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#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/mtd/mtd.h>
15#include <linux/compiler.h>
16#include <linux/sched.h> /* For cond_resched() */
17#include "nodelist.h"
18#include "debug.h"
19
20/**
21 *	jffs2_reserve_space - request physical space to write nodes to flash
22 *	@c: superblock info
23 *	@minsize: Minimum acceptable size of allocation
24 *	@len: Returned value of allocation length
25 *	@prio: Allocation type - ALLOC_{NORMAL,DELETION}
26 *
27 *	Requests a block of physical space on the flash. Returns zero for success
28 *	and puts 'len' into the appropriate place, or returns -ENOSPC or other
29 *	error if appropriate. Doesn't return len since that's
30 *
31 *	If it returns zero, jffs2_reserve_space() also downs the per-filesystem
32 *	allocation semaphore, to prevent more than one allocation from being
33 *	active at any time. The semaphore is later released by jffs2_commit_allocation()
34 *
35 *	jffs2_reserve_space() may trigger garbage collection in order to make room
36 *	for the requested allocation.
37 */
38
39static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
40				  uint32_t *len, uint32_t sumsize);
41
42int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
43			uint32_t *len, int prio, uint32_t sumsize)
44{
45	int ret = -EAGAIN;
46	int blocksneeded = c->resv_blocks_write;
47	/* align it */
48	minsize = PAD(minsize);
49
50	D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
51	down(&c->alloc_sem);
52
53	D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
54
55	spin_lock(&c->erase_completion_lock);
56
57	/* this needs a little more thought (true <tglx> :)) */
58	while(ret == -EAGAIN) {
59		while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
60			int ret;
61			uint32_t dirty, avail;
62
63			/* calculate real dirty size
64			 * dirty_size contains blocks on erase_pending_list
65			 * those blocks are counted in c->nr_erasing_blocks.
66			 * If one block is actually erased, it is not longer counted as dirty_space
67			 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
68			 * with c->nr_erasing_blocks * c->sector_size again.
69			 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
70			 * This helps us to force gc and pick eventually a clean block to spread the load.
71			 * We add unchecked_size here, as we hopefully will find some space to use.
72			 * This will affect the sum only once, as gc first finishes checking
73			 * of nodes.
74			 */
75			dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
76			if (dirty < c->nospc_dirty_size) {
77				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
78					D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
79					break;
80				}
81				D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
82					  dirty, c->unchecked_size, c->sector_size));
83
84				spin_unlock(&c->erase_completion_lock);
85				up(&c->alloc_sem);
86				return -ENOSPC;
87			}
88
89			/* Calc possibly available space. Possibly available means that we
90			 * don't know, if unchecked size contains obsoleted nodes, which could give us some
91			 * more usable space. This will affect the sum only once, as gc first finishes checking
92			 * of nodes.
93			 + Return -ENOSPC, if the maximum possibly available space is less or equal than
94			 * blocksneeded * sector_size.
95			 * This blocks endless gc looping on a filesystem, which is nearly full, even if
96			 * the check above passes.
97			 */
98			avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
99			if ( (avail / c->sector_size) <= blocksneeded) {
100				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
101					D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
102					break;
103				}
104
105				D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
106					  avail, blocksneeded * c->sector_size));
107				spin_unlock(&c->erase_completion_lock);
108				up(&c->alloc_sem);
109				return -ENOSPC;
110			}
111
112			up(&c->alloc_sem);
113
114			D1(printk(KERN_DEBUG "Triggering GC pass. nr_free_blocks %d, nr_erasing_blocks %d, free_size 0x%08x, dirty_size 0x%08x, wasted_size 0x%08x, used_size 0x%08x, erasing_size 0x%08x, bad_size 0x%08x (total 0x%08x of 0x%08x)\n",
115				  c->nr_free_blocks, c->nr_erasing_blocks, c->free_size, c->dirty_size, c->wasted_size, c->used_size, c->erasing_size, c->bad_size,
116				  c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
117			spin_unlock(&c->erase_completion_lock);
118
119			ret = jffs2_garbage_collect_pass(c);
120			if (ret)
121				return ret;
122
123			cond_resched();
124
125			if (signal_pending(current))
