fs/jffs2.org/gc.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@redhat.com>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  * $Id: gc.c,v 1.136 2004/05/27 19:06:09 gleixner Exp $
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/slab.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/crc32.h>
  19 #include <linux/compiler.h>
  20 #include <linux/stat.h>
  21 #include "nodelist.h"
  22 #include "compr.h"
  23
  24 static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
  25                                           struct jffs2_inode_cache *ic,
  26                                           struct jffs2_raw_node_ref *raw);
  27 static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  28                                         struct jffs2_inode_info *f, struct jffs2_full_dnode *fd);
  29 static int jffs2_garbage_collect_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  30                                         struct jffs2_inode_info *f, struct jffs2_full_dirent *fd);
  31 static int jffs2_garbage_collect_deletion_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  32                                         struct jffs2_inode_info *f, struct jffs2_full_dirent *fd);
  33 static int jffs2_garbage_collect_hole(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  34                                       struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
  35                                       uint32_t start, uint32_t end);
  36 static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  37                                        struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
  38                                        uint32_t start, uint32_t end);
  39 static int jffs2_garbage_collect_live(struct jffs2_sb_info *c,  struct jffs2_eraseblock *jeb,
  40                                struct jffs2_raw_node_ref *raw, struct jffs2_inode_info *f);
  41
  42 /* Called with erase_completion_lock held */
  43 static struct jffs2_eraseblock *jffs2_find_gc_block(struct jffs2_sb_info *c)
  44 {
  45         struct jffs2_eraseblock *ret;
  46         struct list_head *nextlist = NULL;
  47         int n = jiffies % 128;
  48
  49         /* Pick an eraseblock to garbage collect next. This is where we'll
  50            put the clever wear-levelling algorithms. Eventually.  */
  51         /* We possibly want to favour the dirtier blocks more when the
  52            number of free blocks is low. */
  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"));
  73
  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"));
  80
  81                 nextlist = &c->erasable_list;
  82         } else {
  83                 /* Eep. All were empty */
  84                 D1(printk(KERN_NOTICE "jffs2: No clean, dirty _or_ erasable blocks to GC from! Where are they all?\n"));
  85                 return NULL;
  86         }
  87
  88         ret = list_entry(nextlist->next, struct jffs2_eraseblock, list);
  89         list_del(&ret->list);
  90         c->gcblock = ret;
  91         ret->gc_node = ret->first_node;
  92         if (!ret->gc_node) {
  93                 printk(KERN_WARNING "Eep. ret->gc_node for block at 0x%08x is NULL\n", ret->offset);
  94                 BUG();
  95         }
  96
  97         /* Have we accidentally picked a clean block with wasted space ? */
  98         if (ret->wasted_size) {
  99                 D1(printk(KERN_DEBUG "Converting wasted_size %08x to dirty_size\n", ret->wasted_size));
 100                 ret->dirty_size += ret->wasted_size;
 101                 c->wasted_size -= ret->wasted_size;
 102                 c->dirty_size += ret->wasted_size;
 103                 ret->wasted_size = 0;
 104         }
 105
 106         D1(jffs2_dump_block_lists(c));
 107         return ret;
 108 }
 109
 110 /* jffs2_garbage_collect_pass
 111  * Make a single attempt to progress GC. Move one node, and possibly
 112  * start erasing one eraseblock.
 113  */
 114 int jffs2_garbage_collect_pass(struct jffs2_sb_info *c)
 115 {
 116         struct jffs2_inode_info *f;
 117         struct jffs2_inode_cache *ic;
 118         struct jffs2_eraseblock *jeb;
 119         struct jffs2_raw_node_ref *raw;
 120         int ret = 0, inum, nlink;
 121
 122         if (down_interruptible(&c->alloc_sem))
 123                 return -EINTR;
 124
 125         for (;;) {
 126                 spin_lock(&c->erase_completion_lock);
 127                 if (!c->unchecked_size)
 128                         break;
 129
 130                 /* We can't start doing GC yet. We haven't finished checking
 131                    the node CRCs etc. Do it now. */
 132
 133                 /* checked_ino is protected by the alloc_sem */
 134                 if (c->checked_ino > c->highest_ino) {
 135                         printk(KERN_CRIT "Checked all inodes but still 0x%x bytes of unchecked space?\n",
 136                                c->unchecked_size);
 137                         D1(jffs2_dump_block_lists(c));
 138                         spin_unlock(&c->erase_completion_lock);
 139                         BUG();
 140                 }
 141
 142                 spin_unlock(&c->erase_completion_lock);
 143
 144                 spin_lock(&c->inocache_lock);
 145
 146                 ic = jffs2_get_ino_cache(c, c->checked_ino++);
 147
 148                 if (!ic) {
 149                         spin_unlock(&c->inocache_lock);
 150                         continue;
 151                 }
 152
 153                 if (!ic->nlink) {
 154                         D1(printk(KERN_DEBUG "Skipping check of ino #%d with nlink zero\n",
 155                                   ic->ino));
 156                         spin_unlock(&c->inocache_lock);
 157                         continue;
 158                 }
 159                 switch(ic->state) {
 160                 case INO_STATE_CHECKEDABSENT:
 161                 case INO_STATE_PRESENT:
 162                         D1(printk(KERN_DEBUG "Skipping ino #%u already checked\n", ic->ino));
 163                         spin_unlock(&c->inocache_lock);
 164                         continue;
 165
 166                 case INO_STATE_GC:
 167                 case INO_STATE_CHECKING:
 168                         printk(KERN_WARNING "Inode #%u is in state %d during CRC check phase!\n", ic->ino, ic->state);
 169                         spin_unlock(&c->inocache_lock);
 170                         BUG();
 171
 172                 case INO_STATE_READING:
 173                         /* We need to wait for it to finish, lest we move on
 174                            and trigger the BUG() above while we haven't yet
 175                            finished checking all its nodes */
 176                         D1(printk(KERN_DEBUG "Waiting for ino #%u to finish reading\n", ic->ino));
 177                         up(&c->alloc_sem);
 178                         sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
 179                         return 0;
 180
