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arm64: dts: allwinner: pinebook: Remove unused AXP803 regulators
[linux/fpc-iii.git] / fs / hostfs / hostfs_kern.c
blobe6b8c49076bbcdbebad6a557c744a6c1546c385d
1 /*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 *
5 * Ported the filesystem routines to 2.5.
6 * 2003-02-10 Petr Baudis <pasky@ucw.cz>
7 */
8
9 #include <linux/fs.h>
10 #include <linux/magic.h>
11 #include <linux/module.h>
12 #include <linux/mm.h>
13 #include <linux/pagemap.h>
14 #include <linux/statfs.h>
15 #include <linux/slab.h>
16 #include <linux/seq_file.h>
17 #include <linux/mount.h>
18 #include <linux/namei.h>
19 #include "hostfs.h"
20 #include <init.h>
21 #include <kern.h>
22
23 struct hostfs_inode_info {
24 int fd;
25 fmode_t mode;
26 struct inode vfs_inode;
27 struct mutex open_mutex;
28 };
29
30 static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
31 {
32 return list_entry(inode, struct hostfs_inode_info, vfs_inode);
33 }
34
35 #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file))
36
37 /* Changed in hostfs_args before the kernel starts running */
38 static char *root_ino = "";
39 static int append = 0;
40
41 static const struct inode_operations hostfs_iops;
42 static const struct inode_operations hostfs_dir_iops;
43 static const struct inode_operations hostfs_link_iops;
44
45 #ifndef MODULE
46 static int __init hostfs_args(char *options, int *add)
47 {
48 char *ptr;
49
50 ptr = strchr(options, ',');
51 if (ptr != NULL)
52 *ptr++ = '\0';
53 if (*options != '\0')
54 root_ino = options;
55
56 options = ptr;
57 while (options) {
58 ptr = strchr(options, ',');
59 if (ptr != NULL)
60 *ptr++ = '\0';
61 if (*options != '\0') {
62 if (!strcmp(options, "append"))
63 append = 1;
64 else printf("hostfs_args - unsupported option - %s\n",
65 options);
66 }
67 options = ptr;
68 }
69 return 0;
70 }
71
72 __uml_setup("hostfs=", hostfs_args,
73 "hostfs=<root dir>,<flags>,...\n"
74 " This is used to set hostfs parameters. The root directory argument\n"
75 " is used to confine all hostfs mounts to within the specified directory\n"
76 " tree on the host. If this isn't specified, then a user inside UML can\n"
77 " mount anything on the host that's accessible to the user that's running\n"
78 " it.\n"
79 " The only flag currently supported is 'append', which specifies that all\n"
80 " files opened by hostfs will be opened in append mode.\n\n"
81 );
82 #endif
83
84 static char *__dentry_name(struct dentry *dentry, char *name)
85 {
86 char *p = dentry_path_raw(dentry, name, PATH_MAX);
87 char *root;
88 size_t len;
89
90 root = dentry->d_sb->s_fs_info;
91 len = strlen(root);
92 if (IS_ERR(p)) {
93 __putname(name);
94 return NULL;
95 }
96
97 /*
98 * This function relies on the fact that dentry_path_raw() will place
99 * the path name at the end of the provided buffer.
