On Wed, Apr 05, 2017 at 02:05:50PM +1000, Neil Brown wrote: > This is part of my little project to make bio splitting > in Linux uniform and dead-lock free, in a way that will mean > that we can get rid of all the bioset threads. > > The basic approach is that when a bio needs to be split, we call > bio_split(), bio_chain() and then generic_make_request(). > We then proceed to handle the remainder without further splitting. > Recent changes to generic_make_request() ensure that this will > be safe from deadlocks, providing each bioset is used only once > in the stack. > > This leads to simpler code in various places. In particular, the > splitting of bios that is needed to work around known bad blocks > is now much less complex. There is only ever one r1bio per bio. > > As you can see from > 10 files changed, 335 insertions(+), 540 deletions(-) > there is a net reduction in code. Looks good and makes code simpler, applied, thanks Neil! The patch 1 and 6 need comments in the code to explain how deadlock is avoided though. Care to send a new patch? Thanks, Shaohua > > Thanks, > NeilBrown > > --- > > NeilBrown (10): > md/raid1: simplify the splitting of requests. > md/raid1: simplify alloc_behind_master_bio() > Revert "block: introduce bio_copy_data_partial" > md/raid1: simplify handle_read_error(). > md/raid1: factor out flush_bio_list() > md/raid10: simplify the splitting of requests. > md/raid10: simplify handle_read_error() > md/raid5: make chunk_aligned_read() split bios more cleanly. > md/linear: improve bio splitting. > md/raid0: fix up bio splitting. > > > block/bio.c | 60 ++------- > drivers/md/linear.c | 75 +++++------ > drivers/md/raid0.c | 73 +++++------ > drivers/md/raid1.c | 346 ++++++++++++++++++++------------------------------- > drivers/md/raid1.h | 2 > drivers/md/raid10.c | 282 ++++++++++++++---------------------------- > drivers/md/raid10.h | 1 > drivers/md/raid5.c | 33 +++-- > drivers/md/raid5.h | 1 > include/linux/bio.h | 2 > 10 files changed, 335 insertions(+), 540 deletions(-) > > -- > Signature > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
