1 /*
2 * mount_image.c
3 *
4 * This file implements mounting of WIM images using FUSE
5 * (Filesystem in Userspace). See http://fuse.sourceforge.net/.
6 *
7 * Currently it is only expected to work on Linux.
8 */
9
10 /*
11 * Copyright (C) 2012-2016 Eric Biggers
12 *
13 * This file is free software; you can redistribute it and/or modify it under
14 * the terms of the GNU Lesser General Public License as published by the Free
15 * Software Foundation; either version 3 of the License, or (at your option) any
16 * later version.
17 *
18 * This file is distributed in the hope that it will be useful, but WITHOUT
19 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
20 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
21 * details.
22 *
23 * You should have received a copy of the GNU Lesser General Public License
24 * along with this file; if not, see http://www.gnu.org/licenses/.
25 */
26
27 #ifdef HAVE_CONFIG_H
28 # include "config.h"
29 #endif
30
31 #include "wimlib.h"
32 #include "wimlib/error.h"
33
34 #ifdef WITH_FUSE
35
36 #ifdef __WIN32__
37 # error "FUSE mount not supported on Windows! Please configure --without-fuse"
38 #endif
39
40 #define FUSE_USE_VERSION 26
41
42 #include <sys/types.h> /* sometimes required before <sys/xattr.h> */
43 #include <sys/xattr.h>
44 #include <dirent.h>
45 #include <errno.h>
46 #include <fuse.h>
47 #include <limits.h>
48 #include <mqueue.h>
49 #include <pthread.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <sys/stat.h>
53 #include <sys/time.h>
54 #include <unistd.h>
55 #include <utime.h>
56
57 #include "wimlib/blob_table.h"
58 #include "wimlib/dentry.h"
59 #include "wimlib/encoding.h"
60 #include "wimlib/metadata.h"
61 #include "wimlib/paths.h"
62 #include "wimlib/progress.h"
63 #include "wimlib/reparse.h"
64 #include "wimlib/timestamp.h"
65 #include "wimlib/unix_data.h"
66 #include "wimlib/write.h"
67 #include "wimlib/xml.h"
68
69 #ifndef O_NOFOLLOW
70 # define O_NOFOLLOW 0 /* Security only... */
71 #endif
72
73 #ifndef ENOATTR
74 # define ENOATTR ENODATA
75 #endif
76
77 #define WIMFS_MQUEUE_NAME_LEN 32
78
79 #define WIMLIB_UNMOUNT_FLAG_SEND_PROGRESS 0x80000000
80
81 struct wimfs_unmount_info {
82 unsigned unmount_flags;
83 char mq_name[WIMFS_MQUEUE_NAME_LEN + 1];
84 };
85
86 struct commit_progress_report {
87 enum wimlib_progress_msg msg;
88 union wimlib_progress_info info;
89 };
90
91 /* Description of an open file on a mounted WIM image. Actually, this
92 * represents the open state of a particular data stream of an inode, rather
93 * than the inode itself. (An inode might have multiple named data streams in
94 * addition to the default, unnamed data stream.) At a given time, an inode in
95 * the WIM image might have multiple file descriptors open to it, each to any
96 * one of its data streams. */
97 struct wimfs_fd {
98
99 /* Pointer to the inode of this open file.
100 * 'i_num_opened_fds' of the inode tracks the number of file descriptors
101 * that reference it. */
102 struct wim_inode *f_inode;
103
104 /* Pointer to the blob descriptor for the data stream that has been
105 * opened. 'num_opened_fds' of the blob descriptor tracks the number of
106 * file descriptors that reference it. Or, this value may be NULL,
107 * which indicates that the opened stream is empty and consequently does
108 * not have a blob descriptor. */
109 struct blob_descriptor *f_blob;
110
111 /* If valid (filedes_valid(&f_staging_fd)), this contains the
112 * corresponding native file descriptor for the staging file that has
113 * been created for reading from and/or writing to this open stream. A
114 * single staging file might have multiple file descriptors open to it
115 * simultaneously, each used by a different 'struct wimfs_fd'.
116 *
117 * Or, if invalid (!filedes_valid(&f_staging_fd)), this 'struct
118 * wimfs_fd' is not associated with a staging file. This is permissible
119 * only if this 'struct wimfs_fd' was opened read-only and the stream
120 * has not yet been extracted to a staging file. */
121 struct filedes f_staging_fd;
122
123 /* 0-based index of this file descriptor in the file descriptor table of
124 * its inode. */
125 u16 f_idx;
126
127 /* Unique ID of the opened stream in the inode. This will stay the same
128 * even if the indices of the inode's streams are changed by a deletion.
129 */
130 u32 f_stream_id;
131 };
132
133 #define WIMFS_FD(fi) ((struct wimfs_fd *)(uintptr_t)((fi)->fh))
134
135 /* Context structure for a mounted WIM image. */
136 struct wimfs_context {
137 /* The WIMStruct containing the mounted image. The mounted image is the
138 * currently selected image (wim->current_image). */
139 WIMStruct *wim;
140
141 /* Flags passed to wimlib_mount_image() (WIMLIB_MOUNT_FLAG_*). */
142 int mount_flags;
143
144 /* Default flags for path lookup in the WIM image. */
145 int default_lookup_flags;
146
147 /* Information about the user who has mounted the WIM image */
148 uid_t owner_uid;
149 gid_t owner_gid;
150
151 /* Absolute path to the mountpoint directory (may be needed for absolute
152 * symbolic link fixups) */
153 char *mountpoint_abspath;
154 size_t mountpoint_abspath_nchars;
155
156 /* Information about the staging directory for a read-write mount. */
157 int parent_dir_fd;
158 int staging_dir_fd;
159 char *staging_dir_name;
160
161 /* For read-write mounts, the inode number to be assigned to the next
162 * created file. Note: since this isn't a persistent filesystem and we
163 * can re-assign the inode numbers just before mounting the image, it's
164 * good enough to just generate inode numbers sequentially. */
165 u64 next_ino;
166
167 /* Number of file descriptors open to the mounted WIM image. */
168 unsigned long num_open_fds;
169
170 /* For read-write mounts, the original metadata resource of the mounted
171 * image. */
172 struct blob_descriptor *metadata_resource;
173
174 /* Parameters for unmounting the image (can be set via extended
175 * attribute "wimfs.unmount_info"). */
176 struct wimfs_unmount_info unmount_info;
177 };
178
179 #define WIMFS_CTX(fuse_ctx) ((struct wimfs_context*)(fuse_ctx)->private_data)
180
181 /* Retrieve the context structure for the currently mounted WIM image.
182 *
183 * Note: this is a per-thread variable. It is possible for different threads to
184 * mount different images at the same time in the same process, although they
185 * must use different WIMStructs! */
186 static inline struct wimfs_context *
wimfs_get_context(void)187 wimfs_get_context(void)
188 {
189 return WIMFS_CTX(fuse_get_context());
190 }
191
192 static void
wimfs_inc_num_open_fds(void)193 wimfs_inc_num_open_fds(void)
194 {
195 wimfs_get_context()->num_open_fds++;
196 }
197
198 static void
wimfs_dec_num_open_fds(void)199 wimfs_dec_num_open_fds(void)
200 {
201 wimfs_get_context()->num_open_fds--;
202 }
203
204 /* Retrieve the WIMStruct for the currently mounted WIM image. */
205 static inline WIMStruct *
wimfs_get_WIMStruct(void)206 wimfs_get_WIMStruct(void)
207 {
208 return wimfs_get_context()->wim;
209 }
210
211 /* Is write permission requested on the file? */
212 static inline bool
flags_writable(int open_flags)213 flags_writable(int open_flags)
214 {
215 int accmode = (open_flags & O_ACCMODE);
216 return (accmode == O_RDWR || accmode == O_WRONLY);
217 }
218
219 static mode_t
fuse_mask_mode(mode_t mode,const struct fuse_context * fuse_ctx)220 fuse_mask_mode(mode_t mode, const struct fuse_context *fuse_ctx)
221 {
222 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
223 mode &= ~fuse_ctx->umask;
224 #endif
225 return mode;
226 }
227
228 /*
229 * Allocate a file descriptor to a data stream in the mounted WIM image.
230 *
231 * @inode
232 * The inode containing the stream being opened
233 * @strm
234 * The stream of the inode being opened
235 * @fd_ret
236 * On success, a pointer to the new file descriptor will be stored here.
237 *
238 * Returns 0 or a -errno code.
239 */
240 static int
alloc_wimfs_fd(struct wim_inode * inode,struct wim_inode_stream * strm,struct wimfs_fd ** fd_ret)241 alloc_wimfs_fd(struct wim_inode *inode,
242 struct wim_inode_stream *strm,
243 struct wimfs_fd **fd_ret)
244 {
245 static const u16 min_fds_per_alloc = 8;
246 static const u16 max_fds = 0xffff;
247 u16 i;
248 struct wimfs_fd *fd;
249
250 if (inode->i_num_opened_fds == inode->i_num_allocated_fds) {
251 u16 num_new_fds;
252 struct wimfs_fd **fds;
253
254 /* Expand this inode's file descriptor table. */
255
256 num_new_fds = max(min_fds_per_alloc,
257 inode->i_num_allocated_fds / 4);
258
259 num_new_fds = min(num_new_fds,
260 max_fds - inode->i_num_allocated_fds);
261
262 if (num_new_fds == 0)
263 return -EMFILE;
264
265 fds = REALLOC(inode->i_fds,
266 (inode->i_num_allocated_fds + num_new_fds) *
267 sizeof(fds[0]));
268 if (!fds)
269 return -ENOMEM;
270
271 memset(&fds[inode->i_num_allocated_fds], 0,
272 num_new_fds * sizeof(fds[0]));
273 inode->i_fds = fds;
274 inode->i_num_allocated_fds += num_new_fds;
275 inode->i_next_fd = inode->i_num_opened_fds;
276 }
277
278 /* Allocate the file descriptor in the first available space in the
279 * inode's file descriptor table.
280 *
281 * i_next_fd is the lower bound on the next open slot. */
282 for (i = inode->i_next_fd; inode->i_fds[i]; i++)
283 ;
284
285 fd = MALLOC(sizeof(*fd));
286 if (!fd)
287 return -ENOMEM;
288
289 fd->f_inode = inode;
290 fd->f_blob = stream_blob_resolved(strm);
291 filedes_invalidate(&fd->f_staging_fd);
292 fd->f_idx = i;
293 fd->f_stream_id = strm->stream_id;
294 *fd_ret = fd;
295 inode->i_fds[i] = fd;
296 inode->i_num_opened_fds++;
297 if (fd->f_blob)
298 fd->f_blob->num_opened_fds++;
299 wimfs_inc_num_open_fds();
300 inode->i_next_fd = i + 1;
301 return 0;
302 }
303
304 /*
305 * Close a file descriptor to a data stream in the mounted WIM image.
306 *
307 * Returns 0 or a -errno code. The file descriptor is always closed.
308 */
309 static int
close_wimfs_fd(struct wimfs_fd * fd)310 close_wimfs_fd(struct wimfs_fd *fd)
311 {
312 int ret = 0;
313 struct wim_inode *inode;
314
315 /* Close the staging file if open. */
316 if (filedes_valid(&fd->f_staging_fd))
317 if (filedes_close(&fd->f_staging_fd))
318 ret = -errno;
319
320 /* Release this file descriptor from its blob descriptor. */
321 if (fd->f_blob)
322 blob_decrement_num_opened_fds(fd->f_blob);
323
324 wimfs_dec_num_open_fds();
325
326 /* Release this file descriptor from its inode. */
327 inode = fd->f_inode;
328 inode->i_fds[fd->f_idx] = NULL;
329 if (fd->f_idx < inode->i_next_fd)
330 inode->i_next_fd = fd->f_idx;
331 FREE(fd);
332 inode_dec_num_opened_fds(inode);
333 return ret;
334 }
335
336 /*
337 * Translate a path into the corresponding inode in the mounted WIM image.
