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