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/mtd/mtd.h>
14 #include <linux/compiler.h>
15 #include <linux/sched.h> /* For cond_resched() */
16 #include "nodelist.h"
17 #include "debug.h"
18 
19 /**
20  *	jffs2_reserve_space - request physical space to write nodes to flash
21  *	@c: superblock info
22  *	@minsize: Minimum acceptable size of allocation
23  *	@len: Returned value of allocation length
24  *	@prio: Allocation type - ALLOC_{NORMAL,DELETION}
25  *
26  *	Requests a block of physical space on the flash. Returns zero for success
27  *	and puts 'len' into the appropriate place, or returns -ENOSPC or other
28  *	error if appropriate. Doesn't return len since that's
29  *
30  *	If it returns zero, jffs2_reserve_space() also downs the per-filesystem
31  *	allocation semaphore, to prevent more than one allocation from being
32  *	active at any time. The semaphore is later released by jffs2_commit_allocation()
33  *
34  *	jffs2_reserve_space() may trigger garbage collection in order to make room
35  *	for the requested allocation.
36  */
37 
38 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
39 				  uint32_t *len, uint32_t sumsize);
40 
jffs2_reserve_space(struct jffs2_sb_info * c,uint32_t minsize,uint32_t * len,int prio,uint32_t sumsize)41 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
42 			uint32_t *len, int prio, uint32_t sumsize)
43 {
44 	int ret = -EAGAIN;
45 	int blocksneeded = c->resv_blocks_write;
46 	/* align it */
47 	minsize = PAD(minsize);
48 
49 	D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
50 	mutex_lock(&c->alloc_sem);
51 
52 	D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
53 
54 	spin_lock(&c->erase_completion_lock);
55 
56 	/* this needs a little more thought (true <tglx> :)) */
57 	while(ret == -EAGAIN) {
58 		while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
59 			uint32_t dirty, avail;
60 
61 			/* calculate real dirty size
62 			 * dirty_size contains blocks on erase_pending_list
63 			 * those blocks are counted in c->nr_erasing_blocks.
64 			 * If one block is actually erased, it is not longer counted as dirty_space
65 			 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
66 			 * with c->nr_erasing_blocks * c->sector_size again.
67 			 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
68 			 * This helps us to force gc and pick eventually a clean block to spread the load.
69 			 * We add unchecked_size here, as we hopefully will find some space to use.
70 			 * This will affect the sum only once, as gc first finishes checking
71 			 * of nodes.
72 			 */
73 			dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
74 			if (dirty < c->nospc_dirty_size) {
75 				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
76 					D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
77 					break;
78 				}
79 				D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
80 					  dirty, c->unchecked_size, c->sector_size));
81 
82 				spin_unlock(&c->erase_completion_lock);
83 				mutex_unlock(&c->alloc_sem);
84 				return -ENOSPC;
85 			}
86 
87 			/* Calc possibly available space. Possibly available means that we
88 			 * don't know, if unchecked size contains obsoleted nodes, which could give us some
89 			 * more usable space. This will affect the sum only once, as gc first finishes checking
90 			 * of nodes.
91 			 + Return -ENOSPC, if the maximum possibly available space is less or equal than
92 			 * blocksneeded * sector_size.
93 			 * This blocks endless gc looping on a filesystem, which is nearly full, even if
94 			 * the check above passes.
