So if the array with minor number matching the name of a new array
already exists, just assemble with a different minor number.
Signed-off-by: NeilBrown <neilb@suse.de>
Rather than appending the md minor number, we now append a small
sequence number to make sure name in /dev/md/ that aren't LOCAL are
unique. As the map file is locked while we do this, we are sure
of no losing any races.
Signed-off-by: NeilBrown <neilb@suse.de>
This reflect that fact that more often than not it is creating things
in /dev, and allows for a new open_mddev which does just that.
Signed-off-by: NeilBrown <neilb@suse.de>
If a foreign (i.e. not known to be local) array is discovered
by --incremental assembly, we now assemble it. However we ignore
any name information in the array so as not to potentially create
a name that conflict with a 'local' array.
Also, foreign arrays are always assembled 'read-auto' to avoid writing
anything until the array is actually used.
Signed-off-by: NeilBrown <neilb@suse.de>
Fix on call that passed an invalid mode to open
Don't pass a third arg unless we also pass O_CREAT
Use symbolic args for 2nd and 3rd args
Signed-off-by: Doug Ledford <dledford@redhat.com>
From: Bill Nottingham <notting@redhat.com>
mdadm --incremental doesn't really do any locking. If you get multiple
events in parallel for the same device (that has not yet started), they
will all go down the path to create the array. One will succeed, the
rest will have SET_ARRAY_INFO die with -EBUSY (md: array mdX already has disks!)
and will exit without adding the disk.
Original bug report is: https://bugzilla.redhat.com/show_bug.cgi?id=433932
This is solved by adding very very rudimentary locking. Incremental() now
opens the device with O_EXCL to ensure only one invocation is frobbing the
array at once. A simple loop just tries to open 5 times a second for 5
seconds. If the array stays locked that long, you probably have bigger
issues.
So when you say auto=md or auto=part in mdadm.conf, it give a preference
for type of array, but standard name will override.
But --auto=md is more insistant.
FIXME I'm not at all happy about handling of names that already exist.
I don't think that should be removed if the device is active.
Signed-off-by: Neil Brown <neilb@suse.de>
This allows for larger device number if glibc supports
it (requires 2.3.3).
Also fail before creating larger device number if glibc
support isn't present.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
