Commit | Line | Data |
---|---|---|
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 | ||
94c9eca2 AB |
34 | #if CONFIG_JFFS_FS_VERBOSE > 0 |
35 | void | |
36 | jffs_print_fmcontrol(struct jffs_fmcontrol *fmc) | |
37 | { | |
38 | D(printk("struct jffs_fmcontrol: 0x%p\n", fmc)); | |
39 | D(printk("{\n")); | |
40 | D(printk(" %u, /* flash_size */\n", fmc->flash_size)); | |
41 | D(printk(" %u, /* used_size */\n", fmc->used_size)); | |
42 | D(printk(" %u, /* dirty_size */\n", fmc->dirty_size)); | |
43 | D(printk(" %u, /* free_size */\n", fmc->free_size)); | |
44 | D(printk(" %u, /* sector_size */\n", fmc->sector_size)); | |
45 | D(printk(" %u, /* min_free_size */\n", fmc->min_free_size)); | |
46 | D(printk(" %u, /* max_chunk_size */\n", fmc->max_chunk_size)); | |
47 | D(printk(" 0x%p, /* mtd */\n", fmc->mtd)); | |
48 | D(printk(" 0x%p, /* head */ " | |
49 | "(head->offset = 0x%08x)\n", | |
50 | fmc->head, (fmc->head ? fmc->head->offset : 0))); | |
51 | D(printk(" 0x%p, /* tail */ " | |
52 | "(tail->offset + tail->size = 0x%08x)\n", | |
53 | fmc->tail, | |
54 | (fmc->tail ? fmc->tail->offset + fmc->tail->size : 0))); | |
55 | D(printk(" 0x%p, /* head_extra */\n", fmc->head_extra)); | |
56 | D(printk(" 0x%p, /* tail_extra */\n", fmc->tail_extra)); | |
57 | D(printk("}\n")); | |
58 | } | |
59 | #endif /* CONFIG_JFFS_FS_VERBOSE > 0 */ | |
60 | ||
61 | #if CONFIG_JFFS_FS_VERBOSE > 2 | |
62 | static void | |
63 | jffs_print_fm(struct jffs_fm *fm) | |
64 | { | |
65 | D(printk("struct jffs_fm: 0x%p\n", fm)); | |
66 | D(printk("{\n")); | |
67 | D(printk(" 0x%08x, /* offset */\n", fm->offset)); | |
68 | D(printk(" %u, /* size */\n", fm->size)); | |
69 | D(printk(" 0x%p, /* prev */\n", fm->prev)); | |
70 | D(printk(" 0x%p, /* next */\n", fm->next)); | |
71 | D(printk(" 0x%p, /* nodes */\n", fm->nodes)); | |
72 | D(printk("}\n")); | |
73 | } | |
74 | #endif /* CONFIG_JFFS_FS_VERBOSE > 2 */ | |
75 | ||
76 | #if 0 | |
77 | void | |
78 | jffs_print_node_ref(struct jffs_node_ref *ref) | |
79 | { | |
80 | D(printk("struct jffs_node_ref: 0x%p\n", ref)); | |
81 | D(printk("{\n")); | |
82 | D(printk(" 0x%p, /* node */\n", ref->node)); | |
83 | D(printk(" 0x%p, /* next */\n", ref->next)); | |
84 | D(printk("}\n")); | |
85 | } | |
86 | #endif /* 0 */ | |
87 | ||
1da177e4 LT |
88 | /* This function creates a new shiny flash memory control structure. */ |
89 | struct jffs_fmcontrol * | |
90 | jffs_build_begin(struct jffs_control *c, int unit) | |
91 | { | |
92 | struct jffs_fmcontrol *fmc; | |
93 | struct mtd_info *mtd; | |
94 | ||
95 | D3(printk("jffs_build_begin()\n")); | |
96 | fmc = (struct jffs_fmcontrol *)kmalloc(sizeof(struct jffs_fmcontrol), | |
97 | GFP_KERNEL); | |
98 | if (!fmc) { | |
99 | D(printk("jffs_build_begin(): Allocation of " | |
100 | "struct jffs_fmcontrol failed!\n")); | |
101 | return (struct jffs_fmcontrol *)0; | |
102 | } | |
103 | DJM(no_jffs_fmcontrol++); | |
104 | ||
105 | mtd = get_mtd_device(NULL, unit); | |
106 | ||
107 | if (!mtd) { | |
108 | kfree(fmc); | |
109 | DJM(no_jffs_fmcontrol--); | |
110 | return NULL; | |
111 | } | |
112 | ||
113 | /* Retrieve the size of the flash memory. */ | |