338 *
339 * See get_dentry() for more information.
340 *
341 * Returns a pointer to the resulting inode, or NULL with errno set.
342 */
343 static struct wim_inode *
wim_pathname_to_inode(WIMStruct * wim,const char * path)344 wim_pathname_to_inode(WIMStruct *wim, const char *path)
345 {
346 struct wim_dentry *dentry;
347
348 dentry = get_dentry(wim, path, WIMLIB_CASE_SENSITIVE);
349 if (!dentry)
350 return NULL;
351 return dentry->d_inode;
352 }
353
354 /* Can look up named data stream with colon syntax */
355 #define LOOKUP_FLAG_ADS_OK 0x01
356
357 /* Can look up directory (otherwise get -ENOTDIR) */
358 #define LOOKUP_FLAG_DIRECTORY_OK 0x02
359
360 /* Get the data stream of the specified name from the specified inode. Returns
361 * NULL with errno set if not found. */
362 static struct wim_inode_stream *
inode_get_data_stream_tstr(const struct wim_inode * inode,const char * stream_name)363 inode_get_data_stream_tstr(const struct wim_inode *inode,
364 const char *stream_name)
365 {
366 struct wim_inode_stream *strm;
367
368 if (!stream_name || !*stream_name) {
369 strm = inode_get_unnamed_data_stream(inode);
370 } else {
371 const utf16lechar *uname;
372
373 if (tstr_get_utf16le(stream_name, &uname))
374 return NULL;
375 strm = inode_get_stream(inode, STREAM_TYPE_DATA, uname);
376 tstr_put_utf16le(uname);
377 }
378 if (!strm)
379 errno = ENOENT;
380 return strm;
381 }
382
383 /*
384 * Translate a path into the corresponding dentry and stream in the mounted WIM
385 * image.
386 *
387 * Returns 0 or a -errno code. @dentry_ret and @strm_ret are both optional.
388 */
389 static int
wim_pathname_to_stream(const struct wimfs_context * ctx,const char * path,int lookup_flags,struct wim_dentry ** dentry_ret,struct wim_inode_stream ** strm_ret)390 wim_pathname_to_stream(const struct wimfs_context *ctx,
391 const char *path,
392 int lookup_flags,
393 struct wim_dentry **dentry_ret,
394 struct wim_inode_stream **strm_ret)
395 {
396 WIMStruct *wim = ctx->wim;
397 struct wim_dentry *dentry;
398 struct wim_inode *inode;
399 struct wim_inode_stream *strm;
400 const char *stream_name = NULL;
401 char *p = NULL;
402
403 lookup_flags |= ctx->default_lookup_flags;
404
405 if (lookup_flags & LOOKUP_FLAG_ADS_OK) {
406 stream_name = path_stream_name(path);
407 if (stream_name) {
408 p = (char *)stream_name - 1;
409 *p = '\0';
410 }
411 }
412
413 dentry = get_dentry(wim, path, WIMLIB_CASE_SENSITIVE);
414 if (p)
415 *p = ':';
416 if (!dentry)
417 return -errno;
418
419 inode = dentry->d_inode;
420
421 if (inode_resolve_streams(inode, wim->blob_table, false))
422 return -EIO;
423
424 if (!(lookup_flags & LOOKUP_FLAG_DIRECTORY_OK)
425 && inode_is_directory(inode))
426 return -EISDIR;
427
428 strm = inode_get_data_stream_tstr(inode, stream_name);
429 if (!strm) {
430 /* Force creation of an unnamed data stream */
431 if (!stream_name)
432 strm = inode_add_stream(inode, STREAM_TYPE_DATA,
433 NO_STREAM_NAME, NULL);
434 if (!strm)
435 return -errno;
436 }
437
438 if (dentry_ret)
439 *dentry_ret = dentry;
440 if (strm_ret)
441 *strm_ret = strm;
442 return 0;
443 }
444
445 /*
446 * Create a new file in the mounted WIM image.
447 *
448 * @fuse_ctx
449 * The FUSE context for the mounted image.
450 * @path
451 * The path at which to create the first link to the new file. If a file
452 * already exists at this path, -EEXIST is returned.
453 * @mode
454 * The UNIX mode for the new file. This is only fully honored if
455 * WIMLIB_MOUNT_FLAG_UNIX_DATA was passed to wimlib_mount_image().
456 * @rdev
457 * The device ID for the new file, encoding the major and minor device
458 * numbers. This is only honored if WIMLIB_MOUNT_FLAG_UNIX_DATA was passed
459 * to wimlib_mount_image().
460 * @dentry_ret
461 * On success, a pointer to the new dentry is returned here. Its d_inode
462 * member will point to the new inode that was created for it and added to
463 * the mounted WIM image.
464 *
465 * Returns 0 or a -errno code.
466 */
467 static int
create_file(struct fuse_context * fuse_ctx,const char * path,mode_t mode,dev_t rdev,struct wim_dentry ** dentry_ret)468 create_file(struct fuse_context *fuse_ctx, const char *path,
469 mode_t mode, dev_t rdev, struct wim_dentry **dentry_ret)
470 {
471 struct wimfs_context *wimfs_ctx = WIMFS_CTX(fuse_ctx);
472 struct wim_dentry *parent;
473 const char *basename;
474 struct wim_dentry *dentry;
475 struct wim_inode *inode;
476
477 parent = get_parent_dentry(wimfs_ctx->wim, path, WIMLIB_CASE_SENSITIVE);
478 if (!parent)
479 return -errno;
480
481 if (!dentry_is_directory(parent))
482 return -ENOTDIR;
483
484 basename = path_basename(path);
485
486 if (get_dentry_child_with_name(parent, basename, WIMLIB_CASE_SENSITIVE))
487 return -EEXIST;
488
489 if (new_dentry_with_new_inode(basename, true, &dentry))
490 return -ENOMEM;
491
492 inode = dentry->d_inode;
493
494 inode->i_ino = wimfs_ctx->next_ino++;
495
496 /* Note: we still use FILE_ATTRIBUTE_NORMAL for device nodes, named
497 * pipes, and sockets. The real mode is in the UNIX metadata. */
498 if (S_ISDIR(mode))
499 inode->i_attributes = FILE_ATTRIBUTE_DIRECTORY;
500 else
501 inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
502
503 if (wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_UNIX_DATA) {
504 struct wimlib_unix_data unix_data;
505
506 unix_data.uid = fuse_ctx->uid;
507 unix_data.gid = fuse_ctx->gid;
508 unix_data.mode = fuse_mask_mode(mode, fuse_ctx);
509 unix_data.rdev = rdev;
510 if (!inode_set_unix_data(inode, &unix_data, UNIX_DATA_ALL))
511 {
512 free_dentry(dentry);
513 return -ENOMEM;
514 }
515 }
516
517 hlist_add_head(&inode->i_hlist_node,
518 &wim_get_current_image_metadata(wimfs_ctx->wim)->inode_list);
519
520 dentry_add_child(parent, dentry);
521
522 *dentry_ret = dentry;
523 return 0;
524 }
525
526 /*
527 * Remove a dentry from the mounted WIM image; i.e. remove an alias for an
528 * inode.
529 */
530 static void
remove_dentry(struct wim_dentry * dentry,struct blob_table * blob_table)531 remove_dentry(struct wim_dentry *dentry, struct blob_table *blob_table)
532 {
533 /* Drop blob references. */
534 inode_unref_blobs(dentry->d_inode, blob_table);
535
536 /* Unlink the dentry from the image's dentry tree. */
537 unlink_dentry(dentry);
538
539 /* Delete the dentry. This will also decrement the link count of the
540 * corresponding inode, and possibly cause it to be deleted as well. */
541 free_dentry(dentry);
542 }
543
544 /* Generate UNIX filetype mode bits for the specified WIM inode, based on its
545 * Windows file attributes. */
546 static mode_t
inode_unix_file_type(const struct wim_inode * inode)547 inode_unix_file_type(const struct wim_inode *inode)
548 {
549 if (inode_is_symlink(inode))
550 return S_IFLNK;
551 else if (inode_is_directory(inode))
552 return S_IFDIR;
553 else
554 return S_IFREG;
555 }
556
557 /* Generate a default UNIX mode for the specified WIM inode. */
558 static mode_t
inode_default_unix_mode(const struct wim_inode * inode)559 inode_default_unix_mode(const struct wim_inode *inode)
560 {
561 return inode_unix_file_type(inode) | 0777;
562 }
563
564 static u64
blob_size(const struct blob_descriptor * blob)565 blob_size(const struct blob_descriptor *blob)
566 {
567 if (!blob)
568 return 0;
569 return blob->size;
570 }
571
572 static u64
blob_stored_size(const struct blob_descriptor * blob)573 blob_stored_size(const struct blob_descriptor *blob)
574 {
575 if (!blob)
576 return 0;
577 if (blob->blob_location == BLOB_IN_WIM &&
578 blob->size == blob->rdesc->uncompressed_size)
579 return blob->rdesc->size_in_wim;
580 return blob->size;
581 }
582
583 /*
584 * Retrieve standard UNIX metadata ('struct stat') for a WIM inode.
585 *
586 * @blob is the blob descriptor for the stream of the inode that is being
587 * queried, or NULL. We mostly return the same information for all streams, but
588 * st_size and st_blocks may be different for different streams.
589 *
590 * This always returns 0.
591 */
592 static int
inode_to_stbuf(const struct wim_inode * inode,const struct blob_descriptor * blob,struct stat * stbuf)593 inode_to_stbuf(const struct wim_inode *inode,
594 const struct blob_descriptor *blob, struct stat *stbuf)
595 {
596 const struct wimfs_context *ctx = wimfs_get_context();
597 struct wimlib_unix_data unix_data;
598
599 memset(stbuf, 0, sizeof(struct stat));
600 if ((ctx->mount_flags & WIMLIB_MOUNT_FLAG_UNIX_DATA) &&
601 inode_get_unix_data(inode, &unix_data))
602 {
603 /* Use the user ID, group ID, mode, and device ID from the
604 * inode's extra UNIX metadata information. */
605 stbuf->st_uid = unix_data.uid;
606 stbuf->st_gid = unix_data.gid;
607 stbuf->st_mode = unix_data.mode;
608 stbuf->st_rdev = unix_data.rdev;
609 } else {
610 /* Generate default values for the user ID, group ID, and mode.
611 *
612 * Note: in the case of an allow_other mount, fuse_context.uid
613 * may not be the same as wimfs_context.owner_uid! */
614 stbuf->st_uid = ctx->owner_uid;
615 stbuf->st_gid = ctx->owner_gid;
616 stbuf->st_mode = inode_default_unix_mode(inode);
617 }
618 stbuf->st_ino = inode->i_ino;
619 stbuf->st_nlink = inode->i_nlink;
620 stbuf->st_size = blob_size(blob);
621 #ifdef HAVE_STAT_NANOSECOND_PRECISION
622 stbuf->st_atim = wim_timestamp_to_timespec(inode->i_last_access_time);
623 stbuf->st_mtim = wim_timestamp_to_timespec(inode->i_last_write_time);
624 stbuf->st_ctim = stbuf->st_mtim;
625 #else
626 stbuf->st_atime = wim_timestamp_to_time_t(inode->i_last_access_time);
627 stbuf->st_mtime = wim_timestamp_to_time_t(inode->i_last_write_time);
628 stbuf->st_ctime = stbuf->st_mtime;
629 #endif
630 stbuf->st_blocks = DIV_ROUND_UP(blob_stored_size(blob), 512);
631 return 0;
632 }
633
634 /* Update the last access and last write timestamps of a WIM inode. */
635 static void
touch_inode(struct wim_inode * inode)636 touch_inode(struct wim_inode *inode)
637 {
638 u64 now = now_as_wim_timestamp();
639 inode->i_last_access_time = now;
640 inode->i_last_write_time = now;
641 }
642
643 static void
touch_parent(struct wim_dentry * dentry)644 touch_parent(struct wim_dentry *dentry)
645 {
646 touch_inode(dentry->d_parent->d_inode);
647 }
648
649 /*
650 * Create a new file in the staging directory for a read-write mounted image.
