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initial commit with v2.6.9
[linux-2.6.9-moxart.git] / fs / hostfs / hostfs_kern.c
blob7d42da0a304d46b6f6c7338353584ffe49f88e14
1 /*
2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.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/stddef.h>
10 #include <linux/fs.h>
11 #include <linux/version.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/pagemap.h>
16 #include <linux/blkdev.h>
17 #include <linux/list.h>
18 #include <linux/buffer_head.h>
19 #include <linux/root_dev.h>
20 #include <linux/statfs.h>
21 #include <linux/kdev_t.h>
22 #include <asm/uaccess.h>
23 #include "hostfs.h"
24 #include "kern_util.h"
25 #include "kern.h"
26 #include "user_util.h"
27 #include "2_5compat.h"
28 #include "init.h"
29
30 struct hostfs_inode_info {
31 char *host_filename;
32 int fd;
33 int mode;
34 struct inode vfs_inode;
35 };
36
37 static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
38 {
39 return(list_entry(inode, struct hostfs_inode_info, vfs_inode));
40 }
41
42 #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_dentry->d_inode)
43
44 int hostfs_d_delete(struct dentry *dentry)
45 {
46 return(1);
47 }
48
49 struct dentry_operations hostfs_dentry_ops = {
50 .d_delete = hostfs_d_delete,
51 };
52
53 /* Changed in hostfs_args before the kernel starts running */
54 static char *root_ino = "/";
55 static int append = 0;
56
57 #define HOSTFS_SUPER_MAGIC 0x00c0ffee
58
59 static struct inode_operations hostfs_iops;
60 static struct inode_operations hostfs_dir_iops;
61 static struct address_space_operations hostfs_link_aops;
62
63 #ifndef MODULE
64 static int __init hostfs_args(char *options, int *add)
65 {
66 char *ptr;
67
68 ptr = strchr(options, ',');
69 if(ptr != NULL)
70 *ptr++ = '\0';
71 if(*options != '\0')
72 root_ino = options;
73
74 options = ptr;
75 while(options){
76 ptr = strchr(options, ',');
77 if(ptr != NULL)
78 *ptr++ = '\0';
79 if(*options != '\0'){
80 if(!strcmp(options, "append"))
81 append = 1;
82 else printf("hostfs_args - unsupported option - %s\n",
83 options);
84 }
85 options = ptr;
86 }
87 return(0);
88 }
89
90 __uml_setup("hostfs=", hostfs_args,
91 "hostfs=<root dir>,<flags>,...\n"
92 " This is used to set hostfs parameters. The root directory argument\n"
93 " is used to confine all hostfs mounts to within the specified directory\n"
94 " tree on the host. If this isn't specified, then a user inside UML can\n"
95 " mount anything on the host that's accessible to the user that's running\n"
96 " it.\n"
97 " The only flag currently supported is 'append', which specifies that all\n"
98 " files opened by hostfs will be opened in append mode.\n\n"
99 );
100 #endif
101
102 static char *dentry_name(struct dentry *dentry, int extra)
103 {
104 struct dentry *parent;
105 char *root, *name;
106 int len;
107
108 len = 0;
109 parent = dentry;
110 while(parent->d_parent != parent){
111 len += parent->d_name.len + 1;
112 parent = parent->d_parent;
113 }
114
115 root = HOSTFS_I(parent->d_inode)->host_filename;
116 len += strlen(root);
117 name = kmalloc(len + extra + 1, GFP_KERNEL);
118 if(name == NULL) return(NULL);
119
120 name[len] = '\0';
121 parent = dentry;
122 while(parent->d_parent != parent){
123 len -= parent->d_name.len + 1;
124 name[len] = '/';
125 strncpy(&name[len + 1], parent->d_name.name,
126 parent->d_name.len);
127 parent = parent->d_parent;
128 }
129 strncpy(name, root, strlen(root));
130 return(name);
131 }
132
133 static char *inode_name(struct inode *ino, int extra)
134 {
135 struct dentry *dentry;
136
137 dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias);