100 */
101 BUG_ON(p + strlen(p) + 1 != name + PATH_MAX);
102
103 strlcpy(name, root, PATH_MAX);
104 if (len > p - name) {
105 __putname(name);
106 return NULL;
107 }
108
109 if (p > name + len)
110 strcpy(name + len, p);
111
112 return name;
113 }
114
115 static char *dentry_name(struct dentry *dentry)
116 {
117 char *name = __getname();
118 if (!name)
119 return NULL;
120
121 return __dentry_name(dentry, name);
122 }
123
124 static char *inode_name(struct inode *ino)
125 {
126 struct dentry *dentry;
127 char *name;
128
129 dentry = d_find_alias(ino);
130 if (!dentry)
131 return NULL;
132
133 name = dentry_name(dentry);
134
135 dput(dentry);
136
137 return name;
138 }
139
140 static char *follow_link(char *link)
141 {
142 int len, n;
143 char *name, *resolved, *end;
144
145 name = __getname();
146 if (!name) {
147 n = -ENOMEM;
148 goto out_free;
149 }
150
151 n = hostfs_do_readlink(link, name, PATH_MAX);
152 if (n < 0)
153 goto out_free;
154 else if (n == PATH_MAX) {
155 n = -E2BIG;
156 goto out_free;
157 }
158
159 if (*name == '/')
160 return name;
161
162 end = strrchr(link, '/');
163 if (end == NULL)
164 return name;
165
166 *(end + 1) = '\0';
167 len = strlen(link) + strlen(name) + 1;
168
169 resolved = kmalloc(len, GFP_KERNEL);
170 if (resolved == NULL) {
171 n = -ENOMEM;
172 goto out_free;
173 }
174
175 sprintf(resolved, "%s%s", link, name);
176 __putname(name);
177 kfree(link);
178 return resolved;
179
180 out_free:
181 __putname(name);
182 return ERR_PTR(n);
183 }
184
185 static struct inode *hostfs_iget(struct super_block *sb)
186 {
187 struct inode *inode = new_inode(sb);
188 if (!inode)
189 return ERR_PTR(-ENOMEM);
190 return inode;
191 }
192
193 static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
194 {
195 /*
196 * do_statfs uses struct statfs64 internally, but the linux kernel
197 * struct statfs still has 32-bit versions for most of these fields,
198 * so we convert them here
199 */
200 int err;
201 long long f_blocks;
202 long long f_bfree;
203 long long f_bavail;
204 long long f_files;
205 long long f_ffree;
206
207 err = do_statfs(dentry->d_sb->s_fs_info,
208 &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
209 &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
210 &sf->f_namelen);
211 if (err)
212 return err;
213 sf->f_blocks = f_blocks;
214 sf->f_bfree = f_bfree;
215 sf->f_bavail = f_bavail;
216 sf->f_files = f_files;
217 sf->f_ffree = f_ffree;
218 sf->f_type = HOSTFS_SUPER_MAGIC;
219 return 0;
220 }
221
222 static struct inode *hostfs_alloc_inode(struct super_block *sb)
223 {
224 struct hostfs_inode_info *hi;
225
226 hi = kmalloc(sizeof(*hi), GFP_KERNEL_ACCOUNT);
227 if (hi == NULL)
228 return NULL;
229 hi->fd = -1;
230 hi->mode = 0;
231 inode_init_once(&hi->vfs_inode);
232 mutex_init(&hi->open_mutex);
233 return &hi->vfs_inode;
234 }
235
236 static void hostfs_evict_inode(struct inode *inode)
237 {
238 truncate_inode_pages_final(&inode->i_data);
239 clear_inode(inode);
240 if (HOSTFS_I(inode)->fd != -1) {
241 close_file(&HOSTFS_I(inode)->fd);
242 HOSTFS_I(inode)->fd = -1;
243 }
244 }
245
246 static void hostfs_free_inode(struct inode *inode)
247 {
248 kfree(HOSTFS_I(inode));
249 }
250
251 static int hostfs_show_options(struct seq_file *seq, struct dentry *root)
252 {
253 const char *root_path = root->d_sb->s_fs_info;
254 size_t offset = strlen(root_ino) + 1;
255
256 if (strlen(root_path) > offset)
257 seq_show_option(seq, root_path + offset, NULL);
258
259 if (append)
260 seq_puts(seq, ",append");
261
262 return 0;
263 }
264
