Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
4 | * Copyright (C) 2001-2003 Red Hat, Inc. | |
5 | * | |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
daba5cc4 | 10 | * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $ |
1da177e4 LT |
11 | * |
12 | */ | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/mtd/mtd.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/crc32.h> | |
19 | #include <linux/compiler.h> | |
20 | #include "nodelist.h" | |
e631ddba FH |
21 | #include "summary.h" |
22 | #include "debug.h" | |
1da177e4 | 23 | |
3be36675 | 24 | #define DEFAULT_EMPTY_SCAN_SIZE 1024 |
1da177e4 | 25 | |
1da177e4 LT |
26 | #define noisy_printk(noise, args...) do { \ |
27 | if (*(noise)) { \ | |
28 | printk(KERN_NOTICE args); \ | |
29 | (*(noise))--; \ | |
30 | if (!(*(noise))) { \ | |
31 | printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \ | |
32 | } \ | |
33 | } \ | |
34 | } while(0) | |
35 | ||
36 | static uint32_t pseudo_random; | |
37 | ||
38 | static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, | |
e631ddba | 39 | unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s); |
1da177e4 | 40 | |
182ec4ee | 41 | /* These helper functions _must_ increase ofs and also do the dirty/used space accounting. |
1da177e4 LT |
42 | * Returning an error will abort the mount - bad checksums etc. should just mark the space |
43 | * as dirty. | |
44 | */ | |
182ec4ee | 45 | static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, |
e631ddba | 46 | struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s); |
1da177e4 | 47 | static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, |
e631ddba | 48 | struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s); |
1da177e4 LT |
49 | |
50 | static inline int min_free(struct jffs2_sb_info *c) | |
51 | { | |
52 | uint32_t min = 2 * sizeof(struct jffs2_raw_inode); | |
2f82ce1e | 53 | #ifdef CONFIG_JFFS2_FS_WRITEBUFFER |
1da177e4 LT |
54 | if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize) |
55 | return c->wbuf_pagesize; | |
56 | #endif | |
57 | return min; | |
58 | ||
59 | } | |
3be36675 AV |
60 | |
61 | static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) { | |
62 | if (sector_size < DEFAULT_EMPTY_SCAN_SIZE) | |
63 | return sector_size; | |
64 | else | |
65 | return DEFAULT_EMPTY_SCAN_SIZE; | |
66 | } | |
67 | ||
1da177e4 LT |
68 | int jffs2_scan_medium(struct jffs2_sb_info *c) |
69 | { | |
70 | int i, ret; | |
71 | uint32_t empty_blocks = 0, bad_blocks = 0; | |
72 | unsigned char *flashbuf = NULL; | |
73 | uint32_t buf_size = 0; | |
e631ddba | 74 | struct jffs2_summary *s = NULL; /* summary info collected by the scan process */ |
1da177e4 LT |
75 | #ifndef __ECOS |
76 | size_t pointlen; | |
77 | ||
78 | if (c->mtd->point) { | |
79 | ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf); | |
80 | if (!ret && pointlen < c->mtd->size) { | |
81 | /* Don't muck about if it won't let us point to the whole flash */ | |
82 | D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen)); | |
83 | c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size); | |
84 | flashbuf = NULL; | |
85 | } | |
86 | if (ret) | |
87 | D1(printk(KERN_DEBUG "MTD point failed %d\n", ret)); | |
88 | } | |
89 | #endif | |
90 | if (!flashbuf) { | |
91 | /* For NAND it's quicker to read a whole eraseblock at a time, | |
92 | apparently */ | |
93 | if (jffs2_cleanmarker_oob(c)) | |
94 | buf_size = c->sector_size; | |
95 | else | |
96 | buf_size = PAGE_SIZE; | |
97 | ||
98 | /* Respect kmalloc limitations */ | |
99 | if (buf_size > 128*1024) | |
100 | buf_size = 128*1024; | |
101 | ||
102 | D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size)); | |
103 | flashbuf = kmalloc(buf_size, GFP_KERNEL); | |
104 | if (!flashbuf) | |
105 | return -ENOMEM; | |
106 | } | |
107 | ||
e631ddba FH |
108 | if (jffs2_sum_active()) { |
109 | s = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL); | |
110 | if (!s) { | |
111 | JFFS2_WARNING("Can't allocate memory for summary\n"); | |
112 | return -ENOMEM; | |
113 | } | |
114 | memset(s, 0, sizeof(struct jffs2_summary)); | |
115 | } | |
116 | ||
1da177e4 LT |
117 | for (i=0; i<c->nr_blocks; i++) { |
118 | struct jffs2_eraseblock *jeb = &c->blocks[i]; | |
119 | ||
e631ddba FH |
120 | /* reset summary info for next eraseblock scan */ |
121 | jffs2_sum_reset_collected(s); | |
122 | ||
123 | ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset), | |
124 | buf_size, s); | |
1da177e4 LT |
125 | |
126 | if (ret < 0) | |
