backport jffs2 eofdetect patch to linux 2.4
[openwrt-10.03/.git] / target / linux / generic-2.4 / patches / 227-jffs2_eofdetect.patch
1 diff -ur linux.old/fs/jffs2/scan.c linux.dev/fs/jffs2/scan.c
2 --- linux.old/fs/jffs2/scan.c   2003-11-28 19:26:21.000000000 +0100
3 +++ linux.dev/fs/jffs2/scan.c   2006-06-22 00:29:02.000000000 +0200
4 @@ -31,6 +31,10 @@
5   * provisions above, a recipient may use your version of this file
6   * under either the RHEPL or the GPL.
7   *
8 + * Modification for automatically cleaning the filesystem after
9 + * a specially marked block
10 + * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
11 + *
12   * $Id: scan.c,v 1.51.2.4 2003/11/02 13:51:18 dwmw2 Exp $
13   *
14   */
15 @@ -88,7 +92,12 @@
16         for (i=0; i<c->nr_blocks; i++) {
17                 struct jffs2_eraseblock *jeb = &c->blocks[i];
18  
19 -               ret = jffs2_scan_eraseblock(c, jeb);
20 +
21 +               if (c->flags & (1 << 7))
22 +                       ret = 1;
23 +               else
24 +                       ret = jffs2_scan_eraseblock(c, jeb);
25 +
26                 if (ret < 0)
27                         return ret;
28  
29 @@ -145,15 +154,22 @@
30                         c->nr_erasing_blocks++;
31                 }
32         }
33 -       /* Rotate the lists by some number to ensure wear levelling */
34 -       jffs2_rotate_lists(c);
35  
36 -       if (c->nr_erasing_blocks) {
37 -               if (!c->used_size && empty_blocks != c->nr_blocks) {
38 -                       printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
39 -                       return -EIO;
40 +       if (c->flags & (1 << 7)) {
41 +               printk("jffs2_scan_medium(): erasing all blocks after the end marker...\n");
42 +               jffs2_erase_pending_blocks(c);
43 +               printk("jffs2_scan_medium(): done.\n");
44 +       } else {
45 +               /* Rotate the lists by some number to ensure wear levelling */
46 +               jffs2_rotate_lists(c);
47 +
48 +               if (c->nr_erasing_blocks) {
49 +                       if (!c->used_size && empty_blocks != c->nr_blocks) {
50 +                               printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
51 +                               return -EIO;
52 +                       }
53 +                       jffs2_erase_pending_trigger(c);
54                 }
55 -               jffs2_erase_pending_trigger(c);
56         }
57         return 0;
58  }
59 @@ -181,6 +197,7 @@
60  
61         while(ofs < jeb->offset + c->sector_size) {
62                 ssize_t retlen;
63 +               unsigned char *buf = (unsigned char *) &node;
64                 ACCT_PARANOIA_CHECK(jeb);
65                 
66                 if (ofs & 3) {
67 @@ -202,8 +219,18 @@
68                         break;
69                 }
70  
71 -               err = c->mtd->read(c->mtd, ofs, sizeof(node), &retlen, (char *)&node);
72 +               err = c->mtd->read(c->mtd, ofs, sizeof(node), &retlen, buf);
73 +               if ((buf[0] == 0xde) &&
74 +                       (buf[1] == 0xad) &&
75 +                       (buf[2] == 0xc0) &&
76 +                       (buf[3] == 0xde)) {
77 +                               
78 +                       /* end of filesystem. erase everything after this point */
79 +                       c->flags |= (1 << 7);
80 +                       printk("jffs2_scan_eraseblock(): End of filesystem marker found at 0x%x\n", jeb->offset);
81                 
82 +                       return 1;
83 +               }
84                 if (err) {
85                         D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", sizeof(node), ofs, err));
86                         return err;
87