[PATCH] fs: use list_move()
[linux-2.6.git] / fs / jffs2 / nodemgmt.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001-2003 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  * $Id: nodemgmt.c,v 1.127 2005/09/20 15:49:12 dedekind Exp $
11  *
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/compiler.h>
18 #include <linux/sched.h> /* For cond_resched() */
19 #include "nodelist.h"
20 #include "debug.h"
21
22 /**
23  *      jffs2_reserve_space - request physical space to write nodes to flash
24  *      @c: superblock info
25  *      @minsize: Minimum acceptable size of allocation
26  *      @len: Returned value of allocation length
27  *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
28  *
29  *      Requests a block of physical space on the flash. Returns zero for success
30  *      and puts 'len' into the appropriate place, or returns -ENOSPC or other 
31  *      error if appropriate. Doesn't return len since that's 
32  *
33  *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
34  *      allocation semaphore, to prevent more than one allocation from being
35  *      active at any time. The semaphore is later released by jffs2_commit_allocation()
36  *
37  *      jffs2_reserve_space() may trigger garbage collection in order to make room
38  *      for the requested allocation.
39  */
40
41 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
42                                   uint32_t *len, uint32_t sumsize);
43
44 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
45                         uint32_t *len, int prio, uint32_t sumsize)
46 {
47         int ret = -EAGAIN;
48         int blocksneeded = c->resv_blocks_write;
49         /* align it */
50         minsize = PAD(minsize);
51
52         D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
53         down(&c->alloc_sem);
54
55         D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
56
57         spin_lock(&c->erase_completion_lock);
58
59         /* this needs a little more thought (true <tglx> :)) */
60         while(ret == -EAGAIN) {
61                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
62                         int ret;
63                         uint32_t dirty, avail;
64
65                         /* calculate real dirty size
66                          * dirty_size contains blocks on erase_pending_list
67                          * those blocks are counted in c->nr_erasing_blocks.
68                          * If one block is actually erased, it is not longer counted as dirty_space
69                          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
70                          * with c->nr_erasing_blocks * c->sector_size again.
71                          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
72                          * This helps us to force gc and pick eventually a clean block to spread the load.
73                          * We add unchecked_size here, as we hopefully will find some space to use.
74                          * This will affect the sum only once, as gc first finishes checking
75                          * of nodes.
76                          */
77                         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
78                         if (dirty < c->nospc_dirty_size) {
79                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
80                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
81                                         break;
82                                 }
83                                 D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
84                                           dirty, c->unchecked_size, c->sector_size));
85
86                                 spin_unlock(&c->erase_completion_lock);
87                                 up(&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                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
104                                         break;
105                                 }
106
107                                 D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
108                                           avail, blocksneeded * c->sector_size));
109                                 spin_unlock(&c->erase_completion_lock);
110                                 up(&c->alloc_sem);
111                                 return -ENOSPC;
112                         }
113
114                         up(&c->alloc_sem);
115
116                         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",
117                                   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,
118                                   c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
119                         spin_unlock(&c->erase_completion_lock);
120
121                         ret = jffs2_garbage_collect_pass(c);
122                         if (ret)
123                                 return ret;
124
125                         cond_resched();
126
127                         if (signal_pending(current))
128                                 return -EINTR;
129
130                         down(&c->alloc_sem);
131                         spin_lock(&c->erase_completion_lock);
132                 }
133
134                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
135                 if (ret) {
136                         D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
137                 }
138         }
139         spin_unlock(&c->erase_completion_lock);
140         if (!ret)
141                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
142         if (ret)
143                 up(&c->alloc_sem);
144         return ret;
145 }
146
147 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
148                            uint32_t *len, uint32_t sumsize)
149 {
150         int ret = -EAGAIN;
151         minsize = PAD(minsize);
152
153         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
154
155         spin_lock(&c->erase_completion_lock);
156         while(ret == -EAGAIN) {
157                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
158                 if (ret) {
159                         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
160                 }
161         }
162         spin_unlock(&c->erase_completion_lock);
163         if (!ret)
164                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
165
166         return ret;
167 }
168
169
170 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
171
172 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
173 {
174
175         /* Check, if we have a dirty block now, or if it was dirty already */
176         if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
177                 c->dirty_size += jeb->wasted_size;
178                 c->wasted_size -= jeb->wasted_size;
179                 jeb->dirty_size += jeb->wasted_size;
180                 jeb->wasted_size = 0;
181                 if (VERYDIRTY(c, jeb->dirty_size)) {
182                         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",
183                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
184                         list_add_tail(&jeb->list, &c->very_dirty_list);
185                 } else {
186                         D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
