start_mdmon now waits for mdmon to complete initialisation and,
importantly, listen on the socket, before continuing.
Signed-off-by: Neil Brown <neilb@suse.de>
Rather, assume that it is in the same directory from which
mdadm was run. If not, then maybe /sbin or current directory.
Signed-off-by: Neil Brown <neilb@suse.de>
If an array is being managed by mdmon, then just
write "inactive" to stop it, and let mdmon do the
final "clear". This makes sure mdmon has a chance
to read the final state and update the metadata properly.
After writing "inactive" with use "ping_monitor" to synchronise
with mdadm, then STOP the array just in case it is still running,
else we will get into an infinite loop in "mdadm -Ss".
Signed-off-by: Neil Brown <neilb@suse.de>
When a 'ping' (empty message) is sent to mdmon, we wait for
'monitor' to do a full loop to make sure it has caught up
with anything that needs doing.
This allows synchronisation between mdadm and mdmon.
Maybe monitor should signal managemon rather than managemon polling...
Signed-off-by: Neil Brown <neilb@suse.de>
Following the lead of 75ede16d. This incidentally fixes creation of a second
array by gating call to getinfo_super_imsm_volume with a valid ->current_vol.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
When creating an array in a container, print e.g.
Creating array inside ddf container /dev/whatever
rather than
Defaulting to version /md127/1 metadata
Using buffered IO risks non-atomic updates to parts of the
device that we don't actually want to write to. This isn't in
general safe.
So switch to O_DIRECT for all that IO and make sure we have
properly aligned buffers.
1/ track if there are any actual updates pending, and only
write metadata when we have changed something.
2/ when writing null virtual-configs, write full blocks,
not just the first 4 bytes. This will allow O_DIRECT
writes in a subsequent patch.
1/ close a race where multiple arrays disappear at once
and monitor isn't woken up to find out that the last one
has gone.
2/ "mdadm -Ss" needs to pause briefly for mdmon to exit.
The returned value was never used, and we don't really want
this return path anyway as writing to a pipe could conceivably
block, and the monitor must not block.
This really should be done in mdadm, not mdmon.
We ensure the device won't be suddenly commited as a hot-spare
using O_EXCL, then check the 'holders' sysfs directory
to make sure it is only in use once.
When loading the metadata for a subarray (super_by_fd), we set
->subarray to be the name read from md/metadata_version so that
getinfo_super can return info about the correct array.
With this we can differentiate between a container and
an array within the container by looking at ->subarray[0].
NeilBrown
Dan Williams