265 static const struct super_operations hostfs_sbops = {
266 .alloc_inode = hostfs_alloc_inode,
267 .free_inode = hostfs_free_inode,
268 .evict_inode = hostfs_evict_inode,
269 .statfs = hostfs_statfs,
270 .show_options = hostfs_show_options,
271 };
272
273 static int hostfs_readdir(struct file *file, struct dir_context *ctx)
274 {
275 void *dir;
276 char *name;
277 unsigned long long next, ino;
278 int error, len;
279 unsigned int type;
280
281 name = dentry_name(file->f_path.dentry);
282 if (name == NULL)
283 return -ENOMEM;
284 dir = open_dir(name, &error);
285 __putname(name);
286 if (dir == NULL)
287 return -error;
288 next = ctx->pos;
289 seek_dir(dir, next);
290 while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) {
291 if (!dir_emit(ctx, name, len, ino, type))
292 break;
293 ctx->pos = next;
294 }
295 close_dir(dir);
296 return 0;
297 }
298
299 static int hostfs_open(struct inode *ino, struct file *file)
300 {
301 char *name;
302 fmode_t mode;
303 int err;
304 int r, w, fd;
305
306 mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
307 if ((mode & HOSTFS_I(ino)->mode) == mode)
308 return 0;
309
310 mode |= HOSTFS_I(ino)->mode;
311
312 retry:
313 r = w = 0;
314
315 if (mode & FMODE_READ)
316 r = 1;
317 if (mode & FMODE_WRITE)
318 r = w = 1;
319
320 name = dentry_name(file->f_path.dentry);
321 if (name == NULL)
322 return -ENOMEM;
323
324 fd = open_file(name, r, w, append);
325 __putname(name);
326 if (fd < 0)
327 return fd;
328
329 mutex_lock(&HOSTFS_I(ino)->open_mutex);
330 /* somebody else had handled it first? */
331 if ((mode & HOSTFS_I(ino)->mode) == mode) {
332 mutex_unlock(&HOSTFS_I(ino)->open_mutex);
333 close_file(&fd);
334 return 0;
335 }
336 if ((mode | HOSTFS_I(ino)->mode) != mode) {
337 mode |= HOSTFS_I(ino)->mode;
338 mutex_unlock(&HOSTFS_I(ino)->open_mutex);
339 close_file(&fd);
340 goto retry;
341 }
342 if (HOSTFS_I(ino)->fd == -1) {
343 HOSTFS_I(ino)->fd = fd;
344 } else {
345 err = replace_file(fd, HOSTFS_I(ino)->fd);
346 close_file(&fd);
347 if (err < 0) {
348 mutex_unlock(&HOSTFS_I(ino)->open_mutex);
349 return err;
350 }
351 }
352 HOSTFS_I(ino)->mode = mode;
353 mutex_unlock(&HOSTFS_I(ino)->open_mutex);
354
355 return 0;
356 }
357
358 static int hostfs_file_release(struct inode *inode, struct file *file)
359 {
360 filemap_write_and_wait(inode->i_mapping);
361
362 return 0;
363 }
364
365 static int hostfs_fsync(struct file *file, loff_t start, loff_t end,
366 int datasync)
367 {
368 struct inode *inode = file->f_mapping->host;
369 int ret;
370
371 ret = file_write_and_wait_range(file, start, end);
372 if (ret)
373 return ret;
374
375 inode_lock(inode);
376 ret = fsync_file(HOSTFS_I(inode)->fd, datasync);
377 inode_unlock(inode);
378
379 return ret;
380 }
381
382 static const struct file_operations hostfs_file_fops = {
383 .llseek = generic_file_llseek,
384 .splice_read = generic_file_splice_read,
385 .read_iter = generic_file_read_iter,
386 .write_iter = generic_file_write_iter,
387 .mmap = generic_file_mmap,
388 .open = hostfs_open,
389 .release = hostfs_file_release,
390 .fsync = hostfs_fsync,
391 };
392
393 static const struct file_operations hostfs_dir_fops = {
394 .llseek = generic_file_llseek,
395 .iterate_shared = hostfs_readdir,
396 .read = generic_read_dir,
397 .open = hostfs_open,
398 .fsync = hostfs_fsync,
399 };
400
401 static int hostfs_writepage(struct page *page, struct writeback_control *wbc)
402 {
403 struct address_space *mapping = page->mapping;
404 struct inode *inode = mapping->host;
405 char *buffer;
406 loff_t base = page_offset(page);
