_send(wimfs_get_context()->daemon_to_unmount_mq,
1110                             (void*)&msg, sizeof(msg), 1))
1111                 {
1112                         ERROR_WITH_ERRNO("Failed to send progress information "
1113                                          "to unmount process");
1114                 }
1115         }
1116         return 0;
1117 }
1118
1119 static int msg_unmount_request_handler(const void *_msg, void *_handler_ctx)
1120 {
1121         const struct msg_unmount_request *msg = _msg;
1122         struct daemon_msg_handler_context *handler_ctx = _handler_ctx;
1123         struct wimfs_context *wimfs_ctx;
1124         int status = 0;
1125         int ret;
1126         int unmount_flags;
1127         wimlib_progress_func_t progress_func;
1128
1129         DEBUG("Handling unmount request msg");
1130
1131         wimfs_ctx = handler_ctx->wimfs_ctx;
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, void *_handler_ctx)
1181 {
1182         const struct msg_daemon_info *msg = _msg;
1183         struct unmount_msg_handler_context *handler_ctx = _handler_ctx;
1184
1185         DEBUG("Handling daemon info msg");
1186         if (msg->hdr.msg_size < sizeof(*msg))
1187                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1188         handler_ctx->daemon_pid = msg->daemon_pid;
1189         handler_ctx->mount_flags = msg->mount_flags;
1190         handler_ctx->hdr.timeout_seconds = 1;
1191         DEBUG("pid of daemon is %d; mount flags were %#x",
1192               handler_ctx->daemon_pid,
1193               handler_ctx->mount_flags);
1194         return 0;
1195 }
1196
1197 static int msg_write_streams_progress_handler(const void *_msg,
1198                                               void *_handler_ctx)
1199 {
1200         const struct msg_write_streams_progress *msg = _msg;
1201         struct unmount_msg_handler_context *handler_ctx = _handler_ctx;
1202
1203         if (msg->hdr.msg_size < sizeof(*msg))
1204                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1205         if (handler_ctx->progress_func) {
1206                 handler_ctx->progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS,
1207                                            &msg->info);
1208         }
1209         return 0;
1210 }
1211
1212 static int msg_unmount_finished_handler(const void *_msg, void *_handler_ctx)
1213 {
1214         const struct msg_unmount_finished *msg = _msg;
1215         struct unmount_msg_handler_context *handler_ctx = _handler_ctx;
1216
1217         DEBUG("Handling unmount finished message");
1218         if (msg->hdr.msg_size < sizeof(*msg))
1219                 return WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1220         handler_ctx->status = msg->status;
1221         DEBUG("status is %d", handler_ctx->status);
1222         return MSG_BREAK_LOOP;
1223 }
1224
1225 static int unmount_timed_out_cb(void *_handler_ctx)
1226 {
1227         struct unmount_msg_handler_context *handler_ctx = _handler_ctx;
1228
1229         if (handler_ctx->daemon_pid == 0) {
1230                 goto out_crashed;
1231         } else {
1232                 kill(handler_ctx->daemon_pid, 0);
1233                 if (errno == ESRCH) {
1234                         goto out_crashed;
1235                 } else {
1236                         DEBUG("Filesystem daemon is still alive... "
1237                               "Waiting another %d seconds\n",
1238                               handler_ctx->hdr.timeout_seconds);
1239                         return 0;
1240                 }
1241         }
1242 out_crashed:
1243         ERROR("The filesystem daemon has crashed!  Changes to the "
1244               "WIM may not have been commited.");
1245         return WIMLIB_ERR_FILESYSTEM_DAEMON_CRASHED;
1246 }
1247
1248 static int daemon_timed_out_cb(void *_handler_ctx)
1249 {
1250         ERROR("Timed out waiting for unmount request! "
1251               "Changes to the mounted WIM will not be committed.");
1252         return WIMLIB_ERR_TIMEOUT;
1253 }
1254
1255 typedef int (*msg_handler_t)(const void *_msg, void *_handler_ctx);
1256
1257 struct msg_handler_callbacks {
1258         int (*timed_out)(void * _handler_ctx);
1259         msg_handler_t msg_handlers[MSG_TYPE_MAX];
1260 };
1261
1262 static const struct msg_handler_callbacks unmount_msg_handler_callbacks = {
1263         .timed_out = unmount_timed_out_cb,
1264         .msg_handlers = {
1265                 [MSG_TYPE_DAEMON_INFO] = msg_daemon_info_handler,
1266                 [MSG_TYPE_WRITE_STREAMS_PROGRESS] = msg_write_streams_progress_handler,
1267                 [MSG_TYPE_UNMOUNT_FINISHED] = msg_unmount_finished_handler,
1268         },
1269 };
1270
1271 static const struct msg_handler_callbacks daemon_msg_handler_callbacks = {
1272         .timed_out = daemon_timed_out_cb,
1273         .msg_handlers = {
1274                 [MSG_TYPE_UNMOUNT_REQUEST] = msg_unmount_request_handler,
1275         },
1276 };
1277
1278 static int receive_message(mqd_t mq,
1279                            struct msg_handler_context_hdr *handler_ctx,
1280                            const msg_handler_t msg_handlers[],
1281                            long mailbox_size, void *mailbox)
1282 {
1283         struct timeval now;
1284         struct timespec timeout;
1285         ssize_t bytes_received;
1286         struct unmount_msg_hdr *hdr;
1287         int ret;
1288
1289         gettimeofday(&now, NULL);
1290         timeout.tv_sec = now.tv_sec + handler_ctx->timeout_seconds;
1291         timeout.tv_nsec = now.tv_usec * 1000;
1292
1293         bytes_received = mq_timedreceive(mq, mailbox,
1294                                          mailbox_size, NULL, &timeout);
1295         hdr = mailbox;
1296         if (bytes_received == -1) {
1297                 if (errno == ETIMEDOUT) {
1298                         ret = WIMLIB_ERR_TIMEOUT;
1299                 } else {
1300                         ERROR_WITH_ERRNO("mq_timedreceive()");
1301                         ret = WIMLIB_ERR_MQUEUE;
1302                 }
1303         } else if (bytes_received < sizeof(*hdr) ||
1304                    bytes_received != hdr->msg_size) {
1305                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1306         } else if (WIMLIB_VERSION_CODE < hdr->min_version) {
1307                 /*ERROR("Cannot understand the received message. "*/
1308                       /*"Please upgrade wimlib to at least v%d.%d.%d",*/
1309                       /*WIMLIB_GET_MAJOR_VERSION(hdr->min_version),*/
1310                       /*WIMLIB_GET_MINOR_VERSION(hdr->min_version),*/
1311                       /*WIMLIB_GET_PATCH_VERSION(hdr->min_version));*/
1312                 ret = MSG_VERSION_TOO_HIGH;
1313         } else if (hdr->msg_type >= MSG_TYPE_MAX) {
1314                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1315         } else if (msg_handlers[hdr->msg_type] == NULL) {
1316                 ret = WIMLIB_ERR_INVALID_UNMOUNT_MESSAGE;
1317         } else {
1318                 ret = msg_handlers[hdr->msg_type](mailbox, handler_ctx);
1319         }
1320         return ret;
1321 }
1322
1323 static int message_loop(mqd_t mq,
1324                         const struct msg_handler_callbacks *callbacks,
1325                         struct msg_handler_context_hdr *handler_ctx)
1326 {
1327         static const size_t MAX_MSG_SIZE = 512;
1328         long msgsize;
