xref: /netbsd-src/sys/ufs/chfs/chfs_scan.c (revision 1897181a7231d5fc7ab48994d1447fcbc4e13a49)
1 /*	$NetBSD: chfs_scan.c,v 1.2 2011/11/24 21:09:37 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 2010 Department of Software Engineering,
5  *		      University of Szeged, Hungary
6  * Copyright (c) 2010 David Tengeri <dtengeri@inf.u-szeged.hu>
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by the Department of Software Engineering, University of Szeged, Hungary
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * chfs_scan.c
36  *
37  *  Created on: 2009.11.05.
38  *      Author: dtengeri
39  */
40 
41 #include "chfs.h"
42 
43 /**
44  * chfs_scan_make_vnode_cache - makes a new vnode cache during scan
45  * @chmp: CHFS main descriptor structure
46  * @vno: vnode identifier
47  * This function returns a vnode cache belonging to @vno.
48  */
49 struct chfs_vnode_cache *
50 chfs_scan_make_vnode_cache(struct chfs_mount *chmp, ino_t vno)
51 {
52 	struct chfs_vnode_cache *vc;
53 
54 	KASSERT(mutex_owned(&chmp->chm_lock_vnocache));
55 
56 	vc = chfs_vnode_cache_get(chmp, vno);
57 	if (vc) {
58 		return vc;
59 	}
60 
61 	if (vno > chmp->chm_max_vno) {
62 		chmp->chm_max_vno = vno;
63 	}
64 
65 	vc = chfs_vnode_cache_alloc(vno);
66 
67 	//mutex_enter(&chmp->chm_lock_vnocache);
68 
69 	chfs_vnode_cache_add(chmp, vc);
70 
71 	//mutex_exit(&chmp->chm_lock_vnocache);
72 
73 	if (vno == CHFS_ROOTINO) {
74 		vc->nlink = 2;
75 		vc->pvno = CHFS_ROOTINO;
76 		chfs_vnode_cache_set_state(chmp,
77 		    vc, VNO_STATE_CHECKEDABSENT);
78 	}
79 
80 	return vc;
81 }
82 
83 /**
84  * chfs_scan_check_node_hdr - checks node magic and crc
85  * @nhdr: node header to check
86  * Returns 0 if everything is OK, error code otherwise.
87  */
88 int
89 chfs_scan_check_node_hdr(struct chfs_flash_node_hdr *nhdr)
90 {
91 	uint16_t magic;
92 	uint32_t crc, hdr_crc;
93 
94 	magic = le16toh(nhdr->magic);
95 
96 	if (magic != CHFS_FS_MAGIC_BITMASK) {
97 		dbg("bad magic\n");
98 		return CHFS_NODE_BADMAGIC;
99 	}
100 
101 	hdr_crc = le32toh(nhdr->hdr_crc);
102 	crc = crc32(0, (uint8_t *)nhdr, CHFS_NODE_HDR_SIZE - 4);
103 
104 	if (crc != hdr_crc) {
105 		dbg("bad crc\n");
106 		return CHFS_NODE_BADCRC;
107 	}
108 
109 	return CHFS_NODE_OK;
110 }
111 
112 /**
113  * chfs_scan_check_vnode - check vnode crc and add to vnode cache
114  * @chmp: CHFS main descriptor structure
115  * @cheb: eraseblock informations
116  * @buf: vnode to check
117  * @ofs: offset in eraseblock where vnode starts
118  */
119 int
120 chfs_scan_check_vnode(struct chfs_mount *chmp,
121     struct chfs_eraseblock *cheb, void *buf, off_t ofs)
122 {
123 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
124 	struct chfs_vnode_cache *vc;
125 	struct chfs_flash_vnode *vnode = buf;
126 	struct chfs_node_ref *nref;
127 	int err;
128 	uint32_t crc;
129 	ino_t vno;
130 
131 	crc = crc32(0, (uint8_t *)vnode,