 181                 default:
 182                         BUG();
 183
 184                 case INO_STATE_UNCHECKED:
 185                         ;
 186                 }
 187                 ic->state = INO_STATE_CHECKING;
 188                 spin_unlock(&c->inocache_lock);
 189
 190                 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() triggering inode scan of ino#%u\n", ic->ino));
 191
 192                 ret = jffs2_do_crccheck_inode(c, ic);
 193                 if (ret)
 194                         printk(KERN_WARNING "Returned error for crccheck of ino #%u. Expect badness...\n", ic->ino);
 195
 196                 jffs2_set_inocache_state(c, ic, INO_STATE_CHECKEDABSENT);
 197                 up(&c->alloc_sem);
 198                 return ret;
 199         }
 200
 201         /* First, work out which block we're garbage-collecting */
 202         jeb = c->gcblock;
 203
 204         if (!jeb)
 205                 jeb = jffs2_find_gc_block(c);
 206
 207         if (!jeb) {
 208                 D1 (printk(KERN_NOTICE "jffs2: Couldn't find erase block to garbage collect!\n"));
 209                 spin_unlock(&c->erase_completion_lock);
 210                 up(&c->alloc_sem);
 211                 return -EIO;
 212         }
 213
 214         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));
 215         D1(if (c->nextblock)
 216            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));
 217
 218         if (!jeb->used_size) {
 219                 up(&c->alloc_sem);
 220                 goto eraseit;
 221         }
 222
 223         raw = jeb->gc_node;
 224
 225         while(ref_obsolete(raw)) {
 226                 D1(printk(KERN_DEBUG "Node at 0x%08x is obsolete... skipping\n", ref_offset(raw)));
 227                 raw = raw->next_phys;
 228                 if (unlikely(!raw)) {
 229                         printk(KERN_WARNING "eep. End of raw list while still supposedly nodes to GC\n");
 230                         printk(KERN_WARNING "erase block at 0x%08x. free_size 0x%08x, dirty_size 0x%08x, used_size 0x%08x\n",
 231                                jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size);
 232                         jeb->gc_node = raw;
 233                         spin_unlock(&c->erase_completion_lock);
 234                         up(&c->alloc_sem);
 235                         BUG();
 236                 }
 237         }
 238         jeb->gc_node = raw;
 239
 240         D1(printk(KERN_DEBUG "Going to garbage collect node at 0x%08x\n", ref_offset(raw)));
 241
 242         if (!raw->next_in_ino) {
 243                 /* Inode-less node. Clean marker, snapshot or something like that */
 244                 /* FIXME: If it's something that needs to be copied, including something
 245                    we don't grok that has JFFS2_NODETYPE_RWCOMPAT_COPY, we should do so */
 246                 spin_unlock(&c->erase_completion_lock);
 247                 jffs2_mark_node_obsolete(c, raw);
 248                 up(&c->alloc_sem);
 249                 goto eraseit_lock;
 250         }
 251
 252         ic = jffs2_raw_ref_to_ic(raw);
 253
 254         /* We need to hold the inocache. Either the erase_completion_lock or
 255            the inocache_lock are sufficient; we trade down since the inocache_lock
 256            causes less contention. */
 257         spin_lock(&c->inocache_lock);
 258
 259         spin_unlock(&c->erase_completion_lock);
 260
 261         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));
 262
 263         /* Three possibilities:
 264            1. Inode is already in-core. We must iget it and do proper
 265               updating to its fragtree, etc.
 266            2. Inode is not in-core, node is REF_PRISTINE. We lock the
 267               inocache to prevent a read_inode(), copy the node intact.
 268            3. Inode is not in-core, node is not pristine. We must iget()
 269               and take the slow path.
 270         */
 271
 272         switch(ic->state) {
 273         case INO_STATE_CHECKEDABSENT:
 274                 /* It's been checked, but it's not currently in-core.
 275                    We can just copy any pristine nodes, but have
 276                    to prevent anyone else from doing read_inode() while
 277                    we're at it, so we set the state accordingly */
 278                 if (ref_flags(raw) == REF_PRISTINE)
 279                         ic->state = INO_STATE_GC;
 280                 else {
 281                         D1(printk(KERN_DEBUG "Ino #%u is absent but node not REF_PRISTINE. Reading.\n",
 282                                   ic->ino));
 283                 }
 284                 break;
 285
 286         case INO_STATE_PRESENT:
 287                 /* It's in-core. GC must iget() it. */
 288                 break;
 289
 290         case INO_STATE_UNCHECKED:
 291         case INO_STATE_CHECKING:
 292         case INO_STATE_GC:
 293                 /* Should never happen. We should have finished checking
 294                    by the time we actually start doing any GC, and since
 295                    we're holding the alloc_sem, no other garbage collection
 296                    can happen.
 297                 */
 298                 printk(KERN_CRIT "Inode #%u already in state %d in jffs2_garbage_collect_pass()!\n",
 299                        ic->ino, ic->state);
 300                 up(&c->alloc_sem);
 301                 spin_unlock(&c->inocache_lock);
 302                 BUG();
 303
 304         case INO_STATE_READING:
 305                 /* Someone's currently trying to read it. We must wait for
 306                    them to finish and then go through the full iget() route
 307                    to do the GC. However, sometimes read_inode() needs to get
 308                    the alloc_sem() (for marking nodes invalid) so we must
 309                    drop the alloc_sem before sleeping. */
 310
 311                 up(&c->alloc_sem);
 312                 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() waiting for ino #%u in state %d\n",
 313                           ic->ino, ic->state));
 314                 sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
 315                 /* And because we dropped the alloc_sem we must start again from the
 316                    beginning. Ponder chance of livelock here -- we're returning success
 317                    without actually making any progress.
 318
 319                    Q: What are the chances that the inode is back in INO_STATE_READING
 320                    again by the time we next enter this function? And that this happens
 321                    enough times to cause a real delay?
 322
 323                    A: Small enough that I don't care :)
 324                 */
 325                 return 0;
 326         }
 327
 328         /* OK. Now if the inode is in state INO_STATE_GC, we are going to copy the
 329            node intact, and we don't have to muck about with the fragtree etc.