187                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
188                         list_add_tail(&jeb->list, &c->dirty_list);
189                 }
190         } else {
191                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
192                   jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
193                 list_add_tail(&jeb->list, &c->clean_list);
194         }
195         c->nextblock = NULL;
196
197 }
198
199 /* Select a new jeb for nextblock */
200
201 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
202 {
203         struct list_head *next;
204
205         /* Take the next block off the 'free' list */
206
207         if (list_empty(&c->free_list)) {
208
209                 if (!c->nr_erasing_blocks &&
210                         !list_empty(&c->erasable_list)) {
211                         struct jffs2_eraseblock *ejeb;
212
213                         ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
214                         list_move_tail(&ejeb->list, &c->erase_pending_list);
215                         c->nr_erasing_blocks++;
216                         jffs2_erase_pending_trigger(c);
217                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
218                                   ejeb->offset));
219                 }
220
221                 if (!c->nr_erasing_blocks &&
222                         !list_empty(&c->erasable_pending_wbuf_list)) {
223                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
224                         /* c->nextblock is NULL, no update to c->nextblock allowed */
225                         spin_unlock(&c->erase_completion_lock);
226                         jffs2_flush_wbuf_pad(c);
227                         spin_lock(&c->erase_completion_lock);
228                         /* Have another go. It'll be on the erasable_list now */
229                         return -EAGAIN;
230                 }
231
232                 if (!c->nr_erasing_blocks) {
233                         /* Ouch. We're in GC, or we wouldn't have got here.
234                            And there's no space left. At all. */
235                         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",
236                                    c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
237                                    list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
238                         return -ENOSPC;
239                 }
240
241                 spin_unlock(&c->erase_completion_lock);
242                 /* Don't wait for it; just erase one right now */
243                 jffs2_erase_pending_blocks(c, 1);
244                 spin_lock(&c->erase_completion_lock);
245
246                 /* An erase may have failed, decreasing the
247                    amount of free space available. So we must
248                    restart from the beginning */
249                 return -EAGAIN;
250         }
251
252         next = c->free_list.next;
253         list_del(next);
254         c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
255         c->nr_free_blocks--;
256
257         jffs2_sum_reset_collected(c->summary); /* reset collected summary */
258
259         D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
260
261         return 0;
262 }
263
264 /* Called with alloc sem _and_ erase_completion_lock */
265 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
266                                   uint32_t *len, uint32_t sumsize)
267 {
268         struct jffs2_eraseblock *jeb = c->nextblock;
269         uint32_t reserved_size;                         /* for summary information at the end of the jeb */
270         int ret;
271
272  restart:
273         reserved_size = 0;
274
275         if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
276                                                         /* NOSUM_SIZE means not to generate summary */
277
278                 if (jeb) {
279                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
280                         dbg_summary("minsize=%d , jeb->free=%d ,"
281                                                 "summary->size=%d , sumsize=%d\n",
282                                                 minsize, jeb->free_size,
283                                                 c->summary->sum_size, sumsize);
284                 }
285
286                 /* Is there enough space for writing out the current node, or we have to
287                    write out summary information now, close this jeb and select new nextblock? */
288                 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
289                                         JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
290
291                         /* Has summary been disabled for this jeb? */
292                         if (jffs2_sum_is_disabled(c->summary)) {
293                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
294                                 goto restart;
295                         }
296
297                         /* Writing out the collected summary information */
298                         dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
299                         ret = jffs2_sum_write_sumnode(c);
300
301                         if (ret)
302                                 return ret;
303
304                         if (jffs2_sum_is_disabled(c->summary)) {
305                                 /* jffs2_write_sumnode() couldn't write out the summary information
306                                    diabling summary for this jeb and free the collected information
307                                  */
308                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
309                                 goto restart;
310                         }
311
312                         jffs2_close_nextblock(c, jeb);
313                         jeb = NULL;
314                         /* keep always valid value in reserved_size */
315                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
316                 }
317         } else {
318                 if (jeb && minsize > jeb->free_size) {
319                         uint32_t waste;
320
321                         /* Skip the end of this block and file it as having some dirty space */
322                         /* If there's a pending write to it, flush now */
323
324                         if (jffs2_wbuf_dirty(c)) {
325                                 spin_unlock(&c->erase_completion_lock);
326                                 D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
327                                 jffs2_flush_wbuf_pad(c);
328                                 spin_lock(&c->erase_completion_lock);
329                                 jeb = c->nextblock;
330                                 goto restart;
331                         }
332
333                         spin_unlock(&c->erase_completion_lock);
334
335                         ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
336                         if (ret)
337                                 return ret;
338                         /* Just lock it again and continue. Nothing much can change because
339                            we hold c->alloc_sem anyway. In fact, it's not entirely clear why
340                            we hold c->erase_completion_lock in the majority of this function...