132 	    sizeof(struct chfs_flash_vnode) - 4);
133 
134 	if (crc != le32toh(vnode->node_crc)) {
135 		err = chfs_update_eb_dirty(chmp,
136 		    cheb, le32toh(vnode->length));
137 		if (err) {
138 			return err;
139 		}
140 
141 		return CHFS_NODE_BADCRC;
142 	}
143 
144 	vno = le64toh(vnode->vno);
145 
146 	mutex_enter(&chmp->chm_lock_vnocache);
147 	vc = chfs_vnode_cache_get(chmp, vno);
148 	if (!vc) {
149 		vc = chfs_scan_make_vnode_cache(chmp, vno);
150 		if (!vc) {
151 			mutex_exit(&chmp->chm_lock_vnocache);
152 			return ENOMEM;
153 		}
154 	}
155 	mutex_exit(&chmp->chm_lock_vnocache);
156 
157 	nref = chfs_alloc_node_ref(cheb);
158 
159 	nref->nref_offset = ofs;
160 
161 	KASSERT(nref->nref_lnr == cheb->lnr);
162 
163 	/* Check version of vnode. */
164 	if ((struct chfs_vnode_cache *)vc->v != vc) {
165 		if (le64toh(vnode->version) > *vc->vno_version) {
166 			//err = chfs_update_eb_dirty(chmp, &chmp->chm_blocks[vc->v->lnr],
167 			//		sizeof(struct chfs_flash_vnode));
168 			*vc->vno_version = le64toh(vnode->version);
169 			chfs_add_vnode_ref_to_vc(chmp, vc, nref);
170 		} else {
171 			err = chfs_update_eb_dirty(chmp, cheb,
172 			    sizeof(struct chfs_flash_vnode));
173 			return CHFS_NODE_OK;
174 		}
175 	} else {
176 		vc->vno_version = kmem_alloc(sizeof(uint64_t), KM_SLEEP);
177 		if (!vc->vno_version)
178 			return ENOMEM;
179 		*vc->vno_version = le64toh(vnode->version);
180 		chfs_add_vnode_ref_to_vc(chmp, vc, nref);
181 	}
182 
183 	mutex_enter(&chmp->chm_lock_sizes);
184 	//dbg("B:lnr: %d |free_size: %d node's size: %d\n", cheb->lnr, cheb->free_size, le32toh(vnode->length));
185 	chfs_change_size_free(chmp, cheb, -le32toh(vnode->length));
186 	chfs_change_size_used(chmp, cheb, le32toh(vnode->length));
187 	mutex_exit(&chmp->chm_lock_sizes);
188 
189 	KASSERT(cheb->used_size <= chmp->chm_ebh->eb_size);
190 
191 	KASSERT(cheb->used_size + cheb->free_size + cheb->dirty_size + cheb->unchecked_size + cheb->wasted_size == chmp->chm_ebh->eb_size);
192 
193 	//dbg(" A: free_size: %d\n", cheb->free_size);
194 
195 	/*dbg("vnode dump:\n");
196 	  dbg(" ->magic:    0x%x\n", le16toh(vnode->magic));
197 	  dbg(" ->type:     %d\n", le16toh(vnode->type));
198 	  dbg(" ->length:   %d\n", le32toh(vnode->length));
199 	  dbg(" ->hdr_crc:  0x%x\n", le32toh(vnode->hdr_crc));
200 	  dbg(" ->vno:      %d\n", le64toh(vnode->vno));
201 	  dbg(" ->version:  %ld\n", le64toh(vnode->version));
202 	  dbg(" ->uid:      %d\n", le16toh(vnode->uid));
203 	  dbg(" ->gid:      %d\n", le16toh(vnode->gid));
204 	  dbg(" ->mode:     %d\n", le32toh(vnode->mode));
205 	  dbg(" ->dn_size:  %d\n", le32toh(vnode->dn_size));
206 	  dbg(" ->atime:    %d\n", le32toh(vnode->atime));
207 	  dbg(" ->mtime:    %d\n", le32toh(vnode->mtime));
208 	  dbg(" ->ctime:    %d\n", le32toh(vnode->ctime));
209 	  dbg(" ->dsize:    %d\n", le32toh(vnode->dsize));
