On Mon, Jul 30, 2012 at 03:14:28PM +0800, majianpeng wrote: > When exec bio_alloc, the bi_rw is zero.But after calling bio_add_page, What about submit_bio? That sets the bi_rw as well? > it will use bi_rw. > Fox example, in functiion __bio_add_page,it will call merge_bvec_fn(). function. > 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 */ So what does that mean? Without this patch what happens? > > > Jianpeng Ma (8): Can you collapse all of this in just one patch? > Evalue bio->bi_rw after calling bio_alloc() and before calling It is 'evaluate' > 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 + I am not really sure if that is correct. Does 'submit_bio' not do the job properly? > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
