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/mtd/mtd.h>
 16#include <linux/compiler.h>
 17#include <linux/sched/signal.h>
 18#include "nodelist.h"
 19#include "debug.h"
 20
 21/*
 22 * Check whether the user is allowed to write.
 23 */
 24static int jffs2_rp_can_write(struct jffs2_sb_info *c)
 25{
 26	uint32_t avail;
 27	struct jffs2_mount_opts *opts = &c->mount_opts;
 28
 29	avail = c->dirty_size + c->free_size + c->unchecked_size +
 30		c->erasing_size - c->resv_blocks_write * c->sector_size
 31		- c->nospc_dirty_size;
 32
 33	if (avail < 2 * opts->rp_size)
 34		jffs2_dbg(1, "rpsize %u, dirty_size %u, free_size %u, "
 35			  "erasing_size %u, unchecked_size %u, "
 36			  "nr_erasing_blocks %u, avail %u, resrv %u\n",
 37			  opts->rp_size, c->dirty_size, c->free_size,
 38			  c->erasing_size, c->unchecked_size,
 39			  c->nr_erasing_blocks, avail, c->nospc_dirty_size);
 40
 41	if (avail > opts->rp_size)
 42		return 1;
 43
 44	/* Always allow root */
 45	if (capable(CAP_SYS_RESOURCE))
 46		return 1;
 47
 48	jffs2_dbg(1, "forbid writing\n");
 49	return 0;
 50}
 51
 52/**
 53 *	jffs2_reserve_space - request physical space to write nodes to flash
 54 *	@c: superblock info
 55 *	@minsize: Minimum acceptable size of allocation
 56 *	@len: Returned value of allocation length
 57 *	@prio: Allocation type - ALLOC_{NORMAL,DELETION}
 58 *
 59 *	Requests a block of physical space on the flash. Returns zero for success
 60 *	and puts 'len' into the appropriate place, or returns -ENOSPC or other 
 61 *	error if appropriate. Doesn't return len since that's 
 62 *
 63 *	If it returns zero, jffs2_reserve_space() also downs the per-filesystem
 64 *	allocation semaphore, to prevent more than one allocation from being
 65 *	active at any time. The semaphore is later released by jffs2_commit_allocation()
 66 *
 67 *	jffs2_reserve_space() may trigger garbage collection in order to make room
 68 *	for the requested allocation.
 69 */
 70
 71static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
 72				  uint32_t *len, uint32_t sumsize);
 73
 74int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 75			uint32_t *len, int prio, uint32_t sumsize)
 76{
 77	int ret = -EAGAIN;
 78	int blocksneeded = c->resv_blocks_write;
 79	/* align it */
 80	minsize = PAD(minsize);
 81
 82	jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
 83	mutex_lock(&c->alloc_sem);
 84
 85	jffs2_dbg(1, "%s(): alloc sem got\n", __func__);
 86
 87	spin_lock(&c->erase_completion_lock);
 88
 89	/*
 90	 * Check if the free space is greater then size of the reserved pool.
 91	 * If not, only allow root to proceed with writing.
 92	 */
 93	if (prio != ALLOC_DELETION && !jffs2_rp_can_write(c)) {
 94		ret = -ENOSPC;
 95		goto out;
 96	}
 97
 98	/* this needs a little more thought (true <tglx> :)) */
 99	while(ret == -EAGAIN) {
100		while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
101			uint32_t dirty, avail;
102
103			/* calculate real dirty size
104			 * dirty_size contains blocks on erase_pending_list
105			 * those blocks are counted in c->nr_erasing_blocks.
106			 * If one block is actually erased, it is not longer counted as dirty_space
107			 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
108			 * with c->nr_erasing_blocks * c->sector_size again.
109			 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
110			 * This helps us to force gc and pick eventually a clean block to spread the load.
111			 * We add unchecked_size here, as we hopefully will find some space to use.
112			 * This will affect the sum only once, as gc first finishes checking
113			 * of nodes.