210 	  dbg(" ->node_crc: 0x%x\n", le32toh(vnode->node_crc));*/
211 
212 	return CHFS_NODE_OK;
213 }
214 
215 int
216 chfs_scan_mark_dirent_obsolete(struct chfs_mount *chmp,
217     struct chfs_vnode_cache *vc, struct chfs_dirent *fd)
218 {
219 	//int size;
220 	struct chfs_eraseblock *cheb;
221 	struct chfs_node_ref *prev, *nref;
222 
223 	nref = fd->nref;
224 	cheb = &chmp->chm_blocks[fd->nref->nref_lnr];
225 
226 	/* Remove dirent's node ref from vnode cache */
227 	prev = vc->dirents;
228 	if (prev && prev == nref) {
229 		vc->dirents = prev->nref_next;
230 	} else if (prev && prev != (void *)vc) {
231 		while (prev->nref_next && prev->nref_next !=
232 		    (void *)vc && prev->nref_next != nref) {
233 			prev = prev->nref_next;
234 		}
235 
236 		if (prev->nref_next == nref) {
237 			prev->nref_next = nref->nref_next;
238 		}
239 	}
240 	/*dbg("XXX - start\n");
241 	//nref = vc->dirents;
242 	struct chfs_dirent *tmp;
243 	tmp = vc->scan_dirents;
244 	while (tmp) {
245 	dbg(" ->tmp->name:    %s\n", tmp->name);
246 	dbg(" ->tmp->version: %ld\n", tmp->version);
247 	dbg(" ->tmp->vno: %d\n", tmp->vno);
248 	tmp = tmp->next;
249 	}
250 	dbg("XXX - end\n");*/
251 	//size = CHFS_PAD(sizeof(struct chfs_flash_dirent_node) + fd->nsize);
252 
253 	KASSERT(cheb->used_size + cheb->free_size + cheb->dirty_size +
254 	    cheb->unchecked_size + cheb->wasted_size == chmp->chm_ebh->eb_size);
255 
256 	return 0;
257 }
258 
259 void
260 chfs_add_fd_to_list(struct chfs_mount *chmp,
261     struct chfs_dirent *new, struct chfs_vnode_cache *pvc)
262 {
263 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
264 	int size;
265 	struct chfs_eraseblock *cheb, *oldcheb;
266 //	struct chfs_dirent **prev;
267 	struct chfs_dirent *fd, *tmpfd;
268 
269 	dbg("adding fd to list: %s\n", new->name);
270 
271 	if ((new->version > pvc->highest_version))
272 		pvc->highest_version = new->version;
273 
274 	size = CHFS_PAD(sizeof(struct chfs_flash_dirent_node) +
275 	    new->nsize);
276 	cheb = &chmp->chm_blocks[new->nref->nref_lnr];
277 
278 	mutex_enter(&chmp->chm_lock_sizes);
279 	TAILQ_FOREACH_SAFE(fd, &pvc->scan_dirents, fds, tmpfd) {
280 		if (fd->nhash > new->nhash) {
281 			/* insert new before fd */
282 			TAILQ_INSERT_BEFORE(fd, new, fds);
283 			goto out;
284 		} else if (fd->nhash == new->nhash &&
285 		    !strcmp(fd->name, new->name)) {
286 			if (new->version > fd->version) {
287 //				new->next = fd->next;
288 				/* replace fd with new */
289 				TAILQ_INSERT_BEFORE(fd, new, fds);
290 				chfs_change_size_free(chmp, cheb, -size);
291 				chfs_change_size_used(chmp, cheb, size);
292 
293 				TAILQ_REMOVE(&pvc->scan_dirents, fd, fds);
294 				if (fd->nref) {
295 					size = CHFS_PAD(sizeof(struct chfs_flash_dirent_node) + fd->nsize);
296 					chfs_scan_mark_dirent_obsolete(chmp, pvc, fd);
297 					oldcheb = &chmp->chm_blocks[fd->nref->nref_lnr];
298 					chfs_change_size_used(chmp, oldcheb, -size);