407 int count = PAGE_SIZE;
408 int end_index = inode->i_size >> PAGE_SHIFT;
409 int err;
410
411 if (page->index >= end_index)
412 count = inode->i_size & (PAGE_SIZE-1);
413
414 buffer = kmap(page);
415
416 err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
417 if (err != count) {
418 ClearPageUptodate(page);
419 goto out;
420 }
421
422 if (base > inode->i_size)
423 inode->i_size = base;
424
425 if (PageError(page))
426 ClearPageError(page);
427 err = 0;
428
429 out:
430 kunmap(page);
431
432 unlock_page(page);
433 return err;
434 }
435
436 static int hostfs_readpage(struct file *file, struct page *page)
437 {
438 char *buffer;
439 loff_t start = page_offset(page);
440 int bytes_read, ret = 0;
441
442 buffer = kmap(page);
443 bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
444 PAGE_SIZE);
445 if (bytes_read < 0) {
446 ClearPageUptodate(page);
447 SetPageError(page);
448 ret = bytes_read;
449 goto out;
450 }
451
452 memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read);
453
454 ClearPageError(page);
455 SetPageUptodate(page);
456
457 out:
458 flush_dcache_page(page);
459 kunmap(page);
460 unlock_page(page);
461 return ret;
462 }
463
464 static int hostfs_write_begin(struct file *file, struct address_space *mapping,
465 loff_t pos, unsigned len, unsigned flags,
466 struct page **pagep, void **fsdata)
467 {
468 pgoff_t index = pos >> PAGE_SHIFT;
469
470 *pagep = grab_cache_page_write_begin(mapping, index, flags);
471 if (!*pagep)
472 return -ENOMEM;
473 return 0;
474 }
475
476 static int hostfs_write_end(struct file *file, struct address_space *mapping,
477 loff_t pos, unsigned len, unsigned copied,
478 struct page *page, void *fsdata)
479 {
480 struct inode *inode = mapping->host;
481 void *buffer;
482 unsigned from = pos & (PAGE_SIZE - 1);
483 int err;
484
485 buffer = kmap(page);
486 err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied);
487 kunmap(page);
488
489 if (!PageUptodate(page) && err == PAGE_SIZE)
490 SetPageUptodate(page);
491
492 /*
493 * If err > 0, write_file has added err to pos, so we are comparing
494 * i_size against the last byte written.
495 */
496 if (err > 0 && (pos > inode->i_size))
497 inode->i_size = pos;
498 unlock_page(page);
499 put_page(page);
500
501 return err;
502 }
503
504 static const struct address_space_operations hostfs_aops = {
505 .writepage = hostfs_writepage,
506 .readpage = hostfs_readpage,
507 .set_page_dirty = __set_page_dirty_nobuffers,
508 .write_begin = hostfs_write_begin,
509 .write_end = hostfs_write_end,
510 };
511
512 static int read_name(struct inode *ino, char *name)
513 {
514 dev_t rdev;
515 struct hostfs_stat st;
516 int err = stat_file(name, &st, -1);
517 if (err)
518 return err;
519
520 /* Reencode maj and min with the kernel encoding.*/
521 rdev = MKDEV(st.maj, st.min);
522
523 switch (st.mode & S_IFMT) {
524 case S_IFLNK:
525 ino->i_op = &hostfs_link_iops;
526 break;
527 case S_IFDIR:
528 ino->i_op = &hostfs_dir_iops;
529 ino->i_fop = &hostfs_dir_fops;
530 break;
531 case S_IFCHR:
532 case S_IFBLK:
533 case S_IFIFO:
534 case S_IFSOCK:
535 init_special_inode(ino, st.mode & S_IFMT, rdev);
536 ino->i_op = &hostfs_iops;
537 break;
538 case S_IFREG:
539 ino->i_op = &hostfs_iops;
540 ino->i_fop = &hostfs_file_fops;
541 ino->i_mapping->a_ops = &hostfs_aops;
542 break;
543 default:
544 return -EIO;
545 }
546
547 ino->i_ino = st.ino;
548 ino->i_mode = st.mode;
549 set_nlink(ino, st.nlink);
550 i_uid_write(ino, st.uid);
551 i_gid_write(ino, st.gid);
552 ino->i_atime = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec };
