linux-toradex.git/drivers/md/raid10.h, branch v3.2.46

md: add proper write-congestion reporting to RAID1 and RAID10.

2011-10-11T05:50:01+00:00

RAID1 and RAID10 handle write requests by queuing them for handling by
a separate thread.  This is because when a write-intent-bitmap is
active we might need to update the bitmap first, so it is good to
queue a lot of writes, then do one big bitmap update for them all.

However writeback request devices to appear to be congested after a
while so it can make some guesstimate of throughput.  The infinite
queue defeats that (note that RAID5 has already has a finite queue so
it doesn't suffer from this problem).

So impose a limit on the number of pending write requests.  By default
it is 1024 which seems to be generally suitable.  Make it configurable
via module option just in case someone finds a regression.

Signed-off-by: NeilBrown

md/raid10: typedef removal: conf_t -> struct r10conf

2011-10-11T05:49:02+00:00

Signed-off-by: NeilBrown

md: remove typedefs: mirror_info_t -> struct mirror_info

2011-10-11T05:48:46+00:00

Signed-off-by: NeilBrown

md: remove typedefs: r10bio_t -> struct r10bio and r1bio_t -> struct r1bio

2011-10-11T05:48:43+00:00

Signed-off-by: NeilBrown

md: remove typedefs: mdk_thread_t -> struct md_thread

2011-10-11T05:48:23+00:00

Signed-off-by: NeilBrown

md: remove typedefs: mddev_t -> struct mddev

2011-10-11T05:47:53+00:00

Having mddev_t and 'struct mddev_s' is ugly and not preferred

Signed-off-by: NeilBrown

md: removing typedefs: mdk_rdev_t -> struct md_rdev

2011-10-11T05:45:26+00:00

The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown

md/raid10: Handle write errors by updating badblock log.

2011-07-28T01:39:24+00:00

When we get a write error (in the data area, not in metadata),
update the badblock log rather than failing the whole device.

As the write may well be many blocks, we trying writing each
block individually and only log the ones which fail.

Signed-off-by: NeilBrown

md/raid10: clear bad-block record when write succeeds.

2011-07-28T01:39:24+00:00

If we succeed in writing to a block that was recorded as
being bad, we clear the bad-block record.

This requires some delayed handling as the bad-block-list update has
to happen in process-context.

Signed-off-by: NeilBrown

md/raid10: avoid reading from known bad blocks - part 1

2011-07-28T01:39:23+00:00

This patch just covers the basic read path:
 1/ read_balance needs to check for badblocks, and return not only
    the chosen slot, but also how many good blocks are available
    there.
 2/ read submission must be ready to issue multiple reads to
    different devices as different bad blocks on different devices
    could mean that a single large read cannot be served by any one
    device, but can still be served by the array.
    This requires keeping count of the number of outstanding requests
    per bio.  This count is stored in 'bi_phys_segments'

On read error we currently just fail the request if another target
cannot handle the whole request.  Next patch refines that a bit.

Signed-off-by: NeilBrown