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1da177e4 LT |
1 | /* |
2 | * JFFS -- Journaling Flash File System, Linux implementation. | |
3 | * | |
4 | * Copyright (C) 1999, 2000 Axis Communications AB. | |
5 | * | |
6 | * Created by Finn Hakansson <finn@axis.com>. | |
7 | * | |
8 | * This is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * $Id: jffs_fm.c,v 1.27 2001/09/20 12:29:47 dwmw2 Exp $ | |
14 | * | |
15 | * Ported to Linux 2.3.x and MTD: | |
16 | * Copyright (C) 2000 Alexander Larsson (alex@cendio.se), Cendio Systems AB | |
17 | * | |
18 | */ | |
19 | #include <linux/slab.h> | |
20 | #include <linux/blkdev.h> | |
21 | #include <linux/jffs.h> | |
22 | #include "jffs_fm.h" | |
23 | ||
24 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE | |
25 | static int jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset); | |
26 | #endif | |
27 | ||
28 | static struct jffs_fm *jffs_alloc_fm(void); | |
29 | static void jffs_free_fm(struct jffs_fm *n); | |
30 | ||
31 | extern kmem_cache_t *fm_cache; | |
32 | extern kmem_cache_t *node_cache; | |
33 | ||
34 | /* This function creates a new shiny flash memory control structure. */ | |
35 | struct jffs_fmcontrol * | |
36 | jffs_build_begin(struct jffs_control *c, int unit) | |
37 | { | |
38 | struct jffs_fmcontrol *fmc; | |
39 | struct mtd_info *mtd; | |
40 | ||
41 | D3(printk("jffs_build_begin()\n")); | |
42 | fmc = (struct jffs_fmcontrol *)kmalloc(sizeof(struct jffs_fmcontrol), | |
43 | GFP_KERNEL); | |
44 | if (!fmc) { | |
45 | D(printk("jffs_build_begin(): Allocation of " | |
46 | "struct jffs_fmcontrol failed!\n")); | |
47 | return (struct jffs_fmcontrol *)0; | |
48 | } | |
49 | DJM(no_jffs_fmcontrol++); | |
50 | ||
51 | mtd = get_mtd_device(NULL, unit); | |
52 | ||
53 | if (!mtd) { | |
54 | kfree(fmc); | |
55 | DJM(no_jffs_fmcontrol--); | |
56 | return NULL; | |
57 | } | |
58 | ||
59 | /* Retrieve the size of the flash memory. */ | |
60 | fmc->flash_size = mtd->size; | |
61 | D3(printk(" fmc->flash_size = %d bytes\n", fmc->flash_size)); | |
62 | ||
63 | fmc->used_size = 0; | |
64 | fmc->dirty_size = 0; | |
65 | fmc->free_size = mtd->size; | |
66 | fmc->sector_size = mtd->erasesize; | |
67 | fmc->max_chunk_size = fmc->sector_size >> 1; | |
68 | /* min_free_size: | |
69 | 1 sector, obviously. | |
70 | + 1 x max_chunk_size, for when a nodes overlaps the end of a sector | |
71 | + 1 x max_chunk_size again, which ought to be enough to handle | |
72 | the case where a rename causes a name to grow, and GC has | |
73 | to write out larger nodes than the ones it's obsoleting. | |
74 | We should fix it so it doesn't have to write the name | |
75 | _every_ time. Later. | |
76 | + another 2 sectors because people keep getting GC stuck and | |
77 | we don't know why. This scares me - I want formal proof | |
78 | of correctness of whatever number we put here. dwmw2. | |
79 | */ | |
80 | fmc->min_free_size = fmc->sector_size << 2; | |
81 | fmc->mtd = mtd; | |
82 | fmc->c = c; | |
83 | fmc->head = NULL; | |
84 | fmc->tail = NULL; | |
85 | fmc->head_extra = NULL; | |
86 | fmc->tail_extra = NULL; | |
87 | init_MUTEX(&fmc->biglock); | |
88 | return fmc; | |
89 | } | |
90 | ||
91 | ||
92 | /* When the flash memory scan has completed, this function should be called | |
