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1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/fs.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/rbtree.h>
19 #include <linux/crc32.h>
20 #include <linux/pagemap.h>
21 #include "nodelist.h"
22 
23 static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
24 				     struct jffs2_node_frag *this);
25 
jffs2_add_fd_to_list(struct jffs2_sb_info * c,struct jffs2_full_dirent * new,struct jffs2_full_dirent ** list)26 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
27 {
28 	struct jffs2_full_dirent **prev = list;
29 
30 	dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);
31 
32 	while ((*prev) && (*prev)->nhash <= new->nhash) {
33 		if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
34 			/* Duplicate. Free one */
35 			if (new->version < (*prev)->version) {
36 				dbg_dentlist("Eep! Marking new dirent node obsolete, old is \"%s\", ino #%u\n",
37 					(*prev)->name, (*prev)->ino);
38 				jffs2_mark_node_obsolete(c, new->raw);
39 				jffs2_free_full_dirent(new);
40 			} else {
41 				dbg_dentlist("marking old dirent \"%s\", ino #%u obsolete\n",
42 					(*prev)->name, (*prev)->ino);
43 				new->next = (*prev)->next;
44 				/* It may have been a 'placeholder' deletion dirent,
45 				   if jffs2_can_mark_obsolete() (see jffs2_do_unlink()) */
46 				if ((*prev)->raw)
47 					jffs2_mark_node_obsolete(c, ((*prev)->raw));
48 				jffs2_free_full_dirent(*prev);
49 				*prev = new;
50 			}
51 			return;
52 		}
53 		prev = &((*prev)->next);
54 	}
55 	new->next = *prev;
56 	*prev = new;
57 }
58 
jffs2_truncate_fragtree(struct jffs2_sb_info * c,struct rb_root * list,uint32_t size)59 uint32_t jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
60 {
61 	struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
62 
63 	dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);
64 
65 	/* We know frag->ofs <= size. That's what lookup does for us */
66 	if (frag && frag->ofs != size) {
67 		if (frag->ofs+frag->size > size) {
68 			frag->size = size - frag->ofs;
69 		}
70 		frag = frag_next(frag);
71 	}
72 	while (frag && frag->ofs >= size) {
73 		struct jffs2_node_frag *next = frag_next(frag);
74 
75 		frag_erase(frag, list);
76 		jffs2_obsolete_node_frag(c, frag);
77 		frag = next;
78 	}
79 
80 	if (size == 0)
81 		return 0;
82 
83 	frag = frag_last(list);
84 
85 	/* Sanity check for truncation to longer than we started with... */
86 	if (!frag)
87 		return 0;
88 	if (frag->ofs + frag->size < size)
89 		return frag->ofs + frag->size;
90 
91 	/* If the last fragment starts at the RAM page boundary, it is
92 	 * REF_PRISTINE irrespective of its size. */
93 	if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
94 		dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
95 			frag->ofs, frag->ofs + frag->size);
96 		frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
97 	}
98 	return size;
99 }
100 
jffs2_obsolete_node_frag(struct jffs2_sb_info * c,struct jffs2_node_frag * this)101 static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
102 				     struct jffs2_node_frag *this)
103 {
104 	if (this->node) {
105 		this->node->frags--;
106 		if (!this->node->frags) {
107 			/* The node has no valid frags left. It's totally obsoleted */
108 			dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
109 				ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
110 			jffs2_mark_node_obsolete(c, this->node->raw);
111 			jffs2_free_full_dnode(this->node);
112 		} else {
113 			dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
114 				ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
115 			mark_ref_normal(this->node->raw);
116 		}
117 
118 	}
119 	jffs2_free_node_frag(this);
120 }
121 
jffs2_fragtree_insert(struct jffs2_node_frag * newfrag,struct jffs2_node_frag * base)122 static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
123 {
124 	struct rb_node *parent = &base->rb;
125 	struct rb_node **link = &parent;
126 
127 	dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
128 
129 	while (*link) {
130 		parent = *link;
131 		base = rb_entry(parent, struct jffs2_node_frag, rb);
132 
133 		if (newfrag->ofs > base->ofs)
134 			link = &base->rb.rb_right;
135 		else if (newfrag->ofs < base->ofs)
136 			link = &base->rb.rb_left;
137 		else {
138 			JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
139 			BUG();
140 		}
141 	}
142 
143 	rb_link_node(&newfrag->rb, &base->rb, link);
144 }
145 
146 /*
147  * Allocate and initializes a new fragment.