651 *
652 * On success, returns the file descriptor for the new staging file, opened for
653 * writing. In addition, stores the allocated name of the staging file in
654 * @name_ret.
655 *
656 * On failure, returns -1 and sets errno.
657 */
658 static int
create_staging_file(const struct wimfs_context * ctx,char ** name_ret)659 create_staging_file(const struct wimfs_context *ctx, char **name_ret)
660 {
661
662 static const size_t STAGING_FILE_NAME_LEN = 20;
663 char *name;
664 int fd;
665
666 name = MALLOC(STAGING_FILE_NAME_LEN + 1);
667 if (!name)
668 return -1;
669 name[STAGING_FILE_NAME_LEN] = '\0';
670
671 retry:
672 get_random_alnum_chars(name, STAGING_FILE_NAME_LEN);
673 fd = openat(ctx->staging_dir_fd, name,
674 O_WRONLY | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
675 if (unlikely(fd < 0)) {
676 if (unlikely(errno == EEXIST))
677 /* Try again with another name. */
678 goto retry;
679 FREE(name);
680 } else {
681 *name_ret = name;
682 }
683 return fd;
684 }
685
686 /*
687 * Extract a blob to the staging directory. This is necessary when a stream
688 * using the blob is being opened for writing and the blob has not already been
689 * extracted to the staging directory.
690 *
691 * @inode
692 * The inode containing the stream being opened for writing.
693 * @strm
694 * The stream being opened for writing. The blob descriptor to which the
695 * stream refers will be changed by this function.
696 * @size
697 * Number of bytes of the blob to extract and include in the staging file.
698 * It may be less than the actual blob length, in which case only a prefix
699 * of the blob will be extracted. It may also be more than the actual blob
700 * length, in which case the extra space will be zero-filled.
701 *
702 * Returns 0 or a -errno code.
703 */
704 static int
extract_blob_to_staging_dir(struct wim_inode * inode,struct wim_inode_stream * strm,off_t size,const struct wimfs_context * ctx)705 extract_blob_to_staging_dir(struct wim_inode *inode,
706 struct wim_inode_stream *strm,
707 off_t size, const struct wimfs_context *ctx)
708 {
709 struct blob_descriptor *old_blob;
710 struct blob_descriptor *new_blob;
711 char *staging_file_name;
712 int staging_fd;
713 off_t extract_size;
714 int result;
715 int ret;
716
717 old_blob = stream_blob_resolved(strm);
718
719 /* Create the staging file. */
720 staging_fd = create_staging_file(ctx, &staging_file_name);
721 if (unlikely(staging_fd < 0))
722 return -errno;
723
724 /* Extract the stream to the staging file (possibly truncated). */
725 if (old_blob) {
726 struct filedes fd;
727
728 filedes_init(&fd, staging_fd);
729 errno = 0;
730 extract_size = min(old_blob->size, size);
731 result = extract_blob_prefix_to_fd(old_blob, extract_size, &fd);
732 } else {
733 extract_size = 0;
734 result = 0;
735 }
736
737 /* In the case of truncate() to more than the file length, extend the
738 * staging file with zeroes by calling ftruncate(). */
739 if (!result && size > extract_size)
740 result = ftruncate(staging_fd, size);
741
742 /* Close the staging file. */
743 if (close(staging_fd))
744 result = -1;
745
746 /* If an error occurred, unlink the staging file. */
747 if (unlikely(result)) {
748 /* extract_blob_to_fd() should set errno, but if it didn't,
749 * set a default value. */
750 ret = errno ? -errno : -EIO;
751 goto out_delete_staging_file;
752 }
753
754 /* Create a blob descriptor for the staging file. */
755 new_blob = new_blob_descriptor();
756 if (unlikely(!new_blob)) {
757 ret = -ENOMEM;
758 goto out_delete_staging_file;
759 }
760
761 /* There may already be open file descriptors to this stream if it's
762 * previously been opened read-only, but just now we're opening it
763 * read-write. Identify those file descriptors, update them to use the
764 * new blob descriptor, and open staging file descriptors for them. */
765 for (u16 i = 0, j = 0; j < inode->i_num_opened_fds; i++) {
766 struct wimfs_fd *fd;
767 int raw_fd;
768
769 fd = inode->i_fds[i];
770 if (!fd)
771 continue;
772
773 j++;
774
775 if (fd->f_stream_id != strm->stream_id)
776 continue;
777
778 /* This is a readonly fd for the same stream. */
779 fd->f_blob = new_blob;
780 new_blob->num_opened_fds++;
781 raw_fd = openat(ctx->staging_dir_fd, staging_file_name,
782 O_RDONLY | O_NOFOLLOW);
783 if (unlikely(raw_fd < 0)) {
784 ret = -errno;
785 goto out_revert_fd_changes;
786 }
787 filedes_init(&fd->f_staging_fd, raw_fd);
788 }
789
790 if (old_blob)
791 old_blob->num_opened_fds -= new_blob->num_opened_fds;
792
793 new_blob->blob_location = BLOB_IN_STAGING_FILE;
794 new_blob->staging_file_name = staging_file_name;
795 new_blob->staging_dir_fd = ctx->staging_dir_fd;
796 new_blob->size = size;
797
798 prepare_unhashed_blob(new_blob, inode, strm->stream_id,
799 &wim_get_current_image_metadata(ctx->wim)->unhashed_blobs);
800 inode_replace_stream_blob(inode, strm, new_blob, ctx->wim->blob_table);
801 return 0;
802
803 out_revert_fd_changes:
804 for (u16 i = 0; new_blob->num_opened_fds; i++) {
805 struct wimfs_fd *fd = inode->i_fds[i];
806 if (fd && fd->f_stream_id == strm->stream_id) {
807 fd->f_blob = old_blob;
808 if (filedes_valid(&fd->f_staging_fd)) {
809 filedes_close(&fd->f_staging_fd);
810 filedes_invalidate(&fd->f_staging_fd);
811 }
812 new_blob->num_opened_fds--;
813 }
814 }
815 free_blob_descriptor(new_blob);
816 out_delete_staging_file:
817 unlinkat(ctx->staging_dir_fd, staging_file_name, 0);
818 FREE(staging_file_name);
819 return ret;
820 }
821
822 /*
823 * Create the staging directory for the WIM file.
824 *
825 * The staging directory will be created in the directory specified by the open
826 * file descriptor @parent_dir_fd. It will be given a randomly generated name
827 * based on @wim_basename, the name of the WIM file.
828 *
829 * On success, returns a file descriptor to the open staging directory with
830 * O_RDONLY access. In addition, stores the allocated name of the staging
831 * directory (relative to @parent_dir_fd) in @staging_dir_name_ret.
832 * On failure, returns -1 and sets errno.
833 */
834 static int
make_staging_dir_at(int parent_dir_fd,const char * wim_basename,char ** staging_dir_name_ret)835 make_staging_dir_at(int parent_dir_fd, const char *wim_basename,
836 char **staging_dir_name_ret)
837 {
838 static const char common_suffix[8] = ".staging";
839 static const size_t random_suffix_len = 10;
840 size_t wim_basename_len;
841 size_t staging_dir_name_len;
842 char *staging_dir_name;
843 char *p;
844 int fd;
845
846 wim_basename_len = strlen(wim_basename);
847 staging_dir_name_len = wim_basename_len + sizeof(common_suffix) +
848 random_suffix_len;
849 staging_dir_name = MALLOC(staging_dir_name_len + 1);
850 if (!staging_dir_name)
851 return -1;
852
853 p = staging_dir_name;
854 p = mempcpy(p, wim_basename, wim_basename_len);
855 p = mempcpy(p, common_suffix, sizeof(common_suffix));
856 get_random_alnum_chars(p, random_suffix_len);
857 p += random_suffix_len;
858 *p = '\0';
859
860 if (mkdirat(parent_dir_fd, staging_dir_name, 0700))
861 goto err1;
862
863 fd = openat(parent_dir_fd, staging_dir_name,
864 O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
865 if (fd < 0)
866 goto err2;
867
868 *staging_dir_name_ret = staging_dir_name;
869 return fd;
870
871 err2:
872 unlinkat(parent_dir_fd, staging_dir_name, AT_REMOVEDIR);
873 err1:
874 FREE(staging_dir_name);
875 return -1;
876 }
877
878 /*
879 * Create the staging directory and set ctx->staging_dir_fd,
880 * ctx->staging_dir_name, and ctx->parent_dir_fd.
881 */
882 static int
make_staging_dir(struct wimfs_context * ctx,const char * parent_dir_path)883 make_staging_dir(struct wimfs_context *ctx, const char *parent_dir_path)
884 {
885 const char *wim_basename;
886 char *end = NULL;
887 int ret;
888
889 wim_basename = path_basename(ctx->wim->filename);
890
891 if (!parent_dir_path) {
892 /* The user did not specify a directory. Default to creating
893 * the staging directory alongside the WIM file. */
894 if (wim_basename > ctx->wim->filename) {
895 parent_dir_path = ctx->wim->filename;
896 end = (char *)(wim_basename - 1);
897 /* *end must be a slash. Temporarily overwrite it so we
898 * can open the parent directory. */
899 *end = '\0';
900 } else {
901 parent_dir_path = ".";
902 }
903 }
904
905 /* Open the parent directory (in which we'll create our staging
906 * directory). */
907 ctx->parent_dir_fd = open(parent_dir_path, O_RDONLY | O_DIRECTORY);
908 if (ctx->parent_dir_fd < 0) {
909 ERROR_WITH_ERRNO("Can't open directory \"%s\"",
910 parent_dir_path);
911 ret = WIMLIB_ERR_OPENDIR;
912 goto out_restore_wim_filename;
913 }
914
915 ctx->staging_dir_fd = make_staging_dir_at(ctx->parent_dir_fd,
916 wim_basename,
917 &ctx->staging_dir_name);
918 if (ctx->staging_dir_fd < 0) {
919 ERROR_WITH_ERRNO("Can't create staging directory in \"%s\"",
920 parent_dir_path);
921 close(ctx->parent_dir_fd);
922 ret = WIMLIB_ERR_MKDIR;
923 goto out_restore_wim_filename;
924 }
925 ret = 0;
926 out_restore_wim_filename:
927 if (end)
928 *end = '/';
929 return ret;
930 }
931
932 /* Deletes the staging directory, undoing the effects of a successful call to
933 * make_staging_dir(). */
934 static void
delete_staging_dir(struct wimfs_context * ctx)935 delete_staging_dir(struct wimfs_context *ctx)
936 {
937 DIR *dir;
938 struct dirent *ent;
939
940 dir = fdopendir(ctx->staging_dir_fd);
941 if (dir) {
942 while ((ent = readdir(dir)))
943 unlinkat(ctx->staging_dir_fd, ent->d_name, 0);
944 closedir(dir);
945 } else {
946 close(ctx->staging_dir_fd);
947 }
948 if (unlinkat(ctx->parent_dir_fd, ctx->staging_dir_name, AT_REMOVEDIR))
949 WARNING_WITH_ERRNO("Could not delete staging directory");
950 FREE(ctx->staging_dir_name);
951 close(ctx->parent_dir_fd);
952 }
953
954 static void
prepare_inodes(struct wimfs_context * ctx)955 prepare_inodes(struct wimfs_context *ctx)
956 {
957 struct wim_image_metadata *imd;
958 struct wim_inode *inode;
959
960 ctx->next_ino = 1;
961 imd = wim_get_current_image_metadata(ctx->wim);
962 image_for_each_inode(inode, imd) {
963 inode->i_ino = ctx->next_ino++;
964 inode->i_num_opened_fds = 0;
965 inode->i_num_allocated_fds = 0;
966 inode->i_fds = NULL;
967 }
968 }
969
970 /* Delete the 'struct blob_descriptor' for any stream that was modified
971 * or created in the read-write mounted image and had a final size of 0. */
972 static void
delete_empty_blobs(struct wimfs_context * ctx)973 delete_empty_blobs(struct wimfs_context *ctx)
974 {
975 struct blob_descriptor *blob, *tmp;
976 struct wim_image_metadata *imd;
977
978 imd = wim_get_current_image_metadata(ctx->wim);
979
980 image_for_each_unhashed_blob_safe(blob, tmp, imd) {
981 if (!blob->size) {
982 *retrieve_pointer_to_unhashed_blob(blob) = NULL;
983 list_del(&blob->unhashed_list);
984 free_blob_descriptor(blob);
985 }
986 }
987 }
988
989 /* Close all file descriptors open to the specified inode.