138 return(dentry_name(dentry, extra));
139 }
140
141 static int read_name(struct inode *ino, char *name)
142 {
143 /* The non-int inode fields are copied into ints by stat_file and
144 * then copied into the inode because passing the actual pointers
145 * in and having them treated as int * breaks on big-endian machines
146 */
147 int err;
148 int i_mode, i_nlink, i_blksize;
149 unsigned long long i_size;
150 unsigned long long i_ino;
151 unsigned long long i_blocks;
152
153 err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid,
154 &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime,
155 &ino->i_ctime, &i_blksize, &i_blocks);
156 if(err)
157 return(err);
158
159 ino->i_ino = i_ino;
160 ino->i_mode = i_mode;
161 ino->i_nlink = i_nlink;
162 ino->i_size = i_size;
163 ino->i_blksize = i_blksize;
164 ino->i_blocks = i_blocks;
165 if((ino->i_sb->s_dev == ROOT_DEV) && (ino->i_uid == getuid()))
166 ino->i_uid = 0;
167 return(0);
168 }
169
170 static char *follow_link(char *link)
171 {
172 int len, n;
173 char *name, *resolved, *end;
174
175 len = 64;
176 while(1){
177 n = -ENOMEM;
178 name = kmalloc(len, GFP_KERNEL);
179 if(name == NULL)
180 goto out;
181
182 n = do_readlink(link, name, len);
183 if(n < len)
184 break;
185 len *= 2;
186 kfree(name);
187 }
188 if(n < 0)
189 goto out_free;
190
191 if(*name == '/')
192 return(name);
193
194 end = strrchr(link, '/');
195 if(end == NULL)
196 return(name);
197
198 *(end + 1) = '\0';
199 len = strlen(link) + strlen(name) + 1;
200
201 resolved = kmalloc(len, GFP_KERNEL);
202 if(resolved == NULL){
203 n = -ENOMEM;
204 goto out_free;
205 }
206
207 sprintf(resolved, "%s%s", link, name);
208 kfree(name);
209 kfree(link);
210 return(resolved);
211
212 out_free:
213 kfree(name);
214 out:
215 return(ERR_PTR(n));
216 }
217
218 static int read_inode(struct inode *ino)
219 {
220 char *name;
221 int err = 0;
222
223 /* Unfortunately, we are called from iget() when we don't have a dentry
224 * allocated yet.
225 */
226 if(list_empty(&ino->i_dentry))
227 goto out;
228
229 err = -ENOMEM;
230 name = inode_name(ino, 0);
231 if(name == NULL)
232 goto out;
233
234 if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){
235 name = follow_link(name);
236 if(IS_ERR(name)){
237 err = PTR_ERR(name);
238 goto out;
239 }
240 }
241
242 err = read_name(ino, name);
243 kfree(name);
244 out:
245 return(err);
246 }
247
248 int hostfs_statfs(struct super_block *sb, struct kstatfs *sf)
249 {
250 /* do_statfs uses struct statfs64 internally, but the linux kernel
251 * struct statfs still has 32-bit versions for most of these fields,
252 * so we convert them here
253 */
254 int err;
255 long long f_blocks;
256 long long f_bfree;
257 long long f_bavail;
258 long long f_files;
259 long long f_ffree;
260
261 err = do_statfs(HOSTFS_I(sb->s_root->d_inode)->host_filename,
262 &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
263 &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
264 &sf->f_namelen, sf->f_spare);
265 if(err) return(err);
266 sf->f_blocks = f_blocks;
267 sf->f_bfree = f_bfree;
268 sf->f_bavail = f_bavail;
269 sf->f_files = f_files;
270 sf->f_ffree = f_ffree;
271 sf->f_type = HOSTFS_SUPER_MAGIC;
272 return(0);
273 }
274
275 static struct inode *hostfs_alloc_inode(struct super_block *sb)
276 {
277 struct hostfs_inode_info *hi;
278
279 hi = kmalloc(sizeof(*hi), GFP_KERNEL);
280 if(hi == NULL)
281 return(NULL);
282
283 *hi = ((struct hostfs_inode_info) { .host_filename = NULL,
284 .fd = -1,
285 .mode = 0 });
286 inode_init_once(&hi->vfs_inode);
287 return(&hi->vfs_inode);
288 }
289
