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[deliverable/linux.git] / fs / jffs / intrep.c
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1da177e4
LT		 1/*
2 * JFFS -- Journaling Flash File System, Linux implementation.
3 *
4 * Copyright (C) 1999, 2000 Axis Communications, Inc.
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: intrep.c,v 1.102 2001/09/23 23:28:36 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
20/* This file contains the code for the internal structure of the
21 Journaling Flash File System, JFFS. */
22
23/*
24 * Todo list:
25 *
26 * memcpy_to_flash() and memcpy_from_flash() functions.
27 *
28 * Implementation of hard links.
29 *
30 * Organize the source code in a better way. Against the VFS we could
31 * have jffs_ext.c, and against the block device jffs_int.c.
32 * A better file-internal organization too.
33 *
34 * A better checksum algorithm.
35 *
36 * Consider endianness stuff. ntohl() etc.
37 *
38 * Are we handling the atime, mtime, ctime members of the inode right?
39 *
40 * Remove some duplicated code. Take a look at jffs_write_node() and
41 * jffs_rewrite_data() for instance.
42 *
43 * Implement more meaning of the nlink member in various data structures.
44 * nlink could be used in conjunction with hard links for instance.
45 *
46 * Better memory management. Allocate data structures in larger chunks
47 * if possible.
48 *
49 * If too much meta data is stored, a garbage collect should be issued.
50 * We have experienced problems with too much meta data with for instance
51 * log files.
52 *
53 * Improve the calls to jffs_ioctl(). We would like to retrieve more
54 * information to be able to debug (or to supervise) JFFS during run-time.
55 *
56 */
57
58#include <linux/config.h>
59#include <linux/types.h>
60#include <linux/slab.h>
61#include <linux/jffs.h>
62#include <linux/fs.h>
63#include <linux/stat.h>
64#include <linux/pagemap.h>
65#include <asm/semaphore.h>
66#include <asm/byteorder.h>
67#include <linux/smp_lock.h>
68#include <linux/time.h>
69#include <linux/ctype.h>
70
71#include "intrep.h"
72#include "jffs_fm.h"
73
74long no_jffs_node = 0;
75static long no_jffs_file = 0;
76#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
77long no_jffs_control = 0;
78long no_jffs_raw_inode = 0;
79long no_jffs_node_ref = 0;
80long no_jffs_fm = 0;
81long no_jffs_fmcontrol = 0;
82long no_hash = 0;
83long no_name = 0;
84#endif
85
86static int jffs_scan_flash(struct jffs_control *c);
87static int jffs_update_file(struct jffs_file *f, struct jffs_node *node);
88static int jffs_build_file(struct jffs_file *f);
89static int jffs_free_file(struct jffs_file *f);
90static int jffs_free_node_list(struct jffs_file *f);
91static int jffs_garbage_collect_now(struct jffs_control *c);
92static int jffs_insert_file_into_hash(struct jffs_file *f);
93static int jffs_remove_redundant_nodes(struct jffs_file *f);
94
95/* Is there enough space on the flash? */
96static inline int JFFS_ENOUGH_SPACE(struct jffs_control *c, __u32 space)
97{
98 struct jffs_fmcontrol *fmc = c->fmc;
99
100 while (1) {
101 if ((fmc->flash_size - (fmc->used_size + fmc->dirty_size))
102 >= fmc->min_free_size + space) {
103 return 1;
104 }
105 if (fmc->dirty_size < fmc->sector_size)
106 return 0;
107
108 if (jffs_garbage_collect_now(c)) {
109 D1(printk("JFFS_ENOUGH_SPACE: jffs_garbage_collect_now() failed.\n"));
110 return 0;
111 }
112 }
113}
114
115#if CONFIG_JFFS_FS_VERBOSE > 0
116static __u8
117flash_read_u8(struct mtd_info *mtd, loff_t from)
118{
119 size_t retlen;
120 __u8 ret;
121 int res;
122
123 res = MTD_READ(mtd, from, 1, &retlen, &ret);
124 if (retlen != 1) {
125 printk("Didn't read a byte in flash_read_u8(). Returned %d\n", res);
126 return 0;
127 }
128
129 return ret;
130}
131
132static void
133jffs_hexdump(struct mtd_info *mtd, loff_t pos, int size)
134{
135 char line[16];
136 int j = 0;
137
138 while (size > 0) {
139 int i;
140
141 printk("%ld:", (long) pos);
142 for (j = 0; j < 16; j++) {
143 line[j] = flash_read_u8(mtd, pos++);
144 }
145 for (i = 0; i < j; i++) {
146 if (!(i & 1)) {
147 printk(" %.2x", line[i] & 0xff);
148 }
149 else {
150 printk("%.2x", line[i] & 0xff);
151 }
152 }
153
154 /* Print empty space */
155 for (; i < 16; i++) {
156 if (!(i & 1)) {
157 printk(" ");
158 }
159 else {
160 printk(" ");
161 }
162 }
163 printk(" ");
164
165 for (i = 0; i < j; i++) {
166 if (isgraph(line[i])) {
167 printk("%c", line[i]);
168 }
169 else {
170 printk(".");
171 }
172 }
173 printk("\n");
174 size -= 16;
175 }
176}
177
94c9eca2
AB		 178/* Print the contents of a node. */
179static void
180jffs_print_node(struct jffs_node *n)
181{
182 D(printk("jffs_node: 0x%p\n", n));
183 D(printk("{\n"));
184 D(printk(" 0x%08x, /* version */\n", n->version));
185 D(printk(" 0x%08x, /* data_offset */\n", n->data_offset));
186 D(printk(" 0x%08x, /* data_size */\n", n->data_size));
187 D(printk(" 0x%08x, /* removed_size */\n", n->removed_size));
188 D(printk(" 0x%08x, /* fm_offset */\n", n->fm_offset));
189 D(printk(" 0x%02x, /* name_size */\n", n->name_size));
190 D(printk(" 0x%p, /* fm, fm->offset: %u */\n",
191 n->fm, (n->fm ? n->fm->offset : 0)));
192 D(printk(" 0x%p, /* version_prev */\n", n->version_prev));
193 D(printk(" 0x%p, /* version_next */\n", n->version_next));
194 D(printk(" 0x%p, /* range_prev */\n", n->range_prev));
195 D(printk(" 0x%p, /* range_next */\n", n->range_next));
196 D(printk("}\n"));
197}
198
1da177e4
LT		 199#endif
200
94c9eca2
AB		 201/* Print the contents of a raw inode. */
202static void
203jffs_print_raw_inode(struct jffs_raw_inode *raw_inode)
204{
205 D(printk("jffs_raw_inode: inode number: %u\n", raw_inode->ino));
206 D(printk("{\n"));
207 D(printk(" 0x%08x, /* magic */\n", raw_inode->magic));
208 D(printk(" 0x%08x, /* ino */\n", raw_inode->ino));
209 D(printk(" 0x%08x, /* pino */\n", raw_inode->pino));
210 D(printk(" 0x%08x, /* version */\n", raw_inode->version));
211 D(printk(" 0x%08x, /* mode */\n", raw_inode->mode));
212 D(printk(" 0x%04x, /* uid */\n", raw_inode->uid));
213 D(printk(" 0x%04x, /* gid */\n", raw_inode->gid));
214 D(printk(" 0x%08x, /* atime */\n", raw_inode->atime));
215 D(printk(" 0x%08x, /* mtime */\n", raw_inode->mtime));
216 D(printk(" 0x%08x, /* ctime */\n", raw_inode->ctime));
217 D(printk(" 0x%08x, /* offset */\n", raw_inode->offset));
218 D(printk(" 0x%08x, /* dsize */\n", raw_inode->dsize));
219 D(printk(" 0x%08x, /* rsize */\n", raw_inode->rsize));
220 D(printk(" 0x%02x, /* nsize */\n", raw_inode->nsize));
221 D(printk(" 0x%02x, /* nlink */\n", raw_inode->nlink));
222 D(printk(" 0x%02x, /* spare */\n",
223 raw_inode->spare));
224 D(printk(" %u, /* rename */\n",
225 raw_inode->rename));
226 D(printk(" %u, /* deleted */\n",
227 raw_inode->deleted));
228 D(printk(" 0x%02x, /* accurate */\n",
229 raw_inode->accurate));
230 D(printk(" 0x%08x, /* dchksum */\n", raw_inode->dchksum));
231 D(printk(" 0x%04x, /* nchksum */\n", raw_inode->nchksum));
232 D(printk(" 0x%04x, /* chksum */\n", raw_inode->chksum));
233 D(printk("}\n"));
234}
235
1da177e4
LT		 236#define flash_safe_acquire(arg)
237#define flash_safe_release(arg)
238
239
240static int
241flash_safe_read(struct mtd_info *mtd, loff_t from,
242 u_char *buf, size_t count)
243{
244 size_t retlen;
245 int res;
246
247 D3(printk(KERN_NOTICE "flash_safe_read(%p, %08x, %p, %08x)\n",
248 mtd, (unsigned int) from, buf, count));
249
250 res = MTD_READ(mtd, from, count, &retlen, buf);
251 if (retlen != count) {
252 panic("Didn't read all bytes in flash_safe_read(). Returned %d\n", res);
253 }
254 return res?res:retlen;
255}
256
257
258static __u32
259flash_read_u32(struct mtd_info *mtd, loff_t from)
260{
261 size_t retlen;
262 __u32 ret;
263 int res;
264
265 res = MTD_READ(mtd, from, 4, &retlen, (unsigned char *)&ret);
266 if (retlen != 4) {
267 printk("Didn't read all bytes in flash_read_u32(). Returned %d\n", res);
268 return 0;
269 }
270
271 return ret;
272}
273
274
275static int
276flash_safe_write(struct mtd_info *mtd, loff_t to,
277 const u_char *buf, size_t count)
278{
279 size_t retlen;
280 int res;
281
282 D3(printk(KERN_NOTICE "flash_safe_write(%p, %08x, %p, %08x)\n",
283 mtd, (unsigned int) to, buf, count));
284
285 res = MTD_WRITE(mtd, to, count, &retlen, buf);
286 if (retlen != count) {
287 printk("Didn't write all bytes in flash_safe_write(). Returned %d\n", res);
288 }
289 return res?res:retlen;
290}
291
292
293static int
294flash_safe_writev(struct mtd_info *mtd, const struct kvec *vecs,
295 unsigned long iovec_cnt, loff_t to)
296{
297 size_t retlen, retlen_a;
298 int i;
299 int res;
300
301 D3(printk(KERN_NOTICE "flash_safe_writev(%p, %08x, %p)\n",
302 mtd, (unsigned int) to, vecs));
303
304 if (mtd->writev) {
305 res = MTD_WRITEV(mtd, vecs, iovec_cnt, to, &retlen);
306 return res ? res : retlen;
307 }
308 /* Not implemented writev. Repeatedly use write - on the not so
309 unreasonable assumption that the mtd driver doesn't care how
310 many write cycles we use. */
311 res=0;
312 retlen=0;
313
314 for (i=0; !res && i<iovec_cnt; i++) {
315 res = MTD_WRITE(mtd, to, vecs[i].iov_len, &retlen_a, vecs[i].iov_base);
316 if (retlen_a != vecs[i].iov_len) {
317 printk("Didn't write all bytes in flash_safe_writev(). Returned %d\n", res);
318 if (i != iovec_cnt-1)
319 return -EIO;
320 }
321 /* If res is non-zero, retlen_a is undefined, but we don't
322 care because in that case it's not going to be
323 returned anyway.
324 */
325 to += retlen_a;
326 retlen += retlen_a;
327 }
328 return res?res:retlen;
329}
330
331
332static int
333flash_memset(struct mtd_info *mtd, loff_t to,
334 const u_char c, size_t size)
335{
336 static unsigned char pattern[64];
337 int i;
338
339 /* fill up pattern */
340
341 for(i = 0; i < 64; i++)
342 pattern[i] = c;
343
344 /* write as many 64-byte chunks as we can */
345
346 while (size >= 64) {
347 flash_safe_write(mtd, to, pattern, 64);
348 size -= 64;
349 to += 64;
350 }
351
352 /* and the rest */
353
354 if(size)
355 flash_safe_write(mtd, to, pattern, size);
356
357 return size;
358}
359
360
361static void
362intrep_erase_callback(struct erase_info *done)
363{
364 wait_queue_head_t *wait_q;
365
366 wait_q = (wait_queue_head_t *)done->priv;
367
368 wake_up(wait_q);
369}
370
371
372static int
373flash_erase_region(struct mtd_info *mtd, loff_t start,
374 size_t size)
375{
376 struct erase_info *erase;
377 DECLARE_WAITQUEUE(wait, current);
378 wait_queue_head_t wait_q;
379
380 erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
381 if (!erase)
382 return -ENOMEM;
383
384 init_waitqueue_head(&wait_q);
385
386 erase->mtd = mtd;
387 erase->callback = intrep_erase_callback;
388 erase->addr = start;
389 erase->len = size;
390 erase->priv = (u_long)&wait_q;
391
392 /* FIXME: Use TASK_INTERRUPTIBLE and deal with being interrupted */
393 set_current_state(TASK_UNINTERRUPTIBLE);
394 add_wait_queue(&wait_q, &wait);
395
396 if (MTD_ERASE(mtd, erase) < 0) {
397 set_current_state(TASK_RUNNING);
398 remove_wait_queue(&wait_q, &wait);
399 kfree(erase);
400
401 printk(KERN_WARNING "flash: erase of region [0x%lx, 0x%lx] "
402 "totally failed\n", (long)start, (long)start + size);
403
404 return -1;
405 }
406
407 schedule(); /* Wait for flash to finish. */
408 remove_wait_queue(&wait_q, &wait);
409
410 kfree(erase);
411
412 return 0;
413}
414
415/* This routine calculates checksums in JFFS. */
416static __u32
417jffs_checksum(const void *data, int size)
418{
419 __u32 sum = 0;
420 __u8 *ptr = (__u8 *)data;
421 while (size-- > 0) {
422 sum += *ptr++;
423 }
424 D3(printk(", result: 0x%08x\n", sum));
425 return sum;
426}
427
428
429static int
430jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size, __u32 *result)
431{
432 __u32 sum = 0;
433 loff_t ptr = start;
434 __u8 *read_buf;
435 int i, length;
436
437 /* Allocate read buffer */
438 read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
439 if (!read_buf) {
440 printk(KERN_NOTICE "kmalloc failed in jffs_checksum_flash()\n");
441 return -ENOMEM;
442 }
443 /* Loop until checksum done */
444 while (size) {
445 /* Get amount of data to read */
446 if (size < 4096)
447 length = size;
448 else
449 length = 4096;
450
451 /* Perform flash read */
452 D3(printk(KERN_NOTICE "jffs_checksum_flash\n"));
453 flash_safe_read(mtd, ptr, &read_buf[0], length);
454
455 /* Compute checksum */
456 for (i=0; i < length ; i++)
457 sum += read_buf[i];
458
459 /* Update pointer and size */
460 size -= length;
461 ptr += length;
462 }
463
464 /* Free read buffer */
465 kfree (read_buf);
466
467 /* Return result */
468 D3(printk("checksum result: 0x%08x\n", sum));
469 *result = sum;
470 return 0;
471}
472
473static __inline__ void jffs_fm_write_lock(struct jffs_fmcontrol *fmc)
474{
475 // down(&fmc->wlock);
476}
477
478static __inline__ void jffs_fm_write_unlock(struct jffs_fmcontrol *fmc)
479{
480 // up(&fmc->wlock);
481}
482
483
484/* Create and initialize a new struct jffs_file. */
485static struct jffs_file *
486jffs_create_file(struct jffs_control *c,
487 const struct jffs_raw_inode *raw_inode)
488{
489 struct jffs_file *f;
490
491 if (!(f = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
492 GFP_KERNEL))) {
493 D(printk("jffs_create_file(): Failed!\n"));
494 return NULL;
495 }
496 no_jffs_file++;
497 memset(f, 0, sizeof(struct jffs_file));
498 f->ino = raw_inode->ino;
499 f->pino = raw_inode->pino;
500 f->nlink = raw_inode->nlink;
501 f->deleted = raw_inode->deleted;
502 f->c = c;
503
504 return f;
505}
506
507
508/* Build a control block for the file system. */
509static struct jffs_control *
510jffs_create_control(struct super_block *sb)
511{
512 struct jffs_control *c;
513 register int s = sizeof(struct jffs_control);
514 int i;
515 D(char *t = 0);
516
517 D2(printk("jffs_create_control()\n"));
518
519 if (!(c = (struct jffs_control *)kmalloc(s, GFP_KERNEL))) {
520 goto fail_control;
521 }
522 DJM(no_jffs_control++);
523 c->root = NULL;
524 c->gc_task = NULL;
525 c->hash_len = JFFS_HASH_SIZE;
526 s = sizeof(struct list_head) * c->hash_len;
527 if (!(c->hash = (struct list_head *)kmalloc(s, GFP_KERNEL))) {
528 goto fail_hash;
529 }
530 DJM(no_hash++);
531 for (i = 0; i < c->hash_len; i++)
532 INIT_LIST_HEAD(&c->hash[i]);
533 if (!(c->fmc = jffs_build_begin(c, MINOR(sb->s_dev)))) {
534 goto fail_fminit;
535 }
536 c->next_ino = JFFS_MIN_INO + 1;
537 c->delete_list = (struct jffs_delete_list *) 0;
538 return c;
539
540fail_fminit:
541 D(t = "c->fmc");
542fail_hash:
543 kfree(c);
544 DJM(no_jffs_control--);
545 D(t = t ? t : "c->hash");
546fail_control:
547 D(t = t ? t : "control");
548 D(printk("jffs_create_control(): Allocation failed: (%s)\n", t));
549 return (struct jffs_control *)0;
550}
551
552
553/* Clean up all data structures associated with the file system. */
554void
555jffs_cleanup_control(struct jffs_control *c)
556{
557 D2(printk("jffs_cleanup_control()\n"));
558
559 if (!c) {
560 D(printk("jffs_cleanup_control(): c == NULL !!!\n"));
561 return;
562 }
563
564 while (c->delete_list) {
565 struct jffs_delete_list *delete_list_element;
566 delete_list_element = c->delete_list;
567 c->delete_list = c->delete_list->next;
568 kfree(delete_list_element);
569 }
570
571 /* Free all files and nodes. */
572 if (c->hash) {
573 jffs_foreach_file(c, jffs_free_node_list);
574 jffs_foreach_file(c, jffs_free_file);
575 kfree(c->hash);
576 DJM(no_hash--);
577 }
578 jffs_cleanup_fmcontrol(c->fmc);
579 kfree(c);
580 DJM(no_jffs_control--);
581 D3(printk("jffs_cleanup_control(): Leaving...\n"));
582}
583
584
585/* This function adds a virtual root node to the in-RAM representation.
