xref: /linux/fs/hpfs/super.c (revision 663a917475530feff868a4f2bda286ea4171f420)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/hpfs/super.c
4  *
5  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6  *
7  *  mounting, unmounting, error handling
8  */
9 
10 #include "hpfs_fn.h"
11 #include <linux/module.h>
12 #include <linux/fs_context.h>
13 #include <linux/fs_parser.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/magic.h>
17 #include <linux/sched.h>
18 #include <linux/bitmap.h>
19 #include <linux/slab.h>
20 #include <linux/seq_file.h>
21 
22 /* Mark the filesystem dirty, so that chkdsk checks it when os/2 booted */
23 
24 static void mark_dirty(struct super_block *s, int remount)
25 {
26 	if (hpfs_sb(s)->sb_chkdsk && (remount || !sb_rdonly(s))) {
27 		struct buffer_head *bh;
28 		struct hpfs_spare_block *sb;
29 		if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
30 			sb->dirty = 1;
31 			sb->old_wrote = 0;
32 			mark_buffer_dirty(bh);
33 			sync_dirty_buffer(bh);
34 			brelse(bh);
35 		}
36 	}
37 }
38 
39 /* Mark the filesystem clean (mark it dirty for chkdsk if chkdsk==2 or if there
40    were errors) */
41 
42 static void unmark_dirty(struct super_block *s)
43 {
44 	struct buffer_head *bh;
45 	struct hpfs_spare_block *sb;
46 	if (sb_rdonly(s)) return;
47 	sync_blockdev(s->s_bdev);
48 	if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
49 		sb->dirty = hpfs_sb(s)->sb_chkdsk > 1 - hpfs_sb(s)->sb_was_error;
50 		sb->old_wrote = hpfs_sb(s)->sb_chkdsk >= 2 && !hpfs_sb(s)->sb_was_error;
51 		mark_buffer_dirty(bh);
52 		sync_dirty_buffer(bh);
53 		brelse(bh);
54 	}
55 }
56 
57 /* Filesystem error... */
58 void hpfs_error(struct super_block *s, const char *fmt, ...)
59 {
60 	struct va_format vaf;
61 	va_list args;
62 
63 	va_start(args, fmt);
64 
65 	vaf.fmt = fmt;
66 	vaf.va = &args;
67 
68 	pr_err("filesystem error: %pV", &vaf);
69 
70 	va_end(args);
71 
72 	if (!hpfs_sb(s)->sb_was_error) {
73 		if (hpfs_sb(s)->sb_err == 2) {
74 			pr_cont("; crashing the system because you wanted it\n");
75 			mark_dirty(s, 0);
76 			panic("HPFS panic");
77 		} else if (hpfs_sb(s)->sb_err == 1) {
78 			if (sb_rdonly(s))
79 				pr_cont("; already mounted read-only\n");
80 			else {
81 				pr_cont("; remounting read-only\n");
82 				mark_dirty(s, 0);
83 				s->s_flags |= SB_RDONLY;
84 			}
85 		} else if (sb_rdonly(s))
86 				pr_cont("; going on - but anything won't be destroyed because it's read-only\n");
87 		else
88 			pr_cont("; corrupted filesystem mounted read/write - your computer will explode within 20 seconds ... but you wanted it so!\n");
89 	} else
90 		pr_cont("\n");
91 	hpfs_sb(s)->sb_was_error = 1;
92 }
93 
94 /*
95  * A little trick to detect cycles in many hpfs structures and don't let the
96  * kernel crash on corrupted filesystem. When first called, set c2 to 0.
97  *
98  * BTW. chkdsk doesn't detect cycles correctly. When I had 2 lost directories
99  * nested each in other, chkdsk locked up happilly.
