Conflicts:
drivers/md/md.c
- Resolved conflict in md_update_sb
- Added extra 'NULL' arg to new instance of sysfs_get_dirent.
Signed-off-by: NeilBrown <neilb@suse.de>
The problem. When implementing a network namespace I need to be able
to have multiple network devices with the same name. Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.
What this patch does is to add an additional tag field to the
sysfs dirent structure. For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible. Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.
I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.
For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded. Which means I need
a simple race free way to setup those directories as tagged.
To achieve a reace free design all tagged directories are created
and managed by sysfs itself.
Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid
- Implement mount_ns() which returns the ns of the calling process
so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.
Everything else is left up to sysfs and the driver layer.
For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.
Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.
The work needed in sysfs is more extensive. At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent. Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.
Currently only directories which hold kobjects, and
symlinks are supported. There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Devices which know that they are spares do not really need to have
an event count that matches the rest of the array, so there are no
data-in-sync issues. It is enough that the uuid matches.
So remove the requirement that the event count is up-to-date.
We currently still write out and event count on spares, but this
allows us in a year or 3 to stop doing that completely.
Signed-off-by: NeilBrown <neilb@suse.de>
When updating the event count for a simple clean <-> dirty transition,
we try to avoid updating the spares so they can safely spin-down.
As the event_counts across an array must be +/- 1, this means
decrementing the event_count on a dirty->clean transition.
This is not always safe and we have to avoid the unsafe time.
We current do this with a misguided idea about it being safe or
not depending on whether the event_count is odd or even. This
approach only works reliably in a few common instances, but easily
falls down.
So instead, simply keep internal state concerning whether it is safe
or not, and always assume it is not safe when an array is first
assembled.
Signed-off-by: NeilBrown <neilb@suse.de>
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down. Device failure/removal
etc are still recorded on spares.
However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:
This means that the alignment between 'odd/even' and
'clean/dirty' might take a little longer to attain,
how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.
So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately. There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update). We just piggy-back on that.
Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
Level modifications change the output of mdstat. The mdmon manager
thread is interested in these events for external metadata management.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This is
- unnecessary because mddev_suspend is always followed by a call to
->stop, and each ->stop unregisters the thread, and
- a problem as it makes it awkwards to suspend and then resume a
device as we will want later.
Signed-off-by: NeilBrown <neilb@suse.de>
We used to pass the personality make_request function direct
to the block layer so the first argument had to be a queue.
But now we have the intermediary md_make_request so it makes
at lot more sense to pass a struct mddev_s.
It makes it possible to have an mddev without its own queue too.
Signed-off-by: NeilBrown <neilb@suse.de>
This moves the call to the other side of set_readonly, but that should
not be an issue.
This encapsulates in 'md_stop' all of the functionality for internally
stopping the array, leaving all the interactions with externalities
(sysfs, request_queue, gendisk) in do_md_stop.
Signed-off-by: NeilBrown <neilb@suse.de>
Using do_md_stop to set an array to read-only is a little confusing.
Now most of the common code has been factored out, split
md_set_readonly off in to a separate function.
Signed-off-by: NeilBrown <neilb@suse.de>
Further refactoring of do_md_stop.
This one requires some explanation as it takes code from different
places in do_md_stop, so some re-ordering happens.
We only get into this part of do_md_stop if there are no active opens
of the device, so no writes can be happening and the device must have
been flushed. In md_stop_writes we want to stop any internal sources
of writes - i.e. resync - and flush out the metadata.
The only code that was previously before some of this code is
code to clean up the queue, the mddev, the gendisk, or sysfs, all
of which is probably better after code that makes active changes (i.e.
triggers writes).
Signed-off-by: NeilBrown <neilb@suse.de>
do_md_stop is large and clunky, so hard to understand.
This is a first step of refactoring, pulling two simple
sub-functions out.
Signed-off-by: NeilBrown <neilb@suse.de>
As part of relaxing the binding between an mddev and gendisk,
we separate do_md_run into two functions.
md_run does all the work internal to md
do_md_run calls md_run and makes and changes to gendisk
that are required.
Signed-off-by: NeilBrown <neilb@suse.de>
We set ->changed to 1 and call check_disk_change at the end
of md_open so that bd_invalidated would be set and thus
partition rescan would happen appropriately.
Now that we call revalidate_disk directly, which sets bd_invalidates,
that indirection is no longer needed and can be removed.
Signed-off-by: NeilBrown <neilb@suse.de>
Using ->array_sectors rather than get_capacity() is more
direct and is a step towards relaxing the tight connection
between mddev and gendisk.
Signed-off-by: NeilBrown <neilb@suse.de>
While I generally prefer letting personalities do as much as possible,
given that we have a central md_make_request anyway we may as well use
it to simplify code.
Also this centralises knowledge of ->gendisk which will help later.
Signed-off-by: NeilBrown <neilb@suse.de>
Level changes can be very significant, so make sure
to notify them via sysfs.
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When metadata is being managed by user-space, md doesn't know
what the maximum number of devices allowed in an array is
so ->max_disks is 0. In this case we should allow any (+ve)
number of disks.
Signed-off-by: NeilBrown <neilb@suse.de>
Writing "none" to "../md/dev-xx/slot" removes that device
from being an active part of the array, but it didn't
set ->raid_disk to -1 to record this fact.
Signed-off-by: Maciej Trela <Maciej.Trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This was needed when sysfs files could only be 'notified'
from process context. Now that we have sys_notify_direct,
we can call it directly from an interrupt.
Signed-off-by: NeilBrown <neilb@suse.de>
Some levels expect the 'redundancy group' to be present,
others don't.
So when we change level of an array we might need to
add or remove this group.
This requires fixing up the current practice of overloading ->private
to indicate (when ->pers == NULL) that something needs to be removed.
So create a new ->to_remove to fill that role.
When changing levels, we may need to add or remove attributes. When
changing RAID5 -> RAID6, we both add and remove the same thing. It is
important to catch this and optimise it out as the removal is delayed
until a lock is released, so trying to add immediately would cause
problems.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
NeilBrown
Eric W. Biederman
Dan Williams
Maciej Trela