990 *
991 * Note: closing the last file descriptor might free the inode. */
992 static void
inode_close_fds(struct wim_inode * inode)993 inode_close_fds(struct wim_inode *inode)
994 {
995 u16 num_open_fds = inode->i_num_opened_fds;
996 for (u16 i = 0; num_open_fds; i++) {
997 if (inode->i_fds[i]) {
998 close_wimfs_fd(inode->i_fds[i]);
999 num_open_fds--;
1000 }
1001 }
1002 }
1003
1004 /* Close all file descriptors open to the mounted image. */
1005 static void
close_all_fds(struct wimfs_context * ctx)1006 close_all_fds(struct wimfs_context *ctx)
1007 {
1008 struct wim_inode *inode;
1009 struct hlist_node *tmp;
1010 struct wim_image_metadata *imd;
1011
1012 imd = wim_get_current_image_metadata(ctx->wim);
1013
1014 image_for_each_inode_safe(inode, tmp, imd)
1015 inode_close_fds(inode);
1016 }
1017
1018 /* Moves the currently selected image, which may have been modified, to a new
1019 * index, and sets the original index to refer to a reset (unmodified) copy of
1020 * the image. */
1021 static int
renew_current_image(struct wimfs_context * ctx)1022 renew_current_image(struct wimfs_context *ctx)
1023 {
1024 WIMStruct *wim = ctx->wim;
1025 int image = wim->current_image;
1026 struct wim_image_metadata *imd;
1027 struct wim_inode *inode;
1028 int ret;
1029
1030 ret = WIMLIB_ERR_NOMEM;
1031 imd = new_unloaded_image_metadata(ctx->metadata_resource);
1032 if (!imd)
1033 goto err;
1034
1035 ret = append_image_metadata(wim, wim->image_metadata[image - 1]);
1036 if (ret)
1037 goto err_put_imd;
1038
1039 ret = xml_export_image(wim->xml_info, image,
1040 wim->xml_info, NULL, NULL, false);
1041 if (ret)
1042 goto err_undo_append;
1043
1044 wim->image_metadata[image - 1] = imd;
1045 wim->current_image = wim->hdr.image_count;
1046
1047 ret = select_wim_image(wim, image);
1048 if (ret)
1049 goto err_undo_export;
1050
1051 image_for_each_inode(inode, imd) {
1052 for (unsigned i = 0; i < inode->i_num_streams; i++) {
1053 struct blob_descriptor *blob;
1054
1055 blob = stream_blob(&inode->i_streams[i],
1056 wim->blob_table);
1057 if (blob)
1058 blob->refcnt += inode->i_nlink;
1059 }
1060 }
1061
1062 select_wim_image(wim, wim->hdr.image_count);
1063 ctx->metadata_resource = NULL;
1064 return 0;
1065
1066 err_undo_export:
1067 xml_delete_image(wim->xml_info, wim->hdr.image_count);
1068 wim->image_metadata[image - 1] = wim->image_metadata[wim->hdr.image_count - 1];
1069 wim->current_image = image;
1070 err_undo_append:
1071 wim->hdr.image_count--;
1072 err_put_imd:
1073 imd->metadata_blob = NULL;
1074 put_image_metadata(imd);
1075 err:
1076 return ret;
1077 }
1078
1079 static enum wimlib_progress_status
commit_progress_func(enum wimlib_progress_msg msg,union wimlib_progress_info * info,void * progctx)1080 commit_progress_func(enum wimlib_progress_msg msg,
1081 union wimlib_progress_info *info, void *progctx)
1082 {
1083 mqd_t mq = *(mqd_t *)progctx;
1084 struct commit_progress_report report;
1085
1086 memset(&report, 0, sizeof(report));
1087 report.msg = msg;
1088 if (info)
1089 report.info = *info;
1090 mq_send(mq, (const char *)&report, sizeof(report), 1);
1091 return WIMLIB_PROGRESS_STATUS_CONTINUE;
1092 }
1093
1094 /* Commit the mounted image to the underlying WIM file. */
1095 static int
commit_image(struct wimfs_context * ctx,int unmount_flags,mqd_t mq)1096 commit_image(struct wimfs_context *ctx, int unmount_flags, mqd_t mq)
1097 {
1098 int write_flags;
1099
1100 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_SEND_PROGRESS)
1101 wimlib_register_progress_function(ctx->wim,
1102 commit_progress_func, &mq);
1103 else
1104 wimlib_register_progress_function(ctx->wim, NULL, NULL);
1105
1106 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_NEW_IMAGE) {
1107 int ret = renew_current_image(ctx);
1108 if (ret)
1109 return ret;
1110 }
1111 delete_empty_blobs(ctx);
1112
1113 write_flags = 0;
1114
1115 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY)
1116 write_flags |= WIMLIB_WRITE_FLAG_CHECK_INTEGRITY;
1117
1118 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_REBUILD)
1119 write_flags |= WIMLIB_WRITE_FLAG_REBUILD;
1120
1121 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_RECOMPRESS)
1122 write_flags |= WIMLIB_WRITE_FLAG_RECOMPRESS;
1123
1124 return wimlib_overwrite(ctx->wim, write_flags, 0);
1125 }
1126
1127 /* In the case of an allow_other mount, only the mount owner and root are
1128 * allowed to unmount the filesystem. */
1129 static bool
may_unmount_wimfs(void)1130 may_unmount_wimfs(void)
1131 {
1132 const struct fuse_context *fuse_ctx = fuse_get_context();
1133 const struct wimfs_context *wimfs_ctx = WIMFS_CTX(fuse_ctx);
1134
1135 return (fuse_ctx->uid == wimfs_ctx->owner_uid ||
1136 fuse_ctx->uid == 0);
1137 }
1138
1139 /* Unmount the mounted image, called from the daemon process. */
1140 static int
unmount_wimfs(void)1141 unmount_wimfs(void)
1142 {
1143 struct fuse_context *fuse_ctx = fuse_get_context();
1144 struct wimfs_context *wimfs_ctx = WIMFS_CTX(fuse_ctx);
1145 const struct wimfs_unmount_info *info = &wimfs_ctx->unmount_info;
1146 int unmount_flags = info->unmount_flags;
1147 mqd_t mq = (mqd_t)-1;
1148 int ret;
1149
1150 /* Ignore COMMIT if the image is mounted read-only. */
1151 if (!(wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE))
1152 unmount_flags &= ~WIMLIB_UNMOUNT_FLAG_COMMIT;
1153
1154 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_SEND_PROGRESS) {
1155 mq = mq_open(info->mq_name, O_WRONLY | O_NONBLOCK);
1156 if (mq == (mqd_t)-1) {
1157 ret = WIMLIB_ERR_MQUEUE;
1158 goto out;
1159 }
1160 }
1161
1162 if (wimfs_ctx->num_open_fds) {
1163
1164 /* There are still open file descriptors to the image. */
1165
1166 /* With COMMIT, refuse to unmount unless FORCE is also
1167 * specified. */
1168 if ((unmount_flags & (WIMLIB_UNMOUNT_FLAG_COMMIT |
1169 WIMLIB_UNMOUNT_FLAG_FORCE))
1170 == WIMLIB_UNMOUNT_FLAG_COMMIT)
1171 {
1172 ret = WIMLIB_ERR_MOUNTED_IMAGE_IS_BUSY;
1173 goto out;
1174 }
1175
1176 /* Force-close all file descriptors. */
1177 close_all_fds(wimfs_ctx);
1178 }
1179
1180 if (unmount_flags & WIMLIB_UNMOUNT_FLAG_COMMIT)
1181 ret = commit_image(wimfs_ctx, unmount_flags, mq);
1182 else
1183 ret = 0; /* Read-only mount, or discarding changes to
1184 a read-write mount */
1185
1186 out:
1187 /* Leave the image mounted if commit failed, unless this is a
1188 * forced unmount. The user can retry without COMMIT if they
1189 * want. */
1190 if (!ret || (unmount_flags & WIMLIB_UNMOUNT_FLAG_FORCE)) {
1191 unlock_wim_for_append(wimfs_ctx->wim);
1192 fuse_exit(fuse_ctx->fuse);
1193 }
1194 if (mq != (mqd_t)-1)
1195 mq_close(mq);
1196 return ret;
1197 }
1198
1199 static int
wimfs_chmod(const char * path,mode_t mask)1200 wimfs_chmod(const char *path, mode_t mask)
1201 {
1202 const struct wimfs_context *ctx = wimfs_get_context();
1203 struct wim_inode *inode;
1204 struct wimlib_unix_data unix_data;
1205
1206 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_UNIX_DATA))
1207 return -EOPNOTSUPP;
1208
1209 inode = wim_pathname_to_inode(ctx->wim, path);
1210 if (!inode)
1211 return -errno;
1212
1213 unix_data.uid = ctx->owner_uid;
1214 unix_data.gid = ctx->owner_gid;
1215 unix_data.mode = mask;
1216 unix_data.rdev = 0;
1217
1218 if (!inode_set_unix_data(inode, &unix_data, UNIX_DATA_MODE))
1219 return -ENOMEM;
1220
1221 return 0;
1222 }
1223
1224 static int
wimfs_chown(const char * path,uid_t uid,gid_t gid)1225 wimfs_chown(const char *path, uid_t uid, gid_t gid)
1226 {
1227 const struct wimfs_context *ctx = wimfs_get_context();
1228 struct wim_inode *inode;
1229 struct wimlib_unix_data unix_data;
1230 int which;
1231
1232 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_UNIX_DATA))
1233 return -EOPNOTSUPP;
1234
1235 inode = wim_pathname_to_inode(ctx->wim, path);
1236 if (!inode)
1237 return -errno;
1238
1239 which = 0;
1240
1241 if (uid != (uid_t)-1)
1242 which |= UNIX_DATA_UID;
1243 else
1244 uid = ctx->owner_uid;
1245
1246 if (gid != (gid_t)-1)
1247 which |= UNIX_DATA_GID;
1248 else
1249 gid = ctx->owner_gid;
1250
1251 unix_data.uid = uid;
1252 unix_data.gid = gid;
1253 unix_data.mode = inode_default_unix_mode(inode);
1254 unix_data.rdev = 0;
1255
1256 if (!inode_set_unix_data(inode, &unix_data, which))
1257 return -ENOMEM;
