~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/jffs2/scan.c

Version: ~ [ linux-5.3 ] ~ [ linux-5.2.15 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.73 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.144 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.193 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.193 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.73 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * JFFS2 -- Journalling Flash File System, Version 2.
  3  *
  4  * Copyright © 2001-2007 Red Hat, Inc.
  5  *
  6  * Created by David Woodhouse <dwmw2@infradead.org>
  7  *
  8  * For licensing information, see the file 'LICENCE' in this directory.
  9  *
 10  */
 11 
 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13 
 14 #include <linux/kernel.h>
 15 #include <linux/sched.h>
 16 #include <linux/slab.h>
 17 #include <linux/mtd/mtd.h>
 18 #include <linux/pagemap.h>
 19 #include <linux/crc32.h>
 20 #include <linux/compiler.h>
 21 #include "nodelist.h"
 22 #include "summary.h"
 23 #include "debug.h"
 24 
 25 #define DEFAULT_EMPTY_SCAN_SIZE 256
 26 
 27 #define noisy_printk(noise, fmt, ...)                                   \
 28 do {                                                                    \
 29         if (*(noise)) {                                                 \
 30                 pr_notice(fmt, ##__VA_ARGS__);                          \
 31                 (*(noise))--;                                           \
 32                 if (!(*(noise)))                                        \
 33                         pr_notice("Further such events for this erase block will not be printed\n"); \
 34         }                                                               \
 35 } while (0)
 36 
 37 static uint32_t pseudo_random;
 38 
 39 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 40                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
 41 
 42 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
 43  * Returning an error will abort the mount - bad checksums etc. should just mark the space
 44  * as dirty.
 45  */
 46 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 47                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
 48 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 49                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
 50 
 51 static inline int min_free(struct jffs2_sb_info *c)
 52 {
 53         uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
 54 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 55         if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
 56                 return c->wbuf_pagesize;
 57 #endif
 58         return min;
 59 
 60 }
 61 
 62 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
 63         if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
 64                 return sector_size;
 65         else
 66                 return DEFAULT_EMPTY_SCAN_SIZE;
 67 }
 68 
 69 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 70 {
 71         int ret;
 72 
 73         if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
 74                 return ret;
 75         if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
 76                 return ret;
 77         /* Turned wasted size into dirty, since we apparently 
 78            think it's recoverable now. */
 79         jeb->dirty_size += jeb->wasted_size;
 80         c->dirty_size += jeb->wasted_size;
 81         c->wasted_size -= jeb->wasted_size;
 82         jeb->wasted_size = 0;
 83         if (VERYDIRTY(c, jeb->dirty_size)) {
 84                 list_add(&jeb->list, &c->very_dirty_list);
 85         } else {
 86                 list_add(&jeb->list, &c->dirty_list);
 87         }
 88         return 0;
 89 }
 90 
 91 int jffs2_scan_medium(struct jffs2_sb_info *c)
 92 {
 93         int i, ret;
 94         uint32_t empty_blocks = 0, bad_blocks = 0;
 95         unsigned char *flashbuf = NULL;
 96         uint32_t buf_size = 0;
 97         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
 98 #ifndef __ECOS
 99         size_t pointlen, try_size;
100 
101         ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
102                         (void **)&flashbuf, NULL);
103         if (!ret && pointlen < c->mtd->size) {
104                 /* Don't muck about if it won't let us point to the whole flash */
105                 jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
106                           pointlen);
107                 mtd_unpoint(c->mtd, 0, pointlen);
108                 flashbuf = NULL;
109         }
110         if (ret && ret != -EOPNOTSUPP)
111                 jffs2_dbg(1, "MTD point failed %d\n", ret);
112 #endif
113         if (!flashbuf) {
114                 /* For NAND it's quicker to read a whole eraseblock at a time,
115                    apparently */
116                 if (jffs2_cleanmarker_oob(c))
117                         try_size = c->sector_size;
118                 else
119                         try_size = PAGE_SIZE;
120 
121                 jffs2_dbg(1, "Trying to allocate readbuf of %zu "
122                           "bytes\n", try_size);
123 
124                 flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
125                 if (!flashbuf)
126                         return -ENOMEM;
127 
128                 jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
129                           try_size);
130 
131                 buf_size = (uint32_t)try_size;
132         }
133 
134         if (jffs2_sum_active()) {
135                 s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
136                 if (!s) {
137                         JFFS2_WARNING("Can't allocate memory for summary\n");
138                         ret = -ENOMEM;
139                         goto out;
140                 }
141         }
142 
143         for (i=0; i<c->nr_blocks; i++) {
144                 struct jffs2_eraseblock *jeb = &c->blocks[i];
145 
146                 cond_resched();
147 
148                 /* reset summary info for next eraseblock scan */
149                 jffs2_sum_reset_collected(s);
150 
151                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
152                                                 buf_size, s);
153 
154                 if (ret < 0)
155                         goto out;
156 
157                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
158 
159                 /* Now decide which list to put it on */
160                 switch(ret) {
161                 case BLK_STATE_ALLFF:
162                         /*
163                          * Empty block.   Since we can't be sure it
164                          * was entirely erased, we just queue it for erase
165                          * again.  It will be marked as such when the erase
166                          * is complete.  Meanwhile we still count it as empty
167                          * for later checks.
