Re: EBH with OneNAND doesn't work

Jarkko Lavinen
2005-12-21T09:31:06Z

Thanks Christian, your patch helpt me to get JFFS2 working without
using too many printks.

Currently wbuf.c:jffs2_check_nand_cleanmarker_ebh() assumes the node header
fits in the first free region. The magic and node type would take 4 bytes.
If we have only 2 byte free regions available, this is not enough
and the struct jffs2_unknown_node needs to be assembled.

I am using new helper function jffs2_copy_nand_fsdata(), from Forrest's code.
Forrest assembled the longer EBH struct (28 bytes) from several free
regions. Similar assmebly is also needed for the struct unknown_node.

Optimally JFFS2 would use more free regions available at OOB. This would
result fewer amount of OOBs being used less writing to OOBs.

Jarkko Lavinen

Index: fs/jffs2/wbuf.c
===================================================================
RCS file: /home/cvs/mtd/fs/jffs2/wbuf.c,v
retrieving revision 1.108
diff -u -b -B -p -r1.108 wbuf.c
--- fs/jffs2/wbuf.c 18 Nov 2005 07:27:45 -0000 1.108
+++ fs/jffs2/wbuf.c 21 Dec 2005 09:19:56 -0000
@@ -984,6 +984,21 @@ out:
return ret;
}

+static void jffs2_copy_nand_fsdata(struct jffs2_sb_info *c, void *to,
+ unsigned char *from, int len, int oob_size)
+{
+ uint32_t read_in, i, copy_len;
+
+ read_in = i = 0;
+ while (read_in < len) {
+ copy_len = min_t(uint32_t, c->fsdata_len, len - read_in);
+ memcpy(to + read_in, &from[oob_size*i + c->fsdata_pos], copy_len);
+ read_in += copy_len;
+ i++;
+ }
+
+}
+
/*
* Scan for a valid cleanmarker and for bad blocks
* For virtual blocks (concatenated physical blocks) check the cleanmarker
@@ -997,9 +1012,9 @@ int jffs2_check_nand_cleanmarker_ebh (st
uint32_t oob_nr, total_len;
unsigned char *buf;
int ret;
- struct jffs2_unknown_node *n;
+ struct jffs2_unknown_node *n, unode;
struct jffs2_raw_ebh eh;
- uint32_t read_in = 0, i = 0, copy_len, node_crc;
+ uint32_t node_crc;

offset = jeb->offset;
*data_len = 0;
@@ -1028,7 +1043,13 @@ int jffs2_check_nand_cleanmarker_ebh (st
goto out;
}

+ if (c->fsdata_len >= sizeof(struct jffs2_unknown_node *)) {
n = (struct jffs2_unknown_node *) &buf[c->fsdata_pos];
+ } else {
+ n = &unode;
+ jffs2_copy_nand_fsdata(c, n, buf, sizeof(sizeof(struct jffs2_unknown_node)), oob_size);
+ }
+
if (je16_to_cpu(n->magic) != JFFS2_MAGIC_BITMASK) {
D1 (printk(KERN_WARNING "jffs2_check_nand_cleanmarker_ebh(): Cleanmarker node not detected in block at %08x\n", jeb->offset));
ret = 1;
@@ -1043,16 +1064,11 @@ int jffs2_check_nand_cleanmarker_ebh (st
ret = 1;
}
goto out;
- }else if (je16_to_cpu(n->nodetype) == JFFS2_NODETYPE_ERASEBLOCK_HEADER) {
+ } else if (je16_to_cpu(n->nodetype) == JFFS2_NODETYPE_ERASEBLOCK_HEADER) {
/* Read the scattered data(in buf[]) into struct jffs2_raw_ebh */
- while (read_in < sizeof(struct jffs2_raw_ebh)) {
- copy_len = min_t(uint32_t, c->fsdata_len, sizeof(struct jffs2_raw_ebh) - read_in);
- memcpy((unsigned char *)&eh + read_in, &buf[oob_size*i + c->fsdata_pos], copy_len);
- read_in += copy_len;
- i++;
- }
+ jffs2_copy_nand_fsdata(c, &eh, buf, sizeof(struct jffs2_raw_ebh), oob_size);

- node_crc = crc32(0, &eh, sizeof(struct jffs2_raw_ebh)-8);
+ node_crc = crc32(0, &eh, sizeof(struct jffs2_raw_ebh) - 8);
if (node_crc != je32_to_cpu(eh.node_crc)) {
ret = 1;
goto out;