114			 */
115			dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
116			if (dirty < c->nospc_dirty_size) {
117				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
118					jffs2_dbg(1, "%s(): Low on dirty space to GC, but it's a deletion. Allowing...\n",
119						  __func__);
120					break;
121				}
122				jffs2_dbg(1, "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
123					  dirty, c->unchecked_size,
124					  c->sector_size);
125
126				spin_unlock(&c->erase_completion_lock);
127				mutex_unlock(&c->alloc_sem);
128				return -ENOSPC;
129			}
130
131			/* Calc possibly available space. Possibly available means that we
132			 * don't know, if unchecked size contains obsoleted nodes, which could give us some
133			 * more usable space. This will affect the sum only once, as gc first finishes checking
134			 * of nodes.
135			 + Return -ENOSPC, if the maximum possibly available space is less or equal than
136			 * blocksneeded * sector_size.
137			 * This blocks endless gc looping on a filesystem, which is nearly full, even if
138			 * the check above passes.
139			 */
140			avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
141			if ( (avail / c->sector_size) <= blocksneeded) {
142				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
143					jffs2_dbg(1, "%s(): Low on possibly available space, but it's a deletion. Allowing...\n",
144						  __func__);
145					break;
146				}
147
148				jffs2_dbg(1, "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
149					  avail, blocksneeded * c->sector_size);
150				spin_unlock(&c->erase_completion_lock);
151				mutex_unlock(&c->alloc_sem);
152				return -ENOSPC;
153			}
154
155			mutex_unlock(&c->alloc_sem);
156
157			jffs2_dbg(1, "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",
158				  c->nr_free_blocks, c->nr_erasing_blocks,
159				  c->free_size, c->dirty_size, c->wasted_size,
160				  c->used_size, c->erasing_size, c->bad_size,
161				  c->free_size + c->dirty_size +
162				  c->wasted_size + c->used_size +
163				  c->erasing_size + c->bad_size,
164				  c->flash_size);
165			spin_unlock(&c->erase_completion_lock);
166
167			ret = jffs2_garbage_collect_pass(c);
168
169			if (ret == -EAGAIN) {
170				spin_lock(&c->erase_completion_lock);
171				if (c->nr_erasing_blocks &&
172				    list_empty(&c->erase_pending_list) &&
173				    list_empty(&c->erase_complete_list)) {
174					DECLARE_WAITQUEUE(wait, current);
175					set_current_state(TASK_UNINTERRUPTIBLE);
176					add_wait_queue(&c->erase_wait, &wait);
177					jffs2_dbg(1, "%s waiting for erase to complete\n",
178						  __func__);
179					spin_unlock(&c->erase_completion_lock);
180
181					schedule();
182					remove_wait_queue(&c->erase_wait, &wait);
183				} else
184					spin_unlock(&c->erase_completion_lock);
185			} else if (ret)
186				return ret;
187
188			cond_resched();
189
190			if (signal_pending(current))
191				return -EINTR;
192
193			mutex_lock(&c->alloc_sem);
194			spin_lock(&c->erase_completion_lock);
195		}
196
197		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
198		if (ret) {
199			jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret);
200		}
201	}
202
203out:
204	spin_unlock(&c->erase_completion_lock);
205	if (!ret)
206		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
207	if (ret)
208		mutex_unlock(&c->alloc_sem);
209	return ret;
210}
211
212int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
213			   uint32_t *len, uint32_t sumsize)
214{
215	int ret;
216	minsize = PAD(minsize);
217
218	jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
219
220	while (true) {
221		spin_lock(&c->erase_completion_lock);
222		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
223		if (ret) {
224			jffs2_dbg(1, "%s(): looping, ret is %d\n",
225				  __func__, ret);
226		}
227		spin_unlock(&c->erase_completion_lock);
228
229		if (ret == -EAGAIN)
230			cond_resched();
231		else
232			break;
233	}
 
234	if (!ret)
235		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
236
237	return ret;
238}
239
240
241/* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
242
243static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
244{
245
246	if (c->nextblock == NULL) {