100  */
101 
102 int hpfs_stop_cycles(struct super_block *s, int key, int *c1, int *c2,
103 		char *msg)
104 {
105 	if (*c2 && *c1 == key) {
106 		hpfs_error(s, "cycle detected on key %08x in %s", key, msg);
107 		return 1;
108 	}
109 	(*c2)++;
110 	if (!((*c2 - 1) & *c2)) *c1 = key;
111 	return 0;
112 }
113 
114 static void free_sbi(struct hpfs_sb_info *sbi)
115 {
116 	kfree(sbi->sb_cp_table);
117 	kfree(sbi->sb_bmp_dir);
118 	kfree(sbi);
119 }
120 
121 static void lazy_free_sbi(struct rcu_head *rcu)
122 {
123 	free_sbi(container_of(rcu, struct hpfs_sb_info, rcu));
124 }
125 
126 static void hpfs_put_super(struct super_block *s)
127 {
128 	hpfs_lock(s);
129 	unmark_dirty(s);
130 	hpfs_unlock(s);
131 	call_rcu(&hpfs_sb(s)->rcu, lazy_free_sbi);
132 }
133 
134 static unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
135 {
136 	struct quad_buffer_head qbh;
137 	unsigned long *bits;
138 	unsigned count;
139 
140 	bits = hpfs_map_4sectors(s, secno, &qbh, 0);
141 	if (!bits)
142 		return (unsigned)-1;
143 	count = bitmap_weight(bits, 2048 * BITS_PER_BYTE);
144 	hpfs_brelse4(&qbh);
145 	return count;
146 }
147 
148 static unsigned count_bitmaps(struct super_block *s)
149 {
150 	unsigned n, count, n_bands;
151 	n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
152 	count = 0;
153 	for (n = 0; n < COUNT_RD_AHEAD; n++) {
154 		hpfs_prefetch_bitmap(s, n);
155 	}
156 	for (n = 0; n < n_bands; n++) {
157 		unsigned c;
158 		hpfs_prefetch_bitmap(s, n + COUNT_RD_AHEAD);
159 		c = hpfs_count_one_bitmap(s, le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[n]));
160 		if (c != (unsigned)-1)
161 			count += c;
162 	}
163 	return count;
164 }
165 
166 unsigned hpfs_get_free_dnodes(struct super_block *s)
167 {
168 	struct hpfs_sb_info *sbi = hpfs_sb(s);
169 	if (sbi->sb_n_free_dnodes == (unsigned)-1) {
170 		unsigned c = hpfs_count_one_bitmap(s, sbi->sb_dmap);
171 		if (c == (unsigned)-1)
172 			return 0;
173 		sbi->sb_n_free_dnodes = c;
174 	}
175 	return sbi->sb_n_free_dnodes;
176 }
177 
178 static int hpfs_statfs(struct dentry *dentry, struct kstatfs *buf)
179 {
180 	struct super_block *s = dentry->d_sb;
181 	struct hpfs_sb_info *sbi = hpfs_sb(s);
182 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
183 
184 	hpfs_lock(s);
185 
186 	if (sbi->sb_n_free == (unsigned)-1)
187 		sbi->sb_n_free = count_bitmaps(s);
188 
189 	buf->f_type = s->s_magic;
190 	buf->f_bsize = 512;
191 	buf->f_blocks = sbi->sb_fs_size;
192 	buf->f_bfree = sbi->sb_n_free;
193 	buf->f_bavail = sbi->sb_n_free;
194 	buf->f_files = sbi->sb_dirband_size / 4;
195 	buf->f_ffree = hpfs_get_free_dnodes(s);
196 	buf->f_fsid = u64_to_fsid(id);
197 	buf->f_namelen = 254;
198 
199 	hpfs_unlock(s);
200 
201 	return 0;
202 }
203 
204 
205 long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
206 {
207 	switch (cmd) {
208 		case FITRIM: {
209 			struct fstrim_range range;
210 			secno n_trimmed;