126				return -EINTR;
127
128			down(&c->alloc_sem);
129			spin_lock(&c->erase_completion_lock);
130		}
131
132		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
133		if (ret) {
134			D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
135		}
136	}
137	spin_unlock(&c->erase_completion_lock);
138	if (!ret)
139		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
140	if (ret)
141		up(&c->alloc_sem);
142	return ret;
143}
144
145int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
146			   uint32_t *len, uint32_t sumsize)
147{
148	int ret = -EAGAIN;
149	minsize = PAD(minsize);
150
151	D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
152
153	spin_lock(&c->erase_completion_lock);
154	while(ret == -EAGAIN) {
155		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
156		if (ret) {
157		        D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
158		}
159	}
160	spin_unlock(&c->erase_completion_lock);
161	if (!ret)
162		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
163
164	return ret;
165}
166
167
168/* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
169
170static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
171{
172
173	if (c->nextblock == NULL) {
174		D1(printk(KERN_DEBUG "jffs2_close_nextblock: Erase block at 0x%08x has already been placed in a list\n",
175		  jeb->offset));
176		return;
177	}
178	/* Check, if we have a dirty block now, or if it was dirty already */
179	if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
180		c->dirty_size += jeb->wasted_size;
181		c->wasted_size -= jeb->wasted_size;
182		jeb->dirty_size += jeb->wasted_size;
183		jeb->wasted_size = 0;
184		if (VERYDIRTY(c, jeb->dirty_size)) {
185			D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
186			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
187			list_add_tail(&jeb->list, &c->very_dirty_list);
188		} else {
189			D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
190			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
191			list_add_tail(&jeb->list, &c->dirty_list);
192		}
193	} else {
194		D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
195		  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
196		list_add_tail(&jeb->list, &c->clean_list);
197	}
198	c->nextblock = NULL;
199
200}
201
202/* Select a new jeb for nextblock */
203
204static int jffs2_find_nextblock(struct jffs2_sb_info *c)
205{
206	struct list_head *next;
207
208	/* Take the next block off the 'free' list */
209
210	if (list_empty(&c->free_list)) {
211
212		if (!c->nr_erasing_blocks &&
213			!list_empty(&c->erasable_list)) {
214			struct jffs2_eraseblock *ejeb;
215
216			ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
217			list_move_tail(&ejeb->list, &c->erase_pending_list);
218			c->nr_erasing_blocks++;
219			jffs2_erase_pending_trigger(c);
220			D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
221				  ejeb->offset));
222		}
223
224		if (!c->nr_erasing_blocks &&
225			!list_empty(&c->erasable_pending_wbuf_list)) {
226			D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
227			/* c->nextblock is NULL, no update to c->nextblock allowed */
228			spin_unlock(&c->erase_completion_lock);
229			jffs2_flush_wbuf_pad(c);
230			spin_lock(&c->erase_completion_lock);
231			/* Have another go. It'll be on the erasable_list now */
232			return -EAGAIN;
233		}
234
235		if (!c->nr_erasing_blocks) {
236			/* Ouch. We're in GC, or we wouldn't have got here.
237			   And there's no space left. At all. */
238			printk(KERN_CRIT "Argh. No free space left for GC. nr_erasing_blocks is %d. nr_free_blocks is %d. (erasableempty: %s, erasingempty: %s, erasependingempty: %s)\n",
239				   c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
240				   list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
241			return -ENOSPC;
242		}
243
244		spin_unlock(&c->erase_completion_lock);
245		/* Don't wait for it; just erase one right now */
246		jffs2_erase_pending_blocks(c, 1);
247		spin_lock(&c->erase_completion_lock);
248
249		/* An erase may have failed, decreasing the
250		   amount of free space available. So we must
251		   restart from the beginning */
252		return -EAGAIN;
253	}
254
255	next = c->free_list.next;
256	list_del(next);
257	c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
258	c->nr_free_blocks--;
259
260	jffs2_sum_reset_collected(c->summary); /* reset collected summary */
261
262	D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
263
264	return 0;
265}
266
267/* Called with alloc sem _and_ erase_completion_lock */
268static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
