Root/fs/jffs2/nodemgmt.c

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/slab.h>
14#include <linux/mtd/mtd.h>
15#include <linux/compiler.h>
16#include <linux/sched.h> /* For cond_resched() */
17#include "nodelist.h"
18#include "debug.h"
19
20/**
21 * jffs2_reserve_space - request physical space to write nodes to flash
22 * @c: superblock info
23 * @minsize: Minimum acceptable size of allocation
24 * @len: Returned value of allocation length
25 * @prio: Allocation type - ALLOC_{NORMAL,DELETION}
26 *
27 * Requests a block of physical space on the flash. Returns zero for success
28 * and puts 'len' into the appropriate place, or returns -ENOSPC or other
29 * error if appropriate. Doesn't return len since that's
30 *
31 * If it returns zero, jffs2_reserve_space() also downs the per-filesystem
32 * allocation semaphore, to prevent more than one allocation from being
33 * active at any time. The semaphore is later released by jffs2_commit_allocation()
34 *
35 * jffs2_reserve_space() may trigger garbage collection in order to make room
36 * for the requested allocation.
37 */
38
39static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
40                  uint32_t *len, uint32_t sumsize);
41
42int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
43            uint32_t *len, int prio, uint32_t sumsize)
44{
45    int ret = -EAGAIN;
46    int blocksneeded = c->resv_blocks_write;
47    /* align it */
48    minsize = PAD(minsize);
49
50    D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
51    mutex_lock(&c->alloc_sem);
52
53    D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
54
55    spin_lock(&c->erase_completion_lock);
56
57    /* this needs a little more thought (true <tglx> :)) */
58    while(ret == -EAGAIN) {
59        while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
60            uint32_t dirty, avail;
61
62            /* calculate real dirty size
63             * dirty_size contains blocks on erase_pending_list
64             * those blocks are counted in c->nr_erasing_blocks.
65             * If one block is actually erased, it is not longer counted as dirty_space
66             * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
67             * with c->nr_erasing_blocks * c->sector_size again.
68             * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
69             * This helps us to force gc and pick eventually a clean block to spread the load.
70             * We add unchecked_size here, as we hopefully will find some space to use.
71             * This will affect the sum only once, as gc first finishes checking
72             * of nodes.
73             */
74            dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
75            if (dirty < c->nospc_dirty_size) {
76                if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
77                    D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
78                    break;
79                }
80                D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
81                      dirty, c->unchecked_size, c->sector_size));
82
83                spin_unlock(&c->erase_completion_lock);
84                mutex_unlock(&c->alloc_sem);
85                return -ENOSPC;
86            }
87
88            /* Calc possibly available space. Possibly available means that we
89             * don't know, if unchecked size contains obsoleted nodes, which could give us some
90             * more usable space. This will affect the sum only once, as gc first finishes checking
91             * of nodes.
92             + Return -ENOSPC, if the maximum possibly available space is less or equal than
93             * blocksneeded * sector_size.
94             * This blocks endless gc looping on a filesystem, which is nearly full, even if
95             * the check above passes.
96             */
97            avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
98            if ( (avail / c->sector_size) <= blocksneeded) {
99                if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
100                    D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
101                    break;
102                }
103
104                D1(printk(KERN_DEBUG "max. available size 0x%08x < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
105                      avail, blocksneeded * c->sector_size));
106                spin_unlock(&c->erase_completion_lock);
107                mutex_unlock(&c->alloc_sem);
108                return -ENOSPC;
109            }
110
111            mutex_unlock(&c->alloc_sem);
112
113            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",
114                  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,
115                  c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
116            spin_unlock(&c->erase_completion_lock);
117
118            ret = jffs2_garbage_collect_pass(c);
119
120            if (ret == -EAGAIN)
121                jffs2_erase_pending_blocks(c, 1);
122            else if (ret)
123                return ret;
124
125            cond_resched();
126
127            if (signal_pending(current))
128                return -EINTR;
129
130            mutex_lock(&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        mutex_unlock(&c->alloc_sem);
144    return ret;
145}
146
147int 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
172static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
173{
174
175    if (c->nextblock == NULL) {
176        D1(printk(KERN_DEBUG "jffs2_close_nextblock: Erase block at 0x%08x has already been placed in a list\n",
177          jeb->offset));
178        return;
179    }
180    /* Check, if we have a dirty block now, or if it was dirty already */
181    if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
182        c->dirty_size += jeb->wasted_size;
183        c->wasted_size -= jeb->wasted_size;
184        jeb->dirty_size += jeb->wasted_size;
185        jeb->wasted_size = 0;
186        if (VERYDIRTY(c, jeb->dirty_size)) {
187            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",
188              jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
189            list_add_tail(&jeb->list, &c->very_dirty_list);
190        } else {