168                          */
169                         empty_blocks++;
170                         list_add(&jeb->list, &c->erase_pending_list);
171                         c->nr_erasing_blocks++;
172                         break;
173 
174                 case BLK_STATE_CLEANMARKER:
175                         /* Only a CLEANMARKER node is valid */
176                         if (!jeb->dirty_size) {
177                                 /* It's actually free */
178                                 list_add(&jeb->list, &c->free_list);
179                                 c->nr_free_blocks++;
180                         } else {
181                                 /* Dirt */
182                                 jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
183                                           jeb->offset);
184                                 list_add(&jeb->list, &c->erase_pending_list);
185                                 c->nr_erasing_blocks++;
186                         }
187                         break;
188 
189                 case BLK_STATE_CLEAN:
190                         /* Full (or almost full) of clean data. Clean list */
191                         list_add(&jeb->list, &c->clean_list);
192                         break;
193 
194                 case BLK_STATE_PARTDIRTY:
195                         /* Some data, but not full. Dirty list. */
196                         /* We want to remember the block with most free space
197                         and stick it in the 'nextblock' position to start writing to it. */
198                         if (jeb->free_size > min_free(c) &&
199                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
200                                 /* Better candidate for the next writes to go to */
201                                 if (c->nextblock) {
202                                         ret = file_dirty(c, c->nextblock);
203                                         if (ret)
204                                                 goto out;
205                                         /* deleting summary information of the old nextblock */
206                                         jffs2_sum_reset_collected(c->summary);
207                                 }
208                                 /* update collected summary information for the current nextblock */
209                                 jffs2_sum_move_collected(c, s);
210                                 jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
211                                           __func__, jeb->offset);
212                                 c->nextblock = jeb;
213                         } else {
214                                 ret = file_dirty(c, jeb);
215                                 if (ret)
216                                         goto out;
217                         }
218                         break;
219 
220                 case BLK_STATE_ALLDIRTY:
221                         /* Nothing valid - not even a clean marker. Needs erasing. */
222                         /* For now we just put it on the erasing list. We'll start the erases later */
223                         jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
224                                   jeb->offset);
225                         list_add(&jeb->list, &c->erase_pending_list);
226                         c->nr_erasing_blocks++;
227                         break;
228 
229                 case BLK_STATE_BADBLOCK:
230                         jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
231                         list_add(&jeb->list, &c->bad_list);
232                         c->bad_size += c->sector_size;
233                         c->free_size -= c->sector_size;
234                         bad_blocks++;
235                         break;
236                 default:
237                         pr_warn("%s(): unknown block state\n", __func__);
238                         BUG();
239                 }
240         }
241 
242         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
243         if (c->nextblock && (c->nextblock->dirty_size)) {
244                 c->nextblock->wasted_size += c->nextblock->dirty_size;
245                 c->wasted_size += c->nextblock->dirty_size;
246                 c->dirty_size -= c->nextblock->dirty_size;
247                 c->nextblock->dirty_size = 0;
248         }
249 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
250         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
251                 /* If we're going to start writing into a block which already
252                    contains data, and the end of the data isn't page-aligned,
253                    skip a little and align it. */
254 
255                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
256 
257                 jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
258                           __func__, skip);
259                 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
260                 jffs2_scan_dirty_space(c, c->nextblock, skip);
261         }
262 #endif
263         if (c->nr_erasing_blocks) {
264                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
265                         pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
266                         pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
267                                   empty_blocks, bad_blocks, c->nr_blocks);
268                         ret = -EIO;
269                         goto out;
270                 }
271                 spin_lock(&c->erase_completion_lock);
272                 jffs2_garbage_collect_trigger(c);
273                 spin_unlock(&c->erase_completion_lock);
274         }
275         ret = 0;
276  out:
277         if (buf_size)
278                 kfree(flashbuf);