290 static void hostfs_delete_inode(struct inode *inode)
291 {
292 if(HOSTFS_I(inode)->fd != -1) {
293 close_file(&HOSTFS_I(inode)->fd);
294 HOSTFS_I(inode)->fd = -1;
295 }
296 clear_inode(inode);
297 }
298
299 static void hostfs_destroy_inode(struct inode *inode)
300 {
301 if(HOSTFS_I(inode)->host_filename)
302 kfree(HOSTFS_I(inode)->host_filename);
303
304 /*XXX: This should not happen, probably. The check is here for
305 * additional safety.*/
306 if(HOSTFS_I(inode)->fd != -1) {
307 close_file(&HOSTFS_I(inode)->fd);
308 printk(KERN_DEBUG "Closing host fd in .destroy_inode\n");
309 }
310
311 kfree(HOSTFS_I(inode));
312 }
313
314 static void hostfs_read_inode(struct inode *inode)
315 {
316 read_inode(inode);
317 }
318
319 static struct super_operations hostfs_sbops = {
320 .alloc_inode = hostfs_alloc_inode,
321 .drop_inode = generic_delete_inode,
322 .delete_inode = hostfs_delete_inode,
323 .destroy_inode = hostfs_destroy_inode,
324 .read_inode = hostfs_read_inode,
325 .statfs = hostfs_statfs,
326 };
327
328 int hostfs_readdir(struct file *file, void *ent, filldir_t filldir)
329 {
330 void *dir;
331 char *name;
332 unsigned long long next, ino;
333 int error, len;
334
335 name = dentry_name(file->f_dentry, 0);
336 if(name == NULL) return(-ENOMEM);
337 dir = open_dir(name, &error);
338 kfree(name);
339 if(dir == NULL) return(-error);
340 next = file->f_pos;
341 while((name = read_dir(dir, &next, &ino, &len)) != NULL){
342 error = (*filldir)(ent, name, len, file->f_pos,
343 ino, DT_UNKNOWN);
344 if(error) break;
345 file->f_pos = next;
346 }
347 close_dir(dir);
348 return(0);
349 }
350
351 int hostfs_file_open(struct inode *ino, struct file *file)
352 {
353 char *name;
354 int mode = 0, r = 0, w = 0, fd;
355
356 mode = file->f_mode & (FMODE_READ | FMODE_WRITE);
357 if((mode & HOSTFS_I(ino)->mode) == mode)
358 return(0);
359
360 /* The file may already have been opened, but with the wrong access,
361 * so this resets things and reopens the file with the new access.
362 */
363 if(HOSTFS_I(ino)->fd != -1){
364 close_file(&HOSTFS_I(ino)->fd);
365 HOSTFS_I(ino)->fd = -1;
366 }
367
368 HOSTFS_I(ino)->mode |= mode;
369 if(HOSTFS_I(ino)->mode & FMODE_READ)
370 r = 1;
371 if(HOSTFS_I(ino)->mode & FMODE_WRITE)
372 w = 1;
373 if(w)
374 r = 1;
375
376 name = dentry_name(file->f_dentry, 0);
377 if(name == NULL)
378 return(-ENOMEM);
379
380 fd = open_file(name, r, w, append);
381 kfree(name);
382 if(fd < 0) return(fd);
383 FILE_HOSTFS_I(file)->fd = fd;
384
385 return(0);
386 }
387
388 int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync)
389 {
390 return(0);
391 }
392
393 static struct file_operations hostfs_file_fops = {
394 .llseek = generic_file_llseek,
395 .read = generic_file_read,
396 .write = generic_file_write,
397 .mmap = generic_file_mmap,
398 .open = hostfs_file_open,
399 .release = NULL,
400 .fsync = hostfs_fsync,
401 };
402
403 static struct file_operations hostfs_dir_fops = {
404 .readdir = hostfs_readdir,
405 .read = generic_read_dir,
406 };
407
408 int hostfs_writepage(struct page *page, struct writeback_control *wbc)
409 {
410 struct address_space *mapping = page->mapping;
411 struct inode *inode = mapping->host;
412 char *buffer;
413 unsigned long long base;
414 int count = PAGE_CACHE_SIZE;
415 int end_index = inode->i_size >> PAGE_CACHE_SHIFT;
416 int err;
417
418 if (page->index >= end_index)
419 count = inode->i_size & (PAGE_CACHE_SIZE-1);
420
421 buffer = kmap(page);
422 base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT;
423
424 err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count);
425 if(err != count){