247		jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n",
248			  __func__, jeb->offset);
249		return;
250	}
251	/* Check, if we have a dirty block now, or if it was dirty already */
252	if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
253		c->dirty_size += jeb->wasted_size;
254		c->wasted_size -= jeb->wasted_size;
255		jeb->dirty_size += jeb->wasted_size;
256		jeb->wasted_size = 0;
257		if (VERYDIRTY(c, jeb->dirty_size)) {
258			jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
259				  jeb->offset, jeb->free_size, jeb->dirty_size,
260				  jeb->used_size);
261			list_add_tail(&jeb->list, &c->very_dirty_list);
262		} else {
263			jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
264				  jeb->offset, jeb->free_size, jeb->dirty_size,
265				  jeb->used_size);
266			list_add_tail(&jeb->list, &c->dirty_list);
267		}
268	} else {
269		jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
270			  jeb->offset, jeb->free_size, jeb->dirty_size,
271			  jeb->used_size);
272		list_add_tail(&jeb->list, &c->clean_list);
273	}
274	c->nextblock = NULL;
275
276}
277
278/* Select a new jeb for nextblock */
279
280static int jffs2_find_nextblock(struct jffs2_sb_info *c)
281{
282	struct list_head *next;
283
284	/* Take the next block off the 'free' list */
285
286	if (list_empty(&c->free_list)) {
287
288		if (!c->nr_erasing_blocks &&
289			!list_empty(&c->erasable_list)) {
290			struct jffs2_eraseblock *ejeb;
291
292			ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
293			list_move_tail(&ejeb->list, &c->erase_pending_list);
294			c->nr_erasing_blocks++;
295			jffs2_garbage_collect_trigger(c);
296			jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n",
297				  __func__, ejeb->offset);
298		}
299
300		if (!c->nr_erasing_blocks &&
301			!list_empty(&c->erasable_pending_wbuf_list)) {
302			jffs2_dbg(1, "%s(): Flushing write buffer\n",
303				  __func__);
304			/* c->nextblock is NULL, no update to c->nextblock allowed */
305			spin_unlock(&c->erase_completion_lock);
306			jffs2_flush_wbuf_pad(c);
307			spin_lock(&c->erase_completion_lock);
308			/* Have another go. It'll be on the erasable_list now */
309			return -EAGAIN;
310		}
311
312		if (!c->nr_erasing_blocks) {
313			/* Ouch. We're in GC, or we wouldn't have got here.
314			   And there's no space left. At all. */
315			pr_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",
316				c->nr_erasing_blocks, c->nr_free_blocks,
317				list_empty(&c->erasable_list) ? "yes" : "no",
318				list_empty(&c->erasing_list) ? "yes" : "no",
319				list_empty(&c->erase_pending_list) ? "yes" : "no");
320			return -ENOSPC;
321		}
322
323		spin_unlock(&c->erase_completion_lock);
324		/* Don't wait for it; just erase one right now */
325		jffs2_erase_pending_blocks(c, 1);
326		spin_lock(&c->erase_completion_lock);
327
328		/* An erase may have failed, decreasing the
329		   amount of free space available. So we must
330		   restart from the beginning */
331		return -EAGAIN;
332	}
333
334	next = c->free_list.next;
335	list_del(next);
336	c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
337	c->nr_free_blocks--;
338
339	jffs2_sum_reset_collected(c->summary); /* reset collected summary */
340
341#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
342	/* adjust write buffer offset, else we get a non contiguous write bug */
343	if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
344		c->wbuf_ofs = 0xffffffff;
345#endif
346
347	jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
348		  __func__, c->nextblock->offset);
349
350	return 0;
351}
352
353/* Called with alloc sem _and_ erase_completion_lock */
354static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
355				  uint32_t *len, uint32_t sumsize)
356{
357	struct jffs2_eraseblock *jeb = c->nextblock;
358	uint32_t reserved_size;				/* for summary information at the end of the jeb */
359	int ret;
360
361 restart:
362	reserved_size = 0;
363
364	if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
365							/* NOSUM_SIZE means not to generate summary */
366
367		if (jeb) {
368			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
369			dbg_summary("minsize=%d , jeb->free=%d ,"
370						"summary->size=%d , sumsize=%d\n",
371						minsize, jeb->free_size,