279 #ifndef __ECOS
280         else
281                 mtd_unpoint(c->mtd, 0, c->mtd->size);
282 #endif
283         kfree(s);
284         return ret;
285 }
286 
287 static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
288                                uint32_t ofs, uint32_t len)
289 {
290         int ret;
291         size_t retlen;
292 
293         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
294         if (ret) {
295                 jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
296                           len, ofs, ret);
297                 return ret;
298         }
299         if (retlen < len) {
300                 jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
301                           ofs, retlen);
302                 return -EIO;
303         }
304         return 0;
305 }
306 
307 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
308 {
309         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
310             && (!jeb->first_node || !ref_next(jeb->first_node)) )
311                 return BLK_STATE_CLEANMARKER;
312 
313         /* move blocks with max 4 byte dirty space to cleanlist */
314         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
315                 c->dirty_size -= jeb->dirty_size;
316                 c->wasted_size += jeb->dirty_size;
317                 jeb->wasted_size += jeb->dirty_size;
318                 jeb->dirty_size = 0;
319                 return BLK_STATE_CLEAN;
320         } else if (jeb->used_size || jeb->unchecked_size)
321                 return BLK_STATE_PARTDIRTY;
322         else
323                 return BLK_STATE_ALLDIRTY;
324 }
325 
326 #ifdef CONFIG_JFFS2_FS_XATTR
327 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
328                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
329                                  struct jffs2_summary *s)
330 {
331         struct jffs2_xattr_datum *xd;
332         uint32_t xid, version, totlen, crc;
333         int err;
334 
335         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
336         if (crc != je32_to_cpu(rx->node_crc)) {
337                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
338                               ofs, je32_to_cpu(rx->node_crc), crc);
339                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
340                         return err;
341                 return 0;
342         }
343 
344         xid = je32_to_cpu(rx->xid);
345         version = je32_to_cpu(rx->version);
346 
347         totlen = PAD(sizeof(struct jffs2_raw_xattr)
348                         + rx->name_len + 1 + je16_to_cpu(rx->value_len));
349         if (totlen != je32_to_cpu(rx->totlen)) {
350                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
351                               ofs, je32_to_cpu(rx->totlen), totlen);
352                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
353                         return err;
354                 return 0;
355         }
356 
357         xd = jffs2_setup_xattr_datum(c, xid, version);
358         if (IS_ERR(xd))
359                 return PTR_ERR(xd);
360 
361         if (xd->version > version) {
362                 struct jffs2_raw_node_ref *raw
363                         = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
364                 raw->next_in_ino = xd->node->next_in_ino;
365                 xd->node->next_in_ino = raw;
366         } else {
367                 xd->version = version;
368                 xd->xprefix = rx->xprefix;
369                 xd->name_len = rx->name_len;
370                 xd->value_len = je16_to_cpu(rx->value_len);
371                 xd->data_crc = je32_to_cpu(rx->data_crc);
372 
373                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
374         }
375 
376         if (jffs2_sum_active())
377                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
378         dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
379                   ofs, xd->xid, xd->version);
380         return 0;
381 }
382 
383 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
384                                 struct jffs2_raw_xref *rr, uint32_t ofs,
385                                 struct jffs2_summary *s)
386 {
387         struct jffs2_xattr_ref *ref;
388         uint32_t crc;
389         int err;
390 
391         crc = crc32(0, rr, sizeof(*rr) - 4);
392         if (crc != je32_to_cpu(rr->node_crc)) {
393                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
394                               ofs, je32_to_cpu(rr->node_crc), crc);
395                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
396                         return err;
397                 return 0;
398         }
399 
400         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
401                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
402                               ofs, je32_to_cpu(rr->totlen),
403                               PAD(sizeof(struct jffs2_raw_xref)));
404                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
405                         return err;
406                 return 0;
407         }
408 
409         ref = jffs2_alloc_xattr_ref();
410         if (!ref)
411                 return -ENOMEM;
412 
413         /* BEFORE jffs2_build_xattr_subsystem() called, 
414          * and AFTER xattr_ref is marked as a dead xref,
415          * ref->xid is used to store 32bit xid, xd is not used
416          * ref->ino is used to store 32bit inode-number, ic is not used
417          * Thoes variables are declared as union, thus using those
418          * are exclusive. In a similar way, ref->next is temporarily
419          * used to chain all xattr_ref object. It's re-chained to
420          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
