Blackfin/ipipe: fix deferred pipeline sync for the root stage
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / jffs2 / gc.c
blob31dce611337cffcf67e8330bb2f6b6e8608bde1e
1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
7 * Created by David Woodhouse <dwmw2@infradead.org>
9 * For licensing information, see the file 'LICENCE' in this directory.
13 #include <linux/kernel.h>
14 #include <linux/mtd/mtd.h>
15 #include <linux/slab.h>
16 #include <linux/pagemap.h>
17 #include <linux/crc32.h>
18 #include <linux/compiler.h>
19 #include <linux/stat.h>
20 #include "nodelist.h"
21 #include "compr.h"
23 static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
24 struct jffs2_inode_cache *ic,
25 struct jffs2_raw_node_ref *raw);
26 static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
27 struct jffs2_inode_info *f, struct jffs2_full_dnode *fd);
28 static int jffs2_garbage_collect_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
29 struct jffs2_inode_info *f, struct jffs2_full_dirent *fd);
30 static int jffs2_garbage_collect_deletion_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
31 struct jffs2_inode_info *f, struct jffs2_full_dirent *fd);
32 static int jffs2_garbage_collect_hole(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
33 struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
34 uint32_t start, uint32_t end);
35 static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
36 struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
37 uint32_t start, uint32_t end);
38 static int jffs2_garbage_collect_live(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
39 struct jffs2_raw_node_ref *raw, struct jffs2_inode_info *f);
41 /* Called with erase_completion_lock held */
42 static struct jffs2_eraseblock *jffs2_find_gc_block(struct jffs2_sb_info *c)
44 struct jffs2_eraseblock *ret;
45 struct list_head *nextlist = NULL;
46 int n = jiffies % 128;
48 /* Pick an eraseblock to garbage collect next. This is where we'll
49 put the clever wear-levelling algorithms. Eventually. */
50 /* We possibly want to favour the dirtier blocks more when the
51 number of free blocks is low. */
52 again:
53 if (!list_empty(&c->bad_used_list) && c->nr_free_blocks > c->resv_blocks_gcbad) {
54 D1(printk(KERN_DEBUG "Picking block from bad_used_list to GC next\n"));
55 nextlist = &c->bad_used_list;
56 } else if (n < 50 && !list_empty(&c->erasable_list)) {
57 /* Note that most of them will have gone directly to be erased.
58 So don't favour the erasable_list _too_ much. */
59 D1(printk(KERN_DEBUG "Picking block from erasable_list to GC next\n"));
60 nextlist = &c->erasable_list;
61 } else if (n < 110 && !list_empty(&c->very_dirty_list)) {
62 /* Most of the time, pick one off the very_dirty list */
63 D1(printk(KERN_DEBUG "Picking block from very_dirty_list to GC next\n"));
64 nextlist = &c->very_dirty_list;
65 } else if (n < 126 && !list_empty(&c->dirty_list)) {
66 D1(printk(KERN_DEBUG "Picking block from dirty_list to GC next\n"));
67 nextlist = &c->dirty_list;
68 } else if (!list_empty(&c->clean_list)) {
69 D1(printk(KERN_DEBUG "Picking block from clean_list to GC next\n"));
70 nextlist = &c->clean_list;
71 } else if (!list_empty(&c->dirty_list)) {
72 D1(printk(KERN_DEBUG "Picking block from dirty_list to GC next (clean_list was empty)\n"));
74 nextlist = &c->dirty_list;
75 } else if (!list_empty(&c->very_dirty_list)) {
76 D1(printk(KERN_DEBUG "Picking block from very_dirty_list to GC next (clean_list and dirty_list were empty)\n"));
77 nextlist = &c->very_dirty_list;
78 } else if (!list_empty(&c->erasable_list)) {
79 D1(printk(KERN_DEBUG "Picking block from erasable_list to GC next (clean_list and {very_,}dirty_list were empty)\n"));
81 nextlist = &c->erasable_list;
82 } else if (!list_empty(&c->erasable_pending_wbuf_list)) {
83 /* There are blocks are wating for the wbuf sync */
84 D1(printk(KERN_DEBUG "Synching wbuf in order to reuse erasable_pending_wbuf_list blocks\n"));
85 spin_unlock(&c->erase_completion_lock);
86 jffs2_flush_wbuf_pad(c);
87 spin_lock(&c->erase_completion_lock);
88 goto again;
89 } else {
90 /* Eep. All were empty */
91 D1(printk(KERN_NOTICE "jffs2: No clean, dirty _or_ erasable blocks to GC from! Where are they all?\n"));
92 return NULL;
95 ret = list_entry(nextlist->next, struct jffs2_eraseblock, list);
96 list_del(&ret->list);
97 c->gcblock = ret;
98 ret->gc_node = ret->first_node;
99 if (!ret->gc_node) {
100 printk(KERN_WARNING "Eep. ret->gc_node for block at 0x%08x is NULL\n", ret->offset);
101 BUG();
104 /* Have we accidentally picked a clean block with wasted space ? */
105 if (ret->wasted_size) {
106 D1(printk(KERN_DEBUG "Converting wasted_size %08x to dirty_size\n", ret->wasted_size));
107 ret->dirty_size += ret->wasted_size;
108 c->wasted_size -= ret->wasted_size;
109 c->dirty_size += ret->wasted_size;
110 ret->wasted_size = 0;
113 return ret;
116 /* jffs2_garbage_collect_pass
117 * Make a single attempt to progress GC. Move one node, and possibly
118 * start erasing one eraseblock.