148  */
new_fragment(struct jffs2_full_dnode * fn,uint32_t ofs,uint32_t size)149 static struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
150 {
151 	struct jffs2_node_frag *newfrag;
152 
153 	newfrag = jffs2_alloc_node_frag();
154 	if (likely(newfrag)) {
155 		newfrag->ofs = ofs;
156 		newfrag->size = size;
157 		newfrag->node = fn;
158 	} else {
159 		JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
160 	}
161 
162 	return newfrag;
163 }
164 
165 /*
166  * Called when there is no overlapping fragment exist. Inserts a hole before the new
167  * fragment and inserts the new fragment to the fragtree.
168  */
no_overlapping_node(struct jffs2_sb_info * c,struct rb_root * root,struct jffs2_node_frag * newfrag,struct jffs2_node_frag * this,uint32_t lastend)169 static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
170 		 	       struct jffs2_node_frag *newfrag,
171 			       struct jffs2_node_frag *this, uint32_t lastend)
172 {
173 	if (lastend < newfrag->node->ofs) {
174 		/* put a hole in before the new fragment */
175 		struct jffs2_node_frag *holefrag;
176 
177 		holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
178 		if (unlikely(!holefrag)) {
179 			jffs2_free_node_frag(newfrag);
180 			return -ENOMEM;
181 		}
182 
183 		if (this) {
184 			/* By definition, the 'this' node has no right-hand child,
185 			   because there are no frags with offset greater than it.
186 			   So that's where we want to put the hole */
187 			dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
188 				holefrag->ofs, holefrag->ofs + holefrag->size);
189 			rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
190 		} else {
191 			dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
192 				holefrag->ofs, holefrag->ofs + holefrag->size);
193 			rb_link_node(&holefrag->rb, NULL, &root->rb_node);
194 		}
195 		rb_insert_color(&holefrag->rb, root);
196 		this = holefrag;
197 	}
198 
199 	if (this) {
200 		/* By definition, the 'this' node has no right-hand child,
201 		   because there are no frags with offset greater than it.
202 		   So that's where we want to put new fragment */
203 		dbg_fragtree2("add the new node at the right\n");
204 		rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
205 	} else {
206 		dbg_fragtree2("insert the new node at the root of the tree\n");
207 		rb_link_node(&newfrag->rb, NULL, &root->rb_node);
208 	}
209 	rb_insert_color(&newfrag->rb, root);
210 
211 	return 0;
212 }
213 
214 /* Doesn't set inode->i_size */
jffs2_add_frag_to_fragtree(struct jffs2_sb_info * c,struct rb_root * root,struct jffs2_node_frag * newfrag)215 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
216 {
217 	struct jffs2_node_frag *this;
218 	uint32_t lastend;
219 
220 	/* Skip all the nodes which are completed before this one starts */
221 	this = jffs2_lookup_node_frag(root, newfrag->node->ofs);
222 
223 	if (this) {
224 		dbg_fragtree2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
225 			  this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
226 		lastend = this->ofs + this->size;
227 	} else {
228 		dbg_fragtree2("lookup gave no frag\n");
229 		lastend = 0;
230 	}
231 
232 	/* See if we ran off the end of the fragtree */
233 	if (lastend <= newfrag->ofs) {
234 		/* We did */
235 
236 		/* Check if 'this' node was on the same page as the new node.
237 		   If so, both 'this' and the new node get marked REF_NORMAL so
238 		   the GC can take a look.
