xref: /openbmc/linux/fs/jffs2/nodemgmt.c (revision 174cd4b1)
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  */
jffs2_rp_can_write(struct jffs2_sb_info * c)24 static 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 
71 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
72 				  uint32_t *len, uint32_t sumsize);
73 
jffs2_reserve_space(struct jffs2_sb_info * c,uint32_t minsize,uint32_t * len,int prio,uint32_t sumsize)74 int 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 
203 out:
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 
jffs2_reserve_space_gc(struct jffs2_sb_info * c,uint32_t minsize,uint32_t * len,uint32_t sumsize)212 int 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 
jffs2_close_nextblock(struct jffs2_sb_info * c,struct jffs2_eraseblock * jeb)243 static 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 
jffs2_find_nextblock(struct jffs2_sb_info * c)280 static 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 */
jffs2_do_reserve_space(struct jffs2_sb_info * c,uint32_t minsize,uint32_t * len,uint32_t sumsize)354 static 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 
jffs2_add_physical_node_ref(struct jffs2_sb_info * c,uint32_t ofs,uint32_t len,struct jffs2_inode_cache * ic)500 struct 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 
jffs2_complete_reservation(struct jffs2_sb_info * c)556 void 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 
on_list(struct list_head * obj,struct list_head * head)565 static 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 
jffs2_mark_node_obsolete(struct jffs2_sb_info * c,struct jffs2_raw_node_ref * ref)579 void 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 
jffs2_thread_should_wake(struct jffs2_sb_info * c)837 int 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 }
884