299 					chfs_change_size_dirty(chmp, oldcheb, size);
300 				}
301 				chfs_free_dirent(fd);
302 //				*prev = new;//XXX
303 			} else {
304 				chfs_scan_mark_dirent_obsolete(chmp, pvc, new);
305 				chfs_change_size_free(chmp, cheb, -size);
306 				chfs_change_size_dirty(chmp, cheb, size);
307 				chfs_free_dirent(new);
308 			}
309 			/*dbg("START\n");
310 			  fd = pvc->scan_dirents;
311 			  while (fd) {
312 			  dbg("dirent dump:\n");
313 			  dbg(" ->vno:     %d\n", fd->vno);
314 			  dbg(" ->version: %ld\n", fd->version);
315 			  dbg(" ->nhash:   0x%x\n", fd->nhash);
316 			  dbg(" ->nsize:   %d\n", fd->nsize);
317 			  dbg(" ->name:    %s\n", fd->name);
318 			  dbg(" ->type:    %d\n", fd->type);
319 			  fd = fd->next;
320 			  }
321 			  dbg("END\n");*/
322 			mutex_exit(&chmp->chm_lock_sizes);
323 			return;
324 		}
325 	}
326 	/* if we couldnt fit it elsewhere, lets add to the end */
327 	TAILQ_INSERT_TAIL(&pvc->scan_dirents, new, fds);
328 
329 out:
330 	//dbg("B:lnr: %d |free_size: %d size: %d\n", cheb->lnr, cheb->free_size, size);
331 	chfs_change_size_free(chmp, cheb, -size);
332 	chfs_change_size_used(chmp, cheb, size);
333 	mutex_exit(&chmp->chm_lock_sizes);
334 
335 	KASSERT(cheb->used_size <= chmp->chm_ebh->eb_size);
336 	//dbg(" A: free_size: %d\n", cheb->free_size);
337 
338 	KASSERT(cheb->used_size + cheb->free_size + cheb->dirty_size + cheb->unchecked_size + cheb->wasted_size == chmp->chm_ebh->eb_size);
339 
340 
341 //	fd = pvc->scan_dirents;
342 	/*dbg("START\n");
343 	  while (fd) {
344 	  dbg("dirent dump:\n");
345 	  dbg(" ->vno:     %d\n", fd->vno);
346 	  dbg(" ->version: %ld\n", fd->version);
347 	  dbg(" ->nhash:   0x%x\n", fd->nhash);
348 	  dbg(" ->nsize:   %d\n", fd->nsize);
349 	  dbg(" ->name:    %s\n", fd->name);
350 	  dbg(" ->type:    %d\n", fd->type);
351 	  fd = fd->next;
352 	  }
353 	  dbg("END\n");*/
354 }
355 /**
356  * chfs_scan_check_dirent_node - check vnode crc and add to vnode cache
357  * @chmp: CHFS main descriptor structure
358  * @cheb: eraseblock informations
359  * @buf: directory entry to check
360  * @ofs: offset in eraseblock where dirent starts
361  */
362 int
363 chfs_scan_check_dirent_node(struct chfs_mount *chmp,
364     struct chfs_eraseblock *cheb, void *buf, off_t ofs)
365 {
366 	int err, namelen;
367 	uint32_t crc;
368 	struct chfs_dirent *fd;
369 	struct chfs_vnode_cache *vc;
370 	struct chfs_flash_dirent_node *dirent = buf;
371 
372 	//struct chfs_node_ref *tmp;
373 
374 	crc = crc32(0, (uint8_t *)dirent, sizeof(*dirent) - 4);
375 	if (crc != le32toh(dirent->node_crc)) {
376 		err = chfs_update_eb_dirty(chmp, cheb, le32toh(dirent->length));
377 		if (err)
378 			return err;
379 		return CHFS_NODE_BADCRC;
380 	}
381 	namelen = dirent->nsize;
382 
383 	fd = chfs_alloc_dirent(namelen + 1);
384 	if (!fd)
385 		return ENOMEM;
386 