 330            because we know it's not in-core. If it _was_ in-core, we go through
 331            all the iget() crap anyway */
 332
 333         if (ic->state == INO_STATE_GC) {
 334                 spin_unlock(&c->inocache_lock);
 335
 336                 ret = jffs2_garbage_collect_pristine(c, ic, raw);
 337
 338                 spin_lock(&c->inocache_lock);
 339                 ic->state = INO_STATE_CHECKEDABSENT;
 340                 wake_up(&c->inocache_wq);
 341
 342                 if (ret != -EBADFD) {
 343                         spin_unlock(&c->inocache_lock);
 344                         goto release_sem;
 345                 }
 346
 347                 /* Fall through if it wanted us to, with inocache_lock held */
 348         }
 349
 350         /* Prevent the fairly unlikely race where the gcblock is
 351            entirely obsoleted by the final close of a file which had
 352            the only valid nodes in the block, followed by erasure,
 353            followed by freeing of the ic because the erased block(s)
 354            held _all_ the nodes of that inode.... never been seen but
 355            it's vaguely possible. */
 356
 357         inum = ic->ino;
 358         nlink = ic->nlink;
 359         spin_unlock(&c->inocache_lock);
 360
 361         f = jffs2_gc_fetch_inode(c, inum, nlink);
 362         if (IS_ERR(f))
 363                 return PTR_ERR(f);
 364         if (!f)
 365                 return 0;
 366
 367         ret = jffs2_garbage_collect_live(c, jeb, raw, f);
 368
 369         jffs2_gc_release_inode(c, f);
 370
 371  release_sem:
 372         up(&c->alloc_sem);
 373
 374  eraseit_lock:
 375         /* If we've finished this block, start it erasing */
 376         spin_lock(&c->erase_completion_lock);
 377
 378  eraseit:
 379         if (c->gcblock && !c->gcblock->used_size) {
 380                 D1(printk(KERN_DEBUG "Block at 0x%08x completely obsoleted by GC. Moving to erase_pending_list\n", c->gcblock->offset));
 381                 /* We're GC'ing an empty block? */
 382                 list_add_tail(&c->gcblock->list, &c->erase_pending_list);
 383                 c->gcblock = NULL;
 384                 c->nr_erasing_blocks++;
 385                 jffs2_erase_pending_trigger(c);
 386         }
 387         spin_unlock(&c->erase_completion_lock);
 388
 389         return ret;
 390 }
 391
 392 static int jffs2_garbage_collect_live(struct jffs2_sb_info *c,  struct jffs2_eraseblock *jeb,
 393                                       struct jffs2_raw_node_ref *raw, struct jffs2_inode_info *f)
 394 {
 395         struct jffs2_node_frag *frag;
 396         struct jffs2_full_dnode *fn = NULL;
 397         struct jffs2_full_dirent *fd;
 398         uint32_t start = 0, end = 0, nrfrags = 0;
 399         int ret = 0;
 400
 401         down(&f->sem);
 402
 403         /* Now we have the lock for this inode. Check that it's still the one at the head
 404            of the list. */
 405
 406         spin_lock(&c->erase_completion_lock);
 407
 408         if (c->gcblock != jeb) {
 409                 spin_unlock(&c->erase_completion_lock);
 410                 D1(printk(KERN_DEBUG "GC block is no longer gcblock. Restart\n"));
 411                 goto upnout;
 412         }
 413         if (ref_obsolete(raw)) {
 414                 spin_unlock(&c->erase_completion_lock);
 415                 D1(printk(KERN_DEBUG "node to be GC'd was obsoleted in the meantime.\n"));
 416                 /* They'll call again */
 417                 goto upnout;
 418         }
 419         spin_unlock(&c->erase_completion_lock);
 420
 421         /* OK. Looks safe. And nobody can get us now because we have the semaphore. Move the block */
 422         if (f->metadata && f->metadata->raw == raw) {
 423                 fn = f->metadata;
 424                 ret = jffs2_garbage_collect_metadata(c, jeb, f, fn);
 425                 goto upnout;
 426         }
 427
 428         /* FIXME. Read node and do lookup? */
 429         for (frag = frag_first(&f->fragtree); frag; frag = frag_next(frag)) {
 430                 if (frag->node && frag->node->raw == raw) {
 431                         fn = frag->node;
 432                         end = frag->ofs + frag->size;
 433                         if (!nrfrags++)
 434                                 start = frag->ofs;
 435                         if (nrfrags == frag->node->frags)
 436                                 break; /* We've found them all */
 437                 }
 438         }
 439         if (fn) {
 440                 if (ref_flags(raw) == REF_PRISTINE) {
 441                         ret = jffs2_garbage_collect_pristine(c, f->inocache, raw);
 442                         if (!ret) {
 443                                 /* Urgh. Return it sensibly. */
 444                                 frag->node->raw = f->inocache->nodes;
 445                         }
 446                         if (ret != -EBADFD)
 447                                 goto upnout;
 448                 }
 449                 /* We found a datanode. Do the GC */
 450                 if((start >> PAGE_CACHE_SHIFT) < ((end-1) >> PAGE_CACHE_SHIFT)) {
 451                         /* It crosses a page boundary. Therefore, it must be a hole. */
 452                         ret = jffs2_garbage_collect_hole(c, jeb, f, fn, start, end);
 453                 } else {
 454                         /* It could still be a hole. But we GC the page this way anyway */
 455                         ret = jffs2_garbage_collect_dnode(c, jeb, f, fn, start, end);
 456                 }
 457                 goto upnout;
 458         }
 459
 460         /* Wasn't a dnode. Try dirent */
 461         for (fd = f->dents; fd; fd=fd->next) {
 462                 if (fd->raw == raw)
 463                         break;
 464         }
 465
 466         if (fd && fd->ino) {
 467                 ret = jffs2_garbage_collect_dirent(c, jeb, f, fd);
 468         } else if (fd) {
 469                 ret = jffs2_garbage_collect_deletion_dirent(c, jeb, f, fd);
 470         } else {
 471                 printk(KERN_WARNING "Raw node at 0x%08x wasn't in node lists for ino #%u\n",
 472                        ref_offset(raw), f->inocache->ino);
 473                 if (ref_obsolete(raw)) {
 474                         printk(KERN_WARNING "But it's obsolete so we don't mind too much\n");
 475                 } else {
 476                         ret = -EIO;
 477                 }
 478         }
 479  upnout:
 480         up(&f->sem);
 481
 482         return ret;
 483 }
 484
 485 static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c,
 486                                           struct jffs2_inode_cache *ic,
 487                                           struct jffs2_raw_node_ref *raw)
 488 {
 489         union jffs2_node_union *node;
 490         struct jffs2_raw_node_ref *nraw;
 491         size_t retlen;
 492         int ret;
 493         uint32_t phys_ofs, alloclen;
 494         uint32_t crc, rawlen;
 495         int retried = 0;
 496
 497         D1(printk(KERN_DEBUG "Going to GC REF_PRISTINE node at 0x%08x\n", ref_offset(raw)));
 498
 499         rawlen = ref_totlen(c, c->gcblock, raw);
 500
 501         /* Ask for a small amount of space (or the totlen if smaller) because we
 502            don't want to force wastage of the end of a block if splitting would
 503            work. */
 504         ret = jffs2_reserve_space_gc(c, min_t(uint32_t, sizeof(struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN,
 505                                               rawlen), &phys_ofs, &alloclen);
 506         if (ret)
 507                 return ret;
 508
 509         if (alloclen < rawlen) {
 510                 /* Doesn't fit untouched. We'll go the old route and split it */
 511                 return -EBADFD;
 512         }
 513
 514         node = kmalloc(rawlen, GFP_KERNEL);
 515         if (!node)
 516                return -ENOMEM;
 517
 518         ret = jffs2_flash_read(c, ref_offset(raw), rawlen, &retlen, (char *)node);