1329         void *mailbox;
1330         int ret;
1331
1332         DEBUG("Entering message loop");
1333
1334         ret = get_mailbox(mq, MAX_MSG_SIZE, &msgsize, &mailbox);
1335         if (ret != 0)
1336                 return ret;
1337         while (1) {
1338                 ret = receive_message(mq, handler_ctx,
1339                                       callbacks->msg_handlers,
1340                                       msgsize, mailbox);
1341                 if (ret == 0 || ret == MSG_VERSION_TOO_HIGH) {
1342                         continue;
1343                 } else if (ret == MSG_BREAK_LOOP) {
1344                         ret = 0;
1345                         break;
1346                 } else if (ret == WIMLIB_ERR_TIMEOUT) {
1347                         if (callbacks->timed_out)
1348                                 ret = callbacks->timed_out(handler_ctx);
1349                         if (ret == 0)
1350                                 continue;
1351                         else
1352                                 break;
1353                 } else {
1354                         ERROR_WITH_ERRNO("Error communicating with "
1355                                          "filesystem daemon");
1356                         break;
1357                 }
1358         }
1359         FREE(mailbox);
1360         DEBUG("Exiting message loop");
1361         return ret;
1362 }
1363
1364 /* Execute `fusermount -u', which is installed setuid root, to unmount the WIM.
1365  *
1366  * FUSE does not yet implement synchronous unmounts.  This means that fusermount
1367  * -u will return before the filesystem daemon returns from wimfs_destroy().
1368  *  This is partly what we want, because we need to send a message from this
1369  *  process to the filesystem daemon telling whether --commit was specified or
1370  *  not.  However, after that, the unmount process must wait for the filesystem
1371  *  daemon to finish writing the WIM file.
1372  */
1373 static int execute_fusermount(const char *dir)
1374 {
1375         pid_t pid;
1376         int ret;
1377         int status;
1378
1379         pid = fork();
1380         if (pid == -1) {
1381                 ERROR_WITH_ERRNO("Failed to fork()");
1382                 return WIMLIB_ERR_FORK;
1383         }
1384         if (pid == 0) {
1385                 /* Child */
1386                 execlp("fusermount", "fusermount", "-u", dir, NULL);
1387                 ERROR_WITH_ERRNO("Failed to execute `fusermount'");
1388                 exit(WIMLIB_ERR_FUSERMOUNT);
1389         }
1390
1391         /* Parent */
1392         ret = waitpid(pid, &status, 0);
1393         if (ret == -1) {
1394                 ERROR_WITH_ERRNO("Failed to wait for fusermount process to "
1395                                  "terminate");
1396                 return WIMLIB_ERR_FUSERMOUNT;
1397         }
1398
1399         if (!WIFEXITED(status)) {
1400                 ERROR("'fusermount' did not terminate normally!");
1401                 return WIMLIB_ERR_FUSERMOUNT;
1402         }
1403
1404         status = WEXITSTATUS(status);
1405
1406         if (status == 0)
1407                 return 0;
1408
1409         if (status != WIMLIB_ERR_FUSERMOUNT)
1410                 return WIMLIB_ERR_FUSERMOUNT;
1411
1412         /* Try again, but with the `umount' program.  This is required on other
1413          * FUSE implementations such as FreeBSD's that do not have a
1414          * `fusermount' program. */
1415         ERROR("Falling back to 'umount'.  Note: you may need to be "
1416               "root for this to work");
1417         pid = fork();
1418         if (pid == -1) {
1419                 ERROR_WITH_ERRNO("Failed to fork()");
1420                 return WIMLIB_ERR_FORK;
1421         }
1422         if (pid == 0) {
1423                 /* Child */
1424                 execlp("umount", "umount", dir, NULL);
1425                 ERROR_WITH_ERRNO("Failed to execute `umount'");
1426                 exit(WIMLIB_ERR_FUSERMOUNT);
1427         }
1428
1429         /* Parent */
1430         ret = waitpid(pid, &status, 0);
1431         if (ret == -1) {
1432                 ERROR_WITH_ERRNO("Failed to wait for `umount' process to "
1433                                  "terminate");
1434                 return WIMLIB_ERR_FUSERMOUNT;
1435         }
1436         if (status != 0) {
1437                 ERROR("`umount' did not successfully complete");
1438                 return WIMLIB_ERR_FUSERMOUNT;
1439         }
1440         return 0;
1441 }
1442
1443 static int wimfs_access(const char *path, int mask)
1444 {
1445         /* Permissions not implemented */
1446         return 0;
1447 }
1448
1449 static int wimfs_chmod(const char *path, mode_t mask)
1450 {
1451         struct dentry *dentry;
1452         struct wimfs_context *ctx = wimfs_get_context();
1453         struct inode *inode;
1454         struct stat stbuf;
1455         int ret;
1456
1457         ret = lookup_resource(ctx->wim, path,
1458                               get_lookup_flags(ctx) | LOOKUP_FLAG_DIRECTORY_OK,
1459                               &dentry, NULL, NULL);
1460         if (ret != 0)
1461                 return ret;
1462         inode = dentry->d_inode;
1463         inode_to_stbuf(inode, NULL, &stbuf);
1464         if (mask == stbuf.st_mode)
1465                 return 0;
1466         else
1467                 return -EPERM;
1468 }
1469
1470 /* Called when the filesystem is unmounted. */
1471 static void wimfs_destroy(void *p)
1472 {
1473         struct wimfs_context *wimfs_ctx = wimfs_get_context();
1474         if (open_message_queues(wimfs_ctx, true) == 0) {
1475                 struct daemon_msg_handler_context handler_ctx = {
1476                         .hdr = {
1477                                 .timeout_seconds = 5,
1478                         },
1479                         .wimfs_ctx = wimfs_ctx,
1480                 };
1481                 message_loop(wimfs_ctx->unmount_to_daemon_mq,
1482                              &daemon_msg_handler_callbacks,
1483                              &handler_ctx.hdr);
1484                 close_message_queues(wimfs_ctx);
1485         }
1486 }
1487
1488 #if 0
1489 static int wimfs_fallocate(const char *path, int mode,
1490                            off_t offset, off_t len, struct fuse_file_info *fi)
1491 {
1492         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1493         wimlib_assert(fd->staging_fd != -1);
1494         return fallocate(fd->staging_fd, mode, offset, len);
1495 }
1496
1497 #endif
1498
1499 static int wimfs_fgetattr(const char *path, struct stat *stbuf,
1500                           struct fuse_file_info *fi)
1501 {
1502         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1503         return inode_to_stbuf(fd->f_inode, fd->f_lte, stbuf);
1504 }
1505
1506 static int wimfs_ftruncate(const char *path, off_t size,
1507                            struct fuse_file_info *fi)
1508 {
1509         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1510         int ret = ftruncate(fd->staging_fd, size);
1511         if (ret != 0)
1512                 return -errno;
1513         if (fd->f_lte && size < fd->f_lte->resource_entry.original_size)
1514                 fd->f_lte->resource_entry.original_size = size;
1515         return 0;
1516 }
1517
1518 /*
1519  * Fills in a `struct stat' that corresponds to a file or directory in the WIM.
