linux-stable.git/drivers/md/bitmap.h, branch linux-2.6.32.y

md/raid1: delay reads that could overtake behind-writes.

2010-08-13T20:20:25+00:00

commit e555190d82c0f58e825e3cbd9e6ebe2e7ac713bd upstream.

When a raid1 array is configured to support write-behind
on some devices, it normally only reads from other devices.
If all devices are write-behind (because the rest have failed)
it is possible for a read request to be serviced before a
behind-write request, which would appear as data corruption.

So when forced to read from a WriteMostly device, wait for any
write-behind to complete, and don't start any more behind-writes.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md/bitmap: protect against bitmap removal while being updated.

2009-12-18T22:04:11+00:00

commit aa5cbd103887011b4830355f88fb055f9ad2d556 upstream.

A write intent bitmap can be removed from an array while the
array is active.
When this happens, all IO is suspended and flushed before the
bitmap is removed.
However it is possible that bitmap_daemon_work is still running to
clear old bits from the bitmap.  If it is, it can dereference the
bitmap after it has been freed.

So introduce a new mutex to protect bitmap_daemon_work and get it
before destroying a bitmap.

This is suitable for any current -stable kernel.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: move headers out of include/linux/raid/

2009-03-31T03:27:03+00:00

Move the headers with the local structures for the disciplines and
bitmap.h into drivers/md/ so that they are more easily grepable for
hacking and not far away.  md.h is left where it is for now as there
are some uses from the outside.

Signed-off-by: Christoph Hellwig 
Signed-off-by: NeilBrown