239 		*/
240 		if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
241 			if (this->node)
242 				mark_ref_normal(this->node->raw);
243 			mark_ref_normal(newfrag->node->raw);
244 		}
245 
246 		return no_overlapping_node(c, root, newfrag, this, lastend);
247 	}
248 
249 	if (this->node)
250 		dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
251 		this->ofs, this->ofs + this->size,
252 		ref_offset(this->node->raw), ref_flags(this->node->raw));
253 	else
254 		dbg_fragtree2("dealing with hole frag %u-%u.\n",
255 		this->ofs, this->ofs + this->size);
256 
257 	/* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
258 	 * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
259 	 */
260 	if (newfrag->ofs > this->ofs) {
261 		/* This node isn't completely obsoleted. The start of it remains valid */
262 
263 		/* Mark the new node and the partially covered node REF_NORMAL -- let
264 		   the GC take a look at them */
265 		mark_ref_normal(newfrag->node->raw);
266 		if (this->node)
267 			mark_ref_normal(this->node->raw);
268 
269 		if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
270 			/* The new node splits 'this' frag into two */
271 			struct jffs2_node_frag *newfrag2;
272 
273 			if (this->node)
274 				dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
275 					this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
276 			else
277 				dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
278 					this->ofs, this->ofs+this->size);
279 
280 			/* New second frag pointing to this's node */
281 			newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
282 						this->ofs + this->size - newfrag->ofs - newfrag->size);
283 			if (unlikely(!newfrag2))
284 				return -ENOMEM;
285 			if (this->node)
286 				this->node->frags++;
287 
288 			/* Adjust size of original 'this' */
289 			this->size = newfrag->ofs - this->ofs;
290 
291 			/* Now, we know there's no node with offset
292 			   greater than this->ofs but smaller than
293 			   newfrag2->ofs or newfrag->ofs, for obvious
294 			   reasons. So we can do a tree insert from
295 			   'this' to insert newfrag, and a tree insert
296 			   from newfrag to insert newfrag2. */
297 			jffs2_fragtree_insert(newfrag, this);
298 			rb_insert_color(&newfrag->rb, root);
299 
300 			jffs2_fragtree_insert(newfrag2, newfrag);
301 			rb_insert_color(&newfrag2->rb, root);
302 
303 			return 0;
304 		}
305 		/* New node just reduces 'this' frag in size, doesn't split it */
306 		this->size = newfrag->ofs - this->ofs;
307 
308 		/* Again, we know it lives down here in the tree */
309 		jffs2_fragtree_insert(newfrag, this);
310 		rb_insert_color(&newfrag->rb, root);
311 	} else {
312 		/* New frag starts at the same point as 'this' used to. Replace
313 		   it in the tree without doing a delete and insertion */
314 		dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
315 			  newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
316 
317 		rb_replace_node(&this->rb, &newfrag->rb, root);
318 
319 		if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
320 			dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
321 			jffs2_obsolete_node_frag(c, this);
322 		} else {
323 			this->ofs += newfrag->size;
324 			this->size -= newfrag->size;
325 
326 			jffs2_fragtree_insert(this, newfrag);
327 			rb_insert_color(&this->rb, root);
328 			return 0;
329 		}
330 	}
331 	/* OK, now we have newfrag added in the correct place in the tree, but
332 	   frag_next(newfrag) may be a fragment which is overlapped by it
333 	*/
334 	while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
335 		/* 'this' frag is obsoleted completely. */
336 		dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
337 			this, this->ofs, this->ofs+this->size);
338 		rb_erase(&this->rb, root);
339 		jffs2_obsolete_node_frag(c, this);
340 	}
341 	/* Now we're pointing at the first frag which isn't totally obsoleted by
342 	   the new frag */
343 
344 	if (!this || newfrag->ofs + newfrag->size == this->ofs)
345 		return 0;
346 
347 	/* Still some overlap but we don't need to move it in the tree */
348 	this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
349 	this->ofs = newfrag->ofs + newfrag->size;
350 
351 	/* And mark them REF_NORMAL so the GC takes a look at them */
352 	if (this->node)
353 		mark_ref_normal(this->node->raw);
354 	mark_ref_normal(newfrag->node->raw);
355 
356 	return 0;
357 }
358 
359 /*
360  * Given an inode, probably with existing tree of fragments, add the new node
361  * to the fragment tree.