421          */
422         ref->ino = je32_to_cpu(rr->ino);
423         ref->xid = je32_to_cpu(rr->xid);
424         ref->xseqno = je32_to_cpu(rr->xseqno);
425         if (ref->xseqno > c->highest_xseqno)
426                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
427         ref->next = c->xref_temp;
428         c->xref_temp = ref;
429 
430         jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
431 
432         if (jffs2_sum_active())
433                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
434         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
435                   ofs, ref->xid, ref->ino);
436         return 0;
437 }
438 #endif
439 
440 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
441    the flash, XIP-style */
442 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
443                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
444         struct jffs2_unknown_node *node;
445         struct jffs2_unknown_node crcnode;
446         uint32_t ofs, prevofs, max_ofs;
447         uint32_t hdr_crc, buf_ofs, buf_len;
448         int err;
449         int noise = 0;
450 
451 
452 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
453         int cleanmarkerfound = 0;
454 #endif
455 
456         ofs = jeb->offset;
457         prevofs = jeb->offset - 1;
458 
459         jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
460 
461 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
462         if (jffs2_cleanmarker_oob(c)) {
463                 int ret;
464 
465                 if (mtd_block_isbad(c->mtd, jeb->offset))
466                         return BLK_STATE_BADBLOCK;
467 
468                 ret = jffs2_check_nand_cleanmarker(c, jeb);
469                 jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
470 
471                 /* Even if it's not found, we still scan to see
472                    if the block is empty. We use this information
473                    to decide whether to erase it or not. */
474                 switch (ret) {
475                 case 0:         cleanmarkerfound = 1; break;
476                 case 1:         break;
477                 default:        return ret;
478                 }
479         }
480 #endif
481 
482         if (jffs2_sum_active()) {
483                 struct jffs2_sum_marker *sm;
484                 void *sumptr = NULL;
485                 uint32_t sumlen;
486               
487                 if (!buf_size) {
488                         /* XIP case. Just look, point at the summary if it's there */
489                         sm = (void *)buf + c->sector_size - sizeof(*sm);
490                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
491                                 sumptr = buf + je32_to_cpu(sm->offset);
492                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
493                         }
494                 } else {
495                         /* If NAND flash, read a whole page of it. Else just the end */
496                         if (c->wbuf_pagesize)
497                                 buf_len = c->wbuf_pagesize;
498                         else
499                                 buf_len = sizeof(*sm);
500 
501                         /* Read as much as we want into the _end_ of the preallocated buffer */
502                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
503                                                   jeb->offset + c->sector_size - buf_len,
504                                                   buf_len);                             
505                         if (err)
506                                 return err;
507 
508                         sm = (void *)buf + buf_size - sizeof(*sm);
509                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
510                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
511                                 sumptr = buf + buf_size - sumlen;
512 
513                                 /* sm->offset maybe wrong but MAGIC maybe right */
514                                 if (sumlen > c->sector_size)
515                                         goto full_scan;
516 
517                                 /* Now, make sure the summary itself is available */
518                                 if (sumlen > buf_size) {
519                                         /* Need to kmalloc for this. */
520                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
521                                         if (!sumptr)
522                                                 return -ENOMEM;
523                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
524                                 }
525                                 if (buf_len < sumlen) {
526                                         /* Need to read more so that the entire summary node is present */
527                                         err = jffs2_fill_scan_buf(c, sumptr, 
528                                                                   jeb->offset + c->sector_size - sumlen,
529                                                                   sumlen - buf_len);                            
530                                         if (err)
531                                                 return err;
532                                 }
533                         }
534 
535                 }
536 
537                 if (sumptr) {
538                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
539 
540                         if (buf_size && sumlen > buf_size)
541                                 kfree(sumptr);
542                         /* If it returns with a real error, bail. 
543                            If it returns positive, that's a block classification
544                            (i.e. BLK_STATE_xxx) so return that too.