95 			 */
96 			avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
97 			if ( (avail / c->sector_size) <= blocksneeded) {
98 				if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
99 					D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
100 					break;
101 				}
102 
103 				D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
104 					  avail, blocksneeded * c->sector_size));
105 				spin_unlock(&c->erase_completion_lock);
106 				mutex_unlock(&c->alloc_sem);
107 				return -ENOSPC;
108 			}
109 
110 			mutex_unlock(&c->alloc_sem);
111 
112 			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",
113 				  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,
114 				  c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
115 			spin_unlock(&c->erase_completion_lock);
116 
117 			ret = jffs2_garbage_collect_pass(c);
118 
119 			if (ret == -EAGAIN) {
120 				spin_lock(&c->erase_completion_lock);
121 				if (c->nr_erasing_blocks &&
122 				    list_empty(&c->erase_pending_list) &&
123 				    list_empty(&c->erase_complete_list)) {
124 					DECLARE_WAITQUEUE(wait, current);
125 					set_current_state(TASK_UNINTERRUPTIBLE);
126 					add_wait_queue(&c->erase_wait, &wait);
127 					D1(printk(KERN_DEBUG "%s waiting for erase to complete\n", __func__));
128 					spin_unlock(&c->erase_completion_lock);
129 
130 					schedule();
131 				} else
132 					spin_unlock(&c->erase_completion_lock);
133 			} else if (ret)
134 				return ret;
135 
136 			cond_resched();
137 
138 			if (signal_pending(current))
139 				return -EINTR;
140 
141 			mutex_lock(&c->alloc_sem);
142 			spin_lock(&c->erase_completion_lock);
143 		}
144 
145 		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
146 		if (ret) {
147 			D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
148 		}
149 	}
150 	spin_unlock(&c->erase_completion_lock);
151 	if (!ret)
152 		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
153 	if (ret)
154 		mutex_unlock(&c->alloc_sem);
155 	return ret;
156 }
157 
jffs2_reserve_space_gc(struct jffs2_sb_info * c,uint32_t minsize,uint32_t * len,uint32_t sumsize)158 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
159 			   uint32_t *len, uint32_t sumsize)
160 {
161 	int ret = -EAGAIN;
162 	minsize = PAD(minsize);
163 
164 	D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
165 
166 	spin_lock(&c->erase_completion_lock);
167 	while(ret == -EAGAIN) {
168 		ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
169 		if (ret) {
170 			D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
171 		}
172 	}
173 	spin_unlock(&c->erase_completion_lock);
174 	if (!ret)
175 		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
176 
177 	return ret;
178 }
179 
180 
181 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
182 
jffs2_close_nextblock(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb)183 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
184 {
185 
186 	if (c->nextblock == NULL) {
187 		D1(printk(KERN_DEBUG "jffs2_close_nextblock: Erase block at 0x%08x has already been placed in a list\n",
188 		  jeb->offset));
189 		return;
190 	}
191 	/* Check, if we have a dirty block now, or if it was dirty already */
192 	if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
193 		c->dirty_size += jeb->wasted_size;
194 		c->wasted_size -= jeb->wasted_size;
195 		jeb->dirty_size += jeb->wasted_size;
196 		jeb->wasted_size = 0;
197 		if (VERYDIRTY(c, jeb->dirty_size)) {
198 			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",
199 			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
200 			list_add_tail(&jeb->list, &c->very_dirty_list);
201 		} else {
202 			D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
203 			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
204 			list_add_tail(&jeb->list, &c->dirty_list);
205 		}
206 	} else {
207 		D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
208 		  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
209 		list_add_tail(&jeb->list, &c->clean_list);
210 	}
211 	c->nextblock = NULL;
212 
213 }
214 
215 /* Select a new jeb for nextblock */
216 
jffs2_find_nextblock(struct jffs2_sb_info * c)217 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
218 {
219 	struct list_head *next;
220 
221 	/* Take the next block off the 'free' list */
222 
223 	if (list_empty(&c->free_list)) {
224 
225 		if (!c->nr_erasing_blocks &&
226 			!list_empty(&c->erasable_list)) {
227 			struct jffs2_eraseblock *ejeb;
228 
229 			ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
230 			list_move_tail(&ejeb->list, &c->erase_pending_list);
231 			c->nr_erasing_blocks++;
232 			jffs2_garbage_collect_trigger(c);
233 			D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
234 				  ejeb->offset));
235 		}
236 
237 		if (!c->nr_erasing_blocks &&
238 			!list_empty(&c->erasable_pending_wbuf_list)) {
239 			D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
240 			/* c->nextblock is NULL, no update to c->nextblock allowed */
241 			spin_unlock(&c->erase_completion_lock);
242 			jffs2_flush_wbuf_pad(c);
243 			spin_lock(&c->erase_completion_lock);
244 			/* Have another go. It'll be on the erasable_list now */
245 			return -EAGAIN;
246 		}
247 
248 		if (!c->nr_erasing_blocks) {
249 			/* Ouch. We're in GC, or we wouldn't have got here.