114 | fmc->flash_size = mtd->size; | |
115 | D3(printk(" fmc->flash_size = %d bytes\n", fmc->flash_size)); | |
116 | ||
117 | fmc->used_size = 0; | |
118 | fmc->dirty_size = 0; | |
119 | fmc->free_size = mtd->size; | |
120 | fmc->sector_size = mtd->erasesize; | |
121 | fmc->max_chunk_size = fmc->sector_size >> 1; | |
122 | /* min_free_size: | |
123 | 1 sector, obviously. | |
124 | + 1 x max_chunk_size, for when a nodes overlaps the end of a sector | |
125 | + 1 x max_chunk_size again, which ought to be enough to handle | |
126 | the case where a rename causes a name to grow, and GC has | |
127 | to write out larger nodes than the ones it's obsoleting. | |
128 | We should fix it so it doesn't have to write the name | |
129 | _every_ time. Later. | |
130 | + another 2 sectors because people keep getting GC stuck and | |
131 | we don't know why. This scares me - I want formal proof | |
132 | of correctness of whatever number we put here. dwmw2. | |
133 | */ | |
134 | fmc->min_free_size = fmc->sector_size << 2; | |
135 | fmc->mtd = mtd; | |
136 | fmc->c = c; | |
137 | fmc->head = NULL; | |
138 | fmc->tail = NULL; | |
139 | fmc->head_extra = NULL; | |
140 | fmc->tail_extra = NULL; | |
141 | init_MUTEX(&fmc->biglock); | |
142 | return fmc; | |
143 | } | |
144 | ||
145 | ||
146 | /* When the flash memory scan has completed, this function should be called | |
147 | before use of the control structure. */ | |
148 | void | |
149 | jffs_build_end(struct jffs_fmcontrol *fmc) | |
150 | { | |
151 | D3(printk("jffs_build_end()\n")); | |
152 | ||
153 | if (!fmc->head) { | |
154 | fmc->head = fmc->head_extra; | |
155 | fmc->tail = fmc->tail_extra; | |
156 | } | |
157 | else if (fmc->head_extra) { | |
158 | fmc->tail_extra->next = fmc->head; | |
159 | fmc->head->prev = fmc->tail_extra; | |
160 | fmc->head = fmc->head_extra; | |
161 | } | |
162 | fmc->head_extra = NULL; /* These two instructions should be omitted. */ | |
163 | fmc->tail_extra = NULL; | |
164 | D3(jffs_print_fmcontrol(fmc)); | |
165 | } | |
166 | ||
167 | ||
168 | /* Call this function when the file system is unmounted. This function | |
169 | frees all memory used by this module. */ | |
170 | void | |
171 | jffs_cleanup_fmcontrol(struct jffs_fmcontrol *fmc) | |
172 | { | |
173 | if (fmc) { | |
174 | struct jffs_fm *next = fmc->head; | |
175 | while (next) { | |
176 | struct jffs_fm *cur = next; | |
177 | next = next->next; | |
178 | jffs_free_fm(cur); | |
179 | } | |
180 | put_mtd_device(fmc->mtd); | |
181 | kfree(fmc); | |
182 | DJM(no_jffs_fmcontrol--); | |
183 | } | |
184 | } | |
185 | ||
186 | ||
187 | /* This function returns the size of the first chunk of free space on the | |
188 | flash memory. This function will return something nonzero if the flash | |
189 | memory contains any free space. */ | |
190 | __u32 | |
191 | jffs_free_size1(struct jffs_fmcontrol *fmc) | |
192 | { | |
193 | __u32 head; | |
194 | __u32 tail; | |
195 | __u32 end = fmc->flash_size; | |
196 | ||
197 | if (!fmc->head) { | |
198 | /* There is nothing on the flash. */ | |
199 | return fmc->flash_size; | |
200 | } | |
201 | ||
202 | /* Compute the beginning and ending of the contents of the flash. */ | |