127 | goto out; | |
128 | ||
e0c8e42f | 129 | jffs2_dbg_acct_paranoia_check_nolock(c, jeb); |
1da177e4 LT |
130 | |
131 | /* Now decide which list to put it on */ | |
132 | switch(ret) { | |
133 | case BLK_STATE_ALLFF: | |
182ec4ee TG |
134 | /* |
135 | * Empty block. Since we can't be sure it | |
1da177e4 LT |
136 | * was entirely erased, we just queue it for erase |
137 | * again. It will be marked as such when the erase | |
138 | * is complete. Meanwhile we still count it as empty | |
139 | * for later checks. | |
140 | */ | |
141 | empty_blocks++; | |
142 | list_add(&jeb->list, &c->erase_pending_list); | |
143 | c->nr_erasing_blocks++; | |
144 | break; | |
145 | ||
146 | case BLK_STATE_CLEANMARKER: | |
147 | /* Only a CLEANMARKER node is valid */ | |
148 | if (!jeb->dirty_size) { | |
149 | /* It's actually free */ | |
150 | list_add(&jeb->list, &c->free_list); | |
151 | c->nr_free_blocks++; | |
152 | } else { | |
153 | /* Dirt */ | |
154 | D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset)); | |
155 | list_add(&jeb->list, &c->erase_pending_list); | |
156 | c->nr_erasing_blocks++; | |
157 | } | |
158 | break; | |
159 | ||
160 | case BLK_STATE_CLEAN: | |
e631ddba FH |
161 | /* Full (or almost full) of clean data. Clean list */ |
162 | list_add(&jeb->list, &c->clean_list); | |
1da177e4 LT |
163 | break; |
164 | ||
165 | case BLK_STATE_PARTDIRTY: | |
e631ddba FH |
166 | /* Some data, but not full. Dirty list. */ |
167 | /* We want to remember the block with most free space | |
168 | and stick it in the 'nextblock' position to start writing to it. */ | |
169 | if (jeb->free_size > min_free(c) && | |
170 | (!c->nextblock || c->nextblock->free_size < jeb->free_size)) { | |
171 | /* Better candidate for the next writes to go to */ | |
172 | if (c->nextblock) { | |
1da177e4 LT |
173 | c->nextblock->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size; |
174 | c->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size; | |
175 | c->free_size -= c->nextblock->free_size; | |
176 | c->wasted_size -= c->nextblock->wasted_size; | |
177 | c->nextblock->free_size = c->nextblock->wasted_size = 0; | |
178 | if (VERYDIRTY(c, c->nextblock->dirty_size)) { | |
179 | list_add(&c->nextblock->list, &c->very_dirty_list); | |
180 | } else { | |
181 | list_add(&c->nextblock->list, &c->dirty_list); | |
182 | } | |
e631ddba FH |
183 | /* deleting summary information of the old nextblock */ |
184 | jffs2_sum_reset_collected(c->summary); | |
1da177e4 | 185 | } |
e631ddba FH |
186 | /* update collected summary infromation for the current nextblock */ |
187 | jffs2_sum_move_collected(c, s); | |
188 | D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset)); | |
189 | c->nextblock = jeb; | |
190 | } else { | |
1da177e4 LT |
191 | jeb->dirty_size += jeb->free_size + jeb->wasted_size; |
192 | c->dirty_size += jeb->free_size + jeb->wasted_size; | |
193 | c->free_size -= jeb->free_size; | |
194 | c->wasted_size -= jeb->wasted_size; | |
195 | jeb->free_size = jeb->wasted_size = 0; | |
196 | if (VERYDIRTY(c, jeb->dirty_size)) { | |
197 | list_add(&jeb->list, &c->very_dirty_list); | |
198 | } else { | |
199 | list_add(&jeb->list, &c->dirty_list); | |
200 | } | |
e631ddba | 201 | } |
1da177e4 LT |
202 | break; |
203 | ||
204 | case BLK_STATE_ALLDIRTY: | |
205 | /* Nothing valid - not even a clean marker. Needs erasing. */ | |
e631ddba | 206 | /* For now we just put it on the erasing list. We'll start the erases later */ |
1da177e4 | 207 | D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset)); |
e631ddba | 208 | list_add(&jeb->list, &c->erase_pending_list); |
1da177e4 LT |
209 | c->nr_erasing_blocks++; |
210 | break; | |
e631ddba | 211 | |
1da177e4 LT |
212 | case BLK_STATE_BADBLOCK: |
213 | D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset)); | |
e631ddba | 214 | list_add(&jeb->list, &c->bad_list); |
1da177e4 LT |
215 | c->bad_size += c->sector_size; |
216 | c->free_size -= c->sector_size; | |
217 | bad_blocks++; | |
218 | break; | |
219 | default: | |
220 | printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n"); | |
e631ddba | 221 | BUG(); |
1da177e4 LT |
222 | } |
223 | } | |
e631ddba | 224 | |
1da177e4 LT |
225 | /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */ |
226 | if (c->nextblock && (c->nextblock->dirty_size)) { | |
227 | c->nextblock->wasted_size += c->nextblock->dirty_size; | |
228 | c->wasted_size += c->nextblock->dirty_size; | |
229 | c->dirty_size -= c->nextblock->dirty_size; | |
