[Ocfs2-devel] [PATCH 0/8] Set bi_rw when alloc bio before call bio_add_page.

majianpeng majianpeng at gmail.com
Mon Jul 30 00:13:24 PDT 2012


When exec bio_alloc, the bi_rw is zero.But after calling bio_add_page,
it will use bi_rw.
Fox example, in functiion __bio_add_page,it will call merge_bvec_fn().
The merge_bvec_fn of raid456 will use the bi_rw to judge the merge.
>> if ((bvm->bi_rw & 1) == WRITE)
>> return biovec->bv_len; /* always allow writes to be mergeable */


Jianpeng Ma (8):
  Evalue bio->bi_rw after calling bio_alloc() and before calling
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().
  Evalue bio->bi_rw after calling bio_alloc() and before calling    
    bio_add_page().

 block/blk-lib.c                     |    1 +
 drivers/block/xen-blkback/blkback.c |    1 +
 fs/btrfs/check-integrity.c          |    1 +
 fs/direct-io.c                      |    1 +
 fs/ext4/page-io.c                   |    1 +
 fs/jfs/jfs_metapage.c               |    1 +
 fs/ocfs2/cluster/heartbeat.c        |    8 +++++---
 fs/xfs/xfs_aops.c                   |    2 ++
 fs/xfs/xfs_buf.c                    |    1 +
 9 files changed, 14 insertions(+), 3 deletions(-)

-- 
1.7.9.5


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