250 			   And there's no space left. At all. */
251 			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",
252 				   c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
253 				   list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
254 			return -ENOSPC;
255 		}
256 
257 		spin_unlock(&c->erase_completion_lock);
258 		/* Don't wait for it; just erase one right now */
259 		jffs2_erase_pending_blocks(c, 1);
260 		spin_lock(&c->erase_completion_lock);
261 
262 		/* An erase may have failed, decreasing the
263 		   amount of free space available. So we must
264 		   restart from the beginning */
265 		return -EAGAIN;
266 	}
267 
268 	next = c->free_list.next;
269 	list_del(next);
270 	c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
271 	c->nr_free_blocks--;
272 
273 	jffs2_sum_reset_collected(c->summary); /* reset collected summary */
274 
275 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
276 	/* adjust write buffer offset, else we get a non contiguous write bug */
277 	if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
278 		c->wbuf_ofs = 0xffffffff;
279 #endif
280 
281 	D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
282 
283 	return 0;
284 }
285 
286 /* 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)287 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
288 				  uint32_t *len, uint32_t sumsize)
289 {
290 	struct jffs2_eraseblock *jeb = c->nextblock;
291 	uint32_t reserved_size;				/* for summary information at the end of the jeb */
292 	int ret;
293 
294  restart:
295 	reserved_size = 0;
296 
297 	if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
298 							/* NOSUM_SIZE means not to generate summary */
299 
300 		if (jeb) {
301 			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
302 			dbg_summary("minsize=%d , jeb->free=%d ,"
303 						"summary->size=%d , sumsize=%d\n",
304 						minsize, jeb->free_size,
305 						c->summary->sum_size, sumsize);
306 		}
307 
308 		/* Is there enough space for writing out the current node, or we have to
309 		   write out summary information now, close this jeb and select new nextblock? */
310 		if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
311 					JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
312 
313 			/* Has summary been disabled for this jeb? */
314 			if (jffs2_sum_is_disabled(c->summary)) {
315 				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
316 				goto restart;
317 			}
318 
319 			/* Writing out the collected summary information */
320 			dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
321 			ret = jffs2_sum_write_sumnode(c);
322 
323 			if (ret)
324 				return ret;
325 
326 			if (jffs2_sum_is_disabled(c->summary)) {
327 				/* jffs2_write_sumnode() couldn't write out the summary information
328 				   diabling summary for this jeb and free the collected information
329 				 */
330 				sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
331 				goto restart;
332 			}
333 
334 			jffs2_close_nextblock(c, jeb);
335 			jeb = NULL;
336 			/* keep always valid value in reserved_size */
337 			reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
338 		}
339 	} else {
340 		if (jeb && minsize > jeb->free_size) {
341 			uint32_t waste;
342 
343 			/* Skip the end of this block and file it as having some dirty space */
344 			/* If there's a pending write to it, flush now */
345 
346 			if (jffs2_wbuf_dirty(c)) {
347 				spin_unlock(&c->erase_completion_lock);
348 				D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
349 				jffs2_flush_wbuf_pad(c);
350 				spin_lock(&c->erase_completion_lock);
351 				jeb = c->nextblock;
352 				goto restart;
353 			}
354 
355 			spin_unlock(&c->erase_completion_lock);
356 
357 			ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
358 			if (ret)
359 				return ret;
360 			/* Just lock it again and continue. Nothing much can change because
361 			   we hold c->alloc_sem anyway. In fact, it's not entirely clear why
362 			   we hold c->erase_completion_lock in the majority of this function...
363 			   but that's a question for another (more caffeine-rich) day. */
364 			spin_lock(&c->erase_completion_lock);
365 
366 			waste = jeb->free_size;
367 			jffs2_link_node_ref(c, jeb,
368 					    (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
369 					    waste, NULL);
370 			/* FIXME: that made it count as dirty. Convert to wasted */
371 			jeb->dirty_size -= waste;
372 			c->dirty_size -= waste;
373 			jeb->wasted_size += waste;
374 			c->wasted_size += waste;
375 
376 			jffs2_close_nextblock(c, jeb);
377 			jeb = NULL;
378 		}
379 	}
380 
381 	if (!jeb) {
382 
383 		ret = jffs2_find_nextblock(c);
384 		if (ret)
385 			return ret;
386 
387 		jeb = c->nextblock;
388 
389 		if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
390 			printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
391 			goto restart;
392 		}
393 	}
394 	/* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
395 	   enough space */
396 	*len = jeb->free_size - reserved_size;
397 
398 	if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
399 	    !jeb->first_node->next_in_ino) {
400 		/* Only node in it beforehand was a CLEANMARKER node (we think).
401 		   So mark it obsolete now that there's going to be another node
402 		   in the block. This will reduce used_size to zero but We've
403 		   already set c->nextblock so that jffs2_mark_node_obsolete()
404 		   won't try to refile it to the dirty_list.
