block: Abstract out bvec iterator

Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

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: Matthew Wilcox <willy@linux.intel.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: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchand@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peng Tao <tao.peng@emc.com>
Cc: Andy Adamson <andros@netapp.com>
Cc: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Pankaj Kumar <pankaj.km@samsung.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>6

1 files changed, 29 insertions, 27 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 33d79a4eb92..a402ad6e753 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -532,13 +532,13 @@ void __bio_clone(struct bio *bio, struct bio *bio_src)
 	 * most users will be overriding ->bi_bdev with a new target,
 	 * so we don't set nor calculate new physical/hw segment counts here
 	 */
-	bio->bi_sector = bio_src->bi_sector;
+	bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
 	bio->bi_bdev = bio_src->bi_bdev;
 	bio->bi_flags |= 1 << BIO_CLONED;
 	bio->bi_rw = bio_src->bi_rw;
 	bio->bi_vcnt = bio_src->bi_vcnt;
-	bio->bi_size = bio_src->bi_size;
-	bio->bi_idx = bio_src->bi_idx;
+	bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
+	bio->bi_iter.bi_idx = bio_src->bi_iter.bi_idx;
 }
 EXPORT_SYMBOL(__bio_clone);
 
@@ -612,7 +612,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	if (unlikely(bio_flagged(bio, BIO_CLONED)))
 		return 0;
 
-	if (((bio->bi_size + len) >> 9) > max_sectors)
+	if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
 		return 0;
 
 	/*
@@ -635,8 +635,9 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 					   simulate merging updated prev_bvec
 					   as new bvec. */
 					.bi_bdev = bio->bi_bdev,
-					.bi_sector = bio->bi_sector,
-					.bi_size = bio->bi_size - prev_bv_len,
+					.bi_sector = bio->bi_iter.bi_sector,
+					.bi_size = bio->bi_iter.bi_size -
+						prev_bv_len,
 					.bi_rw = bio->bi_rw,
 				};
 
@@ -684,8 +685,8 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	if (q->merge_bvec_fn) {
 		struct bvec_merge_data bvm = {
 			.bi_bdev = bio->bi_bdev,
-			.bi_sector = bio->bi_sector,
-			.bi_size = bio->bi_size,
+			.bi_sector = bio->bi_iter.bi_sector,
+			.bi_size = bio->bi_iter.bi_size,
 			.bi_rw = bio->bi_rw,
 		};
 
@@ -708,7 +709,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	bio->bi_vcnt++;
 	bio->bi_phys_segments++;
  done:
-	bio->bi_size += len;
+	bio->bi_iter.bi_size += len;
 	return len;
 }
 
@@ -807,22 +808,22 @@ void bio_advance(struct bio *bio, unsigned bytes)
 	if (bio_integrity(bio))
 		bio_integrity_advance(bio, bytes);
 
-	bio->bi_sector += bytes >> 9;
-	bio->bi_size -= bytes;
+	bio->bi_iter.bi_sector += bytes >> 9;
+	bio->bi_iter.bi_size -= bytes;
 
 	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
 		return;
 
 	while (bytes) {
-		if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
+		if (unlikely(bio->bi_iter.bi_idx >= bio->bi_vcnt)) {
 			WARN_ONCE(1, "bio idx %d >= vcnt %d\n",
-				  bio->bi_idx, bio->bi_vcnt);
+				  bio->bi_iter.bi_idx, bio->bi_vcnt);
 			break;
 		}
 
 		if (bytes >= bio_iovec(bio)->bv_len) {
 			bytes -= bio_iovec(bio)->bv_len;
-			bio->bi_idx++;
+			bio->bi_iter.bi_idx++;
 		} else {
 			bio_iovec(bio)->bv_len -= bytes;
 			bio_iovec(bio)->bv_offset += bytes;
@@ -1485,7 +1486,7 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
 	if (IS_ERR(bio))
 		return bio;
 
-	if (bio->bi_size == len)
+	if (bio->bi_iter.bi_size == len)
 		return bio;
 
 	/*
@@ -1763,16 +1764,16 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
 		return bp;
 
 	trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
-				bi->bi_sector + first_sectors);
+				bi->bi_iter.bi_sector + first_sectors);
 
 	BUG_ON(bio_segments(bi) > 1);
 	atomic_set(&bp->cnt, 3);
 	bp->error = 0;
 	bp->bio1 = *bi;
 	bp->bio2 = *bi;
-	bp->bio2.bi_sector += first_sectors;
-	bp->bio2.bi_size -= first_sectors << 9;
-	bp->bio1.bi_size = first_sectors << 9;
+	bp->bio2.bi_iter.bi_sector += first_sectors;
+	bp->bio2.bi_iter.bi_size -= first_sectors << 9;
+	bp->bio1.bi_iter.bi_size = first_sectors << 9;
 
 	if (bi->bi_vcnt != 0) {
 		bp->bv1 = *bio_iovec(bi);
@@ -1821,21 +1822,22 @@ void bio_trim(struct bio *bio, int offset, int size)
 	int sofar = 0;
 
 	size <<= 9;
-	if (offset == 0 && size == bio->bi_size)
+	if (offset == 0 && size == bio->bi_iter.bi_size)
 		return;
 
 	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
 
 	bio_advance(bio, offset << 9);
 
-	bio->bi_size = size;
+	bio->bi_iter.bi_size = size;
 
 	/* avoid any complications with bi_idx being non-zero*/
-	if (bio->bi_idx) {
-		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
-			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
-		bio->bi_vcnt -= bio->bi_idx;
-		bio->bi_idx = 0;
+	if (bio->bi_iter.bi_idx) {
+		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_iter.bi_idx,
+			(bio->bi_vcnt - bio->bi_iter.bi_idx) *
+			sizeof(struct bio_vec));
+		bio->bi_vcnt -= bio->bi_iter.bi_idx;
+		bio->bi_iter.bi_idx = 0;
 	}
 	/* Make sure vcnt and last bv are not too big */
 	bio_for_each_segment(bvec, bio, i) {
@@ -1871,7 +1873,7 @@ sector_t bio_sector_offset(struct bio *bio, unsigned short index,
 	sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue);
 	sectors = 0;
 
-	if (index >= bio->bi_idx)
+	if (index >= bio->bi_iter.bi_idx)
 		index = bio->bi_vcnt - 1;
 
 	bio_for_each_segment_all(bv, bio, i) {