1258
1259 return 0;
1260 }
1261
1262 static int
wimfs_fgetattr(const char * path,struct stat * stbuf,struct fuse_file_info * fi)1263 wimfs_fgetattr(const char *path, struct stat *stbuf, struct fuse_file_info *fi)
1264 {
1265 struct wimfs_fd *fd = WIMFS_FD(fi);
1266 return inode_to_stbuf(fd->f_inode, fd->f_blob, stbuf);
1267 }
1268
1269 static int
wimfs_ftruncate(const char * path,off_t size,struct fuse_file_info * fi)1270 wimfs_ftruncate(const char *path, off_t size, struct fuse_file_info *fi)
1271 {
1272 struct wimfs_fd *fd = WIMFS_FD(fi);
1273 if (ftruncate(fd->f_staging_fd.fd, size))
1274 return -errno;
1275 touch_inode(fd->f_inode);
1276 fd->f_blob->size = size;
1277 return 0;
1278 }
1279
1280 static int
wimfs_getattr(const char * path,struct stat * stbuf)1281 wimfs_getattr(const char *path, struct stat *stbuf)
1282 {
1283 const struct wimfs_context *ctx = wimfs_get_context();
1284 struct wim_dentry *dentry;
1285 struct wim_inode_stream *strm;
1286 int ret;
1287
1288 ret = wim_pathname_to_stream(ctx, path, LOOKUP_FLAG_DIRECTORY_OK,
1289 &dentry, &strm);
1290 if (ret)
1291 return ret;
1292
1293 return inode_to_stbuf(dentry->d_inode,
1294 stream_blob_resolved(strm), stbuf);
1295 }
1296
1297 static int
copy_xattr(char * dest,size_t destsize,const void * src,size_t srcsize)1298 copy_xattr(char *dest, size_t destsize, const void *src, size_t srcsize)
1299 {
1300 if (destsize) {
1301 if (destsize < srcsize)
1302 return -ERANGE;
1303 memcpy(dest, src, srcsize);
1304 }
1305 return srcsize;
1306 }
1307
1308 static int
wimfs_getxattr(const char * path,const char * name,char * value,size_t size)1309 wimfs_getxattr(const char *path, const char *name, char *value,
1310 size_t size)
1311 {
1312 const struct wimfs_context *ctx = wimfs_get_context();
1313 const struct wim_inode *inode;
1314 const struct wim_inode_stream *strm;
1315 const struct blob_descriptor *blob;
1316
1317 if (!strncmp(name, "wimfs.", 6)) {
1318 /* Handle some magical extended attributes. These really should
1319 * be ioctls, but directory ioctls aren't supported until
1320 * libfuse 2.9, and even then they are broken. */
1321 name += 6;
1322 if (!strcmp(name, "wim_filename")) {
1323 return copy_xattr(value, size, ctx->wim->filename,
1324 strlen(ctx->wim->filename));
1325 }
1326 if (!strcmp(name, "wim_info")) {
1327 struct wimlib_wim_info info;
1328
1329 wimlib_get_wim_info(ctx->wim, &info);
1330
1331 return copy_xattr(value, size, &info, sizeof(info));
1332 }
1333 if (!strcmp(name, "mounted_image")) {
1334 return copy_xattr(value, size,
1335 &ctx->wim->current_image, sizeof(int));
1336 }
1337 if (!strcmp(name, "mount_flags")) {
1338 return copy_xattr(value, size,
1339 &ctx->mount_flags, sizeof(int));
1340 }
1341 if (!strcmp(name, "unmount")) {
1342 if (!may_unmount_wimfs())
1343 return -EPERM;
1344 if (size) {
1345 int status;
1346
1347 if (size < sizeof(int))
1348 return -ERANGE;
1349 status = unmount_wimfs();
1350 memcpy(value, &status, sizeof(int));
1351 }
1352 return sizeof(int);
1353 }
1354 return -ENOATTR;
1355 }
1356
1357 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1358 return -ENOTSUP;
1359
1360 if (strncmp(name, "user.", 5))
1361 return -ENOATTR;
1362 name += 5;
1363
1364 if (!*name)
1365 return -ENOATTR;
1366
1367 /* Querying a named data stream */
1368
1369 inode = wim_pathname_to_inode(ctx->wim, path);
1370 if (!inode)
1371 return -errno;
1372
1373 strm = inode_get_data_stream_tstr(inode, name);
1374 if (!strm)
1375 return (errno == ENOENT) ? -ENOATTR : -errno;
1376
1377 blob = stream_blob_resolved(strm);
1378 if (!blob)
1379 return 0;
1380
1381 if (unlikely(blob->size > INT_MAX))
1382 return -EFBIG;
1383
1384 if (size) {
1385 if (size < blob->size)
1386 return -ERANGE;
1387
1388 if (read_blob_into_buf(blob, value))
1389 return errno ? -errno : -EIO;
1390 }
1391 return blob->size;
1392 }
1393
1394 static int
wimfs_link(const char * existing_path,const char * new_path)1395 wimfs_link(const char *existing_path, const char *new_path)
1396 {
1397 WIMStruct *wim = wimfs_get_WIMStruct();
1398 const char *new_name;
1399 struct wim_inode *inode;
1400 struct wim_dentry *dir;
1401 struct wim_dentry *new_alias;
1402
1403 inode = wim_pathname_to_inode(wim, existing_path);
1404 if (!inode)
1405 return -errno;
1406
1407 if (inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
1408 FILE_ATTRIBUTE_REPARSE_POINT))
1409 return -EPERM;
1410
1411 new_name = path_basename(new_path);
1412
1413 dir = get_parent_dentry(wim, new_path, WIMLIB_CASE_SENSITIVE);
1414 if (!dir)
1415 return -errno;
1416
1417 if (!dentry_is_directory(dir))
1418 return -ENOTDIR;
1419
1420 if (get_dentry_child_with_name(dir, new_name, WIMLIB_CASE_SENSITIVE))
1421 return -EEXIST;
1422
1423 if (new_dentry_with_existing_inode(new_name, inode, &new_alias))
1424 return -ENOMEM;
1425
1426 dentry_add_child(dir, new_alias);
1427 touch_inode(dir->d_inode);
1428 return 0;
1429 }
1430
1431 static int
wimfs_listxattr(const char * path,char * list,size_t size)1432 wimfs_listxattr(const char *path, char *list, size_t size)
1433 {
1434 const struct wimfs_context *ctx = wimfs_get_context();
1435 const struct wim_inode *inode;
1436 char *p = list;
1437 char *end = list + size;
1438 int total_size = 0;
1439
1440 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1441 return -ENOTSUP;
1442
1443 /* List named data streams, or get the list size. We report each named
1444 * data stream "X" as an extended attribute "user.X". */
1445
1446 inode = wim_pathname_to_inode(ctx->wim, path);
1447 if (!inode)
1448 return -errno;
1449
1450 for (unsigned i = 0; i < inode->i_num_streams; i++) {
1451 const struct wim_inode_stream *strm;
1452 char *stream_name_mbs;
1453 size_t stream_name_mbs_nbytes;
1454
1455 strm = &inode->i_streams[i];
1456
1457 if (!stream_is_named_data_stream(strm))
1458 continue;
1459
1460 if (utf16le_to_tstr(strm->stream_name,
1461 utf16le_len_bytes(strm->stream_name),
1462 &stream_name_mbs,
1463 &stream_name_mbs_nbytes))
1464 return -errno;
1465
1466 if (unlikely(INT_MAX - total_size < stream_name_mbs_nbytes + 6)) {
1467 FREE(stream_name_mbs);
1468 return -EFBIG;
1469 }
1470
1471 total_size += stream_name_mbs_nbytes + 6;
1472 if (size) {
1473 if (end - p < stream_name_mbs_nbytes + 6) {
1474 FREE(stream_name_mbs);
1475 return -ERANGE;
1476 }
1477 p = mempcpy(p, "user.", 5);
1478 p = mempcpy(p, stream_name_mbs, stream_name_mbs_nbytes);
1479 *p++ = '\0';
1480 }
1481 FREE(stream_name_mbs);
1482 }
1483 return total_size;
1484 }
1485
1486 static int
wimfs_mkdir(const char * path,mode_t mode)1487 wimfs_mkdir(const char *path, mode_t mode)
1488 {
1489 struct wim_dentry *dentry;
1490 int ret;
1491
1492 /* Note: according to fuse.h, mode may not include S_IFDIR */
1493 ret = create_file(fuse_get_context(), path, mode | S_IFDIR, 0, &dentry);
1494 if (ret)
1495 return ret;
1496 touch_parent(dentry);
1497 return 0;
1498 }
1499
1500 static int
wimfs_mknod(const char * path,mode_t mode,dev_t rdev)1501 wimfs_mknod(const char *path, mode_t mode, dev_t rdev)
1502 {
1503 struct fuse_context *fuse_ctx = fuse_get_context();
1504 struct wimfs_context *wimfs_ctx = WIMFS_CTX(fuse_ctx);
1505 const char *stream_name;
1506
1507 if ((wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
1508 && (stream_name = path_stream_name(path)))
1509 {
1510 struct wim_inode *inode;
1511 struct wim_inode_stream *existing_strm;
1512 struct wim_inode_stream *new_strm;
1513 char *p;
1514 const utf16lechar *uname;
1515
1516 /* Create a named data stream. */
1517
1518 if (!S_ISREG(mode))
1519 return -EOPNOTSUPP;
1520
1521 p = (char *)stream_name - 1;
1522
1523 *p = '\0';
1524 inode = wim_pathname_to_inode(wimfs_ctx->wim, path);
1525 *p = ':';
1526 if (!inode)
1527 return -errno;
1528
1529 if (tstr_get_utf16le(stream_name, &uname))
1530 return -errno;
1531
1532 existing_strm = inode_get_stream(inode, STREAM_TYPE_DATA, uname);
1533 if (existing_strm) {
1534 tstr_put_utf16le(uname);
1535 return -EEXIST;
1536 }
1537
1538 new_strm = inode_add_stream(inode, STREAM_TYPE_DATA, uname, NULL);
1539
1540 tstr_put_utf16le(uname);
1541
1542 if (!new_strm)
1543 return -errno;
1544 return 0;
1545 } else {
1546 /* Create a regular file, device node, named pipe, or socket.