269				  uint32_t *len, uint32_t sumsize)
270{
271	struct jffs2_eraseblock *jeb = c->nextblock;
272	uint32_t reserved_size;				/* for summary information at the end of the jeb */
273	int ret;
274
275 restart:
276	reserved_size = 0;
277
278	if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
279							/* NOSUM_SIZE means not to generate summary */
280
281		if (jeb) {
282			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
283			dbg_summary("minsize=%d , jeb->free=%d ,"
284						"summary->size=%d , sumsize=%d\n",
285						minsize, jeb->free_size,
286						c->summary->sum_size, sumsize);
287		}
288
289		/* Is there enough space for writing out the current node, or we have to
290		   write out summary information now, close this jeb and select new nextblock? */
291		if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
292					JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
293
294			/* Has summary been disabled for this jeb? */
295			if (jffs2_sum_is_disabled(c->summary)) {
296				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
297				goto restart;
298			}
299
300			/* Writing out the collected summary information */
301			dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
302			ret = jffs2_sum_write_sumnode(c);
303
304			if (ret)
305				return ret;
306
307			if (jffs2_sum_is_disabled(c->summary)) {
308				/* jffs2_write_sumnode() couldn't write out the summary information
309				   diabling summary for this jeb and free the collected information
310				 */
311				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
312				goto restart;
313			}
314
315			jffs2_close_nextblock(c, jeb);
316			jeb = NULL;
317			/* keep always valid value in reserved_size */
318			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
319		}
320	} else {
321		if (jeb && minsize > jeb->free_size) {
322			uint32_t waste;
323
324			/* Skip the end of this block and file it as having some dirty space */
325			/* If there's a pending write to it, flush now */
326
327			if (jffs2_wbuf_dirty(c)) {
328				spin_unlock(&c->erase_completion_lock);
329				D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
330				jffs2_flush_wbuf_pad(c);
331				spin_lock(&c->erase_completion_lock);
332				jeb = c->nextblock;
333				goto restart;
334			}
335
336			spin_unlock(&c->erase_completion_lock);
337
338			ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
339			if (ret)
340				return ret;
341			/* Just lock it again and continue. Nothing much can change because
342			   we hold c->alloc_sem anyway. In fact, it's not entirely clear why
343			   we hold c->erase_completion_lock in the majority of this function...
344			   but that's a question for another (more caffeine-rich) day. */
345			spin_lock(&c->erase_completion_lock);
346
347			waste = jeb->free_size;
348			jffs2_link_node_ref(c, jeb,
349					    (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
350					    waste, NULL);
351			jeb->dirty_size -= waste;
352			c->dirty_size -= waste;
353			jeb->wasted_size += waste;
354			c->wasted_size += waste;
355
356			jffs2_close_nextblock(c, jeb);
357			jeb = NULL;
358		}
359	}
360
361	if (!jeb) {
362
363		ret = jffs2_find_nextblock(c);
364		if (ret)
365			return ret;
366
367		jeb = c->nextblock;
368
369		if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
370			printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
371			goto restart;
372		}
373	}
374	/* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
375	   enough space */
376	*len = jeb->free_size - reserved_size;
377
378	if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
379	    !jeb->first_node->next_in_ino) {
380		/* Only node in it beforehand was a CLEANMARKER node (we think).
381		   So mark it obsolete now that there's going to be another node
382		   in the block. This will reduce used_size to zero but We've
383		   already set c->nextblock so that jffs2_mark_node_obsolete()
384		   won't try to refile it to the dirty_list.
385		*/
386		spin_unlock(&c->erase_completion_lock);
387		jffs2_mark_node_obsolete(c, jeb->first_node);
388		spin_lock(&c->erase_completion_lock);
389	}
390
391	D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
392		  *len, jeb->offset + (c->sector_size - jeb->free_size)));
393	return 0;
394}
395
396/**
397 *	jffs2_add_physical_node_ref - add a physical node reference to the list
398 *	@c: superblock info
399 *	@new: new node reference to add
400 *	@len: length of this physical node
401 *
402 *	Should only be used to report nodes for which space has been allocated
403 *	by jffs2_reserve_space.
404 *
405 *	Must be called with the alloc_sem held.