553 ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec };
554 ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec };
555 ino->i_size = st.size;
556 ino->i_blocks = st.blocks;
557 return 0;
558 }
559
560 static int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
561 bool excl)
562 {
563 struct inode *inode;
564 char *name;
565 int error, fd;
566
567 inode = hostfs_iget(dir->i_sb);
568 if (IS_ERR(inode)) {
569 error = PTR_ERR(inode);
570 goto out;
571 }
572
573 error = -ENOMEM;
574 name = dentry_name(dentry);
575 if (name == NULL)
576 goto out_put;
577
578 fd = file_create(name, mode & 0777);
579 if (fd < 0)
580 error = fd;
581 else
582 error = read_name(inode, name);
583
584 __putname(name);
585 if (error)
586 goto out_put;
587
588 HOSTFS_I(inode)->fd = fd;
589 HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
590 d_instantiate(dentry, inode);
591 return 0;
592
593 out_put:
594 iput(inode);
595 out:
596 return error;
597 }
598
599 static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
600 unsigned int flags)
601 {
602 struct inode *inode;
603 char *name;
604 int err;
605
606 inode = hostfs_iget(ino->i_sb);
607 if (IS_ERR(inode))
608 goto out;
609
610 err = -ENOMEM;
611 name = dentry_name(dentry);
612 if (name) {
613 err = read_name(inode, name);
614 __putname(name);
615 }
616 if (err) {
617 iput(inode);
618 inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
619 }
620 out:
621 return d_splice_alias(inode, dentry);
622 }
623
624 static int hostfs_link(struct dentry *to, struct inode *ino,
625 struct dentry *from)
626 {
627 char *from_name, *to_name;
628 int err;
629
630 if ((from_name = dentry_name(from)) == NULL)
631 return -ENOMEM;
632 to_name = dentry_name(to);
633 if (to_name == NULL) {
634 __putname(from_name);
635 return -ENOMEM;
636 }
637 err = link_file(to_name, from_name);
638 __putname(from_name);
639 __putname(to_name);
640 return err;
641 }
642
643 static int hostfs_unlink(struct inode *ino, struct dentry *dentry)
644 {
645 char *file;
646 int err;
647
648 if (append)
649 return -EPERM;
650
651 if ((file = dentry_name(dentry)) == NULL)
652 return -ENOMEM;
653
654 err = unlink_file(file);
655 __putname(file);
656 return err;
657 }
658
659 static int hostfs_symlink(struct inode *ino, struct dentry *dentry,
660 const char *to)
661 {
662 char *file;
663 int err;
664
665 if ((file = dentry_name(dentry)) == NULL)
666 return -ENOMEM;
667 err = make_symlink(file, to);
668 __putname(file);
669 return err;
670 }
671
672 static int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode)
673 {
674 char *file;
675 int err;
676
677 if ((file = dentry_name(dentry)) == NULL)
678 return -ENOMEM;
679 err = do_mkdir(file, mode);
680 __putname(file);
681 return err;
682 }
683
684 static int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
685 {
686 char *file;
687 int err;
688
689 if ((file = dentry_name(dentry)) == NULL)
690 return -ENOMEM;
691 err = hostfs_do_rmdir(file);
692 __putname(file);
693 return err;
694 }
695
696 static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
697 {
698 struct inode *inode;
699 char *name;
700 int err;
701
702 inode = hostfs_iget(dir->i_sb);
703 if (IS_ERR(inode)) {
704 err = PTR_ERR(inode);
705 goto out;
706 }
707
708 err = -ENOMEM;
709 name = dentry_name(dentry);
710 if (name == NULL)
711 goto out_put;
712
713 init_special_inode(inode, mode, dev);
714 err = do_mknod(name, mode, MAJOR(dev), MINOR(dev));
715 if (err)
716 goto out_free;
717
718 err = read_name(inode, name);
719 __putname(name);