426 ClearPageUptodate(page);
427 goto out;
428 }
429
430 if (base > inode->i_size)
431 inode->i_size = base;
432
433 if (PageError(page))
434 ClearPageError(page);
435 err = 0;
436
437 out:
438 kunmap(page);
439
440 unlock_page(page);
441 return err;
442 }
443
444 int hostfs_readpage(struct file *file, struct page *page)
445 {
446 char *buffer;
447 long long start;
448 int err = 0;
449
450 start = (long long) page->index << PAGE_CACHE_SHIFT;
451 buffer = kmap(page);
452 err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
453 PAGE_CACHE_SIZE);
454 if(err < 0) goto out;
455
456 memset(&buffer[err], 0, PAGE_CACHE_SIZE - err);
457
458 flush_dcache_page(page);
459 SetPageUptodate(page);
460 if (PageError(page)) ClearPageError(page);
461 err = 0;
462 out:
463 kunmap(page);
464 unlock_page(page);
465 return(err);
466 }
467
468 int hostfs_prepare_write(struct file *file, struct page *page,
469 unsigned int from, unsigned int to)
470 {
471 char *buffer;
472 long long start, tmp;
473 int err;
474
475 start = (long long) page->index << PAGE_CACHE_SHIFT;
476 buffer = kmap(page);
477 if(from != 0){
478 tmp = start;
479 err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer,
480 from);
481 if(err < 0) goto out;
482 }
483 if(to != PAGE_CACHE_SIZE){
484 start += to;
485 err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to,
486 PAGE_CACHE_SIZE - to);
487 if(err < 0) goto out;
488 }
489 err = 0;
490 out:
491 kunmap(page);
492 return(err);
493 }
494
495 int hostfs_commit_write(struct file *file, struct page *page, unsigned from,
496 unsigned to)
497 {
498 struct address_space *mapping = page->mapping;
499 struct inode *inode = mapping->host;
500 char *buffer;
501 long long start;
502 int err = 0;
503
504 start = (long long) (page->index << PAGE_CACHE_SHIFT) + from;
505 buffer = kmap(page);
506 err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from,
507 to - from);
508 if(err > 0) err = 0;
509 if(!err && (start > inode->i_size))
510 inode->i_size = start;
511
512 kunmap(page);
513 return(err);
514 }
515
516 static struct address_space_operations hostfs_aops = {
517 .writepage = hostfs_writepage,
518 .readpage = hostfs_readpage,
519 /* .set_page_dirty = __set_page_dirty_nobuffers, */
520 .prepare_write = hostfs_prepare_write,
521 .commit_write = hostfs_commit_write
522 };
523
524 static int init_inode(struct inode *inode, struct dentry *dentry)
525 {
526 char *name;
527 int type, err = -ENOMEM;
528 int maj, min;
529 dev_t rdev = 0;
530
531 if(dentry){
532 name = dentry_name(dentry, 0);
533 if(name == NULL)
534 goto out;
535 type = file_type(name, &maj, &min);
536 /*Reencode maj and min with the kernel encoding.*/
537 rdev = MKDEV(maj, min);
538 kfree(name);
539 }
540 else type = OS_TYPE_DIR;
541
542 err = 0;
543 if(type == OS_TYPE_SYMLINK)
544 inode->i_op = &page_symlink_inode_operations;
545 else if(type == OS_TYPE_DIR)
546 inode->i_op = &hostfs_dir_iops;
547 else inode->i_op = &hostfs_iops;
548
549 if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops;
550 else inode->i_fop = &hostfs_file_fops;
551
552 if(type == OS_TYPE_SYMLINK)
553 inode->i_mapping->a_ops = &hostfs_link_aops;
554 else inode->i_mapping->a_ops = &hostfs_aops;
555
556 switch (type) {
557 case OS_TYPE_CHARDEV:
558 init_special_inode(inode, S_IFCHR, rdev);
559 break;
560 case OS_TYPE_BLOCKDEV:
561 init_special_inode(inode, S_IFBLK, rdev);
562 break;
563 case OS_TYPE_FIFO:
564 init_special_inode(inode, S_IFIFO, 0);
565 break;
566 case OS_TYPE_SOCK:
567 init_special_inode(inode, S_IFSOCK, 0);
568 break;
569 }
570 out:
571 return(err);
572 }
573