341                            but that's a question for another (more caffeine-rich) day. */
342                         spin_lock(&c->erase_completion_lock);
343
344                         waste = jeb->free_size;
345                         jffs2_link_node_ref(c, jeb,
346                                             (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
347                                             waste, NULL);
348                         /* FIXME: that made it count as dirty. Convert to wasted */
349                         jeb->dirty_size -= waste;
350                         c->dirty_size -= waste;
351                         jeb->wasted_size += waste;
352                         c->wasted_size += waste;
353
354                         jffs2_close_nextblock(c, jeb);
355                         jeb = NULL;
356                 }
357         }
358
359         if (!jeb) {
360
361                 ret = jffs2_find_nextblock(c);
362                 if (ret)
363                         return ret;
364
365                 jeb = c->nextblock;
366
367                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
368                         printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
369                         goto restart;
370                 }
371         }
372         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
373            enough space */
374         *len = jeb->free_size - reserved_size;
375
376         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
377             !jeb->first_node->next_in_ino) {
378                 /* Only node in it beforehand was a CLEANMARKER node (we think).
379                    So mark it obsolete now that there's going to be another node
380                    in the block. This will reduce used_size to zero but We've
381                    already set c->nextblock so that jffs2_mark_node_obsolete()
382                    won't try to refile it to the dirty_list.
383                 */
384                 spin_unlock(&c->erase_completion_lock);
385                 jffs2_mark_node_obsolete(c, jeb->first_node);
386                 spin_lock(&c->erase_completion_lock);
387         }
388
389         D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
390                   *len, jeb->offset + (c->sector_size - jeb->free_size)));
391         return 0;
392 }
393
394 /**
395  *      jffs2_add_physical_node_ref - add a physical node reference to the list
396  *      @c: superblock info
397  *      @new: new node reference to add
398  *      @len: length of this physical node
399  *
400  *      Should only be used to report nodes for which space has been allocated
401  *      by jffs2_reserve_space.
402  *
403  *      Must be called with the alloc_sem held.
404  */
405
406 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
407                                                        uint32_t ofs, uint32_t len,
408                                                        struct jffs2_inode_cache *ic)
409 {
410         struct jffs2_eraseblock *jeb;
411         struct jffs2_raw_node_ref *new;
412
413         jeb = &c->blocks[ofs / c->sector_size];
414
415         D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
416                   ofs & ~3, ofs & 3, len));
417 #if 1
418         /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 
419            if c->nextblock is set. Note that wbuf.c will file obsolete nodes
420            even after refiling c->nextblock */
421         if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
422             && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
423                 printk(KERN_WARNING "argh. node added in wrong place\n");
424                 return ERR_PTR(-EINVAL);
425         }
426 #endif
427         spin_lock(&c->erase_completion_lock);
428
429         new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
430
431         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
432                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
433                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
434                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
435                 if (jffs2_wbuf_dirty(c)) {
436                         /* Flush the last write in the block if it's outstanding */
437                         spin_unlock(&c->erase_completion_lock);
438                         jffs2_flush_wbuf_pad(c);
439                         spin_lock(&c->erase_completion_lock);
440                 }
441
442                 list_add_tail(&jeb->list, &c->clean_list);
443                 c->nextblock = NULL;
444         }
445         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
446         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
447
448         spin_unlock(&c->erase_completion_lock);
449
450         return new;
451 }
452
453
454 void jffs2_complete_reservation(struct jffs2_sb_info *c)
455 {
456         D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
457         jffs2_garbage_collect_trigger(c);
458         up(&c->alloc_sem);
459 }
460
461 static inline int on_list(struct list_head *obj, struct list_head *head)
462 {
463         struct list_head *this;
464
465         list_for_each(this, head) {
466                 if (this == obj) {
467                         D1(printk("%p is on list at %p\n", obj, head));
468                         return 1;
469
470                 }
471         }
472         return 0;
473 }
474
475 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
476 {
477         struct jffs2_eraseblock *jeb;
478         int blocknr;
479         struct jffs2_unknown_node n;
480         int ret, addedsize;
481         size_t retlen;
482         uint32_t freed_len;
483
484         if(unlikely(!ref)) {
485                 printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
486                 return;
487         }
488         if (ref_obsolete(ref)) {
489                 D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
490                 return;
491         }