586 Called by jffs_build_fs(). */
587static int
588jffs_add_virtual_root(struct jffs_control *c)
589{
590 struct jffs_file *root;
591 struct jffs_node *node;
592
593 D2(printk("jffs_add_virtual_root(): "
594 "Creating a virtual root directory.\n"));
595
596 if (!(root = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
597 GFP_KERNEL))) {
598 return -ENOMEM;
599 }
600 no_jffs_file++;
601 if (!(node = jffs_alloc_node())) {
602 kfree(root);
603 no_jffs_file--;
604 return -ENOMEM;
605 }
606 DJM(no_jffs_node++);
607 memset(node, 0, sizeof(struct jffs_node));
608 node->ino = JFFS_MIN_INO;
609 memset(root, 0, sizeof(struct jffs_file));
610 root->ino = JFFS_MIN_INO;
611 root->mode = S_IFDIR | S_IRWXU | S_IRGRP
612 | S_IXGRP | S_IROTH | S_IXOTH;
613 root->atime = root->mtime = root->ctime = get_seconds();
614 root->nlink = 1;
615 root->c = c;
616 root->version_head = root->version_tail = node;
617 jffs_insert_file_into_hash(root);
618 return 0;
619}
620
621
622/* This is where the file system is built and initialized. */
623int
624jffs_build_fs(struct super_block *sb)
625{
626 struct jffs_control *c;
627 int err = 0;
628
629 D2(printk("jffs_build_fs()\n"));
630
631 if (!(c = jffs_create_control(sb))) {
632 return -ENOMEM;
633 }
634 c->building_fs = 1;
635 c->sb = sb;
636 if ((err = jffs_scan_flash(c)) < 0) {
637 if(err == -EAGAIN){
638 /* scan_flash() wants us to try once more. A flipping
639 bits sector was detect in the middle of the scan flash.
640 Clean up old allocated memory before going in.
641 */
642 D1(printk("jffs_build_fs: Cleaning up all control structures,"
643 " reallocating them and trying mount again.\n"));
644 jffs_cleanup_control(c);
645 if (!(c = jffs_create_control(sb))) {
646 return -ENOMEM;
647 }
648 c->building_fs = 1;
649 c->sb = sb;
650
651 if ((err = jffs_scan_flash(c)) < 0) {
652 goto jffs_build_fs_fail;
653 }
654 }else{
655 goto jffs_build_fs_fail;
656 }
657 }
658
659 /* Add a virtual root node if no one exists. */
660 if (!jffs_find_file(c, JFFS_MIN_INO)) {
661 if ((err = jffs_add_virtual_root(c)) < 0) {
662 goto jffs_build_fs_fail;
663 }
664 }
665
666 while (c->delete_list) {
667 struct jffs_file *f;
668 struct jffs_delete_list *delete_list_element;
669
670 if ((f = jffs_find_file(c, c->delete_list->ino))) {
671 f->deleted = 1;
672 }
673 delete_list_element = c->delete_list;
674 c->delete_list = c->delete_list->next;
675 kfree(delete_list_element);
676 }
677
678 /* Remove deleted nodes. */
679 if ((err = jffs_foreach_file(c, jffs_possibly_delete_file)) < 0) {
680 printk(KERN_ERR "JFFS: Failed to remove deleted nodes.\n");
681 goto jffs_build_fs_fail;
682 }
683 /* Remove redundant nodes. (We are not interested in the
684 return value in this case.) */
685 jffs_foreach_file(c, jffs_remove_redundant_nodes);
686 /* Try to build a tree from all the nodes. */
687 if ((err = jffs_foreach_file(c, jffs_insert_file_into_tree)) < 0) {
688 printk("JFFS: Failed to build tree.\n");
689 goto jffs_build_fs_fail;
690 }
691 /* Compute the sizes of all files in the filesystem. Adjust if
692 necessary. */
693 if ((err = jffs_foreach_file(c, jffs_build_file)) < 0) {
694 printk("JFFS: Failed to build file system.\n");
695 goto jffs_build_fs_fail;
696 }
697 sb->s_fs_info = (void *)c;
698 c->building_fs = 0;
699
700 D1(jffs_print_hash_table(c));
701 D1(jffs_print_tree(c->root, 0));
702
703 return 0;
704
705jffs_build_fs_fail:
706 jffs_cleanup_control(c);
707 return err;
708} /* jffs_build_fs() */
709
710
711/*
712 This checks for sectors that were being erased in their previous
713 lifetimes and for some reason or the other (power fail etc.),
714 the erase cycles never completed.
715 As the flash array would have reverted back to read status,
716 these sectors are detected by the symptom of the "flipping bits",
717 i.e. bits being read back differently from the same location in
718 flash if read multiple times.
719 The only solution to this is to re-erase the entire
720 sector.
721 Unfortunately detecting "flipping bits" is not a simple exercise
722 as a bit may be read back at 1 or 0 depending on the alignment
723 of the stars in the universe.
724 The level of confidence is in direct proportion to the number of
725 scans done. By power fail testing I (Vipin) have been able to
726 proove that reading twice is not enough.
727 Maybe 4 times? Change NUM_REREADS to a higher number if you want
728 a (even) higher degree of confidence in your mount process.
729 A higher number would of course slow down your mount.
730*/
731static int check_partly_erased_sectors(struct jffs_fmcontrol *fmc){
732
733#define NUM_REREADS 4 /* see note above */
734#define READ_AHEAD_BYTES 4096 /* must be a multiple of 4,
735 usually set to kernel page size */
736
737 __u8 *read_buf1;
738 __u8 *read_buf2;
739
740 int err = 0;
741 int retlen;
742 int i;
743 int cnt;
744 __u32 offset;
745 loff_t pos = 0;
746 loff_t end = fmc->flash_size;
747
748
749 /* Allocate read buffers */
750 read_buf1 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL);
751 if (!read_buf1)
752 return -ENOMEM;
753
754 read_buf2 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL);
755 if (!read_buf2) {
756 kfree(read_buf1);
757 return -ENOMEM;
758 }
759
760 CHECK_NEXT:
761 while(pos < end){
762
763 D1(printk("check_partly_erased_sector():checking sector which contains"
764 " offset 0x%x for flipping bits..\n", (__u32)pos));
765
766 retlen = flash_safe_read(fmc->mtd, pos,
767 &read_buf1[0], READ_AHEAD_BYTES);
768 retlen &= ~3;
769
770 for(cnt = 0; cnt < NUM_REREADS; cnt++){
771 (void)flash_safe_read(fmc->mtd, pos,
772 &read_buf2[0], READ_AHEAD_BYTES);
773
774 for (i=0 ; i < retlen ; i+=4) {
775 /* buffers MUST match, double word for word! */
776 if(*((__u32 *) &read_buf1[i]) !=
777 *((__u32 *) &read_buf2[i])
778 ){
779 /* flipping bits detected, time to erase sector */
780 /* This will help us log some statistics etc. */
781 D1(printk("Flipping bits detected in re-read round:%i of %i\n",
782 cnt, NUM_REREADS));
783 D1(printk("check_partly_erased_sectors:flipping bits detected"
784 " @offset:0x%x(0x%x!=0x%x)\n",
785 (__u32)pos+i, *((__u32 *) &read_buf1[i]),
786 *((__u32 *) &read_buf2[i])));
787
788 /* calculate start of present sector */
789 offset = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
790
791 D1(printk("check_partly_erased_sector():erasing sector starting 0x%x.\n",
792 offset));
793
794 if (flash_erase_region(fmc->mtd,
795 offset, fmc->sector_size) < 0) {
796 printk(KERN_ERR "JFFS: Erase of flash failed. "
797 "offset = %u, erase_size = %d\n",
798 offset , fmc->sector_size);
799
800 err = -EIO;
801 goto returnBack;
802
803 }else{
804 D1(printk("JFFS: Erase of flash sector @0x%x successful.\n",
805 offset));
806 /* skip ahead to the next sector */
807 pos = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
808 pos += fmc->sector_size;
809 goto CHECK_NEXT;
810 }
811 }
812 }
813 }
814 pos += READ_AHEAD_BYTES;
815 }
816
817 returnBack:
818 kfree(read_buf1);
819 kfree(read_buf2);
820
821 D2(printk("check_partly_erased_sector():Done checking all sectors till offset 0x%x for flipping bits.\n",
822 (__u32)pos));
823
824 return err;
825
826}/* end check_partly_erased_sectors() */
827
828
829
830/* Scan the whole flash memory in order to find all nodes in the
831 file systems. */
832static int
833jffs_scan_flash(struct jffs_control *c)
834{
835 char name[JFFS_MAX_NAME_LEN + 2];
836 struct jffs_raw_inode raw_inode;
837 struct jffs_node *node = NULL;
838 struct jffs_fmcontrol *fmc = c->fmc;
839 __u32 checksum;
840 __u8 tmp_accurate;
841 __u16 tmp_chksum;
842 __u32 deleted_file;
843 loff_t pos = 0;
844 loff_t start;
845 loff_t test_start;
846 loff_t end = fmc->flash_size;
847 __u8 *read_buf;
848 int i, len, retlen;
849 __u32 offset;
850
851 __u32 free_chunk_size1;
852 __u32 free_chunk_size2;
853
854
855#define NUMFREEALLOWED 2 /* 2 chunks of at least erase size space allowed */
856 int num_free_space = 0; /* Flag err if more than TWO
857 free blocks found. This is NOT allowed
858 by the current jffs design.
859 */
860 int num_free_spc_not_accp = 0; /* For debugging purposed keep count
861 of how much free space was rejected and
862 marked dirty
863 */
864
865 D1(printk("jffs_scan_flash(): start pos = 0x%lx, end = 0x%lx\n",
866 (long)pos, (long)end));
867
868 flash_safe_acquire(fmc->mtd);
869
870 /*
871 check and make sure that any sector does not suffer
872 from the "partly erased, bit flipping syndrome" (TM Vipin :)
873 If so, offending sectors will be erased.
874 */
875 if(check_partly_erased_sectors(fmc) < 0){
876
877 flash_safe_release(fmc->mtd);
878 return -EIO; /* bad, bad, bad error. Cannot continue.*/
879 }
880
881 /* Allocate read buffer */
882 read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
883 if (!read_buf) {
884 flash_safe_release(fmc->mtd);
885 return -ENOMEM;
886 }
887
888 /* Start the scan. */
889 while (pos < end) {
890 deleted_file = 0;
891
892 /* Remember the position from where we started this scan. */
893 start = pos;
894
895 switch (flash_read_u32(fmc->mtd, pos)) {
896 case JFFS_EMPTY_BITMASK:
897 /* We have found 0xffffffff at this position. We have to
898 scan the rest of the flash till the end or till
899 something else than 0xffffffff is found.
900 Keep going till we do not find JFFS_EMPTY_BITMASK
901 anymore */
902
903 D1(printk("jffs_scan_flash(): 0xffffffff at pos 0x%lx.\n",
904 (long)pos));
905
906 while(pos < end){
907
908 len = end - pos < 4096 ? end - pos : 4096;
909
910 retlen = flash_safe_read(fmc->mtd, pos,
911 &read_buf[0], len);
912
913 retlen &= ~3;
914
915 for (i=0 ; i < retlen ; i+=4, pos += 4) {
916 if(*((__u32 *) &read_buf[i]) !=
917 JFFS_EMPTY_BITMASK)
918 break;
919 }
920 if (i == retlen)
921 continue;
922 else
923 break;
924 }
925
926 D1(printk("jffs_scan_flash():0xffffffff ended at pos 0x%lx.\n",
927 (long)pos));
928
929 /* If some free space ends in the middle of a sector,
930 treat it as dirty rather than clean.
931 This is to handle the case where one thread
932 allocated space for a node, but didn't get to
933 actually _write_ it before power was lost, leaving
934 a gap in the log. Shifting all node writes into
935 a single kernel thread will fix the original problem.
936 */
937 if ((__u32) pos % fmc->sector_size) {
938 /* If there was free space in previous
939 sectors, don't mark that dirty too -
940 only from the beginning of this sector
941 (or from start)
942 */
943
944 test_start = pos & ~(fmc->sector_size-1); /* end of last sector */
945
946 if (start < test_start) {
947
948 /* free space started in the previous sector! */
949
950 if((num_free_space < NUMFREEALLOWED) &&
951 ((unsigned int)(test_start - start) >= fmc->sector_size)){
952
953 /*
954 Count it in if we are still under NUMFREEALLOWED *and* it is
955 at least 1 erase sector in length. This will keep us from
956 picking any little ole' space as "free".