372						c->summary->sum_size, sumsize);
373		}
374
375		/* Is there enough space for writing out the current node, or we have to
376		   write out summary information now, close this jeb and select new nextblock? */
377		if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
378					JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
379
380			/* Has summary been disabled for this jeb? */
381			if (jffs2_sum_is_disabled(c->summary)) {
382				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
383				goto restart;
384			}
385
386			/* Writing out the collected summary information */
387			dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
388			ret = jffs2_sum_write_sumnode(c);
389
390			if (ret)
391				return ret;
392
393			if (jffs2_sum_is_disabled(c->summary)) {
394				/* jffs2_write_sumnode() couldn't write out the summary information
395				   diabling summary for this jeb and free the collected information
396				 */
397				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
398				goto restart;
399			}
400
401			jffs2_close_nextblock(c, jeb);
402			jeb = NULL;
403			/* keep always valid value in reserved_size */
404			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
405		}
406	} else {
407		if (jeb && minsize > jeb->free_size) {
408			uint32_t waste;
409
410			/* Skip the end of this block and file it as having some dirty space */
411			/* If there's a pending write to it, flush now */
412
413			if (jffs2_wbuf_dirty(c)) {
414				spin_unlock(&c->erase_completion_lock);
415				jffs2_dbg(1, "%s(): Flushing write buffer\n",
416					  __func__);
417				jffs2_flush_wbuf_pad(c);
418				spin_lock(&c->erase_completion_lock);
419				jeb = c->nextblock;
420				goto restart;
421			}
422
423			spin_unlock(&c->erase_completion_lock);
424
425			ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
426
 
427			/* Just lock it again and continue. Nothing much can change because
428			   we hold c->alloc_sem anyway. In fact, it's not entirely clear why
429			   we hold c->erase_completion_lock in the majority of this function...
430			   but that's a question for another (more caffeine-rich) day. */
431			spin_lock(&c->erase_completion_lock);
432
433			if (ret)
434				return ret;
435
436			waste = jeb->free_size;
437			jffs2_link_node_ref(c, jeb,
438					    (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
439					    waste, NULL);
440			/* FIXME: that made it count as dirty. Convert to wasted */
441			jeb->dirty_size -= waste;
442			c->dirty_size -= waste;
443			jeb->wasted_size += waste;
444			c->wasted_size += waste;
445
446			jffs2_close_nextblock(c, jeb);
447			jeb = NULL;
448		}
449	}
450
451	if (!jeb) {
452
453		ret = jffs2_find_nextblock(c);
454		if (ret)
455			return ret;
456
457		jeb = c->nextblock;
458
459		if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
460			pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n",
461				jeb->offset, jeb->free_size);
462			goto restart;
463		}
464	}
465	/* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
466	   enough space */
467	*len = jeb->free_size - reserved_size;
468
469	if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
470	    !jeb->first_node->next_in_ino) {
471		/* Only node in it beforehand was a CLEANMARKER node (we think).
472		   So mark it obsolete now that there's going to be another node
473		   in the block. This will reduce used_size to zero but We've
474		   already set c->nextblock so that jffs2_mark_node_obsolete()
475		   won't try to refile it to the dirty_list.
476		*/
477		spin_unlock(&c->erase_completion_lock);
478		jffs2_mark_node_obsolete(c, jeb->first_node);
479		spin_lock(&c->erase_completion_lock);
480	}
481
482	jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n",
483		  __func__,
484		  *len, jeb->offset + (c->sector_size - jeb->free_size));
485	return 0;
486}
487
488/**
489 *	jffs2_add_physical_node_ref - add a physical node reference to the list
490 *	@c: superblock info
491 *	@new: new node reference to add
492 *	@len: length of this physical node
493 *
494 *	Should only be used to report nodes for which space has been allocated
495 *	by jffs2_reserve_space.
496 *
497 *	Must be called with the alloc_sem held.