230 | c->nextblock->dirty_size = 0; | |
231 | } | |
2f82ce1e | 232 | #ifdef CONFIG_JFFS2_FS_WRITEBUFFER |
e96fb230 | 233 | if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) { |
182ec4ee | 234 | /* If we're going to start writing into a block which already |
1da177e4 LT |
235 | contains data, and the end of the data isn't page-aligned, |
236 | skip a little and align it. */ | |
237 | ||
daba5cc4 | 238 | uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize; |
1da177e4 LT |
239 | |
240 | D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n", | |
241 | skip)); | |
242 | c->nextblock->wasted_size += skip; | |
243 | c->wasted_size += skip; | |
244 | ||
245 | c->nextblock->free_size -= skip; | |
246 | c->free_size -= skip; | |
247 | } | |
248 | #endif | |
249 | if (c->nr_erasing_blocks) { | |
182ec4ee | 250 | if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) { |
1da177e4 LT |
251 | printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n"); |
252 | printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks); | |
253 | ret = -EIO; | |
254 | goto out; | |
255 | } | |
256 | jffs2_erase_pending_trigger(c); | |
257 | } | |
258 | ret = 0; | |
259 | out: | |
260 | if (buf_size) | |
261 | kfree(flashbuf); | |
262 | #ifndef __ECOS | |
182ec4ee | 263 | else |
1da177e4 LT |
264 | c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size); |
265 | #endif | |
5b5ffbc1 FM |
266 | if (s) |
267 | kfree(s); | |
268 | ||
1da177e4 LT |
269 | return ret; |
270 | } | |
271 | ||
e631ddba | 272 | int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf, |
1da177e4 LT |
273 | uint32_t ofs, uint32_t len) |
274 | { | |
275 | int ret; | |
276 | size_t retlen; | |
277 | ||
278 | ret = jffs2_flash_read(c, ofs, len, &retlen, buf); | |
279 | if (ret) { | |
280 | D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret)); | |
281 | return ret; | |
282 | } | |
283 | if (retlen < len) { | |
284 | D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen)); | |
285 | return -EIO; | |
286 | } | |
1da177e4 LT |
287 | return 0; |
288 | } | |
289 | ||
e631ddba FH |
290 | int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) |
291 | { | |
292 | if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size | |
293 | && (!jeb->first_node || !jeb->first_node->next_phys) ) | |
294 | return BLK_STATE_CLEANMARKER; | |
295 | ||
296 | /* move blocks with max 4 byte dirty space to cleanlist */ | |
297 | else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) { | |
298 | c->dirty_size -= jeb->dirty_size; | |
299 | c->wasted_size += jeb->dirty_size; | |
300 | jeb->wasted_size += jeb->dirty_size; | |
301 | jeb->dirty_size = 0; | |
302 | return BLK_STATE_CLEAN; | |
303 | } else if (jeb->used_size || jeb->unchecked_size) | |
304 | return BLK_STATE_PARTDIRTY; | |
305 | else | |
306 | return BLK_STATE_ALLDIRTY; | |
307 | } | |
308 | ||
1da177e4 | 309 | static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, |
e631ddba | 310 | unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) { |
1da177e4 LT |
311 | struct jffs2_unknown_node *node; |
312 | struct jffs2_unknown_node crcnode; | |
e631ddba | 313 | struct jffs2_sum_marker *sm; |
1da177e4 LT |
314 | uint32_t ofs, prevofs; |
315 | uint32_t hdr_crc, buf_ofs, buf_len; | |
316 | int err; | |
317 | int noise = 0; | |
e631ddba FH |
318 | |
319 | ||
2f82ce1e | 320 | #ifdef CONFIG_JFFS2_FS_WRITEBUFFER |
1da177e4 LT |
321 | int cleanmarkerfound = 0; |
322 | #endif | |
323 | ||
324 | ofs = jeb->offset; | |
325 | prevofs = jeb->offset - 1; | |
326 | ||
327 | D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs)); | |
328 | ||
2f82ce1e | 329 | #ifdef CONFIG_JFFS2_FS_WRITEBUFFER |
1da177e4 LT |
330 | if (jffs2_cleanmarker_oob(c)) { |
331 | int ret = jffs2_check_nand_cleanmarker(c, jeb); | |
332 | D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret)); | |
333 | /* Even if it's not found, we still scan to see | |
334 | if the block is empty. We use this information | |
335 | to decide whether to erase it or not. */ | |
336 | switch (ret) { | |
337 | case 0: cleanmarkerfound = 1; break; | |
338 | case 1: break; | |
339 | case 2: return BLK_STATE_BADBLOCK; | |
340 | case 3: return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */ | |
341 | default: return ret; | |
342 | } | |
343 | } | |
344 | #endif | |
e631ddba FH |
345 | |
346 | if (jffs2_sum_active()) { | |
347 | sm = kmalloc(sizeof(struct jffs2_sum_marker), GFP_KERNEL); | |
348 | if (!sm) { | |
349 | return -ENOMEM; | |
350 | } | |
351 | ||