720 if (err)
721 goto out_put;
722
723 d_instantiate(dentry, inode);
724 return 0;
725
726 out_free:
727 __putname(name);
728 out_put:
729 iput(inode);
730 out:
731 return err;
732 }
733
734 static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
735 struct inode *new_dir, struct dentry *new_dentry,
736 unsigned int flags)
737 {
738 char *old_name, *new_name;
739 int err;
740
741 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
742 return -EINVAL;
743
744 old_name = dentry_name(old_dentry);
745 if (old_name == NULL)
746 return -ENOMEM;
747 new_name = dentry_name(new_dentry);
748 if (new_name == NULL) {
749 __putname(old_name);
750 return -ENOMEM;
751 }
752 if (!flags)
753 err = rename_file(old_name, new_name);
754 else
755 err = rename2_file(old_name, new_name, flags);
756
757 __putname(old_name);
758 __putname(new_name);
759 return err;
760 }
761
762 static int hostfs_permission(struct inode *ino, int desired)
763 {
764 char *name;
765 int r = 0, w = 0, x = 0, err;
766
767 if (desired & MAY_NOT_BLOCK)
768 return -ECHILD;
769
770 if (desired & MAY_READ) r = 1;
771 if (desired & MAY_WRITE) w = 1;
772 if (desired & MAY_EXEC) x = 1;
773 name = inode_name(ino);
774 if (name == NULL)
775 return -ENOMEM;
776
777 if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) ||
778 S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode))
779 err = 0;
780 else
781 err = access_file(name, r, w, x);
782 __putname(name);
783 if (!err)
784 err = generic_permission(ino, desired);
785 return err;
786 }
787
788 static int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
789 {
790 struct inode *inode = d_inode(dentry);
791 struct hostfs_iattr attrs;
792 char *name;
793 int err;
794
795 int fd = HOSTFS_I(inode)->fd;
796
797 err = setattr_prepare(dentry, attr);
798 if (err)
799 return err;
800
801 if (append)
802 attr->ia_valid &= ~ATTR_SIZE;
803
804 attrs.ia_valid = 0;
805 if (attr->ia_valid & ATTR_MODE) {
806 attrs.ia_valid |= HOSTFS_ATTR_MODE;
807 attrs.ia_mode = attr->ia_mode;
808 }
809 if (attr->ia_valid & ATTR_UID) {
810 attrs.ia_valid |= HOSTFS_ATTR_UID;
811 attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid);
812 }
813 if (attr->ia_valid & ATTR_GID) {
814 attrs.ia_valid |= HOSTFS_ATTR_GID;
815 attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid);
816 }
817 if (attr->ia_valid & ATTR_SIZE) {
818 attrs.ia_valid |= HOSTFS_ATTR_SIZE;
819 attrs.ia_size = attr->ia_size;
820 }
821 if (attr->ia_valid & ATTR_ATIME) {
822 attrs.ia_valid |= HOSTFS_ATTR_ATIME;
823 attrs.ia_atime = (struct hostfs_timespec)
824 { attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec };
825 }
826 if (attr->ia_valid & ATTR_MTIME) {
827 attrs.ia_valid |= HOSTFS_ATTR_MTIME;
828 attrs.ia_mtime = (struct hostfs_timespec)
829 { attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec };
830 }
831 if (attr->ia_valid & ATTR_CTIME) {
832 attrs.ia_valid |= HOSTFS_ATTR_CTIME;
833 attrs.ia_ctime = (struct hostfs_timespec)
834 { attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec };
835 }
836 if (attr->ia_valid & ATTR_ATIME_SET) {
837 attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET;
838 }
839 if (attr->ia_valid & ATTR_MTIME_SET) {
840 attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET;
841 }
842 name = dentry_name(dentry);
843 if (name == NULL)
844 return -ENOMEM;
845 err = set_attr(name, &attrs, fd);
846 __putname(name);
847 if (err)
848 return err;
849
850 if ((attr->ia_valid & ATTR_SIZE) &&
851 attr->ia_size != i_size_read(inode))
852 truncate_setsize(inode, attr->ia_size);
