For RAID10, we must have head/tail space for reshape.
For RAID4/5/6 we can use a spare or a backup file.
So make that distinction.
Signed-off-by: NeilBrown <neilb@suse.de>
When changing the chunksize of an array, the new chunksize must
divide the device size.
If it doesn't we report a very brief message.
Make this message a bit longer and suggest a way forward be reducing
the size of the array.
Reported-by: Mark Knecht <markknecht@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
There are now 3 places which change level.
And they all do it slightly differently with different
messages etc.
Make a single function for this and use it.
Signed-off-by: NeilBrown <neilb@suse.de>
When converting to RAID0, all spares and non-data drives
need to be removed first.
It is possible that the first HOT_REMOVE_DISK will fail because the
personality hasn't let go of it yet, so retry a few times.
Signed-off-by: NeilBrown <neilb@suse.de>
After changing the level, the meaning of layout numbers changes,
so we will keeping a new_layout value around can cause later confusion.
Signed-off-by: NeilBrown <neilb@suse.de>
This means it will be set for a "--data-offset" only reshape so that
case doesn't complain that the array is getting smaller.
Signed-off-by: NeilBrown <neilb@suse.de>
1/ ignore failed devices - obviously
2/ We need to tell the kernel which direction the reshape should
progress even if we didn't choose the particular data_offset
to use.
Signed-off-by: NeilBrown <neilb@suse.de>
Setting new_offset can fail if the v1.x "data_size" is too small.
So if that happens, try increasing it first by writing "0".
That can fail on spare devices due to a kernel bug, so if it doesn't
try writing the correct number of sectors.
Signed-off-by: NeilBrown <neilb@suse.de>
Some people want to create truely enormous arrays.
As we sometimes need to hold one file descriptor for each
device, this can hit the NOFILE limit.
So raise the limit if it ever looks like it might be a problem.
Signed-off-by: NeilBrown <neilb@suse.de>
It is possible that the devices in an array have different sizes, and
different data_offsets. So the 'before_space' and 'after_space' may
be different from drive to drive.
Any decisions about how much to change the data_offset must work on
all devices, so must be based on the minimum available space on
any devices.
So find this minimum first, then do the calculation.
Signed-off-by: NeilBrown <neilb@suse.de>
If space_after and space_before are zero (the default) then assume that
metadata doesn't support changing data_offset.
Signed-off-by: NeilBrown <neilb@suse.de>
If we can modify the data_offset, we can avoid doing any backups at all.
If we can't fall back on old approach - but not if --data-offset
was requested.
Signed-off-by: NeilBrown <neilb@suse.de>
raid10 currently uses the 'backup_blocks' field to store something
else: a minimum offset change.
This is bad practice, we will shortly need to have both for RAID5/6,
so make a separate field.
Signed-off-by: NeilBrown <neilb@suse.de>
For RAID5, not being able to set new_data_offset because of
old kernel is not a problem. So make this fatal on for RAID10.
Also remove an unused assignment to 'rv'.
Signed-off-by: NeilBrown <neilb@suse.de>
We widely use a "devnum" which is 0 or +ve for md%d devices
and -ve for md_d%d devices.
But I want to be able to use md_%s device names.
So get rid of devnum (a number) and use devnm (a 32char string).
eg.
md0
md_d2
md_home
Signed-off-by: NeilBrown <neilb@suse.de>
As 'layout' doesn't map neatly from RAID4 to RAID5, we need to
set it correctly for RAID4.
Also, when no reshape is needed we should set re->level to the final
desired level.
Signed-off-by: NeilBrown <neilb@suse.de>
commit 1f9b0e2845
Grow - be careful about 'delayed' reshapes.
Introduced a bug where a list of devices longer than 1
would cause an infinite loop. Oops.
Signed-off-by: NeilBrown <neilb@suse.de>
It fixes the following uninitialized variables compilation-time error:
WARN - Grow.c: In function ‘reshape_array’:
WARN - Grow.c:2413:21: error: ‘min_space_after’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
WARN - Grow.c:2376:39: note: ‘min_space_after’ was declared here
WARN - Grow.c:2414:22: error: ‘min_space_before’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
WARN - Grow.c:2376:21: note: ‘min_space_before’ was declared here
WARN - cc1: all warnings being treated as errors
WARN - make: *** [Grow.o] Error 1
It occurs during compilation of mdadm on Fedora 17.
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Commit 5da9ab9874
Grow_reshape re-factor
in mdadm-3.2 broke conversion from RAID5 and RAID1 - and we
never noticed.
This fixes it.
Signed-off-by: NeilBrown <neilb@suse.de>
As it was the code would crash due to "mdstat" being NULL.
Code is now more sane, but hasn't been tested on an array that
needs to grow.
Signed-off-by: NeilBrown <neilb@suse.de>
When reducing the number of devices in a RAID10, we increase the
data offset to avoid the need for backup area.
If there is no room at the end of the device to allow this, we need
to first reduce the component size of each device. However if there
is room, we don't want to insist on that, otherwise growing then
shrinking the array would not be idempotent.
So find the min before/after space before analysing a RAID10 for
reshape, and if the after space is insufficient, reduce the total size
of the array and the component size accordingly.
Signed-off-by: NeilBrown <neilb@suse.de>
RAID10 reshape requires that data_offset be changed.
So we only allow it if the new_data_offset attribute is available,
and we compute a suitable change in data offset.
Signed-off-by: NeilBrown <neilb@suse.de>
This can be used to over-ride the automatic assignment of
data offset.
For --create, it is useful to re-create old arrays where different
defaults applied.
For --grow it may be able to force a reshape in the reverse direction.
Signed-off-by: NeilBrown <neilb@suse.de>
If multiple reshapes are activated on the same devices (different
partitions) then one might be forced to wait for the other to
complete.
As reshaping suspends access to small sections of the array
at time, this cause a region to be suspended for a long time,
which isn't good.
To try to detect this and don't start suspending until
the reshape is actually happening.
This is only effective on 3.7 and later as prior kernels
don't report when the delayed reshape can progress. For
the earlier kernels, just give a warning.
Signed-off-by; NeilBrown <neilb@suse.de>
NeilBrown
Lukasz Dorau