352 | err = jffs2_fill_scan_buf(c, (unsigned char *) sm, jeb->offset + c->sector_size - | |
353 | sizeof(struct jffs2_sum_marker), sizeof(struct jffs2_sum_marker)); | |
354 | if (err) { | |
355 | kfree(sm); | |
356 | return err; | |
357 | } | |
358 | ||
359 | if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC ) { | |
360 | err = jffs2_sum_scan_sumnode(c, jeb, je32_to_cpu(sm->offset), &pseudo_random); | |
361 | if (err) { | |
362 | kfree(sm); | |
363 | return err; | |
364 | } | |
365 | } | |
366 | ||
367 | kfree(sm); | |
e631ddba FH |
368 | } |
369 | ||
1da177e4 LT |
370 | buf_ofs = jeb->offset; |
371 | ||
372 | if (!buf_size) { | |
373 | buf_len = c->sector_size; | |
374 | } else { | |
3be36675 | 375 | buf_len = EMPTY_SCAN_SIZE(c->sector_size); |
1da177e4 LT |
376 | err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len); |
377 | if (err) | |
378 | return err; | |
379 | } | |
182ec4ee | 380 | |
1da177e4 LT |
381 | /* We temporarily use 'ofs' as a pointer into the buffer/jeb */ |
382 | ofs = 0; | |
383 | ||
384 | /* Scan only 4KiB of 0xFF before declaring it's empty */ | |
3be36675 | 385 | while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF) |
1da177e4 LT |
386 | ofs += 4; |
387 | ||
3be36675 | 388 | if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) { |
2f82ce1e | 389 | #ifdef CONFIG_JFFS2_FS_WRITEBUFFER |
1da177e4 LT |
390 | if (jffs2_cleanmarker_oob(c)) { |
391 | /* scan oob, take care of cleanmarker */ | |
392 | int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound); | |
393 | D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret)); | |
394 | switch (ret) { | |
395 | case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF; | |
396 | case 1: return BLK_STATE_ALLDIRTY; | |
397 | default: return ret; | |
398 | } | |
399 | } | |
400 | #endif | |
401 | D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset)); | |
8f15fd55 AV |
402 | if (c->cleanmarker_size == 0) |
403 | return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */ | |
404 | else | |
405 | return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */ | |
1da177e4 LT |
406 | } |
407 | if (ofs) { | |
408 | D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset, | |
409 | jeb->offset + ofs)); | |
410 | DIRTY_SPACE(ofs); | |
411 | } | |
412 | ||
413 | /* Now ofs is a complete physical flash offset as it always was... */ | |
414 | ofs += jeb->offset; | |
415 | ||
416 | noise = 10; | |
417 | ||
733802d9 | 418 | dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset); |
e631ddba | 419 | |
182ec4ee | 420 | scan_more: |
1da177e4 LT |
421 | while(ofs < jeb->offset + c->sector_size) { |
422 | ||
e0c8e42f | 423 | jffs2_dbg_acct_paranoia_check_nolock(c, jeb); |
1da177e4 LT |
424 | |
425 | cond_resched(); | |
426 | ||
427 | if (ofs & 3) { | |
428 | printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs); | |
429 | ofs = PAD(ofs); | |
430 | continue; | |
431 | } | |
432 | if (ofs == prevofs) { | |
433 | printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs); | |
434 | DIRTY_SPACE(4); | |
435 | ofs += 4; | |
436 | continue; | |
437 | } | |
438 | prevofs = ofs; | |
439 | ||
440 | if (jeb->offset + c->sector_size < ofs + sizeof(*node)) { | |
441 | D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node), | |
442 | jeb->offset, c->sector_size, ofs, sizeof(*node))); | |
443 | DIRTY_SPACE((jeb->offset + c->sector_size)-ofs); | |
444 | break; | |
445 | } | |
446 | ||
447 | if (buf_ofs + buf_len < ofs + sizeof(*node)) { | |
448 | buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); | |
449 | D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n", | |
450 | sizeof(struct jffs2_unknown_node), buf_len, ofs)); | |
451 | err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); | |
452 | if (err) | |
453 | return err; | |
454 | buf_ofs = ofs; | |
455 | } | |
456 | ||
457 | node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs]; | |
458 | ||
459 | if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) { | |
460 | uint32_t inbuf_ofs; | |
461 | uint32_t empty_start; | |
462 | ||
463 | empty_start = ofs; | |
464 | ofs += 4; | |
465 | ||
466 | D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs)); | |
467 | more_empty: | |
468 | inbuf_ofs = ofs - buf_ofs; | |
469 | while (inbuf_ofs < buf_len) { | |
470 | if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) { | |
471 | printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n", | |
472 | empty_start, ofs); | |
473 | DIRTY_SPACE(ofs-empty_start); | |
474 | goto scan_more; | |