853
854 setattr_copy(inode, attr);
855 mark_inode_dirty(inode);
856 return 0;
857 }
858
859 static const struct inode_operations hostfs_iops = {
860 .permission = hostfs_permission,
861 .setattr = hostfs_setattr,
862 };
863
864 static const struct inode_operations hostfs_dir_iops = {
865 .create = hostfs_create,
866 .lookup = hostfs_lookup,
867 .link = hostfs_link,
868 .unlink = hostfs_unlink,
869 .symlink = hostfs_symlink,
870 .mkdir = hostfs_mkdir,
871 .rmdir = hostfs_rmdir,
872 .mknod = hostfs_mknod,
873 .rename = hostfs_rename2,
874 .permission = hostfs_permission,
875 .setattr = hostfs_setattr,
876 };
877
878 static const char *hostfs_get_link(struct dentry *dentry,
879 struct inode *inode,
880 struct delayed_call *done)
881 {
882 char *link;
883 if (!dentry)
884 return ERR_PTR(-ECHILD);
885 link = kmalloc(PATH_MAX, GFP_KERNEL);
886 if (link) {
887 char *path = dentry_name(dentry);
888 int err = -ENOMEM;
889 if (path) {
890 err = hostfs_do_readlink(path, link, PATH_MAX);
891 if (err == PATH_MAX)
892 err = -E2BIG;
893 __putname(path);
894 }
895 if (err < 0) {
896 kfree(link);
897 return ERR_PTR(err);
898 }
899 } else {
900 return ERR_PTR(-ENOMEM);
901 }
902
903 set_delayed_call(done, kfree_link, link);
904 return link;
905 }
906
907 static const struct inode_operations hostfs_link_iops = {
908 .get_link = hostfs_get_link,
909 };
910
911 static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
912 {
913 struct inode *root_inode;
914 char *host_root_path, *req_root = d;
915 int err;
916
917 sb->s_blocksize = 1024;
918 sb->s_blocksize_bits = 10;
919 sb->s_magic = HOSTFS_SUPER_MAGIC;
920 sb->s_op = &hostfs_sbops;
921 sb->s_d_op = &simple_dentry_operations;
922 sb->s_maxbytes = MAX_LFS_FILESIZE;
923
924 /* NULL is printed as <NULL> by sprintf: avoid that. */
925 if (req_root == NULL)
926 req_root = "";
927
928 err = -ENOMEM;
929 sb->s_fs_info = host_root_path =
930 kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL);
931 if (host_root_path == NULL)
932 goto out;
933
934 sprintf(host_root_path, "%s/%s", root_ino, req_root);
935
936 root_inode = new_inode(sb);
937 if (!root_inode)
938 goto out;
939
940 err = read_name(root_inode, host_root_path);
941 if (err)
942 goto out_put;
943
944 if (S_ISLNK(root_inode->i_mode)) {
945 char *name = follow_link(host_root_path);
946 if (IS_ERR(name)) {
947 err = PTR_ERR(name);
948 goto out_put;
949 }
950 err = read_name(root_inode, name);
951 kfree(name);
952 if (err)
953 goto out_put;
954 }
955
956 err = -ENOMEM;
957 sb->s_root = d_make_root(root_inode);
958 if (sb->s_root == NULL)
959 goto out;
960
961 return 0;
962
963 out_put:
964 iput(root_inode);
965 out:
966 return err;
967 }
968
969 static struct dentry *hostfs_read_sb(struct file_system_type *type,
970 int flags, const char *dev_name,
971 void *data)
972 {
973 return mount_nodev(type, flags, data, hostfs_fill_sb_common);
974 }
975
976 static void hostfs_kill_sb(struct super_block *s)
977 {
978 kill_anon_super(s);
979 kfree(s->s_fs_info);
980 }
981
982 static struct file_system_type hostfs_type = {
983 .owner = THIS_MODULE,
984 .name = "hostfs",
985 .mount = hostfs_read_sb,
986 .kill_sb = hostfs_kill_sb,
987 .fs_flags = 0,
988 };
989 MODULE_ALIAS_FS("hostfs");
990
991 static int __init init_hostfs(void)
992 {
993 return register_filesystem(&hostfs_type);
994 }
995
996 static void __exit exit_hostfs(void)
997 {
998 unregister_filesystem(&hostfs_type);
999 }
1000
1001 module_init(init_hostfs)
1002 module_exit(exit_hostfs)
1003 MODULE_LICENSE("GPL");
Linux with added FPC-III support