203 | head = fmc->head->offset; | |
204 | tail = fmc->tail->offset + fmc->tail->size; | |
205 | if (tail == end) { | |
206 | tail = 0; | |
207 | } | |
208 | ASSERT(else if (tail > end) { | |
209 | printk(KERN_WARNING "jffs_free_size1(): tail > end\n"); | |
210 | tail = 0; | |
211 | }); | |
212 | ||
213 | if (head <= tail) { | |
214 | return end - tail; | |
215 | } | |
216 | else { | |
217 | return head - tail; | |
218 | } | |
219 | } | |
220 | ||
221 | /* This function will return something nonzero in case there are two free | |
222 | areas on the flash. Like this: | |
223 | ||
224 | +----------------+------------------+----------------+ | |
225 | | FREE 1 | USED / DIRTY | FREE 2 | | |
226 | +----------------+------------------+----------------+ | |
227 | fmc->head -----^ | |
228 | fmc->tail ------------------------^ | |
229 | ||
230 | The value returned, will be the size of the first empty area on the | |
231 | flash, in this case marked "FREE 1". */ | |
232 | __u32 | |
233 | jffs_free_size2(struct jffs_fmcontrol *fmc) | |
234 | { | |
235 | if (fmc->head) { | |
236 | __u32 head = fmc->head->offset; | |
237 | __u32 tail = fmc->tail->offset + fmc->tail->size; | |
238 | if (tail == fmc->flash_size) { | |
239 | tail = 0; | |
240 | } | |
241 | ||
242 | if (tail >= head) { | |
243 | return head; | |
244 | } | |
245 | } | |
246 | return 0; | |
247 | } | |
248 | ||
249 | ||
250 | /* Allocate a chunk of flash memory. If there is enough space on the | |
251 | device, a reference to the associated node is stored in the jffs_fm | |
252 | struct. */ | |
253 | int | |
254 | jffs_fmalloc(struct jffs_fmcontrol *fmc, __u32 size, struct jffs_node *node, | |
255 | struct jffs_fm **result) | |
256 | { | |
257 | struct jffs_fm *fm; | |
258 | __u32 free_chunk_size1; | |
259 | __u32 free_chunk_size2; | |
260 | ||
261 | D2(printk("jffs_fmalloc(): fmc = 0x%p, size = %d, " | |
262 | "node = 0x%p\n", fmc, size, node)); | |
263 | ||
264 | *result = NULL; | |
265 | ||
266 | if (!(fm = jffs_alloc_fm())) { | |
267 | D(printk("jffs_fmalloc(): kmalloc() failed! (fm)\n")); | |
268 | return -ENOMEM; | |
269 | } | |
270 | ||
271 | free_chunk_size1 = jffs_free_size1(fmc); | |
272 | free_chunk_size2 = jffs_free_size2(fmc); | |
273 | if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) { | |
274 | printk(KERN_WARNING "Free size accounting screwed\n"); | |
275 | 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); | |
276 | } | |
277 | ||
278 | D3(printk("jffs_fmalloc(): free_chunk_size1 = %u, " | |
279 | "free_chunk_size2 = %u\n", | |
280 | free_chunk_size1, free_chunk_size2)); | |
281 | ||
282 | if (size <= free_chunk_size1) { | |
283 | if (!(fm->nodes = (struct jffs_node_ref *) | |
284 | kmalloc(sizeof(struct jffs_node_ref), | |
285 | GFP_KERNEL))) { | |
286 | D(printk("jffs_fmalloc(): kmalloc() failed! " | |
287 | "(node_ref)\n")); | |
288 | jffs_free_fm(fm); | |
289 | return -ENOMEM; | |
290 | } | |
291 | DJM(no_jffs_node_ref++); | |
292 | fm->nodes->node = node; | |
293 | fm->nodes->next = NULL; | |
294 | if (fmc->tail) { | |
295 | fm->offset = fmc->tail->offset + fmc->tail->size; | |
296 | if (fm->offset == fmc->flash_size) { | |
297 | fm->offset = 0; | |