574 int hostfs_create(struct inode *dir, struct dentry *dentry, int mode,
575 struct nameidata *nd)
576 {
577 struct inode *inode;
578 char *name;
579 int error, fd;
580
581 error = -ENOMEM;
582 inode = iget(dir->i_sb, 0);
583 if(inode == NULL) goto out;
584
585 error = init_inode(inode, dentry);
586 if(error)
587 goto out_put;
588
589 error = -ENOMEM;
590 name = dentry_name(dentry, 0);
591 if(name == NULL)
592 goto out_put;
593
594 fd = file_create(name,
595 mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR,
596 mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP,
597 mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH);
598 if(fd < 0)
599 error = fd;
600 else error = read_name(inode, name);
601
602 kfree(name);
603 if(error)
604 goto out_put;
605
606 HOSTFS_I(inode)->fd = fd;
607 HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
608 d_instantiate(dentry, inode);
609 return(0);
610
611 out_put:
612 iput(inode);
613 out:
614 return(error);
615 }
616
617 struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
618 struct nameidata *nd)
619 {
620 struct inode *inode;
621 char *name;
622 int err;
623
624 err = -ENOMEM;
625 inode = iget(ino->i_sb, 0);
626 if(inode == NULL)
627 goto out;
628
629 err = init_inode(inode, dentry);
630 if(err)
631 goto out_put;
632
633 err = -ENOMEM;
634 name = dentry_name(dentry, 0);
635 if(name == NULL)
636 goto out_put;
637
638 err = read_name(inode, name);
639 kfree(name);
640 if(err == -ENOENT){
641 iput(inode);
642 inode = NULL;
643 }
644 else if(err)
645 goto out_put;
646
647 d_add(dentry, inode);
648 dentry->d_op = &hostfs_dentry_ops;
649 return(NULL);
650
651 out_put:
652 iput(inode);
653 out:
654 return(ERR_PTR(err));
655 }
656
657 static char *inode_dentry_name(struct inode *ino, struct dentry *dentry)
658 {
659 char *file;
660 int len;
661
662 file = inode_name(ino, dentry->d_name.len + 1);
663 if(file == NULL) return(NULL);
664 strcat(file, "/");
665 len = strlen(file);
666 strncat(file, dentry->d_name.name, dentry->d_name.len);
667 file[len + dentry->d_name.len] = '\0';
668 return(file);
669 }
670
671 int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from)
672 {
673 char *from_name, *to_name;
674 int err;
675
676 if((from_name = inode_dentry_name(ino, from)) == NULL)
677 return(-ENOMEM);
678 to_name = dentry_name(to, 0);
679 if(to_name == NULL){
680 kfree(from_name);
681 return(-ENOMEM);
682 }
683 err = link_file(to_name, from_name);
684 kfree(from_name);
685 kfree(to_name);
686 return(err);
687 }
688
689 int hostfs_unlink(struct inode *ino, struct dentry *dentry)
690 {
691 char *file;
692 int err;
693
694 if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
695 if(append)
696 return(-EPERM);
697
698 err = unlink_file(file);
699 kfree(file);
700 return(err);
701 }
702
703 int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to)
704 {
705 char *file;
706 int err;
707
708 if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
709 err = make_symlink(file, to);
710 kfree(file);
711 return(err);
712 }
713
714 int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode)
715 {
716 char *file;
717 int err;
718
719 if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
720 err = do_mkdir(file, mode);
721 kfree(file);
722 return(err);
723 }
724
725 int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
726 {
727 char *file;
728 int err;
729
730 if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM);
731 err = do_rmdir(file);
732 kfree(file);
733 return(err);
734 }
735
736 int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
737 {
738 struct inode *inode;
739 char *name;