957 */
958
959 D1(printk("Reducing end of free space to 0x%x from 0x%x\n",
960 (unsigned int)test_start, (unsigned int)pos));
961
962 D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n",
963 (unsigned int) start,
964 (unsigned int)(test_start - start)));
965
966 /* below, space from "start" to "pos" will be marked dirty. */
967 start = test_start;
968
969 /* Being in here means that we have found at least an entire
970 erase sector size of free space ending on a sector boundary.
971 Keep track of free spaces accepted.
972 */
973 num_free_space++;
974 }else{
975 num_free_spc_not_accp++;
976 D1(printk("Free space (#%i) found but *Not* accepted: Starting"
977 " 0x%x for 0x%x bytes\n",
978 num_free_spc_not_accp, (unsigned int)start,
979 (unsigned int)((unsigned int)(pos & ~(fmc->sector_size-1)) - (unsigned int)start)));
980
981 }
982
983 }
984 if((((__u32)(pos - start)) != 0)){
985
986 D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n",
987 (unsigned int) start, (unsigned int) (pos - start)));
988 jffs_fmalloced(fmc, (__u32) start,
989 (__u32) (pos - start), NULL);
990 }else{
991 /* "Flipping bits" detected. This means that our scan for them
992 did not catch this offset. See check_partly_erased_sectors() for
993 more info.
994 */
995
996 D1(printk("jffs_scan_flash():wants to allocate dirty flash "
997 "space for 0 bytes.\n"));
998 D1(printk("jffs_scan_flash(): Flipping bits! We will free "
999 "all allocated memory, erase this sector and remount\n"));
1000
1001 /* calculate start of present sector */
1002 offset = (((__u32)pos)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
1003
1004 D1(printk("jffs_scan_flash():erasing sector starting 0x%x.\n",
1005 offset));
1006
1007 if (flash_erase_region(fmc->mtd,
1008 offset, fmc->sector_size) < 0) {
1009 printk(KERN_ERR "JFFS: Erase of flash failed. "
1010 "offset = %u, erase_size = %d\n",
1011 offset , fmc->sector_size);
1012
1013 flash_safe_release(fmc->mtd);
1014 kfree (read_buf);
1015 return -1; /* bad, bad, bad! */
1016
1017 }
1018 flash_safe_release(fmc->mtd);
1019 kfree (read_buf);
1020
1021 return -EAGAIN; /* erased offending sector. Try mount one more time please. */
1022 }
1023 }else{
1024 /* Being in here means that we have found free space that ends on an erase sector
1025 boundary.
1026 Count it in if we are still under NUMFREEALLOWED *and* it is at least 1 erase
1027 sector in length. This will keep us from picking any little ole' space as "free".
1028 */
1029 if((num_free_space < NUMFREEALLOWED) &&
1030 ((unsigned int)(pos - start) >= fmc->sector_size)){
1031 /* We really don't do anything to mark space as free, except *not*
1032 mark it dirty and just advance the "pos" location pointer.
1033 It will automatically be picked up as free space.
1034 */
1035 num_free_space++;
1036 D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n",
1037 (unsigned int) start, (unsigned int) (pos - start)));
1038 }else{
1039 num_free_spc_not_accp++;
1040 D1(printk("Free space (#%i) found but *Not* accepted: Starting "
1041 "0x%x for 0x%x bytes\n", num_free_spc_not_accp,
1042 (unsigned int) start,
1043 (unsigned int) (pos - start)));
1044
1045 /* Mark this space as dirty. We already have our free space. */
1046 D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n",
1047 (unsigned int) start, (unsigned int) (pos - start)));
1048 jffs_fmalloced(fmc, (__u32) start,
1049 (__u32) (pos - start), NULL);
1050 }
1051
1052 }
1053 if(num_free_space > NUMFREEALLOWED){
1054 printk(KERN_WARNING "jffs_scan_flash(): Found free space "
1055 "number %i. Only %i free space is allowed.\n",
1056 num_free_space, NUMFREEALLOWED);
1057 }
1058 continue;
1059
1060 case JFFS_DIRTY_BITMASK:
1061 /* We have found 0x00000000 at this position. Scan as far
1062 as possible to find out how much is dirty. */
1063 D1(printk("jffs_scan_flash(): 0x00000000 at pos 0x%lx.\n",
1064 (long)pos));
1065 for (; pos < end
1066 && JFFS_DIRTY_BITMASK == flash_read_u32(fmc->mtd, pos);
1067 pos += 4);
1068 D1(printk("jffs_scan_flash(): 0x00 ended at "
1069 "pos 0x%lx.\n", (long)pos));
1070 jffs_fmalloced(fmc, (__u32) start,
1071 (__u32) (pos - start), NULL);
1072 continue;
1073
1074 case JFFS_MAGIC_BITMASK:
1075 /* We have probably found a new raw inode. */
1076 break;
1077
1078 default:
1079 bad_inode:
1080 /* We're f*cked. This is not solved yet. We have
1081 to scan for the magic pattern. */
1082 D1(printk("*************** Dirty flash memory or "
1083 "bad inode: "
1084 "hexdump(pos = 0x%lx, len = 128):\n",
1085 (long)pos));
1086 D1(jffs_hexdump(fmc->mtd, pos, 128));
1087
1088 for (pos += 4; pos < end; pos += 4) {
1089 switch (flash_read_u32(fmc->mtd, pos)) {
1090 case JFFS_MAGIC_BITMASK:
1091 case JFFS_EMPTY_BITMASK:
1092 /* handle these in the main switch() loop */
1093 goto cont_scan;
1094
1095 default:
1096 break;
1097 }
1098 }
1099
1100 cont_scan:
1101 /* First, mark as dirty the region
1102 which really does contain crap. */
1103 jffs_fmalloced(fmc, (__u32) start,
1104 (__u32) (pos - start),
1105 NULL);
1106
1107 continue;
1108 }/* switch */
1109
1110 /* We have found the beginning of an inode. Create a
1111 node for it unless there already is one available. */
1112 if (!node) {
1113 if (!(node = jffs_alloc_node())) {
1114 /* Free read buffer */
1115 kfree (read_buf);
1116
1117 /* Release the flash device */
1118 flash_safe_release(fmc->mtd);
1119
1120 return -ENOMEM;
1121 }
1122 DJM(no_jffs_node++);
1123 }
1124
1125 /* Read the next raw inode. */
1126
1127 flash_safe_read(fmc->mtd, pos, (u_char *) &raw_inode,
1128 sizeof(struct jffs_raw_inode));
1129
1130 /* When we compute the checksum for the inode, we never
1131 count the 'accurate' or the 'checksum' fields. */
1132 tmp_accurate = raw_inode.accurate;
1133 tmp_chksum = raw_inode.chksum;
1134 raw_inode.accurate = 0;
1135 raw_inode.chksum = 0;
1136 checksum = jffs_checksum(&raw_inode,
1137 sizeof(struct jffs_raw_inode));
1138 raw_inode.accurate = tmp_accurate;
1139 raw_inode.chksum = tmp_chksum;
1140
1141 D3(printk("*** We have found this raw inode at pos 0x%lx "
1142 "on the flash:\n", (long)pos));
1143 D3(jffs_print_raw_inode(&raw_inode));
1144
1145 if (checksum != raw_inode.chksum) {
1146 D1(printk("jffs_scan_flash(): Bad checksum: "
1147 "checksum = %u, "
1148 "raw_inode.chksum = %u\n",
1149 checksum, raw_inode.chksum));
1150 pos += sizeof(struct jffs_raw_inode);
1151 jffs_fmalloced(fmc, (__u32) start,
1152 (__u32) (pos - start), NULL);
1153 /* Reuse this unused struct jffs_node. */
1154 continue;
1155 }
1156
1157 /* Check the raw inode read so far. Start with the
1158 maximum length of the filename. */
1159 if (raw_inode.nsize > JFFS_MAX_NAME_LEN) {
1160 printk(KERN_WARNING "jffs_scan_flash: Found a "
1161 "JFFS node with name too large\n");
1162 goto bad_inode;
1163 }
1164
1165 if (raw_inode.rename && raw_inode.dsize != sizeof(__u32)) {
1166 printk(KERN_WARNING "jffs_scan_flash: Found a "
1167 "rename node with dsize %u.\n",
1168 raw_inode.dsize);
1169 jffs_print_raw_inode(&raw_inode);
1170 goto bad_inode;
1171 }
1172
1173 /* The node's data segment should not exceed a
1174 certain length. */
1175 if (raw_inode.dsize > fmc->max_chunk_size) {
1176 printk(KERN_WARNING "jffs_scan_flash: Found a "
1177 "JFFS node with dsize (0x%x) > max_chunk_size (0x%x)\n",
1178 raw_inode.dsize, fmc->max_chunk_size);
1179 goto bad_inode;
1180 }
1181
1182 pos += sizeof(struct jffs_raw_inode);
1183
1184 /* This shouldn't be necessary because a node that
1185 violates the flash boundaries shouldn't be written
1186 in the first place. */
1187 if (pos >= end) {
1188 goto check_node;
1189 }
1190
1191 /* Read the name. */
1192 *name = 0;
1193 if (raw_inode.nsize) {
1194 flash_safe_read(fmc->mtd, pos, name, raw_inode.nsize);
1195 name[raw_inode.nsize] = '\0';
1196 pos += raw_inode.nsize
1197 + JFFS_GET_PAD_BYTES(raw_inode.nsize);
1198 D3(printk("name == \"%s\"\n", name));
1199 checksum = jffs_checksum(name, raw_inode.nsize);
1200 if (checksum != raw_inode.nchksum) {
1201 D1(printk("jffs_scan_flash(): Bad checksum: "
1202 "checksum = %u, "
1203 "raw_inode.nchksum = %u\n",
1204 checksum, raw_inode.nchksum));
1205 jffs_fmalloced(fmc, (__u32) start,
1206 (__u32) (pos - start), NULL);
1207 /* Reuse this unused struct jffs_node. */
1208 continue;
1209 }
1210 if (pos >= end) {
1211 goto check_node;
1212 }
1213 }
1214
1215 /* Read the data, if it exists, in order to be sure it
1216 matches the checksum. */
1217 if (raw_inode.dsize) {
1218 if (raw_inode.rename) {
1219 deleted_file = flash_read_u32(fmc->mtd, pos);
1220 }
1221 if (jffs_checksum_flash(fmc->mtd, pos, raw_inode.dsize, &checksum)) {
1222 printk("jffs_checksum_flash() failed to calculate a checksum\n");
1223 jffs_fmalloced(fmc, (__u32) start,
1224 (__u32) (pos - start), NULL);
1225 /* Reuse this unused struct jffs_node. */
1226 continue;
1227 }
1228 pos += raw_inode.dsize
1229 + JFFS_GET_PAD_BYTES(raw_inode.dsize);
1230
1231 if (checksum != raw_inode.dchksum) {
1232 D1(printk("jffs_scan_flash(): Bad checksum: "
1233 "checksum = %u, "
1234 "raw_inode.dchksum = %u\n",
1235 checksum, raw_inode.dchksum));
1236 jffs_fmalloced(fmc, (__u32) start,
1237 (__u32) (pos - start), NULL);
1238 /* Reuse this unused struct jffs_node. */
1239 continue;
1240 }
1241 }
1242
1243 check_node:
1244
1245 /* Remember the highest inode number in the whole file
1246 system. This information will be used when assigning
1247 new files new inode numbers. */
1248 if (c->next_ino <= raw_inode.ino) {
1249 c->next_ino = raw_inode.ino + 1;
1250 }
1251
1252 if (raw_inode.accurate) {
1253 int err;
1254 node->data_offset = raw_inode.offset;
1255 node->data_size = raw_inode.dsize;
1256 node->removed_size = raw_inode.rsize;
1257 /* Compute the offset to the actual data in the
1258 on-flash node. */
1259 node->fm_offset
1260 = sizeof(struct jffs_raw_inode)
1261 + raw_inode.nsize
1262 + JFFS_GET_PAD_BYTES(raw_inode.nsize);
1263 node->fm = jffs_fmalloced(fmc, (__u32) start,
1264 (__u32) (pos - start),
1265 node);
1266 if (!node->fm) {
1267 D(printk("jffs_scan_flash(): !node->fm\n"));
1268 jffs_free_node(node);
1269 DJM(no_jffs_node--);
1270
1271 /* Free read buffer */
1272 kfree (read_buf);
1273
1274 /* Release the flash device */
1275 flash_safe_release(fmc->mtd);
1276
1277 return -ENOMEM;
1278 }
1279 if ((err = jffs_insert_node(c, NULL, &raw_inode,
1280 name, node)) < 0) {
1281 printk("JFFS: Failed to handle raw inode. "
1282 "(err = %d)\n", err);
1283 break;
1284 }
1285 if (raw_inode.rename) {
1286 struct jffs_delete_list *dl
1287 = (struct jffs_delete_list *)
1288 kmalloc(sizeof(struct jffs_delete_list),
1289 GFP_KERNEL);
1290 if (!dl) {
1291 D(printk("jffs_scan_flash: !dl\n"));
1292 jffs_free_node(node);
1293 DJM(no_jffs_node--);
1294
1295 /* Release the flash device */
1296 flash_safe_release(fmc->flash_part);
1297
1298 /* Free read buffer */
1299 kfree (read_buf);
1300
1301 return -ENOMEM;
1302 }
1303 dl->ino = deleted_file;
1304 dl->next = c->delete_list;
1305 c->delete_list = dl;
1306 node->data_size = 0;
1307 }
1308 D3(jffs_print_node(node));
1309 node = NULL; /* Don't free the node! */
1310 }
1311 else {
1312 jffs_fmalloced(fmc, (__u32) start,
1313 (__u32) (pos - start), NULL);
1314 D3(printk("jffs_scan_flash(): Just found an obsolete "
1315 "raw_inode. Continuing the scan...\n"));
1316 /* Reuse this unused struct jffs_node. */
1317 }
1318 }
1319
1320 if (node) {
1321 jffs_free_node(node);
1322 DJM(no_jffs_node--);
1323 }
1324 jffs_build_end(fmc);
1325
1326 /* Free read buffer */
1327 kfree (read_buf);
1328
1329 if(!num_free_space){
1330 printk(KERN_WARNING "jffs_scan_flash(): Did not find even a single "
1331 "chunk of free space. This is BAD!\n");
1332 }
1333
1334 /* Return happy */
1335 D3(printk("jffs_scan_flash(): Leaving...\n"));
1336 flash_safe_release(fmc->mtd);
1337
1338 /* This is to trap the "free size accounting screwed error. */
1339 free_chunk_size1 = jffs_free_size1(fmc);
1340 free_chunk_size2 = jffs_free_size2(fmc);
1341
1342 if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) {
1343
1344 printk(KERN_WARNING "jffs_scan_falsh():Free size accounting screwed\n");
1345 printk(KERN_WARNING "jfffs_scan_flash():free_chunk_size1 == 0x%x, "
1346 "free_chunk_size2 == 0x%x, fmc->free_size == 0x%x\n",
1347 free_chunk_size1, free_chunk_size2, fmc->free_size);
1348
1349 return -1; /* Do NOT mount f/s so that we can inspect what happened.