93 | before use of the control structure. */ | |
94 | void | |
95 | jffs_build_end(struct jffs_fmcontrol *fmc) | |
96 | { | |
97 | D3(printk("jffs_build_end()\n")); | |
98 | ||
99 | if (!fmc->head) { | |
100 | fmc->head = fmc->head_extra; | |
101 | fmc->tail = fmc->tail_extra; | |
102 | } | |
103 | else if (fmc->head_extra) { | |
104 | fmc->tail_extra->next = fmc->head; | |
105 | fmc->head->prev = fmc->tail_extra; | |
106 | fmc->head = fmc->head_extra; | |
107 | } | |
108 | fmc->head_extra = NULL; /* These two instructions should be omitted. */ | |
109 | fmc->tail_extra = NULL; | |
110 | D3(jffs_print_fmcontrol(fmc)); | |
111 | } | |
112 | ||
113 | ||
114 | /* Call this function when the file system is unmounted. This function | |
115 | frees all memory used by this module. */ | |
116 | void | |
117 | jffs_cleanup_fmcontrol(struct jffs_fmcontrol *fmc) | |
118 | { | |
119 | if (fmc) { | |
120 | struct jffs_fm *next = fmc->head; | |
121 | while (next) { | |
122 | struct jffs_fm *cur = next; | |
123 | next = next->next; | |
124 | jffs_free_fm(cur); | |
125 | } | |
126 | put_mtd_device(fmc->mtd); | |
127 | kfree(fmc); | |
128 | DJM(no_jffs_fmcontrol--); | |
129 | } | |
130 | } | |
131 | ||
132 | ||
133 | /* This function returns the size of the first chunk of free space on the | |
134 | flash memory. This function will return something nonzero if the flash | |
135 | memory contains any free space. */ | |
136 | __u32 | |
137 | jffs_free_size1(struct jffs_fmcontrol *fmc) | |
138 | { | |
139 | __u32 head; | |
140 | __u32 tail; | |
141 | __u32 end = fmc->flash_size; | |
142 | ||
143 | if (!fmc->head) { | |
144 | /* There is nothing on the flash. */ | |
145 | return fmc->flash_size; | |
146 | } | |
147 | ||
148 | /* Compute the beginning and ending of the contents of the flash. */ | |
149 | head = fmc->head->offset; | |
150 | tail = fmc->tail->offset + fmc->tail->size; | |
151 | if (tail == end) { | |
152 | tail = 0; | |
153 | } | |
154 | ASSERT(else if (tail > end) { | |
155 | printk(KERN_WARNING "jffs_free_size1(): tail > end\n"); | |
156 | tail = 0; | |
157 | }); | |
158 | ||
159 | if (head <= tail) { | |
160 | return end - tail; | |
161 | } | |
162 | else { | |
163 | return head - tail; | |
164 | } | |
165 | } | |
166 | ||
167 | /* This function will return something nonzero in case there are two free | |
168 | areas on the flash. Like this: | |
169 | ||
170 | +----------------+------------------+----------------+ | |
171 | | FREE 1 | USED / DIRTY | FREE 2 | | |
172 | +----------------+------------------+----------------+ | |
173 | fmc->head -----^ | |
174 | fmc->tail ------------------------^ | |
175 | ||
176 | The value returned, will be the size of the first empty area on the | |
177 | flash, in this case marked "FREE 1". */ | |
178 | __u32 | |
179 | jffs_free_size2(struct jffs_fmcontrol *fmc) | |
180 | { | |
181 | if (fmc->head) { | |
182 | __u32 head = fmc->head->offset; | |
183 | __u32 tail = fmc->tail->offset + fmc->tail->size; | |
184 | if (tail == fmc->flash_size) { | |
185 | tail = 0; | |
186 | } | |
187 | ||
188 | if (tail >= head) { | |
189 | return head; | |
190 | } | |
191 | } | |
192 | return 0; | |
193 | } | |
194 | ||
195 | ||
196 | /* Allocate a chunk of flash memory. If there is enough space on the | |
197 | device, a reference to the associated node is stored in the jffs_fm | |