120 int jffs2_garbage_collect_pass(struct jffs2_sb_info *c)
122 struct jffs2_inode_info *f;
123 struct jffs2_inode_cache *ic;
124 struct jffs2_eraseblock *jeb;
125 struct jffs2_raw_node_ref *raw;
126 uint32_t gcblock_dirty;
127 int ret = 0, inum, nlink;
128 int xattr = 0;
130 if (mutex_lock_interruptible(&c->alloc_sem))
131 return -EINTR;
133 for (;;) {
134 spin_lock(&c->erase_completion_lock);
135 if (!c->unchecked_size)
136 break;
138 /* We can't start doing GC yet. We haven't finished checking
139 the node CRCs etc. Do it now. */
141 /* checked_ino is protected by the alloc_sem */
142 if (c->checked_ino > c->highest_ino && xattr) {
143 printk(KERN_CRIT "Checked all inodes but still 0x%x bytes of unchecked space?\n",
144 c->unchecked_size);
145 jffs2_dbg_dump_block_lists_nolock(c);
146 spin_unlock(&c->erase_completion_lock);
147 mutex_unlock(&c->alloc_sem);
148 return -ENOSPC;
151 spin_unlock(&c->erase_completion_lock);
153 if (!xattr)
154 xattr = jffs2_verify_xattr(c);
156 spin_lock(&c->inocache_lock);
158 ic = jffs2_get_ino_cache(c, c->checked_ino++);
160 if (!ic) {
161 spin_unlock(&c->inocache_lock);
162 continue;
165 if (!ic->pino_nlink) {
166 D1(printk(KERN_DEBUG "Skipping check of ino #%d with nlink/pino zero\n",
167 ic->ino));
168 spin_unlock(&c->inocache_lock);
169 jffs2_xattr_delete_inode(c, ic);
170 continue;
172 switch(ic->state) {
173 case INO_STATE_CHECKEDABSENT:
174 case INO_STATE_PRESENT:
175 D1(printk(KERN_DEBUG "Skipping ino #%u already checked\n", ic->ino));
176 spin_unlock(&c->inocache_lock);
177 continue;
179 case INO_STATE_GC:
180 case INO_STATE_CHECKING:
181 printk(KERN_WARNING "Inode #%u is in state %d during CRC check phase!\n", ic->ino, ic->state);
182 spin_unlock(&c->inocache_lock);
183 BUG();
185 case INO_STATE_READING:
186 /* We need to wait for it to finish, lest we move on
187 and trigger the BUG() above while we haven't yet
188 finished checking all its nodes */
189 D1(printk(KERN_DEBUG "Waiting for ino #%u to finish reading\n", ic->ino));
190 /* We need to come back again for the _same_ inode. We've
191 made no progress in this case, but that should be OK */
192 c->checked_ino--;
194 mutex_unlock(&c->alloc_sem);
195 sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
196 return 0;
198 default:
199 BUG();
201 case INO_STATE_UNCHECKED:
204 ic->state = INO_STATE_CHECKING;
205 spin_unlock(&c->inocache_lock);
207 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() triggering inode scan of ino#%u\n", ic->ino));
209 ret = jffs2_do_crccheck_inode(c, ic);
210 if (ret)
211 printk(KERN_WARNING "Returned error for crccheck of ino #%u. Expect badness...\n", ic->ino);
213 jffs2_set_inocache_state(c, ic, INO_STATE_CHECKEDABSENT);
214 mutex_unlock(&c->alloc_sem);
215 return ret;
218 /* If there are any blocks which need erasing, erase them now */
219 if (!list_empty(&c->erase_complete_list) ||
220 !list_empty(&c->erase_pending_list)) {
221 spin_unlock(&c->erase_completion_lock);
222 mutex_unlock(&c->alloc_sem);
223 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() erasing pending blocks\n"));
224 if (jffs2_erase_pending_blocks(c, 1))
225 return 0;
227 D1(printk(KERN_DEBUG "No progress from erasing blocks; doing GC anyway\n"));
228 spin_lock(&c->erase_completion_lock);
229 mutex_lock(&c->alloc_sem);
232 /* First, work out which block we're garbage-collecting */
233 jeb = c->gcblock;
235 if (!jeb)
236 jeb = jffs2_find_gc_block(c);
238 if (!jeb) {
239 /* Couldn't find a free block. But maybe we can just erase one and make 'progress'? */
240 if (c->nr_erasing_blocks) {
241 spin_unlock(&c->erase_completion_lock);
242 mutex_unlock(&c->alloc_sem);
243 return -EAGAIN;
245 D1(printk(KERN_NOTICE "jffs2: Couldn't find erase block to garbage collect!\n"));
246 spin_unlock(&c->erase_completion_lock);
247 mutex_unlock(&c->alloc_sem);
248 return -EIO;
251 D1(printk(KERN_DEBUG "GC from block %08x, used_size %08x, dirty_size %08x, free_size %08x\n", jeb->offset, jeb->used_size, jeb->dirty_size, jeb->free_size));
252 D1(if (c->nextblock)
253 printk(KERN_DEBUG "Nextblock at %08x, used_size %08x, dirty_size %08x, wasted_size %08x, free_size %08x\n", c->nextblock->offset, c->nextblock->used_size, c->nextblock->dirty_size, c->nextblock->wasted_size, c->nextblock->free_size));
255 if (!jeb->used_size) {
256 mutex_unlock(&c->alloc_sem);
257 goto eraseit;
260 raw = jeb->gc_node;
261 gcblock_dirty = jeb->dirty_size;
263 while(ref_obsolete(raw)) {
264 D1(printk(KERN_DEBUG "Node at 0x%08x is obsolete... skipping\n", ref_offset(raw)));
265 raw = ref_next(raw);
266 if (unlikely(!raw)) {
267 printk(KERN_WARNING "eep. End of raw list while still supposedly nodes to GC\n");
268 printk(KERN_WARNING "erase block at 0x%08x. free_size 0x%08x, dirty_size 0x%08x, used_size 0x%08x\n",
269 jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size);
270 jeb->gc_node = raw;
271 spin_unlock(&c->erase_completion_lock);
272 mutex_unlock(&c->alloc_sem);
273 BUG();
276 jeb->gc_node = raw;
278 D1(printk(KERN_DEBUG "Going to garbage collect node at 0x%08x\n", ref_offset(raw)));
280 if (!raw->next_in_ino) {
281 /* Inode-less node. Clean marker, snapshot or something like that */
282 spin_unlock(&c->erase_completion_lock);
283 if (ref_flags(raw) == REF_PRISTINE) {
284 /* It's an unknown node with JFFS2_FEATURE_RWCOMPAT_COPY */
285 jffs2_garbage_collect_pristine(c, NULL, raw);
286 } else {
287 /* Just mark it obsolete */
288 jffs2_mark_node_obsolete(c, raw);
290 mutex_unlock(&c->alloc_sem);
291 goto eraseit_lock;
294 ic = jffs2_raw_ref_to_ic(raw);
296 #ifdef CONFIG_JFFS2_FS_XATTR
297 /* When 'ic' refers xattr_datum/xattr_ref, this node is GCed as xattr.
298 * We can decide whether this node is inode or xattr by ic->class. */
299 if (ic->class == RAWNODE_CLASS_XATTR_DATUM
300 || ic->class == RAWNODE_CLASS_XATTR_REF) {
301 spin_unlock(&c->erase_completion_lock);
303 if (ic->class == RAWNODE_CLASS_XATTR_DATUM) {
304 ret = jffs2_garbage_collect_xattr_datum(c, (struct jffs2_xattr_datum *)ic, raw);
305 } else {
306 ret = jffs2_garbage_collect_xattr_ref(c, (struct jffs2_xattr_ref *)ic, raw);
308 goto test_gcnode;
310 #endif
312 /* We need to hold the inocache. Either the erase_completion_lock or
313 the inocache_lock are sufficient; we trade down since the inocache_lock
314 causes less contention. */
315 spin_lock(&c->inocache_lock);
317 spin_unlock(&c->erase_completion_lock);
319 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass collecting from block @0x%08x. Node @0x%08x(%d), ino #%u\n", jeb->offset, ref_offset(raw), ref_flags(raw), ic->ino));
321 /* Three possibilities:
322 1. Inode is already in-core. We must iget it and do proper
323 updating to its fragtree, etc.