1547 */
1548 struct wim_dentry *dentry;
1549 int ret;
1550
1551 if (!S_ISREG(mode) &&
1552 !(wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_UNIX_DATA))
1553 return -EPERM;
1554
1555 ret = create_file(fuse_ctx, path, mode, rdev, &dentry);
1556 if (ret)
1557 return ret;
1558 touch_parent(dentry);
1559 return 0;
1560 }
1561 }
1562
1563 static int
wimfs_open(const char * path,struct fuse_file_info * fi)1564 wimfs_open(const char *path, struct fuse_file_info *fi)
1565 {
1566 struct wimfs_context *ctx = wimfs_get_context();
1567 struct wim_dentry *dentry;
1568 struct wim_inode *inode;
1569 struct wim_inode_stream *strm;
1570 struct blob_descriptor *blob;
1571 struct wimfs_fd *fd;
1572 int ret;
1573
1574 ret = wim_pathname_to_stream(ctx, path, 0, &dentry, &strm);
1575 if (ret)
1576 return ret;
1577
1578 inode = dentry->d_inode;
1579 blob = stream_blob_resolved(strm);
1580
1581 /* The data of the file being opened may be in the staging directory
1582 * (read-write mounts only) or in the WIM. If it's in the staging
1583 * directory, we need to open a native file descriptor for the
1584 * corresponding file. Otherwise, we can read the file data directly
1585 * from the WIM file if we are opening it read-only, but we need to
1586 * extract the data to the staging directory if we are opening it
1587 * writable. */
1588
1589 if (flags_writable(fi->flags) &&
1590 (!blob || blob->blob_location != BLOB_IN_STAGING_FILE)) {
1591 ret = extract_blob_to_staging_dir(inode,
1592 strm,
1593 blob_size(blob),
1594 ctx);
1595 if (ret)
1596 return ret;
1597 blob = stream_blob_resolved(strm);
1598 }
1599
1600 ret = alloc_wimfs_fd(inode, strm, &fd);
1601 if (ret)
1602 return ret;
1603
1604 if (blob && blob->blob_location == BLOB_IN_STAGING_FILE) {
1605 int raw_fd;
1606
1607 raw_fd = openat(blob->staging_dir_fd, blob->staging_file_name,
1608 (fi->flags & O_ACCMODE) | O_NOFOLLOW);
1609 if (raw_fd < 0) {
1610 close_wimfs_fd(fd);
1611 return -errno;
1612 }
1613 filedes_init(&fd->f_staging_fd, raw_fd);
1614 }
1615 fi->fh = (uintptr_t)fd;
1616 return 0;
1617 }
1618
1619 static int
wimfs_opendir(const char * path,struct fuse_file_info * fi)1620 wimfs_opendir(const char *path, struct fuse_file_info *fi)
1621 {
1622 WIMStruct *wim = wimfs_get_WIMStruct();
1623 struct wim_inode *inode;
1624 struct wim_inode_stream *strm;
1625 struct wimfs_fd *fd;
1626 int ret;
1627
1628 inode = wim_pathname_to_inode(wim, path);
1629 if (!inode)
1630 return -errno;
1631 if (!inode_is_directory(inode))
1632 return -ENOTDIR;
1633 strm = inode_get_unnamed_data_stream(inode);
1634 if (!strm)
1635 return -ENOTDIR;
1636 ret = alloc_wimfs_fd(inode, strm, &fd);
1637 if (ret)
1638 return ret;
1639 fi->fh = (uintptr_t)fd;
1640 return 0;
1641 }
1642
1643 static int
wimfs_read(const char * path,char * buf,size_t size,off_t offset,struct fuse_file_info * fi)1644 wimfs_read(const char *path, char *buf, size_t size,
1645 off_t offset, struct fuse_file_info *fi)
1646 {
1647 struct wimfs_fd *fd = WIMFS_FD(fi);
1648 const struct blob_descriptor *blob;
1649 ssize_t ret;
1650
1651 blob = fd->f_blob;
1652 if (!blob)
1653 return 0;
1654
1655 if (offset >= blob->size)
1656 return 0;
1657
1658 if (size > blob->size - offset)
1659 size = blob->size - offset;
1660
1661 if (!size)
1662 return 0;
1663
1664 switch (blob->blob_location) {
1665 case BLOB_IN_WIM:
1666 if (read_partial_wim_blob_into_buf(blob, offset, size, buf))
1667 ret = errno ? -errno : -EIO;
1668 else
1669 ret = size;
1670 break;
1671 case BLOB_IN_STAGING_FILE:
1672 ret = pread(fd->f_staging_fd.fd, buf, size, offset);
1673 if (ret < 0)
1674 ret = -errno;
1675 break;
1676 case BLOB_IN_ATTACHED_BUFFER:
1677 memcpy(buf, blob->attached_buffer + offset, size);
1678 ret = size;
1679 break;
1680 default:
1681 ret = -EINVAL;
1682 break;
1683 }
1684 return ret;
1685 }
1686
1687 static int
wimfs_readdir(const char * path,void * buf,fuse_fill_dir_t filler,off_t offset,struct fuse_file_info * fi)1688 wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
1689 off_t offset, struct fuse_file_info *fi)
1690 {
1691 struct wimfs_fd *fd = WIMFS_FD(fi);
1692 const struct wim_inode *inode;
1693 const struct wim_dentry *child;
1694 int ret;
1695
1696 inode = fd->f_inode;
1697
1698 ret = filler(buf, ".", NULL, 0);
1699 if (ret)
1700 return ret;
1701 ret = filler(buf, "..", NULL, 0);
1702 if (ret)
1703 return ret;
1704
1705 for_inode_child(child, inode) {
1706 char *name;
1707 size_t name_nbytes;
1708
1709 if (utf16le_to_tstr(child->d_name, child->d_name_nbytes,
1710 &name, &name_nbytes))
1711 return -errno;
1712
1713 ret = filler(buf, name, NULL, 0);
1714 FREE(name);
1715 if (ret)
1716 return ret;
1717 }
1718 return 0;
1719 }
1720
1721 static int
wimfs_readlink(const char * path,char * buf,size_t bufsize)1722 wimfs_readlink(const char *path, char *buf, size_t bufsize)
1723 {
1724 struct wimfs_context *ctx = wimfs_get_context();
1725 const struct wim_inode *inode;
1726 int ret;
1727
1728 inode = wim_pathname_to_inode(ctx->wim, path);
1729 if (!inode)
1730 return -errno;
1731 if (bufsize <= 0)
1732 return -EINVAL;
1733 ret = wim_inode_readlink(inode, buf, bufsize - 1, NULL,
1734 ctx->mountpoint_abspath,
1735 ctx->mountpoint_abspath_nchars);
1736 if (ret < 0)
1737 return ret;
1738 buf[ret] = '\0';
1739 return 0;
1740 }
1741
1742 /* We use this for both release() and releasedir(), since in both cases we
1743 * simply need to close the file descriptor. */
1744 static int
wimfs_release(const char * path,struct fuse_file_info * fi)1745 wimfs_release(const char *path, struct fuse_file_info *fi)
1746 {
1747 return close_wimfs_fd(WIMFS_FD(fi));
1748 }
1749
1750 static int
wimfs_removexattr(const char * path,const char * name)1751 wimfs_removexattr(const char *path, const char *name)
1752 {
1753 struct wimfs_context *ctx = wimfs_get_context();
1754 struct wim_inode *inode;
1755 struct wim_inode_stream *strm;
1756
1757 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1758 return -ENOTSUP;
1759
1760 if (strncmp(name, "user.", 5))
1761 return -ENOATTR;
1762 name += 5;
1763
1764 if (!*name)
1765 return -ENOATTR;
1766
1767 /* Removing a named data stream. */
1768
1769 inode = wim_pathname_to_inode(ctx->wim, path);
1770 if (!inode)
1771 return -errno;
1772
1773 strm = inode_get_data_stream_tstr(inode, name);
1774 if (!strm)
1775 return (errno == ENOENT) ? -ENOATTR : -errno;
1776
1777 inode_remove_stream(inode, strm, ctx->wim->blob_table);
1778 return 0;
1779 }
1780
1781 static int
wimfs_rename(const char * from,const char * to)1782 wimfs_rename(const char *from, const char *to)
1783 {
1784 return rename_wim_path(wimfs_get_WIMStruct(), from, to,
1785 WIMLIB_CASE_SENSITIVE, NULL);
1786 }
1787
1788 static int
wimfs_rmdir(const char * path)1789 wimfs_rmdir(const char *path)
1790 {
1791 WIMStruct *wim = wimfs_get_WIMStruct();
1792 struct wim_dentry *dentry;
1793
1794 dentry = get_dentry(wim, path, WIMLIB_CASE_SENSITIVE);
1795 if (!dentry)
1796 return -errno;
1797
1798 if (!dentry_is_directory(dentry))
1799 return -ENOTDIR;
1800
1801 if (dentry_has_children(dentry))
1802 return -ENOTEMPTY;
1803
1804 touch_parent(dentry);
1805 remove_dentry(dentry, wim->blob_table);
1806 return 0;
1807 }
1808
1809 static int
wimfs_setxattr(const char * path,const char * name,const char * value,size_t size,int flags)1810 wimfs_setxattr(const char *path, const char *name,
1811 const char *value, size_t size, int flags)
1812 {
1813 struct wimfs_context *ctx = wimfs_get_context();
1814 struct wim_inode *inode;
1815 struct wim_inode_stream *strm;
1816 const utf16lechar *uname;
1817 int ret;
1818
1819 if (!strncmp(name, "wimfs.", 6)) {
1820 /* Handle some magical extended attributes. These really should
1821 * be ioctls, but directory ioctls aren't supported until
1822 * libfuse 2.9, and even then they are broken. [Fixed by
1823 * libfuse commit e3b7d4c278a26520be63d99d6ea84b26906fe73d] */
1824 name += 6;
1825 if (!strcmp(name, "unmount_info")) {
1826 if (!may_unmount_wimfs())
1827 return -EPERM;
1828 if (size < sizeof(struct wimfs_unmount_info))
1829 return -EINVAL;
1830 memcpy(&ctx->unmount_info, value,
1831 sizeof(struct wimfs_unmount_info));
1832 return 0;
1833 }
1834 return -ENOATTR;
1835 }
1836
1837 if (!(ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
1838 return -ENOTSUP;
1839
1840 if (strncmp(name, "user.", 5))
1841 return -ENOATTR;
1842 name += 5;
1843
1844 if (!*name)
1845 return -ENOATTR;
1846
1847 /* Setting the contents of a named data stream. */
1848
1849 inode = wim_pathname_to_inode(ctx->wim, path);
1850 if (!inode)
1851 return -errno;
1852
1853 ret = tstr_get_utf16le(name, &uname);
1854 if (ret)
1855 return -errno;
1856
1857 strm = inode_get_stream(inode, STREAM_TYPE_DATA, uname);
1858 if (strm) {
1859 ret = -EEXIST;
1860 if (flags & XATTR_CREATE)
1861 goto out_put_uname;
1862 } else {
1863 ret = -ENOATTR;
1864 if (flags & XATTR_REPLACE)
1865 goto out_put_uname;
1866 }
1867
1868 if (strm) {
1869 if (!inode_replace_stream_data(inode, strm, value, size,
1870 ctx->wim->blob_table))
1871 {
1872 ret = -errno;
1873 goto out_put_uname;
1874 }
1875 } else {
1876 if (!inode_add_stream_with_data(inode, STREAM_TYPE_DATA, uname,
1877 value, size, ctx->wim->blob_table))
1878 {
1879 ret = -errno;
1880 goto out_put_uname;
1881 }
1882 }
1883
1884 ret = 0;
1885 out_put_uname:
1886 tstr_put_utf16le(uname);
1887 return ret;
1888 }
1889
1890 static int
wimfs_symlink(const char * to,const char * from)1891 wimfs_symlink(const char *to, const char *from)
1892 {
1893 struct fuse_context *fuse_ctx = fuse_get_context();
1894 struct wimfs_context *wimfs_ctx = WIMFS_CTX(fuse_ctx);
1895 struct wim_dentry *dentry;
1896 int ret;
1897
1898 ret = create_file(fuse_ctx, from, S_IFLNK | 0777, 0, &dentry);
1899 if (ret)
1900 return ret;
1901 ret = wim_inode_set_symlink(dentry->d_inode, to,
1902 wimfs_ctx->wim->blob_table);
1903 if (ret) {
1904 remove_dentry(dentry, wimfs_ctx->wim->blob_table);
1905 if (ret == WIMLIB_ERR_NOMEM)
1906 ret = -ENOMEM;
1907 else
1908 ret = -EINVAL;
1909 } else {
1910 touch_parent(dentry);
1911 }
1912 return ret;
1913 }
1914
1915 static int
wimfs_truncate(const char * path,off_t size)1916 wimfs_truncate(const char *path, off_t size)
1917 {
1918 const struct wimfs_context *ctx = wimfs_get_context();
1919 struct wim_dentry *dentry;
1920 struct wim_inode_stream *strm;
1921 struct blob_descriptor *blob;
1922 int ret;
1923 int fd;
1924
1925 ret = wim_pathname_to_stream(ctx, path, 0, &dentry, &strm);
1926 if (ret)
1927 return ret;
1928
1929 blob = stream_blob_resolved(strm);
1930
1931 if (!blob && !size)
1932 return 0;
1933
1934 if (!blob || blob->blob_location != BLOB_IN_STAGING_FILE) {
1935 return extract_blob_to_staging_dir(dentry->d_inode,
1936 strm, size, ctx);
1937 }
1938
1939 /* Truncate the staging file. */
1940 fd = openat(blob->staging_dir_fd, blob->staging_file_name,
1941 O_WRONLY | O_NOFOLLOW);
1942 if (fd < 0)
1943 return -errno;
1944 ret = ftruncate(fd, size);
1945 if (close(fd) || ret)
1946 return -errno;
1947 blob->size = size;
1948 touch_inode(dentry->d_inode);
1949 return 0;
1950 }
1951
1952 static int
wimfs_unlink(const char * path)1953 wimfs_unlink(const char *path)
1954 {
1955 const struct wimfs_context *ctx = wimfs_get_context();
1956 struct wim_dentry *dentry;
1957 struct wim_inode_stream *strm;
1958 int ret;
1959
1960 ret = wim_pathname_to_stream(ctx, path, 0, &dentry, &strm);
1961 if (ret)
1962 return ret;
1963
1964 if (stream_is_named(strm)) {
1965 inode_remove_stream(dentry->d_inode, strm,
1966 ctx->wim->blob_table);
1967 } else {
1968 touch_parent(dentry);
1969 remove_dentry(dentry, ctx->wim->blob_table);
1970 }
1971 return 0;
1972 }
1973
1974 #ifdef HAVE_UTIMENSAT
1975 /*
1976 * Change the timestamp on a file dentry.