740 int err = -ENOMEM;
741
742 inode = iget(dir->i_sb, 0);
743 if(inode == NULL)
744 goto out;
745
746 err = init_inode(inode, dentry);
747 if(err)
748 goto out_put;
749
750 err = -ENOMEM;
751 name = dentry_name(dentry, 0);
752 if(name == NULL)
753 goto out_put;
754
755 init_special_inode(inode, mode, dev);
756 err = do_mknod(name, mode, dev);
757 if(err)
758 goto out_free;
759
760 err = read_name(inode, name);
761 kfree(name);
762 if(err)
763 goto out_put;
764
765 d_instantiate(dentry, inode);
766 return(0);
767
768 out_free:
769 kfree(name);
770 out_put:
771 iput(inode);
772 out:
773 return(err);
774 }
775
776 int hostfs_rename(struct inode *from_ino, struct dentry *from,
777 struct inode *to_ino, struct dentry *to)
778 {
779 char *from_name, *to_name;
780 int err;
781
782 if((from_name = inode_dentry_name(from_ino, from)) == NULL)
783 return(-ENOMEM);
784 if((to_name = inode_dentry_name(to_ino, to)) == NULL){
785 kfree(from_name);
786 return(-ENOMEM);
787 }
788 err = rename_file(from_name, to_name);
789 kfree(from_name);
790 kfree(to_name);
791 return(err);
792 }
793
794 void hostfs_truncate(struct inode *ino)
795 {
796 not_implemented();
797 }
798
799 int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd)
800 {
801 char *name;
802 int r = 0, w = 0, x = 0, err;
803
804 if(desired & MAY_READ) r = 1;
805 if(desired & MAY_WRITE) w = 1;
806 if(desired & MAY_EXEC) x = 1;
807 name = inode_name(ino, 0);
808 if(name == NULL) return(-ENOMEM);
809 err = access_file(name, r, w, x);
810 kfree(name);
811 if(!err) err = vfs_permission(ino, desired);
812 return(err);
813 }
814
815 int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
816 {
817 struct hostfs_iattr attrs;
818 char *name;
819 int err;
820
821 if(append)
822 attr->ia_valid &= ~ATTR_SIZE;
823
824 attrs.ia_valid = 0;
825 if(attr->ia_valid & ATTR_MODE){
826 attrs.ia_valid |= HOSTFS_ATTR_MODE;
827 attrs.ia_mode = attr->ia_mode;
828 }
829 if(attr->ia_valid & ATTR_UID){
830 if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
831 (attr->ia_uid == 0))
832 attr->ia_uid = getuid();
833 attrs.ia_valid |= HOSTFS_ATTR_UID;
834 attrs.ia_uid = attr->ia_uid;
835 }
836 if(attr->ia_valid & ATTR_GID){
837 if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
838 (attr->ia_gid == 0))
839 attr->ia_gid = getuid();
840 attrs.ia_valid |= HOSTFS_ATTR_GID;
841 attrs.ia_gid = attr->ia_gid;
842 }
843 if(attr->ia_valid & ATTR_SIZE){
844 attrs.ia_valid |= HOSTFS_ATTR_SIZE;
845 attrs.ia_size = attr->ia_size;
846 }
847 if(attr->ia_valid & ATTR_ATIME){
848 attrs.ia_valid |= HOSTFS_ATTR_ATIME;
849 attrs.ia_atime = attr->ia_atime;
850 }
851 if(attr->ia_valid & ATTR_MTIME){
852 attrs.ia_valid |= HOSTFS_ATTR_MTIME;
853 attrs.ia_mtime = attr->ia_mtime;
854 }
855 if(attr->ia_valid & ATTR_CTIME){
856 attrs.ia_valid |= HOSTFS_ATTR_CTIME;
857 attrs.ia_ctime = attr->ia_ctime;
858 }
859 if(attr->ia_valid & ATTR_ATIME_SET){
860 attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET;
861 }
862 if(attr->ia_valid & ATTR_MTIME_SET){
863 attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET;
864 }
865 name = dentry_name(dentry, 0);
866 if(name == NULL) return(-ENOMEM);
867 err = set_attr(name, &attrs);
868 kfree(name);
869 if(err)
870 return(err);
871
872 return(inode_setattr(dentry->d_inode, attr));
873 }
874
875 int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
876 struct kstat *stat)
877 {
878 generic_fillattr(dentry->d_inode, stat);
879 return(0);
880 }
881
882 static struct inode_operations hostfs_iops = {
883 .create = hostfs_create,
884 .link = hostfs_link,
885 .unlink = hostfs_unlink,