298 | } | |
299 | ASSERT(else if (fm->offset > fmc->flash_size) { | |
300 | printk(KERN_WARNING "jffs_fmalloc(): " | |
301 | "offset > flash_end\n"); | |
302 | fm->offset = 0; | |
303 | }); | |
304 | } | |
305 | else { | |
306 | /* There don't have to be files in the file | |
307 | system yet. */ | |
308 | fm->offset = 0; | |
309 | } | |
310 | fm->size = size; | |
311 | fmc->free_size -= size; | |
312 | fmc->used_size += size; | |
313 | } | |
314 | else if (size > free_chunk_size2) { | |
315 | printk(KERN_WARNING "JFFS: Tried to allocate a too " | |
316 | "large flash memory chunk. (size = %u)\n", size); | |
317 | jffs_free_fm(fm); | |
318 | return -ENOSPC; | |
319 | } | |
320 | else { | |
321 | fm->offset = fmc->tail->offset + fmc->tail->size; | |
322 | fm->size = free_chunk_size1; | |
323 | fm->nodes = NULL; | |
324 | fmc->free_size -= fm->size; | |
325 | fmc->dirty_size += fm->size; /* Changed by simonk. This seemingly fixes a | |
326 | bug that caused infinite garbage collection. | |
327 | It previously set fmc->dirty_size to size (which is the | |
328 | size of the requested chunk). | |
329 | */ | |
330 | } | |
331 | ||
332 | fm->next = NULL; | |
333 | if (!fmc->head) { | |
334 | fm->prev = NULL; | |
335 | fmc->head = fm; | |
336 | fmc->tail = fm; | |
337 | } | |
338 | else { | |
339 | fm->prev = fmc->tail; | |
340 | fmc->tail->next = fm; | |
341 | fmc->tail = fm; | |
342 | } | |
343 | ||
344 | D3(jffs_print_fmcontrol(fmc)); | |
345 | D3(jffs_print_fm(fm)); | |
346 | *result = fm; | |
347 | return 0; | |
348 | } | |
349 | ||
350 | ||
351 | /* The on-flash space is not needed anymore by the passed node. Remove | |
352 | the reference to the node from the node list. If the data chunk in | |
353 | the flash memory isn't used by any more nodes anymore (fm->nodes == 0), | |
354 | then mark that chunk as dirty. */ | |
355 | int | |
356 | jffs_fmfree(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, struct jffs_node *node) | |
357 | { | |
358 | struct jffs_node_ref *ref; | |
359 | struct jffs_node_ref *prev; | |
360 | ASSERT(int del = 0); | |
361 | ||
362 | D2(printk("jffs_fmfree(): node->ino = %u, node->version = %u\n", | |
363 | node->ino, node->version)); | |
364 | ||
365 | ASSERT(if (!fmc || !fm || !fm->nodes) { | |
366 | printk(KERN_ERR "jffs_fmfree(): fmc: 0x%p, fm: 0x%p, " | |
367 | "fm->nodes: 0x%p\n", | |
368 | fmc, fm, (fm ? fm->nodes : NULL)); | |
369 | return -1; | |
370 | }); | |
371 | ||
372 | /* Find the reference to the node that is going to be removed | |
373 | and remove it. */ | |
374 | for (ref = fm->nodes, prev = NULL; ref; ref = ref->next) { | |
375 | if (ref->node == node) { | |
376 | if (prev) { | |
377 | prev->next = ref->next; | |
378 | } | |
379 | else { | |
380 | fm->nodes = ref->next; | |
381 | } | |
382 | kfree(ref); | |
383 | DJM(no_jffs_node_ref--); | |
384 | ASSERT(del = 1); | |
385 | break; | |
386 | } | |
387 | prev = ref; | |
388 | } | |
389 | ||
390 | /* If the data chunk in the flash memory isn't used anymore | |
391 | just mark it as obsolete. */ | |
392 | if (!fm->nodes) { | |
393 | /* No node uses this chunk so let's remove it. */ | |
394 | fmc->used_size -= fm->size; | |