492         blocknr = ref->flash_offset / c->sector_size;
493         if (blocknr >= c->nr_blocks) {
494                 printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
495                 BUG();
496         }
497         jeb = &c->blocks[blocknr];
498
499         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
500             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
501                 /* Hm. This may confuse static lock analysis. If any of the above
502                    three conditions is false, we're going to return from this
503                    function without actually obliterating any nodes or freeing
504                    any jffs2_raw_node_refs. So we don't need to stop erases from
505                    happening, or protect against people holding an obsolete
506                    jffs2_raw_node_ref without the erase_completion_lock. */
507                 down(&c->erase_free_sem);
508         }
509
510         spin_lock(&c->erase_completion_lock);
511
512         freed_len = ref_totlen(c, jeb, ref);
513
514         if (ref_flags(ref) == REF_UNCHECKED) {
515                 D1(if (unlikely(jeb->unchecked_size < freed_len)) {
516                         printk(KERN_NOTICE "raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n",
517                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
518                         BUG();
519                 })
520                 D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
521                 jeb->unchecked_size -= freed_len;
522                 c->unchecked_size -= freed_len;
523         } else {
524                 D1(if (unlikely(jeb->used_size < freed_len)) {
525                         printk(KERN_NOTICE "raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
526                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
527                         BUG();
528                 })
529                 D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
530                 jeb->used_size -= freed_len;
531                 c->used_size -= freed_len;
532         }
533
534         // Take care, that wasted size is taken into concern
535         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
536                 D1(printk("Dirtying\n"));
537                 addedsize = freed_len;
538                 jeb->dirty_size += freed_len;
539                 c->dirty_size += freed_len;
540
541                 /* Convert wasted space to dirty, if not a bad block */
542                 if (jeb->wasted_size) {
543                         if (on_list(&jeb->list, &c->bad_used_list)) {
544                                 D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
545                                           jeb->offset));
546                                 addedsize = 0; /* To fool the refiling code later */
547                         } else {
548                                 D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
549                                           jeb->wasted_size, jeb->offset));
550                                 addedsize += jeb->wasted_size;
551                                 jeb->dirty_size += jeb->wasted_size;
552                                 c->dirty_size += jeb->wasted_size;
553                                 c->wasted_size -= jeb->wasted_size;
554                                 jeb->wasted_size = 0;
555                         }
556                 }
557         } else {
558                 D1(printk("Wasting\n"));
559                 addedsize = 0;
560                 jeb->wasted_size += freed_len;
561                 c->wasted_size += freed_len;
562         }
563         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
564
565         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
566         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
567
568         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
569                 /* Flash scanning is in progress. Don't muck about with the block
570                    lists because they're not ready yet, and don't actually
571                    obliterate nodes that look obsolete. If they weren't
572                    marked obsolete on the flash at the time they _became_
573                    obsolete, there was probably a reason for that. */
574                 spin_unlock(&c->erase_completion_lock);
575                 /* We didn't lock the erase_free_sem */
576                 return;
577         }
578
579         if (jeb == c->nextblock) {
580                 D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
581         } else if (!jeb->used_size && !jeb->unchecked_size) {
582                 if (jeb == c->gcblock) {
583                         D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
584                         c->gcblock = NULL;
585                 } else {
586                         D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
587                         list_del(&jeb->list);
588                 }
589                 if (jffs2_wbuf_dirty(c)) {
590                         D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
591                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
592                 } else {
593                         if (jiffies & 127) {
594                                 /* Most of the time, we just erase it immediately. Otherwise we
595                                    spend ages scanning it on mount, etc. */
596                                 D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
597                                 list_add_tail(&jeb->list, &c->erase_pending_list);
598                                 c->nr_erasing_blocks++;
599                                 jffs2_erase_pending_trigger(c);
600                         } else {
601                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
602                                    immediately reused, and we spread the load a bit. */
603                                 D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