1350 Mounting this screwed up f/s will screw us up anyway.
1351 */
1352 }
1353
1354 return 0; /* as far as we are concerned, we are happy! */
1355} /* jffs_scan_flash() */
1356
1357
1358/* Insert any kind of node into the file system. Take care of data
1359 insertions and deletions. Also remove redundant information. The
1360 memory allocated for the `name' is regarded as "given away" in the
1361 caller's perspective. */
1362int
1363jffs_insert_node(struct jffs_control *c, struct jffs_file *f,
1364 const struct jffs_raw_inode *raw_inode,
1365 const char *name, struct jffs_node *node)
1366{
1367 int update_name = 0;
1368 int insert_into_tree = 0;
1369
1370 D2(printk("jffs_insert_node(): ino = %u, version = %u, "
1371 "name = \"%s\", deleted = %d\n",
1372 raw_inode->ino, raw_inode->version,
1373 ((name && *name) ? name : ""), raw_inode->deleted));
1374
1375 /* If there doesn't exist an associated jffs_file, then
1376 create, initialize and insert one into the file system. */
1377 if (!f && !(f = jffs_find_file(c, raw_inode->ino))) {
1378 if (!(f = jffs_create_file(c, raw_inode))) {
1379 return -ENOMEM;
1380 }
1381 jffs_insert_file_into_hash(f);
1382 insert_into_tree = 1;
1383 }
1384 node->ino = raw_inode->ino;
1385 node->version = raw_inode->version;
1386 node->data_size = raw_inode->dsize;
1387 node->fm_offset = sizeof(struct jffs_raw_inode) + raw_inode->nsize
1388 + JFFS_GET_PAD_BYTES(raw_inode->nsize);
1389 node->name_size = raw_inode->nsize;
1390
1391 /* Now insert the node at the correct position into the file's
1392 version list. */
1393 if (!f->version_head) {
1394 /* This is the first node. */
1395 f->version_head = node;
1396 f->version_tail = node;
1397 node->version_prev = NULL;
1398 node->version_next = NULL;
1399 f->highest_version = node->version;
1400 update_name = 1;
1401 f->mode = raw_inode->mode;
1402 f->uid = raw_inode->uid;
1403 f->gid = raw_inode->gid;
1404 f->atime = raw_inode->atime;
1405 f->mtime = raw_inode->mtime;
1406 f->ctime = raw_inode->ctime;
1407 }
1408 else if ((f->highest_version < node->version)
1409 || (node->version == 0)) {
1410 /* Insert at the end of the list. I.e. this node is the
1411 newest one so far. */
1412 node->version_prev = f->version_tail;
1413 node->version_next = NULL;
1414 f->version_tail->version_next = node;
1415 f->version_tail = node;
1416 f->highest_version = node->version;
1417 update_name = 1;
1418 f->pino = raw_inode->pino;
1419 f->mode = raw_inode->mode;
1420 f->uid = raw_inode->uid;
1421 f->gid = raw_inode->gid;
1422 f->atime = raw_inode->atime;
1423 f->mtime = raw_inode->mtime;
1424 f->ctime = raw_inode->ctime;
1425 }
1426 else if (f->version_head->version > node->version) {
1427 /* Insert at the bottom of the list. */
1428 node->version_prev = NULL;
1429 node->version_next = f->version_head;
1430 f->version_head->version_prev = node;
1431 f->version_head = node;
1432 if (!f->name) {
1433 update_name = 1;
1434 }
1435 }
1436 else {
1437 struct jffs_node *n;
1438 int newer_name = 0;
1439 /* Search for the insertion position starting from
1440 the tail (newest node). */
1441 for (n = f->version_tail; n; n = n->version_prev) {
1442 if (n->version < node->version) {
1443 node->version_prev = n;
1444 node->version_next = n->version_next;
1445 node->version_next->version_prev = node;
1446 n->version_next = node;
1447 if (!newer_name) {
1448 update_name = 1;
1449 }
1450 break;
1451 }
1452 if (n->name_size) {
1453 newer_name = 1;
1454 }
1455 }
1456 }
1457
1458 /* Deletion is irreversible. If any 'deleted' node is ever
1459 written, the file is deleted */
1460 if (raw_inode->deleted)
1461 f->deleted = raw_inode->deleted;
1462
1463 /* Perhaps update the name. */
1464 if (raw_inode->nsize && update_name && name && *name && (name != f->name)) {
1465 if (f->name) {
1466 kfree(f->name);
1467 DJM(no_name--);
1468 }
1469 if (!(f->name = (char *) kmalloc(raw_inode->nsize + 1,
1470 GFP_KERNEL))) {
1471 return -ENOMEM;
1472 }
1473 DJM(no_name++);
1474 memcpy(f->name, name, raw_inode->nsize);
1475 f->name[raw_inode->nsize] = '\0';
1476 f->nsize = raw_inode->nsize;
1477 D3(printk("jffs_insert_node(): Updated the name of "
1478 "the file to \"%s\".\n", name));
1479 }
1480
1481 if (!c->building_fs) {
1482 D3(printk("jffs_insert_node(): ---------------------------"
1483 "------------------------------------------- 1\n"));
1484 if (insert_into_tree) {
1485 jffs_insert_file_into_tree(f);
1486 }
1487 /* Once upon a time, we would call jffs_possibly_delete_file()
1488 here. That causes an oops if someone's still got the file
1489 open, so now we only do it in jffs_delete_inode()
1490 -- dwmw2
1491 */
1492 if (node->data_size || node->removed_size) {
1493 jffs_update_file(f, node);
1494 }
1495 jffs_remove_redundant_nodes(f);
1496
1497 jffs_garbage_collect_trigger(c);
1498
1499 D3(printk("jffs_insert_node(): ---------------------------"
1500 "------------------------------------------- 2\n"));
1501 }
1502
1503 return 0;
1504} /* jffs_insert_node() */
1505
1506
1507/* Unlink a jffs_node from the version list it is in. */
1508static inline void
1509jffs_unlink_node_from_version_list(struct jffs_file *f,
1510 struct jffs_node *node)
1511{
1512 if (node->version_prev) {
1513 node->version_prev->version_next = node->version_next;
1514 } else {
1515 f->version_head = node->version_next;
1516 }
1517 if (node->version_next) {
1518 node->version_next->version_prev = node->version_prev;
1519 } else {
1520 f->version_tail = node->version_prev;
1521 }
1522}
1523
1524
1525/* Unlink a jffs_node from the range list it is in. */
1526static inline void
1527jffs_unlink_node_from_range_list(struct jffs_file *f, struct jffs_node *node)
1528{
1529 if (node->range_prev) {
1530 node->range_prev->range_next = node->range_next;
1531 }
1532 else {
1533 f->range_head = node->range_next;
1534 }
1535 if (node->range_next) {
1536 node->range_next->range_prev = node->range_prev;
1537 }
1538 else {
1539 f->range_tail = node->range_prev;
1540 }
1541}
1542
1543
1544/* Function used by jffs_remove_redundant_nodes() below. This function
1545 classifies what kind of information a node adds to a file. */
1546static inline __u8
1547jffs_classify_node(struct jffs_node *node)
1548{
1549 __u8 mod_type = JFFS_MODIFY_INODE;
1550
1551 if (node->name_size) {
1552 mod_type |= JFFS_MODIFY_NAME;
1553 }
1554 if (node->data_size || node->removed_size) {
1555 mod_type |= JFFS_MODIFY_DATA;
1556 }
1557 return mod_type;
1558}
1559
1560
1561/* Remove redundant nodes from a file. Mark the on-flash memory
1562 as dirty. */
1563static int
1564jffs_remove_redundant_nodes(struct jffs_file *f)
1565{
1566 struct jffs_node *newest_node;
1567 struct jffs_node *cur;
1568 struct jffs_node *prev;
1569 __u8 newest_type;
1570 __u8 mod_type;
1571 __u8 node_with_name_later = 0;
1572
1573 if (!(newest_node = f->version_tail)) {
1574 return 0;
1575 }
1576
1577 /* What does the `newest_node' modify? */
1578 newest_type = jffs_classify_node(newest_node);
1579 node_with_name_later = newest_type & JFFS_MODIFY_NAME;
1580
1581 D3(printk("jffs_remove_redundant_nodes(): ino: %u, name: \"%s\", "
1582 "newest_type: %u\n", f->ino, (f->name ? f->name : ""),
1583 newest_type));
1584
1585 /* Traverse the file's nodes and determine which of them that are
1586 superfluous. Yeah, this might look very complex at first
1587 glance but it is actually very simple. */
1588 for (cur = newest_node->version_prev; cur; cur = prev) {
1589 prev = cur->version_prev;
1590 mod_type = jffs_classify_node(cur);
1591 if ((mod_type <= JFFS_MODIFY_INODE)
1592 || ((newest_type & JFFS_MODIFY_NAME)
1593 && (mod_type
1594 <= (JFFS_MODIFY_INODE + JFFS_MODIFY_NAME)))
1595 || (cur->data_size == 0 && cur->removed_size
1596 && !cur->version_prev && node_with_name_later)) {
1597 /* Yes, this node is redundant. Remove it. */
1598 D2(printk("jffs_remove_redundant_nodes(): "
1599 "Removing node: ino: %u, version: %u, "
1600 "mod_type: %u\n", cur->ino, cur->version,
1601 mod_type));
1602 jffs_unlink_node_from_version_list(f, cur);
1603 jffs_fmfree(f->c->fmc, cur->fm, cur);
1604 jffs_free_node(cur);
1605 DJM(no_jffs_node--);
1606 }
1607 else {
1608 node_with_name_later |= (mod_type & JFFS_MODIFY_NAME);
1609 }
1610 }
1611
1612 return 0;
1613}
1614
1615
1616/* Insert a file into the hash table. */
1617static int
1618jffs_insert_file_into_hash(struct jffs_file *f)
1619{
1620 int i = f->ino % f->c->hash_len;
1621
1622 D3(printk("jffs_insert_file_into_hash(): f->ino: %u\n", f->ino));
1623
1624 list_add(&f->hash, &f->c->hash[i]);
1625 return 0;
1626}
1627
1628
1629/* Insert a file into the file system tree. */
1630int
1631jffs_insert_file_into_tree(struct jffs_file *f)
1632{
1633 struct jffs_file *parent;
1634
1635 D3(printk("jffs_insert_file_into_tree(): name: \"%s\"\n",
1636 (f->name ? f->name : "")));
1637
1638 if (!(parent = jffs_find_file(f->c, f->pino))) {
1639 if (f->pino == 0) {
1640 f->c->root = f;
1641 f->parent = NULL;
1642 f->sibling_prev = NULL;
1643 f->sibling_next = NULL;
1644 return 0;
1645 }
1646 else {
1647 D1(printk("jffs_insert_file_into_tree(): Found "
1648 "inode with no parent and pino == %u\n",
1649 f->pino));
1650 return -1;
1651 }
1652 }
1653 f->parent = parent;
1654 f->sibling_next = parent->children;
1655 if (f->sibling_next) {
1656 f->sibling_next->sibling_prev = f;
1657 }
1658 f->sibling_prev = NULL;
1659 parent->children = f;
1660 return 0;
1661}
1662
1663
1664/* Remove a file from the hash table. */
1665static int
1666jffs_unlink_file_from_hash(struct jffs_file *f)
1667{
1668 D3(printk("jffs_unlink_file_from_hash(): f: 0x%p, "
1669 "ino %u\n", f, f->ino));
1670
1671 list_del(&f->hash);
1672 return 0;
1673}
1674
1675
1676/* Just remove the file from the parent's children. Don't free
1677 any memory. */
1678int
1679jffs_unlink_file_from_tree(struct jffs_file *f)
1680{
1681 D3(printk("jffs_unlink_file_from_tree(): ino: %d, pino: %d, name: "
1682 "\"%s\"\n", f->ino, f->pino, (f->name ? f->name : "")));
1683
1684 if (f->sibling_prev) {
1685 f->sibling_prev->sibling_next = f->sibling_next;
1686 }
1687 else if (f->parent) {
1688 D3(printk("f->parent=%p\n", f->parent));
1689 f->parent->children = f->sibling_next;
1690 }
1691 if (f->sibling_next) {
1692 f->sibling_next->sibling_prev = f->sibling_prev;
1693 }
1694 return 0;
1695}
1696
1697
1698/* Find a file with its inode number. */
1699struct jffs_file *
1700jffs_find_file(struct jffs_control *c, __u32 ino)
1701{
1702 struct jffs_file *f;
1703 int i = ino % c->hash_len;
1704 struct list_head *tmp;
1705
1706 D3(printk("jffs_find_file(): ino: %u\n", ino));
1707
1708 for (tmp = c->hash[i].next; tmp != &c->hash[i]; tmp = tmp->next) {
1709 f = list_entry(tmp, struct jffs_file, hash);
1710 if (ino != f->ino)
1711 continue;
1712 D3(printk("jffs_find_file(): Found file with ino "
1713 "%u. (name: \"%s\")\n",
1714 ino, (f->name ? f->name : ""));
1715 );
1716 return f;
1717 }
1718 D3(printk("jffs_find_file(): Didn't find file "
1719 "with ino %u.\n", ino);
1720 );
1721 return NULL;
1722}
1723
1724
1725/* Find a file in a directory. We are comparing the names. */
1726struct jffs_file *
1727jffs_find_child(struct jffs_file *dir, const char *name, int len)
1728{
1729 struct jffs_file *f;
1730
1731 D3(printk("jffs_find_child()\n"));
1732
1733 for (f = dir->children; f; f = f->sibling_next) {
1734 if (!f->deleted && f->name
1735 && !strncmp(f->name, name, len)
1736 && f->name[len] == '\0') {
1737 break;
1738 }
1739 }
1740
1741 D3(if (f) {
1742 printk("jffs_find_child(): Found \"%s\".\n", f->name);
1743 }
1744 else {
1745 char *copy = (char *) kmalloc(len + 1, GFP_KERNEL);
1746 if (copy) {
1747 memcpy(copy, name, len);
1748 copy[len] = '\0';
1749 }
1750 printk("jffs_find_child(): Didn't find the file \"%s\".\n",
1751 (copy ? copy : ""));
1752 if (copy) {
1753 kfree(copy);
1754 }
1755 });
1756
1757 return f;
1758}
1759
1760
1761/* Write a raw inode that takes up a certain amount of space in the flash
1762 memory. At the end of the flash device, there is often space that is
1763 impossible to use. At these times we want to mark this space as not
1764 used. In the cases when the amount of space is greater or equal than
1765 a struct jffs_raw_inode, we write a "dummy node" that takes up this
1766 space. The space after the raw inode, if it exists, is left as it is.
1767 Since this space after the raw inode contains JFFS_EMPTY_BITMASK bytes,
1768 we can compute the checksum of it; we don't have to manipulate it any
1769 further.
1770
1771 If the space left on the device is less than the size of a struct
1772 jffs_raw_inode, this space is filled with JFFS_DIRTY_BITMASK bytes.