211 			int r;
212 			if (!capable(CAP_SYS_ADMIN))
213 				return -EPERM;
214 			if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
215 				return -EFAULT;
216 			r = hpfs_trim_fs(file_inode(file)->i_sb, range.start >> 9, (range.start + range.len) >> 9, (range.minlen + 511) >> 9, &n_trimmed);
217 			if (r)
218 				return r;
219 			range.len = (u64)n_trimmed << 9;
220 			if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
221 				return -EFAULT;
222 			return 0;
223 		}
224 		default: {
225 			return -ENOIOCTLCMD;
226 		}
227 	}
228 }
229 
230 
231 static struct kmem_cache * hpfs_inode_cachep;
232 
233 static struct inode *hpfs_alloc_inode(struct super_block *sb)
234 {
235 	struct hpfs_inode_info *ei;
236 	ei = alloc_inode_sb(sb, hpfs_inode_cachep, GFP_NOFS);
237 	if (!ei)
238 		return NULL;
239 	return &ei->vfs_inode;
240 }
241 
242 static void hpfs_free_inode(struct inode *inode)
243 {
244 	kmem_cache_free(hpfs_inode_cachep, hpfs_i(inode));
245 }
246 
247 static void init_once(void *foo)
248 {
249 	struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo;
250 
251 	inode_init_once(&ei->vfs_inode);
252 }
253 
254 static int init_inodecache(void)
255 {
256 	hpfs_inode_cachep = kmem_cache_create("hpfs_inode_cache",
257 					     sizeof(struct hpfs_inode_info),
258 					     0, (SLAB_RECLAIM_ACCOUNT|
259 						SLAB_ACCOUNT),
260 					     init_once);
261 	if (hpfs_inode_cachep == NULL)
262 		return -ENOMEM;
263 	return 0;
264 }
265 
266 static void destroy_inodecache(void)
267 {
268 	/*
269 	 * Make sure all delayed rcu free inodes are flushed before we
270 	 * destroy cache.
271 	 */
272 	rcu_barrier();
273 	kmem_cache_destroy(hpfs_inode_cachep);
274 }
275 
276 enum {
277 	Opt_help, Opt_uid, Opt_gid, Opt_umask, Opt_case,
278 	Opt_check, Opt_err, Opt_eas, Opt_chkdsk, Opt_timeshift,
279 };
280 
281 static const struct constant_table hpfs_param_case[] = {
282 	{"asis",	0},
283 	{"lower",	1},
284 	{}
285 };
286 
287 static const struct constant_table hpfs_param_check[] = {
288 	{"none",	0},
289 	{"normal",	1},
290 	{"strict",	2},
291 	{}
292 };
293 
294 static const struct constant_table hpfs_param_err[] = {
295 	{"continue",	0},
296 	{"remount-ro",	1},
297 	{"panic",	2},
298 	{}
299 };
300 
301 static const struct constant_table hpfs_param_eas[] = {
302 	{"no",		0},
303 	{"ro",		1},
304 	{"rw",		2},
305 	{}
306 };
307 
308 static const struct constant_table hpfs_param_chkdsk[] = {
309 	{"no",		0},
310 	{"errors",	1},
311 	{"always",	2},
312 	{}
313 };
314 
315 static const struct fs_parameter_spec hpfs_param_spec[] = {
316 	fsparam_flag	("help",	Opt_help),
317 	fsparam_uid	("uid",		Opt_uid),
318 	fsparam_gid	("gid",		Opt_gid),
319 	fsparam_u32oct	("umask",	Opt_umask),
320 	fsparam_enum	("case",	Opt_case,	hpfs_param_case),
321 	fsparam_enum	("check",	Opt_check,	hpfs_param_check),
322 	fsparam_enum	("errors",	Opt_err,	hpfs_param_err),
323 	fsparam_enum	("eas",		Opt_eas,	hpfs_param_eas),