545                            If it returns zero, fall through to full scan. */
546                         if (err)
547                                 return err;
548                 }
549         }
550 
551 full_scan:
552         buf_ofs = jeb->offset;
553 
554         if (!buf_size) {
555                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
556                 buf_len = c->sector_size;
557         } else {
558                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
559                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
560                 if (err)
561                         return err;
562         }
563 
564         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
565         ofs = 0;
566         max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
567         /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
568         while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
569                 ofs += 4;
570 
571         if (ofs == max_ofs) {
572 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
573                 if (jffs2_cleanmarker_oob(c)) {
574                         /* scan oob, take care of cleanmarker */
575                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
576                         jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
577                                   ret);
578                         switch (ret) {
579                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
580                         case 1:         return BLK_STATE_ALLDIRTY;
581                         default:        return ret;
582                         }
583                 }
584 #endif
585                 jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
586                           jeb->offset);
587                 if (c->cleanmarker_size == 0)
588                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
589                 else
590                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
591         }
592         if (ofs) {
593                 jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
594                           jeb->offset + ofs);
595                 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
596                         return err;
597                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
598                         return err;
599         }
600 
601         /* Now ofs is a complete physical flash offset as it always was... */
602         ofs += jeb->offset;
603 
604         noise = 10;
605 
606         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
607 
608 scan_more:
609         while(ofs < jeb->offset + c->sector_size) {
610 
611                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
612 
613                 /* Make sure there are node refs available for use */
614                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
615                 if (err)
616                         return err;
617 
618                 cond_resched();
619 
620                 if (ofs & 3) {
621                         pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
622                         ofs = PAD(ofs);
623                         continue;
624                 }
625                 if (ofs == prevofs) {
626                         pr_warn("ofs 0x%08x has already been seen. Skipping\n",
627                                 ofs);
628                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
629                                 return err;
630                         ofs += 4;
631                         continue;
632                 }
633                 prevofs = ofs;
634 
635                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
636                         jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
637                                   sizeof(struct jffs2_unknown_node),
638                                   jeb->offset, c->sector_size, ofs,
639                                   sizeof(*node));
640                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
641                                 return err;
642                         break;
643                 }
644 
645                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
646                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
647                         jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
648                                   sizeof(struct jffs2_unknown_node),
649                                   buf_len, ofs);
650                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
651                         if (err)
652                                 return err;
653                         buf_ofs = ofs;
654                 }
655 
656                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
657 
658                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
659                         uint32_t inbuf_ofs;
660                         uint32_t empty_start, scan_end;
661 
662                         empty_start = ofs;
663                         ofs += 4;
664                         scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
665 
666                         jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
667                 more_empty:
668                         inbuf_ofs = ofs - buf_ofs;
669                         while (inbuf_ofs < scan_end) {
670                                 if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
671                                         pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
672                                                 empty_start, ofs);
673                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
674                                                 return err;
675                                         goto scan_more;
676                                 }
677 
678                                 inbuf_ofs+=4;
679                                 ofs += 4;
680                         }
681                         /* Ran off end. */
682                         jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
683                                   ofs);
684 
685                         /* If we're only checking the beginning of a block with a cleanmarker,
686                            bail now */
687                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
688                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
689                                 jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
690                                           EMPTY_SCAN_SIZE(c->sector_size));
691                                 return BLK_STATE_CLEANMARKER;
692                         }
693                         if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
694                                 scan_end = buf_len;
695                                 goto more_empty;
696                         }
697                         
698                         /* See how much more there is to read in this eraseblock... */
699                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
700                         if (!buf_len) {
701                                 /* No more to read. Break out of main loop without marking
702                                    this range of empty space as dirty (because it's not) */
703                                 jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
704                                           empty_start);
705                                 break;
706                         }
707                         /* point never reaches here */
708                         scan_end = buf_len;