1773 No raw inode is written this time. */
1774static int
1775jffs_write_dummy_node(struct jffs_control *c, struct jffs_fm *dirty_fm)
1776{
1777 struct jffs_fmcontrol *fmc = c->fmc;
1778 int err;
1779
1780 D1(printk("jffs_write_dummy_node(): dirty_fm->offset = 0x%08x, "
1781 "dirty_fm->size = %u\n",
1782 dirty_fm->offset, dirty_fm->size));
1783
1784 if (dirty_fm->size >= sizeof(struct jffs_raw_inode)) {
1785 struct jffs_raw_inode raw_inode;
1786 memset(&raw_inode, 0, sizeof(struct jffs_raw_inode));
1787 raw_inode.magic = JFFS_MAGIC_BITMASK;
1788 raw_inode.dsize = dirty_fm->size
1789 - sizeof(struct jffs_raw_inode);
1790 raw_inode.dchksum = raw_inode.dsize * 0xff;
1791 raw_inode.chksum
1792 = jffs_checksum(&raw_inode, sizeof(struct jffs_raw_inode));
1793
1794 if ((err = flash_safe_write(fmc->mtd,
1795 dirty_fm->offset,
1796 (u_char *)&raw_inode,
1797 sizeof(struct jffs_raw_inode)))
1798 < 0) {
1799 printk(KERN_ERR "JFFS: jffs_write_dummy_node: "
1800 "flash_safe_write failed!\n");
1801 return err;
1802 }
1803 }
1804 else {
1805 flash_safe_acquire(fmc->mtd);
1806 flash_memset(fmc->mtd, dirty_fm->offset, 0, dirty_fm->size);
1807 flash_safe_release(fmc->mtd);
1808 }
1809
1810 D3(printk("jffs_write_dummy_node(): Leaving...\n"));
1811 return 0;
1812}
1813
1814
1815/* Write a raw inode, possibly its name and possibly some data. */
1816int
1817jffs_write_node(struct jffs_control *c, struct jffs_node *node,
1818 struct jffs_raw_inode *raw_inode,
1819 const char *name, const unsigned char *data,
1820 int recoverable,
1821 struct jffs_file *f)
1822{
1823 struct jffs_fmcontrol *fmc = c->fmc;
1824 struct jffs_fm *fm;
1825 struct kvec node_iovec[4];
1826 unsigned long iovec_cnt;
1827
1828 __u32 pos;
1829 int err;
1830 __u32 slack = 0;
1831
1832 __u32 total_name_size = raw_inode->nsize
1833 + JFFS_GET_PAD_BYTES(raw_inode->nsize);
1834 __u32 total_data_size = raw_inode->dsize
1835 + JFFS_GET_PAD_BYTES(raw_inode->dsize);
1836 __u32 total_size = sizeof(struct jffs_raw_inode)
1837 + total_name_size + total_data_size;
1838
1839 /* If this node isn't something that will eventually let
1840 GC free even more space, then don't allow it unless
1841 there's at least max_chunk_size space still available
1842 */
1843 if (!recoverable)
1844 slack = fmc->max_chunk_size;
1845
1846
1847 /* Fire the retrorockets and shoot the fruiton torpedoes, sir! */
1848
1849 ASSERT(if (!node) {
1850 printk("jffs_write_node(): node == NULL\n");
1851 return -EINVAL;
1852 });
1853 ASSERT(if (raw_inode && raw_inode->nsize && !name) {
1854 printk("*** jffs_write_node(): nsize = %u but name == NULL\n",
1855 raw_inode->nsize);
1856 return -EINVAL;
1857 });
1858
1859 D1(printk("jffs_write_node(): filename = \"%s\", ino = %u, "
1860 "total_size = %u\n",
1861 (name ? name : ""), raw_inode->ino,
1862 total_size));
1863
1864 jffs_fm_write_lock(fmc);
1865
1866retry:
1867 fm = NULL;
1868 err = 0;
1869 while (!fm) {
1870
1871 /* Deadlocks suck. */
1872 while(fmc->free_size < fmc->min_free_size + total_size + slack) {
1873 jffs_fm_write_unlock(fmc);
1874 if (!JFFS_ENOUGH_SPACE(c, total_size + slack))
1875 return -ENOSPC;
1876 jffs_fm_write_lock(fmc);
1877 }
1878
1879 /* First try to allocate some flash memory. */
1880 err = jffs_fmalloc(fmc, total_size, node, &fm);
1881
1882 if (err == -ENOSPC) {
1883 /* Just out of space. GC and try again */
1884 if (fmc->dirty_size < fmc->sector_size) {
1885 D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) "
1886 "failed, no dirty space to GC\n", fmc,
1887 total_size));
1888 return err;
1889 }
1890
1891 D1(printk(KERN_INFO "jffs_write_node(): Calling jffs_garbage_collect_now()\n"));
1892 jffs_fm_write_unlock(fmc);
1893 if ((err = jffs_garbage_collect_now(c))) {
1894 D(printk("jffs_write_node(): jffs_garbage_collect_now() failed\n"));
1895 return err;
1896 }
1897 jffs_fm_write_lock(fmc);
1898 continue;
1899 }
1900
1901 if (err < 0) {
1902 jffs_fm_write_unlock(fmc);
1903
1904 D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) "
1905 "failed!\n", fmc, total_size));
1906 return err;
1907 }
1908
1909 if (!fm->nodes) {
1910 /* The jffs_fm struct that we got is not good enough.
1911 Make that space dirty and try again */
1912 if ((err = jffs_write_dummy_node(c, fm)) < 0) {
1913 kfree(fm);
1914 DJM(no_jffs_fm--);
1915 jffs_fm_write_unlock(fmc);
1916 D(printk("jffs_write_node(): "
1917 "jffs_write_dummy_node(): Failed!\n"));
1918 return err;
1919 }
1920 fm = NULL;
1921 }
1922 } /* while(!fm) */
1923 node->fm = fm;
1924
1925 ASSERT(if (fm->nodes == 0) {
1926 printk(KERN_ERR "jffs_write_node(): fm->nodes == 0\n");
1927 });
1928
1929 pos = node->fm->offset;
1930
1931 /* Increment the version number here. We can't let the caller
1932 set it beforehand, because we might have had to do GC on a node
1933 of this file - and we'd end up reusing version numbers.
1934 */
1935 if (f) {
1936 raw_inode->version = f->highest_version + 1;
1937 D1(printk (KERN_NOTICE "jffs_write_node(): setting version of %s to %d\n", f->name, raw_inode->version));
1938
1939 /* if the file was deleted, set the deleted bit in the raw inode */
1940 if (f->deleted)
1941 raw_inode->deleted = 1;
1942 }
1943
1944 /* Compute the checksum for the data and name chunks. */
1945 raw_inode->dchksum = jffs_checksum(data, raw_inode->dsize);
1946 raw_inode->nchksum = jffs_checksum(name, raw_inode->nsize);
1947
1948 /* The checksum is calculated without the chksum and accurate
1949 fields so set them to zero first. */
1950 raw_inode->accurate = 0;
1951 raw_inode->chksum = 0;
1952 raw_inode->chksum = jffs_checksum(raw_inode,
1953 sizeof(struct jffs_raw_inode));
1954 raw_inode->accurate = 0xff;
1955
1956 D3(printk("jffs_write_node(): About to write this raw inode to the "
1957 "flash at pos 0x%lx:\n", (long)pos));
1958 D3(jffs_print_raw_inode(raw_inode));
1959
1960 /* The actual raw JFFS node */
1961 node_iovec[0].iov_base = (void *) raw_inode;
1962 node_iovec[0].iov_len = (size_t) sizeof(struct jffs_raw_inode);
1963 iovec_cnt = 1;
1964
1965 /* Get name and size if there is one */
1966 if (raw_inode->nsize) {
1967 node_iovec[iovec_cnt].iov_base = (void *) name;
1968 node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->nsize;
1969 iovec_cnt++;
1970
1971 if (JFFS_GET_PAD_BYTES(raw_inode->nsize)) {
1972 static char allff[3]={255,255,255};
1973 /* Add some extra padding if necessary */
1974 node_iovec[iovec_cnt].iov_base = allff;
1975 node_iovec[iovec_cnt].iov_len =
1976 JFFS_GET_PAD_BYTES(raw_inode->nsize);
1977 iovec_cnt++;
1978 }
1979 }
1980
1981 /* Get data and size if there is any */
1982 if (raw_inode->dsize) {
1983 node_iovec[iovec_cnt].iov_base = (void *) data;
1984 node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->dsize;
1985 iovec_cnt++;
1986 /* No need to pad this because we're not actually putting
1987 anything after it.
1988 */
1989 }
1990
1991 if ((err = flash_safe_writev(fmc->mtd, node_iovec, iovec_cnt,
1992 pos)) < 0) {
1993 jffs_fmfree_partly(fmc, fm, 0);
1994 jffs_fm_write_unlock(fmc);
1995 printk(KERN_ERR "JFFS: jffs_write_node: Failed to write, "
1996 "requested %i, wrote %i\n", total_size, err);
1997 goto retry;
1998 }
1999 if (raw_inode->deleted)
2000 f->deleted = 1;
2001
2002 jffs_fm_write_unlock(fmc);
2003 D3(printk("jffs_write_node(): Leaving...\n"));
2004 return raw_inode->dsize;
2005} /* jffs_write_node() */
2006
2007
2008/* Read data from the node and write it to the buffer. 'node_offset'
2009 is how much we have read from this particular node before and which
2010 shouldn't be read again. 'max_size' is how much space there is in
2011 the buffer. */
2012static int
2013jffs_get_node_data(struct jffs_file *f, struct jffs_node *node,
2014 unsigned char *buf,__u32 node_offset, __u32 max_size)
2015{
2016 struct jffs_fmcontrol *fmc = f->c->fmc;
2017 __u32 pos = node->fm->offset + node->fm_offset + node_offset;
2018 __u32 avail = node->data_size - node_offset;
2019 __u32 r;
2020
2021 D2(printk(" jffs_get_node_data(): file: \"%s\", ino: %u, "
2022 "version: %u, node_offset: %u\n",
2023 f->name, node->ino, node->version, node_offset));
2024
2025 r = min(avail, max_size);
2026 D3(printk(KERN_NOTICE "jffs_get_node_data\n"));
2027 flash_safe_read(fmc->mtd, pos, buf, r);
2028
2029 D3(printk(" jffs_get_node_data(): Read %u byte%s.\n",
2030 r, (r == 1 ? "" : "s")));
2031
2032 return r;
2033}
2034
2035
2036/* Read data from the file's nodes. Write the data to the buffer
2037 'buf'. 'read_offset' tells how much data we should skip. */
2038int
2039jffs_read_data(struct jffs_file *f, unsigned char *buf, __u32 read_offset,
2040 __u32 size)
2041{
2042 struct jffs_node *node;
2043 __u32 read_data = 0; /* Total amount of read data. */
2044 __u32 node_offset = 0;
2045 __u32 pos = 0; /* Number of bytes traversed. */
2046
2047 D2(printk("jffs_read_data(): file = \"%s\", read_offset = %d, "
2048 "size = %u\n",
2049 (f->name ? f->name : ""), read_offset, size));
2050
2051 if (read_offset >= f->size) {
2052 D(printk(" f->size: %d\n", f->size));
2053 return 0;
2054 }
2055
2056 /* First find the node to read data from. */
2057 node = f->range_head;
2058 while (pos <= read_offset) {
2059 node_offset = read_offset - pos;
2060 if (node_offset >= node->data_size) {
2061 pos += node->data_size;
2062 node = node->range_next;
2063 }
2064 else {
2065 break;
2066 }
2067 }
2068
2069 /* "Cats are living proof that not everything in nature
2070 has to be useful."
2071 - Garrison Keilor ('97) */
2072
2073 /* Fill the buffer. */
2074 while (node && (read_data < size)) {
2075 int r;
2076 if (!node->fm) {
2077 /* This node does not refer to real data. */
2078 r = min(size - read_data,
2079 node->data_size - node_offset);
2080 memset(&buf[read_data], 0, r);
2081 }
2082 else if ((r = jffs_get_node_data(f, node, &buf[read_data],
2083 node_offset,
2084 size - read_data)) < 0) {
2085 return r;
2086 }
2087 read_data += r;
2088 node_offset = 0;
2089 node = node->range_next;
2090 }
2091 D3(printk(" jffs_read_data(): Read %u bytes.\n", read_data));
2092 return read_data;
2093}
2094
2095
2096/* Used for traversing all nodes in the hash table. */
2097int
2098jffs_foreach_file(struct jffs_control *c, int (*func)(struct jffs_file *))
2099{
2100 int pos;
2101 int r;
2102 int result = 0;
2103
2104 for (pos = 0; pos < c->hash_len; pos++) {
2105 struct list_head *p, *next;
2106 for (p = c->hash[pos].next; p != &c->hash[pos]; p = next) {
2107 /* We need a reference to the next file in the
2108 list because `func' might remove the current
2109 file `f'. */
2110 next = p->next;
2111 r = func(list_entry(p, struct jffs_file, hash));
2112 if (r < 0)
2113 return r;
2114 result += r;
2115 }
2116 }
2117
2118 return result;
2119}
2120
2121
2122/* Free all nodes associated with a file. */
2123static int
2124jffs_free_node_list(struct jffs_file *f)
2125{
2126 struct jffs_node *node;
2127 struct jffs_node *p;
2128
2129 D3(printk("jffs_free_node_list(): f #%u, \"%s\"\n",
2130 f->ino, (f->name ? f->name : "")));
2131 node = f->version_head;
2132 while (node) {
2133 p = node;
2134 node = node->version_next;
2135 jffs_free_node(p);
2136 DJM(no_jffs_node--);
2137 }
2138 return 0;
2139}
2140
2141
2142/* Free a file and its name. */
2143static int
2144jffs_free_file(struct jffs_file *f)
2145{
2146 D3(printk("jffs_free_file: f #%u, \"%s\"\n",
2147 f->ino, (f->name ? f->name : "")));
2148
2149 if (f->name) {
2150 kfree(f->name);
2151 DJM(no_name--);
2152 }
2153 kfree(f);
2154 no_jffs_file--;
2155 return 0;
2156}
2157
2158static long
2159jffs_get_file_count(void)
2160{
2161 return no_jffs_file;
2162}
2163
2164/* See if a file is deleted. If so, mark that file's nodes as obsolete. */
2165int
2166jffs_possibly_delete_file(struct jffs_file *f)
2167{
2168 struct jffs_node *n;
2169
2170 D3(printk("jffs_possibly_delete_file(): ino: %u\n",
2171 f->ino));
2172
2173 ASSERT(if (!f) {
2174 printk(KERN_ERR "jffs_possibly_delete_file(): f == NULL\n");
2175 return -1;
2176 });
2177
2178 if (f->deleted) {
2179 /* First try to remove all older versions. Commence with
2180 the oldest node. */
2181 for (n = f->version_head; n; n = n->version_next) {
2182 if (!n->fm) {
2183 continue;
2184 }
2185 if (jffs_fmfree(f->c->fmc, n->fm, n) < 0) {
2186 break;
2187 }
2188 }
2189 /* Unlink the file from the filesystem. */
2190 if (!f->c->building_fs) {
2191 jffs_unlink_file_from_tree(f);
2192 }
2193 jffs_unlink_file_from_hash(f);
2194 jffs_free_node_list(f);
2195 jffs_free_file(f);
2196 }
2197 return 0;
2198}
2199
2200
2201/* Used in conjunction with jffs_foreach_file() to count the number
2202 of files in the file system. */
2203int
2204jffs_file_count(struct jffs_file *f)
2205{
2206 return 1;
2207}
2208
2209
2210/* Build up a file's range list from scratch by going through the
2211 version list. */
2212static int
2213jffs_build_file(struct jffs_file *f)
2214{
2215 struct jffs_node *n;
2216
2217 D3(printk("jffs_build_file(): ino: %u, name: \"%s\"\n",
2218 f->ino, (f->name ? f->name : "")));
2219
2220 for (n = f->version_head; n; n = n->version_next) {
2221 jffs_update_file(f, n);
2222 }
2223 return 0;
2224}
2225
2226
2227/* Remove an amount of data from a file. If this amount of data is
2228 zero, that could mean that a node should be split in two parts.
