[PATCH] sg traverse fix for __atapi_pio_bytes()
Problem:
Incorrect md5sum when using ATAPI PIO mode to verify a distro CD.
Root cause: sg traverse problem.
In __atapi_pio_bytes(), if qc->cursg++ is increased and "goto
next_page" is executed, then sg is not updated to the new qc->cursg
and the old sg is overwritten with the new data.
Changes:
- Replace "goto next_page" with "goto next_sg" to make sg updated.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 21d194c..9e58f13 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2577,7 +2577,6 @@
next_sg:
sg = &qc->sg[qc->cursg];
-next_page:
page = sg->page;
offset = sg->offset + qc->cursg_ofs;
@@ -2585,6 +2584,7 @@
page = nth_page(page, (offset >> PAGE_SHIFT));
offset %= PAGE_SIZE;
+ /* don't overrun current sg */
count = min(sg->length - qc->cursg_ofs, bytes);
/* don't cross page boundaries */
@@ -2609,8 +2609,6 @@
kunmap(page);
if (bytes) {
- if (qc->cursg_ofs < sg->length)
- goto next_page;
goto next_sg;
}
}