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>
diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 92bd22c..9cbc567 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -504,7 +504,7 @@
 	struct dasd_diag_req *dreq;
 	struct dasd_diag_bio *dbio;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst;
 	unsigned int count, datasize;
 	sector_t recid, first_rec, last_rec;
@@ -525,10 +525,10 @@
 	/* Check struct bio and count the number of blocks for the request. */
 	count = 0;
 	rq_for_each_segment(bv, req, iter) {
-		if (bv->bv_len & (blksize - 1))
+		if (bv.bv_len & (blksize - 1))
 			/* Fba can only do full blocks. */
 			return ERR_PTR(-EINVAL);
-		count += bv->bv_len >> (block->s2b_shift + 9);
+		count += bv.bv_len >> (block->s2b_shift + 9);
 	}
 	/* Paranoia. */
 	if (count != last_rec - first_rec + 1)
@@ -545,8 +545,8 @@
 	dbio = dreq->bio;
 	recid = first_rec;
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
-		for (off = 0; off < bv->bv_len; off += blksize) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
 			memset(dbio, 0, sizeof (struct dasd_diag_bio));
 			dbio->type = rw_cmd;
 			dbio->block_number = recid + 1;
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index cee7e27..70d1770 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2551,7 +2551,7 @@
 	struct dasd_ccw_req *cqr;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst;
 	unsigned int off;
 	int count, cidaw, cplength, datasize;
@@ -2573,13 +2573,13 @@
 	count = 0;
 	cidaw = 0;
 	rq_for_each_segment(bv, req, iter) {
-		if (bv->bv_len & (blksize - 1))
+		if (bv.bv_len & (blksize - 1))
 			/* Eckd can only do full blocks. */
 			return ERR_PTR(-EINVAL);
-		count += bv->bv_len >> (block->s2b_shift + 9);
+		count += bv.bv_len >> (block->s2b_shift + 9);
 #if defined(CONFIG_64BIT)
-		if (idal_is_needed (page_address(bv->bv_page), bv->bv_len))
-			cidaw += bv->bv_len >> (block->s2b_shift + 9);
+		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
+			cidaw += bv.bv_len >> (block->s2b_shift + 9);
 #endif
 	}
 	/* Paranoia. */
@@ -2650,16 +2650,16 @@
 			      last_rec - recid + 1, cmd, basedev, blksize);
 	}
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
+		dst = page_address(bv.bv_page) + bv.bv_offset;
 		if (dasd_page_cache) {
 			char *copy = kmem_cache_alloc(dasd_page_cache,
 						      GFP_DMA | __GFP_NOWARN);
 			if (copy && rq_data_dir(req) == WRITE)
-				memcpy(copy + bv->bv_offset, dst, bv->bv_len);
+				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
 			if (copy)
-				dst = copy + bv->bv_offset;
+				dst = copy + bv.bv_offset;
 		}
-		for (off = 0; off < bv->bv_len; off += blksize) {
+		for (off = 0; off < bv.bv_len; off += blksize) {
 			sector_t trkid = recid;
 			unsigned int recoffs = sector_div(trkid, blk_per_trk);
 			rcmd = cmd;
@@ -2735,7 +2735,7 @@
 	struct dasd_ccw_req *cqr;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst, *idaw_dst;
 	unsigned int cidaw, cplength, datasize;
 	unsigned int tlf;
@@ -2813,8 +2813,8 @@
 	idaw_dst = NULL;
 	idaw_len = 0;
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
-		seg_len = bv->bv_len;
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		seg_len = bv.bv_len;
 		while (seg_len) {
 			if (new_track) {
 				trkid = recid;
@@ -3039,7 +3039,7 @@
 {
 	struct dasd_ccw_req *cqr;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst;
 	unsigned int trkcount, ctidaw;
 	unsigned char cmd;
@@ -3125,8 +3125,8 @@
 		new_track = 1;
 		recid = first_rec;
 		rq_for_each_segment(bv, req, iter) {
-			dst = page_address(bv->bv_page) + bv->bv_offset;
-			seg_len = bv->bv_len;
+			dst = page_address(bv.bv_page) + bv.bv_offset;
+			seg_len = bv.bv_len;
 			while (seg_len) {
 				if (new_track) {
 					trkid = recid;
@@ -3158,9 +3158,9 @@
 		}
 	} else {
 		rq_for_each_segment(bv, req, iter) {
-			dst = page_address(bv->bv_page) + bv->bv_offset;
+			dst = page_address(bv.bv_page) + bv.bv_offset;
 			last_tidaw = itcw_add_tidaw(itcw, 0x00,
-						    dst, bv->bv_len);
+						    dst, bv.bv_len);
 			if (IS_ERR(last_tidaw)) {
 				ret = -EINVAL;
 				goto out_error;
@@ -3276,7 +3276,7 @@
 	struct dasd_ccw_req *cqr;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst;