395 | fmc->dirty_size += fm->size; | |
396 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE | |
397 | if (jffs_mark_obsolete(fmc, fm->offset) < 0) { | |
398 | D1(printk("jffs_fmfree(): Failed to mark an on-flash " | |
399 | "node obsolete!\n")); | |
400 | return -1; | |
401 | } | |
402 | #endif | |
403 | } | |
404 | ||
405 | ASSERT(if (!del) { | |
406 | printk(KERN_WARNING "***jffs_fmfree(): " | |
407 | "Didn't delete any node reference!\n"); | |
408 | }); | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | ||
414 | /* This allocation function is used during the initialization of | |
415 | the file system. */ | |
416 | struct jffs_fm * | |
417 | jffs_fmalloced(struct jffs_fmcontrol *fmc, __u32 offset, __u32 size, | |
418 | struct jffs_node *node) | |
419 | { | |
420 | struct jffs_fm *fm; | |
421 | ||
422 | D3(printk("jffs_fmalloced()\n")); | |
423 | ||
424 | if (!(fm = jffs_alloc_fm())) { | |
425 | D(printk("jffs_fmalloced(0x%p, %u, %u, 0x%p): failed!\n", | |
426 | fmc, offset, size, node)); | |
427 | return NULL; | |
428 | } | |
429 | fm->offset = offset; | |
430 | fm->size = size; | |
431 | fm->prev = NULL; | |
432 | fm->next = NULL; | |
433 | fm->nodes = NULL; | |
434 | if (node) { | |
435 | /* `node' exists and it should be associated with the | |
436 | jffs_fm structure `fm'. */ | |
437 | if (!(fm->nodes = (struct jffs_node_ref *) | |
438 | kmalloc(sizeof(struct jffs_node_ref), | |
439 | GFP_KERNEL))) { | |
440 | D(printk("jffs_fmalloced(): !fm->nodes\n")); | |
441 | jffs_free_fm(fm); | |
442 | return NULL; | |
443 | } | |
444 | DJM(no_jffs_node_ref++); | |
445 | fm->nodes->node = node; | |
446 | fm->nodes->next = NULL; | |
447 | fmc->used_size += size; | |
448 | fmc->free_size -= size; | |
449 | } | |
450 | else { | |
451 | /* If there is no node, then this is just a chunk of dirt. */ | |
452 | fmc->dirty_size += size; | |
453 | fmc->free_size -= size; | |
454 | } | |
455 | ||
456 | if (fmc->head_extra) { | |
457 | fm->prev = fmc->tail_extra; | |
458 | fmc->tail_extra->next = fm; | |
459 | fmc->tail_extra = fm; | |
460 | } | |
461 | else if (!fmc->head) { | |
462 | fmc->head = fm; | |
463 | fmc->tail = fm; | |
464 | } | |
465 | else if (fmc->tail->offset + fmc->tail->size < offset) { | |
466 | fmc->head_extra = fm; | |
467 | fmc->tail_extra = fm; | |
468 | } | |
469 | else { | |
470 | fm->prev = fmc->tail; | |
471 | fmc->tail->next = fm; | |
472 | fmc->tail = fm; | |
473 | } | |
474 | D3(jffs_print_fmcontrol(fmc)); | |
475 | D3(jffs_print_fm(fm)); | |
476 | return fm; | |
477 | } | |
478 | ||
479 | ||
480 | /* Add a new node to an already existing jffs_fm struct. */ | |
481 | int | |
482 | jffs_add_node(struct jffs_node *node) | |
483 | { | |
484 | struct jffs_node_ref *ref; | |
485 | ||
486 | D3(printk("jffs_add_node(): ino = %u\n", node->ino)); | |
487 | ||
488 | ref = (struct jffs_node_ref *)kmalloc(sizeof(struct jffs_node_ref), | |
489 | GFP_KERNEL); | |
490 | if (!ref) | |
491 | return -ENOMEM; | |
492 | ||
493 | DJM(no_jffs_node_ref++); | |
494 | ref->node = node; | |
495 | ref->next = node->fm->nodes; | |
496 | node->fm->nodes = ref; | |
497 | return 0; | |
498 | } | |
499 | ||
500 | ||