191            D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_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->dirty_list);
194        }
195    } else {
196        D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
197          jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
198        list_add_tail(&jeb->list, &c->clean_list);
199    }
200    c->nextblock = NULL;
201
202}
203
204/* Select a new jeb for nextblock */
205
206static int jffs2_find_nextblock(struct jffs2_sb_info *c)
207{
208    struct list_head *next;
209
210    /* Take the next block off the 'free' list */
211
212    if (list_empty(&c->free_list)) {
213
214        if (!c->nr_erasing_blocks &&
215            !list_empty(&c->erasable_list)) {
216            struct jffs2_eraseblock *ejeb;
217
218            ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
219            list_move_tail(&ejeb->list, &c->erase_pending_list);
220            c->nr_erasing_blocks++;
221            jffs2_erase_pending_trigger(c);
222            D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
223                  ejeb->offset));
224        }
225
226        if (!c->nr_erasing_blocks &&
227            !list_empty(&c->erasable_pending_wbuf_list)) {
228            D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
229            /* c->nextblock is NULL, no update to c->nextblock allowed */
230            spin_unlock(&c->erase_completion_lock);
231            jffs2_flush_wbuf_pad(c);
232            spin_lock(&c->erase_completion_lock);
233            /* Have another go. It'll be on the erasable_list now */
234            return -EAGAIN;
235        }
236
237        if (!c->nr_erasing_blocks) {
238            /* Ouch. We're in GC, or we wouldn't have got here.
239               And there's no space left. At all. */
240            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",
241                   c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
242                   list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
243            return -ENOSPC;
244        }
245
246        spin_unlock(&c->erase_completion_lock);
247        /* Don't wait for it; just erase one right now */
248        jffs2_erase_pending_blocks(c, 1);
249        spin_lock(&c->erase_completion_lock);
250
251        /* An erase may have failed, decreasing the
252           amount of free space available. So we must
253           restart from the beginning */
254        return -EAGAIN;
255    }
256
257    next = c->free_list.next;
258    list_del(next);
259    c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
260    c->nr_free_blocks--;
261
262    jffs2_sum_reset_collected(c->summary); /* reset collected summary */
263
264#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
265    /* adjust write buffer offset, else we get a non contiguous write bug */
266    if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
267        c->wbuf_ofs = 0xffffffff;
268#endif
269
270    D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
271
272    return 0;
273}
274
275/* Called with alloc sem _and_ erase_completion_lock */
276static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
277                  uint32_t *len, uint32_t sumsize)
278{
279    struct jffs2_eraseblock *jeb = c->nextblock;
280    uint32_t reserved_size; /* for summary information at the end of the jeb */
281    int ret;
282
283 restart:
284    reserved_size = 0;
285
286    if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
287                            /* NOSUM_SIZE means not to generate summary */
288
289        if (jeb) {
290            reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
291            dbg_summary("minsize=%d , jeb->free=%d ,"
292                        "summary->size=%d , sumsize=%d\n",
293                        minsize, jeb->free_size,
294                        c->summary->sum_size, sumsize);
295        }
296
297        /* Is there enough space for writing out the current node, or we have to
298           write out summary information now, close this jeb and select new nextblock? */
299        if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
300                    JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
301
302            /* Has summary been disabled for this jeb? */
303            if (jffs2_sum_is_disabled(c->summary)) {
304                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
305                goto restart;
306            }
307
308            /* Writing out the collected summary information */
309            dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
310            ret = jffs2_sum_write_sumnode(c);
311
312            if (ret)
313                return ret;
314
315            if (jffs2_sum_is_disabled(c->summary)) {
316                /* jffs2_write_sumnode() couldn't write out the summary information
317                   diabling summary for this jeb and free the collected information
318                 */
319                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
320                goto restart;
321            }
322
323            jffs2_close_nextblock(c, jeb);
324            jeb = NULL;
325            /* keep always valid value in reserved_size */
326            reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
327        }
328    } else {
329        if (jeb && minsize > jeb->free_size) {
330            uint32_t waste;
331
332            /* Skip the end of this block and file it as having some dirty space */
333            /* If there's a pending write to it, flush now */
334
335            if (jffs2_wbuf_dirty(c)) {
336                spin_unlock(&c->erase_completion_lock);
337                D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
338                jffs2_flush_wbuf_pad(c);
339                spin_lock(&c->erase_completion_lock);
340                jeb = c->nextblock;
341                goto restart;
342            }
343
344            spin_unlock(&c->erase_completion_lock);
345
346            ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
347            if (ret)
348                return ret;
349            /* Just lock it again and continue. Nothing much can change because
350               we hold c->alloc_sem anyway. In fact, it's not entirely clear why
351               we hold c->erase_completion_lock in the majority of this function...