405 		*/
406 		spin_unlock(&c->erase_completion_lock);
407 		jffs2_mark_node_obsolete(c, jeb->first_node);
408 		spin_lock(&c->erase_completion_lock);
409 	}
410 
411 	D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
412 		  *len, jeb->offset + (c->sector_size - jeb->free_size)));
413 	return 0;
414 }
415 
416 /**
417  *	jffs2_add_physical_node_ref - add a physical node reference to the list
418  *	@c: superblock info
419  *	@new: new node reference to add
420  *	@len: length of this physical node
421  *
422  *	Should only be used to report nodes for which space has been allocated
423  *	by jffs2_reserve_space.
424  *
425  *	Must be called with the alloc_sem held.
426  */
427 
jffs2_add_physical_node_ref(struct jffs2_sb_info * c,uint32_t ofs,uint32_t len,struct jffs2_inode_cache * ic)428 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
429 						       uint32_t ofs, uint32_t len,
430 						       struct jffs2_inode_cache *ic)
431 {
432 	struct jffs2_eraseblock *jeb;
433 	struct jffs2_raw_node_ref *new;
434 
435 	jeb = &c->blocks[ofs / c->sector_size];
436 
437 	D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
438 		  ofs & ~3, ofs & 3, len));
439 #if 1
440 	/* Allow non-obsolete nodes only to be added at the end of c->nextblock,
441 	   if c->nextblock is set. Note that wbuf.c will file obsolete nodes
442 	   even after refiling c->nextblock */
443 	if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
444 	    && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
445 		printk(KERN_WARNING "argh. node added in wrong place at 0x%08x(%d)\n", ofs & ~3, ofs & 3);
446 		if (c->nextblock)
447 			printk(KERN_WARNING "nextblock 0x%08x", c->nextblock->offset);
448 		else
449 			printk(KERN_WARNING "No nextblock");
450 		printk(", expected at %08x\n", jeb->offset + (c->sector_size - jeb->free_size));
451 		return ERR_PTR(-EINVAL);
452 	}
453 #endif
454 	spin_lock(&c->erase_completion_lock);
455 
456 	new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
457 
458 	if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
459 		/* If it lives on the dirty_list, jffs2_reserve_space will put it there */
460 		D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
461 			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
462 		if (jffs2_wbuf_dirty(c)) {
463 			/* Flush the last write in the block if it's outstanding */
464 			spin_unlock(&c->erase_completion_lock);
465 			jffs2_flush_wbuf_pad(c);
466 			spin_lock(&c->erase_completion_lock);
467 		}
468 
469 		list_add_tail(&jeb->list, &c->clean_list);
470 		c->nextblock = NULL;
471 	}
472 	jffs2_dbg_acct_sanity_check_nolock(c,jeb);
473 	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
474 
475 	spin_unlock(&c->erase_completion_lock);
476 
477 	return new;
478 }
479 
480 
jffs2_complete_reservation(struct jffs2_sb_info * c)481 void jffs2_complete_reservation(struct jffs2_sb_info *c)
482 {
483 	D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
484 	spin_lock(&c->erase_completion_lock);
485 	jffs2_garbage_collect_trigger(c);
486 	spin_unlock(&c->erase_completion_lock);
487 	mutex_unlock(&c->alloc_sem);
488 }
489 
on_list(struct list_head * obj,struct list_head * head)490 static inline int on_list(struct list_head *obj, struct list_head *head)
491 {
492 	struct list_head *this;
493 
494 	list_for_each(this, head) {
495 		if (this == obj) {
496 			D1(printk("%p is on list at %p\n", obj, head));
497 			return 1;
498 
499 		}
500 	}
501 	return 0;
502 }
503 
jffs2_mark_node_obsolete(struct jffs2_sb_info * c,struct jffs2_raw_node_ref * ref)504 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
505 {
506 	struct jffs2_eraseblock *jeb;
507 	int blocknr;
508 	struct jffs2_unknown_node n;
509 	int ret, addedsize;
510 	size_t retlen;
511 	uint32_t freed_len;
512 
513 	if(unlikely(!ref)) {
514 		printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
515 		return;
516 	}
517 	if (ref_obsolete(ref)) {
518 		D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
519 		return;
520 	}
521 	blocknr = ref->flash_offset / c->sector_size;
522 	if (blocknr >= c->nr_blocks) {
523 		printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
524 		BUG();
525 	}
526 	jeb = &c->blocks[blocknr];
527 
528 	if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
529 	    !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
530 		/* Hm. This may confuse static lock analysis. If any of the above
531 		   three conditions is false, we're going to return from this
532 		   function without actually obliterating any nodes or freeing
533 		   any jffs2_raw_node_refs. So we don't need to stop erases from
534 		   happening, or protect against people holding an obsolete