198 | struct. */ | |
199 | int | |
200 | jffs_fmalloc(struct jffs_fmcontrol *fmc, __u32 size, struct jffs_node *node, | |
201 | struct jffs_fm **result) | |
202 | { | |
203 | struct jffs_fm *fm; | |
204 | __u32 free_chunk_size1; | |
205 | __u32 free_chunk_size2; | |
206 | ||
207 | D2(printk("jffs_fmalloc(): fmc = 0x%p, size = %d, " | |
208 | "node = 0x%p\n", fmc, size, node)); | |
209 | ||
210 | *result = NULL; | |
211 | ||
212 | if (!(fm = jffs_alloc_fm())) { | |
213 | D(printk("jffs_fmalloc(): kmalloc() failed! (fm)\n")); | |
214 | return -ENOMEM; | |
215 | } | |
216 | ||
217 | free_chunk_size1 = jffs_free_size1(fmc); | |
218 | free_chunk_size2 = jffs_free_size2(fmc); | |
219 | if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) { | |
220 | printk(KERN_WARNING "Free size accounting screwed\n"); | |
221 | printk(KERN_WARNING "free_chunk_size1 == 0x%x, free_chunk_size2 == 0x%x, fmc->free_size == 0x%x\n", free_chunk_size1, free_chunk_size2, fmc->free_size); | |
222 | } | |
223 | ||
224 | D3(printk("jffs_fmalloc(): free_chunk_size1 = %u, " | |
225 | "free_chunk_size2 = %u\n", | |
226 | free_chunk_size1, free_chunk_size2)); | |
227 | ||
228 | if (size <= free_chunk_size1) { | |
229 | if (!(fm->nodes = (struct jffs_node_ref *) | |
230 | kmalloc(sizeof(struct jffs_node_ref), | |
231 | GFP_KERNEL))) { | |
232 | D(printk("jffs_fmalloc(): kmalloc() failed! " | |
233 | "(node_ref)\n")); | |
234 | jffs_free_fm(fm); | |
235 | return -ENOMEM; | |
236 | } | |
237 | DJM(no_jffs_node_ref++); | |
238 | fm->nodes->node = node; | |
239 | fm->nodes->next = NULL; | |
240 | if (fmc->tail) { | |
241 | fm->offset = fmc->tail->offset + fmc->tail->size; | |
242 | if (fm->offset == fmc->flash_size) { | |
243 | fm->offset = 0; | |
244 | } | |
245 | ASSERT(else if (fm->offset > fmc->flash_size) { | |
246 | printk(KERN_WARNING "jffs_fmalloc(): " | |
247 | "offset > flash_end\n"); | |
248 | fm->offset = 0; | |
249 | }); | |
250 | } | |
251 | else { | |
252 | /* There don't have to be files in the file | |
253 | system yet. */ | |
254 | fm->offset = 0; | |
255 | } | |
256 | fm->size = size; | |
257 | fmc->free_size -= size; | |
258 | fmc->used_size += size; | |
259 | } | |
260 | else if (size > free_chunk_size2) { | |
261 | printk(KERN_WARNING "JFFS: Tried to allocate a too " | |
262 | "large flash memory chunk. (size = %u)\n", size); | |
263 | jffs_free_fm(fm); | |
264 | return -ENOSPC; | |
265 | } | |
266 | else { | |
267 | fm->offset = fmc->tail->offset + fmc->tail->size; | |
268 | fm->size = free_chunk_size1; | |
269 | fm->nodes = NULL; | |
270 | fmc->free_size -= fm->size; | |
271 | fmc->dirty_size += fm->size; /* Changed by simonk. This seemingly fixes a | |
272 | bug that caused infinite garbage collection. | |
273 | It previously set fmc->dirty_size to size (which is the | |
274 | size of the requested chunk). | |
275 | */ | |
276 | } | |
277 | ||
278 | fm->next = NULL; | |
279 | if (!fmc->head) { | |
280 | fm->prev = NULL; | |
281 | fmc->head = fm; | |
282 | fmc->tail = fm; | |
283 | } | |
284 | else { | |
285 | fm->prev = fmc->tail; | |
286 | fmc->tail->next = fm; | |
287 | fmc->tail = fm; | |
288 | } | |
289 | ||
290 | D3(jffs_print_fmcontrol(fmc)); | |
291 | D3(jffs_print_fm(fm)); | |
292 | *result = fm; | |
293 | return 0; | |