352               but that's a question for another (more caffeine-rich) day. */
353            spin_lock(&c->erase_completion_lock);
354
355            waste = jeb->free_size;
356            jffs2_link_node_ref(c, jeb,
357                        (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
358                        waste, NULL);
359            /* FIXME: that made it count as dirty. Convert to wasted */
360            jeb->dirty_size -= waste;
361            c->dirty_size -= waste;
362            jeb->wasted_size += waste;
363            c->wasted_size += waste;
364
365            jffs2_close_nextblock(c, jeb);
366            jeb = NULL;
367        }
368    }
369
370    if (!jeb) {
371
372        ret = jffs2_find_nextblock(c);
373        if (ret)
374            return ret;
375
376        jeb = c->nextblock;
377
378        if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
379            printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
380            goto restart;
381        }
382    }
383    /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
384       enough space */
385    *len = jeb->free_size - reserved_size;
386
387    if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
388        !jeb->first_node->next_in_ino) {
389        /* Only node in it beforehand was a CLEANMARKER node (we think).
390           So mark it obsolete now that there's going to be another node
391           in the block. This will reduce used_size to zero but We've
392           already set c->nextblock so that jffs2_mark_node_obsolete()
393           won't try to refile it to the dirty_list.
394        */
395        spin_unlock(&c->erase_completion_lock);
396        jffs2_mark_node_obsolete(c, jeb->first_node);
397        spin_lock(&c->erase_completion_lock);
398    }
399
400    D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
401          *len, jeb->offset + (c->sector_size - jeb->free_size)));
402    return 0;
403}
404
405/**
406 * jffs2_add_physical_node_ref - add a physical node reference to the list
407 * @c: superblock info
408 * @new: new node reference to add
409 * @len: length of this physical node
410 *
411 * Should only be used to report nodes for which space has been allocated
412 * by jffs2_reserve_space.
413 *
414 * Must be called with the alloc_sem held.
415 */
416
417struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
418                               uint32_t ofs, uint32_t len,
419                               struct jffs2_inode_cache *ic)
420{
421    struct jffs2_eraseblock *jeb;
422    struct jffs2_raw_node_ref *new;
423
424    jeb = &c->blocks[ofs / c->sector_size];
425
426    D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
427          ofs & ~3, ofs & 3, len));
428#if 1
429    /* Allow non-obsolete nodes only to be added at the end of c->nextblock,
430       if c->nextblock is set. Note that wbuf.c will file obsolete nodes
431       even after refiling c->nextblock */
432    if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
433        && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
434        printk(KERN_WARNING "argh. node added in wrong place at 0x%08x(%d)\n", ofs & ~3, ofs & 3);
435        if (c->nextblock)
436            printk(KERN_WARNING "nextblock 0x%08x", c->nextblock->offset);
437        else
438            printk(KERN_WARNING "No nextblock");
439        printk(", expected at %08x\n", jeb->offset + (c->sector_size - jeb->free_size));
440        return ERR_PTR(-EINVAL);
441    }
442#endif
443    spin_lock(&c->erase_completion_lock);
444
445    new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
446
447    if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
448        /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
449        D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
450              jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
451        if (jffs2_wbuf_dirty(c)) {
452            /* Flush the last write in the block if it's outstanding */
453            spin_unlock(&c->erase_completion_lock);
454            jffs2_flush_wbuf_pad(c);
455            spin_lock(&c->erase_completion_lock);
456        }
457
458        list_add_tail(&jeb->list, &c->clean_list);
459        c->nextblock = NULL;
460    }
461    jffs2_dbg_acct_sanity_check_nolock(c,jeb);
462    jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
463
464    spin_unlock(&c->erase_completion_lock);
465
466    return new;
467}
468
469
470void jffs2_complete_reservation(struct jffs2_sb_info *c)
471{
472    D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
473    jffs2_garbage_collect_trigger(c);
474    mutex_unlock(&c->alloc_sem);
475}
476
477static inline int on_list(struct list_head *obj, struct list_head *head)
478{
479    struct list_head *this;
480
481    list_for_each(this, head) {
482        if (this == obj) {
483            D1(printk("%p is on list at %p\n", obj, head));
484            return 1;
485
486        }
487    }
488    return 0;
489}
490
491void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
492{
493    struct jffs2_eraseblock *jeb;
494    int blocknr;
495    struct jffs2_unknown_node n;
496    int ret, addedsize;
497    size_t retlen;
498    uint32_t freed_len;
499
500    if(unlikely(!ref)) {
501        printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
502        return;
503    }
504    if (ref_obsolete(ref)) {
505        D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
506        return;
507    }
508    blocknr = ref->flash_offset / c->sector_size;
