The current model for creating arrays involves writing
a superblock to each device in the array.
With containers (as with DDF), that model doesn't work.
Every device in the container may need to be updated
for an array made from just some the devices in a container.
So instead of calling write_init_super for each device,
we call it once for the array and have it iterate over
all the devices in the array.
To help with this, ->add_to_super now passes in an 'fd' and name for
the device. These get saved for use by write_init_super. So
add_to_super takes ownership of the fd, and write_init_super will
close it.
This information is stored in the new 'info' field of supertype.
As part of this, write_init_super now removes any old traces of raid
metadata rather than doing this in common code.
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.
Fixes Debian Bug 442874
When we discover that we can 're-add' a drive, we forget to check the
write-mostly flag.
This highlights the fact that you cannot turn 'off' the write-mostly
flag at this point. I wonder if that is a problem...
From: Luca Berra <bluca@comedia.it>
- Fix a bug where mdassemble didn't close a filedescriptor and so couldn't assembele
stacked arrays.
- Allow mdassemble, when run a second time, to mark all arrays as writable.
This is useful if they are started read-only as is best at boot-time.
In 2.6.17 (and prior), the dev_number is ignored when a device
is added to an active array. Rather the first free number is used.
So we work around this by making sure we use the first free
number for dev_number.
Description...
The following patch makes it possible to tag a device as write-mostly on
--add and --re-add with a non-persistent superblock array. Previously,
this was not working.
Signed-Off-By: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Neil Brown <neilb@suse.de>
As spared don't have a position in the raid array with verion-1 superblocks,
we need to handle them a bit differently.
Signed-off-by: Neil Brown <neilb@suse.de>
Support "--build"ing arrays with bitmaps.
hot-removal of bitmaps
--re-add of drives recently removed.
assorted extra tests
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Currently this includes
--write-behind to set level of write-behind supported
--write-mostly to flag devices as write-mostly.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
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>