498 */
499
500struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
501						       uint32_t ofs, uint32_t len,
502						       struct jffs2_inode_cache *ic)
503{
504	struct jffs2_eraseblock *jeb;
505	struct jffs2_raw_node_ref *new;
506
507	jeb = &c->blocks[ofs / c->sector_size];
508
509	jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n",
510		  __func__, ofs & ~3, ofs & 3, len);
511#if 1
512	/* Allow non-obsolete nodes only to be added at the end of c->nextblock, 
513	   if c->nextblock is set. Note that wbuf.c will file obsolete nodes
514	   even after refiling c->nextblock */
515	if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
516	    && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
517		pr_warn("argh. node added in wrong place at 0x%08x(%d)\n",
518			ofs & ~3, ofs & 3);
519		if (c->nextblock)
520			pr_warn("nextblock 0x%08x", c->nextblock->offset);
521		else
522			pr_warn("No nextblock");
523		pr_cont(", expected at %08x\n",
524			jeb->offset + (c->sector_size - jeb->free_size));
525		return ERR_PTR(-EINVAL);
526	}
527#endif
528	spin_lock(&c->erase_completion_lock);
529
530	new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
531
532	if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
533		/* If it lives on the dirty_list, jffs2_reserve_space will put it there */
534		jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
535			  jeb->offset, jeb->free_size, jeb->dirty_size,
536			  jeb->used_size);
537		if (jffs2_wbuf_dirty(c)) {
538			/* Flush the last write in the block if it's outstanding */
539			spin_unlock(&c->erase_completion_lock);
540			jffs2_flush_wbuf_pad(c);
541			spin_lock(&c->erase_completion_lock);
542		}
543
544		list_add_tail(&jeb->list, &c->clean_list);
545		c->nextblock = NULL;
546	}
547	jffs2_dbg_acct_sanity_check_nolock(c,jeb);
548	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
549
550	spin_unlock(&c->erase_completion_lock);
551
552	return new;
553}
554
555
556void jffs2_complete_reservation(struct jffs2_sb_info *c)
557{
558	jffs2_dbg(1, "jffs2_complete_reservation()\n");
559	spin_lock(&c->erase_completion_lock);
560	jffs2_garbage_collect_trigger(c);
561	spin_unlock(&c->erase_completion_lock);
562	mutex_unlock(&c->alloc_sem);
563}
564
565static inline int on_list(struct list_head *obj, struct list_head *head)
566{
567	struct list_head *this;
568
569	list_for_each(this, head) {
570		if (this == obj) {
571			jffs2_dbg(1, "%p is on list at %p\n", obj, head);
572			return 1;
573
574		}
575	}
576	return 0;
577}
578
579void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
580{
581	struct jffs2_eraseblock *jeb;
582	int blocknr;
583	struct jffs2_unknown_node n;
584	int ret, addedsize;
585	size_t retlen;
586	uint32_t freed_len;
587
588	if(unlikely(!ref)) {
589		pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
590		return;
591	}
592	if (ref_obsolete(ref)) {
593		jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n",
594			  __func__, ref_offset(ref));
595		return;
596	}
597	blocknr = ref->flash_offset / c->sector_size;
598	if (blocknr >= c->nr_blocks) {
599		pr_notice("raw node at 0x%08x is off the end of device!\n",
600			  ref->flash_offset);
601		BUG();
602	}
603	jeb = &c->blocks[blocknr];
604
605	if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
606	    !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
607		/* Hm. This may confuse static lock analysis. If any of the above
608		   three conditions is false, we're going to return from this
609		   function without actually obliterating any nodes or freeing
610		   any jffs2_raw_node_refs. So we don't need to stop erases from
611		   happening, or protect against people holding an obsolete
612		   jffs2_raw_node_ref without the erase_completion_lock. */
613		mutex_lock(&c->erase_free_sem);
614	}
615
616	spin_lock(&c->erase_completion_lock);
617
618	freed_len = ref_totlen(c, jeb, ref);
619
620	if (ref_flags(ref) == REF_UNCHECKED) {
621		D1(if (unlikely(jeb->unchecked_size < freed_len)) {
622				pr_notice("raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n",
623					  freed_len, blocknr,
624					  ref->flash_offset, jeb->used_size);
625			BUG();
626		})
627			jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n",
628				  ref_offset(ref), freed_len);
629		jeb->unchecked_size -= freed_len;
630		c->unchecked_size -= freed_len;
631	} else {
632		D1(if (unlikely(jeb->used_size < freed_len)) {
633				pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