362  */
jffs2_add_full_dnode_to_inode(struct jffs2_sb_info * c,struct jffs2_inode_info * f,struct jffs2_full_dnode * fn)363 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
364 {
365 	int ret;
366 	struct jffs2_node_frag *newfrag;
367 
368 	if (unlikely(!fn->size))
369 		return 0;
370 
371 	newfrag = new_fragment(fn, fn->ofs, fn->size);
372 	if (unlikely(!newfrag))
373 		return -ENOMEM;
374 	newfrag->node->frags = 1;
375 
376 	dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
377 		  fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
378 
379 	ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
380 	if (unlikely(ret))
381 		return ret;
382 
383 	/* If we now share a page with other nodes, mark either previous
384 	   or next node REF_NORMAL, as appropriate.  */
385 	if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
386 		struct jffs2_node_frag *prev = frag_prev(newfrag);
387 
388 		mark_ref_normal(fn->raw);
389 		/* If we don't start at zero there's _always_ a previous */
390 		if (prev->node)
391 			mark_ref_normal(prev->node->raw);
392 	}
393 
394 	if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
395 		struct jffs2_node_frag *next = frag_next(newfrag);
396 
397 		if (next) {
398 			mark_ref_normal(fn->raw);
399 			if (next->node)
400 				mark_ref_normal(next->node->raw);
401 		}
402 	}
403 	jffs2_dbg_fragtree_paranoia_check_nolock(f);
404 
405 	return 0;
406 }
407 
jffs2_set_inocache_state(struct jffs2_sb_info * c,struct jffs2_inode_cache * ic,int state)408 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
409 {
410 	spin_lock(&c->inocache_lock);
411 	ic->state = state;
412 	wake_up(&c->inocache_wq);
413 	spin_unlock(&c->inocache_lock);
414 }
415 
416 /* During mount, this needs no locking. During normal operation, its
417    callers want to do other stuff while still holding the inocache_lock.
418    Rather than introducing special case get_ino_cache functions or
419    callbacks, we just let the caller do the locking itself. */
420 
jffs2_get_ino_cache(struct jffs2_sb_info * c,uint32_t ino)421 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
422 {
423 	struct jffs2_inode_cache *ret;
424 
425 	ret = c->inocache_list[ino % c->inocache_hashsize];
426 	while (ret && ret->ino < ino) {
427 		ret = ret->next;
428 	}
429 
430 	if (ret && ret->ino != ino)
431 		ret = NULL;
432 
433 	return ret;
434 }
435 
jffs2_add_ino_cache(struct jffs2_sb_info * c,struct jffs2_inode_cache * new)436 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
437 {
438 	struct jffs2_inode_cache **prev;
439 
440 	spin_lock(&c->inocache_lock);
441 	if (!new->ino)
442 		new->ino = ++c->highest_ino;
443 
444 	dbg_inocache("add %p (ino #%u)\n", new, new->ino);
445 
446 	prev = &c->inocache_list[new->ino % c->inocache_hashsize];
447 
448 	while ((*prev) && (*prev)->ino < new->ino) {
449 		prev = &(*prev)->next;
450 	}
451 	new->next = *prev;
452 	*prev = new;
453 
454 	spin_unlock(&c->inocache_lock);
455 }
456 
jffs2_del_ino_cache(struct jffs2_sb_info * c,struct jffs2_inode_cache * old)457 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
458 {
459 	struct jffs2_inode_cache **prev;
460 
461 #ifdef CONFIG_JFFS2_FS_XATTR
462 	BUG_ON(old->xref);
463 #endif