 519         if (!ret && retlen != rawlen)
 520                 ret = -EIO;
 521         if (ret)
 522                 goto out_node;
 523
 524         crc = crc32(0, node, sizeof(struct jffs2_unknown_node)-4);
 525         if (je32_to_cpu(node->u.hdr_crc) != crc) {
 526 #if 0   // mask by Victor Yu. 04-07-2007
 527                 printk(KERN_WARNING "Header CRC failed on REF_PRISTINE node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 528                        ref_offset(raw), je32_to_cpu(node->u.hdr_crc), crc);
 529 #endif
 530                 goto bail;
 531         }
 532
 533         switch(je16_to_cpu(node->u.nodetype)) {
 534         case JFFS2_NODETYPE_INODE:
 535                 crc = crc32(0, node, sizeof(node->i)-8);
 536                 if (je32_to_cpu(node->i.node_crc) != crc) {
 537 #if 0   // mask by Victor Yu. 04-07-2007
 538                         printk(KERN_WARNING "Node CRC failed on REF_PRISTINE data node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 539                                ref_offset(raw), je32_to_cpu(node->i.node_crc), crc);
 540 #endif
 541                         goto bail;
 542                 }
 543
 544                 if (je32_to_cpu(node->i.dsize)) {
 545                         crc = crc32(0, node->i.data, je32_to_cpu(node->i.csize));
 546                         if (je32_to_cpu(node->i.data_crc) != crc) {
 547 #if 0   // mask by Victor Yu. 04-07-2007
 548                                 printk(KERN_WARNING "Data CRC failed on REF_PRISTINE data node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 549                                        ref_offset(raw), je32_to_cpu(node->i.data_crc), crc);
 550 #endif
 551                                 goto bail;
 552                         }
 553                 }
 554                 break;
 555
 556         case JFFS2_NODETYPE_DIRENT:
 557                 crc = crc32(0, node, sizeof(node->d)-8);
 558                 if (je32_to_cpu(node->d.node_crc) != crc) {
 559 #if 0   // mask by Victor Yu. 04-07-2007
 560                         printk(KERN_WARNING "Node CRC failed on REF_PRISTINE dirent node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 561                                ref_offset(raw), je32_to_cpu(node->d.node_crc), crc);
 562 #endif
 563                         goto bail;
 564                 }
 565
 566                 if (node->d.nsize) {
 567                         crc = crc32(0, node->d.name, node->d.nsize);
 568                         if (je32_to_cpu(node->d.name_crc) != crc) {
 569 #if 0   // mask by Victor Yu. 04-07-2007
 570                                 printk(KERN_WARNING "Name CRC failed on REF_PRISTINE dirent ode at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 571                                        ref_offset(raw), je32_to_cpu(node->d.name_crc), crc);
 572 #endif
 573                                 goto bail;
 574                         }
 575                 }
 576                 break;
 577         default:
 578                 printk(KERN_WARNING "Unknown node type for REF_PRISTINE node at 0x%08x: 0x%04x\n",
 579                        ref_offset(raw), je16_to_cpu(node->u.nodetype));
 580                 goto bail;
 581         }
 582
 583         nraw = jffs2_alloc_raw_node_ref();
 584         if (!nraw) {
 585                 ret = -ENOMEM;
 586                 goto out_node;
 587         }
 588
 589         /* OK, all the CRCs are good; this node can just be copied as-is. */
 590  retry:
 591         nraw->flash_offset = phys_ofs;
 592         nraw->__totlen = rawlen;
 593         nraw->next_phys = NULL;
 594
 595         ret = jffs2_flash_write(c, phys_ofs, rawlen, &retlen, (char *)node);
 596
 597         if (ret || (retlen != rawlen)) {
 598                 printk(KERN_NOTICE "Write of %d bytes at 0x%08x failed. returned %d, retlen %zd\n",
 599                        rawlen, phys_ofs, ret, retlen);
 600                 if (retlen) {
 601                         /* Doesn't belong to any inode */
 602                         nraw->next_in_ino = NULL;
 603
 604                         nraw->flash_offset |= REF_OBSOLETE;
 605                         jffs2_add_physical_node_ref(c, nraw);
 606                         jffs2_mark_node_obsolete(c, nraw);
 607                 } else {
 608                         printk(KERN_NOTICE "Not marking the space at 0x%08x as dirty because the flash driver returned retlen zero\n", nraw->flash_offset);
 609                         jffs2_free_raw_node_ref(nraw);
 610                 }
 611                 if (!retried && (nraw == jffs2_alloc_raw_node_ref())) {
 612                         /* Try to reallocate space and retry */
 613                         uint32_t dummy;
 614                         struct jffs2_eraseblock *jeb = &c->blocks[phys_ofs / c->sector_size];
 615
 616                         retried = 1;
 617
 618                         D1(printk(KERN_DEBUG "Retrying failed write of REF_PRISTINE node.\n"));
 619
 620                         ACCT_SANITY_CHECK(c,jeb);
 621                         D1(ACCT_PARANOIA_CHECK(jeb));
 622
 623                         ret = jffs2_reserve_space_gc(c, rawlen, &phys_ofs, &dummy);
 624
 625                         if (!ret) {
 626                                 D1(printk(KERN_DEBUG "Allocated space at 0x%08x to retry failed write.\n", phys_ofs));
 627
 628                                 ACCT_SANITY_CHECK(c,jeb);
 629                                 D1(ACCT_PARANOIA_CHECK(jeb));
 630
 631                                 goto retry;
 632                         }
 633                         D1(printk(KERN_DEBUG "Failed to allocate space to retry failed write: %d!\n", ret));
 634                         jffs2_free_raw_node_ref(nraw);
 635                 }
 636
 637                 if (!ret)
 638                         ret = -EIO;
 639                 goto out_node;
 640         }
 641         nraw->flash_offset |= REF_PRISTINE;
 642         jffs2_add_physical_node_ref(c, nraw);
 643
 644         /* Link into per-inode list. This is safe because of the ic
 645            state being INO_STATE_GC. Note that if we're doing this
 646            for an inode which is in-code, the 'nraw' pointer is then
 647            going to be fetched from ic->nodes by our caller. */
 648         nraw->next_in_ino = ic->nodes;
 649         ic->nodes = nraw;
 650
 651         jffs2_mark_node_obsolete(c, raw);
 652         D1(printk(KERN_DEBUG "WHEEE! GC REF_PRISTINE node at 0x%08x succeeded\n", ref_offset(raw)));
 653
 654  out_node:
 655         kfree(node);
 656         return ret;
 657  bail:
 658         ret = -EBADFD;
 659         goto out_node;
 660 }
 661
 662 static int jffs2_garbage_collect_metadata(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 663                                         struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 664 {
 665         struct jffs2_full_dnode *new_fn;
 666         struct jffs2_raw_inode ri;
 667         jint16_t dev;
 668         char *mdata = NULL, mdatalen = 0;
 669         uint32_t alloclen, phys_ofs;
 670         int ret;
 671
 672         if (S_ISBLK(JFFS2_F_I_MODE(f)) ||
 673             S_ISCHR(JFFS2_F_I_MODE(f)) ) {
 674                 /* For these, we don't actually need to read the old node */
 675                 /* FIXME: for minor or major > 255. */
 676                 dev = cpu_to_je16(((JFFS2_F_I_RDEV_MAJ(f) << 8) |
 677                         JFFS2_F_I_RDEV_MIN(f)));
 678                 mdata = (char *)&dev;
 679                 mdatalen = sizeof(dev);
 680                 D1(printk(KERN_DEBUG "jffs2_garbage_collect_metadata(): Writing %d bytes of kdev_t\n", mdatalen));
 681         } else if (S_ISLNK(JFFS2_F_I_MODE(f))) {
 682                 mdatalen = fn->size;
 683                 mdata = kmalloc(fn->size, GFP_KERNEL);
 684                 if (!mdata) {
 685                         printk(KERN_WARNING "kmalloc of mdata failed in jffs2_garbage_collect_metadata()\n");
 686                         return -ENOMEM;