2229 We remove or change the appropriate nodes in the lists.
2230
2231 Starting offset of area to be removed is node->data_offset,
2232 and the length of the area is in node->removed_size. */
2233static int
2234jffs_delete_data(struct jffs_file *f, struct jffs_node *node)
2235{
2236 struct jffs_node *n;
2237 __u32 offset = node->data_offset;
2238 __u32 remove_size = node->removed_size;
2239
2240 D3(printk("jffs_delete_data(): offset = %u, remove_size = %u\n",
2241 offset, remove_size));
2242
2243 if (remove_size == 0
2244 && f->range_tail
2245 && f->range_tail->data_offset + f->range_tail->data_size
2246 == offset) {
2247 /* A simple append; nothing to remove or no node to split. */
2248 return 0;
2249 }
2250
2251 /* Find the node where we should begin the removal. */
2252 for (n = f->range_head; n; n = n->range_next) {
2253 if (n->data_offset + n->data_size > offset) {
2254 break;
2255 }
2256 }
2257 if (!n) {
2258 /* If there's no data in the file there's no data to
2259 remove either. */
2260 return 0;
2261 }
2262
2263 if (n->data_offset > offset) {
2264 /* XXX: Not implemented yet. */
2265 printk(KERN_WARNING "JFFS: An unexpected situation "
2266 "occurred in jffs_delete_data.\n");
2267 }
2268 else if (n->data_offset < offset) {
2269 /* See if the node has to be split into two parts. */
2270 if (n->data_offset + n->data_size > offset + remove_size) {
2271 /* Do the split. */
2272 struct jffs_node *new_node;
2273 D3(printk("jffs_delete_data(): Split node with "
2274 "version number %u.\n", n->version));
2275
2276 if (!(new_node = jffs_alloc_node())) {
2277 D(printk("jffs_delete_data(): -ENOMEM\n"));
2278 return -ENOMEM;
2279 }
2280 DJM(no_jffs_node++);
2281
2282 new_node->ino = n->ino;
2283 new_node->version = n->version;
2284 new_node->data_offset = offset;
2285 new_node->data_size = n->data_size - (remove_size + (offset - n->data_offset));
2286 new_node->fm_offset = n->fm_offset + (remove_size + (offset - n->data_offset));
2287 new_node->name_size = n->name_size;
2288 new_node->fm = n->fm;
2289 new_node->version_prev = n;
2290 new_node->version_next = n->version_next;
2291 if (new_node->version_next) {
2292 new_node->version_next->version_prev
2293 = new_node;
2294 }
2295 else {
2296 f->version_tail = new_node;
2297 }
2298 n->version_next = new_node;
2299 new_node->range_prev = n;
2300 new_node->range_next = n->range_next;
2301 if (new_node->range_next) {
2302 new_node->range_next->range_prev = new_node;
2303 }
2304 else {
2305 f->range_tail = new_node;
2306 }
2307 /* A very interesting can of worms. */
2308 n->range_next = new_node;
2309 n->data_size = offset - n->data_offset;
2310 if (new_node->fm)
2311 jffs_add_node(new_node);
2312 else {
2313 D1(printk(KERN_WARNING "jffs_delete_data(): Splitting an empty node (file hold).\n!"));
2314 D1(printk(KERN_WARNING "FIXME: Did dwmw2 do the right thing here?\n"));
2315 }
2316 n = new_node->range_next;
2317 remove_size = 0;
2318 }
2319 else {
2320 /* No. No need to split the node. Just remove
2321 the end of the node. */
2322 int r = min(n->data_offset + n->data_size
2323 - offset, remove_size);
2324 n->data_size -= r;
2325 remove_size -= r;
2326 n = n->range_next;
2327 }
2328 }
2329
2330 /* Remove as many nodes as necessary. */
2331 while (n && remove_size) {
2332 if (n->data_size <= remove_size) {
2333 struct jffs_node *p = n;
2334 remove_size -= n->data_size;
2335 n = n->range_next;
2336 D3(printk("jffs_delete_data(): Removing node: "
2337 "ino: %u, version: %u%s\n",
2338 p->ino, p->version,
2339 (p->fm ? "" : " (virtual)")));
2340 if (p->fm) {
2341 jffs_fmfree(f->c->fmc, p->fm, p);
2342 }
2343 jffs_unlink_node_from_range_list(f, p);
2344 jffs_unlink_node_from_version_list(f, p);
2345 jffs_free_node(p);
2346 DJM(no_jffs_node--);
2347 }
2348 else {
2349 n->data_size -= remove_size;
2350 n->fm_offset += remove_size;
2351 n->data_offset -= (node->removed_size - remove_size);
2352 n = n->range_next;
2353 break;
2354 }
2355 }
2356
2357 /* Adjust the following nodes' information about offsets etc. */
2358 while (n && node->removed_size) {
2359 n->data_offset -= node->removed_size;
2360 n = n->range_next;
2361 }
2362
2363 if (node->removed_size > (f->size - node->data_offset)) {
2364 /* It's possible that the removed_size is in fact
2365 * greater than the amount of data we actually thought
2366 * were present in the first place - some of the nodes
2367 * which this node originally obsoleted may already have
2368 * been deleted from the flash by subsequent garbage
2369 * collection.
2370 *
2371 * If this is the case, don't let f->size go negative.
2372 * Bad things would happen :)
2373 */
2374 f->size = node->data_offset;
2375 } else {
2376 f->size -= node->removed_size;
2377 }
2378 D3(printk("jffs_delete_data(): f->size = %d\n", f->size));
2379 return 0;
2380} /* jffs_delete_data() */
2381
2382
2383/* Insert some data into a file. Prior to the call to this function,
2384 jffs_delete_data should be called. */
2385static int
2386jffs_insert_data(struct jffs_file *f, struct jffs_node *node)
2387{
2388 D3(printk("jffs_insert_data(): node->data_offset = %u, "
2389 "node->data_size = %u, f->size = %u\n",
2390 node->data_offset, node->data_size, f->size));
2391
2392 /* Find the position where we should insert data. */
2393 retry:
2394 if (node->data_offset == f->size) {
2395 /* A simple append. This is the most common operation. */
2396 node->range_next = NULL;
2397 node->range_prev = f->range_tail;
2398 if (node->range_prev) {
2399 node->range_prev->range_next = node;
2400 }
2401 f->range_tail = node;
2402 f->size += node->data_size;
2403 if (!f->range_head) {
2404 f->range_head = node;
2405 }
2406 }
2407 else if (node->data_offset < f->size) {
2408 /* Trying to insert data into the middle of the file. This
2409 means no problem because jffs_delete_data() has already
2410 prepared the range list for us. */
2411 struct jffs_node *n;
2412
2413 /* Find the correct place for the insertion and then insert
2414 the node. */
2415 for (n = f->range_head; n; n = n->range_next) {
2416 D2(printk("Cool stuff's happening!\n"));
2417
2418 if (n->data_offset == node->data_offset) {
2419 node->range_prev = n->range_prev;
2420 if (node->range_prev) {
2421 node->range_prev->range_next = node;
2422 }
2423 else {
2424 f->range_head = node;
2425 }
2426 node->range_next = n;
2427 n->range_prev = node;
2428 break;
2429 }
2430 ASSERT(else if (n->data_offset + n->data_size >
2431 node->data_offset) {
2432 printk(KERN_ERR "jffs_insert_data(): "
2433 "Couldn't find a place to insert "
2434 "the data!\n");
2435 return -1;
2436 });
2437 }
2438
2439 /* Adjust later nodes' offsets etc. */
2440 n = node->range_next;
2441 while (n) {
2442 n->data_offset += node->data_size;
2443 n = n->range_next;
2444 }
2445 f->size += node->data_size;
2446 }
2447 else if (node->data_offset > f->size) {
2448 /* Okay. This is tricky. This means that we want to insert
2449 data at a place that is beyond the limits of the file as
2450 it is constructed right now. This is actually a common
2451 event that for instance could occur during the mounting
2452 of the file system if a large file have been truncated,
2453 rewritten and then only partially garbage collected. */
2454
2455 struct jffs_node *n;
2456
2457 /* We need a place holder for the data that is missing in
2458 front of this insertion. This "virtual node" will not
2459 be associated with any space on the flash device. */
2460 struct jffs_node *virtual_node;
2461 if (!(virtual_node = jffs_alloc_node())) {
2462 return -ENOMEM;
2463 }
2464
2465 D(printk("jffs_insert_data: Inserting a virtual node.\n"));
2466 D(printk(" node->data_offset = %u\n", node->data_offset));
2467 D(printk(" f->size = %u\n", f->size));
2468
2469 virtual_node->ino = node->ino;
2470 virtual_node->version = node->version;
2471 virtual_node->removed_size = 0;
2472 virtual_node->fm_offset = 0;
2473 virtual_node->name_size = 0;
2474 virtual_node->fm = NULL; /* This is a virtual data holder. */
2475 virtual_node->version_prev = NULL;
2476 virtual_node->version_next = NULL;
2477 virtual_node->range_next = NULL;
2478
2479 /* Are there any data at all in the file yet? */
2480 if (f->range_head) {
2481 virtual_node->data_offset
2482 = f->range_tail->data_offset
2483 + f->range_tail->data_size;
2484 virtual_node->data_size
2485 = node->data_offset - virtual_node->data_offset;
2486 virtual_node->range_prev = f->range_tail;
2487 f->range_tail->range_next = virtual_node;
2488 }
2489 else {
2490 virtual_node->data_offset = 0;
2491 virtual_node->data_size = node->data_offset;
2492 virtual_node->range_prev = NULL;
2493 f->range_head = virtual_node;
2494 }
2495
2496 f->range_tail = virtual_node;
2497 f->size += virtual_node->data_size;
2498
2499 /* Insert this virtual node in the version list as well. */
2500 for (n = f->version_head; n ; n = n->version_next) {
2501 if (n->version == virtual_node->version) {
2502 virtual_node->version_prev = n->version_prev;
2503 n->version_prev = virtual_node;
2504 if (virtual_node->version_prev) {
2505 virtual_node->version_prev
2506 ->version_next = virtual_node;
2507 }
2508 else {
2509 f->version_head = virtual_node;
2510 }
2511 virtual_node->version_next = n;
2512 break;
2513 }
2514 }
2515
2516 D(jffs_print_node(virtual_node));
2517
2518 /* Make a new try to insert the node. */
2519 goto retry;
2520 }
2521
2522 D3(printk("jffs_insert_data(): f->size = %d\n", f->size));
2523 return 0;
2524}
2525
2526
2527/* A new node (with data) has been added to the file and now the range
2528 list has to be modified. */
2529static int
2530jffs_update_file(struct jffs_file *f, struct jffs_node *node)
2531{
2532 int err;
2533
2534 D3(printk("jffs_update_file(): ino: %u, version: %u\n",
2535 f->ino, node->version));
2536
2537 if (node->data_size == 0) {
2538 if (node->removed_size == 0) {
2539 /* data_offset == X */
2540 /* data_size == 0 */
2541 /* remove_size == 0 */
2542 }
2543 else {
2544 /* data_offset == X */
2545 /* data_size == 0 */
2546 /* remove_size != 0 */
2547 if ((err = jffs_delete_data(f, node)) < 0) {
2548 return err;
2549 }
2550 }
2551 }
2552 else {
2553 /* data_offset == X */
2554 /* data_size != 0 */
2555 /* remove_size == Y */
2556 if ((err = jffs_delete_data(f, node)) < 0) {
2557 return err;
2558 }
2559 if ((err = jffs_insert_data(f, node)) < 0) {
2560 return err;
2561 }
2562 }
2563 return 0;
2564}
2565
1da177e4
LT		 2566/* Print the contents of a file. */
2567#if 0
2568int
2569jffs_print_file(struct jffs_file *f)
2570{
2571 D(int i);
2572 D(printk("jffs_file: 0x%p\n", f));
2573 D(printk("{\n"));
2574 D(printk(" 0x%08x, /* ino */\n", f->ino));
2575 D(printk(" 0x%08x, /* pino */\n", f->pino));
2576 D(printk(" 0x%08x, /* mode */\n", f->mode));
2577 D(printk(" 0x%04x, /* uid */\n", f->uid));
2578 D(printk(" 0x%04x, /* gid */\n", f->gid));
2579 D(printk(" 0x%08x, /* atime */\n", f->atime));
2580 D(printk(" 0x%08x, /* mtime */\n", f->mtime));
2581 D(printk(" 0x%08x, /* ctime */\n", f->ctime));
2582 D(printk(" 0x%02x, /* nsize */\n", f->nsize));
2583 D(printk(" 0x%02x, /* nlink */\n", f->nlink));
2584 D(printk(" 0x%02x, /* deleted */\n", f->deleted));
2585 D(printk(" \"%s\", ", (f->name ? f->name : "")));
2586 D(for (i = strlen(f->name ? f->name : ""); i < 8; ++i) {
2587 printk(" ");
2588 });
2589 D(printk("/* name */\n"));
2590 D(printk(" 0x%08x, /* size */\n", f->size));
2591 D(printk(" 0x%08x, /* highest_version */\n",
2592 f->highest_version));
2593 D(printk(" 0x%p, /* c */\n", f->c));
2594 D(printk(" 0x%p, /* parent */\n", f->parent));
2595 D(printk(" 0x%p, /* children */\n", f->children));
2596 D(printk(" 0x%p, /* sibling_prev */\n", f->sibling_prev));
2597 D(printk(" 0x%p, /* sibling_next */\n", f->sibling_next));
2598 D(printk(" 0x%p, /* hash_prev */\n", f->hash.prev));
2599 D(printk(" 0x%p, /* hash_next */\n", f->hash.next));
2600 D(printk(" 0x%p, /* range_head */\n", f->range_head));
2601 D(printk(" 0x%p, /* range_tail */\n", f->range_tail));
2602 D(printk(" 0x%p, /* version_head */\n", f->version_head));
2603 D(printk(" 0x%p, /* version_tail */\n", f->version_tail));
2604 D(printk("}\n"));
2605 return 0;
2606}
2607#endif /* 0 */
2608
2609void
2610jffs_print_hash_table(struct jffs_control *c)
2611{
2612 int i;
2613
2614 printk("JFFS: Dumping the file system's hash table...\n");
2615 for (i = 0; i < c->hash_len; i++) {
2616 struct list_head *p;
2617 for (p = c->hash[i].next; p != &c->hash[i]; p = p->next) {
2618 struct jffs_file *f=list_entry(p,struct jffs_file,hash);
2619 printk("*** c->hash[%u]: \"%s\" "
2620 "(ino: %u, pino: %u)\n",
2621 i, (f->name ? f->name : ""),
2622 f->ino, f->pino);
2623 }
2624 }
2625}
2626
2627
2628void
2629jffs_print_tree(struct jffs_file *first_file, int indent)
2630{
2631 struct jffs_file *f;
2632 char *space;
2633 int dir;
2634
2635 if (!first_file) {
2636 return;
2637 }
2638
2639 if (!(space = (char *) kmalloc(indent + 1, GFP_KERNEL))) {
2640 printk("jffs_print_tree(): Out of memory!\n");
2641 return;
2642 }
2643
2644 memset(space, ' ', indent);
2645 space[indent] = '\0';
2646
2647 for (f = first_file; f; f = f->sibling_next) {
2648 dir = S_ISDIR(f->mode);
2649 printk("%s%s%s (ino: %u, highest_version: %u, size: %u)\n",
2650 space, (f->name ? f->name : ""), (dir ? "/" : ""),
2651 f->ino, f->highest_version, f->size);
2652 if (dir) {
2653 jffs_print_tree(f->children, indent + 2);
2654 }
2655 }
2656
2657 kfree(space);
2658}
2659
2660