464 	dbg_inocache("del %p (ino #%u)\n", old, old->ino);
465 	spin_lock(&c->inocache_lock);
466 
467 	prev = &c->inocache_list[old->ino % c->inocache_hashsize];
468 
469 	while ((*prev) && (*prev)->ino < old->ino) {
470 		prev = &(*prev)->next;
471 	}
472 	if ((*prev) == old) {
473 		*prev = old->next;
474 	}
475 
476 	/* Free it now unless it's in READING or CLEARING state, which
477 	   are the transitions upon read_inode() and clear_inode(). The
478 	   rest of the time we know nobody else is looking at it, and
479 	   if it's held by read_inode() or clear_inode() they'll free it
480 	   for themselves. */
481 	if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
482 		jffs2_free_inode_cache(old);
483 
484 	spin_unlock(&c->inocache_lock);
485 }
486 
jffs2_free_ino_caches(struct jffs2_sb_info * c)487 void jffs2_free_ino_caches(struct jffs2_sb_info *c)
488 {
489 	int i;
490 	struct jffs2_inode_cache *this, *next;
491 
492 	for (i=0; i < c->inocache_hashsize; i++) {
493 		this = c->inocache_list[i];
494 		while (this) {
495 			next = this->next;
496 			jffs2_xattr_free_inode(c, this);
497 			jffs2_free_inode_cache(this);
498 			this = next;
499 		}
500 		c->inocache_list[i] = NULL;
501 	}
502 }
503 
jffs2_free_raw_node_refs(struct jffs2_sb_info * c)504 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
505 {
506 	int i;
507 	struct jffs2_raw_node_ref *this, *next;
508 
509 	for (i=0; i<c->nr_blocks; i++) {
510 		this = c->blocks[i].first_node;
511 		while (this) {
512 			if (this[REFS_PER_BLOCK].flash_offset == REF_LINK_NODE)
513 				next = this[REFS_PER_BLOCK].next_in_ino;
514 			else
515 				next = NULL;
516 
517 			jffs2_free_refblock(this);
518 			this = next;
519 		}
520 		c->blocks[i].first_node = c->blocks[i].last_node = NULL;
521 	}
522 }
523 
jffs2_lookup_node_frag(struct rb_root * fragtree,uint32_t offset)524 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
525 {
526 	/* The common case in lookup is that there will be a node
527 	   which precisely matches. So we go looking for that first */
528 	struct rb_node *next;
529 	struct jffs2_node_frag *prev = NULL;
530 	struct jffs2_node_frag *frag = NULL;
531 
532 	dbg_fragtree2("root %p, offset %d\n", fragtree, offset);
533 
534 	next = fragtree->rb_node;
535 
536 	while(next) {
537 		frag = rb_entry(next, struct jffs2_node_frag, rb);
538 
539 		if (frag->ofs + frag->size <= offset) {
540 			/* Remember the closest smaller match on the way down */
541 			if (!prev || frag->ofs > prev->ofs)
542 				prev = frag;
543 			next = frag->rb.rb_right;
544 		} else if (frag->ofs > offset) {
545 			next = frag->rb.rb_left;
546 		} else {
547 			return frag;
548 		}
549 	}
550 
551 	/* Exact match not found. Go back up looking at each parent,
552 	   and return the closest smaller one */
553 
554 	if (prev)
555 		dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
556 			  prev->ofs, prev->ofs+prev->size);
557 	else
558 		dbg_fragtree2("returning NULL, empty fragtree\n");
559 
560 	return prev;
561 }
562 
563 /* Pass 'c' argument to indicate that nodes should be marked obsolete as
564    they're killed. */
jffs2_kill_fragtree(struct rb_root * root,struct jffs2_sb_info * c)565 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