1520  */
1521 static int wimfs_getattr(const char *path, struct stat *stbuf)
1522 {
1523         struct dentry *dentry;
1524         struct lookup_table_entry *lte;
1525         int ret;
1526         struct wimfs_context *ctx = wimfs_get_context();
1527
1528         ret = lookup_resource(ctx->wim, path,
1529                               get_lookup_flags(ctx) | LOOKUP_FLAG_DIRECTORY_OK,
1530                               &dentry, &lte, NULL);
1531         if (ret != 0)
1532                 return ret;
1533         return inode_to_stbuf(dentry->d_inode, lte, stbuf);
1534 }
1535
1536 #ifdef ENABLE_XATTR
1537 /* Read an alternate data stream through the XATTR interface, or get its size */
1538 static int wimfs_getxattr(const char *path, const char *name, char *value,
1539                           size_t size)
1540 {
1541         int ret;
1542         struct inode *inode;
1543         struct ads_entry *ads_entry;
1544         size_t res_size;
1545         struct lookup_table_entry *lte;
1546         struct wimfs_context *ctx = wimfs_get_context();
1547
1548         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1549                 return -ENOTSUP;
1550
1551         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
1552                 return -ENOATTR;
1553         name += 5;
1554
1555         inode = wim_pathname_to_inode(ctx->wim, path);
1556         if (!inode)
1557                 return -ENOENT;
1558
1559         ads_entry = inode_get_ads_entry(inode, name, NULL);
1560         if (!ads_entry)
1561                 return -ENOATTR;
1562
1563         lte = ads_entry->lte;
1564         res_size = wim_resource_size(lte);
1565
1566         if (size == 0)
1567                 return res_size;
1568
1569         if (res_size > size)
1570                 return -ERANGE;
1571
1572         ret = read_full_wim_resource(lte, (u8*)value,
1573                                      WIMLIB_RESOURCE_FLAG_MULTITHREADED);
1574         if (ret != 0)
1575                 return -EIO;
1576
1577         return res_size;
1578 }
1579 #endif
1580
1581 /* Create a hard link */
1582 static int wimfs_link(const char *to, const char *from)
1583 {
1584         struct dentry *from_dentry, *from_dentry_parent;
1585         const char *link_name;
1586         struct inode *inode;
1587         struct lookup_table_entry *lte;
1588         WIMStruct *w = wimfs_get_WIMStruct();
1589         u16 i;
1590
1591         inode = wim_pathname_to_inode(w, to);
1592         if (!inode)
1593                 return -ENOENT;
1594
1595         if (inode->attributes & FILE_ATTRIBUTE_REPARSE_POINT)
1596                 return -EEXIST;
1597
1598         if (inode->attributes & FILE_ATTRIBUTE_DIRECTORY)
1599                 return -EPERM;
1600
1601         from_dentry_parent = get_parent_dentry(w, from);
1602         if (!from_dentry_parent)
1603                 return -ENOENT;
1604         if (!dentry_is_directory(from_dentry_parent))
1605                 return -ENOTDIR;
1606
1607         link_name = path_basename(from);
1608         if (get_dentry_child_with_name(from_dentry_parent, link_name))
1609                 return -EEXIST;
1610         from_dentry = new_dentry(link_name);
1611         if (!from_dentry)
1612                 return -errno;
1613
1614         inode_add_dentry(from_dentry, inode);
1615         from_dentry->d_inode = inode;
1616         inode->link_count++;
1617
1618         for (i = 0; i <= inode->num_ads; i++) {
1619                 lte = inode_stream_lte_resolved(inode, i);
1620                 if (lte)
1621                         lte->refcnt++;
1622         }
1623         dentry_add_child(from_dentry_parent, from_dentry);
1624         return 0;
1625 }
1626
1627 #ifdef ENABLE_XATTR
1628 static int wimfs_listxattr(const char *path, char *list, size_t size)
1629 {
1630         size_t needed_size;
1631         struct inode *inode;
1632         struct wimfs_context *ctx = wimfs_get_context();
1633         u16 i;
1634         char *p;
1635
1636         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1637                 return -ENOTSUP;
1638
1639         /* List alternate data streams, or get the list size */
1640
1641         inode = wim_pathname_to_inode(ctx->wim, path);
1642         if (!inode)
1643                 return -ENOENT;
1644
1645         if (size == 0) {
1646                 needed_size = 0;
1647                 for (i = 0; i < inode->num_ads; i++)
1648                         needed_size += inode->ads_entries[i].stream_name_utf8_len + 6;
1649                 return needed_size;
1650         } else {
1651                 p = list;
1652                 for (i = 0; i < inode->num_ads; i++) {
1653                         needed_size = inode->ads_entries[i].stream_name_utf8_len + 6;
1654                         if (needed_size > size)
1655                                 return -ERANGE;
1656                         p += sprintf(p, "user.%s",
1657                                      inode->ads_entries[i].stream_name_utf8) + 1;
1658                         size -= needed_size;
1659                 }
1660                 return p - list;
1661         }
1662 }
1663 #endif
1664
1665
1666 /* Create a directory in the WIM.