709                         jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
710                                   buf_len, ofs);
711                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
712                         if (err)
713                                 return err;
714                         buf_ofs = ofs;
715                         goto more_empty;
716                 }
717 
718                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
719                         pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
720                                 ofs);
721                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
722                                 return err;
723                         ofs += 4;
724                         continue;
725                 }
726                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
727                         jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
728                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
729                                 return err;
730                         ofs += 4;
731                         continue;
732                 }
733                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
734                         pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
735                         pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
736                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
737                                 return err;
738                         ofs += 4;
739                         continue;
740                 }
741                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
742                         /* OK. We're out of possibilities. Whinge and move on */
743                         noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
744                                      __func__,
745                                      JFFS2_MAGIC_BITMASK, ofs,
746                                      je16_to_cpu(node->magic));
747                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
748                                 return err;
749                         ofs += 4;
750                         continue;
751                 }
752                 /* We seem to have a node of sorts. Check the CRC */
753                 crcnode.magic = node->magic;
754                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
755                 crcnode.totlen = node->totlen;
756                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
757 
758                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
759                         noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
760                                      __func__,
761                                      ofs, je16_to_cpu(node->magic),
762                                      je16_to_cpu(node->nodetype),
763                                      je32_to_cpu(node->totlen),
764                                      je32_to_cpu(node->hdr_crc),
765                                      hdr_crc);
766                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
767                                 return err;
768                         ofs += 4;
769                         continue;
770                 }
771 
772                 if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
773                         /* Eep. Node goes over the end of the erase block. */
774                         pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
775                                 ofs, je32_to_cpu(node->totlen));
776                         pr_warn("Perhaps the file system was created with the wrong erase size?\n");
777                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
778                                 return err;
779                         ofs += 4;
780                         continue;
781                 }
782 
783                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
784                         /* Wheee. This is an obsoleted node */
785                         jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
786                                   ofs);
787                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
788                                 return err;
789                         ofs += PAD(je32_to_cpu(node->totlen));
790                         continue;
791                 }
792 
793                 switch(je16_to_cpu(node->nodetype)) {
794                 case JFFS2_NODETYPE_INODE:
795                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
796                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
797                                 jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
798                                           sizeof(struct jffs2_raw_inode),
799                                           buf_len, ofs);
800                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
801                                 if (err)
802                                         return err;
803                                 buf_ofs = ofs;
804                                 node = (void *)buf;
805                         }
806                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
807                         if (err) return err;
808                         ofs += PAD(je32_to_cpu(node->totlen));
809                         break;
810 
811                 case JFFS2_NODETYPE_DIRENT:
812                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
813                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
814                                 jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
815                                           je32_to_cpu(node->totlen), buf_len,
816                                           ofs);
817                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
818                                 if (err)
819                                         return err;
820                                 buf_ofs = ofs;
821                                 node = (void *)buf;
822                         }
823                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
824                         if (err) return err;
825                         ofs += PAD(je32_to_cpu(node->totlen));
826                         break;
827 
828 #ifdef CONFIG_JFFS2_FS_XATTR
829                 case JFFS2_NODETYPE_XATTR:
830                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
831                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
832                                 jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
833                                           je32_to_cpu(node->totlen), buf_len,
834                                           ofs);
835                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
836                                 if (err)
837                                         return err;
838                                 buf_ofs = ofs;
839                                 node = (void *)buf;
840                         }
841                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
842                         if (err)
843                                 return err;
844                         ofs += PAD(je32_to_cpu(node->totlen));
845                         break;
846                 case JFFS2_NODETYPE_XREF:
847                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
848                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
849                                 jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
850                                           je32_to_cpu(node->totlen), buf_len,