475 | } | |
476 | ||
477 | inbuf_ofs+=4; | |
478 | ofs += 4; | |
479 | } | |
480 | /* Ran off end. */ | |
481 | D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs)); | |
482 | ||
483 | /* If we're only checking the beginning of a block with a cleanmarker, | |
484 | bail now */ | |
182ec4ee | 485 | if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) && |
b81226c5 | 486 | c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) { |
3be36675 | 487 | D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size))); |
1da177e4 LT |
488 | return BLK_STATE_CLEANMARKER; |
489 | } | |
490 | ||
491 | /* See how much more there is to read in this eraseblock... */ | |
492 | buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); | |
493 | if (!buf_len) { | |
182ec4ee | 494 | /* No more to read. Break out of main loop without marking |
1da177e4 LT |
495 | this range of empty space as dirty (because it's not) */ |
496 | D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n", | |
497 | empty_start)); | |
498 | break; | |
499 | } | |
500 | D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs)); | |
501 | err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); | |
502 | if (err) | |
503 | return err; | |
504 | buf_ofs = ofs; | |
505 | goto more_empty; | |
506 | } | |
507 | ||
508 | if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) { | |
509 | printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs); | |
510 | DIRTY_SPACE(4); | |
511 | ofs += 4; | |
512 | continue; | |
513 | } | |
514 | if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) { | |
515 | D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs)); | |
516 | DIRTY_SPACE(4); | |
517 | ofs += 4; | |
518 | continue; | |
519 | } | |
520 | if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) { | |
521 | printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs); | |
522 | printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n"); | |
523 | DIRTY_SPACE(4); | |
524 | ofs += 4; | |
525 | continue; | |
526 | } | |
527 | if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) { | |
528 | /* OK. We're out of possibilities. Whinge and move on */ | |
182ec4ee TG |
529 | noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n", |
530 | JFFS2_MAGIC_BITMASK, ofs, | |
1da177e4 LT |
531 | je16_to_cpu(node->magic)); |
532 | DIRTY_SPACE(4); | |
533 | ofs += 4; | |
534 | continue; | |
535 | } | |
536 | /* We seem to have a node of sorts. Check the CRC */ | |
537 | crcnode.magic = node->magic; | |
538 | crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE); | |
539 | crcnode.totlen = node->totlen; | |
540 | hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4); | |
541 | ||
542 | if (hdr_crc != je32_to_cpu(node->hdr_crc)) { | |
543 | noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n", | |
544 | ofs, je16_to_cpu(node->magic), | |
182ec4ee | 545 | je16_to_cpu(node->nodetype), |
1da177e4 LT |
546 | je32_to_cpu(node->totlen), |
547 | je32_to_cpu(node->hdr_crc), | |
548 | hdr_crc); | |
549 | DIRTY_SPACE(4); | |
550 | ofs += 4; | |
551 | continue; | |
552 | } | |
553 | ||
182ec4ee | 554 | if (ofs + je32_to_cpu(node->totlen) > |
1da177e4 LT |
555 | jeb->offset + c->sector_size) { |
556 | /* Eep. Node goes over the end of the erase block. */ | |
557 | printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n", | |
558 | ofs, je32_to_cpu(node->totlen)); | |
559 | printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n"); | |
560 | DIRTY_SPACE(4); | |
561 | ofs += 4; | |
562 | continue; | |
563 | } | |
564 | ||
565 | if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) { | |
566 | /* Wheee. This is an obsoleted node */ | |
567 | D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs)); | |
568 | DIRTY_SPACE(PAD(je32_to_cpu(node->totlen))); | |
569 | ofs += PAD(je32_to_cpu(node->totlen)); | |
570 | continue; | |
571 | } | |
572 | ||
573 | switch(je16_to_cpu(node->nodetype)) { | |
574 | case JFFS2_NODETYPE_INODE: | |
575 | if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) { | |
576 | buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); | |
577 | D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n", | |
578 | sizeof(struct jffs2_raw_inode), buf_len, ofs)); | |
579 | err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); | |
580 | if (err) | |
581 | return err; | |
582 | buf_ofs = ofs; | |
583 | node = (void *)buf; | |
584 | } | |
e631ddba | 585 | err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s); |