 687                 }
 688                 ret = jffs2_read_dnode(c, f, fn, mdata, 0, mdatalen);
 689                 if (ret) {
 690                         printk(KERN_WARNING "read of old metadata failed in jffs2_garbage_collect_metadata(): %d\n", ret);
 691                         kfree(mdata);
 692                         return ret;
 693                 }
 694                 D1(printk(KERN_DEBUG "jffs2_garbage_collect_metadata(): Writing %d bites of symlink target\n", mdatalen));
 695
 696         }
 697
 698         ret = jffs2_reserve_space_gc(c, sizeof(ri) + mdatalen, &phys_ofs, &alloclen);
 699         if (ret) {
 700                 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_metadata failed: %d\n",
 701                        sizeof(ri)+ mdatalen, ret);
 702                 goto out;
 703         }
 704
 705         memset(&ri, 0, sizeof(ri));
 706         ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 707         ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
 708         ri.totlen = cpu_to_je32(sizeof(ri) + mdatalen);
 709         ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
 710
 711         ri.ino = cpu_to_je32(f->inocache->ino);
 712         ri.version = cpu_to_je32(++f->highest_version);
 713         ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
 714         ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
 715         ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
 716         ri.isize = cpu_to_je32(JFFS2_F_I_SIZE(f));
 717         ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
 718         ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
 719         ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
 720         ri.offset = cpu_to_je32(0);
 721         ri.csize = cpu_to_je32(mdatalen);
 722         ri.dsize = cpu_to_je32(mdatalen);
 723         ri.compr = JFFS2_COMPR_NONE;
 724         ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
 725         ri.data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
 726
 727         new_fn = jffs2_write_dnode(c, f, &ri, mdata, mdatalen, phys_ofs, ALLOC_GC);
 728
 729         if (IS_ERR(new_fn)) {
 730                 printk(KERN_WARNING "Error writing new dnode: %ld\n", PTR_ERR(new_fn));
 731                 ret = PTR_ERR(new_fn);
 732                 goto out;
 733         }
 734         jffs2_mark_node_obsolete(c, fn->raw);
 735         jffs2_free_full_dnode(fn);
 736         f->metadata = new_fn;
 737  out:
 738         if (S_ISLNK(JFFS2_F_I_MODE(f)))
 739                 kfree(mdata);
 740         return ret;
 741 }
 742
 743 static int jffs2_garbage_collect_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 744                                         struct jffs2_inode_info *f, struct jffs2_full_dirent *fd)
 745 {
 746         struct jffs2_full_dirent *new_fd;
 747         struct jffs2_raw_dirent rd;
 748         uint32_t alloclen, phys_ofs;
 749         int ret;
 750
 751         rd.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 752         rd.nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 753         rd.nsize = strlen(fd->name);
 754         rd.totlen = cpu_to_je32(sizeof(rd) + rd.nsize);
 755         rd.hdr_crc = cpu_to_je32(crc32(0, &rd, sizeof(struct jffs2_unknown_node)-4));
 756
 757         rd.pino = cpu_to_je32(f->inocache->ino);
 758         rd.version = cpu_to_je32(++f->highest_version);
 759         rd.ino = cpu_to_je32(fd->ino);
 760         rd.mctime = cpu_to_je32(max(JFFS2_F_I_MTIME(f), JFFS2_F_I_CTIME(f)));
 761         rd.type = fd->type;
 762         rd.node_crc = cpu_to_je32(crc32(0, &rd, sizeof(rd)-8));
 763         rd.name_crc = cpu_to_je32(crc32(0, fd->name, rd.nsize));
 764
 765         ret = jffs2_reserve_space_gc(c, sizeof(rd)+rd.nsize, &phys_ofs, &alloclen);
 766         if (ret) {
 767                 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dirent failed: %d\n",
 768                        sizeof(rd)+rd.nsize, ret);
 769                 return ret;
 770         }
 771         new_fd = jffs2_write_dirent(c, f, &rd, fd->name, rd.nsize, phys_ofs, ALLOC_GC);
 772
 773         if (IS_ERR(new_fd)) {
 774                 printk(KERN_WARNING "jffs2_write_dirent in garbage_collect_dirent failed: %ld\n", PTR_ERR(new_fd));
 775                 return PTR_ERR(new_fd);
 776         }
 777         jffs2_add_fd_to_list(c, new_fd, &f->dents);
 778         return 0;
 779 }
 780
 781 static int jffs2_garbage_collect_deletion_dirent(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 782                                         struct jffs2_inode_info *f, struct jffs2_full_dirent *fd)
 783 {
 784         struct jffs2_full_dirent **fdp = &f->dents;
 785         int found = 0;
 786
 787         /* On a medium where we can't actually mark nodes obsolete
 788            pernamently, such as NAND flash, we need to work out
 789            whether this deletion dirent is still needed to actively
 790            delete a 'real' dirent with the same name that's still
 791            somewhere else on the flash. */
 792         if (!jffs2_can_mark_obsolete(c)) {
 793                 struct jffs2_raw_dirent *rd;
 794                 struct jffs2_raw_node_ref *raw;
 795                 int ret;
 796                 size_t retlen;
 797                 int name_len = strlen(fd->name);
 798                 uint32_t name_crc = crc32(0, fd->name, name_len);
 799                 uint32_t rawlen = ref_totlen(c, jeb, fd->raw);
 800
 801                 rd = kmalloc(rawlen, GFP_KERNEL);
 802                 if (!rd)
 803                         return -ENOMEM;
 804
 805                 /* Prevent the erase code from nicking the obsolete node refs while
 806                    we're looking at them. I really don't like this extra lock but
 807                    can't see any alternative. Suggestions on a postcard to... */
 808                 down(&c->erase_free_sem);
 809
 810                 for (raw = f->inocache->nodes; raw != (void *)f->inocache; raw = raw->next_in_ino) {
 811
 812                         /* We only care about obsolete ones */
 813                         if (!(ref_obsolete(raw)))
 814                                 continue;
 815
 816                         /* Any dirent with the same name is going to have the same length... */
 817                         if (ref_totlen(c, NULL, raw) != rawlen)
 818                                 continue;
 819
 820                         /* Doesn't matter if there's one in the same erase block. We're going to
 821                            delete it too at the same time. */
 822                         if ((raw->flash_offset & ~(c->sector_size-1)) ==
 823                             (fd->raw->flash_offset & ~(c->sector_size-1)))
 824                                 continue;
 825
 826                         D1(printk(KERN_DEBUG "Check potential deletion dirent at %08x\n", ref_offset(raw)));
 827
 828                         /* This is an obsolete node belonging to the same directory, and it's of the right
 829                            length. We need to take a closer look...*/
 830                         ret = jffs2_flash_read(c, ref_offset(raw), rawlen, &retlen, (char *)rd);
 831                         if (ret) {
 832                                 printk(KERN_WARNING "jffs2_g_c_deletion_dirent(): Read error (%d) reading obsolete node at %08x\n", ret, ref_offset(raw));
 833                                 /* If we can't read it, we don't need to continue to obsolete it. Continue */
 834                                 continue;
 835                         }
 836                         if (retlen != rawlen) {
 837                                 printk(KERN_WARNING "jffs2_g_c_deletion_dirent(): Short read (%zd not %u) reading header from obsolete node at %08x\n",
 838                                        retlen, rawlen, ref_offset(raw));
 839                                 continue;
 840                         }
 841
 842                         if (je16_to_cpu(rd->nodetype) != JFFS2_NODETYPE_DIRENT)
