block: Convert bio_for_each_segment() to bvec_iter

More prep work for immutable biovecs - with immutable bvecs drivers
won't be able to use the biovec directly, they'll need to use helpers
that take into account bio->bi_iter.bi_bvec_done.

This updates callers for the new usage without changing the
implementation yet.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jim Paris <jim@jtan.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: support@lsi.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: drbd-user@lists.linbit.com
Cc: nbd-general@lists.sourceforge.net
Cc: cbe-oss-dev@lists.ozlabs.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: DL-MPTFusionLinux@lsi.com
Cc: linux-scsi@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-fsdevel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mm@kvack.org
Acked-by: Geoff Levand <geoff@infradead.org>

1 files changed, 19 insertions, 14 deletions

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 53d217381873..5539d2920872 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -550,9 +550,11 @@ static int nvme_split_and_submit(struct bio *bio, struct nvme_queue *nvmeq,
 static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod,
                 struct bio *bio, enum dma_data_direction dma_dir, int psegs)
 {
-        struct bio_vec *bvec, *bvprv = NULL;
+        struct bio_vec bvec, bvprv;
+        struct bvec_iter iter;
         struct scatterlist *sg = NULL;
-        int i, length = 0, nsegs = 0, split_len = bio->bi_iter.bi_size;
+        int length = 0, nsegs = 0, split_len = bio->bi_iter.bi_size;
+        int first = 1;
 
         if (nvmeq->dev->stripe_size)
                 split_len = nvmeq->dev->stripe_size -
@@ -560,25 +562,28 @@ static int nvme_map_bio(struct nvme_queue *nvmeq, struct nvme_iod *iod,
                          (nvmeq->dev->stripe_size - 1));
 
         sg_init_table(iod->sg, psegs);
-        bio_for_each_segment(bvec, bio, i) {
-                if (bvprv && BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) {
-                        sg->length += bvec->bv_len;
+        bio_for_each_segment(bvec, bio, iter) {
+                if (!first && BIOVEC_PHYS_MERGEABLE(&bvprv, &bvec)) {
+                        sg->length += bvec.bv_len;
                 } else {
-                        if (bvprv && BIOVEC_NOT_VIRT_MERGEABLE(bvprv, bvec))
-                                return nvme_split_and_submit(bio, nvmeq, i,
-                                                                length, 0);
+                        if (!first && BIOVEC_NOT_VIRT_MERGEABLE(&bvprv, &bvec))
+                                return nvme_split_and_submit(bio, nvmeq,
+                                                             iter.bi_idx,
+                                                             length, 0);
 
                         sg = sg ? sg + 1 : iod->sg;
-                        sg_set_page(sg, bvec->bv_page, bvec->bv_len,
-                                                        bvec->bv_offset);
+                        sg_set_page(sg, bvec.bv_page,
+                                    bvec.bv_len, bvec.bv_offset);
                         nsegs++;
                 }
 
-                if (split_len - length < bvec->bv_len)
-                        return nvme_split_and_submit(bio, nvmeq, i, split_len,
-                                                        split_len - length);
-                length += bvec->bv_len;
+                if (split_len - length < bvec.bv_len)
+                        return nvme_split_and_submit(bio, nvmeq, iter.bi_idx,
+                                                     split_len,
+                                                     split_len - length);
+                length += bvec.bv_len;
                 bvprv = bvec;
+                first = 0;
         }
         iod->nents = nsegs;
         sg_mark_end(sg);