2661#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
2662void
2663jffs_print_memory_allocation_statistics(void)
2664{
2665 static long printout;
2666 printk("________ Memory printout #%ld ________\n", ++printout);
2667 printk("no_jffs_file = %ld\n", no_jffs_file);
2668 printk("no_jffs_node = %ld\n", no_jffs_node);
2669 printk("no_jffs_control = %ld\n", no_jffs_control);
2670 printk("no_jffs_raw_inode = %ld\n", no_jffs_raw_inode);
2671 printk("no_jffs_node_ref = %ld\n", no_jffs_node_ref);
2672 printk("no_jffs_fm = %ld\n", no_jffs_fm);
2673 printk("no_jffs_fmcontrol = %ld\n", no_jffs_fmcontrol);
2674 printk("no_hash = %ld\n", no_hash);
2675 printk("no_name = %ld\n", no_name);
2676 printk("\n");
2677}
2678#endif
2679
2680
2681/* Rewrite `size' bytes, and begin at `node'. */
2682static int
2683jffs_rewrite_data(struct jffs_file *f, struct jffs_node *node, __u32 size)
2684{
2685 struct jffs_control *c = f->c;
2686 struct jffs_fmcontrol *fmc = c->fmc;
2687 struct jffs_raw_inode raw_inode;
2688 struct jffs_node *new_node;
2689 struct jffs_fm *fm;
2690 __u32 pos;
2691 __u32 pos_dchksum;
2692 __u32 total_name_size;
2693 __u32 total_data_size;
2694 __u32 total_size;
2695 int err;
2696
2697 D1(printk("***jffs_rewrite_data(): node: %u, name: \"%s\", size: %u\n",
2698 f->ino, (f->name ? f->name : "(null)"), size));
2699
2700 /* Create and initialize the new node. */
2701 if (!(new_node = jffs_alloc_node())) {
2702 D(printk("jffs_rewrite_data(): "
2703 "Failed to allocate node.\n"));
2704 return -ENOMEM;
2705 }
2706 DJM(no_jffs_node++);
2707 new_node->data_offset = node->data_offset;
2708 new_node->removed_size = size;
2709 total_name_size = JFFS_PAD(f->nsize);
2710 total_data_size = JFFS_PAD(size);
2711 total_size = sizeof(struct jffs_raw_inode)
2712 + total_name_size + total_data_size;
2713 new_node->fm_offset = sizeof(struct jffs_raw_inode)
2714 + total_name_size;
2715
2716retry:
2717 jffs_fm_write_lock(fmc);
2718 err = 0;
2719
2720 if ((err = jffs_fmalloc(fmc, total_size, new_node, &fm)) < 0) {
2721 DJM(no_jffs_node--);
2722 jffs_fm_write_unlock(fmc);
2723 D(printk("jffs_rewrite_data(): Failed to allocate fm.\n"));
2724 jffs_free_node(new_node);
2725 return err;
2726 }
2727 else if (!fm->nodes) {
2728 /* The jffs_fm struct that we got is not big enough. */
2729 /* This should never happen, because we deal with this case
2730 in jffs_garbage_collect_next().*/
2731 printk(KERN_WARNING "jffs_rewrite_data(): Allocated node is too small (%d bytes of %d)\n", fm->size, total_size);
2732 if ((err = jffs_write_dummy_node(c, fm)) < 0) {
2733 D(printk("jffs_rewrite_data(): "
2734 "jffs_write_dummy_node() Failed!\n"));
2735 } else {
2736 err = -ENOSPC;
2737 }
2738 DJM(no_jffs_fm--);
2739 jffs_fm_write_unlock(fmc);
2740 kfree(fm);
2741
2742 return err;
2743 }
2744 new_node->fm = fm;
2745
2746 /* Initialize the raw inode. */
2747 raw_inode.magic = JFFS_MAGIC_BITMASK;
2748 raw_inode.ino = f->ino;
2749 raw_inode.pino = f->pino;
2750 raw_inode.version = f->highest_version + 1;
2751 raw_inode.mode = f->mode;
2752 raw_inode.uid = f->uid;
2753 raw_inode.gid = f->gid;
2754 raw_inode.atime = f->atime;
2755 raw_inode.mtime = f->mtime;
2756 raw_inode.ctime = f->ctime;
2757 raw_inode.offset = node->data_offset;
2758 raw_inode.dsize = size;
2759 raw_inode.rsize = size;
2760 raw_inode.nsize = f->nsize;
2761 raw_inode.nlink = f->nlink;
2762 raw_inode.spare = 0;
2763 raw_inode.rename = 0;
2764 raw_inode.deleted = f->deleted;
2765 raw_inode.accurate = 0xff;
2766 raw_inode.dchksum = 0;
2767 raw_inode.nchksum = 0;
2768
2769 pos = new_node->fm->offset;
2770 pos_dchksum = pos +JFFS_RAW_INODE_DCHKSUM_OFFSET;
2771
2772 D3(printk("jffs_rewrite_data(): Writing this raw inode "
2773 "to pos 0x%ul.\n", pos));
2774 D3(jffs_print_raw_inode(&raw_inode));
2775
2776 if ((err = flash_safe_write(fmc->mtd, pos,
2777 (u_char *) &raw_inode,
2778 sizeof(struct jffs_raw_inode)
2779 - sizeof(__u32)
2780 - sizeof(__u16) - sizeof(__u16))) < 0) {
2781 jffs_fmfree_partly(fmc, fm,
2782 total_name_size + total_data_size);
2783 jffs_fm_write_unlock(fmc);
2784 printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
2785 "rewrite. (raw inode)\n");
2786 printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying "
2787 "rewrite. (raw inode)\n");
2788 goto retry;
2789 }
2790 pos += sizeof(struct jffs_raw_inode);
2791
2792 /* Write the name to the flash memory. */
2793 if (f->nsize) {
2794 D3(printk("jffs_rewrite_data(): Writing name \"%s\" to "
2795 "pos 0x%ul.\n", f->name, (unsigned int) pos));
2796 if ((err = flash_safe_write(fmc->mtd, pos,
2797 (u_char *)f->name,
2798 f->nsize)) < 0) {
2799 jffs_fmfree_partly(fmc, fm, total_data_size);
2800 jffs_fm_write_unlock(fmc);
2801 printk(KERN_ERR "JFFS: jffs_rewrite_data: Write "
2802 "error during rewrite. (name)\n");
2803 printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying "
2804 "rewrite. (name)\n");
2805 goto retry;
2806 }
2807 pos += total_name_size;
2808 raw_inode.nchksum = jffs_checksum(f->name, f->nsize);
2809 }
2810
2811 /* Write the data. */
2812 if (size) {
2813 int r;
2814 unsigned char *page;
2815 __u32 offset = node->data_offset;
2816
2817 if (!(page = (unsigned char *)__get_free_page(GFP_KERNEL))) {
2818 jffs_fmfree_partly(fmc, fm, 0);
2819 return -1;
2820 }
2821
2822 while (size) {
2823 __u32 s = min(size, (__u32)PAGE_SIZE);
2824 if ((r = jffs_read_data(f, (char *)page,
2825 offset, s)) < s) {
2826 free_page((unsigned long)page);
2827 jffs_fmfree_partly(fmc, fm, 0);
2828 jffs_fm_write_unlock(fmc);
2829 printk(KERN_ERR "JFFS: jffs_rewrite_data: "
2830 "jffs_read_data() "
2831 "failed! (r = %d)\n", r);
2832 return -1;
2833 }
2834 if ((err = flash_safe_write(fmc->mtd,
2835 pos, page, r)) < 0) {
2836 free_page((unsigned long)page);
2837 jffs_fmfree_partly(fmc, fm, 0);
2838 jffs_fm_write_unlock(fmc);
2839 printk(KERN_ERR "JFFS: jffs_rewrite_data: "
2840 "Write error during rewrite. "
2841 "(data)\n");
2842 goto retry;
2843 }
2844 pos += r;
2845 size -= r;
2846 offset += r;
2847 raw_inode.dchksum += jffs_checksum(page, r);
2848 }
2849
2850 free_page((unsigned long)page);
2851 }
2852
2853 raw_inode.accurate = 0;
2854 raw_inode.chksum = jffs_checksum(&raw_inode,
2855 sizeof(struct jffs_raw_inode)
2856 - sizeof(__u16));
2857
2858 /* Add the checksum. */
2859 if ((err
2860 = flash_safe_write(fmc->mtd, pos_dchksum,
2861 &((u_char *)
2862 &raw_inode)[JFFS_RAW_INODE_DCHKSUM_OFFSET],
2863 sizeof(__u32) + sizeof(__u16)
2864 + sizeof(__u16))) < 0) {
2865 jffs_fmfree_partly(fmc, fm, 0);
2866 jffs_fm_write_unlock(fmc);
2867 printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
2868 "rewrite. (checksum)\n");
2869 goto retry;
2870 }
2871
2872 /* Now make the file system aware of the newly written node. */
2873 jffs_insert_node(c, f, &raw_inode, f->name, new_node);
2874 jffs_fm_write_unlock(fmc);
2875
2876 D3(printk("jffs_rewrite_data(): Leaving...\n"));
2877 return 0;
2878} /* jffs_rewrite_data() */
2879
2880
2881/* jffs_garbage_collect_next implements one step in the garbage collect
2882 process and is often called multiple times at each occasion of a
2883 garbage collect. */
2884
2885static int
2886jffs_garbage_collect_next(struct jffs_control *c)
2887{
2888 struct jffs_fmcontrol *fmc = c->fmc;
2889 struct jffs_node *node;
2890 struct jffs_file *f;
2891 int err = 0;
2892 __u32 size;
2893 __u32 data_size;
2894 __u32 total_name_size;
2895 __u32 extra_available;
2896 __u32 space_needed;
2897 __u32 free_chunk_size1 = jffs_free_size1(fmc);
2898 D2(__u32 free_chunk_size2 = jffs_free_size2(fmc));
2899
2900 /* Get the oldest node in the flash. */
2901 node = jffs_get_oldest_node(fmc);
2902 ASSERT(if (!node) {
2903 printk(KERN_ERR "JFFS: jffs_garbage_collect_next: "
2904 "No oldest node found!\n");
2905 err = -1;
2906 goto jffs_garbage_collect_next_end;
2907
2908
2909 });
2910
2911 /* Find its corresponding file too. */
2912 f = jffs_find_file(c, node->ino);
2913
2914 if (!f) {
2915 printk (KERN_ERR "JFFS: jffs_garbage_collect_next: "
2916 "No file to garbage collect! "
2917 "(ino = 0x%08x)\n", node->ino);
2918 /* FIXME: Free the offending node and recover. */
2919 err = -1;
2920 goto jffs_garbage_collect_next_end;
2921 }
2922
2923 /* We always write out the name. Theoretically, we don't need
2924 to, but for now it's easier - because otherwise we'd have
2925 to keep track of how many times the current name exists on
2926 the flash and make sure it never reaches zero.
2927
2928 The current approach means that would be possible to cause
2929 the GC to end up eating its tail by writing lots of nodes
2930 with no name for it to garbage-collect. Hence the change in
2931 inode.c to write names with _every_ node.
2932
2933 It sucks, but it _should_ work.
2934 */
2935 total_name_size = JFFS_PAD(f->nsize);
2936
2937 D1(printk("jffs_garbage_collect_next(): \"%s\", "
2938 "ino: %u, version: %u, location 0x%x, dsize %u\n",
2939 (f->name ? f->name : ""), node->ino, node->version,
2940 node->fm->offset, node->data_size));
2941
2942 /* Compute how many data it's possible to rewrite at the moment. */
2943 data_size = f->size - node->data_offset;
2944
2945 /* And from that, the total size of the chunk we want to write */
2946 size = sizeof(struct jffs_raw_inode) + total_name_size
2947 + data_size + JFFS_GET_PAD_BYTES(data_size);
2948
2949 /* If that's more than max_chunk_size, reduce it accordingly */
2950 if (size > fmc->max_chunk_size) {
2951 size = fmc->max_chunk_size;
2952 data_size = size - sizeof(struct jffs_raw_inode)
2953 - total_name_size;
2954 }
2955
2956 /* If we're asking to take up more space than free_chunk_size1
2957 but we _could_ fit in it, shrink accordingly.
2958 */
2959 if (size > free_chunk_size1) {
2960
2961 if (free_chunk_size1 <
2962 (sizeof(struct jffs_raw_inode) + total_name_size + BLOCK_SIZE)){
2963 /* The space left is too small to be of any
2964 use really. */
2965 struct jffs_fm *dirty_fm
2966 = jffs_fmalloced(fmc,
2967 fmc->tail->offset + fmc->tail->size,
2968 free_chunk_size1, NULL);
2969 if (!dirty_fm) {
2970 printk(KERN_ERR "JFFS: "
2971 "jffs_garbage_collect_next: "
2972 "Failed to allocate `dirty' "
2973 "flash memory!\n");
2974 err = -1;
2975 goto jffs_garbage_collect_next_end;
2976 }
2977 D1(printk("Dirtying end of flash - too small\n"));
2978 jffs_write_dummy_node(c, dirty_fm);
2979 err = 0;
2980 goto jffs_garbage_collect_next_end;
2981 }
2982 D1(printk("Reducing size of new node from %d to %d to avoid "
2983 " exceeding free_chunk_size1\n",
2984 size, free_chunk_size1));
2985
2986 size = free_chunk_size1;
2987 data_size = size - sizeof(struct jffs_raw_inode)
2988 - total_name_size;
2989 }
2990
2991
2992 /* Calculate the amount of space needed to hold the nodes
2993 which are remaining in the tail */
2994 space_needed = fmc->min_free_size - (node->fm->offset % fmc->sector_size);
2995
2996 /* From that, calculate how much 'extra' space we can use to
2997 increase the size of the node we're writing from the size
2998 of the node we're obsoleting
2999 */
3000 if (space_needed > fmc->free_size) {
3001 /* If we've gone below min_free_size for some reason,
3002 don't fuck up. This is why we have
3003 min_free_size > sector_size. Whinge about it though,
3004 just so I can convince myself my maths is right.
3005 */
3006 D1(printk(KERN_WARNING "jffs_garbage_collect_next(): "
3007 "space_needed %d exceeded free_size %d\n",
3008 space_needed, fmc->free_size));
3009 extra_available = 0;
3010 } else {
3011 extra_available = fmc->free_size - space_needed;
3012 }
3013
3014 /* Check that we don't use up any more 'extra' space than
3015 what's available */
3016 if (size > JFFS_PAD(node->data_size) + total_name_size +
3017 sizeof(struct jffs_raw_inode) + extra_available) {
3018 D1(printk("Reducing size of new node from %d to %ld to avoid "
3019 "catching our tail\n", size,
3020 (long) (JFFS_PAD(node->data_size) + JFFS_PAD(node->name_size) +
3021 sizeof(struct jffs_raw_inode) + extra_available)));
3022 D1(printk("space_needed = %d, extra_available = %d\n",
3023 space_needed, extra_available));
3024
3025 size = JFFS_PAD(node->data_size) + total_name_size +
3026 sizeof(struct jffs_raw_inode) + extra_available;
3027 data_size = size - sizeof(struct jffs_raw_inode)
3028 - total_name_size;
3029 };
3030
3031 D2(printk(" total_name_size: %u\n", total_name_size));
3032 D2(printk(" data_size: %u\n", data_size));
3033 D2(printk(" size: %u\n", size));
3034 D2(printk(" f->nsize: %u\n", f->nsize));
3035 D2(printk(" f->size: %u\n", f->size));
3036 D2(printk(" node->data_offset: %u\n", node->data_offset));
3037 D2(printk(" free_chunk_size1: %u\n", free_chunk_size1));
3038 D2(printk(" free_chunk_size2: %u\n", free_chunk_size2));
3039 D2(printk(" node->fm->offset: 0x%08x\n", node->fm->offset));
3040
3041 if ((err = jffs_rewrite_data(f, node, data_size))) {
3042 printk(KERN_WARNING "jffs_rewrite_data() failed: %d\n", err);
3043 return err;
3044 }
3045
3046jffs_garbage_collect_next_end:
3047 D3(printk("jffs_garbage_collect_next: Leaving...\n"));
3048 return err;
3049} /* jffs_garbage_collect_next */
3050
3051
3052/* If an obsolete node is partly going to be erased due to garbage
3053 collection, the part that isn't going to be erased must be filled
3054 with zeroes so that the scan of the flash will work smoothly next
3055 time. (The data in the file could for instance be a JFFS image
3056 which could cause enormous confusion during a scan of the flash
3057 device if we didn't do this.)