294 | } | |
295 | ||
296 | ||
297 | /* The on-flash space is not needed anymore by the passed node. Remove | |
298 | the reference to the node from the node list. If the data chunk in | |
299 | the flash memory isn't used by any more nodes anymore (fm->nodes == 0), | |
300 | then mark that chunk as dirty. */ | |
301 | int | |
302 | jffs_fmfree(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, struct jffs_node *node) | |
303 | { | |
304 | struct jffs_node_ref *ref; | |
305 | struct jffs_node_ref *prev; | |
306 | ASSERT(int del = 0); | |
307 | ||
308 | D2(printk("jffs_fmfree(): node->ino = %u, node->version = %u\n", | |
309 | node->ino, node->version)); | |
310 | ||
311 | ASSERT(if (!fmc || !fm || !fm->nodes) { | |
312 | printk(KERN_ERR "jffs_fmfree(): fmc: 0x%p, fm: 0x%p, " | |
313 | "fm->nodes: 0x%p\n", | |
314 | fmc, fm, (fm ? fm->nodes : NULL)); | |
315 | return -1; | |
316 | }); | |
317 | ||
318 | /* Find the reference to the node that is going to be removed | |
319 | and remove it. */ | |
320 | for (ref = fm->nodes, prev = NULL; ref; ref = ref->next) { | |
321 | if (ref->node == node) { | |
322 | if (prev) { | |
323 | prev->next = ref->next; | |
324 | } | |
325 | else { | |
326 | fm->nodes = ref->next; | |
327 | } | |
328 | kfree(ref); | |
329 | DJM(no_jffs_node_ref--); | |
330 | ASSERT(del = 1); | |
331 | break; | |
332 | } | |
333 | prev = ref; | |
334 | } | |
335 | ||
336 | /* If the data chunk in the flash memory isn't used anymore | |
337 | just mark it as obsolete. */ | |
338 | if (!fm->nodes) { | |
339 | /* No node uses this chunk so let's remove it. */ | |
340 | fmc->used_size -= fm->size; | |
341 | fmc->dirty_size += fm->size; | |
342 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE | |
343 | if (jffs_mark_obsolete(fmc, fm->offset) < 0) { | |
344 | D1(printk("jffs_fmfree(): Failed to mark an on-flash " | |
345 | "node obsolete!\n")); | |
346 | return -1; | |
347 | } | |
348 | #endif | |
349 | } | |
350 | ||
351 | ASSERT(if (!del) { | |
352 | printk(KERN_WARNING "***jffs_fmfree(): " | |
353 | "Didn't delete any node reference!\n"); | |
354 | }); | |
355 | ||
356 | return 0; | |
357 | } | |
358 | ||
359 | ||
360 | /* This allocation function is used during the initialization of | |
361 | the file system. */ | |
362 | struct jffs_fm * | |
363 | jffs_fmalloced(struct jffs_fmcontrol *fmc, __u32 offset, __u32 size, | |
364 | struct jffs_node *node) | |
365 | { | |
366 | struct jffs_fm *fm; | |
367 | ||
368 | D3(printk("jffs_fmalloced()\n")); | |
369 | ||
370 | if (!(fm = jffs_alloc_fm())) { | |
371 | D(printk("jffs_fmalloced(0x%p, %u, %u, 0x%p): failed!\n", | |
372 | fmc, offset, size, node)); | |
373 | return NULL; | |
374 | } | |
375 | fm->offset = offset; | |
376 | fm->size = size; | |
377 | fm->prev = NULL; | |
378 | fm->next = NULL; | |
379 | fm->nodes = NULL; | |
380 | if (node) { | |
381 | /* `node' exists and it should be associated with the | |
382 | jffs_fm structure `fm'. */ | |
383 | if (!(fm->nodes = (struct jffs_node_ref *) | |
384 | kmalloc(sizeof(struct jffs_node_ref), | |
385 | GFP_KERNEL))) { | |
386 | D(printk("jffs_fmalloced(): !fm->nodes\n")); | |
387 | jffs_free_fm(fm); | |
388 | return NULL; | |
389 | } | |
390 | DJM(no_jffs_node_ref++); | |
391 | fm->nodes->node = node; | |
392 | fm->nodes->next = NULL; | |