886 .symlink = hostfs_symlink,
887 .mkdir = hostfs_mkdir,
888 .rmdir = hostfs_rmdir,
889 .mknod = hostfs_mknod,
890 .rename = hostfs_rename,
891 .truncate = hostfs_truncate,
892 .permission = hostfs_permission,
893 .setattr = hostfs_setattr,
894 .getattr = hostfs_getattr,
895 };
896
897 static struct inode_operations hostfs_dir_iops = {
898 .create = hostfs_create,
899 .lookup = hostfs_lookup,
900 .link = hostfs_link,
901 .unlink = hostfs_unlink,
902 .symlink = hostfs_symlink,
903 .mkdir = hostfs_mkdir,
904 .rmdir = hostfs_rmdir,
905 .mknod = hostfs_mknod,
906 .rename = hostfs_rename,
907 .truncate = hostfs_truncate,
908 .permission = hostfs_permission,
909 .setattr = hostfs_setattr,
910 .getattr = hostfs_getattr,
911 };
912
913 int hostfs_link_readpage(struct file *file, struct page *page)
914 {
915 char *buffer, *name;
916 long long start;
917 int err;
918
919 start = page->index << PAGE_CACHE_SHIFT;
920 buffer = kmap(page);
921 name = inode_name(page->mapping->host, 0);
922 if(name == NULL) return(-ENOMEM);
923 err = do_readlink(name, buffer, PAGE_CACHE_SIZE);
924 kfree(name);
925 if(err == PAGE_CACHE_SIZE)
926 err = -E2BIG;
927 else if(err > 0){
928 flush_dcache_page(page);
929 SetPageUptodate(page);
930 if (PageError(page)) ClearPageError(page);
931 err = 0;
932 }
933 kunmap(page);
934 unlock_page(page);
935 return(err);
936 }
937
938 static struct address_space_operations hostfs_link_aops = {
939 .readpage = hostfs_link_readpage,
940 };
941
942 static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
943 {
944 struct inode *root_inode;
945 char *name, *data = d;
946 int err;
947
948 sb->s_blocksize = 1024;
949 sb->s_blocksize_bits = 10;
950 sb->s_magic = HOSTFS_SUPER_MAGIC;
951 sb->s_op = &hostfs_sbops;
952
953 if((data == NULL) || (*data == '\0'))
954 data = root_ino;
955
956 err = -ENOMEM;
957 name = kmalloc(strlen(data) + 1, GFP_KERNEL);
958 if(name == NULL)
959 goto out;
960
961 strcpy(name, data);
962
963 root_inode = iget(sb, 0);
964 if(root_inode == NULL)
965 goto out_free;
966
967 err = init_inode(root_inode, NULL);
968 if(err)
969 goto out_put;
970
971 HOSTFS_I(root_inode)->host_filename = name;
972
973 err = -ENOMEM;
974 sb->s_root = d_alloc_root(root_inode);
975 if(sb->s_root == NULL)
976 goto out_put;
977
978 err = read_inode(root_inode);
979 if(err)
980 goto out_put;
981
982 return(0);
983
984 out_put:
985 iput(root_inode);
986 out_free:
987 kfree(name);
988 out:
989 return(err);
990 }
991
992 static struct super_block *hostfs_read_sb(struct file_system_type *type,
993 int flags, const char *dev_name,
994 void *data)
995 {
996 return(get_sb_nodev(type, flags, data, hostfs_fill_sb_common));
997 }
998
999 static struct file_system_type hostfs_type = {
1000 .owner = THIS_MODULE,
1001 .name = "hostfs",
1002 .get_sb = hostfs_read_sb,
1003 .kill_sb = kill_anon_super,
1004 .fs_flags = 0,
1005 };
1006
1007 static int __init init_hostfs(void)
1008 {
1009 return(register_filesystem(&hostfs_type));
1010 }
1011
1012 static void __exit exit_hostfs(void)
1013 {
1014 unregister_filesystem(&hostfs_type);
1015 }
1016
1017 module_init(init_hostfs)
1018 module_exit(exit_hostfs)
1019 MODULE_LICENSE("GPL");
1020
1021 /*
1022 * Overrides for Emacs so that we follow Linus's tabbing style.
1023 * Emacs will notice this stuff at the end of the file and automatically
1024 * adjust the settings for this buffer only. This must remain at the end
1025 * of the file.
1026 * ---------------------------------------------------------------------------
1027 * Local variables:
1028 * c-file-style: "linux"
1029 * End:
1030 */
MOXA 2.6.9 from sdlinux-moxaart.tgz