3058 There are two phases in this procedure: First, the clearing of
3059 the name and data parts of the node. Second, possibly also clearing
3060 a part of the raw inode as well. If the box is power cycled during
3061 the first phase, only the checksum of this node-to-be-cleared-at-
3062 the-end will be wrong. If the box is power cycled during, or after,
3063 the clearing of the raw inode, the information like the length of
3064 the name and data parts are zeroed. The next time the box is
3065 powered up, the scanning algorithm manages this faulty data too
3066 because:
3067
3068 - The checksum is invalid and thus the raw inode must be discarded
3069 in any case.
3070 - If the lengths of the data part or the name part are zeroed, the
3071 scanning just continues after the raw inode. But after the inode
3072 the scanning procedure just finds zeroes which is the same as
3073 dirt.
3074
3075 So, in the end, this could never fail. :-) Even if it does fail,
3076 the scanning algorithm should manage that too. */
3077
3078static int
3079jffs_clear_end_of_node(struct jffs_control *c, __u32 erase_size)
3080{
3081 struct jffs_fm *fm;
3082 struct jffs_fmcontrol *fmc = c->fmc;
3083 __u32 zero_offset;
3084 __u32 zero_size;
3085 __u32 zero_offset_data;
3086 __u32 zero_size_data;
3087 __u32 cutting_raw_inode = 0;
3088
3089 if (!(fm = jffs_cut_node(fmc, erase_size))) {
3090 D3(printk("jffs_clear_end_of_node(): fm == NULL\n"));
3091 return 0;
3092 }
3093
3094 /* Where and how much shall we clear? */
3095 zero_offset = fmc->head->offset + erase_size;
3096 zero_size = fm->offset + fm->size - zero_offset;
3097
3098 /* Do we have to clear the raw_inode explicitly? */
3099 if (fm->size - zero_size < sizeof(struct jffs_raw_inode)) {
3100 cutting_raw_inode = sizeof(struct jffs_raw_inode)
3101 - (fm->size - zero_size);
3102 }
3103
3104 /* First, clear the name and data fields. */
3105 zero_offset_data = zero_offset + cutting_raw_inode;
3106 zero_size_data = zero_size - cutting_raw_inode;
3107 flash_safe_acquire(fmc->mtd);
3108 flash_memset(fmc->mtd, zero_offset_data, 0, zero_size_data);
3109 flash_safe_release(fmc->mtd);
3110
3111 /* Should we clear a part of the raw inode? */
3112 if (cutting_raw_inode) {
3113 /* I guess it is ok to clear the raw inode in this order. */
3114 flash_safe_acquire(fmc->mtd);
3115 flash_memset(fmc->mtd, zero_offset, 0,
3116 cutting_raw_inode);
3117 flash_safe_release(fmc->mtd);
3118 }
3119
3120 return 0;
3121} /* jffs_clear_end_of_node() */
3122
3123/* Try to erase as much as possible of the dirt in the flash memory. */
3124static long
3125jffs_try_to_erase(struct jffs_control *c)
3126{
3127 struct jffs_fmcontrol *fmc = c->fmc;
3128 long erase_size;
3129 int err;
3130 __u32 offset;
3131
3132 D3(printk("jffs_try_to_erase()\n"));
3133
3134 erase_size = jffs_erasable_size(fmc);
3135
3136 D2(printk("jffs_try_to_erase(): erase_size = %ld\n", erase_size));
3137
3138 if (erase_size == 0) {
3139 return 0;
3140 }
3141 else if (erase_size < 0) {
3142 printk(KERN_ERR "JFFS: jffs_try_to_erase: "
3143 "jffs_erasable_size returned %ld.\n", erase_size);
3144 return erase_size;
3145 }
3146
3147 if ((err = jffs_clear_end_of_node(c, erase_size)) < 0) {
3148 printk(KERN_ERR "JFFS: jffs_try_to_erase: "
3149 "Clearing of node failed.\n");
3150 return err;
3151 }
3152
3153 offset = fmc->head->offset;
3154
3155 /* Now, let's try to do the erase. */
3156 if ((err = flash_erase_region(fmc->mtd,
3157 offset, erase_size)) < 0) {
3158 printk(KERN_ERR "JFFS: Erase of flash failed. "
3159 "offset = %u, erase_size = %ld\n",
3160 offset, erase_size);
3161 /* XXX: Here we should allocate this area as dirty
3162 with jffs_fmalloced or something similar. Now
3163 we just report the error. */
3164 return err;
3165 }
3166
3167#if 0
3168 /* Check if the erased sectors really got erased. */
3169 {
3170 __u32 pos;
3171 __u32 end;
3172
3173 pos = (__u32)flash_get_direct_pointer(to_kdev_t(c->sb->s_dev), offset);
3174 end = pos + erase_size;
3175
3176 D2(printk("JFFS: Checking erased sector(s)...\n"));
3177
3178 flash_safe_acquire(fmc->mtd);
3179
3180 for (; pos < end; pos += 4) {
3181 if (*(__u32 *)pos != JFFS_EMPTY_BITMASK) {
3182 printk("JFFS: Erase failed! pos = 0x%lx\n",
3183 (long)pos);
3184 jffs_hexdump(fmc->mtd, pos,
3185 jffs_min(256, end - pos));
3186 err = -1;
3187 break;
3188 }
3189 }
3190
3191 flash_safe_release(fmc->mtd);
3192
3193 if (!err) {
3194 D2(printk("JFFS: Erase succeeded.\n"));
3195 }
3196 else {
3197 /* XXX: Here we should allocate the memory
3198 with jffs_fmalloced() in order to prevent
3199 JFFS from using this area accidentally. */
3200 return err;
3201 }
3202 }
3203#endif
3204
3205 /* Update the flash memory data structures. */
3206 jffs_sync_erase(fmc, erase_size);
3207
3208 return erase_size;
3209}
3210
3211
3212/* There are different criteria that should trigger a garbage collect:
3213
3214 1. There is too much dirt in the memory.
3215 2. The free space is becoming small.
3216 3. There are many versions of a node.
3217
3218 The garbage collect should always be done in a manner that guarantees
3219 that future garbage collects cannot be locked. E.g. Rewritten chunks
3220 should not be too large (span more than one sector in the flash memory
3221 for exemple). Of course there is a limit on how intelligent this garbage
3222 collection can be. */
3223
3224
3225static int
3226jffs_garbage_collect_now(struct jffs_control *c)
3227{
3228 struct jffs_fmcontrol *fmc = c->fmc;
3229 long erased = 0;
3230 int result = 0;
3231 D1(int i = 1);
3232 D2(printk("***jffs_garbage_collect_now(): fmc->dirty_size = %u, fmc->free_size = 0x%x\n, fcs1=0x%x, fcs2=0x%x",
3233 fmc->dirty_size, fmc->free_size, jffs_free_size1(fmc), jffs_free_size2(fmc)));
3234 D2(jffs_print_fmcontrol(fmc));
3235
3236 // down(&fmc->gclock);
3237
3238 /* If it is possible to garbage collect, do so. */
3239
3240 while (erased == 0) {
3241 D1(printk("***jffs_garbage_collect_now(): round #%u, "
3242 "fmc->dirty_size = %u\n", i++, fmc->dirty_size));
3243 D2(jffs_print_fmcontrol(fmc));
3244
3245 if ((erased = jffs_try_to_erase(c)) < 0) {
3246 printk(KERN_WARNING "JFFS: Error in "
3247 "garbage collector.\n");
3248 result = erased;
3249 goto gc_end;
3250 }
3251 if (erased)
3252 break;
3253
3254 if (fmc->free_size == 0) {
3255 /* Argh */
3256 printk(KERN_ERR "jffs_garbage_collect_now(): free_size == 0. This is BAD.\n");
3257 result = -ENOSPC;
3258 break;
3259 }
3260
3261 if (fmc->dirty_size < fmc->sector_size) {
3262 /* Actually, we _may_ have been able to free some,
3263 * if there are many overlapping nodes which aren't
3264 * actually marked dirty because they still have
3265 * some valid data in each.
3266 */
3267 result = -ENOSPC;
3268 break;
3269 }
3270
3271 /* Let's dare to make a garbage collect. */
3272 if ((result = jffs_garbage_collect_next(c)) < 0) {
3273 printk(KERN_ERR "JFFS: Something "
3274 "has gone seriously wrong "
3275 "with a garbage collect.\n");
3276 goto gc_end;
3277 }
3278
3279 D1(printk(" jffs_garbage_collect_now(): erased: %ld\n", erased));
3280 DJM(jffs_print_memory_allocation_statistics());
3281 }
3282
3283gc_end:
3284 // up(&fmc->gclock);
3285
3286 D3(printk(" jffs_garbage_collect_now(): Leaving...\n"));
3287 D1(if (erased) {
3288 printk("jffs_g_c_now(): erased = %ld\n", erased);
3289 jffs_print_fmcontrol(fmc);
3290 });
3291
3292 if (!erased && !result)
3293 return -ENOSPC;
3294
3295 return result;
3296} /* jffs_garbage_collect_now() */
3297
3298
3299/* Determine if it is reasonable to start garbage collection.
3300 We start a gc pass if either:
3301 - The number of free bytes < MIN_FREE_BYTES && at least one
3302 block is dirty, OR
3303 - The number of dirty bytes > MAX_DIRTY_BYTES
3304*/
3305static inline int thread_should_wake (struct jffs_control *c)
3306{
3307 D1(printk (KERN_NOTICE "thread_should_wake(): free=%d, dirty=%d, blocksize=%d.\n",
3308 c->fmc->free_size, c->fmc->dirty_size, c->fmc->sector_size));
3309
3310 /* If there's not enough dirty space to free a block, there's no point. */
3311 if (c->fmc->dirty_size < c->fmc->sector_size) {
3312 D2(printk(KERN_NOTICE "thread_should_wake(): Not waking. Insufficient dirty space\n"));
3313 return 0;
3314 }
3315#if 1
3316 /* If there is too much RAM used by the various structures, GC */
3317 if (jffs_get_node_inuse() > (c->fmc->used_size/c->fmc->max_chunk_size * 5 + jffs_get_file_count() * 2 + 50)) {
3318 /* FIXME: Provide proof that this test can be satisfied. We
3319 don't want a filesystem doing endless GC just because this
3320 condition cannot ever be false.
3321 */
3322 D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to number of nodes\n"));
3323 return 1;
3324 }
3325#endif
3326 /* If there are fewer free bytes than the threshold, GC */
3327 if (c->fmc->free_size < c->gc_minfree_threshold) {
3328 D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to insufficent free space\n"));
3329 return 1;
3330 }
3331 /* If there are more dirty bytes than the threshold, GC */
3332 if (c->fmc->dirty_size > c->gc_maxdirty_threshold) {
3333 D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to excessive dirty space\n"));
3334 return 1;
3335 }
3336 /* FIXME: What about the "There are many versions of a node" condition? */
3337
3338 return 0;
3339}
3340
3341
3342void jffs_garbage_collect_trigger(struct jffs_control *c)
3343{
3344 /* NOTE: We rely on the fact that we have the BKL here.
3345 * Otherwise, the gc_task could go away between the check
3346 * and the wake_up_process()
3347 */
3348 if (c->gc_task && thread_should_wake(c))
3349 send_sig(SIGHUP, c->gc_task, 1);
3350}
3351
3352
3353/* Kernel threads take (void *) as arguments. Thus we pass
3354 the jffs_control data as a (void *) and then cast it. */
3355int
3356jffs_garbage_collect_thread(void *ptr)
3357{
3358 struct jffs_control *c = (struct jffs_control *) ptr;
3359 struct jffs_fmcontrol *fmc = c->fmc;
3360 long erased;
3361 int result = 0;
3362 D1(int i = 1);
3363
3364 daemonize("jffs_gcd");
3365
3366 c->gc_task = current;
3367
3368 lock_kernel();
3369 init_completion(&c->gc_thread_comp); /* barrier */
3370 spin_lock_irq(&current->sighand->siglock);
3371 siginitsetinv (&current->blocked, sigmask(SIGHUP) | sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT));
3372 recalc_sigpending();
3373 spin_unlock_irq(&current->sighand->siglock);
3374
3375 D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): Starting infinite loop.\n"));
3376
3377 for (;;) {
3378
3379 /* See if we need to start gc. If we don't, go to sleep.
3380
3381 Current implementation is a BAD THING(tm). If we try
3382 to unmount the FS, the unmount operation will sleep waiting
3383 for this thread to exit. We need to arrange to send it a
3384 sig before the umount process sleeps.
3385 */
3386
3387 if (!thread_should_wake(c))
3388 set_current_state (TASK_INTERRUPTIBLE);
3389
3390 schedule(); /* Yes, we do this even if we want to go
3391 on immediately - we're a low priority
3392 background task. */
3393
3394 /* Put_super will send a SIGKILL and then wait on the sem.
3395 */
3396 while (signal_pending(current)) {
3397 siginfo_t info;
3398 unsigned long signr = 0;
3399
ef2a701d
NC		 3400 if (try_to_freeze())
3401 continue;
3402
1da177e4
LT		 3403 spin_lock_irq(&current->sighand->siglock);
3404 signr = dequeue_signal(current, &current->blocked, &info);
3405 spin_unlock_irq(&current->sighand->siglock);
3406
3407 switch(signr) {
3408 case SIGSTOP:
3409 D1(printk("jffs_garbage_collect_thread(): SIGSTOP received.\n"));
3410 set_current_state(TASK_STOPPED);
3411 schedule();
3412 break;
3413
3414 case SIGKILL:
3415 D1(printk("jffs_garbage_collect_thread(): SIGKILL received.\n"));
3416 c->gc_task = NULL;
3417 complete_and_exit(&c->gc_thread_comp, 0);
3418 }
3419 }
3420
3421
3422 D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): collecting.\n"));
3423
3424 D3(printk (KERN_NOTICE "g_c_thread(): down biglock\n"));
3425 down(&fmc->biglock);
3426
3427 D1(printk("***jffs_garbage_collect_thread(): round #%u, "
3428 "fmc->dirty_size = %u\n", i++, fmc->dirty_size));
3429 D2(jffs_print_fmcontrol(fmc));
3430
3431 if ((erased = jffs_try_to_erase(c)) < 0) {
3432 printk(KERN_WARNING "JFFS: Error in "
3433 "garbage collector: %ld.\n", erased);
3434 }
3435
3436 if (erased)
3437 goto gc_end;
3438
3439 if (fmc->free_size == 0) {
3440 /* Argh. Might as well commit suicide. */
3441 printk(KERN_ERR "jffs_garbage_collect_thread(): free_size == 0. This is BAD.\n");
3442 send_sig(SIGQUIT, c->gc_task, 1);
3443 // panic()
3444 goto gc_end;
3445 }
3446
3447 /* Let's dare to make a garbage collect. */
3448 if ((result = jffs_garbage_collect_next(c)) < 0) {
3449 printk(KERN_ERR "JFFS: Something "
3450 "has gone seriously wrong "
3451 "with a garbage collect: %d\n", result);
3452 }
3453
3454 gc_end:
3455 D3(printk (KERN_NOTICE "g_c_thread(): up biglock\n"));
3456 up(&fmc->biglock);
3457 } /* for (;;) */
3458} /* jffs_garbage_collect_thread() */
Linux kernel - Deliverables
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