387 	fd->nref = chfs_alloc_node_ref(cheb);
388 	if (!fd->nref)
389 		return ENOMEM;
390 
391 	KASSERT(fd->nref->nref_lnr == cheb->lnr);
392 
393 	memcpy(&fd->name, dirent->name, namelen);
394 	fd->nsize = namelen;
395 	fd->name[namelen] = 0;
396 	crc = crc32(0, fd->name, dirent->nsize);
397 	if (crc != le32toh(dirent->name_crc)) {
398 		chfs_err("Directory entry's name has bad crc: read: 0x%x, "
399 		    "calculated: 0x%x\n", le32toh(dirent->name_crc), crc);
400 		chfs_free_dirent(fd);
401 		err = chfs_update_eb_dirty(chmp, cheb, le32toh(dirent->length));
402 		if (err)
403 			return err;
404 		return CHFS_NODE_BADNAMECRC;
405 	}
406 
407 	/* Check vnode_cache of parent node */
408 	mutex_enter(&chmp->chm_lock_vnocache);
409 	vc = chfs_scan_make_vnode_cache(chmp, le64toh(dirent->pvno));
410 	mutex_exit(&chmp->chm_lock_vnocache);
411 	if (!vc) {
412 		chfs_free_dirent(fd);
413 		return ENOMEM;
414 	}
415 
416 	fd->nref->nref_offset = ofs;
417 
418 	dbg("add dirent to #%llu\n", (unsigned long long)vc->vno);
419 	chfs_add_node_to_list(chmp, vc, fd->nref, &vc->dirents);
420 	/*tmp = vc->dirents;
421 	  dbg("START|vno: %d dirents dump\n", vc->vno);
422 	  while (tmp) {
423 	  dbg(" ->nref->nref_lnr:    %d\n", tmp->lnr);
424 	  dbg(" ->nref->nref_offset: %d\n", tmp->offset);
425 	  tmp = tmp->next;
426 	  }
427 	  dbg("  END|vno: %d dirents dump\n", vc->vno);*/
428 
429 //	fd->next = NULL;
430 	fd->vno = le64toh(dirent->vno);
431 	fd->version = le64toh(dirent->version);
432 	fd->nhash = hash32_buf(fd->name, namelen, HASH32_BUF_INIT);
433 	fd->type = dirent->dtype;
434 
435 	/*dbg("dirent dump:\n");
436 	  dbg(" ->vno:     %d\n", fd->vno);
437 	  dbg(" ->version: %ld\n", fd->version);
438 	  dbg(" ->nhash:   0x%x\n", fd->nhash);
439 	  dbg(" ->nsize:   %d\n", fd->nsize);
440 	  dbg(" ->name:    %s\n", fd->name);
441 	  dbg(" ->type:    %d\n", fd->type);*/
442 
443 	chfs_add_fd_to_list(chmp, fd, vc);
444 
445 	/*struct chfs_node_ref *tmp;
446 	  tmp = vc->dirents;
447 	  dbg("START|vno: %d dirents dump\n", vc->vno);
448 	  while (tmp) {
449 	  dbg(" ->nref->nref_lnr:    %d\n", tmp->lnr);
450 	  dbg(" ->nref->nref_offset: %d\n", tmp->offset);
451 	  tmp = tmp->next;
452 	  }
453 	  dbg("  END|vno: %d dirents dump\n", vc->vno);*/
454 
455 	/*dbg("dirent dump:\n");
456 	  dbg(" ->magic:    0x%x\n", le16toh(dirent->magic));
457 	  dbg(" ->type:     %d\n", le16toh(dirent->type));
458 	  dbg(" ->length:   %d\n", le32toh(dirent->length));
459 	  dbg(" ->hdr_crc:  0x%x\n", le32toh(dirent->hdr_crc));
460 	  dbg(" ->vno:      %d\n", le64toh(dirent->vno));
461 	  dbg(" ->pvno:     %d\n", le64toh(dirent->pvno));
462 	  dbg(" ->version:  %ld\n", le64toh(dirent->version));
463 	  dbg(" ->mctime:   %d\n", le32toh(dirent->mctime));
464 	  dbg(" ->nsize:    %d\n", dirent->nsize);
465 	  dbg(" ->dtype:    %d\n", dirent->dtype);
466 	  dbg(" ->name_crc: 0x%x\n", le32toh(dirent->name_crc));