566 {
567 	struct jffs2_node_frag *frag;
568 	struct jffs2_node_frag *parent;
569 
570 	if (!root->rb_node)
571 		return;
572 
573 	dbg_fragtree("killing\n");
574 
575 	frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
576 	while(frag) {
577 		if (frag->rb.rb_left) {
578 			frag = frag_left(frag);
579 			continue;
580 		}
581 		if (frag->rb.rb_right) {
582 			frag = frag_right(frag);
583 			continue;
584 		}
585 
586 		if (frag->node && !(--frag->node->frags)) {
587 			/* Not a hole, and it's the final remaining frag
588 			   of this node. Free the node */
589 			if (c)
590 				jffs2_mark_node_obsolete(c, frag->node->raw);
591 
592 			jffs2_free_full_dnode(frag->node);
593 		}
594 		parent = frag_parent(frag);
595 		if (parent) {
596 			if (frag_left(parent) == frag)
597 				parent->rb.rb_left = NULL;
598 			else
599 				parent->rb.rb_right = NULL;
600 		}
601 
602 		jffs2_free_node_frag(frag);
603 		frag = parent;
604 
605 		cond_resched();
606 	}
607 }
608 
jffs2_link_node_ref(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb,uint32_t ofs,uint32_t len,struct jffs2_inode_cache * ic)609 struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
610 					       struct jffs2_eraseblock *jeb,
611 					       uint32_t ofs, uint32_t len,
612 					       struct jffs2_inode_cache *ic)
613 {
614 	struct jffs2_raw_node_ref *ref;
615 
616 	BUG_ON(!jeb->allocated_refs);
617 	jeb->allocated_refs--;
618 
619 	ref = jeb->last_node;
620 
621 	dbg_noderef("Last node at %p is (%08x,%p)\n", ref, ref->flash_offset,
622 		    ref->next_in_ino);
623 
624 	while (ref->flash_offset != REF_EMPTY_NODE) {
625 		if (ref->flash_offset == REF_LINK_NODE)
626 			ref = ref->next_in_ino;
627 		else
628 			ref++;
629 	}
630 
631 	dbg_noderef("New ref is %p (%08x becomes %08x,%p) len 0x%x\n", ref,
632 		    ref->flash_offset, ofs, ref->next_in_ino, len);
633 
634 	ref->flash_offset = ofs;
635 
636 	if (!jeb->first_node) {
637 		jeb->first_node = ref;
638 		BUG_ON(ref_offset(ref) != jeb->offset);
639 	} else if (unlikely(ref_offset(ref) != jeb->offset + c->sector_size - jeb->free_size)) {
640 		uint32_t last_len = ref_totlen(c, jeb, jeb->last_node);
641 
642 		JFFS2_ERROR("Adding new ref %p at (0x%08x-0x%08x) not immediately after previous (0x%08x-0x%08x)\n",
643 			    ref, ref_offset(ref), ref_offset(ref)+len,
644 			    ref_offset(jeb->last_node),
645 			    ref_offset(jeb->last_node)+last_len);
646 		BUG();
647 	}
648 	jeb->last_node = ref;
649 
650 	if (ic) {
651 		ref->next_in_ino = ic->nodes;
652 		ic->nodes = ref;
653 	} else {
654 		ref->next_in_ino = NULL;
655 	}
656 
657 	switch(ref_flags(ref)) {
658 	case REF_UNCHECKED:
659 		c->unchecked_size += len;
660 		jeb->unchecked_size += len;
661 		break;
662 
663 	case REF_NORMAL:
664 	case REF_PRISTINE:
665 		c->used_size += len;
666 		jeb->used_size += len;
667 		break;
668 
669 	case REF_OBSOLETE:
670 		c->dirty_size += len;
671 		jeb->dirty_size += len;
672 		break;
673 	}
674 	c->free_size -= len;
675 	jeb->free_size -= len;
676 
677 #ifdef TEST_TOTLEN
678 	/* Set (and test) __totlen field... for now */
679 	ref->__totlen = len;
680 	ref_totlen(c, jeb, ref);
681 #endif
682 	return ref;
683 }
684 
