diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/jffs/jffs_fm.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/jffs/jffs_fm.c')
-rw-r--r-- | fs/jffs/jffs_fm.c | 795 |
1 files changed, 795 insertions, 0 deletions
diff --git a/fs/jffs/jffs_fm.c b/fs/jffs/jffs_fm.c new file mode 100644 index 000000000000..0cab8da49d3c --- /dev/null +++ b/fs/jffs/jffs_fm.c | |||
@@ -0,0 +1,795 @@ | |||
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 | |||