467 	  dbg(" ->node_crc: 0x%x\n", le32toh(dirent->node_crc));
468 	  dbg(" ->name:     %s\n", dirent->name);*/
469 
470 	return CHFS_NODE_OK;
471 }
472 
473 /**
474  * chfs_scan_check_data_node - check vnode crc and add to vnode cache
475  * @chmp: CHFS main descriptor structure
476  * @cheb: eraseblock informations
477  * @buf: data node to check
478  * @ofs: offset in eraseblock where data node starts
479  */
480 int
481 chfs_scan_check_data_node(struct chfs_mount *chmp,
482     struct chfs_eraseblock *cheb, void *buf, off_t ofs)
483 {
484 	KASSERT(mutex_owned(&chmp->chm_lock_mountfields));
485 	int err;
486 	uint32_t crc, vno;
487 	struct chfs_node_ref *nref;
488 	struct chfs_vnode_cache *vc;
489 	struct chfs_flash_data_node *dnode = buf;
490 
491 	crc = crc32(0, (uint8_t *)dnode, sizeof(struct chfs_flash_data_node) - 4);
492 	if (crc != le32toh(dnode->node_crc)) {
493 		err = chfs_update_eb_dirty(chmp, cheb, le32toh(dnode->length));
494 		if (err)
495 			return err;
496 		return CHFS_NODE_BADCRC;
497 	}
498 	/**
499 	 * Don't check data nodes crc and version here, it will be done in
500 	 * the background GC thread.
501 	 */
502 	nref = chfs_alloc_node_ref(cheb);
503 	if (!nref)
504 		return ENOMEM;
505 
506 	nref->nref_offset = ofs | CHFS_UNCHECKED_NODE_MASK;
507 
508 	KASSERT(nref->nref_lnr == cheb->lnr);
509 
510 	vno = le64toh(dnode->vno);
511 	mutex_enter(&chmp->chm_lock_vnocache);
512 	vc = chfs_vnode_cache_get(chmp, vno);
513 	if (!vc) {
514 		vc = chfs_scan_make_vnode_cache(chmp, vno);
515 		if (!vc)
516 			return ENOMEM;
517 	}
518 	mutex_exit(&chmp->chm_lock_vnocache);
519 	chfs_add_node_to_list(chmp, vc, nref, &vc->dnode);
520 
521 	dbg("chmpfree: %u, chebfree: %u, dnode: %u\n", chmp->chm_free_size, cheb->free_size, dnode->length);
522 
523 	mutex_enter(&chmp->chm_lock_sizes);
524 	chfs_change_size_free(chmp, cheb, -dnode->length);
525 	chfs_change_size_unchecked(chmp, cheb, dnode->length);
526 	mutex_exit(&chmp->chm_lock_sizes);
527 	return CHFS_NODE_OK;
528 }
529 
530 /**
531  * chfs_scan_classify_cheb - determine eraseblock's state
532  * @chmp: CHFS main descriptor structure
533  * @cheb: eraseblock to classify
534  */
535 int
536 chfs_scan_classify_cheb(struct chfs_mount *chmp,
537     struct chfs_eraseblock *cheb)
538 {
539 	if (cheb->free_size == chmp->chm_ebh->eb_size)
540 		return CHFS_BLK_STATE_FREE;
541 	else if (cheb->dirty_size < MAX_DIRTY_TO_CLEAN)
542 		return CHFS_BLK_STATE_CLEAN;
543 	else if (cheb->used_size || cheb->unchecked_size)
544 		return CHFS_BLK_STATE_PARTDIRTY;
545 	else
546 		return CHFS_BLK_STATE_ALLDIRTY;
547 }
548 
549 
550 /**
551  * chfs_scan_eraseblock - scans an eraseblock and looking for nodes
552  * @chmp: CHFS main descriptor structure
553  * @cheb: eraseblock to scan
554  *
555  * This function scans a whole eraseblock, checks the nodes on it and add them
556  * to the vnode cache.