509    if (blocknr >= c->nr_blocks) {
510        printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
511        BUG();
512    }
513    jeb = &c->blocks[blocknr];
514
515    if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
516        !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
517        /* Hm. This may confuse static lock analysis. If any of the above
518           three conditions is false, we're going to return from this
519           function without actually obliterating any nodes or freeing
520           any jffs2_raw_node_refs. So we don't need to stop erases from
521           happening, or protect against people holding an obsolete
522           jffs2_raw_node_ref without the erase_completion_lock. */
523        mutex_lock(&c->erase_free_sem);
524    }
525
526    spin_lock(&c->erase_completion_lock);
527
528    freed_len = ref_totlen(c, jeb, ref);
529
530    if (ref_flags(ref) == REF_UNCHECKED) {
531        D1(if (unlikely(jeb->unchecked_size < freed_len)) {
532            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",
533                   freed_len, blocknr, ref->flash_offset, jeb->used_size);
534            BUG();
535        })
536        D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
537        jeb->unchecked_size -= freed_len;
538        c->unchecked_size -= freed_len;
539    } else {
540        D1(if (unlikely(jeb->used_size < freed_len)) {
541            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",
542                   freed_len, blocknr, ref->flash_offset, jeb->used_size);
543            BUG();
544        })
545        D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
546        jeb->used_size -= freed_len;
547        c->used_size -= freed_len;
548    }
549
550    // Take care, that wasted size is taken into concern
551    if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
552        D1(printk("Dirtying\n"));
553        addedsize = freed_len;
554        jeb->dirty_size += freed_len;
555        c->dirty_size += freed_len;
556
557        /* Convert wasted space to dirty, if not a bad block */
558        if (jeb->wasted_size) {
559            if (on_list(&jeb->list, &c->bad_used_list)) {
560                D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
561                      jeb->offset));
562                addedsize = 0; /* To fool the refiling code later */
563            } else {
564                D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
565                      jeb->wasted_size, jeb->offset));
566                addedsize += jeb->wasted_size;
567                jeb->dirty_size += jeb->wasted_size;
568                c->dirty_size += jeb->wasted_size;
569                c->wasted_size -= jeb->wasted_size;
570                jeb->wasted_size = 0;
571            }
572        }
573    } else {
574        D1(printk("Wasting\n"));
575        addedsize = 0;
576        jeb->wasted_size += freed_len;
577        c->wasted_size += freed_len;
578    }
579    ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
580
581    jffs2_dbg_acct_sanity_check_nolock(c, jeb);
582    jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
583
584    if (c->flags & JFFS2_SB_FLAG_SCANNING) {
585        /* Flash scanning is in progress. Don't muck about with the block
586           lists because they're not ready yet, and don't actually
587           obliterate nodes that look obsolete. If they weren't
588           marked obsolete on the flash at the time they _became_
589           obsolete, there was probably a reason for that. */
590        spin_unlock(&c->erase_completion_lock);
591        /* We didn't lock the erase_free_sem */
592        return;
593    }
594
595    if (jeb == c->nextblock) {
596        D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
597    } else if (!jeb->used_size && !jeb->unchecked_size) {
598        if (jeb == c->gcblock) {
599            D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
600            c->gcblock = NULL;
601        } else {
602            D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
603            list_del(&jeb->list);
604        }
605        if (jffs2_wbuf_dirty(c)) {
606            D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
607            list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
608        } else {
609            if (jiffies & 127) {
610                /* Most of the time, we just erase it immediately. Otherwise we
611                   spend ages scanning it on mount, etc. */
612                D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
613                list_add_tail(&jeb->list, &c->erase_pending_list);
614                c->nr_erasing_blocks++;
615                jffs2_erase_pending_trigger(c);
616            } else {
617                /* Sometimes, however, we leave it elsewhere so it doesn't get
618                   immediately reused, and we spread the load a bit. */
619                D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
620                list_add_tail(&jeb->list, &c->erasable_list);
621            }
622        }
623        D1(printk(KERN_DEBUG "Done OK\n"));
624    } else if (jeb == c->gcblock) {
625        D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
626    } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
627        D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
628        list_del(&jeb->list);
629        D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
630        list_add_tail(&jeb->list, &c->dirty_list);