324 2. Inode is not in-core, node is REF_PRISTINE. We lock the
325 inocache to prevent a read_inode(), copy the node intact.
326 3. Inode is not in-core, node is not pristine. We must iget()
327 and take the slow path.
330 switch(ic->state) {
331 case INO_STATE_CHECKEDABSENT:
332 /* It's been checked, but it's not currently in-core.
333 We can just copy any pristine nodes, but have
334 to prevent anyone else from doing read_inode() while
335 we're at it, so we set the state accordingly */
336 if (ref_flags(raw) == REF_PRISTINE)
337 ic->state = INO_STATE_GC;
338 else {
339 D1(printk(KERN_DEBUG "Ino #%u is absent but node not REF_PRISTINE. Reading.\n",
340 ic->ino));
342 break;
344 case INO_STATE_PRESENT:
345 /* It's in-core. GC must iget() it. */
346 break;
348 case INO_STATE_UNCHECKED:
349 case INO_STATE_CHECKING:
350 case INO_STATE_GC:
351 /* Should never happen. We should have finished checking
352 by the time we actually start doing any GC, and since
353 we're holding the alloc_sem, no other garbage collection
354 can happen.
356 printk(KERN_CRIT "Inode #%u already in state %d in jffs2_garbage_collect_pass()!\n",
357 ic->ino, ic->state);
358 mutex_unlock(&c->alloc_sem);
359 spin_unlock(&c->inocache_lock);
360 BUG();
362 case INO_STATE_READING:
363 /* Someone's currently trying to read it. We must wait for
364 them to finish and then go through the full iget() route
365 to do the GC. However, sometimes read_inode() needs to get
366 the alloc_sem() (for marking nodes invalid) so we must
367 drop the alloc_sem before sleeping. */
369 mutex_unlock(&c->alloc_sem);
370 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() waiting for ino #%u in state %d\n",
371 ic->ino, ic->state));
372 sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
373 /* And because we dropped the alloc_sem we must start again from the
374 beginning. Ponder chance of livelock here -- we're returning success
375 without actually making any progress.
377 Q: What are the chances that the inode is back in INO_STATE_READING
378 again by the time we next enter this function? And that this happens
379 enough times to cause a real delay?
381 A: Small enough that I don't care :)
383 return 0;
386 /* OK. Now if the inode is in state INO_STATE_GC, we are going to copy the
387 node intact, and we don't have to muck about with the fragtree etc.
388 because we know it's not in-core. If it _was_ in-core, we go through
389 all the iget() crap anyway */
391 if (ic->state == INO_STATE_GC) {
392 spin_unlock(&c->inocache_lock);
394 ret = jffs2_garbage_collect_pristine(c, ic, raw);
396 spin_lock(&c->inocache_lock);
397 ic->state = INO_STATE_CHECKEDABSENT;
398 wake_up(&c->inocache_wq);
400 if (ret != -EBADFD) {
401 spin_unlock(&c->inocache_lock);
402 goto test_gcnode;
405 /* Fall through if it wanted us to, with inocache_lock held */
408 /* Prevent the fairly unlikely race where the gcblock is
409 entirely obsoleted by the final close of a file which had
410 the only valid nodes in the block, followed by erasure,
411 followed by freeing of the ic because the erased block(s)
412 held _all_ the nodes of that inode.... never been seen but
413 it's vaguely possible. */
415 inum = ic->ino;
416 nlink = ic->pino_nlink;
417 spin_unlock(&c->inocache_lock);
419 f = jffs2_gc_fetch_inode(c, inum, !nlink);
420 if (IS_ERR(f)) {
421 ret = PTR_ERR(f);
422 goto release_sem;
424 if (!f) {
425 ret = 0;
426 goto release_sem;
429 ret = jffs2_garbage_collect_live(c, jeb, raw, f);
431 jffs2_gc_release_inode(c, f);
433 test_gcnode:
434 if (jeb->dirty_size == gcblock_dirty && !ref_obsolete(jeb->gc_node)) {
435 /* Eep. This really should never happen. GC is broken */
436 printk(KERN_ERR "Error garbage collecting node at %08x!\n", ref_offset(jeb->gc_node));
437 ret = -ENOSPC;
439 release_sem:
440 mutex_unlock(&c->alloc_sem);
442 eraseit_lock:
443 /* If we've finished this block, start it erasing */
444 spin_lock(&c->erase_completion_lock);
446 eraseit:
447 if (c->gcblock && !c->gcblock->used_size) {
448 D1(printk(KERN_DEBUG "Block at 0x%08x completely obsoleted by GC. Moving to erase_pending_list\n", c->gcblock->offset));
449 /* We're GC'ing an empty block? */
450 list_add_tail(&c->gcblock->list, &c->erase_pending_list);
451 c->gcblock = NULL;
452 c->nr_erasing_blocks++;
453 jffs2_garbage_collect_trigger(c);
455 spin_unlock(&c->erase_completion_lock);
457 return ret;
460 static int jffs2_garbage_collect_live(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
461 struct jffs2_raw_node_ref *raw, struct jffs2_inode_info *f)
463 struct jffs2_node_frag *frag;
464 struct jffs2_full_dnode *fn = NULL;
465 struct jffs2_full_dirent *fd;
466 uint32_t start = 0, end = 0, nrfrags = 0;
467 int ret = 0;
469 mutex_lock(&f->sem);
471 /* Now we have the lock for this inode. Check that it's still the one at the head
472 of the list. */
474 spin_lock(&c->erase_completion_lock);
476 if (c->gcblock != jeb) {
477 spin_unlock(&c->erase_completion_lock);
478 D1(printk(KERN_DEBUG "GC block is no longer gcblock. Restart\n"));
479 goto upnout;
481 if (ref_obsolete(raw)) {
482 spin_unlock(&c->erase_completion_lock);
483 D1(printk(KERN_DEBUG "node to be GC'd was obsoleted in the meantime.\n"));
484 /* They'll call again */
485 goto upnout;
487 spin_unlock(&c->erase_completion_lock);
489 /* OK. Looks safe. And nobody can get us now because we have the semaphore. Move the block */
490 if (f->metadata && f->metadata->raw == raw) {
491 fn = f->metadata;
492 ret = jffs2_garbage_collect_metadata(c, jeb, f, fn);
493 goto upnout;
496 /* FIXME. Read node and do lookup? */
497 for (frag = frag_first(&f->fragtree); frag; frag = frag_next(frag)) {
498 if (frag->node && frag->node->raw == raw) {
499 fn = frag->node;