393 | fmc->used_size += size; | |
394 | fmc->free_size -= size; | |
395 | } | |
396 | else { | |
397 | /* If there is no node, then this is just a chunk of dirt. */ | |
398 | fmc->dirty_size += size; | |
399 | fmc->free_size -= size; | |
400 | } | |
401 | ||
402 | if (fmc->head_extra) { | |
403 | fm->prev = fmc->tail_extra; | |
404 | fmc->tail_extra->next = fm; | |
405 | fmc->tail_extra = fm; | |
406 | } | |
407 | else if (!fmc->head) { | |
408 | fmc->head = fm; | |
409 | fmc->tail = fm; | |
410 | } | |
411 | else if (fmc->tail->offset + fmc->tail->size < offset) { | |
412 | fmc->head_extra = fm; | |
413 | fmc->tail_extra = fm; | |
414 | } | |
415 | else { | |
416 | fm->prev = fmc->tail; | |
417 | fmc->tail->next = fm; | |
418 | fmc->tail = fm; | |
419 | } | |
420 | D3(jffs_print_fmcontrol(fmc)); | |
421 | D3(jffs_print_fm(fm)); | |
422 | return fm; | |
423 | } | |
424 | ||
425 | ||
426 | /* Add a new node to an already existing jffs_fm struct. */ | |
427 | int | |
428 | jffs_add_node(struct jffs_node *node) | |
429 | { | |
430 | struct jffs_node_ref *ref; | |
431 | ||
432 | D3(printk("jffs_add_node(): ino = %u\n", node->ino)); | |
433 | ||
434 | ref = (struct jffs_node_ref *)kmalloc(sizeof(struct jffs_node_ref), | |
435 | GFP_KERNEL); | |
436 | if (!ref) | |
437 | return -ENOMEM; | |
438 | ||
439 | DJM(no_jffs_node_ref++); | |
440 | ref->node = node; | |
441 | ref->next = node->fm->nodes; | |
442 | node->fm->nodes = ref; | |
443 | return 0; | |
444 | } | |
445 | ||
446 | ||
447 | /* Free a part of some allocated space. */ | |
448 | void | |
449 | jffs_fmfree_partly(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, __u32 size) | |
450 | { | |
451 | D1(printk("***jffs_fmfree_partly(): fm = 0x%p, fm->nodes = 0x%p, " | |
452 | "fm->nodes->node->ino = %u, size = %u\n", | |
453 | fm, (fm ? fm->nodes : 0), | |
454 | (!fm ? 0 : (!fm->nodes ? 0 : fm->nodes->node->ino)), size)); | |
455 | ||
456 | if (fm->nodes) { | |
457 | kfree(fm->nodes); | |
458 | DJM(no_jffs_node_ref--); | |
459 | fm->nodes = NULL; | |
460 | } | |
461 | fmc->used_size -= fm->size; | |
462 | if (fm == fmc->tail) { | |
463 | fm->size -= size; | |
464 | fmc->free_size += size; | |
465 | } | |
466 | fmc->dirty_size += fm->size; | |
467 | } | |
468 | ||
469 | ||
470 | /* Find the jffs_fm struct that contains the end of the data chunk that | |
471 | begins at the logical beginning of the flash memory and spans `size' | |
472 | bytes. If we want to erase a sector of the flash memory, we use this | |
473 | function to find where the sector limit cuts a chunk of data. */ | |
474 | struct jffs_fm * | |
475 | jffs_cut_node(struct jffs_fmcontrol *fmc, __u32 size) | |
476 | { | |
477 | struct jffs_fm *fm; | |
478 | __u32 pos = 0; | |
479 | ||
480 | if (size == 0) { | |
481 | return NULL; | |
482 | } | |
483 | ||
484 | ASSERT(if (!fmc) { | |
485 | printk(KERN_ERR "jffs_cut_node(): fmc == NULL\n"); | |
486 | return NULL; | |
487 | }); | |
488 | ||
489 | fm = fmc->head; | |
490 | ||
491 | while (fm) { | |
492 | pos += fm->size; | |
493 | if (pos < size) { | |
494 | fm = fm->next; | |
495 | } | |
496 | else if (pos > size) { | |
497 | break; | |
498 | } | |
499 | else { | |
500 | fm = NULL; | |
501 | break; | |
502 | } | |
503 | } | |
504 | ||
505 | return fm; | |
506 | } | |
