block: Convert various code to 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>

1 files changed, 8 insertions, 9 deletions

diff --git a/fs/mpage.c b/fs/mpage.c
index 0face1c4d4c6..dd6d5878f4d9 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);
 }