500 end = frag->ofs + frag->size;
501 if (!nrfrags++)
502 start = frag->ofs;
503 if (nrfrags == frag->node->frags)
504 break; /* We've found them all */
507 if (fn) {
508 if (ref_flags(raw) == REF_PRISTINE) {
509 ret = jffs2_garbage_collect_pristine(c, f->inocache, raw);
510 if (!ret) {
511 /* Urgh. Return it sensibly. */
512 frag->node->raw = f->inocache->nodes;
514 if (ret != -EBADFD)
515 goto upnout;
517 /* We found a datanode. Do the GC */
518 if((start >> PAGE_CACHE_SHIFT) < ((end-1) >> PAGE_CACHE_SHIFT)) {
519 /* It crosses a page boundary. Therefore, it must be a hole. */
520 ret = jffs2_garbage_collect_hole(c, jeb, f, fn, start, end);
521 } else {
522 /* It could still be a hole. But we GC the page this way anyway */
523 ret = jffs2_garbage_collect_dnode(c, jeb, f, fn, start, end);
525 goto upnout;
528 /* Wasn't a dnode. Try dirent */
529 for (fd = f->dents; fd; fd=fd->next) {
530 if (fd->raw == raw)
531 break;
534 if (fd && fd->ino) {
535 ret = jffs2_garbage_collect_dirent(c, jeb, f, fd);
536 } else if (fd) {
537 ret = jffs2_garbage_collect_deletion_dirent(c, jeb, f, fd);
538 } else {
539 printk(KERN_WARNING "Raw node at 0x%08x wasn't in node lists for ino #%u\n",
540 ref_offset(raw), f->inocache->ino);
541 if (ref_obsolete(raw)) {
542 printk(KERN_WARNING "But it's obsolete so we don't mind too much\n");
543 } else {
544 jffs2_dbg_dump_node(c, ref_offset(raw));
545 BUG();
548 upnout:
549 mutex_unlock(&f->sem);
551 return ret;
554 static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
555 struct jffs2_inode_cache *ic,
556 struct jffs2_raw_node_ref *raw)
558 union jffs2_node_union *node;
559 size_t retlen;
560 int ret;
561 uint32_t phys_ofs, alloclen;
562 uint32_t crc, rawlen;
563 int retried = 0;
565 D1(printk(KERN_DEBUG "Going to GC REF_PRISTINE node at 0x%08x\n", ref_offset(raw)));
567 alloclen = rawlen = ref_totlen(c, c->gcblock, raw);
569 /* Ask for a small amount of space (or the totlen if smaller) because we
570 don't want to force wastage of the end of a block if splitting would
571 work. */
572 if (ic && alloclen > sizeof(struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN)
573 alloclen = sizeof(struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN;
575 ret = jffs2_reserve_space_gc(c, alloclen, &alloclen, rawlen);
576 /* 'rawlen' is not the exact summary size; it is only an upper estimation */
578 if (ret)
579 return ret;
581 if (alloclen < rawlen) {
582 /* Doesn't fit untouched. We'll go the old route and split it */
583 return -EBADFD;
586 node = kmalloc(rawlen, GFP_KERNEL);
587 if (!node)
588 return -ENOMEM;
590 ret = jffs2_flash_read(c, ref_offset(raw), rawlen, &retlen, (char *)node);
591 if (!ret && retlen != rawlen)
592 ret = -EIO;
593 if (ret)
594 goto out_node;
596 crc = crc32(0, node, sizeof(struct jffs2_unknown_node)-4);
597 if (je32_to_cpu(node->u.hdr_crc) != crc) {
598 printk(KERN_WARNING "Header CRC failed on REF_PRISTINE node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
599 ref_offset(raw), je32_to_cpu(node->u.hdr_crc), crc);
600 goto bail;
603 switch(je16_to_cpu(node->u.nodetype)) {
604 case JFFS2_NODETYPE_INODE:
605 crc = crc32(0, node, sizeof(node->i)-8);
606 if (je32_to_cpu(node->i.node_crc) != crc) {
607 printk(KERN_WARNING "Node CRC failed on REF_PRISTINE data node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
608 ref_offset(raw), je32_to_cpu(node->i.node_crc), crc);
609 goto bail;
612 if (je32_to_cpu(node->i.dsize)) {
613 crc = crc32(0, node->i.data, je32_to_cpu(node->i.csize));
614 if (je32_to_cpu(node->i.data_crc) != crc) {
615 printk(KERN_WARNING "Data CRC failed on REF_PRISTINE data node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
616 ref_offset(raw), je32_to_cpu(node->i.data_crc), crc);
617 goto bail;
620 break;
622 case JFFS2_NODETYPE_DIRENT:
623 crc = crc32(0, node, sizeof(node->d)-8);
624 if (je32_to_cpu(node->d.node_crc) != crc) {
625 printk(KERN_WARNING "Node CRC failed on REF_PRISTINE dirent node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
626 ref_offset(raw), je32_to_cpu(node->d.node_crc), crc);
627 goto bail;
630 if (strnlen(node->d.name, node->d.nsize) != node->d.nsize) {
631 printk(KERN_WARNING "Name in dirent node at 0x%08x contains zeroes\n", ref_offset(raw));
632 goto bail;
635 if (node->d.nsize) {
636 crc = crc32(0, node->d.name, node->d.nsize);
637 if (je32_to_cpu(node->d.name_crc) != crc) {
638 printk(KERN_WARNING "Name CRC failed on REF_PRISTINE dirent node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
639 ref_offset(raw), je32_to_cpu(node->d.name_crc), crc);
640 goto bail;
643 break;
644 default:
645 /* If it's inode-less, we don't _know_ what it is. Just copy it intact */
646 if (ic) {
647 printk(KERN_WARNING "Unknown node type for REF_PRISTINE node at 0x%08x: 0x%04x\n",
648 ref_offset(raw), je16_to_cpu(node->u.nodetype));
649 goto bail;
653 /* OK, all the CRCs are good; this node can just be copied as-is. */
654 retry:
655 phys_ofs = write_ofs(c);
657 ret = jffs2_flash_write(c, phys_ofs, rawlen, &retlen, (char *)node);
659 if (ret || (retlen != rawlen)) {
660 printk(KERN_NOTICE "Write of %d bytes at 0x%08x failed. returned %d, retlen %zd\n",
661 rawlen, phys_ofs, ret, retlen);
662 if (retlen) {
663 jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, rawlen, NULL);
664 } else {
665 printk(KERN_NOTICE "Not marking the space at 0x%08x as dirty because the flash driver returned retlen zero\n", phys_ofs);
667 if (!retried) {
668 /* Try to reallocate space and retry */
669 uint32_t dummy;
670 struct jffs2_eraseblock *jeb = &c->blocks[phys_ofs / c->sector_size];
672 retried = 1;
674 D1(printk(KERN_DEBUG "Retrying failed write of REF_PRISTINE node.\n"));
676 jffs2_dbg_acct_sanity_check(c,jeb);