851                                           ofs);
852                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
853                                 if (err)
854                                         return err;
855                                 buf_ofs = ofs;
856                                 node = (void *)buf;
857                         }
858                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
859                         if (err)
860                                 return err;
861                         ofs += PAD(je32_to_cpu(node->totlen));
862                         break;
863 #endif  /* CONFIG_JFFS2_FS_XATTR */
864 
865                 case JFFS2_NODETYPE_CLEANMARKER:
866                         jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
867                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
868                                 pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
869                                           ofs, je32_to_cpu(node->totlen),
870                                           c->cleanmarker_size);
871                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
872                                         return err;
873                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
874                         } else if (jeb->first_node) {
875                                 pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
876                                           ofs, jeb->offset);
877                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
878                                         return err;
879                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
880                         } else {
881                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
882 
883                                 ofs += PAD(c->cleanmarker_size);
884                         }
885                         break;
886 
887                 case JFFS2_NODETYPE_PADDING:
888                         if (jffs2_sum_active())
889                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
890                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
891                                 return err;
892                         ofs += PAD(je32_to_cpu(node->totlen));
893                         break;
894 
895                 default:
896                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
897                         case JFFS2_FEATURE_ROCOMPAT:
898                                 pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
899                                           je16_to_cpu(node->nodetype), ofs);
900                                 c->flags |= JFFS2_SB_FLAG_RO;
901                                 if (!(jffs2_is_readonly(c)))
902                                         return -EROFS;
903                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
904                                         return err;
905                                 ofs += PAD(je32_to_cpu(node->totlen));
906                                 break;
907 
908                         case JFFS2_FEATURE_INCOMPAT:
909                                 pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
910                                           je16_to_cpu(node->nodetype), ofs);
911                                 return -EINVAL;
912 
913                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
914                                 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
915                                           je16_to_cpu(node->nodetype), ofs);
916                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
917                                         return err;
918                                 ofs += PAD(je32_to_cpu(node->totlen));
919                                 break;
920 
921                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
922                                 jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
923                                           je16_to_cpu(node->nodetype), ofs);
924 
925                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
926 
927                                 /* We can't summarise nodes we don't grok */
928                                 jffs2_sum_disable_collecting(s);
929                                 ofs += PAD(je32_to_cpu(node->totlen));
930                                 break;
931                                 }
932                         }
933                 }
934         }
935 
936         if (jffs2_sum_active()) {
937                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
938                         dbg_summary("There is not enough space for "
939                                 "summary information, disabling for this jeb!\n");
940                         jffs2_sum_disable_collecting(s);
941                 }
942         }
943 
944         jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
945                   jeb->offset, jeb->free_size, jeb->dirty_size,
946                   jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
947         
948         /* mark_node_obsolete can add to wasted !! */
949         if (jeb->wasted_size) {
950                 jeb->dirty_size += jeb->wasted_size;
951                 c->dirty_size += jeb->wasted_size;
952                 c->wasted_size -= jeb->wasted_size;
953                 jeb->wasted_size = 0;
954         }
955 
956         return jffs2_scan_classify_jeb(c, jeb);
957 }
958 
959 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
960 {
961         struct jffs2_inode_cache *ic;
962 
963         ic = jffs2_get_ino_cache(c, ino);
964         if (ic)
965                 return ic;
966 
967         if (ino > c->highest_ino)
968                 c->highest_ino = ino;
969 
970         ic = jffs2_alloc_inode_cache();
971         if (!ic) {
972                 pr_notice("%s(): allocation of inode cache failed\n", __func__);
973                 return NULL;
974         }
975         memset(ic, 0, sizeof(*ic));
976 
977         ic->ino = ino;
978         ic->nodes = (void *)ic;
979         jffs2_add_ino_cache(c, ic);
980         if (ino == 1)
981                 ic->pino_nlink = 1;
982         return ic;
983 }
984 
985 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
986                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
987 {
988         struct jffs2_inode_cache *ic;
989         uint32_t crc, ino = je32_to_cpu(ri->ino);
990 
991         jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
992 
993         /* We do very little here now. Just check the ino# to which we should attribute
994            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
995            we used to scan the flash once only, reading everything we want from it into
996            memory, then building all our in-core data structures and freeing the extra
997            information. Now we allow the first part of the mount to complete a lot quicker,
998            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
999            Which means that the _full_ amount of time to get to proper write mode with GC
1000            operational may actually be _longer_ than before. Sucks to be me. */
1001 
1002         /* Check the node CRC in any case. */
1003         crc = crc32(0, ri, sizeof(*ri)-8);
1004         if (crc != je32_to_cpu(ri->node_crc)) {
1005                 pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1006                           __func__, ofs, je32_to_cpu(ri->node_crc), crc);
1007                 /*
1008                  * We believe totlen because the CRC on the node
1009                  * _header_ was OK, just the node itself failed.
