linux-toradex.git/drivers/md/md.c, branch v2.6.27.38

md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.

2009-07-30T23:06:07+00:00

commit b8d966efd9a46a9a35beac50cbff6e30565125ef upstream.

If we try to modify one of the md/ sysfs files
  suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: remove ability to explicit set an inactive array to 'clean'.

2009-05-20T05:20:07+00:00

commit 5bf295975416f8e97117bbbcfb0191c00bc3e2b4 upstream.

Being able to write 'clean' to an 'array_state' of an inactive array
to activate it in 'clean' mode is both unnecessary and inconvenient.

It is unnecessary because the same can be achieved by writing
'active'.  This activates and array, but it still remains 'clean'
until the first write.

It is inconvenient because writing 'clean' is more often used to
cause an 'active' array to revert to 'clean' mode (thus blocking
any writes until a 'write-pending' is promoted to 'active').

Allowing 'clean' to both activate an array and mark an active array as
clean can lead to races:  One program writes 'clean' to mark the
active array as clean at the same time as another program writes
'inactive' to deactivate (stop) and active array.  Depending on which
writes first, the array could be deactivated and immediately
reactivated which isn't what was desired.

So just disable the use of 'clean' to activate an array.

This avoids a race that can be triggered with mdadm-3.0 and external
metadata, so it suitable for -stable.

Reported-by: Rafal Marszewski 
Acked-by: Dan Williams 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Allow metadata_version to be updated for externally managed metadata.

2009-02-12T17:31:12+00:00

commit ea43ddd8491feccf36267349748ea91b1194481e upstream.

For externally managed metadata, the 'metadata_version' sysfs
attribute is really just a channel for user-space programs to
communicate about how the array is being managed.
It can be useful for this to be changed while the array is active.

Normally changes to metadata_version are not permitted while the array
is active.  Change that so that if the metadata is externally managed,
the metadata_version can be changed to a different flavour of external
management.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Don't try to set an array to 'read-auto' if it is already in that state.

2009-02-12T17:31:12+00:00

commit 80268ee9270ebe4847365a7426de91d179e870d0 upstream.

'read-auto' is a variant of 'readonly' which will switch to writable
on the first write attempt.

Calling do_md_stop to set the array readonly when it is already readonly
returns an error.  So make sure not to do that.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Ensure an md array never has too many devices.

2009-02-12T17:31:01+00:00

commit de01dfadf25bf83cfe3d85c163005c4320532658 upstream.

Each different metadata format supported by md supports a
different maximum number of devices.
We really should be enforcing this maximum in the kernel, but
we aren't quite doing that properly.

We currently only enforce it at the 'hot_add' point, which is an
older interface which is not used by current userspace.

We need to also enforce it at 'add_new_disk' time for active arrays
and at 'do_md_run' time when starting a new array.

So move the test from 'hot_add' into 'bind_rdev_to_array' which is
called from both 'hot_add' and 'add_new_disk, and add a new
test in 'analyse_sbs' which is called from 'do_md_run'.

This bug (or missing feature) has been around "forever" and so
the patch is suitable for any -stable that is currently maintained.

Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Fix rdev_size_store with size == 0

2008-10-22T21:21:08+00:00

commit 7d3c6f8717ee6c2bf6cba5fa0bda3b28fbda6015 upstream

Fix rdev_size_store with size == 0.
size == 0 means to use the largest size allowed by the
underlying device and is used when modifying an active array.

This fixes a regression introduced by
 commit d7027458d68b2f1752a28016dcf2ffd0a7e8f567

Signed-off-by: Chris Webb 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: Don't wait UNINTERRUPTIBLE for other resync to finish

2008-09-19T01:49:54+00:00

When two md arrays share some block device (e.g each uses different
partitions on the one device), a resync of one array will wait for
the resync on the other to finish.

This can be a long time and as it currently waits TASK_UNINTERRUPTIBLE,
the softlockup code notices and complains.

So use TASK_INTERRUPTIBLE instead and make sure to flush signals
before calling schedule.

Signed-off-by: NeilBrown

Remove invalidate_partition call from do_md_stop.

2008-09-01T02:32:52+00:00

When stopping an md array, or just switching to read-only, we
currently call invalidate_partition while holding the mddev lock.
The main reason for this is probably to ensure all dirty buffers
are flushed (invalidate_partition calls fsync_bdev).

However if any dirty buffers are found, it will almost certainly cause
a deadlock as starting writeout will require an update to the
superblock, and performing that updates requires taking the mddev
lock - which is already held.

This deadlock can be demonstrated by running "reboot -f -n" with
a root filesystem on md/raid, and some dirty buffers in memory.

All other calls to stop an array should already happen after a flush.
The normal sequence is to stop using the array (e.g. umount) which
will cause __blkdev_put to call sync_blockdev.  Then open the
array and issue the STOP_ARRAY ioctl while the buffers are all still
clean.

So this invalidate_partition is normally a no-op, except for one case
where it will cause a deadlock.

So remove it.

This patch possibly addresses the regression recored in
   http://bugzilla.kernel.org/show_bug.cgi?id=11460
and
   http://bugzilla.kernel.org/show_bug.cgi?id=11452

though it isn't yet clear how it ever worked.


Signed-off-by: NeilBrown

md: cancel check/repair requests when recovery is needed

2008-08-07T17:02:47+00:00

If a 'repair' is requested when an array is in a position to 'recover' raid1
will perform the repair while md believes a recovery is happening.  Address
this at both ends, i.e. cancel check/repair requests upon detecting a
recover condition and do not call ->spare_active after completing a
check/repair.

Signed-off-by: Dan Williams

Allow faulty devices to be removed from a readonly array.

2008-08-05T05:56:32+00:00

Removing faulty devices from an array is a two stage process.
First the device is moved from being a part of the active array
to being similar to a spare device.  Then it can be removed
by a request from user space.

The first step is currently not performed for read-only arrays,
so the second step can never succeed.

So allow readonly arrays to remove failed devices (which aren't
blocked).

Signed-off-by: NeilBrown