501 | /* Free a part of some allocated space. */ | |
502 | void | |
503 | jffs_fmfree_partly(struct jffs_fmcontrol *fmc, struct jffs_fm *fm, __u32 size) | |
504 | { | |
505 | D1(printk("***jffs_fmfree_partly(): fm = 0x%p, fm->nodes = 0x%p, " | |
506 | "fm->nodes->node->ino = %u, size = %u\n", | |
507 | fm, (fm ? fm->nodes : 0), | |
508 | (!fm ? 0 : (!fm->nodes ? 0 : fm->nodes->node->ino)), size)); | |
509 | ||
510 | if (fm->nodes) { | |
511 | kfree(fm->nodes); | |
512 | DJM(no_jffs_node_ref--); | |
513 | fm->nodes = NULL; | |
514 | } | |
515 | fmc->used_size -= fm->size; | |
516 | if (fm == fmc->tail) { | |
517 | fm->size -= size; | |
518 | fmc->free_size += size; | |
519 | } | |
520 | fmc->dirty_size += fm->size; | |
521 | } | |
522 | ||
523 | ||
524 | /* Find the jffs_fm struct that contains the end of the data chunk that | |
525 | begins at the logical beginning of the flash memory and spans `size' | |
526 | bytes. If we want to erase a sector of the flash memory, we use this | |
527 | function to find where the sector limit cuts a chunk of data. */ | |
528 | struct jffs_fm * | |
529 | jffs_cut_node(struct jffs_fmcontrol *fmc, __u32 size) | |
530 | { | |
531 | struct jffs_fm *fm; | |
532 | __u32 pos = 0; | |
533 | ||
534 | if (size == 0) { | |
535 | return NULL; | |
536 | } | |
537 | ||
538 | ASSERT(if (!fmc) { | |
539 | printk(KERN_ERR "jffs_cut_node(): fmc == NULL\n"); | |
540 | return NULL; | |
541 | }); | |
542 | ||
543 | fm = fmc->head; | |
544 | ||
545 | while (fm) { | |
546 | pos += fm->size; | |
547 | if (pos < size) { | |
548 | fm = fm->next; | |
549 | } | |
550 | else if (pos > size) { | |
551 | break; | |
552 | } | |
553 | else { | |
554 | fm = NULL; | |
555 | break; | |
556 | } | |
557 | } | |
558 | ||
559 | return fm; | |
560 | } | |
561 | ||
562 | ||
563 | /* Move the head of the fmc structures and delete the obsolete parts. */ | |
564 | void | |
565 | jffs_sync_erase(struct jffs_fmcontrol *fmc, int erased_size) | |
566 | { | |
567 | struct jffs_fm *fm; | |
568 | struct jffs_fm *del; | |
569 | ||
570 | ASSERT(if (!fmc) { | |
571 | printk(KERN_ERR "jffs_sync_erase(): fmc == NULL\n"); | |
572 | return; | |
573 | }); | |
574 | ||
575 | fmc->dirty_size -= erased_size; | |
576 | fmc->free_size += erased_size; | |
577 | ||
578 | for (fm = fmc->head; fm && (erased_size > 0);) { | |
579 | if (erased_size >= fm->size) { | |
580 | erased_size -= fm->size; | |
581 | del = fm; | |
582 | fm = fm->next; | |
583 | fm->prev = NULL; | |
584 | fmc->head = fm; | |
585 | jffs_free_fm(del); | |
586 | } | |
587 | else { | |
588 | fm->size -= erased_size; | |
589 | fm->offset += erased_size; | |
590 | break; | |
591 | } | |
592 | } | |
593 | } | |
594 | ||
595 | ||
596 | /* Return the oldest used node in the flash memory. */ | |
597 | struct jffs_node * | |
598 | jffs_get_oldest_node(struct jffs_fmcontrol *fmc) | |
599 | { | |
600 | struct jffs_fm *fm; | |
601 | struct jffs_node_ref *nref; | |
602 | struct jffs_node *node = NULL; | |
603 | ||
604 | ASSERT(if (!fmc) { | |
605 | printk(KERN_ERR "jffs_get_oldest_node(): fmc == NULL\n"); | |
606 | return NULL; | |
607 | }); | |
608 | ||
609 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next); | |