 843                                 continue;
 844
 845                         /* If the name CRC doesn't match, skip */
 846                         if (je32_to_cpu(rd->name_crc) != name_crc)
 847                                 continue;
 848
 849                         /* If the name length doesn't match, or it's another deletion dirent, skip */
 850                         if (rd->nsize != name_len || !je32_to_cpu(rd->ino))
 851                                 continue;
 852
 853                         /* OK, check the actual name now */
 854                         if (memcmp(rd->name, fd->name, name_len))
 855                                 continue;
 856
 857                         /* OK. The name really does match. There really is still an older node on
 858                            the flash which our deletion dirent obsoletes. So we have to write out
 859                            a new deletion dirent to replace it */
 860                         up(&c->erase_free_sem);
 861
 862                         D1(printk(KERN_DEBUG "Deletion dirent at %08x still obsoletes real dirent \"%s\" at %08x for ino #%u\n",
 863                                   ref_offset(fd->raw), fd->name, ref_offset(raw), je32_to_cpu(rd->ino)));
 864                         kfree(rd);
 865
 866                         return jffs2_garbage_collect_dirent(c, jeb, f, fd);
 867                 }
 868
 869                 up(&c->erase_free_sem);
 870                 kfree(rd);
 871         }
 872
 873         /* No need for it any more. Just mark it obsolete and remove it from the list */
 874         while (*fdp) {
 875                 if ((*fdp) == fd) {
 876                         found = 1;
 877                         *fdp = fd->next;
 878                         break;
 879                 }
 880                 fdp = &(*fdp)->next;
 881         }
 882         if (!found) {
 883                 printk(KERN_WARNING "Deletion dirent \"%s\" not found in list for ino #%u\n", fd->name, f->inocache->ino);
 884         }
 885         jffs2_mark_node_obsolete(c, fd->raw);
 886         jffs2_free_full_dirent(fd);
 887         return 0;
 888 }
 889
 890 static int jffs2_garbage_collect_hole(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 891                                       struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
 892                                       uint32_t start, uint32_t end)
 893 {
 894         struct jffs2_raw_inode ri;
 895         struct jffs2_node_frag *frag;
 896         struct jffs2_full_dnode *new_fn;
 897         uint32_t alloclen, phys_ofs;
 898         int ret;
 899
 900         D1(printk(KERN_DEBUG "Writing replacement hole node for ino #%u from offset 0x%x to 0x%x\n",
 901                   f->inocache->ino, start, end));
 902
 903         memset(&ri, 0, sizeof(ri));
 904
 905         if(fn->frags > 1) {
 906                 size_t readlen;
 907                 uint32_t crc;
 908                 /* It's partially obsoleted by a later write. So we have to
 909                    write it out again with the _same_ version as before */
 910                 ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(ri), &readlen, (char *)&ri);
 911                 if (readlen != sizeof(ri) || ret) {
 912                         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);
 913                         goto fill;
 914                 }
 915                 if (je16_to_cpu(ri.nodetype) != JFFS2_NODETYPE_INODE) {
 916                         printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had node type 0x%04x instead of JFFS2_NODETYPE_INODE(0x%04x)\n",
 917                                ref_offset(fn->raw),
 918                                je16_to_cpu(ri.nodetype), JFFS2_NODETYPE_INODE);
 919                         return -EIO;
 920                 }
 921                 if (je32_to_cpu(ri.totlen) != sizeof(ri)) {
 922                         printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had totlen 0x%x instead of expected 0x%zx\n",
 923                                ref_offset(fn->raw),
 924                                je32_to_cpu(ri.totlen), sizeof(ri));
 925                         return -EIO;
 926                 }
 927                 crc = crc32(0, &ri, sizeof(ri)-8);
 928                 if (crc != je32_to_cpu(ri.node_crc)) {
 929 #if 0   // mask by Victor Yu. 04-07-2007
 930                         printk(KERN_WARNING "jffs2_garbage_collect_hole: Node at 0x%08x had CRC 0x%08x which doesn't match calculated CRC 0x%08x\n",
 931                                ref_offset(fn->raw),
 932                                je32_to_cpu(ri.node_crc), crc);
 933                         /* FIXME: We could possibly deal with this by writing new holes for each frag */
 934                         printk(KERN_WARNING "Data in the range 0x%08x to 0x%08x of inode #%u will be lost\n",
 935                                start, end, f->inocache->ino);
 936 #endif
 937                         goto fill;
 938                 }
 939                 if (ri.compr != JFFS2_COMPR_ZERO) {
 940                         printk(KERN_WARNING "jffs2_garbage_collect_hole: Node 0x%08x wasn't a hole node!\n", ref_offset(fn->raw));
 941                         printk(KERN_WARNING "Data in the range 0x%08x to 0x%08x of inode #%u will be lost\n",
 942                                start, end, f->inocache->ino);
 943                         goto fill;
 944                 }
 945         } else {
 946         fill:
 947                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 948                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
 949                 ri.totlen = cpu_to_je32(sizeof(ri));
 950                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
 951
 952                 ri.ino = cpu_to_je32(f->inocache->ino);
 953                 ri.version = cpu_to_je32(++f->highest_version);
 954                 ri.offset = cpu_to_je32(start);
 955                 ri.dsize = cpu_to_je32(end - start);
 956                 ri.csize = cpu_to_je32(0);
 957                 ri.compr = JFFS2_COMPR_ZERO;
 958         }
 959         ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
 960         ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
 961         ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
 962         ri.isize = cpu_to_je32(JFFS2_F_I_SIZE(f));
 963         ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
 964         ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
 965         ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
 966         ri.data_crc = cpu_to_je32(0);
 967         ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
 968
 969         ret = jffs2_reserve_space_gc(c, sizeof(ri), &phys_ofs, &alloclen);
 970         if (ret) {
 971                 printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_hole failed: %d\n",
 972                        sizeof(ri), ret);
 973                 return ret;
 974         }
 975         new_fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_GC);
 976
 977         if (IS_ERR(new_fn)) {
 978                 printk(KERN_WARNING "Error writing new hole node: %ld\n", PTR_ERR(new_fn));
 979                 return PTR_ERR(new_fn);
 980         }
 981         if (je32_to_cpu(ri.version) == f->highest_version) {
 982                 jffs2_add_full_dnode_to_inode(c, f, new_fn);
 983                 if (f->metadata) {
 984                         jffs2_mark_node_obsolete(c, f->metadata->raw);
 985                         jffs2_free_full_dnode(f->metadata);
 986                         f->metadata = NULL;
 987                 }
 988                 return 0;
 989         }
 990
 991         /*
 992          * We should only get here in the case where the node we are
 993          * replacing had more than one frag, so we kept the same version
 994          * number as before. (Except in case of error -- see 'goto fill;'
 995          * above.)
