From 6952df035509717bdc46194b2a3d6ffb9349f267 Mon Sep 17 00:00:00 2001 From: Albert Lee Date: Mon, 6 Jun 2005 15:56:03 +0800 Subject: [PATCH] [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 --- drivers/scsi/libata-core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) 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 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes) next_sg: sg = &qc->sg[qc->cursg]; -next_page: page = sg->page; offset = sg->offset + qc->cursg_ofs; @@ -2585,6 +2584,7 @@ next_page: 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 @@ next_page: kunmap(page); if (bytes) { - if (qc->cursg_ofs < sg->length) - goto next_page; goto next_sg; } } -- 2.7.4