From 5496213aa34345eaeade5b5d662879ca553d7f76 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kmo@daterainc.com>
Date: Thu, 7 Nov 2013 12:20:26 -0800
Subject: fs/mpage.c: Convert to use bio_for_each_segment()

With immutable biovecs we don't want code accessing bi_io_vec directly -
the uses this patch changes weren't incorrect since they all own the
bio, but it makes the code harder to audit for no good reason - also,
this will help with multipage bvecs later.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>

Upstream 2c30c71bd653afcbed7f6754e8fe3d16e0e708a1.
Patch applied just to fs/mpage.c for future merges.

Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
---
 fs/mpage.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/fs/mpage.c b/fs/mpage.c
index 4e15e652e..6d6699a25 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -43,16 +43,14 @@
  */
 static void mpage_end_io(struct bio *bio, int err)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bv;
+	int i;
 
-	do {
-		struct page *page = bvec->bv_page;
+	bio_for_each_segment_all(bv, bio, i) {
+		struct page *page = bv->bv_page;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
 		if (bio_data_dir(bio) == READ) {
-			if (uptodate) {
+			if (!err) {
 				SetPageUptodate(page);
 			} else {
 				ClearPageUptodate(page);
@@ -60,14 +58,15 @@ static void mpage_end_io(struct bio *bio, int err)
 			}
 			unlock_page(page);
 		} else { /* bio_data_dir(bio) == WRITE */
-			if (!uptodate) {
+			if (err) {
 				SetPageError(page);
 				if (page->mapping)
 					set_bit(AS_EIO, &page->mapping->flags);
 			}
 			end_page_writeback(page);
 		}
-	} while (bvec >= bio->bi_io_vec);
+	}
+
 	bio_put(bio);
 }
 
-- 
cgit v1.2.3