324 	fsparam_enum	("chkdsk",	Opt_chkdsk,	hpfs_param_chkdsk),
325 	fsparam_s32	("timeshift",	Opt_timeshift),
326 	{}
327 };
328 
329 struct hpfs_fc_context {
330 	kuid_t uid;
331 	kgid_t gid;
332 	umode_t umask;
333 	int lowercase;
334 	int eas;
335 	int chk;
336 	int errs;
337 	int chkdsk;
338 	int timeshift;
339 };
340 
341 static inline void hpfs_help(void)
342 {
343 	pr_info("\n\
344 HPFS filesystem options:\n\
345       help              do not mount and display this text\n\
346       uid=xxx           set uid of files that don't have uid specified in eas\n\
347       gid=xxx           set gid of files that don't have gid specified in eas\n\
348       umask=xxx         set mode of files that don't have mode specified in eas\n\
349       case=lower        lowercase all files\n\
350       case=asis         do not lowercase files (default)\n\
351       check=none        no fs checks - kernel may crash on corrupted filesystem\n\
352       check=normal      do some checks - it should not crash (default)\n\
353       check=strict      do extra time-consuming checks, used for debugging\n\
354       errors=continue   continue on errors\n\
355       errors=remount-ro remount read-only if errors found (default)\n\
356       errors=panic      panic on errors\n\
357       chkdsk=no         do not mark fs for chkdsking even if there were errors\n\
358       chkdsk=errors     mark fs dirty if errors found (default)\n\
359       chkdsk=always     always mark fs dirty - used for debugging\n\
360       eas=no            ignore extended attributes\n\
361       eas=ro            read but do not write extended attributes\n\
362       eas=rw            r/w eas => enables chmod, chown, mknod, ln -s (default)\n\
363       timeshift=nnn	add nnn seconds to file times\n\
364 \n");
365 }
366 
367 static int hpfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
368 {
369 	struct hpfs_fc_context *ctx = fc->fs_private;
370 	struct fs_parse_result result;
371 	int opt;
372 
373 	opt = fs_parse(fc, hpfs_param_spec, param, &result);
374 	if (opt < 0)
375 		return opt;
376 
377 	switch (opt) {
378 	case Opt_help:
379 		hpfs_help();
380 		return -EINVAL;
381 	case Opt_uid:
382 		ctx->uid = result.uid;
383 		break;
384 	case Opt_gid:
385 		ctx->gid = result.gid;
386 		break;
387 	case Opt_umask:
388 		ctx->umask = result.uint_32;
389 		break;
390 	case Opt_case:
391 		ctx->lowercase = result.uint_32;
392 		break;
393 	case Opt_check:
394 		ctx->chk = result.uint_32;
395 		break;
396 	case Opt_err:
397 		ctx->errs = result.uint_32;
398 		break;
399 	case Opt_eas:
400 		ctx->eas = result.uint_32;
401 		break;
402 	case Opt_chkdsk:
403 		ctx->chkdsk = result.uint_32;
404 		break;
405 	case Opt_timeshift:
406 		{
407 			int m = 1;
408 			char *rhs = param->string;
409 			int timeshift;
410 
411 			if (*rhs == '-') m = -1;
412 			if (*rhs == '+' || *rhs == '-') rhs++;