1667  * @mode is currently ignored.  */
1668 static int wimfs_mkdir(const char *path, mode_t mode)
1669 {
1670         struct dentry *dentry;
1671         int ret;
1672
1673         ret = create_dentry(wimfs_get_context(), path, &dentry);
1674         if (ret == 0)
1675                 dentry->d_inode->attributes = FILE_ATTRIBUTE_DIRECTORY;
1676         return ret;
1677 }
1678
1679 /* Create a regular file in the WIM.
1680  * @mode is currently ignored.  */
1681 static int wimfs_mknod(const char *path, mode_t mode, dev_t rdev)
1682 {
1683         const char *stream_name;
1684         struct wimfs_context *ctx = wimfs_get_context();
1685         if ((ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
1686              && (stream_name = path_stream_name(path))) {
1687                 /* Make an alternate data stream */
1688                 struct ads_entry *new_entry;
1689                 struct inode *inode;
1690
1691                 char *p = (char*)stream_name - 1;
1692                 wimlib_assert(*p == ':');
1693                 *p = '\0';
1694
1695                 inode = wim_pathname_to_inode(ctx->wim, path);
1696                 if (!inode)
1697                         return -ENOENT;
1698                 if (inode->attributes &
1699                     (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY))
1700                         return -ENOENT;
1701                 if (inode_get_ads_entry(inode, stream_name, NULL))
1702                         return -EEXIST;
1703                 new_entry = inode_add_ads(inode, stream_name);
1704                 if (!new_entry)
1705                         return -ENOMEM;
1706                 return 0;
1707         } else {
1708                 struct dentry *dentry;
1709                 int ret;
1710
1711                 /* Make a normal file (not an alternate data stream) */
1712                 ret = create_dentry(ctx, path, &dentry);
1713                 if (ret == 0)
1714                         dentry->d_inode->attributes = FILE_ATTRIBUTE_NORMAL;
1715                 return ret;
1716         }
1717 }
1718
1719
1720 /* Open a file.  */
1721 static int wimfs_open(const char *path, struct fuse_file_info *fi)
1722 {
1723         struct dentry *dentry;
1724         struct lookup_table_entry *lte;
1725         int ret;
1726         struct wimlib_fd *fd;
1727         struct inode *inode;
1728         u16 stream_idx;
1729         u32 stream_id;
1730         struct wimfs_context *ctx = wimfs_get_context();
1731
1732         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
1733                               &dentry, &lte, &stream_idx);
1734         if (ret != 0)
1735                 return ret;
1736
1737         inode = dentry->d_inode;
1738
1739         if (stream_idx == 0)
1740                 stream_id = 0;
1741         else
1742                 stream_id = inode->ads_entries[stream_idx - 1].stream_id;
1743
1744         /* The file resource may be in the staging directory (read-write mounts
1745          * only) or in the WIM.  If it's in the staging directory, we need to
1746          * open a native file descriptor for the corresponding file.  Otherwise,
1747          * we can read the file resource directly from the WIM file if we are
1748          * opening it read-only, but we need to extract the resource to the
1749          * staging directory if we are opening it writable. */
1750
1751         if (flags_writable(fi->flags) &&
1752             (!lte || lte->resource_location != RESOURCE_IN_STAGING_FILE)) {
1753                 u64 size = (lte) ? wim_resource_size(lte) : 0;
1754                 ret = extract_resource_to_staging_dir(inode, stream_id,
1755                                                       &lte, size, ctx);
1756                 if (ret != 0)
1757                         return ret;
1758         }
1759
1760         ret = alloc_wimlib_fd(inode, stream_id, lte, &fd,
1761                               wimfs_ctx_readonly(ctx));
1762         if (ret != 0)
1763                 return ret;
1764
1765         if (lte && lte->resource_location == RESOURCE_IN_STAGING_FILE) {
1766                 fd->staging_fd = open(lte->staging_file_name, fi->flags);
1767                 if (fd->staging_fd == -1) {
1768                         int errno_save = errno;
1769                         close_wimlib_fd(fd);
1770                         return -errno_save;
1771                 }
1772         }
1773         fi->fh = (uintptr_t)fd;
1774         return 0;
1775 }
1776
1777 /* Opens a directory. */
1778 static int wimfs_opendir(const char *path, struct fuse_file_info *fi)
1779 {
1780         struct inode *inode;
1781         int ret;
1782         struct wimlib_fd *fd = NULL;
1783         struct wimfs_context *ctx = wimfs_get_context();
1784         WIMStruct *w = ctx->wim;
1785
1786         inode = wim_pathname_to_inode(w, path);
1787         if (!inode)
1788                 return -ENOENT;
1789         if (!inode_is_directory(inode))
1790                 return -ENOTDIR;
1791         ret = alloc_wimlib_fd(inode, 0, NULL, &fd, wimfs_ctx_readonly(ctx));
1792         fi->fh = (uintptr_t)fd;
1793         return ret;
1794 }
1795
1796
1797 /*
1798  * Read data from a file in the WIM or in the staging directory.