685 /* No locking, no reservation of 'ref'. Do not use on a live file system */
jffs2_scan_dirty_space(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb,uint32_t size)686 int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
687 			   uint32_t size)
688 {
689 	if (!size)
690 		return 0;
691 	if (unlikely(size > jeb->free_size)) {
692 		pr_crit("Dirty space 0x%x larger then free_size 0x%x (wasted 0x%x)\n",
693 			size, jeb->free_size, jeb->wasted_size);
694 		BUG();
695 	}
696 	/* REF_EMPTY_NODE is !obsolete, so that works OK */
697 	if (jeb->last_node && ref_obsolete(jeb->last_node)) {
698 #ifdef TEST_TOTLEN
699 		jeb->last_node->__totlen += size;
700 #endif
701 		c->dirty_size += size;
702 		c->free_size -= size;
703 		jeb->dirty_size += size;
704 		jeb->free_size -= size;
705 	} else {
706 		uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
707 		ofs |= REF_OBSOLETE;
708 
709 		jffs2_link_node_ref(c, jeb, ofs, size, NULL);
710 	}
711 
712 	return 0;
713 }
714 
715 /* Calculate totlen from surrounding nodes or eraseblock */
__ref_totlen(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb,struct jffs2_raw_node_ref * ref)716 static inline uint32_t __ref_totlen(struct jffs2_sb_info *c,
717 				    struct jffs2_eraseblock *jeb,
718 				    struct jffs2_raw_node_ref *ref)
719 {
720 	uint32_t ref_end;
721 	struct jffs2_raw_node_ref *next_ref = ref_next(ref);
722 
723 	if (next_ref)
724 		ref_end = ref_offset(next_ref);
725 	else {
726 		if (!jeb)
727 			jeb = &c->blocks[ref->flash_offset / c->sector_size];
728 
729 		/* Last node in block. Use free_space */
730 		if (unlikely(ref != jeb->last_node)) {
731 			pr_crit("ref %p @0x%08x is not jeb->last_node (%p @0x%08x)\n",
732 				ref, ref_offset(ref), jeb->last_node,
733 				jeb->last_node ?
734 				ref_offset(jeb->last_node) : 0);
735 			BUG();
736 		}
737 		ref_end = jeb->offset + c->sector_size - jeb->free_size;
738 	}
739 	return ref_end - ref_offset(ref);
740 }
741 
__jffs2_ref_totlen(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb,struct jffs2_raw_node_ref * ref)742 uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
743 			    struct jffs2_raw_node_ref *ref)
744 {
745 	uint32_t ret;
746 
747 	ret = __ref_totlen(c, jeb, ref);
748 
749 #ifdef TEST_TOTLEN
750 	if (unlikely(ret != ref->__totlen)) {
751 		if (!jeb)
752 			jeb = &c->blocks[ref->flash_offset / c->sector_size];
753 
754 		pr_crit("Totlen for ref at %p (0x%08x-0x%08x) miscalculated as 0x%x instead of %x\n",
755 			ref, ref_offset(ref), ref_offset(ref) + ref->__totlen,
756 			ret, ref->__totlen);
757 		if (ref_next(ref)) {
758 			pr_crit("next %p (0x%08x-0x%08x)\n",
759 				ref_next(ref), ref_offset(ref_next(ref)),
760 				ref_offset(ref_next(ref)) + ref->__totlen);
761 		} else
762 			pr_crit("No next ref. jeb->last_node is %p\n",
763 				jeb->last_node);
764 
765 		pr_crit("jeb->wasted_size %x, dirty_size %x, used_size %x, free_size %x\n",
766 			jeb->wasted_size, jeb->dirty_size, jeb->used_size,
767 			jeb->free_size);
768 
769 #if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
770 		__jffs2_dbg_dump_node_refs_nolock(c, jeb);
771 #endif
772 
773 		WARN_ON(1);
774 
775 		ret = ref->__totlen;
776 	}
777 #endif /* TEST_TOTLEN */
778 	return ret;
779 }
780