610 | ||
611 | if (!fm) { | |
612 | return NULL; | |
613 | } | |
614 | ||
615 | /* The oldest node is the last one in the reference list. This list | |
616 | shouldn't be too long; just one or perhaps two elements. */ | |
617 | for (nref = fm->nodes; nref; nref = nref->next) { | |
618 | node = nref->node; | |
619 | } | |
620 | ||
621 | D2(printk("jffs_get_oldest_node(): ino = %u, version = %u\n", | |
622 | (node ? node->ino : 0), (node ? node->version : 0))); | |
623 | ||
624 | return node; | |
625 | } | |
626 | ||
627 | ||
628 | #if defined(JFFS_MARK_OBSOLETE) && JFFS_MARK_OBSOLETE | |
629 | ||
630 | /* Mark an on-flash node as obsolete. | |
631 | ||
632 | Note that this is just an optimization that isn't necessary for the | |
633 | filesystem to work. */ | |
634 | ||
635 | static int | |
636 | jffs_mark_obsolete(struct jffs_fmcontrol *fmc, __u32 fm_offset) | |
637 | { | |
638 | /* The `accurate_pos' holds the position of the accurate byte | |
639 | in the jffs_raw_inode structure that we are going to mark | |
640 | as obsolete. */ | |
641 | __u32 accurate_pos = fm_offset + JFFS_RAW_INODE_ACCURATE_OFFSET; | |
642 | unsigned char zero = 0x00; | |
643 | size_t len; | |
644 | ||
645 | D3(printk("jffs_mark_obsolete(): accurate_pos = %u\n", accurate_pos)); | |
646 | ASSERT(if (!fmc) { | |
647 | printk(KERN_ERR "jffs_mark_obsolete(): fmc == NULL\n"); | |
648 | return -1; | |
649 | }); | |
650 | ||
651 | /* Write 0x00 to the raw inode's accurate member. Don't care | |
652 | about the return value. */ | |
653 | MTD_WRITE(fmc->mtd, accurate_pos, 1, &len, &zero); | |
654 | return 0; | |
655 | } | |
656 | ||
657 | #endif /* JFFS_MARK_OBSOLETE */ | |
658 | ||
659 | /* check if it's possible to erase the wanted range, and if not, return | |
660 | * the range that IS erasable, or a negative error code. | |
661 | */ | |
662 | static long | |
663 | jffs_flash_erasable_size(struct mtd_info *mtd, __u32 offset, __u32 size) | |
664 | { | |
665 | u_long ssize; | |
666 | ||
667 | /* assume that sector size for a partition is constant even | |
668 | * if it spans more than one chip (you usually put the same | |
669 | * type of chips in a system) | |
670 | */ | |
671 | ||
672 | ssize = mtd->erasesize; | |
673 | ||
674 | if (offset % ssize) { | |
675 | printk(KERN_WARNING "jffs_flash_erasable_size() given non-aligned offset %x (erasesize %lx)\n", offset, ssize); | |
676 | /* The offset is not sector size aligned. */ | |
677 | return -1; | |
678 | } | |
679 | else if (offset > mtd->size) { | |
680 | printk(KERN_WARNING "jffs_flash_erasable_size given offset off the end of device (%x > %x)\n", offset, mtd->size); | |
681 | return -2; | |
682 | } | |
683 | else if (offset + size > mtd->size) { | |
684 | 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); | |
685 | return -3; | |
686 | } | |
687 | ||
688 | return (size / ssize) * ssize; | |
689 | } | |
690 | ||
691 | ||
692 | /* How much dirty flash memory is possible to erase at the moment? */ | |
693 | long | |
694 | jffs_erasable_size(struct jffs_fmcontrol *fmc) | |
695 | { | |
696 | struct jffs_fm *fm; | |
697 | __u32 size = 0; | |
698 | long ret; | |
699 | ||