557  * Returns eraseblock state on success, error code if fails.
558  */
559 int
560 chfs_scan_eraseblock(struct chfs_mount *chmp,
561     struct chfs_eraseblock *cheb) {
562 
563 	int err;
564 	size_t len, retlen;
565 	off_t ofs = 0;
566 	int lnr = cheb->lnr;
567 	u_char *buf;
568 	struct chfs_flash_node_hdr *nhdr;
569 	int read_free = 0;
570 	struct chfs_node_ref *nref;
571 
572 
573 	dbg("scanning eraseblock content: %d free_size: %d\n", cheb->lnr, cheb->free_size);
574 	dbg("scanned physical block: %d\n", chmp->chm_ebh->lmap[lnr]);
575 	buf = kmem_alloc(CHFS_MAX_NODE_SIZE, KM_SLEEP);
576 
577 	while((ofs + CHFS_NODE_HDR_SIZE) < chmp->chm_ebh->eb_size) {
578 		memset(buf, 0 , CHFS_MAX_NODE_SIZE);
579 		err = chfs_read_leb(chmp,
580 		    lnr, buf, ofs, CHFS_NODE_HDR_SIZE, &retlen);
581 		if (err) {
582 			return err;
583 		}
584 
585 		if (retlen != CHFS_NODE_HDR_SIZE) {
586 			chfs_err("Error reading node header: "
587 			    "read: %zu instead of: %zu\n",
588 			    CHFS_NODE_HDR_SIZE, retlen);
589 			return EIO;
590 		}
591 
592 		/* first we check if the buffer we read is full with 0xff, if yes maybe
593 		 * the blocks remaining area is free. We increase read_free and if it
594 		 * reaches MAX_READ_FREE we stop reading the block*/
595 		if (check_pattern(buf, 0xff, 0, CHFS_NODE_HDR_SIZE)) {
596 			read_free += CHFS_NODE_HDR_SIZE;
597 			if (read_free >= MAX_READ_FREE(chmp)) {
598 				dbg("rest of the block is free. Size: %d\n", cheb->free_size);
599 				return chfs_scan_classify_cheb(chmp, cheb);
600 			}
601 			ofs += CHFS_NODE_HDR_SIZE;
602 			continue;
603 		} else {
604 			chfs_update_eb_dirty(chmp, cheb, read_free);
605 			read_free = 0;
606 		}
607 
608 		nhdr = (struct chfs_flash_node_hdr *)buf;
609 
610 		err = chfs_scan_check_node_hdr(nhdr);
611 		if (err) {
612 			dbg("node hdr error\n");
613 			err = chfs_update_eb_dirty(chmp, cheb, 4);
614 			if (err) {
615 				return err;
616 			}
617 
618 			ofs += 4;
619 			continue;
620 		}
621 		ofs += CHFS_NODE_HDR_SIZE;
622 		if (ofs > chmp->chm_ebh->eb_size) {
623 			chfs_err("Second part of node is on the next eraseblock.\n");
624 			return EIO;
625 		}
626 		switch (le16toh(nhdr->type)) {
627 		case CHFS_NODETYPE_VNODE:
628 			/* Read up the node */
629 			//dbg("nodetype vnode\n");
630 			len = le32toh(nhdr->length) - CHFS_NODE_HDR_SIZE;
631 			err = chfs_read_leb(chmp,
632 			    lnr, buf + CHFS_NODE_HDR_SIZE,
633 			    ofs, len,  &retlen);
634 			if (err) {
635 				return err;
636 			}
637 
638 			if (retlen != len) {
639 				chfs_err("Error reading vnode: read: %zu instead of: %zu\n",
640 				    len, retlen);
641 				return EIO;
642 			}
643 			KASSERT(lnr == cheb->lnr);
644 			err = chfs_scan_check_vnode(chmp,
