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