507 | ||
508 | ||
509 | /* Move the head of the fmc structures and delete the obsolete parts. */ | |
510 | void | |
511 | jffs_sync_erase(struct jffs_fmcontrol *fmc, int erased_size) | |
512 | { | |
513 | struct jffs_fm *fm; | |
514 | struct jffs_fm *del; | |
515 | ||
516 | ASSERT(if (!fmc) { | |
517 | printk(KERN_ERR "jffs_sync_erase(): fmc == NULL\n"); | |
518 | return; | |
519 | }); | |
520 | ||
521 | fmc->dirty_size -= erased_size; | |
522 | fmc->free_size += erased_size; | |
523 | ||
524 | for (fm = fmc->head; fm && (erased_size > 0);) { | |
525 | if (erased_size >= fm->size) { | |
526 | erased_size -= fm->size; | |
527 | del = fm; | |
528 | fm = fm->next; | |
529 | fm->prev = NULL; | |
530 | fmc->head = fm; | |
531 | jffs_free_fm(del); | |
532 | } | |
533 | else { | |
534 | fm->size -= erased_size; | |
535 | fm->offset += erased_size; | |
536 | break; | |
537 | } | |
538 | } | |
539 | } | |
540 | ||
541 | ||
542 | /* Return the oldest used node in the flash memory. */ | |
543 | struct jffs_node * | |
544 | jffs_get_oldest_node(struct jffs_fmcontrol *fmc) | |
545 | { | |
546 | struct jffs_fm *fm; | |
547 | struct jffs_node_ref *nref; | |
548 | struct jffs_node *node = NULL; | |
549 | ||
550 | ASSERT(if (!fmc) { | |
551 | printk(KERN_ERR "jffs_get_oldest_node(): fmc == NULL\n"); | |
552 | return NULL; | |
553 | }); | |
554 | ||
555 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next); | |
556 | ||
557 | if (!fm) { | |
558 | return NULL; | |
559 | } | |
560 | ||
561 | /* The oldest node is the last one in the reference list. This list | |
562 | shouldn't be too long; just one or perhaps two elements. */ | |
563 | for (nref = fm->nodes; nref; nref = nref->next) { | |
564 | node = nref->node; | |
565 | } | |
566 | ||
567 | D2(printk("jffs_get_oldest_node(): ino = %u, version = %u\n", | |
568 | (node ? node->ino : 0), (node ? node->version : 0))); | |
569 | ||
570 | return node; | |
571 | } | |
572 | ||
573 | ||
574 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE | |
575 | ||
576 | /* Mark an on-flash node as obsolete. | |
577 | ||
578 | Note that this is just an optimization that isn't necessary for the | |
579 | filesystem to work. */ | |
580 | ||
581 | static int | |
582 | jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset) | |
583 | { | |
584 | /* The `accurate_pos' holds the position of the accurate byte | |
585 | in the jffs_raw_inode structure that we are going to mark | |
586 | as obsolete. */ | |
587 | __u32 accurate_pos = fm_offset + JFFS_RAW_INODE_ACCURATE_OFFSET; | |
588 | unsigned char zero = 0x00; | |
589 | size_t len; | |
590 | ||
591 | D3(printk("jffs_mark_obsolete(): accurate_pos = %u\n", accurate_pos)); | |
592 | ASSERT(if (!fmc) { | |
593 | printk(KERN_ERR "jffs_mark_obsolete(): fmc == NULL\n"); | |
594 | return -1; | |
595 | }); | |
596 | ||
597 | /* Write 0x00 to the raw inode's accurate member. Don't care | |
598 | about the return value. */ | |
599 | MTD_WRITE(fmc->mtd, accurate_pos, 1, &len, &zero); | |
600 | return 0; | |
601 | } | |
602 | ||
603 | #endif /* JFFS_MARK_OBSOLETE */ | |
604 | ||
605 | /* check if it's possible to erase the wanted range, and if not, return | |
606 | * the range that IS erasable, or a negative error code. | |
607 | */ | |
608 | static long | |