 	unsigned char cmd;
 	unsigned int trkcount;
@@ -3376,8 +3376,8 @@
 			idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
 	}
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
-		seg_len = bv->bv_len;
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		seg_len = bv.bv_len;
 		if (cmd == DASD_ECKD_CCW_READ_TRACK)
 			memset(dst, 0, seg_len);
 		if (!len_to_track_end) {
@@ -3422,7 +3422,7 @@
 	struct dasd_eckd_private *private;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst, *cda;
 	unsigned int blksize, blk_per_trk, off;
 	sector_t recid;
@@ -3440,8 +3440,8 @@
 	if (private->uses_cdl == 0 || recid > 2*blk_per_trk)
 		ccw++;
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
-		for (off = 0; off < bv->bv_len; off += blksize) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
 			/* Skip locate record. */
 			if (private->uses_cdl && recid <= 2*blk_per_trk)
 				ccw++;
@@ -3452,7 +3452,7 @@
 					cda = (char *)((addr_t) ccw->cda);
 				if (dst != cda) {
 					if (rq_data_dir(req) == READ)
-						memcpy(dst, cda, bv->bv_len);
+						memcpy(dst, cda, bv.bv_len);
 					kmem_cache_free(dasd_page_cache,
 					    (void *)((addr_t)cda & PAGE_MASK));
 				}
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index 9cbc8c3..2c8e68b 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -260,7 +260,7 @@
 	struct dasd_ccw_req *cqr;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst;
 	int count, cidaw, cplength, datasize;
 	sector_t recid, first_rec, last_rec;
@@ -283,13 +283,13 @@
 	count = 0;
 	cidaw = 0;
 	rq_for_each_segment(bv, req, iter) {
-		if (bv->bv_len & (blksize - 1))
+		if (bv.bv_len & (blksize - 1))
 			/* Fba can only do full blocks. */
 			return ERR_PTR(-EINVAL);
-		count += bv->bv_len >> (block->s2b_shift + 9);
+		count += bv.bv_len >> (block->s2b_shift + 9);
 #if defined(CONFIG_64BIT)
-		if (idal_is_needed (page_address(bv->bv_page), bv->bv_len))
-			cidaw += bv->bv_len / blksize;
+		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
+			cidaw += bv.bv_len / blksize;
 #endif
 	}
 	/* Paranoia. */
@@ -326,16 +326,16 @@
 	}
 	recid = first_rec;
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
+		dst = page_address(bv.bv_page) + bv.bv_offset;
 		if (dasd_page_cache) {
 			char *copy = kmem_cache_alloc(dasd_page_cache,
 						      GFP_DMA | __GFP_NOWARN);
 			if (copy && rq_data_dir(req) == WRITE)
-				memcpy(copy + bv->bv_offset, dst, bv->bv_len);
+				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
 			if (copy)
-				dst = copy + bv->bv_offset;
+				dst = copy + bv.bv_offset;
 		}
-		for (off = 0; off < bv->bv_len; off += blksize) {
+		for (off = 0; off < bv.bv_len; off += blksize) {
 			/* Locate record for stupid devices. */
 			if (private->rdc_data.mode.bits.data_chain == 0) {
 				ccw[-1].flags |= CCW_FLAG_CC;
@@ -384,7 +384,7 @@
 	struct dasd_fba_private *private;
 	struct ccw1 *ccw;
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	char *dst, *cda;
 	unsigned int blksize, off;
 	int status;
@@ -399,8 +399,8 @@
 	if (private->rdc_data.mode.bits.data_chain != 0)
 		ccw++;
 	rq_for_each_segment(bv, req, iter) {
-		dst = page_address(bv->bv_page) + bv->bv_offset;
-		for (off = 0; off < bv->bv_len; off += blksize) {
+		dst = page_address(bv.bv_page) + bv.bv_offset;
+		for (off = 0; off < bv.bv_len; off += blksize) {
 			/* Skip locate record. */
 			if (private->rdc_data.mode.bits.data_chain == 0)
 				ccw++;
@@ -411,7 +411,7 @@
 					cda = (char *)((addr_t) ccw->cda);
 				if (dst != cda) {
 					if (rq_data_dir(req) == READ)
-						memcpy(dst, cda, bv->bv_len);
+						memcpy(dst, cda, bv.bv_len);
 					kmem_cache_free(dasd_page_cache,
 					    (void *)((addr_t)cda & PAGE_MASK));
 				}
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 16814a8..ebf41e2 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -808,12 +808,12 @@
 dcssblk_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct dcssblk_dev_info *dev_info;
-	struct bio_vec *bvec;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
 	unsigned long index;
 	unsigned long page_addr;
 	unsigned long source_addr;
 	unsigned long bytes_done;
-	int i;
 