413 			timeshift = simple_strtoul(rhs, &rhs, 0) * m;
414 			if (*rhs)
415 					return -EINVAL;
416 			ctx->timeshift = timeshift;
417 			break;
418 		}
419 	default:
420 		return -EINVAL;
421 	}
422 
423 	return 0;
424 }
425 
426 static int hpfs_reconfigure(struct fs_context *fc)
427 {
428 	struct hpfs_fc_context *ctx = fc->fs_private;
429 	struct super_block *s = fc->root->d_sb;
430 	struct hpfs_sb_info *sbi = hpfs_sb(s);
431 
432 	sync_filesystem(s);
433 
434 	fc->sb_flags |= SB_NOATIME;
435 
436 	hpfs_lock(s);
437 
438 	if (ctx->timeshift != sbi->sb_timeshift) {
439 		pr_err("timeshift can't be changed using remount.\n");
440 		goto out_err;
441 	}
442 
443 	unmark_dirty(s);
444 
445 	sbi->sb_uid = ctx->uid; sbi->sb_gid = ctx->gid;
446 	sbi->sb_mode = 0777 & ~ctx->umask;
447 	sbi->sb_lowercase = ctx->lowercase;
448 	sbi->sb_eas = ctx->eas; sbi->sb_chk = ctx->chk;
449 	sbi->sb_chkdsk = ctx->chkdsk;
450 	sbi->sb_err = ctx->errs; sbi->sb_timeshift = ctx->timeshift;
451 
452 	if (!(fc->sb_flags & SB_RDONLY)) mark_dirty(s, 1);
453 
454 	hpfs_unlock(s);
455 	return 0;
456 
457 out_err:
458 	hpfs_unlock(s);
459 	return -EINVAL;
460 }
461 
462 static int hpfs_show_options(struct seq_file *seq, struct dentry *root)
463 {
464 	struct hpfs_sb_info *sbi = hpfs_sb(root->d_sb);
465 
466 	seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, sbi->sb_uid));
467 	seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, sbi->sb_gid));
468 	seq_printf(seq, ",umask=%03o", (~sbi->sb_mode & 0777));
469 	if (sbi->sb_lowercase)
470 		seq_printf(seq, ",case=lower");
471 	if (!sbi->sb_chk)
472 		seq_printf(seq, ",check=none");
473 	if (sbi->sb_chk == 2)
474 		seq_printf(seq, ",check=strict");
475 	if (!sbi->sb_err)
476 		seq_printf(seq, ",errors=continue");
477 	if (sbi->sb_err == 2)
478 		seq_printf(seq, ",errors=panic");
479 	if (!sbi->sb_chkdsk)
480 		seq_printf(seq, ",chkdsk=no");
481 	if (sbi->sb_chkdsk == 2)
482 		seq_printf(seq, ",chkdsk=always");
483 	if (!sbi->sb_eas)
484 		seq_printf(seq, ",eas=no");
485 	if (sbi->sb_eas == 1)
486 		seq_printf(seq, ",eas=ro");
487 	if (sbi->sb_timeshift)
488 		seq_printf(seq, ",timeshift=%d", sbi->sb_timeshift);
489 	return 0;
490 }
491 
492 /* Super operations */
493 
494 static const struct super_operations hpfs_sops =
495 {
496 	.alloc_inode	= hpfs_alloc_inode,
497 	.free_inode	= hpfs_free_inode,
498 	.evict_inode	= hpfs_evict_inode,
499 	.put_super	= hpfs_put_super,
500 	.statfs		= hpfs_statfs,
501 	.show_options	= hpfs_show_options,
502 };
503 
504 static int hpfs_fill_super(struct super_block *s, struct fs_context *fc)
505 {
506 	struct hpfs_fc_context *ctx = fc->fs_private;
507 	struct buffer_head *bh0, *bh1, *bh2;
508 	struct hpfs_boot_block *bootblock;
509 	struct hpfs_super_block *superblock;
510 	struct hpfs_spare_block *spareblock;
511 	struct hpfs_sb_info *sbi;
512 	struct inode *root;
513 	int silent = fc->sb_flags & SB_SILENT;
514 