609 | jffs_flash_erasable_size(struct mtd_info *mtd, __u32 offset, __u32 size) | |
610 | { | |
611 | u_long ssize; | |
612 | ||
613 | /* assume that sector size for a partition is constant even | |
614 | * if it spans more than one chip (you usually put the same | |
615 | * type of chips in a system) | |
616 | */ | |
617 | ||
618 | ssize = mtd->erasesize; | |
619 | ||
620 | if (offset % ssize) { | |
621 | printk(KERN_WARNING "jffs_flash_erasable_size() given non-aligned offset %x (erasesize %lx)\n", offset, ssize); | |
622 | /* The offset is not sector size aligned. */ | |
623 | return -1; | |
624 | } | |
625 | else if (offset > mtd->size) { | |
626 | printk(KERN_WARNING "jffs_flash_erasable_size given offset off the end of device (%x > %x)\n", offset, mtd->size); | |
627 | return -2; | |
628 | } | |
629 | else if (offset + size > mtd->size) { | |
630 | printk(KERN_WARNING "jffs_flash_erasable_size() given length which runs off the end of device (ofs %x + len %x = %x, > %x)\n", offset,size, offset+size, mtd->size); | |
631 | return -3; | |
632 | } | |
633 | ||
634 | return (size / ssize) * ssize; | |
635 | } | |
636 | ||
637 | ||
638 | /* How much dirty flash memory is possible to erase at the moment? */ | |
639 | long | |
640 | jffs_erasable_size(struct jffs_fmcontrol *fmc) | |
641 | { | |
642 | struct jffs_fm *fm; | |
643 | __u32 size = 0; | |
644 | long ret; | |
645 | ||
646 | ASSERT(if (!fmc) { | |
647 | printk(KERN_ERR "jffs_erasable_size(): fmc = NULL\n"); | |
648 | return -1; | |
649 | }); | |
650 | ||
651 | if (!fmc->head) { | |
652 | /* The flash memory is totally empty. No nodes. No dirt. | |
653 | Just return. */ | |
654 | return 0; | |
655 | } | |
656 | ||
657 | /* Calculate how much space that is dirty. */ | |
658 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next) { | |
659 | if (size && fm->offset == 0) { | |
660 | /* We have reached the beginning of the flash. */ | |
661 | break; | |
662 | } | |
663 | size += fm->size; | |
664 | } | |
665 | ||
666 | /* Someone's signature contained this: | |
667 | There's a fine line between fishing and just standing on | |
668 | the shore like an idiot... */ | |
669 | ret = jffs_flash_erasable_size(fmc->mtd, fmc->head->offset, size); | |
670 | ||
671 | ASSERT(if (ret < 0) { | |
672 | printk("jffs_erasable_size: flash_erasable_size() " | |
673 | "returned something less than zero (%ld).\n", ret); | |
674 | printk("jffs_erasable_size: offset = 0x%08x\n", | |
675 | fmc->head->offset); | |
676 | }); | |
677 | ||
678 | /* If there is dirt on the flash (which is the reason to why | |
679 | this function was called in the first place) but no space is | |
680 | possible to erase right now, the initial part of the list of | |
681 | jffs_fm structs, that hold place for dirty space, could perhaps | |
682 | be shortened. The list's initial "dirty" elements are merged | |
683 | into just one large dirty jffs_fm struct. This operation must | |
684 | only be performed if nothing is possible to erase. Otherwise, | |
685 | jffs_clear_end_of_node() won't work as expected. */ | |
686 | if (ret == 0) { | |
687 | struct jffs_fm *head = fmc->head; | |
688 | struct jffs_fm *del; | |
689 | /* While there are two dirty nodes beside each other.*/ | |
690 | while (head->nodes == 0 | |
691 | && head->next | |
692 | && head->next->nodes == 0) { | |
