bio-integrity: Drop bio_integrity_verify BUG_ON in post bip->bip_iter world

Given that bip->bip_iter.bi_size is decremented after bio_advance() ->
bio_integrity_advance() is called, the BUG_ON() in bio_integrity_verify()
ends up tripping in v3.14-rc1 code with the advent of immutable biovecs
in:

commit d57a5f7c6605f15f3b5134837e68b448a7cea88e
Author: Kent Overstreet <kmo@daterainc.com>
Date:   Sat Nov 23 17:20:16 2013 -0800

    bio-integrity: Convert to bvec_iter

Given that there is no easy way to ascertain the original bi_size
value, go ahead and drop this BUG_ON().

Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reported-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index 0129b78a6908..4f70f383132c 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -458,11 +458,10 @@ static int bio_integrity_verify(struct bio *bio)
         struct blk_integrity_exchg bix;
         struct bio_vec *bv;
         sector_t sector = bio->bi_integrity->bip_iter.bi_sector;
-        unsigned int sectors, total, ret;
+        unsigned int sectors, ret = 0;
         void *prot_buf = bio->bi_integrity->bip_buf;
         int i;
 
-        ret = total = 0;
         bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
         bix.sector_size = bi->sector_size;
 
@@ -484,8 +483,6 @@ static int bio_integrity_verify(struct bio *bio)
                 sectors = bv->bv_len / bi->sector_size;
                 sector += sectors;
                 prot_buf += sectors * bi->tuple_size;
-                total += sectors * bi->tuple_size;
-                BUG_ON(total > bio->bi_integrity->bip_iter.bi_size);
 
                 kunmap_atomic(kaddr);
         }