1799  */
1800 static int wimfs_read(const char *path, char *buf, size_t size,
1801                       off_t offset, struct fuse_file_info *fi)
1802 {
1803         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1804         ssize_t ret;
1805
1806         if (!fd)
1807                 return -EBADF;
1808
1809         if (!fd->f_lte) /* Empty stream with no lookup table entry */
1810                 return 0;
1811
1812         if (fd->f_lte->resource_location == RESOURCE_IN_STAGING_FILE) {
1813                 /* Read from staging file */
1814
1815                 wimlib_assert(fd->f_lte->staging_file_name);
1816                 wimlib_assert(fd->staging_fd != -1);
1817
1818                 DEBUG("Seek to offset %zu", offset);
1819
1820                 if (lseek(fd->staging_fd, offset, SEEK_SET) == -1)
1821                         return -errno;
1822                 ret = read(fd->staging_fd, buf, size);
1823                 if (ret == -1)
1824                         return -errno;
1825                 return ret;
1826         } else {
1827                 /* Read from WIM */
1828                 u64 res_size = wim_resource_size(fd->f_lte);
1829                 if (offset > res_size)
1830                         return -EOVERFLOW;
1831                 size = min(size, res_size - offset);
1832                 if (read_wim_resource(fd->f_lte, (u8*)buf,
1833                                       size, offset,
1834                                       WIMLIB_RESOURCE_FLAG_MULTITHREADED) != 0)
1835                         return -EIO;
1836                 return size;
1837         }
1838 }
1839
1840 struct fill_params {
1841         void *buf;
1842         fuse_fill_dir_t filler;
1843 };
1844
1845 static int dentry_fuse_fill(struct dentry *dentry, void *arg)
1846 {
1847         struct fill_params *fill_params = arg;
1848         return fill_params->filler(fill_params->buf, dentry->file_name_utf8,
1849                                    NULL, 0);
1850 }
1851
1852 /* Fills in the entries of the directory specified by @path using the
1853  * FUSE-provided function @filler.  */
1854 static int wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
1855                          off_t offset, struct fuse_file_info *fi)
1856 {
1857         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1858         struct inode *inode;
1859
1860         if (!fd)
1861                 return -EBADF;
1862
1863         inode = fd->f_inode;
1864
1865         struct fill_params fill_params = {
1866                 .buf = buf,
1867                 .filler = filler,
1868         };
1869
1870         filler(buf, ".", NULL, 0);
1871         filler(buf, "..", NULL, 0);
1872
1873         return for_dentry_in_rbtree(inode->children.rb_node,
1874                                     dentry_fuse_fill, &fill_params);
1875 }
1876
1877
1878 static int wimfs_readlink(const char *path, char *buf, size_t buf_len)
1879 {
1880         struct wimfs_context *ctx = wimfs_get_context();
1881         struct inode *inode = wim_pathname_to_inode(ctx->wim, path);
1882         int ret;
1883         if (!inode)
1884                 return -ENOENT;
1885         if (!inode_is_symlink(inode))
1886                 return -EINVAL;
1887
1888         ret = inode_readlink(inode, buf, buf_len, ctx->wim,
1889                              WIMLIB_RESOURCE_FLAG_MULTITHREADED);
1890         if (ret > 0)
1891                 ret = 0;
1892         return ret;
1893 }
1894
1895 /* Close a file. */
1896 static int wimfs_release(const char *path, struct fuse_file_info *fi)
1897 {
1898         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1899         return close_wimlib_fd(fd);
1900 }
1901
1902 /* Close a directory */
1903 static int wimfs_releasedir(const char *path, struct fuse_file_info *fi)
1904 {
1905         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
1906         return close_wimlib_fd(fd);
1907 }
1908
1909 #ifdef ENABLE_XATTR
1910 /* Remove an alternate data stream through the XATTR interface */
1911 static int wimfs_removexattr(const char *path, const char *name)
1912 {
1913         struct inode *inode;
1914         struct ads_entry *ads_entry;
1915         u16 ads_idx;
1916         struct wimfs_context *ctx = wimfs_get_context();
1917
1918         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1919                 return -ENOTSUP;
1920
1921         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
1922                 return -ENOATTR;
1923         name += 5;
1924
1925         inode = wim_pathname_to_inode(ctx->wim, path);
1926         if (!inode)
1927                 return -ENOENT;
1928
1929         ads_entry = inode_get_ads_entry(inode, name, &ads_idx);
1930         if (!ads_entry)
1931                 return -ENOATTR;
1932         inode_remove_ads(inode, ads_idx, ctx->wim->lookup_table);
1933         return 0;
1934 }
1935 #endif
1936
1937 /* Renames a file or directory.  See rename (3) */
1938 static int wimfs_rename(const char *from, const char *to)
1939 {
1940         struct dentry *src;
1941         struct dentry *dst;
1942         struct dentry *parent_of_dst;
1943         char *file_name_utf16 = NULL, *file_name_utf8 = NULL;
1944         u16 file_name_utf16_len, file_name_utf8_len;
1945         WIMStruct *w = wimfs_get_WIMStruct();
1946         int ret;
1947
1948         /* This rename() implementation currently only supports actual files
1949          * (not alternate data streams) */
1950
1951         src = get_dentry(w, from);
1952         if (!src)
1953                 return -ENOENT;
1954
1955         dst = get_dentry(w, to);
1956
1957         ret = get_names(&file_name_utf16, &file_name_utf8,
1958                         &file_name_utf16_len, &file_name_utf8_len,
1959                         path_basename(to));
1960         if (ret != 0)
1961                 return -ENOMEM;
1962
1963         if (dst) {
1964                 /* Destination file exists */
1965
1966                 if (src == dst) /* Same file */
1967                         return 0;
1968
1969                 if (!dentry_is_directory(src)) {
1970                         /* Cannot rename non-directory to directory. */
1971                         if (dentry_is_directory(dst))
1972                                 return -EISDIR;
1973                 } else {
1974                         /* Cannot rename directory to a non-directory or a non-empty
1975                          * directory */
1976                         if (!dentry_is_directory(dst))
1977                                 return -ENOTDIR;
1978                         if (inode_has_children(dst->d_inode))
1979                                 return -ENOTEMPTY;
1980                 }
1981                 parent_of_dst = dst->parent;
1982                 remove_dentry(dst, w->lookup_table);
1983         } else {
1984                 /* Destination does not exist */
1985                 parent_of_dst = get_parent_dentry(w, to);
1986                 if (!parent_of_dst)
1987                         return -ENOENT;
1988
1989                 if (!dentry_is_directory(parent_of_dst))
1990                         return -ENOTDIR;
1991         }
1992
1993         FREE(src->file_name);
1994         FREE(src->file_name_utf8);
1995         src->file_name          = file_name_utf16;
1996         src->file_name_utf8     = file_name_utf8;
1997         src->file_name_len      = file_name_utf16_len;
1998         src->file_name_utf8_len = file_name_utf8_len;
1999
2000         unlink_dentry(src);
2001         dentry_add_child(parent_of_dst, src);
2002         return 0;
2003 }
2004
2005 /* Remove a directory */
2006 static int wimfs_rmdir(const char *path)
2007 {
2008         struct dentry *dentry;
2009         WIMStruct *w = wimfs_get_WIMStruct();
2010
2011         dentry = get_dentry(w, path);
2012         if (!dentry)
2013                 return -ENOENT;