1977 *
1978 * Note that alternate data streams do not have their own timestamps.
1979 */
1980 static int
wimfs_utimens(const char * path,const struct timespec tv[2])1981 wimfs_utimens(const char *path, const struct timespec tv[2])
1982 {
1983 WIMStruct *wim = wimfs_get_WIMStruct();
1984 struct wim_inode *inode;
1985
1986 inode = wim_pathname_to_inode(wim, path);
1987 if (!inode)
1988 return -errno;
1989
1990 if (tv[0].tv_nsec != UTIME_OMIT) {
1991 if (tv[0].tv_nsec == UTIME_NOW)
1992 inode->i_last_access_time = now_as_wim_timestamp();
1993 else
1994 inode->i_last_access_time = timespec_to_wim_timestamp(&tv[0]);
1995 }
1996 if (tv[1].tv_nsec != UTIME_OMIT) {
1997 if (tv[1].tv_nsec == UTIME_NOW)
1998 inode->i_last_write_time = now_as_wim_timestamp();
1999 else
2000 inode->i_last_write_time = timespec_to_wim_timestamp(&tv[1]);
2001 }
2002 return 0;
2003 }
2004 #else /* HAVE_UTIMENSAT */
2005 static int
wimfs_utime(const char * path,struct utimbuf * times)2006 wimfs_utime(const char *path, struct utimbuf *times)
2007 {
2008 WIMStruct *wim = wimfs_get_WIMStruct();
2009 struct wim_inode *inode;
2010
2011 inode = wim_pathname_to_inode(wim, path);
2012 if (!inode)
2013 return -errno;
2014
2015 inode->i_last_access_time = time_t_to_wim_timestamp(times->actime);
2016 inode->i_last_write_time = time_t_to_wim_timestamp(times->modtime);
2017 return 0;
2018 }
2019 #endif /* !HAVE_UTIMENSAT */
2020
2021 static int
wimfs_write(const char * path,const char * buf,size_t size,off_t offset,struct fuse_file_info * fi)2022 wimfs_write(const char *path, const char *buf, size_t size,
2023 off_t offset, struct fuse_file_info *fi)
2024 {
2025 struct wimfs_fd *fd = WIMFS_FD(fi);
2026 ssize_t ret;
2027
2028 ret = pwrite(fd->f_staging_fd.fd, buf, size, offset);
2029 if (ret < 0)
2030 return -errno;
2031
2032 if (offset + size > fd->f_blob->size)
2033 fd->f_blob->size = offset + size;
2034
2035 touch_inode(fd->f_inode);
2036 return ret;
2037 }
2038
2039 static const struct fuse_operations wimfs_operations = {
2040 .chmod = wimfs_chmod,
2041 .chown = wimfs_chown,
2042 .fgetattr = wimfs_fgetattr,
2043 .ftruncate = wimfs_ftruncate,
2044 .getattr = wimfs_getattr,
2045 .getxattr = wimfs_getxattr,
2046 .link = wimfs_link,
2047 .listxattr = wimfs_listxattr,
2048 .mkdir = wimfs_mkdir,
2049 .mknod = wimfs_mknod,
2050 .open = wimfs_open,
2051 .opendir = wimfs_opendir,
2052 .read = wimfs_read,
2053 .readdir = wimfs_readdir,
2054 .readlink = wimfs_readlink,
2055 .release = wimfs_release,
2056 .releasedir = wimfs_release,
2057 .removexattr = wimfs_removexattr,
2058 .rename = wimfs_rename,
2059 .rmdir = wimfs_rmdir,
2060 .setxattr = wimfs_setxattr,
2061 .symlink = wimfs_symlink,
2062 .truncate = wimfs_truncate,
2063 .unlink = wimfs_unlink,
2064 #ifdef HAVE_UTIMENSAT
2065 .utimens = wimfs_utimens,
2066 #else
2067 .utime = wimfs_utime,
2068 #endif
2069 .write = wimfs_write,
2070
2071 /* We keep track of file descriptor structures (struct wimfs_fd), so
2072 * there is no need to have the file path provided on operations such as
2073 * read(). */
2074 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
2075 .flag_nullpath_ok = 1,
2076 #endif
2077 #if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 9)
2078 .flag_nopath = 1,
2079 .flag_utime_omit_ok = 1,
2080 #endif
2081 };
2082
2083 /* API function documented in wimlib.h */
2084 WIMLIBAPI int
wimlib_mount_image(WIMStruct * wim,int image,const char * dir,int mount_flags,const char * staging_dir)2085 wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
2086 int mount_flags, const char *staging_dir)
2087 {
2088 int ret;
2089 struct wim_image_metadata *imd;
2090 struct wimfs_context ctx;
2091 char *fuse_argv[16];
2092 int fuse_argc;
2093
2094 if (!wim || !dir || !*dir)
2095 return WIMLIB_ERR_INVALID_PARAM;
2096
2097 if (mount_flags & ~(WIMLIB_MOUNT_FLAG_READWRITE |
2098 WIMLIB_MOUNT_FLAG_DEBUG |
2099 WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
2100 WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
2101 WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS |
2102 WIMLIB_MOUNT_FLAG_UNIX_DATA |
2103 WIMLIB_MOUNT_FLAG_ALLOW_OTHER))
2104 return WIMLIB_ERR_INVALID_PARAM;
2105
2106 /* For read-write mount, check for write access to the WIM. */
2107 if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2108 if (!wim->filename)
2109 return WIMLIB_ERR_NO_FILENAME;
2110 ret = can_modify_wim(wim);
2111 if (ret)
2112 return ret;
2113 }
2114
2115 /* Select the image to mount. */
2116 ret = select_wim_image(wim, image);
2117 if (ret)
2118 return ret;
2119
2120 /* Get the metadata for the image to mount. */
2121 imd = wim_get_current_image_metadata(wim);
2122
2123 /* To avoid complicating things, we don't support mounting images to
2124 * which in-memory modifications have already been made. */
2125 if (is_image_dirty(imd)) {
2126 ERROR("Cannot mount a modified WIM image!");
2127 return WIMLIB_ERR_INVALID_PARAM;
2128 }
2129
2130 if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2131 if (imd->refcnt > 1)
2132 return WIMLIB_ERR_IMAGE_HAS_MULTIPLE_REFERENCES;
2133 ret = lock_wim_for_append(wim);
2134 if (ret)
2135 return ret;
2136 }
2137
2138 if (wim_has_solid_resources(wim)) {
2139 WARNING("Mounting a WIM file containing solid-compressed data; "
2140 "file access may be slow.");
2141 }
2142
2143 /* If the user did not specify an interface for accessing named
2144 * data streams, use the default (extended attributes). */
2145 if (!(mount_flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
2146 WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
2147 WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)))
2148 mount_flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
2149
2150 /* Start initializing the wimfs_context. */
2151 memset(&ctx, 0, sizeof(struct wimfs_context));
2152 ctx.wim = wim;
2153 ctx.mount_flags = mount_flags;
2154 if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
2155 ctx.default_lookup_flags = LOOKUP_FLAG_ADS_OK;
2156
2157 /* For read-write mounts, create the staging directory, save a reference
2158 * to the image's metadata resource, and mark the image dirty. */
2159 if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
2160 ret = make_staging_dir(&ctx, staging_dir);
2161 if (ret)
2162 goto out;
2163 ret = WIMLIB_ERR_NOMEM;
2164 ctx.metadata_resource = clone_blob_descriptor(
2165 imd->metadata_blob);
2166 if (!ctx.metadata_resource)
2167 goto out;
2168 mark_image_dirty(imd);
2169 }
2170 ctx.owner_uid = getuid();
2171 ctx.owner_gid = getgid();
2172
2173 /* Number the inodes in the mounted image sequentially and initialize
2174 * the file descriptor arrays */
2175 prepare_inodes(&ctx);
2176
2177 /* Save the absolute path to the mountpoint directory. */
2178 ctx.mountpoint_abspath = realpath(dir, NULL);
2179 if (ctx.mountpoint_abspath)
2180 ctx.mountpoint_abspath_nchars = strlen(ctx.mountpoint_abspath);
2181
2182 /* Build the FUSE command line. */
2183
2184 fuse_argc = 0;
2185 fuse_argv[fuse_argc++] = "wimlib";
2186 fuse_argv[fuse_argc++] = (char *)dir;
2187
2188 /* Disable multi-threaded operation. */
2189 fuse_argv[fuse_argc++] = "-s";
2190
2191 /* Enable FUSE debug mode (don't fork) if requested by the user. */
2192 if (mount_flags & WIMLIB_MOUNT_FLAG_DEBUG)
2193 fuse_argv[fuse_argc++] = "-d";
2194
2195 /*
2196 * Build the FUSE mount options:
2197 *
2198 * use_ino
2199 * FUSE will use the inode numbers we provide. We want this,
2200 * because we have inodes and will number them ourselves.
2201 *
2202 * subtype=wimfs
2203 * Name for our filesystem (main type is "fuse").
2204 *
2205 * hard_remove
2206 * If an open file is unlinked, unlink it for real rather than
2207 * renaming it to a hidden file. Our code supports this; an
2208 * unlinked inode is retained until all its file descriptors have
2209 * been closed.
2210 *
2211 * default_permissions
2212 * FUSE will perform permission checking. Useful when
2213 * WIMLIB_MOUNT_FLAG_UNIX_DATA is provided and the WIM image
2214 * contains the UNIX permissions for each file.
2215 *
2216 * kernel_cache
2217 * Cache the contents of files. This will speed up repeated access
2218 * to files on a mounted WIM image, since they won't need to be
2219 * decompressed repeatedly. This option is valid because data in
2220 * the WIM image should never be changed externally. (Although, if
2221 * someone really wanted to they could modify the WIM file or mess
2222 * with the staging directory; but then they're asking for
2223 * trouble.)
2224 *
2225 * entry_timeout=1000000000
2226 * Cache positive name lookups indefinitely, since names can only
2227 * be added, removed, or modified through the mounted filesystem
2228 * itself.
2229 *
2230 * negative_timeout=1000000000
2231 * Cache negative name lookups indefinitely, since names can only
2232 * be added, removed, or modified through the mounted filesystem
2233 * itself.
2234 *
2235 * attr_timeout=0
2236 * Don't cache file/directory attributes. This is needed as a
2237 * workaround for the fact that when caching attributes, the high
2238 * level interface to libfuse considers a file which has several
2239 * hard-linked names as several different files. (Otherwise, we
2240 * could cache our file/directory attributes indefinitely, since
2241 * they can only be changed through the mounted filesystem itself.)