 996          */
 997         D1(if(unlikely(fn->frags <= 1)) {
 998                 printk(KERN_WARNING "jffs2_garbage_collect_hole: Replacing fn with %d frag(s) but new ver %d != highest_version %d of ino #%d\n",
 999                        fn->frags, je32_to_cpu(ri.version), f->highest_version,
1000                        je32_to_cpu(ri.ino));
1001         });
1002
1003         /* This is a partially-overlapped hole node. Mark it REF_NORMAL not REF_PRISTINE */
1004         mark_ref_normal(new_fn->raw);
1005
1006         for (frag = jffs2_lookup_node_frag(&f->fragtree, fn->ofs);
1007              frag; frag = frag_next(frag)) {
1008                 if (frag->ofs > fn->size + fn->ofs)
1009                         break;
1010                 if (frag->node == fn) {
1011                         frag->node = new_fn;
1012                         new_fn->frags++;
1013                         fn->frags--;
1014                 }
1015         }
1016         if (fn->frags) {
1017                 printk(KERN_WARNING "jffs2_garbage_collect_hole: Old node still has frags!\n");
1018                 BUG();
1019         }
1020         if (!new_fn->frags) {
1021                 printk(KERN_WARNING "jffs2_garbage_collect_hole: New node has no frags!\n");
1022                 BUG();
1023         }
1024
1025         jffs2_mark_node_obsolete(c, fn->raw);
1026         jffs2_free_full_dnode(fn);
1027
1028         return 0;
1029 }
1030
1031 static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1032                                        struct jffs2_inode_info *f, struct jffs2_full_dnode *fn,
1033                                        uint32_t start, uint32_t end)
1034 {
1035         struct jffs2_full_dnode *new_fn;
1036         struct jffs2_raw_inode ri;
1037         uint32_t alloclen, phys_ofs, offset, orig_end, orig_start;
1038         int ret = 0;
1039         unsigned char *comprbuf = NULL, *writebuf;
1040         unsigned long pg;
1041         unsigned char *pg_ptr;
1042
1043         memset(&ri, 0, sizeof(ri));
1044
1045         D1(printk(KERN_DEBUG "Writing replacement dnode for ino #%u from offset 0x%x to 0x%x\n",
1046                   f->inocache->ino, start, end));
1047
1048         orig_end = end;
1049         orig_start = start;
1050
1051         if (c->nr_free_blocks + c->nr_erasing_blocks > c->resv_blocks_gcmerge) {
1052                 /* Attempt to do some merging. But only expand to cover logically
1053                    adjacent frags if the block containing them is already considered
1054                    to be dirty. Otherwise we end up with GC just going round in
1055                    circles dirtying the nodes it already wrote out, especially
1056                    on NAND where we have small eraseblocks and hence a much higher
1057                    chance of nodes having to be split to cross boundaries. */
1058
1059                 struct jffs2_node_frag *frag;
1060                 uint32_t min, max;
1061
1062                 min = start & ~(PAGE_CACHE_SIZE-1);
1063                 max = min + PAGE_CACHE_SIZE;
1064
1065                 frag = jffs2_lookup_node_frag(&f->fragtree, start);
1066
1067                 /* BUG_ON(!frag) but that'll happen anyway... */
1068
1069                 BUG_ON(frag->ofs != start);
1070
1071                 /* First grow down... */
1072                 while((frag = frag_prev(frag)) && frag->ofs >= min) {
1073
1074                         /* If the previous frag doesn't even reach the beginning, there's
1075                            excessive fragmentation. Just merge. */
1076                         if (frag->ofs > min) {
1077                                 D1(printk(KERN_DEBUG "Expanding down to cover partial frag (0x%x-0x%x)\n",
1078                                           frag->ofs, frag->ofs+frag->size));
1079                                 start = frag->ofs;
1080                                 continue;
1081                         }
1082                         /* OK. This frag holds the first byte of the page. */
1083                         if (!frag->node || !frag->node->raw) {
1084                                 D1(printk(KERN_DEBUG "First frag in page is hole (0x%x-0x%x). Not expanding down.\n",
1085                                           frag->ofs, frag->ofs+frag->size));
1086                                 break;
1087                         } else {
1088
1089                                 /* OK, it's a frag which extends to the beginning of the page. Does it live
1090                                    in a block which is still considered clean? If so, don't obsolete it.
1091                                    If not, cover it anyway. */
1092
1093                                 struct jffs2_raw_node_ref *raw = frag->node->raw;
1094                                 struct jffs2_eraseblock *jeb;
1095
1096                                 jeb = &c->blocks[raw->flash_offset / c->sector_size];
1097
1098                                 if (jeb == c->gcblock) {
1099                                         D1(printk(KERN_DEBUG "Expanding down to cover frag (0x%x-0x%x) in gcblock at %08x\n",
1100                                                   frag->ofs, frag->ofs+frag->size, ref_offset(raw)));
1101                                         start = frag->ofs;
1102                                         break;
1103                                 }
1104                                 if (!ISDIRTY(jeb->dirty_size + jeb->wasted_size)) {
1105                                         D1(printk(KERN_DEBUG "Not expanding down to cover frag (0x%x-0x%x) in clean block %08x\n",
1106                                                   frag->ofs, frag->ofs+frag->size, jeb->offset));
1107                                         break;
1108                                 }
1109
1110                                 D1(printk(KERN_DEBUG "Expanding down to cover frag (0x%x-0x%x) in dirty block %08x\n",
1111                                                   frag->ofs, frag->ofs+frag->size, jeb->offset));
1112                                 start = frag->ofs;
1113                                 break;
1114                         }
1115                 }
1116
1117                 /* ... then up */
1118
1119                 /* Find last frag which is actually part of the node we're to GC. */
1120                 frag = jffs2_lookup_node_frag(&f->fragtree, end-1);
1121
1122                 while((frag = frag_next(frag)) && frag->ofs+frag->size <= max) {
1123
1124                         /* If the previous frag doesn't even reach the beginning, there's lots
1125                            of fragmentation. Just merge. */
1126                         if (frag->ofs+frag->size < max) {
1127                                 D1(printk(KERN_DEBUG "Expanding up to cover partial frag (0x%x-0x%x)\n",
1128                                           frag->ofs, frag->ofs+frag->size));
1129                                 end = frag->ofs + frag->size;
1130                                 continue;
1131                         }
1132
1133                         if (!frag->node || !frag->node->raw) {
1134                                 D1(printk(KERN_DEBUG "Last frag in page is hole (0x%x-0x%x). Not expanding up.\n",
1135                                           frag->ofs, frag->ofs+frag->size));
1136                                 break;
1137                         } else {
1138
1139                                 /* OK, it's a frag which extends to the beginning of the page. Does it live
1140                                    in a block which is still considered clean? If so, don't obsolete it.
