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[MTD] NAND Signal that a bitflip was corrected by ECC

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Return -EUCLEAN on read when a bitflip was detected and corrected, so the
clients can react and eventually copy the affected block to a spare one.
Make all in kernel users aware of the change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2006-05-29 14:56:39 +02:00
parent 8593fbc68b
commit 9a1fcdfd4b
6 changed files with 46 additions and 24 deletions
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7
drivers/mtd/inftlcore.c
View file

@ -355,7 +355,7 @@ static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned
ret = mtd->read(mtd, (inftl->EraseSize * BlockMap[block]) +
(block * SECTORSIZE), SECTORSIZE, &retlen,
movebuf);
if (ret < 0) {
if (ret < 0 && ret != -EUCLEAN) {
ret = mtd->read(mtd,
(inftl->EraseSize * BlockMap[block]) +
(block * SECTORSIZE), SECTORSIZE,
@ -922,7 +922,10 @@ foundit:
} else {
size_t retlen;
loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
if (mtd->read(mtd, ptr, SECTORSIZE, &retlen, buffer))
int ret = mtd->read(mtd, ptr, SECTORSIZE, &retlen, buffer);
/* Handle corrected bit flips gracefully */
if (ret < 0 && ret != -EUCLEAN)
return -EIO;
}
return 0;

5
drivers/mtd/mtdchar.c
View file

@ -199,10 +199,13 @@ static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t
/* Nand returns -EBADMSG on ecc errors, but it returns
* the data. For our userspace tools it is important
* to dump areas with ecc errors !
* For kernel internal usage it also might return -EUCLEAN
* to signal the caller that a bitflip has occured and has
* been corrected by the ECC algorithm.
* Userspace software which accesses NAND this way
* must be aware of the fact that it deals with NAND
*/
if (!ret || (ret == -EBADMSG)) {
if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
*ppos += retlen;
if (copy_to_user(buf, kbuf, retlen)) {
kfree(kbuf);

15
drivers/mtd/mtdconcat.c
View file

@ -56,7 +56,7 @@ concat_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t * retlen, u_char * buf)
{
struct mtd_concat *concat = CONCAT(mtd);
int err = -EINVAL;
int ret = 0, err = -EINVAL;
int i;
*retlen = 0;
@ -80,9 +80,18 @@ concat_read(struct mtd_info *mtd, loff_t from, size_t len,
err = subdev->read(subdev, from, size, &retsize, buf);
if (err)
if (err && (err != -EBADMSG) && (err != -EUCLEAN))
break;
/* Save information about bitflips! */
if (err) {
if (err == -EBADMSG)
ret = err;
else if (!ret)
ret = err;
err = 0;
}
*retlen += retsize;
len -= size;
if (len == 0)
@ -92,7 +101,7 @@ concat_read(struct mtd_info *mtd, loff_t from, size_t len,
buf += size;
from = 0;
}
return err;
return err ? err : ret;
}
static int

5
drivers/mtd/nand/nand_base.c
View file

@ -1035,7 +1035,10 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
if (ret)
return ret;
return mtd->ecc_stats.failed - stats.failed ? -EBADMSG : 0;
if (mtd->ecc_stats.failed - stats.failed)
return -EBADMSG;
return mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
}
/**

6
drivers/mtd/nftlcore.c
View file

@ -422,7 +422,7 @@ static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned p
ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512),
512, &retlen, movebuf);
if (ret < 0) {
if (ret < 0 && ret != -EUCLEAN) {
ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block])
+ (block * 512), 512, &retlen,
movebuf);
@ -768,7 +768,9 @@ static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
} else {
loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs;
size_t retlen;
if (mtd->read(mtd, ptr, 512, &retlen, buffer))
int res = mtd->read(mtd, ptr, 512, &retlen, buffer);
if (res < 0 && res != -EUCLEAN)
return -EIO;
}
return 0;

32
fs/jffs2/wbuf.c
View file

@ -296,10 +296,11 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
/* Do the read... */
ret = c->mtd->read(c->mtd, start, c->wbuf_ofs - start, &retlen, buf);
if (ret == -EBADMSG && retlen == c->wbuf_ofs - start) {
/* ECC recovered */
/* ECC recovered ? */
if ((ret == -EUCLEAN || ret == -EBADMSG) &&
(retlen == c->wbuf_ofs - start))
ret = 0;
}
if (ret || retlen != c->wbuf_ofs - start) {
printk(KERN_CRIT "Old data are already lost in wbuf recovery. Data loss ensues.\n");
@ -908,20 +909,21 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re
down_read(&c->wbuf_sem);
ret = c->mtd->read(c->mtd, ofs, len, retlen, buf);
if ( (ret == -EBADMSG) && (*retlen == len) ) {
printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx) returned ECC error\n",
len, ofs);
if ( (ret == -EBADMSG || ret == -EUCLEAN) && (*retlen == len) ) {
if (ret == -EBADMSG)
printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx)"
" returned ECC error\n", len, ofs);
/*
* We have the raw data without ECC correction in the buffer, maybe
* we are lucky and all data or parts are correct. We check the node.
* If data are corrupted node check will sort it out.
* We keep this block, it will fail on write or erase and the we
* mark it bad. Or should we do that now? But we should give him a chance.
* Maybe we had a system crash or power loss before the ecc write or
* a erase was completed.
* We have the raw data without ECC correction in the buffer,
* maybe we are lucky and all data or parts are correct. We
* check the node. If data are corrupted node check will sort
* it out. We keep this block, it will fail on write or erase
* and the we mark it bad. Or should we do that now? But we
* should give him a chance. Maybe we had a system crash or
* power loss before the ecc write or a erase was completed.
* So we return success. :)
*/
ret = 0;
ret = 0;
}
/* if no writebuffer available or write buffer empty, return */
@ -943,7 +945,7 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re
orbf = (c->wbuf_ofs - ofs); /* offset in read buffer */
if (orbf > len) /* is write beyond write buffer ? */
goto exit;
lwbf = len - orbf; /* number of bytes to copy */
lwbf = len - orbf; /* number of bytes to copy */
if (lwbf > c->wbuf_len)
lwbf = c->wbuf_len;
}