linux-toradex.git/drivers/md, branch tegra-10.9.9

dm log: userspace fix overhead_size calcuations

2010-02-23T15:37:58+00:00

commit ebfd32bba9b518d684009d9d21a56742337ca1b3 upstream.

This patch fixes two bugs that revolve around the miscalculation and
misuse of the variable 'overhead_size'.  'overhead_size' is the size of
the various header structures used during communication.

The first bug is the use of 'sizeof' with the pointer of a structure
instead of the structure itself - resulting in the wrong size being
computed.  This is then used in a check to see if the payload
(data_size) would be to large for the preallocated structure.  Since the
bug produces a smaller value for the overhead, it was possible for the
structure to be breached.  (Although the current users of the code do
not currently send enough data to trigger this bug.)

The second bug is that the 'overhead_size' value is used to compute how
much of the preallocated space should be cleared before populating it
with fresh data.  This should have simply been 'sizeof(struct cn_msg)'
not overhead_size.  The fact that 'overhead_size' was computed
incorrectly made this problem "less bad" - leaving only a pointer's
worth of space at the end uncleared.  Thus, this bug was never producing
a bad result, but still needs to be fixed - especially now that the
value is computed correctly.

Signed-off-by: Jonathan Brassow 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman

dm stripe: avoid divide by zero with invalid stripe count

2010-02-23T15:37:58+00:00

commit 781248c1b50c776a9ef4be1130f84ced1cba42fe upstream.

If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.

This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.

We now get the following error messages:
  device-mapper: table: 253:0: striped: Invalid stripe count
  device-mapper: ioctl: error adding target to table

Signed-off-by: Nikanth Karthikesan 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman

md: fix 'degraded' calculation when starting a reshape.

2010-02-23T15:37:51+00:00

commit 9eb07c259207d048e3ee8be2a77b2a4680b1edd4 upstream.

This code was written long ago when it was not possible to
reshape a degraded array.  Now it is so the current level of
degraded-ness needs to be taken in to account.  Also newly addded
devices should only reduce degradedness if they are deemed to be
in-sync.

In particular, if you convert a RAID5 to a RAID6, and increase the
number of devices at the same time, then the 5->6 conversion will
make the array degraded so the current code will produce a wrong
value for 'degraded' - "-1" to be precise.

If the reshape runs to completion end_reshape will calculate a correct
new value for 'degraded', but if a device fails during the reshape an
incorrect decision might be made based on the incorrect value of
"degraded".

This patch is suitable for 2.6.32-stable and if they are still open,
2.6.31-stable and 2.6.30-stable as well.

Reported-by: Michael Evans 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md: fix small irregularity with start_ro module parameter

2010-01-28T23:02:18+00:00

commit 0f9552b5dc4fe10da37fa3f4a4ca185d90fa41c9 upstream.

The start_ro modules parameter can be used to force arrays to be
started in 'auto-readonly' in which they are read-only until the first
write.  This ensures that no resync/recovery happens until something
else writes to the device.  This is important for resume-from-disk
off an md array.

However if an array is started 'readonly' (by writing 'readonly' to
the 'array_state' sysfs attribute) we want it to be really 'readonly',
not 'auto-readonly'.

So strengthen the condition to only set auto-readonly if the
array is not already read-only.

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

DM: Fix device mapper topology stacking

2010-01-25T18:49:41+00:00

commit b27d7f16d3c6c27345d4280a739809c1c2c4c0b5 upstream.

Make DM use bdev_stack_limits() function so that partition offsets get
taken into account when calculating alignment.  Clarify stacking
warnings.

Also remove obsolete clearing of final alignment_offset and misalignment
flag.

Signed-off-by: Martin K. Petersen 
Signed-off-by: Mike Snitzer 
Cc: Alasdair G. Kergon 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

md: Fix unfortunate interaction with evms

2010-01-06T23:03:49+00:00

commit cbd1998377504df005302ac90d49db72a48552a6 upstream.

evms configures md arrays by:
  open device
  send ioctl
  close device

for each different ioctl needed.
Since 2.6.29, the device can disappear after the 'close'
unless a significant configuration has happened to the device.
The change made by "SET_ARRAY_INFO" can too minor to stop the device
from disappearing, but important enough that losing the change is bad.