515 	dnode_secno root_dno;
516 	struct hpfs_dirent *de = NULL;
517 	struct quad_buffer_head qbh;
518 
519 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
520 	if (!sbi) {
521 		return -ENOMEM;
522 	}
523 	s->s_fs_info = sbi;
524 
525 	mutex_init(&sbi->hpfs_mutex);
526 	hpfs_lock(s);
527 
528 	/*sbi->sb_mounting = 1;*/
529 	sb_set_blocksize(s, 512);
530 	sbi->sb_fs_size = -1;
531 	if (!(bootblock = hpfs_map_sector(s, 0, &bh0, 0))) goto bail1;
532 	if (!(superblock = hpfs_map_sector(s, 16, &bh1, 1))) goto bail2;
533 	if (!(spareblock = hpfs_map_sector(s, 17, &bh2, 0))) goto bail3;
534 
535 	/* Check magics */
536 	if (/*le16_to_cpu(bootblock->magic) != BB_MAGIC
537 	    ||*/ le32_to_cpu(superblock->magic) != SB_MAGIC
538 	    || le32_to_cpu(spareblock->magic) != SP_MAGIC) {
539 		if (!silent)
540 			pr_err("Bad magic ... probably not HPFS\n");
541 		goto bail4;
542 	}
543 
544 	/* Check version */
545 	if (!sb_rdonly(s) && superblock->funcversion != 2 && superblock->funcversion != 3) {
546 		pr_err("Bad version %d,%d. Mount readonly to go around\n",
547 			(int)superblock->version, (int)superblock->funcversion);
548 		pr_err("please try recent version of HPFS driver at http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi and if it still can't understand this format, contact author - mikulas@artax.karlin.mff.cuni.cz\n");
549 		goto bail4;
550 	}
551 
552 	s->s_flags |= SB_NOATIME;
553 
554 	/* Fill superblock stuff */
555 	s->s_magic = HPFS_SUPER_MAGIC;
556 	s->s_op = &hpfs_sops;
557 	s->s_d_op = &hpfs_dentry_operations;
558 	s->s_time_min =  local_to_gmt(s, 0);
559 	s->s_time_max =  local_to_gmt(s, U32_MAX);
560 
561 	sbi->sb_root = le32_to_cpu(superblock->root);
562 	sbi->sb_fs_size = le32_to_cpu(superblock->n_sectors);
563 	sbi->sb_bitmaps = le32_to_cpu(superblock->bitmaps);
564 	sbi->sb_dirband_start = le32_to_cpu(superblock->dir_band_start);
565 	sbi->sb_dirband_size = le32_to_cpu(superblock->n_dir_band);
566 	sbi->sb_dmap = le32_to_cpu(superblock->dir_band_bitmap);
567 	sbi->sb_uid = ctx->uid;
568 	sbi->sb_gid = ctx->gid;
569 	sbi->sb_mode = 0777 & ~ctx->umask;
570 	sbi->sb_n_free = -1;
571 	sbi->sb_n_free_dnodes = -1;
572 	sbi->sb_lowercase = ctx->lowercase;
573 	sbi->sb_eas = ctx->eas;
574 	sbi->sb_chk = ctx->chk;
575 	sbi->sb_chkdsk = ctx->chkdsk;
576 	sbi->sb_err = ctx->errs;
577 	sbi->sb_timeshift = ctx->timeshift;
578 	sbi->sb_was_error = 0;
579 	sbi->sb_cp_table = NULL;
580 	sbi->sb_c_bitmap = -1;
581 	sbi->sb_max_fwd_alloc = 0xffffff;
582 
583 	if (sbi->sb_fs_size >= 0x80000000) {
584 		hpfs_error(s, "invalid size in superblock: %08x",
585 			(unsigned)sbi->sb_fs_size);
586 		goto bail4;
587 	}
588 
589 	if (spareblock->n_spares_used)
590 		hpfs_load_hotfix_map(s, spareblock);
591 
592 	/* Load bitmap directory */
593 	if (!(sbi->sb_bmp_dir = hpfs_load_bitmap_directory(s, le32_to_cpu(superblock->bitmaps))))
594 		goto bail4;
595 