700 | ASSERT(if (!fmc) { | |
701 | printk(KERN_ERR "jffs_erasable_size(): fmc = NULL\n"); | |
702 | return -1; | |
703 | }); | |
704 | ||
705 | if (!fmc->head) { | |
706 | /* The flash memory is totally empty. No nodes. No dirt. | |
707 | Just return. */ | |
708 | return 0; | |
709 | } | |
710 | ||
711 | /* Calculate how much space that is dirty. */ | |
712 | for (fm = fmc->head; fm && !fm->nodes; fm = fm->next) { | |
713 | if (size && fm->offset == 0) { | |
714 | /* We have reached the beginning of the flash. */ | |
715 | break; | |
716 | } | |
717 | size += fm->size; | |
718 | } | |
719 | ||
720 | /* Someone's signature contained this: | |
721 | There's a fine line between fishing and just standing on | |
722 | the shore like an idiot... */ | |
723 | ret = jffs_flash_erasable_size(fmc->mtd, fmc->head->offset, size); | |
724 | ||
725 | ASSERT(if (ret < 0) { | |
726 | printk("jffs_erasable_size: flash_erasable_size() " | |
727 | "returned something less than zero (%ld).\n", ret); | |
728 | printk("jffs_erasable_size: offset = 0x%08x\n", | |
729 | fmc->head->offset); | |
730 | }); | |
731 | ||
732 | /* If there is dirt on the flash (which is the reason to why | |
733 | this function was called in the first place) but no space is | |
734 | possible to erase right now, the initial part of the list of | |
735 | jffs_fm structs, that hold place for dirty space, could perhaps | |
736 | be shortened. The list's initial "dirty" elements are merged | |
737 | into just one large dirty jffs_fm struct. This operation must | |
738 | only be performed if nothing is possible to erase. Otherwise, | |
739 | jffs_clear_end_of_node() won't work as expected. */ | |
740 | if (ret == 0) { | |
741 | struct jffs_fm *head = fmc->head; | |
742 | struct jffs_fm *del; | |
743 | /* While there are two dirty nodes beside each other.*/ | |
744 | while (head->nodes == 0 | |
745 | && head->next | |
746 | && head->next->nodes == 0) { | |
747 | del = head->next; | |
748 | head->size += del->size; | |
749 | head->next = del->next; | |
750 | if (del->next) { | |
751 | del->next->prev = head; | |
752 | } | |
753 | jffs_free_fm(del); | |
754 | } | |
755 | } | |
756 | ||
757 | return (ret >= 0 ? ret : 0); | |
758 | } | |
759 | ||
760 | static struct jffs_fm *jffs_alloc_fm(void) | |
761 | { | |
762 | struct jffs_fm *fm; | |
763 | ||
764 | fm = kmem_cache_alloc(fm_cache,GFP_KERNEL); | |
765 | DJM(if (fm) no_jffs_fm++;); | |
766 | ||
767 | return fm; | |
768 | } | |
769 | ||
770 | static void jffs_free_fm(struct jffs_fm *n) | |
771 | { | |
772 | kmem_cache_free(fm_cache,n); | |
773 | DJM(no_jffs_fm--); | |
774 | } | |
775 | ||
776 | ||
777 | ||
778 | struct jffs_node *jffs_alloc_node(void) | |
779 | { | |
780 | struct jffs_node *n; | |
781 | ||
782 | n = (struct jffs_node *)kmem_cache_alloc(node_cache,GFP_KERNEL); | |
783 | if(n != NULL) | |
784 | no_jffs_node++; | |
785 | return n; | |
786 | } | |
787 | ||
788 | void jffs_free_node(struct jffs_node *n) | |
789 | { | |
790 | kmem_cache_free(node_cache,n); | |
791 | no_jffs_node--; | |
792 | } | |
793 | ||
794 | ||
795 | int jffs_get_node_inuse(void) | |
796 | { | |
797 | return no_jffs_node; | |
798 | } |