1da177e4 LT |
586 | if (err) return err; |
587 | ofs += PAD(je32_to_cpu(node->totlen)); | |
588 | break; | |
182ec4ee | 589 | |
1da177e4 LT |
590 | case JFFS2_NODETYPE_DIRENT: |
591 | if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) { | |
592 | buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs); | |
593 | D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n", | |
594 | je32_to_cpu(node->totlen), buf_len, ofs)); | |
595 | err = jffs2_fill_scan_buf(c, buf, ofs, buf_len); | |
596 | if (err) | |
597 | return err; | |
598 | buf_ofs = ofs; | |
599 | node = (void *)buf; | |
600 | } | |
e631ddba | 601 | err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s); |
1da177e4 LT |
602 | if (err) return err; |
603 | ofs += PAD(je32_to_cpu(node->totlen)); | |
604 | break; | |
605 | ||
606 | case JFFS2_NODETYPE_CLEANMARKER: | |
607 | D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs)); | |
608 | if (je32_to_cpu(node->totlen) != c->cleanmarker_size) { | |
182ec4ee | 609 | printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n", |
1da177e4 LT |
610 | ofs, je32_to_cpu(node->totlen), c->cleanmarker_size); |
611 | DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node))); | |
612 | ofs += PAD(sizeof(struct jffs2_unknown_node)); | |
613 | } else if (jeb->first_node) { | |
614 | printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset); | |
615 | DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node))); | |
616 | ofs += PAD(sizeof(struct jffs2_unknown_node)); | |
617 | } else { | |
618 | struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref(); | |
619 | if (!marker_ref) { | |
620 | printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n"); | |
621 | return -ENOMEM; | |
622 | } | |
623 | marker_ref->next_in_ino = NULL; | |
624 | marker_ref->next_phys = NULL; | |
625 | marker_ref->flash_offset = ofs | REF_NORMAL; | |
626 | marker_ref->__totlen = c->cleanmarker_size; | |
627 | jeb->first_node = jeb->last_node = marker_ref; | |
182ec4ee | 628 | |
1da177e4 LT |
629 | USED_SPACE(PAD(c->cleanmarker_size)); |
630 | ofs += PAD(c->cleanmarker_size); | |
631 | } | |
632 | break; | |
633 | ||
634 | case JFFS2_NODETYPE_PADDING: | |
e631ddba FH |
635 | if (jffs2_sum_active()) |
636 | jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen)); | |
1da177e4 LT |
637 | DIRTY_SPACE(PAD(je32_to_cpu(node->totlen))); |
638 | ofs += PAD(je32_to_cpu(node->totlen)); | |
639 | break; | |
640 | ||
641 | default: | |
642 | switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) { | |
643 | case JFFS2_FEATURE_ROCOMPAT: | |
644 | printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); | |
645 | c->flags |= JFFS2_SB_FLAG_RO; | |
646 | if (!(jffs2_is_readonly(c))) | |
647 | return -EROFS; | |
648 | DIRTY_SPACE(PAD(je32_to_cpu(node->totlen))); | |
649 | ofs += PAD(je32_to_cpu(node->totlen)); | |
650 | break; | |
651 | ||
652 | case JFFS2_FEATURE_INCOMPAT: | |
653 | printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs); | |
654 | return -EINVAL; | |
655 | ||
656 | case JFFS2_FEATURE_RWCOMPAT_DELETE: | |
657 | D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); | |
658 | DIRTY_SPACE(PAD(je32_to_cpu(node->totlen))); | |
659 | ofs += PAD(je32_to_cpu(node->totlen)); | |
660 | break; | |
661 | ||
662 | case JFFS2_FEATURE_RWCOMPAT_COPY: | |
663 | D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs)); | |
664 | USED_SPACE(PAD(je32_to_cpu(node->totlen))); | |
665 | ofs += PAD(je32_to_cpu(node->totlen)); | |
666 | break; | |
667 | } | |
668 | } | |
669 | } | |
670 | ||
e631ddba FH |
671 | if (jffs2_sum_active()) { |
672 | if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) { | |
733802d9 | 673 | dbg_summary("There is not enough space for " |
e631ddba FH |
674 | "summary information, disabling for this jeb!\n"); |
675 | jffs2_sum_disable_collecting(s); | |
676 | } | |
677 | } | |
1da177e4 | 678 | |
182ec4ee | 679 | D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x\n", jeb->offset, |
1da177e4 LT |
680 | jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size)); |
681 | ||
682 | /* mark_node_obsolete can add to wasted !! */ | |
683 | if (jeb->wasted_size) { | |
684 | jeb->dirty_size += jeb->wasted_size; | |
685 | c->dirty_size += jeb->wasted_size; | |
686 | c->wasted_size -= jeb->wasted_size; | |
687 | jeb->wasted_size = 0; | |
688 | } | |
689 | ||
e631ddba | 690 | return jffs2_scan_classify_jeb(c, jeb); |
1da177e4 LT |
691 | } |
692 | ||
e631ddba | 693 | struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino) |