596 	/* Check for general fs errors*/
597 	if (spareblock->dirty && !spareblock->old_wrote) {
598 		if (sbi->sb_err == 2) {
599 			pr_err("Improperly stopped, not mounted\n");
600 			goto bail4;
601 		}
602 		hpfs_error(s, "improperly stopped");
603 	}
604 
605 	if (!sb_rdonly(s)) {
606 		spareblock->dirty = 1;
607 		spareblock->old_wrote = 0;
608 		mark_buffer_dirty(bh2);
609 	}
610 
611 	if (le32_to_cpu(spareblock->n_dnode_spares) != le32_to_cpu(spareblock->n_dnode_spares_free)) {
612 		if (sbi->sb_err >= 2) {
613 			pr_err("Spare dnodes used, try chkdsk\n");
614 			mark_dirty(s, 0);
615 			goto bail4;
616 		}
617 		hpfs_error(s, "warning: spare dnodes used, try chkdsk");
618 		if (sbi->sb_err == 0)
619 			pr_err("Proceeding, but your filesystem could be corrupted if you delete files or directories\n");
620 	}
621 	if (sbi->sb_chk) {
622 		unsigned a;
623 		if (le32_to_cpu(superblock->dir_band_end) - le32_to_cpu(superblock->dir_band_start) + 1 != le32_to_cpu(superblock->n_dir_band) ||
624 		    le32_to_cpu(superblock->dir_band_end) < le32_to_cpu(superblock->dir_band_start) || le32_to_cpu(superblock->n_dir_band) > 0x4000) {
625 			hpfs_error(s, "dir band size mismatch: dir_band_start==%08x, dir_band_end==%08x, n_dir_band==%08x",
626 				le32_to_cpu(superblock->dir_band_start), le32_to_cpu(superblock->dir_band_end), le32_to_cpu(superblock->n_dir_band));
627 			goto bail4;
628 		}
629 		a = sbi->sb_dirband_size;
630 		sbi->sb_dirband_size = 0;
631 		if (hpfs_chk_sectors(s, le32_to_cpu(superblock->dir_band_start), le32_to_cpu(superblock->n_dir_band), "dir_band") ||
632 		    hpfs_chk_sectors(s, le32_to_cpu(superblock->dir_band_bitmap), 4, "dir_band_bitmap") ||
633 		    hpfs_chk_sectors(s, le32_to_cpu(superblock->bitmaps), 4, "bitmaps")) {
634 			mark_dirty(s, 0);
635 			goto bail4;
636 		}
637 		sbi->sb_dirband_size = a;
638 	} else
639 		pr_err("You really don't want any checks? You are crazy...\n");
640 
641 	/* Load code page table */
642 	if (le32_to_cpu(spareblock->n_code_pages))
643 		if (!(sbi->sb_cp_table = hpfs_load_code_page(s, le32_to_cpu(spareblock->code_page_dir))))
644 			pr_err("code page support is disabled\n");
645 
646 	brelse(bh2);
647 	brelse(bh1);
648 	brelse(bh0);
649 
650 	root = iget_locked(s, sbi->sb_root);
651 	if (!root)
652 		goto bail0;
653 	hpfs_init_inode(root);
654 	hpfs_read_inode(root);
655 	unlock_new_inode(root);
656 	s->s_root = d_make_root(root);
657 	if (!s->s_root)
658 		goto bail0;
659 
660 	/*
661 	 * find the root directory's . pointer & finish filling in the inode
662 	 */
663 
664 	root_dno = hpfs_fnode_dno(s, sbi->sb_root);
665 	if (root_dno)
666 		de = map_dirent(root, root_dno, "\001\001", 2, NULL, &qbh);
667 	if (!de)
668 		hpfs_error(s, "unable to find root dir");
669 	else {
670 		inode_set_atime(root,
671 				local_to_gmt(s, le32_to_cpu(de->read_date)),
672 				0);
673 		inode_set_mtime(root,
674 				local_to_gmt(s, le32_to_cpu(de->write_date)),