So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device
active as long as ctime is non-zero (it gets zeroed with lots of other
things when the array is stopped).

This is suitable for -stable kernels since 2.6.29.

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

dm crypt: make wipe message also wipe essiv key

2009-12-18T22:05:04+00:00

commit 542da317668c35036e8471822a564b609d05af66 upstream.

The "wipe key" message is used to wipe the volume key from memory
temporarily, for example when suspending to RAM.

But the initialisation vector in ESSIV mode is calculated from the
hashed volume key, so the wipe message should wipe this IV key too and
reinitialise it when the volume key is reinstated.

This patch adds an IV wipe method called from a wipe message callback.
ESSIV is then reinitialised using the init function added by the
last patch.

Signed-off-by: Milan Broz 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman

dm crypt: separate essiv allocation from initialisation

2009-12-18T22:05:03+00:00

commit b95bf2d3d5a48b095bffe2a0cd8c40453cf59557 upstream.

This patch separates the construction of IV from its initialisation.
(For ESSIV it is a hash calculation based on volume key.)

Constructor code now preallocates hash tfm and salt array
and saves it in a private IV structure.

The next patch requires this to reinitialise the wiped IV
without reallocating memory when resuming a suspended device.

Signed-off-by: Milan Broz 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman

dm snapshot: cope with chunk size larger than origin

2009-12-18T22:05:02+00:00

commit 8e87b9b81b3c370f7e53c1ab6e1c3519ef37a644 upstream.

Under some special conditions the snapshot hash_size is calculated as zero.
This patch instead sets a minimum value of 64, the same as for the
pending exception table.

rounddown_pow_of_two(0) is an undefined operation (it expands to shift
by -1).  init_exception_table with an argument of 0 would fail with -ENOMEM.

The way to trigger the problem is to create a snapshot with a chunk size
that is larger than the origin device.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman

dm: avoid _hash_lock deadlock

2009-12-18T22:05:02+00:00

commit 6076905b5ef39e0ea58db32583c9e0036c05e47b upstream.

Fix a reported deadlock if there are still unprocessed multipath events
on a device that is being removed.

_hash_lock is held during dev_remove while trying to send the
outstanding events.  Sending the events requests the _hash_lock
again in dm_copy_name_and_uuid.

This patch introduces a separate lock around regions that modify the
link to the hash table (dm_set_mdptr) or the name or uuid so that
dm_copy_name_and_uuid no longer needs _hash_lock.

Additionally, dm_copy_name_and_uuid can only be called if md exists
so we can drop the dm_get() and dm_put() which can lead to a BUG()
while md is being freed.

The deadlock:
 #0 [ffff8106298dfb48] schedule at ffffffff80063035
 #1 [ffff8106298dfc20] __down_read at ffffffff8006475d
 #2 [ffff8106298dfc60] dm_copy_name_and_uuid at ffffffff8824f740
 #3 [ffff8106298dfc90] dm_send_uevents at ffffffff88252685
 #4 [ffff8106298dfcd0] event_callback at ffffffff8824c678
 #5 [ffff8106298dfd00] dm_table_event at ffffffff8824dd01
 #6 [ffff8106298dfd10] __hash_remove at ffffffff882507ad
 #7 [ffff8106298dfd30] dev_remove at ffffffff88250865
 #8 [ffff8106298dfd60] ctl_ioctl at ffffffff88250d80
 #9 [ffff8106298dfee0] do_ioctl at ffffffff800418c4
#10 [ffff8106298dff00] vfs_ioctl at ffffffff8002fab9
#11 [ffff8106298dff40] sys_ioctl at ffffffff8004bdaf
#12 [ffff8106298dff80] tracesys at ffffffff8005d28d (via system_call)

Reported-by: guy keren 
Signed-off-by: Mikulas Patocka 
Signed-off-by: Alasdair G Kergon 
Signed-off-by: Greg Kroah-Hartman