linux-toradex.git/drivers/md/raid10.c, branch PD13.0.0alpha

md: Avoid waking up a thread after it has been freed.

2011-10-16T21:14:53+00:00

commit 01f96c0a9922cd9919baf9d16febdf7016177a12 upstream.

Two related problems:

1/ some error paths call "md_unregister_thread(mddev->thread)"
   without subsequently clearing ->thread.  A subsequent call
   to mddev_unlock will try to wake the thread, and crash.

2/ Most calls to md_wakeup_thread are protected against the thread
   disappeared either by:
      - holding the ->mutex
      - having an active request, so something else must be keeping
        the array active.
   However mddev_unlock calls md_wakeup_thread after dropping the
   mutex and without any certainty of an active request, so the
   ->thread could theoretically disappear.
   So we need a spinlock to provide some protections.

So change md_unregister_thread to take a pointer to the thread
pointer, and ensure that it always does the required locking, and
clears the pointer properly.

Reported-by: "Moshe Melnikov" 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md/raid10: reformat some loops with less indenting.

2011-05-11T04:54:41+00:00

When a loop ends with an 'if' with a large body, it is neater
to make the if 'continue' on the inverse condition, and then
the body is indented less.

Apply this pattern 3 times, and wrap some other long lines.

Signed-off-by: NeilBrown

md/raid10: remove unused variable.

2011-05-11T04:54:32+00:00

This variable 'disk' is never used - how odd.

Signed-off-by: NeilBrown

md/raid10: make more use of 'slot' in raid10d.

2011-05-11T04:54:19+00:00

Now that we have a 'slot' variable, make better use of it to simplify
some code a little.

Signed-off-by: NeilBrown

md/raid10: some tidying up in fix_read_error

2011-05-11T04:53:17+00:00

Currently the rdev on which a read error happened could be removed
before we perform the fix_error handling.  This requires extra tests
for NULL.

So delay the rdev_dec_pending call until after the call to
fix_read_error so that we can be sure that the rdev still exists.

This allows an 'if' clause to be removed so the body gets re-indented
back one level.

Signed-off-by: NeilBrown

md: simplify raid10 read_balance

2011-05-11T04:27:03+00:00

raid10 read balance has two different loop for looking through
possible devices to chose the best.
Collapse those into one loop and generally make the code more
readable.

Signed-off-by: NeilBrown

md: fix up raid1/raid10 unplugging.

2011-04-18T08:25:43+00:00

We just need to make sure that an unplug event wakes up the md
thread, which is exactly what mddev_check_plugged does.

Also remove some plug-related code that is no longer needed.

Signed-off-by: NeilBrown

md: use new plugging interface for RAID IO.

2011-04-18T08:25:41+00:00

md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.

Signed-off-by: NeilBrown

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

block: Require subsystems to explicitly allocate bio_set integrity mempool

2011-03-17T10:11:05+00:00

MD and DM create a new bio_set for every metadevice. Each bio_set has an
integrity mempool attached regardless of whether the metadevice is
capable of passing integrity metadata. This is a waste of memory.

Instead we defer the allocation decision to MD and DM since we know at
metadevice creation time whether integrity passthrough is needed or not.

Automatic integrity mempool allocation can then be removed from
bioset_create() and we make an explicit integrity allocation for the
fs_bio_set.

Signed-off-by: Martin K. Petersen 
Reported-by: Zdenek Kabelac 
Acked-by: Mike Snitzer 
Signed-off-by: Jens Axboe