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, 6 insertions, 9 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f1a77449d032..d6630dc130ba 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6779,17 +6779,16 @@ unlock_err:
 static void btrfs_endio_direct_read(struct bio *bio, int err)
 {
         struct btrfs_dio_private *dip = bio->bi_private;
-        struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
-        struct bio_vec *bvec = bio->bi_io_vec;
+        struct bio_vec *bvec;
         struct inode *inode = dip->inode;
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct bio *dio_bio;
         u32 *csums = (u32 *)dip->csum;
-        int index = 0;
         u64 start;
+        int i;
 
         start = dip->logical_offset;
-        do {
+        bio_for_each_segment_all(bvec, bio, i) {
                 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
                         struct page *page = bvec->bv_page;
                         char *kaddr;
@@ -6805,18 +6804,16 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
                         local_irq_restore(flags);
 
                         flush_dcache_page(bvec->bv_page);
-                        if (csum != csums[index]) {
+                        if (csum != csums[i]) {
                                 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
                                           btrfs_ino(inode), start, csum,
-                                          csums[index]);
+                                          csums[i]);
                                 err = -EIO;
                         }
                 }
 
                 start += bvec->bv_len;
-                bvec++;
-                index++;
-        } while (bvec <= bvec_end);
+        }
 
         unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
                       dip->logical_offset + dip->bytes - 1);