535 		   jffs2_raw_node_ref without the erase_completion_lock. */
536 		mutex_lock(&c->erase_free_sem);
537 	}
538 
539 	spin_lock(&c->erase_completion_lock);
540 
541 	freed_len = ref_totlen(c, jeb, ref);
542 
543 	if (ref_flags(ref) == REF_UNCHECKED) {
544 		D1(if (unlikely(jeb->unchecked_size < freed_len)) {
545 			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",
546 			       freed_len, blocknr, ref->flash_offset, jeb->used_size);
547 			BUG();
548 		})
549 		D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
550 		jeb->unchecked_size -= freed_len;
551 		c->unchecked_size -= freed_len;
552 	} else {
553 		D1(if (unlikely(jeb->used_size < freed_len)) {
554 			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",
555 			       freed_len, blocknr, ref->flash_offset, jeb->used_size);
556 			BUG();
557 		})
558 		D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
559 		jeb->used_size -= freed_len;
560 		c->used_size -= freed_len;
561 	}
562 
563 	// Take care, that wasted size is taken into concern
564 	if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
565 		D1(printk("Dirtying\n"));
566 		addedsize = freed_len;
567 		jeb->dirty_size += freed_len;
568 		c->dirty_size += freed_len;
569 
570 		/* Convert wasted space to dirty, if not a bad block */
571 		if (jeb->wasted_size) {
572 			if (on_list(&jeb->list, &c->bad_used_list)) {
573 				D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
574 					  jeb->offset));
575 				addedsize = 0; /* To fool the refiling code later */
576 			} else {
577 				D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
578 					  jeb->wasted_size, jeb->offset));
579 				addedsize += jeb->wasted_size;
580 				jeb->dirty_size += jeb->wasted_size;
581 				c->dirty_size += jeb->wasted_size;
582 				c->wasted_size -= jeb->wasted_size;
583 				jeb->wasted_size = 0;
584 			}
585 		}
586 	} else {
587 		D1(printk("Wasting\n"));
588 		addedsize = 0;
589 		jeb->wasted_size += freed_len;
590 		c->wasted_size += freed_len;
591 	}
592 	ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
593 
594 	jffs2_dbg_acct_sanity_check_nolock(c, jeb);
595 	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
596 
597 	if (c->flags & JFFS2_SB_FLAG_SCANNING) {
598 		/* Flash scanning is in progress. Don't muck about with the block
599 		   lists because they're not ready yet, and don't actually
600 		   obliterate nodes that look obsolete. If they weren't
601 		   marked obsolete on the flash at the time they _became_
602 		   obsolete, there was probably a reason for that. */
603 		spin_unlock(&c->erase_completion_lock);
604 		/* We didn't lock the erase_free_sem */
605 		return;
606 	}
607 
608 	if (jeb == c->nextblock) {
609 		D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
610 	} else if (!jeb->used_size && !jeb->unchecked_size) {
611 		if (jeb == c->gcblock) {
612 			D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
613 			c->gcblock = NULL;
614 		} else {
615 			D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
616 			list_del(&jeb->list);
617 		}
618 		if (jffs2_wbuf_dirty(c)) {
619 			D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
620 			list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
621 		} else {
622 			if (jiffies & 127) {
623 				/* Most of the time, we just erase it immediately. Otherwise we
624 				   spend ages scanning it on mount, etc. */
625 				D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
626 				list_add_tail(&jeb->list, &c->erase_pending_list);
627 				c->nr_erasing_blocks++;
628 				jffs2_garbage_collect_trigger(c);
629 			} else {
630 				/* Sometimes, however, we leave it elsewhere so it doesn't get
631 				   immediately reused, and we spread the load a bit. */
632 				D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
633 				list_add_tail(&jeb->list, &c->erasable_list);
634 			}
635 		}
636 		D1(printk(KERN_DEBUG "Done OK\n"));
637 	} else if (jeb == c->gcblock) {
638 		D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
639 	} else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
640 		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
641 		list_del(&jeb->list);
642 		D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
643 		list_add_tail(&jeb->list, &c->dirty_list);
644 	} else if (VERYDIRTY(c, jeb->dirty_size) &&
645 		   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
646 		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
647 		list_del(&jeb->list);
648 		D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
649 		list_add_tail(&jeb->list, &c->very_dirty_list);
650 	} else {
651 		D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
652 			  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
653 	}
654 