406 */
407
408struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
409						       uint32_t ofs, uint32_t len,
410						       struct jffs2_inode_cache *ic)
411{
412	struct jffs2_eraseblock *jeb;
413	struct jffs2_raw_node_ref *new;
414
415	jeb = &c->blocks[ofs / c->sector_size];
416
417	D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
418		  ofs & ~3, ofs & 3, len));
419	/* Allow non-obsolete nodes only to be added at the end of c->nextblock,
420	   if c->nextblock is set. Note that wbuf.c will file obsolete nodes
421	   even after refiling c->nextblock */
422	if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
423	    && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
424		printk(KERN_WARNING "argh. node added in wrong place\n");
425		return ERR_PTR(-EINVAL);
426	}
427	spin_lock(&c->erase_completion_lock);
428
429	new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
430
431	if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
432		/* If it lives on the dirty_list, jffs2_reserve_space will put it there */
433		D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
434			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
435		if (jffs2_wbuf_dirty(c)) {
436			/* Flush the last write in the block if it's outstanding */
437			spin_unlock(&c->erase_completion_lock);
438			jffs2_flush_wbuf_pad(c);
439			spin_lock(&c->erase_completion_lock);
440		}
441
442		list_add_tail(&jeb->list, &c->clean_list);
443		c->nextblock = NULL;
444	}
445	jffs2_dbg_acct_sanity_check_nolock(c,jeb);
446	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
447
448	spin_unlock(&c->erase_completion_lock);
449
450	return new;
451}
452
453
454void jffs2_complete_reservation(struct jffs2_sb_info *c)
455{
456	D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
457	jffs2_garbage_collect_trigger(c);
458	up(&c->alloc_sem);
459}
460
461static inline int on_list(struct list_head *obj, struct list_head *head)
462{
463	struct list_head *this;
464
465	list_for_each(this, head) {
466		if (this == obj) {
467			D1(printk("%p is on list at %p\n", obj, head));
468			return 1;
469
470		}
471	}
472	return 0;
473}
474
475void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
476{
477	struct jffs2_eraseblock *jeb;
478	int blocknr;
479	struct jffs2_unknown_node n;
480	int ret, addedsize;
481	size_t retlen;
482	uint32_t freed_len;
483
484	if(unlikely(!ref)) {
485		printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
486		return;
487	}
488	if (ref_obsolete(ref)) {
489		D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
490		return;
491	}
492	blocknr = ref->flash_offset / c->sector_size;
493	if (blocknr >= c->nr_blocks) {
494		printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
495		BUG();
496	}
497	jeb = &c->blocks[blocknr];
498
499	if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
500	    !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
501		/* Hm. This may confuse static lock analysis. If any of the above
502		   three conditions is false, we're going to return from this
503		   function without actually obliterating any nodes or freeing
504		   any jffs2_raw_node_refs. So we don't need to stop erases from
505		   happening, or protect against people holding an obsolete
506		   jffs2_raw_node_ref without the erase_completion_lock. */
507		down(&c->erase_free_sem);
508	}
509
510	spin_lock(&c->erase_completion_lock);
511
512	freed_len = ref_totlen(c, jeb, ref);
513
514	if (ref_flags(ref) == REF_UNCHECKED) {
515		D1(if (unlikely(jeb->unchecked_size < freed_len)) {
516			printk(KERN_NOTICE "raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n",
517			       freed_len, blocknr, ref->flash_offset, jeb->used_size);
518			BUG();
519		})
520		D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
521		jeb->unchecked_size -= freed_len;
522		c->unchecked_size -= freed_len;
523	} else {
524		D1(if (unlikely(jeb->used_size < freed_len)) {
525			printk(KERN_NOTICE "raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
526			       freed_len, blocknr, ref->flash_offset, jeb->used_size);
527			BUG();
528		})
529		D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
530		jeb->used_size -= freed_len;
531		c->used_size -= freed_len;
532	}
533
534	// Take care, that wasted size is taken into concern
535	if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
536		D1(printk("Dirtying\n"));
537		addedsize = freed_len;
538		jeb->dirty_size += freed_len;
539		c->dirty_size += freed_len;
540
541		/* Convert wasted space to dirty, if not a bad block */
542		if (jeb->wasted_size) {
543			if (on_list(&jeb->list, &c->bad_used_list)) {
544				D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
545					  jeb->offset));
546				addedsize = 0; /* To fool the refiling code later */
547			} else {
548				D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
549					  jeb->wasted_size, jeb->offset));
550				addedsize += jeb->wasted_size;
551				jeb->dirty_size += jeb->wasted_size;
552				c->dirty_size += jeb->wasted_size;
553				c->wasted_size -= jeb->wasted_size;
554				jeb->wasted_size = 0;
555			}
556		}
557	} else {
558		D1(printk("Wasting\n"));
559		addedsize = 0;
560		jeb->wasted_size += freed_len;
561		c->wasted_size += freed_len;
562	}
563	ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
564
565	jffs2_dbg_acct_sanity_check_nolock(c, jeb);
566	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
567
568	if (c->flags & JFFS2_SB_FLAG_SCANNING) {
569		/* Flash scanning is in progress. Don't muck about with the block
570		   lists because they're not ready yet, and don't actually
571		   obliterate nodes that look obsolete. If they weren't
572		   marked obsolete on the flash at the time they _became_
573		   obsolete, there was probably a reason for that. */
574		spin_unlock(&c->erase_completion_lock);
575		/* We didn't lock the erase_free_sem */
576		return;
577	}
578
579	if (jeb == c->nextblock) {
580		D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