 	bytes_done = 0;
 	dev_info = bio->bi_bdev->bd_disk->private_data;
@@ -844,21 +844,21 @@
 	}
 
 	index = (bio->bi_iter.bi_sector >> 3);
-	bio_for_each_segment(bvec, bio, i) {
+	bio_for_each_segment(bvec, bio, iter) {
 		page_addr = (unsigned long)
-			page_address(bvec->bv_page) + bvec->bv_offset;
+			page_address(bvec.bv_page) + bvec.bv_offset;
 		source_addr = dev_info->start + (index<<12) + bytes_done;
-		if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0)
+		if (unlikely((page_addr & 4095) != 0) || (bvec.bv_len & 4095) != 0)
 			// More paranoia.
 			goto fail;
 		if (bio_data_dir(bio) == READ) {
 			memcpy((void*)page_addr, (void*)source_addr,
-				bvec->bv_len);
+				bvec.bv_len);
 		} else {
 			memcpy((void*)source_addr, (void*)page_addr,
-				bvec->bv_len);
+				bvec.bv_len);
 		}
-		bytes_done += bvec->bv_len;
+		bytes_done += bvec.bv_len;
 	}
 	bio_endio(bio, 0);
 	return;
diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index d0ab501..76bed17 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -130,7 +130,7 @@
 	struct aidaw *aidaw = scmrq->aidaw;
 	struct msb *msb = &scmrq->aob->msb[0];
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 
 	msb->bs = MSB_BS_4K;
 	scmrq->aob->request.msb_count = 1;
@@ -142,9 +142,9 @@
 	msb->data_addr = (u64) aidaw;
 
 	rq_for_each_segment(bv, scmrq->request, iter) {
-		WARN_ON(bv->bv_offset);
-		msb->blk_count += bv->bv_len >> 12;
-		aidaw->data_addr = (u64) page_address(bv->bv_page);
+		WARN_ON(bv.bv_offset);
+		msb->blk_count += bv.bv_len >> 12;
+		aidaw->data_addr = (u64) page_address(bv.bv_page);
 		aidaw++;
 	}
 }
diff --git a/drivers/s390/block/scm_blk_cluster.c b/drivers/s390/block/scm_blk_cluster.c
index 27f930c..9aae909 100644
--- a/drivers/s390/block/scm_blk_cluster.c
+++ b/drivers/s390/block/scm_blk_cluster.c
@@ -122,7 +122,7 @@
 	struct aidaw *aidaw = scmrq->aidaw;
 	struct msb *msb = &scmrq->aob->msb[0];
 	struct req_iterator iter;
-	struct bio_vec *bv;
+	struct bio_vec bv;
 	int i = 0;
 	u64 addr;
 
@@ -163,7 +163,7 @@
 			i++;
 		}
 		rq_for_each_segment(bv, req, iter) {
-			aidaw->data_addr = (u64) page_address(bv->bv_page);
+			aidaw->data_addr = (u64) page_address(bv.bv_page);
 			aidaw++;
 			i++;
 		}
diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
index dd4e73f..3e530f9 100644
--- a/drivers/s390/block/xpram.c
+++ b/drivers/s390/block/xpram.c
@@ -184,11 +184,11 @@
 static void xpram_make_request(struct request_queue *q, struct bio *bio)
 {
 	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
-	struct bio_vec *bvec;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
 	unsigned int index;
 	unsigned long page_addr;
 	unsigned long bytes;
-	int i;
 
 	if ((bio->bi_iter.bi_sector & 7) != 0 ||
 	    (bio->bi_iter.bi_size & 4095) != 0)
@@ -200,10 +200,10 @@
 	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
 		goto fail;
 	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
-	bio_for_each_segment(bvec, bio, i) {
+	bio_for_each_segment(bvec, bio, iter) {
 		page_addr = (unsigned long)
-			kmap(bvec->bv_page) + bvec->bv_offset;
-		bytes = bvec->bv_len;
+			kmap(bvec.bv_page) + bvec.bv_offset;
+		bytes = bvec.bv_len;
 		if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
 			/* More paranoia. */
 			goto fail;