655 	spin_unlock(&c->erase_completion_lock);
656 
657 	if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
658 		(c->flags & JFFS2_SB_FLAG_BUILDING)) {
659 		/* We didn't lock the erase_free_sem */
660 		return;
661 	}
662 
663 	/* The erase_free_sem is locked, and has been since before we marked the node obsolete
664 	   and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
665 	   the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
666 	   by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
667 
668 	D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
669 	ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
670 	if (ret) {
671 		printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
672 		goto out_erase_sem;
673 	}
674 	if (retlen != sizeof(n)) {
675 		printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
676 		goto out_erase_sem;
677 	}
678 	if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
679 		printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
680 		goto out_erase_sem;
681 	}
682 	if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
683 		D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
684 		goto out_erase_sem;
685 	}
686 	/* XXX FIXME: This is ugly now */
687 	n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
688 	ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
689 	if (ret) {
690 		printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
691 		goto out_erase_sem;
692 	}
693 	if (retlen != sizeof(n)) {
694 		printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
695 		goto out_erase_sem;
696 	}
697 
698 	/* Nodes which have been marked obsolete no longer need to be
699 	   associated with any inode. Remove them from the per-inode list.
700 
701 	   Note we can't do this for NAND at the moment because we need
702 	   obsolete dirent nodes to stay on the lists, because of the
703 	   horridness in jffs2_garbage_collect_deletion_dirent(). Also
704 	   because we delete the inocache, and on NAND we need that to
705 	   stay around until all the nodes are actually erased, in order
706 	   to stop us from giving the same inode number to another newly
707 	   created inode. */
708 	if (ref->next_in_ino) {
709 		struct jffs2_inode_cache *ic;
710 		struct jffs2_raw_node_ref **p;
711 
712 		spin_lock(&c->erase_completion_lock);
713 
714 		ic = jffs2_raw_ref_to_ic(ref);
715 		for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
716 			;
717 
718 		*p = ref->next_in_ino;
719 		ref->next_in_ino = NULL;
720 
721 		switch (ic->class) {
722 #ifdef CONFIG_JFFS2_FS_XATTR
723 			case RAWNODE_CLASS_XATTR_DATUM:
724 				jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
725 				break;
726 			case RAWNODE_CLASS_XATTR_REF:
727 				jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
728 				break;
729 #endif
730 			default:
731 				if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
732 					jffs2_del_ino_cache(c, ic);
733 				break;
734 		}
735 		spin_unlock(&c->erase_completion_lock);
736 	}
737 
738  out_erase_sem:
739 	mutex_unlock(&c->erase_free_sem);
740 }
741 
jffs2_thread_should_wake(struct jffs2_sb_info * c)742 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
743 {
744 	int ret = 0;
745 	uint32_t dirty;
746 	int nr_very_dirty = 0;
747 	struct jffs2_eraseblock *jeb;
748 
749 	if (!list_empty(&c->erase_complete_list) ||
750 	    !list_empty(&c->erase_pending_list))
751 		return 1;
752 
753 	if (c->unchecked_size) {
754 		D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
755 			  c->unchecked_size, c->checked_ino));
756 		return 1;
757 	}
758 
759 	/* dirty_size contains blocks on erase_pending_list
760 	 * those blocks are counted in c->nr_erasing_blocks.
761 	 * If one block is actually erased, it is not longer counted as dirty_space
762 	 * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
763 	 * with c->nr_erasing_blocks * c->sector_size again.
764 	 * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
765 	 * This helps us to force gc and pick eventually a clean block to spread the load.
766 	 */
767 	dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
768 
769 	if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
770 			(dirty > c->nospc_dirty_size))
771 		ret = 1;
772 
773 	list_for_each_entry(jeb, &c->very_dirty_list, list) {
774 		nr_very_dirty++;
775 		if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
776 			ret = 1;
777 			/* In debug mode, actually go through and count them all */
778 			D1(continue);
779 			break;
780 		}
781 	}
782 
783 	D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
784 		  c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, nr_very_dirty, ret?"yes":"no"));
785 
786 	return ret;
787 }
788