2242 */
2243 char optstring[256] =
2244 "use_ino"
2245 ",subtype=wimfs"
2246 ",hard_remove"
2247 ",default_permissions"
2248 ",kernel_cache"
2249 ",entry_timeout=1000000000"
2250 ",negative_timeout=1000000000"
2251 ",attr_timeout=0"
2252 ;
2253 fuse_argv[fuse_argc++] = "-o";
2254 fuse_argv[fuse_argc++] = optstring;
2255 if (!(mount_flags & WIMLIB_MOUNT_FLAG_READWRITE))
2256 strcat(optstring, ",ro");
2257 if (mount_flags & WIMLIB_MOUNT_FLAG_ALLOW_OTHER)
2258 strcat(optstring, ",allow_other");
2259 fuse_argv[fuse_argc] = NULL;
2260
2261 /* Mount our filesystem. */
2262 ret = fuse_main(fuse_argc, fuse_argv, &wimfs_operations, &ctx);
2263
2264 /* Cleanup and return. */
2265 if (ret)
2266 ret = WIMLIB_ERR_FUSE;
2267 out:
2268 FREE(ctx.mountpoint_abspath);
2269 free_blob_descriptor(ctx.metadata_resource);
2270 if (ctx.staging_dir_name)
2271 delete_staging_dir(&ctx);
2272 unlock_wim_for_append(wim);
2273 return ret;
2274 }
2275
2276 struct commit_progress_thread_args {
2277 mqd_t mq;
2278 wimlib_progress_func_t progfunc;
2279 void *progctx;
2280 };
2281
2282 static void *
commit_progress_thread_proc(void * _args)2283 commit_progress_thread_proc(void *_args)
2284 {
2285 struct commit_progress_thread_args *args = _args;
2286 struct commit_progress_report report;
2287 ssize_t ret;
2288
2289 for (;;) {
2290 ret = mq_receive(args->mq,
2291 (char *)&report, sizeof(report), NULL);
2292 if (ret == sizeof(report)) {
2293 call_progress(args->progfunc, report.msg,
2294 &report.info, args->progctx);
2295 } else {
2296 if (ret == 0 || (ret < 0 && errno != EINTR))
2297 break;
2298 }
2299 }
2300 return NULL;
2301 }
2302
2303 static void
generate_message_queue_name(char name[WIMFS_MQUEUE_NAME_LEN+1])2304 generate_message_queue_name(char name[WIMFS_MQUEUE_NAME_LEN + 1])
2305 {
2306 name[0] = '/';
2307 memcpy(name + 1, "wimfs-", 6);
2308 get_random_alnum_chars(name + 7, WIMFS_MQUEUE_NAME_LEN - 7);
2309 name[WIMFS_MQUEUE_NAME_LEN] = '\0';
2310 }
2311
2312 static mqd_t
create_message_queue(const char * name)2313 create_message_queue(const char *name)
2314 {
2315 bool am_root;
2316 mode_t umask_save;
2317 mode_t mode;
2318 struct mq_attr attr;
2319 mqd_t mq;
2320
2321 memset(&attr, 0, sizeof(attr));
2322 attr.mq_maxmsg = 8;
2323 attr.mq_msgsize = sizeof(struct commit_progress_report);
2324
2325 am_root = (geteuid() == 0);
2326 if (am_root) {
2327 /* Filesystem mounted as normal user with --allow-other should
2328 * be able to send messages to root user, if they're doing the
2329 * unmount. */
2330 umask_save = umask(0);
2331 mode = 0666;
2332 } else {
2333 mode = 0600;
2334 }
2335 mq = mq_open(name, O_RDWR | O_CREAT | O_EXCL, mode, &attr);
2336 if (am_root)
2337 umask(umask_save);
2338 return mq;
2339 }
2340
2341 /* Unmount a read-only or read-write mounted WIM image. */
2342 static int
do_unmount(const char * dir)2343 do_unmount(const char *dir)
2344 {
2345 int status;
2346 ssize_t len;
2347
2348 len = getxattr(dir, "wimfs.unmount", &status, sizeof(int));
2349 if (len == sizeof(int))
2350 return status;
2351 else if (len < 0 && (errno == EACCES || errno == EPERM))
2352 return WIMLIB_ERR_NOT_PERMITTED_TO_UNMOUNT;
2353 else
2354 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2355 }
2356
2357 static int
set_unmount_info(const char * dir,const struct wimfs_unmount_info * unmount_info)2358 set_unmount_info(const char *dir, const struct wimfs_unmount_info *unmount_info)
2359 {
2360 if (!setxattr(dir, "wimfs.unmount_info",
2361 unmount_info, sizeof(struct wimfs_unmount_info), 0))
2362 return 0;
2363 else if (errno == EROFS)
2364 return 0;
2365 else if (errno == EACCES || errno == EPERM)
2366 return WIMLIB_ERR_NOT_PERMITTED_TO_UNMOUNT;
2367 else
2368 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2369 }
2370
2371 static int
do_unmount_discard(const char * dir)2372 do_unmount_discard(const char *dir)
2373 {
2374 int ret;
2375 struct wimfs_unmount_info unmount_info;
2376
2377 memset(&unmount_info, 0, sizeof(unmount_info));
2378
2379 ret = set_unmount_info(dir, &unmount_info);
2380 if (ret)
2381 return ret;
2382 return do_unmount(dir);
2383 }
2384
2385 /* Unmount a read-write mounted WIM image, committing the changes. */
2386 static int
do_unmount_commit(const char * dir,int unmount_flags,wimlib_progress_func_t progfunc,void * progctx)2387 do_unmount_commit(const char *dir, int unmount_flags,
2388 wimlib_progress_func_t progfunc, void *progctx)
2389 {
2390 struct wimfs_unmount_info unmount_info;
2391 mqd_t mq;
2392 struct commit_progress_thread_args args;
2393 pthread_t commit_progress_tid;
2394 int ret;
2395
2396 memset(&unmount_info, 0, sizeof(unmount_info));
2397 unmount_info.unmount_flags = unmount_flags;
2398
2399 /* The current thread will be stuck in getxattr() until the image is
2400 * committed. Create a thread to handle the progress messages. */
2401 if (progfunc) {
2402 generate_message_queue_name(unmount_info.mq_name);
2403
2404 mq = create_message_queue(unmount_info.mq_name);
2405 if (mq == (mqd_t)-1) {
2406 ERROR_WITH_ERRNO("Can't create POSIX message queue");
2407 return WIMLIB_ERR_MQUEUE;
2408 }
2409 args.mq = mq;
2410 args.progfunc = progfunc;
2411 args.progctx = progctx;
2412 ret = pthread_create(&commit_progress_tid, NULL,
2413 commit_progress_thread_proc, &args);
2414 if (ret) {
2415 errno = ret;
2416 ERROR_WITH_ERRNO("Can't create thread");
2417 ret = WIMLIB_ERR_NOMEM;
2418 goto out_delete_mq;
2419 }
2420 unmount_info.unmount_flags |= WIMLIB_UNMOUNT_FLAG_SEND_PROGRESS;
2421 }
2422
2423 ret = set_unmount_info(dir, &unmount_info);
2424 if (!ret)
2425 ret = do_unmount(dir);
2426 if (progfunc) {
2427 /* Terminate the progress thread. */
2428 char empty[1];
2429 mq_send(mq, empty, 0, 1);
2430 pthread_join(commit_progress_tid, NULL);
2431 }
2432 out_delete_mq:
2433 if (progfunc) {
2434 mq_close(mq);
2435 mq_unlink(unmount_info.mq_name);
2436 }
2437 return ret;
2438 }
2439
2440 static int
begin_unmount(const char * dir,int unmount_flags,int * mount_flags_ret,wimlib_progress_func_t progfunc,void * progctx)2441 begin_unmount(const char *dir, int unmount_flags, int *mount_flags_ret,
2442 wimlib_progress_func_t progfunc, void *progctx)
2443 {
2444 int mount_flags;
2445 int mounted_image;
2446 int wim_filename_len;
2447 union wimlib_progress_info progress;
2448
2449 if (getxattr(dir, "wimfs.mount_flags",
2450 &mount_flags, sizeof(int)) != sizeof(int))
2451 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2452
2453 *mount_flags_ret = mount_flags;
2454
2455 if (!progfunc)
2456 return 0;
2457
2458 if (getxattr(dir, "wimfs.mounted_image",
2459 &mounted_image, sizeof(int)) != sizeof(int))
2460 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2461
2462 wim_filename_len = getxattr(dir, "wimfs.wim_filename", NULL, 0);
2463 if (wim_filename_len < 0)
2464 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2465
2466 char wim_filename[wim_filename_len + 1];
2467 if (getxattr(dir, "wimfs.wim_filename",
2468 wim_filename, wim_filename_len) != wim_filename_len)
2469 return WIMLIB_ERR_NOT_A_MOUNTPOINT;
2470 wim_filename[wim_filename_len] = '\0';
2471
2472 progress.unmount.mountpoint = dir;
2473 progress.unmount.mounted_wim = wim_filename;
2474 progress.unmount.mounted_image = mounted_image;
2475 progress.unmount.mount_flags = mount_flags;
2476 progress.unmount.unmount_flags = unmount_flags;
2477
2478 return call_progress(progfunc, WIMLIB_PROGRESS_MSG_UNMOUNT_BEGIN,
2479 &progress, progctx);
2480 }
2481
2482 /* API function documented in wimlib.h */
2483 WIMLIBAPI int
wimlib_unmount_image_with_progress(const char * dir,int unmount_flags,wimlib_progress_func_t progfunc,void * progctx)2484 wimlib_unmount_image_with_progress(const char *dir, int unmount_flags,
2485 wimlib_progress_func_t progfunc, void *progctx)
2486 {
2487 int mount_flags;
2488 int ret;
2489
2490 ret = wimlib_global_init(0);
2491 if (ret)
2492 return ret;
2493
2494 if (unmount_flags & ~(WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY |
2495 WIMLIB_UNMOUNT_FLAG_COMMIT |
2496 WIMLIB_UNMOUNT_FLAG_REBUILD |
2497 WIMLIB_UNMOUNT_FLAG_RECOMPRESS |
2498 WIMLIB_UNMOUNT_FLAG_FORCE |
2499 WIMLIB_UNMOUNT_FLAG_NEW_IMAGE))
2500 return WIMLIB_ERR_INVALID_PARAM;
2501
2502 ret = begin_unmount(dir, unmount_flags, &mount_flags,
2503 progfunc, progctx);
2504 if (ret)
2505 return ret;
2506
2507 if ((unmount_flags & WIMLIB_UNMOUNT_FLAG_COMMIT) &&
2508 (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE))
2509 return do_unmount_commit(dir, unmount_flags,
2510 progfunc, progctx);
2511 else
2512 return do_unmount_discard(dir);
2513 }
2514
2515 #else /* WITH_FUSE */
2516
2517
2518 static int
mount_unsupported_error(void)2519 mount_unsupported_error(void)
2520 {
2521 #if defined(__WIN32__)
2522 ERROR("Sorry-- Mounting WIM images is not supported on Windows!");
2523 #else
2524 ERROR("wimlib was compiled with --without-fuse, which disables support "
2525 "for mounting WIMs.");
2526 #endif
2527 return WIMLIB_ERR_UNSUPPORTED;
2528 }
2529
2530 WIMLIBAPI int
wimlib_unmount_image_with_progress(const tchar * dir,int unmount_flags,wimlib_progress_func_t progfunc,void * progctx)2531 wimlib_unmount_image_with_progress(const tchar *dir, int unmount_flags,
2532 wimlib_progress_func_t progfunc, void *progctx)
2533 {
2534 return mount_unsupported_error();
2535 }
2536
2537 WIMLIBAPI int
wimlib_mount_image(WIMStruct * wim,int image,const tchar * dir,int mount_flags,const tchar * staging_dir)2538 wimlib_mount_image(WIMStruct *wim, int image, const tchar *dir,
2539 int mount_flags, const tchar *staging_dir)
2540 {
2541 return mount_unsupported_error();
2542 }
2543
2544 #endif /* !WITH_FUSE */
2545
2546 WIMLIBAPI int
wimlib_unmount_image(const tchar * dir,int unmount_flags)2547 wimlib_unmount_image(const tchar *dir, int unmount_flags)
2548 {
2549 return wimlib_unmount_image_with_progress(dir, unmount_flags, NULL, NULL);
2550 }
2551