604                                 list_add_tail(&jeb->list, &c->erasable_list);
605                         }
606                 }
607                 D1(printk(KERN_DEBUG "Done OK\n"));
608         } else if (jeb == c->gcblock) {
609                 D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
610         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
611                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
612                 list_del(&jeb->list);
613                 D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
614                 list_add_tail(&jeb->list, &c->dirty_list);
615         } else if (VERYDIRTY(c, jeb->dirty_size) &&
616                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
617                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
618                 list_del(&jeb->list);
619                 D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
620                 list_add_tail(&jeb->list, &c->very_dirty_list);
621         } else {
622                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
623                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
624         }
625
626         spin_unlock(&c->erase_completion_lock);
627
628         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
629                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
630                 /* We didn't lock the erase_free_sem */
631                 return;
632         }
633
634         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
635            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
636            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
637            by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
638
639         D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
640         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
641         if (ret) {
642                 printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
643                 goto out_erase_sem;
644         }
645         if (retlen != sizeof(n)) {
646                 printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
647                 goto out_erase_sem;
648         }
649         if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
650                 printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
651                 goto out_erase_sem;
652         }
653         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
654                 D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
655                 goto out_erase_sem;
656         }
657         /* XXX FIXME: This is ugly now */
658         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
659         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
660         if (ret) {
661                 printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
662                 goto out_erase_sem;
663         }
664         if (retlen != sizeof(n)) {
665                 printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
666                 goto out_erase_sem;
667         }
668
669         /* Nodes which have been marked obsolete no longer need to be
670            associated with any inode. Remove them from the per-inode list.
671
672            Note we can't do this for NAND at the moment because we need
673            obsolete dirent nodes to stay on the lists, because of the
674            horridness in jffs2_garbage_collect_deletion_dirent(). Also
675            because we delete the inocache, and on NAND we need that to
676            stay around until all the nodes are actually erased, in order
677            to stop us from giving the same inode number to another newly
678            created inode. */
679         if (ref->next_in_ino) {
680                 struct jffs2_inode_cache *ic;
681                 struct jffs2_raw_node_ref **p;
682
683                 spin_lock(&c->erase_completion_lock);
684
685                 ic = jffs2_raw_ref_to_ic(ref);
686                 /* It seems we should never call jffs2_mark_node_obsolete() for
687                    XATTR nodes.... yet. Make sure we notice if/when we change
688                    that :) */
689                 BUG_ON(ic->class != RAWNODE_CLASS_INODE_CACHE);
690                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
691                         ;
692
693                 *p = ref->next_in_ino;
694                 ref->next_in_ino = NULL;
695
696                 if (ic->nodes == (void *)ic && ic->nlink == 0)
697                         jffs2_del_ino_cache(c, ic);
698
699                 spin_unlock(&c->erase_completion_lock);
700         }
701
702  out_erase_sem:
703         up(&c->erase_free_sem);
704 }
705
706 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
707 {
708         int ret = 0;
709         uint32_t dirty;
710
711         if (c->unchecked_size) {
712                 D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
713                           c->unchecked_size, c->checked_ino));
714                 return 1;
715         }
716
717         /* dirty_size contains blocks on erase_pending_list
718          * those blocks are counted in c->nr_erasing_blocks.
719          * If one block is actually erased, it is not longer counted as dirty_space
720          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
721          * with c->nr_erasing_blocks * c->sector_size again.
722          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
723          * This helps us to force gc and pick eventually a clean block to spread the load.
724          */
725         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
726
727         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
728                         (dirty > c->nospc_dirty_size))
729                 ret = 1;
730
731         D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x: %s\n",
732                   c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, ret?"yes":"no"));
733
734         return ret;
735 }