block: Convert bio_iovec() to bvec_iter

For immutable biovecs, we'll be introducing a new bio_iovec() that uses
our new bvec iterator to construct a biovec, taking into account
bvec_iter->bi_bvec_done - this patch updates existing users for the new
usage.

Some of the existing users really do need a pointer into the bvec array
- those uses are all going to be removed, but we'll need the
functionality from immutable to remove them - so for now rename the
existing bio_iovec() -> __bio_iovec(), and it'll be removed in a couple
patches.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>

4 files changed, 10 insertions, 9 deletions

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 877ba119b3f8..77c24ab1898a 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -932,7 +932,7 @@ bufinit(struct buf *buf, struct request *rq, struct bio *bio)
         buf->resid = bio->bi_iter.bi_size;
         buf->sector = bio->bi_iter.bi_sector;
         bio_pageinc(bio);
-        buf->bv = bio_iovec(bio);
+        buf->bv = __bio_iovec(bio);
         buf->bv_resid = buf->bv->bv_len;
         WARN_ON(buf->bv_resid == 0);
 }
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c
index cc4ba2da5fb6..dc44f0689eb7 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -22,11 +22,12 @@ static void bch_bi_idx_hack_endio(struct bio *bio, int error)
 static void bch_generic_make_request_hack(struct bio *bio)
 {
         if (bio->bi_iter.bi_idx) {
+                int i;
+                struct bio_vec *bv;
                 struct bio *clone = bio_alloc(GFP_NOIO, bio_segments(bio));
 
-                memcpy(clone->bi_io_vec,
-                       bio_iovec(bio),
-                       bio_segments(bio) * sizeof(struct bio_vec));
+                bio_for_each_segment(bv, bio, i)
+                        clone->bi_io_vec[clone->bi_vcnt++] = *bv;
 
                 clone->bi_iter.bi_sector = bio->bi_iter.bi_sector;
                 clone->bi_bdev          = bio->bi_bdev;
@@ -97,7 +98,7 @@ struct bio *bch_bio_split(struct bio *bio, int sectors,
                         if (!ret)
                                 return NULL;
 
-                        memcpy(ret->bi_io_vec, bio_iovec(bio),
+                        memcpy(ret->bi_io_vec, __bio_iovec(bio),
                                sizeof(struct bio_vec) * vcnt);
 
                         break;
@@ -106,7 +107,7 @@ struct bio *bch_bio_split(struct bio *bio, int sectors,
                         if (!ret)
                                 return NULL;
 
-                        memcpy(ret->bi_io_vec, bio_iovec(bio),
+                        memcpy(ret->bi_io_vec, __bio_iovec(bio),
                                sizeof(struct bio_vec) * vcnt);
 
                         ret->bi_io_vec[vcnt - 1].bv_len = nbytes;
@@ -182,7 +183,7 @@ static unsigned bch_bio_max_sectors(struct bio *bio)
         ret = min(ret, queue_max_sectors(q));
 
         WARN_ON(!ret);
-        ret = max_t(int, ret, bio_iovec(bio)->bv_len >> 9);
+        ret = max_t(int, ret, bio_iovec(bio).bv_len >> 9);
 
         return ret;
 }
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 132b3154d466..5392135924ca 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -524,7 +524,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio)
                 io->io_vec = io->io_vec_inline;
         else
                 io->io_vec = mempool_alloc(v->vec_mempool, GFP_NOIO);
-        memcpy(io->io_vec, bio_iovec(bio),
+        memcpy(io->io_vec, __bio_iovec(bio),
                io->io_vec_size * sizeof(struct bio_vec));
 
         verity_submit_prefetch(v, io);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e6c4bff04339..200d6bc81240 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -801,7 +801,7 @@ static int sd_setup_write_same_cmnd(struct scsi_device *sdp, struct request *rq)
         if (sdkp->device->no_write_same)
                 return BLKPREP_KILL;
 
-        BUG_ON(bio_offset(bio) || bio_iovec(bio)->bv_len != sdp->sector_size);
+        BUG_ON(bio_offset(bio) || bio_iovec(bio).bv_len != sdp->sector_size);
 
         sector >>= ilog2(sdp->sector_size) - 9;
         nr_sectors >>= ilog2(sdp->sector_size) - 9;