1141                                    If not, cover it anyway. */
1142
1143                                 struct jffs2_raw_node_ref *raw = frag->node->raw;
1144                                 struct jffs2_eraseblock *jeb;
1145
1146                                 jeb = &c->blocks[raw->flash_offset / c->sector_size];
1147
1148                                 if (jeb == c->gcblock) {
1149                                         D1(printk(KERN_DEBUG "Expanding up to cover frag (0x%x-0x%x) in gcblock at %08x\n",
1150                                                   frag->ofs, frag->ofs+frag->size, ref_offset(raw)));
1151                                         end = frag->ofs + frag->size;
1152                                         break;
1153                                 }
1154                                 if (!ISDIRTY(jeb->dirty_size + jeb->wasted_size)) {
1155                                         D1(printk(KERN_DEBUG "Not expanding up to cover frag (0x%x-0x%x) in clean block %08x\n",
1156                                                   frag->ofs, frag->ofs+frag->size, jeb->offset));
1157                                         break;
1158                                 }
1159
1160                                 D1(printk(KERN_DEBUG "Expanding up to cover frag (0x%x-0x%x) in dirty block %08x\n",
1161                                                   frag->ofs, frag->ofs+frag->size, jeb->offset));
1162                                 end = frag->ofs + frag->size;
1163                                 break;
1164                         }
1165                 }
1166                 D1(printk(KERN_DEBUG "Expanded dnode to write from (0x%x-0x%x) to (0x%x-0x%x)\n",
1167                           orig_start, orig_end, start, end));
1168
1169                 BUG_ON(end > JFFS2_F_I_SIZE(f));
1170                 BUG_ON(end < orig_end);
1171                 BUG_ON(start > orig_start);
1172         }
1173
1174         /* First, use readpage() to read the appropriate page into the page cache */
1175         /* Q: What happens if we actually try to GC the _same_ page for which commit_write()
1176          *    triggered garbage collection in the first place?
1177          * A: I _think_ it's OK. read_cache_page shouldn't deadlock, we'll write out the
1178          *    page OK. We'll actually write it out again in commit_write, which is a little
1179          *    suboptimal, but at least we're correct.
1180          */
1181         pg_ptr = jffs2_gc_fetch_page(c, f, start, &pg);
1182
1183         if (IS_ERR(pg_ptr)) {
1184                 printk(KERN_WARNING "read_cache_page() returned error: %ld\n", PTR_ERR(pg_ptr));
1185                 return PTR_ERR(pg_ptr);
1186         }
1187
1188         offset = start;
1189         while(offset < orig_end) {
1190                 uint32_t datalen;
1191                 uint32_t cdatalen;
1192                 uint16_t comprtype = JFFS2_COMPR_NONE;
1193
1194                 ret = jffs2_reserve_space_gc(c, sizeof(ri) + JFFS2_MIN_DATA_LEN, &phys_ofs, &alloclen);
1195
1196                 if (ret) {
1197                         printk(KERN_WARNING "jffs2_reserve_space_gc of %zd bytes for garbage_collect_dnode failed: %d\n",
1198                                sizeof(ri)+ JFFS2_MIN_DATA_LEN, ret);
1199                         break;
1200                 }
1201                 cdatalen = min_t(uint32_t, alloclen - sizeof(ri), end - offset);
1202                 datalen = end - offset;
1203
1204                 writebuf = pg_ptr + (offset & (PAGE_CACHE_SIZE -1));
1205
1206                 comprtype = jffs2_compress(c, f, writebuf, &comprbuf, &datalen, &cdatalen);
1207
1208                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
1209                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
1210                 ri.totlen = cpu_to_je32(sizeof(ri) + cdatalen);
1211                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
1212
1213                 ri.ino = cpu_to_je32(f->inocache->ino);
1214                 ri.version = cpu_to_je32(++f->highest_version);
1215                 ri.mode = cpu_to_jemode(JFFS2_F_I_MODE(f));
1216                 ri.uid = cpu_to_je16(JFFS2_F_I_UID(f));
1217                 ri.gid = cpu_to_je16(JFFS2_F_I_GID(f));
1218                 ri.isize = cpu_to_je32(JFFS2_F_I_SIZE(f));
1219                 ri.atime = cpu_to_je32(JFFS2_F_I_ATIME(f));
1220                 ri.ctime = cpu_to_je32(JFFS2_F_I_CTIME(f));
1221                 ri.mtime = cpu_to_je32(JFFS2_F_I_MTIME(f));
1222                 ri.offset = cpu_to_je32(offset);
1223                 ri.csize = cpu_to_je32(cdatalen);
1224                 ri.dsize = cpu_to_je32(datalen);
1225                 ri.compr = comprtype & 0xff;
1226                 ri.usercompr = (comprtype >> 8) & 0xff;
1227                 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
1228                 ri.data_crc = cpu_to_je32(crc32(0, comprbuf, cdatalen));
1229
1230                 new_fn = jffs2_write_dnode(c, f, &ri, comprbuf, cdatalen, phys_ofs, ALLOC_GC);
1231
1232                 jffs2_free_comprbuf(comprbuf, writebuf);
1233
1234                 if (IS_ERR(new_fn)) {
1235                         printk(KERN_WARNING "Error writing new dnode: %ld\n", PTR_ERR(new_fn));
1236                         ret = PTR_ERR(new_fn);
1237                         break;
1238                 }
1239                 ret = jffs2_add_full_dnode_to_inode(c, f, new_fn);
1240                 offset += datalen;
1241                 if (f->metadata) {
1242                         jffs2_mark_node_obsolete(c, f->metadata->raw);
1243                         jffs2_free_full_dnode(f->metadata);
1244                         f->metadata = NULL;
1245                 }
1246         }
1247
1248         jffs2_gc_release_page(c, pg_ptr, &pg);
1249         return ret;
1250 }
1251