631    } else if (VERYDIRTY(c, jeb->dirty_size) &&
632           !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
633        D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
634        list_del(&jeb->list);
635        D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
636        list_add_tail(&jeb->list, &c->very_dirty_list);
637    } else {
638        D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
639              jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
640    }
641
642    spin_unlock(&c->erase_completion_lock);
643
644    if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
645        (c->flags & JFFS2_SB_FLAG_BUILDING)) {
646        /* We didn't lock the erase_free_sem */
647        return;
648    }
649
650    /* The erase_free_sem is locked, and has been since before we marked the node obsolete
651       and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
652       the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
653       by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
654
655    D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
656    ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
657    if (ret) {
658        printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
659        goto out_erase_sem;
660    }
661    if (retlen != sizeof(n)) {
662        printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
663        goto out_erase_sem;
664    }
665    if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
666        printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
667        goto out_erase_sem;
668    }
669    if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
670        D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
671        goto out_erase_sem;
672    }
673    /* XXX FIXME: This is ugly now */
674    n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
675    ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
676    if (ret) {
677        printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
678        goto out_erase_sem;
679    }
680    if (retlen != sizeof(n)) {
681        printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
682        goto out_erase_sem;
683    }
684
685    /* Nodes which have been marked obsolete no longer need to be
686       associated with any inode. Remove them from the per-inode list.
687
688       Note we can't do this for NAND at the moment because we need
689       obsolete dirent nodes to stay on the lists, because of the
690       horridness in jffs2_garbage_collect_deletion_dirent(). Also
691       because we delete the inocache, and on NAND we need that to
692       stay around until all the nodes are actually erased, in order
693       to stop us from giving the same inode number to another newly
694       created inode. */
695    if (ref->next_in_ino) {
696        struct jffs2_inode_cache *ic;
697        struct jffs2_raw_node_ref **p;
698
699        spin_lock(&c->erase_completion_lock);
700
701        ic = jffs2_raw_ref_to_ic(ref);
702        for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
703            ;
704
705        *p = ref->next_in_ino;
706        ref->next_in_ino = NULL;
707
708        switch (ic->class) {
709#ifdef CONFIG_JFFS2_FS_XATTR
710            case RAWNODE_CLASS_XATTR_DATUM:
711                jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
712                break;
713            case RAWNODE_CLASS_XATTR_REF:
714                jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
715                break;
716#endif
717            default:
718                if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
719                    jffs2_del_ino_cache(c, ic);
720                break;
721        }
722        spin_unlock(&c->erase_completion_lock);
723    }
724
725 out_erase_sem:
726    mutex_unlock(&c->erase_free_sem);
727}
728
729int jffs2_thread_should_wake(struct jffs2_sb_info *c)
730{
731    int ret = 0;
732    uint32_t dirty;
733    int nr_very_dirty = 0;
734    struct jffs2_eraseblock *jeb;
735
736    if (c->unchecked_size) {
737        D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
738              c->unchecked_size, c->checked_ino));
739        return 1;
740    }
741
742    /* dirty_size contains blocks on erase_pending_list
743     * those blocks are counted in c->nr_erasing_blocks.
744     * If one block is actually erased, it is not longer counted as dirty_space
745     * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
746     * with c->nr_erasing_blocks * c->sector_size again.
747     * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
748     * This helps us to force gc and pick eventually a clean block to spread the load.
749     */
750    dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
751
752    if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
753            (dirty > c->nospc_dirty_size))
754        ret = 1;
755
756    list_for_each_entry(jeb, &c->very_dirty_list, list) {
757        nr_very_dirty++;
758        if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
759            ret = 1;
760            /* In debug mode, actually go through and count them all */
761            D1(continue);
762            break;
763        }
764    }
765
766    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",
767          c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, nr_very_dirty, ret?"yes":"no"));
768
769    return ret;
770}
771

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