645 			    cheb, buf, ofs - CHFS_NODE_HDR_SIZE);
646 			if (err) {
647 				return err;
648 			}
649 
650 			//dbg("XXX5end\n");
651 			break;
652 		case CHFS_NODETYPE_DIRENT:
653 			/* Read up the node */
654 			//dbg("nodetype dirent\n");
655 			len = le32toh(nhdr->length) - CHFS_NODE_HDR_SIZE;
656 
657 			err = chfs_read_leb(chmp,
658 			    lnr, buf + CHFS_NODE_HDR_SIZE,
659 			    ofs, len, &retlen);
660 			if (err) {
661 				return err;
662 			}
663 
664 			if (retlen != len) {
665 				chfs_err("Error reading dirent node: read: %zu "
666 				    "instead of: %zu\n", len, retlen);
667 				return EIO;
668 			}
669 
670 			KASSERT(lnr == cheb->lnr);
671 
672 			err = chfs_scan_check_dirent_node(chmp,
673 			    cheb, buf, ofs - CHFS_NODE_HDR_SIZE);
674 			if (err) {
675 				return err;
676 			}
677 
678 			//dbg("XXX6end\n");
679 			break;
680 		case CHFS_NODETYPE_DATA:
681 			//dbg("nodetype data\n");
682 			len = sizeof(struct chfs_flash_data_node) -
683 			    CHFS_NODE_HDR_SIZE;
684 			err = chfs_read_leb(chmp,
685 			    lnr, buf + CHFS_NODE_HDR_SIZE,
686 			    ofs, len, &retlen);
687 			if (err) {
688 				return err;
689 			}
690 
691 			if (retlen != len) {
692 				chfs_err("Error reading data node: read: %zu "
693 				    "instead of: %zu\n", len, retlen);
694 				return EIO;
695 			}
696 			KASSERT(lnr == cheb->lnr);
697 			err = chfs_scan_check_data_node(chmp,
698 			    cheb, buf, ofs - CHFS_NODE_HDR_SIZE);
699 			if (err)
700 				return err;
701 
702 			//dbg("XXX7end\n");
703 			break;
704 		case CHFS_NODETYPE_PADDING:
705 			//dbg("nodetype padding\n");
706 			//dbg("padding len: %d\n", le32toh(nhdr->length));
707 			//dbg("BEF: cheb->free_size: %d\n", cheb->free_size);
708 			nref = chfs_alloc_node_ref(cheb);
709 			nref->nref_offset = ofs - CHFS_NODE_HDR_SIZE;
710 			nref->nref_offset = CHFS_GET_OFS(nref->nref_offset) |
711 			    CHFS_OBSOLETE_NODE_MASK;
712 
713 			err = chfs_update_eb_dirty(chmp, cheb,
714 			    le32toh(nhdr->length));
715 			//dbg("AFT: cheb->free_size: %d\n", cheb->free_size);
716 			if (err)
717 				return err;
718 
719 			//dbg("XXX8end\n");
720 			break;
721 		default:
722 			//dbg("nodetype ? (default)\n");
723 			/* Unknown node type, update dirty and skip */
724 			err = chfs_update_eb_dirty(chmp, cheb,
725 			    le32toh(nhdr->length));
726 			if (err)
727 				return err;
728 
729 			//dbg("XXX9end\n");
730 			break;
731 		}
732 		ofs += le32toh(nhdr->length) - CHFS_NODE_HDR_SIZE;
733 	}
734 
735 	KASSERT(cheb->used_size + cheb->free_size + cheb->dirty_size +
736 	    cheb->unchecked_size + cheb->wasted_size == chmp->chm_ebh->eb_size);
737 
738 	//dbg("XXX10\n");
739 	return chfs_scan_classify_cheb(chmp, cheb);
740 }
741