2014
2015         if (!dentry_is_empty_directory(dentry))
2016                 return -ENOTEMPTY;
2017
2018         remove_dentry(dentry, w->lookup_table);
2019         return 0;
2020 }
2021
2022 #ifdef ENABLE_XATTR
2023 /* Write an alternate data stream through the XATTR interface */
2024 static int wimfs_setxattr(const char *path, const char *name,
2025                           const char *value, size_t size, int flags)
2026 {
2027         struct ads_entry *existing_ads_entry;
2028         struct ads_entry *new_ads_entry;
2029         struct lookup_table_entry *existing_lte;
2030         struct lookup_table_entry *lte;
2031         struct inode *inode;
2032         u8 value_hash[SHA1_HASH_SIZE];
2033         u16 ads_idx;
2034         struct wimfs_context *ctx = wimfs_get_context();
2035
2036         if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
2037                 return -ENOTSUP;
2038
2039         if (strlen(name) < 5 || memcmp(name, "user.", 5) != 0)
2040                 return -ENOATTR;
2041         name += 5;
2042
2043         inode = wim_pathname_to_inode(ctx->wim, path);
2044         if (!inode)
2045                 return -ENOENT;
2046
2047         existing_ads_entry = inode_get_ads_entry(inode, name, &ads_idx);
2048         if (existing_ads_entry) {
2049                 if (flags & XATTR_CREATE)
2050                         return -EEXIST;
2051                 inode_remove_ads(inode, ads_idx, ctx->wim->lookup_table);
2052         } else {
2053                 if (flags & XATTR_REPLACE)
2054                         return -ENOATTR;
2055         }
2056         new_ads_entry = inode_add_ads(inode, name);
2057         if (!new_ads_entry)
2058                 return -ENOMEM;
2059
2060         sha1_buffer((const u8*)value, size, value_hash);
2061
2062         existing_lte = __lookup_resource(ctx->wim->lookup_table, value_hash);
2063
2064         if (existing_lte) {
2065                 lte = existing_lte;
2066                 lte->refcnt++;
2067         } else {
2068                 u8 *value_copy;
2069                 lte = new_lookup_table_entry();
2070                 if (!lte)
2071                         return -ENOMEM;
2072                 value_copy = MALLOC(size);
2073                 if (!value_copy) {
2074                         FREE(lte);
2075                         return -ENOMEM;
2076                 }
2077                 memcpy(value_copy, value, size);
2078                 lte->resource_location            = RESOURCE_IN_ATTACHED_BUFFER;
2079                 lte->attached_buffer              = value_copy;
2080                 lte->resource_entry.original_size = size;
2081                 lte->resource_entry.size          = size;
2082                 lte->resource_entry.flags         = 0;
2083                 copy_hash(lte->hash, value_hash);
2084                 lookup_table_insert(ctx->wim->lookup_table, lte);
2085         }
2086         new_ads_entry->lte = lte;
2087         return 0;
2088 }
2089 #endif
2090
2091 static int wimfs_symlink(const char *to, const char *from)
2092 {
2093         struct wimfs_context *ctx = wimfs_get_context();
2094         struct dentry *dentry;
2095         int ret;
2096
2097         ret = create_dentry(ctx, from, &dentry);
2098         if (ret == 0) {
2099                 dentry->d_inode->attributes = FILE_ATTRIBUTE_REPARSE_POINT;
2100                 dentry->d_inode->reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
2101                 if (inode_set_symlink(dentry->d_inode, to,
2102                                       ctx->wim->lookup_table, NULL))
2103                 {
2104                         unlink_dentry(dentry);
2105                         free_dentry(dentry);
2106                         ret = -ENOMEM;
2107                 }
2108         }
2109         return ret;
2110 }
2111
2112
2113 /* Reduce the size of a file */
2114 static int wimfs_truncate(const char *path, off_t size)
2115 {
2116         struct dentry *dentry;
2117         struct lookup_table_entry *lte;
2118         int ret;
2119         u16 stream_idx;
2120         u32 stream_id;
2121         struct inode *inode;
2122         struct wimfs_context *ctx = wimfs_get_context();
2123
2124         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
2125                               &dentry, &lte, &stream_idx);
2126
2127         if (ret != 0)
2128                 return ret;
2129
2130         if (lte == NULL && size == 0)
2131                 return 0;
2132
2133         inode = dentry->d_inode;
2134         if (stream_idx == 0)
2135                 stream_id = 0;
2136         else
2137                 stream_id = inode->ads_entries[stream_idx - 1].stream_id;
2138
2139         if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
2140                 ret = truncate(lte->staging_file_name, size);
2141                 if (ret != 0)
2142                         ret = -errno;
2143         } else {
2144                 /* File in WIM.  Extract it to the staging directory, but only
2145                  * the first @size bytes of it. */
2146                 ret = extract_resource_to_staging_dir(inode, stream_id,
2147                                                       &lte, size, ctx);
2148         }
2149         return ret;
2150 }
2151
2152 /* Unlink a non-directory or alternate data stream */
2153 static int wimfs_unlink(const char *path)
2154 {
2155         struct dentry *dentry;
2156         struct lookup_table_entry *lte;
2157         int ret;
2158         u16 stream_idx;
2159         struct wimfs_context *ctx = wimfs_get_context();
2160
2161         ret = lookup_resource(ctx->wim, path, get_lookup_flags(ctx),
2162                               &dentry, &lte, &stream_idx);
2163
2164         if (ret != 0)
2165                 return ret;
2166
2167         if (stream_idx == 0)
2168                 remove_dentry(dentry, ctx->wim->lookup_table);
2169         else
2170                 inode_remove_ads(dentry->d_inode, stream_idx - 1,
2171                                  ctx->wim->lookup_table);
2172         return 0;
2173 }
2174
2175 #ifdef HAVE_UTIMENSAT
2176 /*
2177  * Change the timestamp on a file dentry.
2178  *
2179  * Note that alternate data streams do not have their own timestamps.
2180  */
2181 static int wimfs_utimens(const char *path, const struct timespec tv[2])
2182 {
2183         struct dentry *dentry;
2184         struct inode *inode;
2185         WIMStruct *w = wimfs_get_WIMStruct();
2186
2187         dentry = get_dentry(w, path);
2188         if (!dentry)
2189                 return -ENOENT;
2190         inode = dentry->d_inode;
2191
2192         if (tv[0].tv_nsec != UTIME_OMIT) {
2193                 if (tv[0].tv_nsec == UTIME_NOW)
2194                         inode->last_access_time = get_wim_timestamp();
2195                 else
2196                         inode->last_access_time = timespec_to_wim_timestamp(&tv[0]);
2197         }
2198         if (tv[1].tv_nsec != UTIME_OMIT) {
2199                 if (tv[1].tv_nsec == UTIME_NOW)
2200                         inode->last_write_time = get_wim_timestamp();
2201                 else
2202                         inode->last_write_time = timespec_to_wim_timestamp(&tv[1]);
2203         }
2204         return 0;
2205 }
2206 #else
2207 static int wimfs_utime(const char *path, struct utimbuf *times)
2208 {
2209         struct dentry *dentry;
2210         struct inode *inode;
2211         WIMStruct *w = wimfs_get_WIMStruct();
2212
2213         dentry = get_dentry(w, path);
2214         if (!dentry)
2215                 return -ENOENT;
2216         inode = dentry->d_inode;
2217
2218         inode->last_write_time = unix_timestamp_to_wim(times->modtime);
2219         inode->last_access_time = unix_timestamp_to_wim(times->actime);
2220         return 0;
2221 }
2222 #endif
2223
2224 /* Writes to a file in the WIM filesystem.