693 | del = head->next; | |
694 | head->size += del->size; | |
695 | head->next = del->next; | |
696 | if (del->next) { | |
697 | del->next->prev = head; | |
698 | } | |
699 | jffs_free_fm(del); | |
700 | } | |
701 | } | |
702 | ||
703 | return (ret >= 0 ? ret : 0); | |
704 | } | |
705 | ||
706 | static struct jffs_fm *jffs_alloc_fm(void) | |
707 | { | |
708 | struct jffs_fm *fm; | |
709 | ||
710 | fm = kmem_cache_alloc(fm_cache,GFP_KERNEL); | |
711 | DJM(if (fm) no_jffs_fm++;); | |
712 | ||
713 | return fm; | |
714 | } | |
715 | ||
716 | static void jffs_free_fm(struct jffs_fm *n) | |
717 | { | |
718 | kmem_cache_free(fm_cache,n); | |
719 | DJM(no_jffs_fm--); | |
720 | } | |
721 | ||
722 | ||
723 | ||
724 | struct jffs_node *jffs_alloc_node(void) | |
725 | { | |
726 | struct jffs_node *n; | |
727 | ||
728 | n = (struct jffs_node *)kmem_cache_alloc(node_cache,GFP_KERNEL); | |
729 | if(n != NULL) | |
730 | no_jffs_node++; | |
731 | return n; | |
732 | } | |
733 | ||
734 | void jffs_free_node(struct jffs_node *n) | |
735 | { | |
736 | kmem_cache_free(node_cache,n); | |
737 | no_jffs_node--; | |
738 | } | |
739 | ||
740 | ||
741 | int jffs_get_node_inuse(void) | |
742 | { | |
743 | return no_jffs_node; | |
744 | } | |
745 | ||
746 | void | |
747 | jffs_print_fmcontrol(struct jffs_fmcontrol *fmc) | |
748 | { | |
749 | D(printk("struct jffs_fmcontrol: 0x%p\n", fmc)); | |
750 | D(printk("{\n")); | |
751 | D(printk(" %u, /* flash_size */\n", fmc->flash_size)); | |
752 | D(printk(" %u, /* used_size */\n", fmc->used_size)); | |
753 | D(printk(" %u, /* dirty_size */\n", fmc->dirty_size)); | |
754 | D(printk(" %u, /* free_size */\n", fmc->free_size)); | |
755 | D(printk(" %u, /* sector_size */\n", fmc->sector_size)); | |
756 | D(printk(" %u, /* min_free_size */\n", fmc->min_free_size)); | |
757 | D(printk(" %u, /* max_chunk_size */\n", fmc->max_chunk_size)); | |
758 | D(printk(" 0x%p, /* mtd */\n", fmc->mtd)); | |
759 | D(printk(" 0x%p, /* head */ " | |
760 | "(head->offset = 0x%08x)\n", | |
761 | fmc->head, (fmc->head ? fmc->head->offset : 0))); | |
762 | D(printk(" 0x%p, /* tail */ " | |
763 | "(tail->offset + tail->size = 0x%08x)\n", | |
764 | fmc->tail, | |
765 | (fmc->tail ? fmc->tail->offset + fmc->tail->size : 0))); | |
766 | D(printk(" 0x%p, /* head_extra */\n", fmc->head_extra)); | |
767 | D(printk(" 0x%p, /* tail_extra */\n", fmc->tail_extra)); | |
768 | D(printk("}\n")); | |
769 | } | |
770 | ||
771 | void | |
772 | jffs_print_fm(struct jffs_fm *fm) | |
773 | { | |
774 | D(printk("struct jffs_fm: 0x%p\n", fm)); | |
775 | D(printk("{\n")); | |
776 | D(printk(" 0x%08x, /* offset */\n", fm->offset)); | |
777 | D(printk(" %u, /* size */\n", fm->size)); | |
778 | D(printk(" 0x%p, /* prev */\n", fm->prev)); | |
779 | D(printk(" 0x%p, /* next */\n", fm->next)); | |
780 | D(printk(" 0x%p, /* nodes */\n", fm->nodes)); | |
781 | D(printk("}\n")); | |
782 | } | |
783 | ||
784 | #if 0 | |
785 | void | |
786 | jffs_print_node_ref(struct jffs_node_ref *ref) | |
787 | { | |
788 | D(printk("struct jffs_node_ref: 0x%p\n", ref)); | |
789 | D(printk("{\n")); | |
790 | D(printk(" 0x%p, /* node */\n", ref->node)); | |
791 | D(printk(" 0x%p, /* next */\n", ref->next)); | |
792 | D(printk("}\n")); | |
793 | } | |
794 | #endif /* 0 */ | |
795 |