1010                  */
1011                 return jffs2_scan_dirty_space(c, jeb,
1012                                               PAD(je32_to_cpu(ri->totlen)));
1013         }
1014 
1015         ic = jffs2_get_ino_cache(c, ino);
1016         if (!ic) {
1017                 ic = jffs2_scan_make_ino_cache(c, ino);
1018                 if (!ic)
1019                         return -ENOMEM;
1020         }
1021 
1022         /* Wheee. It worked */
1023         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1024 
1025         jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1026                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1027                   je32_to_cpu(ri->offset),
1028                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
1029 
1030         pseudo_random += je32_to_cpu(ri->version);
1031 
1032         if (jffs2_sum_active()) {
1033                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1034         }
1035 
1036         return 0;
1037 }
1038 
1039 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1040                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1041 {
1042         struct jffs2_full_dirent *fd;
1043         struct jffs2_inode_cache *ic;
1044         uint32_t checkedlen;
1045         uint32_t crc;
1046         int err;
1047 
1048         jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1049 
1050         /* We don't get here unless the node is still valid, so we don't have to
1051            mask in the ACCURATE bit any more. */
1052         crc = crc32(0, rd, sizeof(*rd)-8);
1053 
1054         if (crc != je32_to_cpu(rd->node_crc)) {
1055                 pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1056                           __func__, ofs, je32_to_cpu(rd->node_crc), crc);
1057                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1058                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1059                         return err;
1060                 return 0;
1061         }
1062 
1063         pseudo_random += je32_to_cpu(rd->version);
1064 
1065         /* Should never happen. Did. (OLPC trac #4184)*/
1066         checkedlen = strnlen(rd->name, rd->nsize);
1067         if (checkedlen < rd->nsize) {
1068                 pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1069                        ofs, checkedlen);
1070         }
1071         fd = jffs2_alloc_full_dirent(checkedlen+1);
1072         if (!fd) {
1073                 return -ENOMEM;
1074         }
1075         memcpy(&fd->name, rd->name, checkedlen);
1076         fd->name[checkedlen] = 0;
1077 
1078         crc = crc32(0, fd->name, rd->nsize);
1079         if (crc != je32_to_cpu(rd->name_crc)) {
1080                 pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1081                           __func__, ofs, je32_to_cpu(rd->name_crc), crc);
1082                 jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
1083                           fd->name, je32_to_cpu(rd->ino));
1084                 jffs2_free_full_dirent(fd);
1085                 /* FIXME: Why do we believe totlen? */
1086                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1087                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1088                         return err;
1089                 return 0;
1090         }
1091         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1092         if (!ic) {
1093                 jffs2_free_full_dirent(fd);
1094                 return -ENOMEM;
1095         }
1096 
1097         fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1098                                       PAD(je32_to_cpu(rd->totlen)), ic);
1099 
1100         fd->next = NULL;
1101         fd->version = je32_to_cpu(rd->version);
1102         fd->ino = je32_to_cpu(rd->ino);
1103         fd->nhash = full_name_hash(NULL, fd->name, checkedlen);
1104         fd->type = rd->type;
1105         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1106 
1107         if (jffs2_sum_active()) {
1108                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1109         }
1110 
1111         return 0;
1112 }
1113 
1114 static int count_list(struct list_head *l)
1115 {
1116         uint32_t count = 0;
1117         struct list_head *tmp;
1118 
1119         list_for_each(tmp, l) {
1120                 count++;
1121         }
1122         return count;
1123 }
1124 
1125 /* Note: This breaks if list_empty(head). I don't care. You
1126    might, if you copy this code and use it elsewhere :) */
1127 static void rotate_list(struct list_head *head, uint32_t count)
1128 {
1129         struct list_head *n = head->next;
1130 
1131         list_del(head);
1132         while(count--) {
1133                 n = n->next;
1134         }
1135         list_add(head, n);
1136 }
1137 
1138 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1139 {
1140         uint32_t x;
1141         uint32_t rotateby;
1142 
1143         x = count_list(&c->clean_list);
1144         if (x) {
1145                 rotateby = pseudo_random % x;
1146                 rotate_list((&c->clean_list), rotateby);
1147         }
1148 
1149         x = count_list(&c->very_dirty_list);
1150         if (x) {
1151                 rotateby = pseudo_random % x;
1152                 rotate_list((&c->very_dirty_list), rotateby);
1153         }
1154 
1155         x = count_list(&c->dirty_list);
1156         if (x) {
1157                 rotateby = pseudo_random % x;
1158                 rotate_list((&c->dirty_list), rotateby);
1159         }
1160 
1161         x = count_list(&c->erasable_list);
1162         if (x) {
1163                 rotateby = pseudo_random % x;
1164                 rotate_list((&c->erasable_list), rotateby);
1165         }
1166 
1167         if (c->nr_erasing_blocks) {
1168                 rotateby = pseudo_random % c->nr_erasing_blocks;
1169                 rotate_list((&c->erase_pending_list), rotateby);
1170         }
1171 
1172         if (c->nr_free_blocks) {
1173                 rotateby = pseudo_random % c->nr_free_blocks;
1174                 rotate_list((&c->free_list), rotateby);
1175         }
1176 }
1177 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp