linux-toradex.git/drivers/md/raid5.h, branch v3.4.2

md/raid5: detect and handle replacements during recovery.

2011-12-22T23:17:53+00:00

During recovery we want to write to the replacement but not
the original.  So we have two new flags
 - R5_NeedReplace if this stripe has a replacement that needs to
   be written at some stage
 - R5_WantReplace if NeedReplace, and the data is available, and
   a 'sync' has been requested on this stripe.

We also distinguish between 'sync and replace' which need to read
all other devices, and 'replace' which only needs to read the
devices being replaced.

Note that during resync we always write to any replacement device.
It might not need to be written to, but as we don't read to compare,
we have to write to be sure.

Signed-off-by: NeilBrown

md/raid5: writes should get directed to replacement as well as original.

2011-12-22T23:17:53+00:00

When writing, we need to submit two writes, one to the original, and
one to the replacement - if there is a replacement.

If the write to the replacement results in a write error, we just fail
the device.  We only try to record write errors to the original.

When writing for recovery, we shouldn't write to the original.  This
will be addressed in a subsequent patch that generally addresses
recovery.

Reviewed-by: Dan Williams 
Signed-off-by: NeilBrown

md/raid5: raid5.h cleanup

2011-12-22T23:17:52+00:00

Remove some #defines that are no longer used, and replace some
others with an enum.
And remove an unused field.

Reviewed-by: Dan Williams 
Signed-off-by: NeilBrown

md/raid5: allow each slot to have an extra replacement device

2011-12-22T23:17:52+00:00

Just enhance data structures to record a second device per slot to be
used as a 'replacement' device, replacing the original.
We also have a second bio in each slot in each stripe_head.  This will
only be used when writing to the array - we need to write to both the
original and the replacement at the same time, so will need two bios.

For now, only try using the replacement drive for aligned-reads.
In this case, we prefer the replacement if it has been recovered far
enough, otherwise use the original.

This includes a small enhancement.  Previously we would only do
aligned reads if the target device was fully recovered.  Now we also
do them if it has recovered far enough.

Reviewed-by: Dan Williams 
Signed-off-by: NeilBrown

md/raid5: typedef removal: raid5_conf_t -> struct r5conf

2011-10-11T05:49:52+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/raid5: Clear bad blocks on successful write.

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

On a successful write to a known bad block, flag the sh
so that raid5d can remove the known bad block from the list.

Signed-off-by: NeilBrown

md/raid5: write errors should be recorded as bad blocks if possible.

2011-07-28T01:39:22+00:00

When a write error is detected, don't mark the device as failed
immediately but rather record the fact for handle_stripe to deal with.

Handle_stripe then attempts to record a bad block.  Only if that fails
does the device get marked as faulty.

Signed-off-by: NeilBrown