2225  * It may be an alternate data stream, but here we don't even notice because we
2226  * just get a lookup table entry. */
2227 static int wimfs_write(const char *path, const char *buf, size_t size,
2228                        off_t offset, struct fuse_file_info *fi)
2229 {
2230         struct wimlib_fd *fd = (struct wimlib_fd*)(uintptr_t)fi->fh;
2231         int ret;
2232         u64 now;
2233
2234         if (!fd)
2235                 return -EBADF;
2236
2237         wimlib_assert(fd->f_lte);
2238         wimlib_assert(fd->f_lte->staging_file_name);
2239         wimlib_assert(fd->staging_fd != -1);
2240         wimlib_assert(fd->f_inode);
2241
2242         /* Seek to the requested position */
2243         if (lseek(fd->staging_fd, offset, SEEK_SET) == -1)
2244                 return -errno;
2245
2246         /* Write the data. */
2247         ret = write(fd->staging_fd, buf, size);
2248         if (ret == -1)
2249                 return -errno;
2250
2251         now = get_wim_timestamp();
2252         fd->f_inode->last_write_time = now;
2253         fd->f_inode->last_access_time = now;
2254         return ret;
2255 }
2256
2257 static struct fuse_operations wimfs_operations = {
2258         .access      = wimfs_access,
2259         .chmod       = wimfs_chmod,
2260         .destroy     = wimfs_destroy,
2261 #if 0
2262         .fallocate   = wimfs_fallocate,
2263 #endif
2264         .fgetattr    = wimfs_fgetattr,
2265         .ftruncate   = wimfs_ftruncate,
2266         .getattr     = wimfs_getattr,
2267 #ifdef ENABLE_XATTR
2268         .getxattr    = wimfs_getxattr,
2269 #endif
2270         .link        = wimfs_link,
2271 #ifdef ENABLE_XATTR
2272         .listxattr   = wimfs_listxattr,
2273 #endif
2274         .mkdir       = wimfs_mkdir,
2275         .mknod       = wimfs_mknod,
2276         .open        = wimfs_open,
2277         .opendir     = wimfs_opendir,
2278         .read        = wimfs_read,
2279         .readdir     = wimfs_readdir,
2280         .readlink    = wimfs_readlink,
2281         .release     = wimfs_release,
2282         .releasedir  = wimfs_releasedir,
2283 #ifdef ENABLE_XATTR
2284         .removexattr = wimfs_removexattr,
2285 #endif
2286         .rename      = wimfs_rename,
2287         .rmdir       = wimfs_rmdir,
2288 #ifdef ENABLE_XATTR
2289         .setxattr    = wimfs_setxattr,
2290 #endif
2291         .symlink     = wimfs_symlink,
2292         .truncate    = wimfs_truncate,
2293         .unlink      = wimfs_unlink,
2294 #ifdef HAVE_UTIMENSAT
2295         .utimens     = wimfs_utimens,
2296 #else
2297         .utime       = wimfs_utime,
2298 #endif
2299         .write       = wimfs_write,
2300
2301 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
2302         .flag_nullpath_ok = 1,
2303 #endif
2304 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 9)
2305         .flag_nopath = 1,
2306         .flag_utime_omit_ok = 1,
2307 #endif
2308 };
2309
2310
2311 /* Mounts an image from a WIM file. */
2312 WIMLIBAPI int wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
2313                                  int mount_flags, WIMStruct **additional_swms,
2314                                  unsigned num_additional_swms,
2315                                  const char *staging_dir)
2316 {
2317         int argc = 0;
2318         char *argv[16];
2319         int ret;
2320         char *dir_copy;
2321         struct lookup_table *joined_tab, *wim_tab_save;
2322         struct image_metadata *imd;
2323         struct wimfs_context ctx;
2324         struct hlist_node *cur_node;
2325         struct inode *inode;
2326
2327         DEBUG("Mount: wim = %p, image = %d, dir = %s, flags = %d, ",
2328               wim, image, dir, mount_flags);
2329
2330         if (!wim || !dir)
2331                 return WIMLIB_ERR_INVALID_PARAM;
2332
2333         ret = verify_swm_set(wim, additional_swms, num_additional_swms);
2334         if (ret != 0)
2335                 return ret;
2336
2337         if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) && (wim->hdr.total_parts != 1)) {
2338                 ERROR("Cannot mount a split WIM read-write");
2339                 return WIMLIB_ERR_SPLIT_UNSUPPORTED;
2340         }
2341
2342         if (num_additional_swms) {
2343                 ret = new_joined_lookup_table(wim, additional_swms,
2344                                               num_additional_swms,
2345                                               &joined_tab);
2346                 if (ret != 0)
2347                         return ret;
2348                 wim_tab_save = wim->lookup_table;
2349                 wim->lookup_table = joined_tab;
2350         }
2351
2352         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2353                 ret = wim_run_full_verifications(wim);
2354                 if (ret != 0)
2355                         goto out;
2356         }
2357
2358         ret = select_wim_image(wim, image);
2359         if (ret != 0)
2360                 goto out;
2361
2362         DEBUG("Selected image %d", image);
2363
2364         imd = wim_get_current_image_metadata(wim);
2365
2366         if (imd->root_dentry->refcnt != 1) {
2367                 ERROR("Cannot mount image that was just exported with "
2368                       "wimlib_export_image()");
2369                 ret = WIMLIB_ERR_INVALID_PARAM;
2370                 goto out;
2371         }
2372
2373         if (imd->inode_list.first)
2374                 imd->inode_list.first->pprev = &imd->inode_list.first;
2375
2376         if (imd->modified) {
2377                 ERROR("Cannot mount image that was added "
2378                       "with wimlib_add_image()");
2379                 ret = WIMLIB_ERR_INVALID_PARAM;
2380                 goto out;
2381         }
2382
2383         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2384                 ret = lock_wim(wim, wim->fp);
2385                 if (ret != 0)
2386                         goto out;
2387         }
2388
2389         if (!(mount_flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
2390                        WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
2391                        WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)))
2392                 mount_flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
2393
2394
2395         DEBUG("Initializing struct wimfs_context");
2396         init_wimfs_context(&ctx);
2397         ctx.wim = wim;
2398         ctx.mount_flags = mount_flags;
2399         ctx.image_inode_list = &imd->inode_list;
2400
2401         if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
2402                 ctx.default_lookup_flags = LOOKUP_FLAG_ADS_OK;
2403
2404         DEBUG("Unlinking message queues in case they already exist");
2405         ret = set_message_queue_names(&ctx, dir);
2406         if (ret != 0)
2407                 goto out_unlock;
2408         unlink_message_queues(&ctx);
2409
2410         DEBUG("Preparing arguments to fuse_main()");
2411
2412         dir_copy = STRDUP(dir);
2413         if (!dir_copy)
2414                 goto out_free_message_queue_names;
2415
2416         argv[argc++] = "imagex";
2417         argv[argc++] = dir_copy;
2418
2419         /* disable multi-threaded operation for read-write mounts */
2420         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)
2421                 argv[argc++] = "-s";
2422
2423         if (mount_flags & WIMLIB_MOUNT_FLAG_DEBUG)
2424                 argv[argc++] = "-d";
2425
2426         /*
2427          * We provide the use_ino option because we are going to assign inode
2428          * numbers oursides.  The inodes will be given unique numbers in the
2429          * assign_inode_numbers() function, and the static variable @next_ino is
2430          * set to the next available inode number.
