bio-integrity: Fix bio_integrity_verify segment start bug
Nicholas Bellinger [Wed, 22 Jan 2014 04:32:05 +0000 (20:32 -0800)]
commit 5837c80e870bc3b12ac6a98cdc9ce7a9522a8fb6 upstream.

This patch addresses a bug in bio_integrity_verify() code that has
been causing DIF READ verify operations to be silently skipped.

The issue is that bio->bi_idx will have been incremented within
bio_advance() code in the normal blk_update_request() ->
req_bio_endio() completion path, and bio_integrity_verify() is
using bio_for_each_segment() which starts the bio segment walk
at the current bio->bi_idx.

So instead use bio_for_each_segment_all() to always start the bio
segment walk from zero, regardless of the current bio->bi_idx
value after bio_advance() has been called.

(Context change for v3.10.y -> v3.13.y code - nab)

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/bio-integrity.c

index 8dccf73..433c3b8 100644 (file)
@@ -458,7 +458,7 @@ static int bio_integrity_verify(struct bio *bio)
        bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
        bix.sector_size = bi->sector_size;
 
-       bio_for_each_segment(bv, bio, i) {
+       bio_for_each_segment_all(bv, bio, i) {
                void *kaddr = kmap_atomic(bv->bv_page);
                bix.data_buf = kaddr + bv->bv_offset;
                bix.data_size = bv->bv_len;