677 jffs2_dbg_acct_paranoia_check(c, jeb);
679 ret = jffs2_reserve_space_gc(c, rawlen, &dummy, rawlen);
680 /* this is not the exact summary size of it,
681 it is only an upper estimation */
683 if (!ret) {
684 D1(printk(KERN_DEBUG "Allocated space at 0x%08x to retry failed write.\n", phys_ofs));
686 jffs2_dbg_acct_sanity_check(c,jeb);
687 jffs2_dbg_acct_paranoia_check(c, jeb);
689 goto retry;
691 D1(printk(KERN_DEBUG "Failed to allocate space to retry failed write: %d!\n", ret));
694 if (!ret)
695 ret = -EIO;
696 goto out_node;
698 jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, rawlen, ic);
700 jffs2_mark_node_obsolete(c, raw);
701 D1(printk(KERN_DEBUG "WHEEE! GC REF_PRISTINE node at 0x%08x succeeded\n", ref_offset(raw)));
703 out_node:
704 kfree(node);
705 return ret;
706 bail:
707 ret = -EBADFD;
708 goto out_node;
711 static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
712 struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
714 struct jffs2_full_dnode *new_fn;
715 struct jffs2_raw_inode ri;
716 struct jffs2_node_frag *last_frag;
717 union jffs2_device_node dev;
718 char *mdata = NULL;
719 int mdatalen = 0;
720 uint32_t alloclen, ilen;
721 int ret;
723 if (S_ISBLK(JFFS2_F_I_MODE(f)) ||
724 S_ISCHR(JFFS2_F_I_MODE(f)) ) {
725 /* For these, we don't actually need to read the old node */
726 mdatalen = jffs2_encode_dev(&dev, JFFS2_F_I_RDEV(f));
727 mdata = (char *)&dev;
728 D1(printk(KERN_DEBUG "jffs2_garbage_collect_metadata(): Writing %d bytes of kdev_t\n", mdatalen));
729 } else if (S_ISLNK(JFFS2_F_I_MODE(f))) {
730 mdatalen = fn->size;
731 mdata = kmalloc(fn->size, GFP_KERNEL);
732 if (!mdata) {
733 printk(KERN_WARNING "kmalloc of mdata failed in jffs2_garbage_collect_metadata()\n");
734 return -ENOMEM;
736 ret = jffs2_read_dnode(c, f, fn, mdata, 0, mdatalen);
737 if (ret) {
738 printk(KERN_WARNING "read of old metadata failed in jffs2_garbage_collect_metadata(): %d\n", ret);
739 kfree(mdata);
740 return ret;
742 D1(printk(KERN_DEBUG "jffs2_garbage_collect_metadata(): Writing %d bites of symlink target\n", mdatalen));
746 ret = jffs2_reserve_space_gc(c, sizeof(ri) + mdatalen, &alloclen,
747 JFFS2_SUMMARY_INODE_SIZE);
748 if (ret) {
749 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_metadata failed: %d\n",
750 sizeof(ri)+ mdatalen, ret);
751 goto out;
754 last_frag = frag_last(&f->fragtree);
755 if (last_frag)
756 /* Fetch the inode length from the fragtree rather then
757 * from i_size since i_size may have not been updated yet */
758 ilen = last_frag->ofs + last_frag->size;
759 else
760 ilen = JFFS2_F_I_SIZE(f);
762 memset(&ri, 0, sizeof(ri));
763 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
764 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
765 ri.totlen = cpu_to_je32(sizeof(ri) + mdatalen);
766 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
768 ri.ino = cpu_to_je32(f->inocache->ino);
769 ri.version = cpu_to_je32(++f->highest_version);
770 ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
771 ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
772 ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
773 ri.isize = cpu_to_je32(ilen);
774 ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
775 ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
776 ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
777 ri.offset = cpu_to_je32(0);
778 ri.csize = cpu_to_je32(mdatalen);
779 ri.dsize = cpu_to_je32(mdatalen);
780 ri.compr = JFFS2_COMPR_NONE;
781 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
782 ri.data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
784 new_fn = jffs2_write_dnode(c, f, &ri, mdata, mdatalen, ALLOC_GC);
786 if (IS_ERR(new_fn)) {
787 printk(KERN_WARNING "Error writing new dnode: %ld\n", PTR_ERR(new_fn));
788 ret = PTR_ERR(new_fn);
789 goto out;
791 jffs2_mark_node_obsolete(c, fn->raw);
792 jffs2_free_full_dnode(fn);
793 f->metadata = new_fn;
794 out:
795 if (S_ISLNK(JFFS2_F_I_MODE(f)))
796 kfree(mdata);
797 return ret;
800 static int jffs2_garbage_collect_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
801 struct jffs2_inode_info *f, struct jffs2_full_dirent *fd)
803 struct jffs2_full_dirent *new_fd;
804 struct jffs2_raw_dirent rd;
805 uint32_t alloclen;
806 int ret;
808 rd.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
809 rd.nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
810 rd.nsize = strlen(fd->name);
811 rd.totlen = cpu_to_je32(sizeof(rd) + rd.nsize);
812 rd.hdr_crc = cpu_to_je32(crc32(0, &rd, sizeof(struct jffs2_unknown_node)-4));
814 rd.pino = cpu_to_je32(f->inocache->ino);
815 rd.version = cpu_to_je32(++f->highest_version);
816 rd.ino = cpu_to_je32(fd->ino);
817 /* If the times on this inode were set by explicit utime() they can be different,
818 so refrain from splatting them. */
819 if (JFFS2_F_I_MTIME(f) == JFFS2_F_I_CTIME(f))
820 rd.mctime = cpu_to_je32(JFFS2_F_I_MTIME(f));
821 else
822 rd.mctime = cpu_to_je32(0);
823 rd.type = fd->type;
824 rd.node_crc = cpu_to_je32(crc32(0, &rd, sizeof(rd)-8));
825 rd.name_crc = cpu_to_je32(crc32(0, fd->name, rd.nsize));
827 ret = jffs2_reserve_space_gc(c, sizeof(rd)+rd.nsize, &alloclen,
828 JFFS2_SUMMARY_DIRENT_SIZE(rd.nsize));
829 if (ret) {
830 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dirent failed: %d\n",
831 sizeof(rd)+rd.nsize, ret);
832 return ret;
834 new_fd = jffs2_write_dirent(c, f, &rd, fd->name, rd.nsize, ALLOC_GC);
836 if (IS_ERR(new_fd)) {
837 printk(KERN_WARNING "jffs2_write_dirent in garbage_collect_dirent failed: %ld\n", PTR_ERR(new_fd));
838 return PTR_ERR(new_fd);
840 jffs2_add_fd_to_list(c, new_fd, &f->dents);
841 return 0;
844 static int jffs2_garbage_collect_deletion_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