1da177e4 LT |
694 | { |
695 | struct jffs2_inode_cache *ic; | |
696 | ||
697 | ic = jffs2_get_ino_cache(c, ino); | |
698 | if (ic) | |
699 | return ic; | |
700 | ||
701 | if (ino > c->highest_ino) | |
702 | c->highest_ino = ino; | |
703 | ||
704 | ic = jffs2_alloc_inode_cache(); | |
705 | if (!ic) { | |
706 | printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n"); | |
707 | return NULL; | |
708 | } | |
709 | memset(ic, 0, sizeof(*ic)); | |
710 | ||
711 | ic->ino = ino; | |
712 | ic->nodes = (void *)ic; | |
713 | jffs2_add_ino_cache(c, ic); | |
714 | if (ino == 1) | |
715 | ic->nlink = 1; | |
716 | return ic; | |
717 | } | |
718 | ||
182ec4ee | 719 | static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, |
e631ddba | 720 | struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s) |
1da177e4 LT |
721 | { |
722 | struct jffs2_raw_node_ref *raw; | |
723 | struct jffs2_inode_cache *ic; | |
724 | uint32_t ino = je32_to_cpu(ri->ino); | |
725 | ||
726 | D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs)); | |
727 | ||
728 | /* We do very little here now. Just check the ino# to which we should attribute | |
182ec4ee | 729 | this node; we can do all the CRC checking etc. later. There's a tradeoff here -- |
1da177e4 LT |
730 | we used to scan the flash once only, reading everything we want from it into |
731 | memory, then building all our in-core data structures and freeing the extra | |
732 | information. Now we allow the first part of the mount to complete a lot quicker, | |
182ec4ee | 733 | but we have to go _back_ to the flash in order to finish the CRC checking, etc. |
1da177e4 LT |
734 | Which means that the _full_ amount of time to get to proper write mode with GC |
735 | operational may actually be _longer_ than before. Sucks to be me. */ | |
736 | ||
737 | raw = jffs2_alloc_raw_node_ref(); | |
738 | if (!raw) { | |
739 | printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n"); | |
740 | return -ENOMEM; | |
741 | } | |
742 | ||
743 | ic = jffs2_get_ino_cache(c, ino); | |
744 | if (!ic) { | |
745 | /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the | |
746 | first node we found for this inode. Do a CRC check to protect against the former | |
747 | case */ | |
748 | uint32_t crc = crc32(0, ri, sizeof(*ri)-8); | |
749 | ||
750 | if (crc != je32_to_cpu(ri->node_crc)) { | |
751 | printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", | |
752 | ofs, je32_to_cpu(ri->node_crc), crc); | |
753 | /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ | |
754 | DIRTY_SPACE(PAD(je32_to_cpu(ri->totlen))); | |
755 | jffs2_free_raw_node_ref(raw); | |
756 | return 0; | |
757 | } | |
758 | ic = jffs2_scan_make_ino_cache(c, ino); | |
759 | if (!ic) { | |
760 | jffs2_free_raw_node_ref(raw); | |
761 | return -ENOMEM; | |
762 | } | |
763 | } | |
764 | ||
765 | /* Wheee. It worked */ | |
766 | ||
767 | raw->flash_offset = ofs | REF_UNCHECKED; | |
768 | raw->__totlen = PAD(je32_to_cpu(ri->totlen)); | |
769 | raw->next_phys = NULL; | |
770 | raw->next_in_ino = ic->nodes; | |
771 | ||
772 | ic->nodes = raw; | |
773 | if (!jeb->first_node) | |
774 | jeb->first_node = raw; | |
775 | if (jeb->last_node) | |
776 | jeb->last_node->next_phys = raw; | |
777 | jeb->last_node = raw; | |
778 | ||
182ec4ee | 779 | D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n", |
1da177e4 LT |
780 | je32_to_cpu(ri->ino), je32_to_cpu(ri->version), |
781 | je32_to_cpu(ri->offset), | |
782 | je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize))); | |
783 | ||
784 | pseudo_random += je32_to_cpu(ri->version); | |
785 | ||
786 | UNCHECKED_SPACE(PAD(je32_to_cpu(ri->totlen))); | |
e631ddba FH |
787 | |
788 | if (jffs2_sum_active()) { | |
789 | jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset); | |
790 | } | |
791 | ||
1da177e4 LT |
792 | return 0; |
793 | } | |
794 | ||
182ec4ee | 795 | static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, |
e631ddba | 796 | struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s) |
1da177e4 LT |
797 | { |
798 | struct jffs2_raw_node_ref *raw; | |
799 | struct jffs2_full_dirent *fd; | |
800 | struct jffs2_inode_cache *ic; | |
801 | uint32_t crc; | |
802 | ||
803 | D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs)); | |
804 | ||
805 | /* We don't get here unless the node is still valid, so we don't have to | |
806 | mask in the ACCURATE bit any more. */ | |
807 | crc = crc32(0, rd, sizeof(*rd)-8); | |
808 | ||
809 | if (crc != je32_to_cpu(rd->node_crc)) { | |