634					  freed_len, blocknr,
635					  ref->flash_offset, jeb->used_size);
636			BUG();
637		})
638			jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ",
639				  ref_offset(ref), freed_len);
640		jeb->used_size -= freed_len;
641		c->used_size -= freed_len;
642	}
643
644	// Take care, that wasted size is taken into concern
645	if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
646		jffs2_dbg(1, "Dirtying\n");
647		addedsize = freed_len;
648		jeb->dirty_size += freed_len;
649		c->dirty_size += freed_len;
650
651		/* Convert wasted space to dirty, if not a bad block */
652		if (jeb->wasted_size) {
653			if (on_list(&jeb->list, &c->bad_used_list)) {
654				jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n",
655					  jeb->offset);
656				addedsize = 0; /* To fool the refiling code later */
657			} else {
658				jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n",
659					  jeb->wasted_size, jeb->offset);
660				addedsize += jeb->wasted_size;
661				jeb->dirty_size += jeb->wasted_size;
662				c->dirty_size += jeb->wasted_size;
663				c->wasted_size -= jeb->wasted_size;
664				jeb->wasted_size = 0;
665			}
666		}
667	} else {
668		jffs2_dbg(1, "Wasting\n");
669		addedsize = 0;
670		jeb->wasted_size += freed_len;
671		c->wasted_size += freed_len;
672	}
673	ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
674
675	jffs2_dbg_acct_sanity_check_nolock(c, jeb);
676	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
677
678	if (c->flags & JFFS2_SB_FLAG_SCANNING) {
679		/* Flash scanning is in progress. Don't muck about with the block
680		   lists because they're not ready yet, and don't actually
681		   obliterate nodes that look obsolete. If they weren't
682		   marked obsolete on the flash at the time they _became_
683		   obsolete, there was probably a reason for that. */
684		spin_unlock(&c->erase_completion_lock);
685		/* We didn't lock the erase_free_sem */
686		return;
687	}
688
689	if (jeb == c->nextblock) {
690		jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n",
691			  jeb->offset);
692	} else if (!jeb->used_size && !jeb->unchecked_size) {
693		if (jeb == c->gcblock) {
694			jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n",
695				  jeb->offset);
696			c->gcblock = NULL;
697		} else {
698			jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n",
699				  jeb->offset);
700			list_del(&jeb->list);
701		}
702		if (jffs2_wbuf_dirty(c)) {
703			jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n");
704			list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
705		} else {
706			if (jiffies & 127) {
707				/* Most of the time, we just erase it immediately. Otherwise we
708				   spend ages scanning it on mount, etc. */
709				jffs2_dbg(1, "...and adding to erase_pending_list\n");
710				list_add_tail(&jeb->list, &c->erase_pending_list);
711				c->nr_erasing_blocks++;
712				jffs2_garbage_collect_trigger(c);
713			} else {
714				/* Sometimes, however, we leave it elsewhere so it doesn't get
715				   immediately reused, and we spread the load a bit. */
716				jffs2_dbg(1, "...and adding to erasable_list\n");
717				list_add_tail(&jeb->list, &c->erasable_list);
718			}
719		}
720		jffs2_dbg(1, "Done OK\n");
721	} else if (jeb == c->gcblock) {
722		jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n",
723			  jeb->offset);
724	} else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
725		jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n",
726			  jeb->offset);
727		list_del(&jeb->list);
728		jffs2_dbg(1, "...and adding to dirty_list\n");
729		list_add_tail(&jeb->list, &c->dirty_list);
730	} else if (VERYDIRTY(c, jeb->dirty_size) &&
731		   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
732		jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n",
733			  jeb->offset);
734		list_del(&jeb->list);
735		jffs2_dbg(1, "...and adding to very_dirty_list\n");
736		list_add_tail(&jeb->list, &c->very_dirty_list);
737	} else {
738		jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
739			  jeb->offset, jeb->free_size, jeb->dirty_size,
740			  jeb->used_size);
741	}
742
743	spin_unlock(&c->erase_completion_lock);
744
745	if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
746		(c->flags & JFFS2_SB_FLAG_BUILDING)) {
747		/* We didn't lock the erase_free_sem */
748		return;
749	}
750
751	/* The erase_free_sem is locked, and has been since before we marked the node obsolete
752	   and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
