[ 081/147] JFFS2: dont fail on bitflips in OOB

Ben Hutchings
2012-10-14T14:59:57Z

From: Brian Norris <computersforpeace@gmail.com>

commit 74d83beaa229aac7d126ac1ed9414658ff1a89d2 upstream.

JFFS2 was designed without thought for OOB bitflips, it seems, but they
can occur and will be reported to JFFS2 via mtd_read_oob()[1]. We don't
want to fail on these transactions, since the data was corrected.

[1] Few drivers report bitflips for OOB-only transactions. With such
drivers, this patch should have no effect.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/jffs2/wbuf.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -1032,11 +1032,11 @@ int jffs2_check_oob_empty(struct jffs2_s
ops.datbuf = NULL;

ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
- if (ret || ops.oobretlen != ops.ooblen) {
+ if ((ret && !mtd_is_bitflip(ret)) || ops.oobretlen != ops.ooblen) {
printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
" bytes, read %zd bytes, error %d\n",
jeb->offset, ops.ooblen, ops.oobretlen, ret);
- if (!ret)
+ if (!ret || mtd_is_bitflip(ret))
ret = -EIO;
return ret;
}
@@ -1075,11 +1075,11 @@ int jffs2_check_nand_cleanmarker(struct
ops.datbuf = NULL;

ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
- if (ret || ops.oobretlen != ops.ooblen) {
+ if ((ret && !mtd_is_bitflip(ret)) || ops.oobretlen != ops.ooblen) {
printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
" bytes, read %zd bytes, error %d\n",
jeb->offset, ops.ooblen, ops.oobretlen, ret);
- if (!ret)
+ if (!ret || mtd_is_bitflip(ret))
ret = -EIO;
return ret;
}