Previously it was possible to set the WRITEMOSTLY flag when
adding a device to an array, but not to clear the flag when re-adding.
This is now possible with --readwrite.
Signed-off-by: NeilBrown <neilb@suse.de>
This did not work before as we couldn't mark it clean as there would
be some parity blocks out of sync, and raid6 will not assemble a
dirty degraded array.
So make such arrays doubly degraded (the last device becomes a spare)
and clean.
array.size is 32bits and counts K. So for arrays with
more than 4Terrabytes, it can overflow.
The correct number can be read from sysfs, but there are still
a few places that use array.size and risk truncation. What is worse.
they compare a number of kilobytes with a number of sectors !!
So use get_component_size() to read the sysfs information, and be
more consistent about units.
Some kernel versions don't put a space between 'active' and '(auto-read-only)'
in /proc/mdstat. This causes a parsing problem leaving 'level' set to
NULL which causes a crash.
So synthesise a space there if it is missing, and check for 'level' to
be NULL and don't de-ref if it is.
Make sure that if --assemble find an array in the critical region
of a reshape, and cannot find the critical data to restart the
reshape, it gives an error message.
When adding new disk to an array, don't reserve so much bitmap
space that the disk cannot store the required data. (Needed when
1.x array was created with older mdadm).
From: Ian Dall <ian@beware.dropbear.id.au>
I have a small patch to mdadm which allows the write-behind amount to be
set a array grow time (instead of currently only at grow or create
time). I have tested this fairly extensively on some arrays built out of
loop back devices, and once on a real live array.
The new superblock needs to have a new disk.number. This is a bit of a hack...
Fix handling of negative bitmap offsets on 64bit hosts.
The bitmap offset is a signed 32bit number, so casting to (long)
isn't sufficient. We must cast to (int32_t).
Fix various problems with --grow --add for linear.
The code to add a drive to a live linear array had never
been tested properly and so was buggy. This tidies it up
and means that the new regression-test passes.
If two drives in a raid5 disappear at the same time, then "-Af"
will add them both in rather than just one and forcing the array
to 'clean'. This is slightly safer in some cases.
NeilBrown
Ian Dall