JFFS2: don't fail on bitflips in OOB

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 6f4529d3697fd3f97d5b018dbe9f5c0362cee034..a6597d60d76de751224243ddfe6d990cd6de7e87 100644 (file)
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -1044,10 +1044,10 @@ int jffs2_check_oob_empty(struct jffs2_sb_info *c,
        ops.datbuf = NULL;
 
        ret = mtd_read_oob(c->mtd, jeb->offset, &ops);
-       if (ret || ops.oobretlen != ops.ooblen) {
+       if ((ret && !mtd_is_bitflip(ret)) || ops.oobretlen != ops.ooblen) {
                pr_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;
        }
@@ -1086,10 +1086,10 @@ int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c,
        ops.datbuf = NULL;
 
        ret = mtd_read_oob(c->mtd, jeb->offset, &ops);
-       if (ret || ops.oobretlen != ops.ooblen) {
+       if ((ret && !mtd_is_bitflip(ret)) || ops.oobretlen != ops.ooblen) {
                pr_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;
        }