675 				0);
676 		inode_set_ctime(root,
677 				local_to_gmt(s, le32_to_cpu(de->creation_date)),
678 				0);
679 		hpfs_i(root)->i_ea_size = le32_to_cpu(de->ea_size);
680 		hpfs_i(root)->i_parent_dir = root->i_ino;
681 		if (root->i_size == -1)
682 			root->i_size = 2048;
683 		if (root->i_blocks == -1)
684 			root->i_blocks = 5;
685 		hpfs_brelse4(&qbh);
686 	}
687 	hpfs_unlock(s);
688 	return 0;
689 
690 bail4:	brelse(bh2);
691 bail3:	brelse(bh1);
692 bail2:	brelse(bh0);
693 bail1:
694 bail0:
695 	hpfs_unlock(s);
696 	free_sbi(sbi);
697 	return -EINVAL;
698 }
699 
700 static int hpfs_get_tree(struct fs_context *fc)
701 {
702 	return get_tree_bdev(fc, hpfs_fill_super);
703 }
704 
705 static void hpfs_free_fc(struct fs_context *fc)
706 {
707 	kfree(fc->fs_private);
708 }
709 
710 static const struct fs_context_operations hpfs_fc_context_ops = {
711 	.parse_param	= hpfs_parse_param,
712 	.get_tree	= hpfs_get_tree,
713 	.reconfigure	= hpfs_reconfigure,
714 	.free		= hpfs_free_fc,
715 };
716 
717 static int hpfs_init_fs_context(struct fs_context *fc)
718 {
719 	struct hpfs_fc_context *ctx;
720 
721 	ctx = kzalloc(sizeof(struct hpfs_fc_context), GFP_KERNEL);
722 	if (!ctx)
723 		return -ENOMEM;
724 
725 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
726 		struct super_block *sb = fc->root->d_sb;
727 		struct hpfs_sb_info *sbi = hpfs_sb(sb);
728 
729 		ctx->uid = sbi->sb_uid;
730 		ctx->gid = sbi->sb_gid;
731 		ctx->umask = 0777 & ~sbi->sb_mode;
732 		ctx->lowercase = sbi->sb_lowercase;
733 		ctx->eas = sbi->sb_eas;
734 		ctx->chk = sbi->sb_chk;
735 		ctx->chkdsk = sbi->sb_chkdsk;
736 		ctx->errs = sbi->sb_err;
737 		ctx->timeshift = sbi->sb_timeshift;
738 
739 	} else {
740 		ctx->uid = current_uid();
741 		ctx->gid = current_gid();
742 		ctx->umask = current_umask();
743 		ctx->lowercase = 0;
744 		ctx->eas = 2;
745 		ctx->chk = 1;
746 		ctx->errs = 1;
747 		ctx->chkdsk = 1;
748 		ctx->timeshift = 0;
749 	}
750 
751 	fc->fs_private = ctx;
752 	fc->ops = &hpfs_fc_context_ops;
753 
754 	return 0;
755 };
756 
757 static struct file_system_type hpfs_fs_type = {
758 	.owner		= THIS_MODULE,
759 	.name		= "hpfs",
760 	.kill_sb	= kill_block_super,
761 	.fs_flags	= FS_REQUIRES_DEV,
762 	.init_fs_context = hpfs_init_fs_context,
763 	.parameters	= hpfs_param_spec,
764 };
765 MODULE_ALIAS_FS("hpfs");
766 
767 static int __init init_hpfs_fs(void)
768 {
769 	int err = init_inodecache();
770 	if (err)
771 		goto out1;
772 	err = register_filesystem(&hpfs_fs_type);
773 	if (err)
774 		goto out;
775 	return 0;
776 out:
777 	destroy_inodecache();
778 out1:
779 	return err;
780 }
781 
782 static void __exit exit_hpfs_fs(void)
783 {
784 	unregister_filesystem(&hpfs_fs_type);
785 	destroy_inodecache();
786 }
787 
788 module_init(init_hpfs_fs)
789 module_exit(exit_hpfs_fs)
790 MODULE_DESCRIPTION("OS/2 HPFS file system support");
791 MODULE_LICENSE("GPL");
792