753	   the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
754	   by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
755
756	jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n",
757		  ref_offset(ref));
758	ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
759	if (ret) {
760		pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n",
761			ref_offset(ref), ret);
762		goto out_erase_sem;
763	}
764	if (retlen != sizeof(n)) {
765		pr_warn("Short read from obsoleted node at 0x%08x: %zd\n",
766			ref_offset(ref), retlen);
767		goto out_erase_sem;
768	}
769	if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
770		pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n",
771			je32_to_cpu(n.totlen), freed_len);
772		goto out_erase_sem;
773	}
774	if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
775		jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n",
776			  ref_offset(ref), je16_to_cpu(n.nodetype));
777		goto out_erase_sem;
778	}
779	/* XXX FIXME: This is ugly now */
780	n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
781	ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
782	if (ret) {
783		pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n",
784			ref_offset(ref), ret);
785		goto out_erase_sem;
786	}
787	if (retlen != sizeof(n)) {
788		pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n",
789			ref_offset(ref), retlen);
790		goto out_erase_sem;
791	}
792
793	/* Nodes which have been marked obsolete no longer need to be
794	   associated with any inode. Remove them from the per-inode list.
795
796	   Note we can't do this for NAND at the moment because we need
797	   obsolete dirent nodes to stay on the lists, because of the
798	   horridness in jffs2_garbage_collect_deletion_dirent(). Also
799	   because we delete the inocache, and on NAND we need that to
800	   stay around until all the nodes are actually erased, in order
801	   to stop us from giving the same inode number to another newly
802	   created inode. */
803	if (ref->next_in_ino) {
804		struct jffs2_inode_cache *ic;
805		struct jffs2_raw_node_ref **p;
806
807		spin_lock(&c->erase_completion_lock);
808
809		ic = jffs2_raw_ref_to_ic(ref);
810		for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
811			;
812
813		*p = ref->next_in_ino;
814		ref->next_in_ino = NULL;
815
816		switch (ic->class) {
817#ifdef CONFIG_JFFS2_FS_XATTR
818			case RAWNODE_CLASS_XATTR_DATUM:
819				jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
820				break;
821			case RAWNODE_CLASS_XATTR_REF:
822				jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
823				break;
824#endif
825			default:
826				if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
827					jffs2_del_ino_cache(c, ic);
828				break;
829		}
830		spin_unlock(&c->erase_completion_lock);
831	}
832
833 out_erase_sem:
834	mutex_unlock(&c->erase_free_sem);
835}
836
837int jffs2_thread_should_wake(struct jffs2_sb_info *c)
838{
839	int ret = 0;
840	uint32_t dirty;
841	int nr_very_dirty = 0;
842	struct jffs2_eraseblock *jeb;
843
844	if (!list_empty(&c->erase_complete_list) ||
845	    !list_empty(&c->erase_pending_list))
846		return 1;
847
848	if (c->unchecked_size) {
849		jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, check_ino #%d\n",
850			  c->unchecked_size, c->check_ino);
851		return 1;
852	}
853
854	/* dirty_size contains blocks on erase_pending_list
855	 * those blocks are counted in c->nr_erasing_blocks.
856	 * If one block is actually erased, it is not longer counted as dirty_space
857	 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
858	 * with c->nr_erasing_blocks * c->sector_size again.
859	 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
860	 * This helps us to force gc and pick eventually a clean block to spread the load.
861	 */
862	dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
863
864	if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
865			(dirty > c->nospc_dirty_size))
866		ret = 1;
867
868	list_for_each_entry(jeb, &c->very_dirty_list, list) {
869		nr_very_dirty++;
870		if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
871			ret = 1;
872			/* In debug mode, actually go through and count them all */
873			D1(continue);
874			break;
875		}
876	}
877
878	jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
879		  __func__, c->nr_free_blocks, c->nr_erasing_blocks,
880		  c->dirty_size, nr_very_dirty, ret ? "yes" : "no");
881
882	return ret;
883}