581	} else if (!jeb->used_size && !jeb->unchecked_size) {
582		if (jeb == c->gcblock) {
583			D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
584			c->gcblock = NULL;
585		} else {
586			D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
587			list_del(&jeb->list);
588		}
589		if (jffs2_wbuf_dirty(c)) {
590			D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
591			list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
592		} else {
593			if (jiffies & 127) {
594				/* Most of the time, we just erase it immediately. Otherwise we
595				   spend ages scanning it on mount, etc. */
596				D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
597				list_add_tail(&jeb->list, &c->erase_pending_list);
598				c->nr_erasing_blocks++;
599				jffs2_erase_pending_trigger(c);
600			} else {
601				/* Sometimes, however, we leave it elsewhere so it doesn't get
602				   immediately reused, and we spread the load a bit. */
603				D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
604				list_add_tail(&jeb->list, &c->erasable_list);
605			}
606		}
607		D1(printk(KERN_DEBUG "Done OK\n"));
608	} else if (jeb == c->gcblock) {
609		D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
610	} else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
611		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
612		list_del(&jeb->list);
613		D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
614		list_add_tail(&jeb->list, &c->dirty_list);
615	} else if (VERYDIRTY(c, jeb->dirty_size) &&
616		   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
617		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
618		list_del(&jeb->list);
619		D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
620		list_add_tail(&jeb->list, &c->very_dirty_list);
621	} else {
622		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
623			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
624	}
625
626	spin_unlock(&c->erase_completion_lock);
627
628	if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
629		(c->flags & JFFS2_SB_FLAG_BUILDING)) {
630		/* We didn't lock the erase_free_sem */
631		return;
632	}
633
634	/* The erase_free_sem is locked, and has been since before we marked the node obsolete
635	   and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
636	   the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
637	   by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
638
639	D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
640	ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
641	if (ret) {
642		printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
643		goto out_erase_sem;
644	}
645	if (retlen != sizeof(n)) {
646		printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
647		goto out_erase_sem;
648	}
649	if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
650		printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
651		goto out_erase_sem;
652	}
653	if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
654		D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
655		goto out_erase_sem;
656	}
657	n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
658	ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
659	if (ret) {
660		printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
661		goto out_erase_sem;
662	}
663	if (retlen != sizeof(n)) {
664		printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
665		goto out_erase_sem;
666	}
667
668	/* Nodes which have been marked obsolete no longer need to be
669	   associated with any inode. Remove them from the per-inode list.
670
671	   Note we can't do this for NAND at the moment because we need
672	   obsolete dirent nodes to stay on the lists, because of the
673	   horridness in jffs2_garbage_collect_deletion_dirent(). Also
674	   because we delete the inocache, and on NAND we need that to
675	   stay around until all the nodes are actually erased, in order
676	   to stop us from giving the same inode number to another newly
677	   created inode. */
678	if (ref->next_in_ino) {
679		struct jffs2_inode_cache *ic;
680		struct jffs2_raw_node_ref **p;
681
682		spin_lock(&c->erase_completion_lock);
683
684		ic = jffs2_raw_ref_to_ic(ref);
685		for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
686			;
687
688		*p = ref->next_in_ino;
689		ref->next_in_ino = NULL;
690
691		switch (ic->class) {
692#ifdef CONFIG_JFFS2_FS_XATTR
693			case RAWNODE_CLASS_XATTR_DATUM:
694				jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
695				break;
696			case RAWNODE_CLASS_XATTR_REF:
697				jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
698				break;
699#endif
700			default:
701				if (ic->nodes == (void *)ic && ic->nlink == 0)
702					jffs2_del_ino_cache(c, ic);
703				break;
704		}
705		spin_unlock(&c->erase_completion_lock);
706	}
707
708 out_erase_sem:
709	up(&c->erase_free_sem);
710}
711
712int jffs2_thread_should_wake(struct jffs2_sb_info *c)
713{
714	int ret = 0;
715	uint32_t dirty;
716
717	if (c->unchecked_size) {
718		D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
719			  c->unchecked_size, c->checked_ino));
720		return 1;
721	}
722
723	/* dirty_size contains blocks on erase_pending_list
724	 * those blocks are counted in c->nr_erasing_blocks.
725	 * If one block is actually erased, it is not longer counted as dirty_space
726	 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
727	 * with c->nr_erasing_blocks * c->sector_size again.
728	 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
729	 * This helps us to force gc and pick eventually a clean block to spread the load.
730	 */
731	dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
732
733	if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
734			(dirty > c->nospc_dirty_size))
735		ret = 1;
736
737	D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x: %s\n",
738		  c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, ret?"yes":"no"));
739
740	return ret;
741}
742