810 | printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", | |
811 | ofs, je32_to_cpu(rd->node_crc), crc); | |
812 | /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */ | |
813 | DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen))); | |
814 | return 0; | |
815 | } | |
816 | ||
817 | pseudo_random += je32_to_cpu(rd->version); | |
818 | ||
819 | fd = jffs2_alloc_full_dirent(rd->nsize+1); | |
820 | if (!fd) { | |
821 | return -ENOMEM; | |
822 | } | |
823 | memcpy(&fd->name, rd->name, rd->nsize); | |
824 | fd->name[rd->nsize] = 0; | |
825 | ||
826 | crc = crc32(0, fd->name, rd->nsize); | |
827 | if (crc != je32_to_cpu(rd->name_crc)) { | |
828 | printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", | |
182ec4ee | 829 | ofs, je32_to_cpu(rd->name_crc), crc); |
1da177e4 LT |
830 | D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino))); |
831 | jffs2_free_full_dirent(fd); | |
832 | /* FIXME: Why do we believe totlen? */ | |
833 | /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */ | |
834 | DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen))); | |
835 | return 0; | |
836 | } | |
837 | raw = jffs2_alloc_raw_node_ref(); | |
838 | if (!raw) { | |
839 | jffs2_free_full_dirent(fd); | |
840 | printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n"); | |
841 | return -ENOMEM; | |
842 | } | |
843 | ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino)); | |
844 | if (!ic) { | |
845 | jffs2_free_full_dirent(fd); | |
846 | jffs2_free_raw_node_ref(raw); | |
847 | return -ENOMEM; | |
848 | } | |
182ec4ee | 849 | |
1da177e4 LT |
850 | raw->__totlen = PAD(je32_to_cpu(rd->totlen)); |
851 | raw->flash_offset = ofs | REF_PRISTINE; | |
852 | raw->next_phys = NULL; | |
853 | raw->next_in_ino = ic->nodes; | |
854 | ic->nodes = raw; | |
855 | if (!jeb->first_node) | |
856 | jeb->first_node = raw; | |
857 | if (jeb->last_node) | |
858 | jeb->last_node->next_phys = raw; | |
859 | jeb->last_node = raw; | |
860 | ||
861 | fd->raw = raw; | |
862 | fd->next = NULL; | |
863 | fd->version = je32_to_cpu(rd->version); | |
864 | fd->ino = je32_to_cpu(rd->ino); | |
865 | fd->nhash = full_name_hash(fd->name, rd->nsize); | |
866 | fd->type = rd->type; | |
867 | USED_SPACE(PAD(je32_to_cpu(rd->totlen))); | |
868 | jffs2_add_fd_to_list(c, fd, &ic->scan_dents); | |
869 | ||
e631ddba FH |
870 | if (jffs2_sum_active()) { |
871 | jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset); | |
872 | } | |
873 | ||
1da177e4 LT |
874 | return 0; |
875 | } | |
876 | ||
877 | static int count_list(struct list_head *l) | |
878 | { | |
879 | uint32_t count = 0; | |
880 | struct list_head *tmp; | |
881 | ||
882 | list_for_each(tmp, l) { | |
883 | count++; | |
884 | } | |
885 | return count; | |
886 | } | |
887 | ||
888 | /* Note: This breaks if list_empty(head). I don't care. You | |
889 | might, if you copy this code and use it elsewhere :) */ | |
890 | static void rotate_list(struct list_head *head, uint32_t count) | |
891 | { | |
892 | struct list_head *n = head->next; | |
893 | ||
894 | list_del(head); | |
895 | while(count--) { | |
896 | n = n->next; | |
897 | } | |
898 | list_add(head, n); | |
899 | } | |
900 | ||
901 | void jffs2_rotate_lists(struct jffs2_sb_info *c) | |
902 | { | |
903 | uint32_t x; | |
904 | uint32_t rotateby; | |
905 | ||
906 | x = count_list(&c->clean_list); | |
907 | if (x) { | |
908 | rotateby = pseudo_random % x; | |
1da177e4 | 909 | rotate_list((&c->clean_list), rotateby); |
1da177e4 LT |
910 | } |
911 | ||
912 | x = count_list(&c->very_dirty_list); | |
913 | if (x) { | |
914 | rotateby = pseudo_random % x; | |
1da177e4 | 915 | rotate_list((&c->very_dirty_list), rotateby); |
1da177e4 LT |
916 | } |
917 | ||
918 | x = count_list(&c->dirty_list); | |
919 | if (x) { | |
920 | rotateby = pseudo_random % x; | |
1da177e4 | 921 | rotate_list((&c->dirty_list), rotateby); |
1da177e4 LT |
922 | } |
923 | ||
924 | x = count_list(&c->erasable_list); | |
925 | if (x) { | |
926 | rotateby = pseudo_random % x; | |
1da177e4 | 927 | rotate_list((&c->erasable_list), rotateby); |
1da177e4 LT |
928 | } |
929 | ||
930 | if (c->nr_erasing_blocks) { | |
931 | rotateby = pseudo_random % c->nr_erasing_blocks; | |
1da177e4 | 932 | rotate_list((&c->erase_pending_list), rotateby); |
1da177e4 LT |
933 | } |
934 | ||
935 | if (c->nr_free_blocks) { | |
936 | rotateby = pseudo_random % c->nr_free_blocks; | |
1da177e4 | 937 | rotate_list((&c->free_list), rotateby); |
1da177e4 LT |
938 | } |
939 | } |