845 struct jffs2_inode_info *f, struct jffs2_full_dirent *fd)
847 struct jffs2_full_dirent **fdp = &f->dents;
848 int found = 0;
850 /* On a medium where we can't actually mark nodes obsolete
851 pernamently, such as NAND flash, we need to work out
852 whether this deletion dirent is still needed to actively
853 delete a 'real' dirent with the same name that's still
854 somewhere else on the flash. */
855 if (!jffs2_can_mark_obsolete(c)) {
856 struct jffs2_raw_dirent *rd;
857 struct jffs2_raw_node_ref *raw;
858 int ret;
859 size_t retlen;
860 int name_len = strlen(fd->name);
861 uint32_t name_crc = crc32(0, fd->name, name_len);
862 uint32_t rawlen = ref_totlen(c, jeb, fd->raw);
864 rd = kmalloc(rawlen, GFP_KERNEL);
865 if (!rd)
866 return -ENOMEM;
868 /* Prevent the erase code from nicking the obsolete node refs while
869 we're looking at them. I really don't like this extra lock but
870 can't see any alternative. Suggestions on a postcard to... */
871 mutex_lock(&c->erase_free_sem);
873 for (raw = f->inocache->nodes; raw != (void *)f->inocache; raw = raw->next_in_ino) {
875 cond_resched();
877 /* We only care about obsolete ones */
878 if (!(ref_obsolete(raw)))
879 continue;
881 /* Any dirent with the same name is going to have the same length... */
882 if (ref_totlen(c, NULL, raw) != rawlen)
883 continue;
885 /* Doesn't matter if there's one in the same erase block. We're going to
886 delete it too at the same time. */
887 if (SECTOR_ADDR(raw->flash_offset) == SECTOR_ADDR(fd->raw->flash_offset))
888 continue;
890 D1(printk(KERN_DEBUG "Check potential deletion dirent at %08x\n", ref_offset(raw)));
892 /* This is an obsolete node belonging to the same directory, and it's of the right
893 length. We need to take a closer look...*/
894 ret = jffs2_flash_read(c, ref_offset(raw), rawlen, &retlen, (char *)rd);
895 if (ret) {
896 printk(KERN_WARNING "jffs2_g_c_deletion_dirent(): Read error (%d) reading obsolete node at %08x\n", ret, ref_offset(raw));
897 /* If we can't read it, we don't need to continue to obsolete it. Continue */
898 continue;
900 if (retlen != rawlen) {
901 printk(KERN_WARNING "jffs2_g_c_deletion_dirent(): Short read (%zd not %u) reading header from obsolete node at %08x\n",
902 retlen, rawlen, ref_offset(raw));
903 continue;
906 if (je16_to_cpu(rd->nodetype) != JFFS2_NODETYPE_DIRENT)
907 continue;
909 /* If the name CRC doesn't match, skip */
910 if (je32_to_cpu(rd->name_crc) != name_crc)
911 continue;
913 /* If the name length doesn't match, or it's another deletion dirent, skip */
914 if (rd->nsize != name_len || !je32_to_cpu(rd->ino))
915 continue;
917 /* OK, check the actual name now */
918 if (memcmp(rd->name, fd->name, name_len))
919 continue;
921 /* OK. The name really does match. There really is still an older node on
922 the flash which our deletion dirent obsoletes. So we have to write out
923 a new deletion dirent to replace it */
924 mutex_unlock(&c->erase_free_sem);
926 D1(printk(KERN_DEBUG "Deletion dirent at %08x still obsoletes real dirent \"%s\" at %08x for ino #%u\n",
927 ref_offset(fd->raw), fd->name, ref_offset(raw), je32_to_cpu(rd->ino)));
928 kfree(rd);
930 return jffs2_garbage_collect_dirent(c, jeb, f, fd);
933 mutex_unlock(&c->erase_free_sem);
934 kfree(rd);
937 /* FIXME: If we're deleting a dirent which contains the current mtime and ctime,
938 we should update the metadata node with those times accordingly */
940 /* No need for it any more. Just mark it obsolete and remove it from the list */
941 while (*fdp) {
942 if ((*fdp) == fd) {
943 found = 1;
944 *fdp = fd->next;
945 break;
947 fdp = &(*fdp)->next;
949 if (!found) {
950 printk(KERN_WARNING "Deletion dirent \"%s\" not found in list for ino #%u\n", fd->name, f->inocache->ino);
952 jffs2_mark_node_obsolete(c, fd->raw);
953 jffs2_free_full_dirent(fd);
954 return 0;
957 static int jffs2_garbage_collect_hole(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
958 struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
959 uint32_t start, uint32_t end)
961 struct jffs2_raw_inode ri;
962 struct jffs2_node_frag *frag;
963 struct jffs2_full_dnode *new_fn;
964 uint32_t alloclen, ilen;
965 int ret;
967 D1(printk(KERN_DEBUG "Writing replacement hole node for ino #%u from offset 0x%x to 0x%x\n",
968 f->inocache->ino, start, end));
970 memset(&ri, 0, sizeof(ri));
972 if(fn->frags > 1) {
973 size_t readlen;
974 uint32_t crc;
975 /* It's partially obsoleted by a later write. So we have to
976 write it out again with the _same_ version as before */
977 ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(ri), &readlen, (char *)&ri);
978 if (readlen != sizeof(ri) || ret) {
979 printk(KERN_WARNING "Node read failed in jffs2_garbage_collect_hole. Ret %d, retlen %zd. Data will be lost by writing new hole node\n", ret, readlen);
980 goto fill;
982 if (je16_to_cpu(ri.nodetype) != JFFS2_NODETYPE_INODE) {
983 printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had node type 0x%04x instead of JFFS2_NODETYPE_INODE(0x%04x)\n",
984 ref_offset(fn->raw),
985 je16_to_cpu(ri.nodetype), JFFS2_NODETYPE_INODE);
986 return -EIO;
988 if (je32_to_cpu(ri.totlen) != sizeof(ri)) {
989 printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had totlen 0x%x instead of expected 0x%zx\n",
990 ref_offset(fn->raw),
991 je32_to_cpu(ri.totlen), sizeof(ri));
992 return -EIO;
994 crc = crc32(0, &ri, sizeof(ri)-8);
995 if (crc != je32_to_cpu(ri.node_crc)) {
996 printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had CRC 0x%08x which doesn't match calculated CRC 0x%08x\n",
997 ref_offset(fn->raw),
998 je32_to_cpu(ri.node_crc), crc);
999 /* FIXME: We could possibly deal with this by writing new holes for each frag */
1000 printk(KERN_WARNING "Data in the range 0x%08x to 0x%08x of inode #%u will be lost\n",
1001 start, end, f->inocache->ino);
1002 goto fill;
1004 if (ri.compr != JFFS2_COMPR_ZERO) {
1005 printk(KERN_WARNING "jffs2_garbage_collect_hole: Node 0x%08x wasn't a hole node!\n", ref_offset(fn->raw));
1006 printk(KERN_WARNING "Data in the range 0x%08x to 0x%08x of inode #%u will be lost\n",
1007 start, end, f->inocache->ino);
1008 goto fill;
1010 } else {
1011 fill:
1012 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
1013 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
1014 ri.totlen = cpu_to_je32(sizeof(ri));
1015 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
1017 ri.ino = cpu_to_je32(f->inocache->ino);
1018 ri.version = cpu_to_je32(++f->highest_version);
1019 ri.offset = cpu_to_je32(start);
1020 ri.dsize = cpu_to_je32(end - start);
1021 ri.csize = cpu_to_je32(0);
1022 ri.compr = JFFS2_COMPR_ZERO;
1025 frag = frag_last(&f->fragtree);
1026 if (frag)
1027 /* Fetch the inode length from the fragtree rather then
1028 * from i_size since i_size may have not been updated yet */
1029 ilen = frag->ofs + frag->size;
1030 else
1031 ilen = JFFS2_F_I_SIZE(f);
1033 ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
1034 ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
1035 ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
1036 ri.isize = cpu_to_je32(ilen);
1037 ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
1038 ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
1039 ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
1040 ri.data_crc = cpu_to_je32(0);
1041 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
1043 ret = jffs2_reserve_space_gc(c, sizeof(ri), &alloclen,
1044 JFFS2_SUMMARY_INODE_SIZE);
1045 if (ret) {
1046 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_hole failed: %d\n",
1047 sizeof(ri), ret);
1048 return ret;
1050 new_fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_GC);
1052 if (IS_ERR(new_fn)) {
1053 printk(KERN_WARNING "Error writing new hole node: %ld\n", PTR_ERR(new_fn));
1054 return PTR_ERR(new_fn);
1056 if (je32_to_cpu(ri.version) == f->highest_version) {
1057 jffs2_add_full_dnode_to_inode(c, f, new_fn);
1058 if (f->metadata) {
1059 jffs2_mark_node_obsolete(c, f->metadata->raw);
1060 jffs2_free_full_dnode(f->metadata);
1061 f->metadata = NULL;
1063 return 0;
1067 * We should only get here in the case where the node we are
1068 * replacing had more than one frag, so we kept the same version
1069 * number as before. (Except in case of error -- see 'goto fill;'
1070 * above.)
1072 D1(if(unlikely(fn->frags <= 1)) {
1073 printk(KERN_WARNING "jffs2_garbage_collect_hole: Replacing fn with %d frag(s) but new ver %d != highest_version %d of ino #%d\n",
1074 fn->frags, je32_to_cpu(ri.version), f->highest_version,
1075 je32_to_cpu(ri.ino));
1078 /* This is a partially-overlapped hole node. Mark it REF_NORMAL not REF_PRISTINE */
1079 mark_ref_normal(new_fn->raw);
1081 for (frag = jffs2_lookup_node_frag(&f->fragtree, fn->ofs);
1082 frag; frag = frag_next(frag)) {
1083 if (frag->ofs > fn->size + fn->ofs)
1084 break;
1085 if (frag->node == fn) {
1086 frag->node = new_fn;
1087 new_fn->frags++;
1088 fn->frags--;
1091 if (fn->frags) {
1092 printk(KERN_WARNING "jffs2_garbage_collect_hole: Old node still has frags!\n");
1093 BUG();
1095 if (!new_fn->frags) {
1096 printk(KERN_WARNING "jffs2_garbage_collect_hole: New node has no frags!\n");
1097 BUG();
1100 jffs2_mark_node_obsolete(c, fn->raw);
1101 jffs2_free_full_dnode(fn);
1103 return 0;
1106 static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *orig_jeb,
1107 struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
1108 uint32_t start, uint32_t end)
1110 struct jffs2_full_dnode *new_fn;
1111 struct jffs2_raw_inode ri;
1112 uint32_t alloclen, offset, orig_end, orig_start;
1113 int ret = 0;
1114 unsigned char *comprbuf = NULL, *writebuf;
1115 unsigned long pg;
1116 unsigned char *pg_ptr;
1118 memset(&ri, 0, sizeof(ri));
1120 D1(printk(KERN_DEBUG "Writing replacement dnode for ino #%u from offset 0x%x to 0x%x\n",
1121 f->inocache->ino, start, end));
1123 orig_end = end;
1124 orig_start = start;
1126 if (c->nr_free_blocks + c->nr_erasing_blocks > c->resv_blocks_gcmerge) {
1127 /* Attempt to do some merging. But only expand to cover logically
1128 adjacent frags if the block containing them is already considered
1129 to be dirty. Otherwise we end up with GC just going round in
1130 circles dirtying the nodes it already wrote out, especially
1131 on NAND where we have small eraseblocks and hence a much higher
1132 chance of nodes having to be split to cross boundaries. */
1134 struct jffs2_node_frag *frag;
1135 uint32_t min, max;
1137 min = start & ~(PAGE_CACHE_SIZE-1);
1138 max = min + PAGE_CACHE_SIZE;
1140 frag = jffs2_lookup_node_frag(&f->fragtree, start);
1142 /* BUG_ON(!frag) but that'll happen anyway... */
1144 BUG_ON(frag->ofs != start);
1146 /* First grow down... */
1147 while((frag = frag_prev(frag)) && frag->ofs >= min) {
1149 /* If the previous frag doesn't even reach the beginning, there's
1150 excessive fragmentation. Just merge. */
1151 if (frag->ofs > min) {
1152 D1(printk(KERN_DEBUG "Expanding down to cover partial frag (0x%x-0x%x)\n",
1153 frag->ofs, frag->ofs+frag->size));
1154 start = frag->ofs;
1155 continue;
1157 /* OK. This frag holds the first byte of the page. */
1158 if (!frag->node || !frag->node->raw) {
1159 D1(printk(KERN_DEBUG "First frag in page is hole (0x%x-0x%x). Not expanding down.\n",
1160 frag->ofs, frag->ofs+frag->size));
1161 break;
1162 } else {
1164 /* OK, it's a frag which extends to the beginning of the page. Does it live
1165 in a block which is still considered clean? If so, don't obsolete it.
1166 If not, cover it anyway. */
1168 struct jffs2_raw_node_ref *raw = frag->node->raw;
1169 struct jffs2_eraseblock *jeb;
1171 jeb = &c->blocks[raw->flash_offset / c->sector_size];
1173 if (jeb == c->gcblock) {
1174 D1(printk(KERN_DEBUG "Expanding down to cover frag (0x%x-0x%x) in gcblock at %08x\n",
1175 frag->ofs, frag->ofs+frag->size, ref_offset(raw)));
1176 start = frag->ofs;
1177 break;
1179 if (!ISDIRTY(jeb->dirty_size + jeb->wasted_size)) {
1180 D1(printk(KERN_DEBUG "Not expanding down to cover frag (0x%x-0x%x) in clean block %08x\n",
1181 frag->ofs, frag->ofs+frag->size, jeb->offset));
1182 break;
1185 D1(printk(KERN_DEBUG "Expanding down to cover frag (0x%x-0x%x) in dirty block %08x\n",
1186 frag->ofs, frag->ofs+frag->size, jeb->offset));
1187 start = frag->ofs;
1188 break;
1192 /* ... then up */
1194 /* Find last frag which is actually part of the node we're to GC. */
1195 frag = jffs2_lookup_node_frag(&f->fragtree, end-1);
1197 while((frag = frag_next(frag)) && frag->ofs+frag->size <= max) {
1199 /* If the previous frag doesn't even reach the beginning, there's lots
1200 of fragmentation. Just merge. */
1201 if (frag->ofs+frag->size < max) {
1202 D1(printk(KERN_DEBUG "Expanding up to cover partial frag (0x%x-0x%x)\n",
1203 frag->ofs, frag->ofs+frag->size));
1204 end = frag->ofs + frag->size;
1205 continue;
1208 if (!frag->node || !frag->node->raw) {
1209 D1(printk(KERN_DEBUG "Last frag in page is hole (0x%x-0x%x). Not expanding up.\n",
1210 frag->ofs, frag->ofs+frag->size));
1211 break;
1212 } else {
1214 /* OK, it's a frag which extends to the beginning of the page. Does it live
1215 in a block which is still considered clean? If so, don't obsolete it.
1216 If not, cover it anyway. */
1218 struct jffs2_raw_node_ref *raw = frag->node->raw;
1219 struct jffs2_eraseblock *jeb;
1221 jeb = &c->blocks[raw->flash_offset / c->sector_size];
1223 if (jeb == c->gcblock) {
1224 D1(printk(KERN_DEBUG "Expanding up to cover frag (0x%x-0x%x) in gcblock at %08x\n",
1225 frag->ofs, frag->ofs+frag->size, ref_offset(raw)));
1226 end = frag->ofs + frag->size;
1227 break;
1229 if (!ISDIRTY(jeb->dirty_size + jeb->wasted_size)) {
1230 D1(printk(KERN_DEBUG "Not expanding up to cover frag (0x%x-0x%x) in clean block %08x\n",
1231 frag->ofs, frag->ofs+frag->size, jeb->offset));
1232 break;
1235 D1(printk(KERN_DEBUG "Expanding up to cover frag (0x%x-0x%x) in dirty block %08x\n",
1236 frag->ofs, frag->ofs+frag->size, jeb->offset));
1237 end = frag->ofs + frag->size;
1238 break;
1241 D1(printk(KERN_DEBUG "Expanded dnode to write from (0x%x-0x%x) to (0x%x-0x%x)\n",
1242 orig_start, orig_end, start, end));
1244 D1(BUG_ON(end > frag_last(&f->fragtree)->ofs + frag_last(&f->fragtree)->size));
1245 BUG_ON(end < orig_end);
1246 BUG_ON(start > orig_start);
1249 /* First, use readpage() to read the appropriate page into the page cache */
1250 /* Q: What happens if we actually try to GC the _same_ page for which commit_write()
1251 * triggered garbage collection in the first place?
1252 * A: I _think_ it's OK. read_cache_page shouldn't deadlock, we'll write out the
1253 * page OK. We'll actually write it out again in commit_write, which is a little
1254 * suboptimal, but at least we're correct.
1256 pg_ptr = jffs2_gc_fetch_page(c, f, start, &pg);
1258 if (IS_ERR(pg_ptr)) {
1259 printk(KERN_WARNING "read_cache_page() returned error: %ld\n", PTR_ERR(pg_ptr));
1260 return PTR_ERR(pg_ptr);
1263 offset = start;
1264 while(offset < orig_end) {
1265 uint32_t datalen;
1266 uint32_t cdatalen;
1267 uint16_t comprtype = JFFS2_COMPR_NONE;
1269 ret = jffs2_reserve_space_gc(c, sizeof(ri) + JFFS2_MIN_DATA_LEN,
1270 &alloclen, JFFS2_SUMMARY_INODE_SIZE);
1272 if (ret) {
1273 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dnode failed: %d\n",
1274 sizeof(ri)+ JFFS2_MIN_DATA_LEN, ret);
1275 break;
1277 cdatalen = min_t(uint32_t, alloclen - sizeof(ri), end - offset);
1278 datalen = end - offset;
1280 writebuf = pg_ptr + (offset & (PAGE_CACHE_SIZE -1));
1282 comprtype = jffs2_compress(c, f, writebuf, &comprbuf, &datalen, &cdatalen);
1284 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
1285 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
1286 ri.totlen = cpu_to_je32(sizeof(ri) + cdatalen);
1287 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
1289 ri.ino = cpu_to_je32(f->inocache->ino);
1290 ri.version = cpu_to_je32(++f->highest_version);
1291 ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
1292 ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
1293 ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
1294 ri.isize = cpu_to_je32(JFFS2_F_I_SIZE(f));
1295 ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
1296 ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
1297 ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
1298 ri.offset = cpu_to_je32(offset);
1299 ri.csize = cpu_to_je32(cdatalen);
1300 ri.dsize = cpu_to_je32(datalen);
1301 ri.compr = comprtype & 0xff;
1302 ri.usercompr = (comprtype >> 8) & 0xff;
1303 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
1304 ri.data_crc = cpu_to_je32(crc32(0, comprbuf, cdatalen));
1306 new_fn = jffs2_write_dnode(c, f, &ri, comprbuf, cdatalen, ALLOC_GC);
1308 jffs2_free_comprbuf(comprbuf, writebuf);
1310 if (IS_ERR(new_fn)) {
1311 printk(KERN_WARNING "Error writing new dnode: %ld\n", PTR_ERR(new_fn));
1312 ret = PTR_ERR(new_fn);
1313 break;
1315 ret = jffs2_add_full_dnode_to_inode(c, f, new_fn);
1316 offset += datalen;
1317 if (f->metadata) {
1318 jffs2_mark_node_obsolete(c, f->metadata->raw);
1319 jffs2_free_full_dnode(f->metadata);
1320 f->metadata = NULL;
1324 jffs2_gc_release_page(c, pg_ptr, &pg);
1325 return ret;