2431          */
2432         char optstring[256] =
2433                 "use_ino"
2434                 ",subtype=wimfs"
2435                 ",attr_timeout=0"
2436 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
2437                 ",hard_remove"
2438 #endif
2439                 ;
2440         argv[argc++] = "-o";
2441         argv[argc++] = optstring;
2442         if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)) {
2443                 /* Read-write mount.  Make the staging directory */
2444                 ret = make_staging_dir(&ctx, staging_dir);
2445                 if (ret != 0)
2446                         goto out_free_dir_copy;
2447         } else {
2448                 /* Read-only mount */
2449                 strcat(optstring, ",ro");
2450         }
2451         argv[argc] = NULL;
2452
2453 #ifdef ENABLE_DEBUG
2454         {
2455                 int i;
2456                 DEBUG("FUSE command line (argc = %d): ", argc);
2457                 for (i = 0; i < argc; i++) {
2458                         fputs(argv[i], stdout);
2459                         putchar(' ');
2460                 }
2461                 putchar('\n');
2462                 fflush(stdout);
2463         }
2464 #endif
2465
2466         /* Mark dentry tree as modified if read-write mount. */
2467         if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2468                 imd->modified = 1;
2469                 imd->has_been_mounted_rw = 1;
2470         }
2471
2472         /* Resolve the lookup table entries for every inode in the image, and
2473          * assign inode numbers */
2474         DEBUG("Resolving lookup table entries and assigning inode numbers");
2475
2476         ctx.next_ino = 1;
2477         hlist_for_each_entry(inode, cur_node, &imd->inode_list, hlist) {
2478                 inode_resolve_ltes(inode, wim->lookup_table);
2479                 inode->ino = ctx.next_ino++;
2480         }
2481         /*ctx.next_ino = assign_inode_numbers(&imd->inode_list);*/
2482         DEBUG("(next_ino = %"PRIu64")", ctx.next_ino);
2483
2484         DEBUG("Calling fuse_main()");
2485
2486         ret = fuse_main(argc, argv, &wimfs_operations, &ctx);
2487
2488         DEBUG("Returned from fuse_main() (ret = %d)", ret);
2489         if (ret)
2490                 ret = WIMLIB_ERR_FUSE;
2491 out_free_dir_copy:
2492         FREE(dir_copy);
2493 out_unlock:
2494         wim->wim_locked = 0;
2495 out_free_message_queue_names:
2496         free_message_queue_names(&ctx);
2497 out:
2498         if (num_additional_swms) {
2499                 free_lookup_table(wim->lookup_table);
2500                 wim->lookup_table = wim_tab_save;
2501         }
2502         return ret;
2503 }
2504
2505 /*
2506  * Unmounts the WIM file that was previously mounted on @dir by using
2507  * wimlib_mount_image().
2508  */
2509 WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
2510                                    wimlib_progress_func_t progress_func)
2511 {
2512         int ret;
2513         struct wimfs_context wimfs_ctx;
2514
2515         init_wimfs_context(&wimfs_ctx);
2516
2517         ret = set_message_queue_names(&wimfs_ctx, dir);
2518         if (ret != 0)
2519                 goto out;
2520
2521         ret = open_message_queues(&wimfs_ctx, false);
2522         if (ret != 0)
2523                 goto out_free_message_queue_names;
2524
2525         ret = send_unmount_request_msg(wimfs_ctx.unmount_to_daemon_mq,
2526                                        unmount_flags,
2527                                        progress_func != NULL);
2528         if (ret != 0)
2529                 goto out_close_message_queues;
2530
2531         ret = execute_fusermount(dir);
2532         if (ret != 0)
2533                 goto out_close_message_queues;
2534
2535         struct unmount_msg_handler_context handler_ctx = {
2536                 .hdr = {
2537                         .timeout_seconds = 5,
2538                 },
2539                 .daemon_pid = 0,
2540                 .progress_func = progress_func,
2541         };
2542
2543         ret = message_loop(wimfs_ctx.daemon_to_unmount_mq,
2544                            &unmount_msg_handler_callbacks,
2545                            &handler_ctx.hdr);
2546         if (ret == 0)
2547                 ret = handler_ctx.status;
2548 out_close_message_queues:
2549         close_message_queues(&wimfs_ctx);
2550 out_free_message_queue_names:
2551         free_message_queue_names(&wimfs_ctx);
2552 out:
2553         return ret;
2554 }
2555
2556 #else /* WITH_FUSE */
2557
2558
2559 static inline int mount_unsupported_error()
2560 {
2561         ERROR("wimlib was compiled with --without-fuse, which disables support "
2562               "for mounting WIMs.");
2563         return WIMLIB_ERR_UNSUPPORTED;
2564 }
2565
2566 WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
2567                                    wimlib_progress_func_t progress_func)
2568 {
2569         return mount_unsupported_error();
2570 }
2571
2572 WIMLIBAPI int wimlib_mount_image(WIMStruct *wim_p, int image, const char *dir,
2573                                  int mount_flags, WIMStruct **additional_swms,
2574                                  unsigned num_additional_swms,
2575                                  const char *staging_dir)
2576 {
2577         return mount_unsupported_error();
2578 }
2579
2580 #endif /* WITH_FUSE */