Asias He [Tue, 25 Sep 2012 02:36:17 +0000 (10:36 +0800)]
virtio-blk: Disable callback in virtblk_done()
This reduces unnecessary interrupts that host could send to guest while
guest is in the progress of irq handling.
If one vcpu is handling the irq, while another interrupt comes, in
handle_edge_irq(), the guest will mask the interrupt via mask_msi_irq()
which is a very heavy operation that goes all the way down to host.
Use the recently-added bio front_pad field to allocate struct dm_target_io.
Prior to this patch, dm_target_io was allocated from a mempool. For each
dm_target_io, there is exactly one bio allocated from a bioset.
This patch merges these two allocations into one allocation: we create a
bioset with front_pad equal to the size of dm_target_io so that every
bio allocated from the bioset has sizeof(struct dm_target_io) bytes
before it. We allocate a bio and use the bytes before the bio as
dm_target_io.
Mike Snitzer [Thu, 27 Sep 2012 23:28:20 +0000 (09:28 +1000)]
Support discards when the pool's block size is not a power of 2.
The block layer assumes discard_granularity is a power of 2 (in
blkdev_issue_discard), so we set this to the largest power of 2 that is
a divides into the number of sectors in each block, but never less than
DATA_DEV_BLOCK_SIZE_MIN_SECTORS.
This patch eliminates the "Discard support must be disabled when the
block size is not a power of 2" constraint that was imposed in commit 55f2b8b ("dm thin: support for non power of 2 pool blocksize"). That
commit was incomplete: using a block size that is not a power of 2
shouldn't mean disabling discard support on the device completely.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Use the ACCESS_ONCE macro in dm-bufio and dm-verity where a variable
can be modified asynchronously (through sysfs) and we want to prevent
compiler optimizations that assume that the variable hasn't changed.
(See Documentation/atomic_ops.txt.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Thu, 27 Sep 2012 23:28:18 +0000 (09:28 +1000)]
The discard limits that get established for a thin-pool or thin device
may be incompatible with the pool's data device. Avoid this by checking
the discard limits of the pool's data device. If an incompatibility is
found then the pool's 'discard passdown' feature is disabled.
Change thin_io_hints to ensure that a thin device always uses the same
queue limits as its pool device.
Introduce requested_pf to track whether or not the table line originally
contained the no_discard_passdown flag and use this directly for table
output. We prepare the correct setting for discard_passdown directly in
bind_control_target (called from pool_io_hints) and store it in
adjusted_pf rather than waiting until we have access to pool->pf in
pool_preresume.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Thu, 27 Sep 2012 23:28:18 +0000 (09:28 +1000)]
A little thin discard code refactoring to make the next patch (dm thin:
fix discard support for data devices) more readable.
Pull out a couple of functions (and uses bools instead of unsigned for
features).
No functional changes.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Thu, 27 Sep 2012 23:28:18 +0000 (09:28 +1000)]
Add a safety net that will re-use the DM device's existing limits in the
event that DM device has a temporary table that doesn't have any
component devices. This is to reduce the chance that requests not
respecting the hardware limits will reach the device.
DM recalculates queue limits based only on devices which currently exist
in the table. This creates a problem in the event all devices are
temporarily removed such as all paths being lost in multipath. DM will
reset the limits to the maximum permissible, which can then assemble
requests which exceed the limits of the paths when the paths are
restored. The request will fail the blk_rq_check_limits() test when
sent to a path with lower limits, and will be retried without end by
multipath. This became a much bigger issue after v3.6 commit fe86cdcef
("block: do not artificially constrain max_sectors for stacking
drivers").
Reported-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Milan Broz [Thu, 27 Sep 2012 23:28:17 +0000 (09:28 +1000)]
Always clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
have it set. Otherwise devices with predictable characteristics may
contribute entropy.
QUEUE_FLAG_ADD_RANDOM specifies whether or not queue IO timings
contribute to the random pool.
For bio-based targets this flag is always 0 because such devices have no
real queue.
For request-based devices this flag was always set to 1 by default.
Now set it according to the flags on underlying devices. If there is at
least one device which should not contribute, set the flag to zero: If a
device, such as fast SSD storage, is not suitable for supplying entropy,
a request-based queue stacked over it will not be either.
Because the checking logic is exactly same as for the rotational flag,
share the iteration function with device_is_nonrot().
Signed-off-by: Milan Broz <mbroz@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Thu, 27 Sep 2012 23:28:17 +0000 (09:28 +1000)]
The access beyond the end of device BUG_ON that was introduced to
dm_request_fn via commit 29e4013de7ad950280e4b2208 ("dm: implement
REQ_FLUSH/FUA support for request-based dm") was an overly
drastic (but simple) response to this situation.
I have received a report that this BUG_ON was hit and now think
it would be better to use dm_kill_unmapped_request() to fail the clone
and original request with -EIO.
map_request() will assign the valid target returned by
dm_table_find_target to tio->ti. But when the target
isn't valid tio->ti is never assigned (because map_request isn't
called); so add a check for tio->ti != NULL to dm_done().
Reported-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # v2.6.37+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Thu, 27 Sep 2012 23:28:17 +0000 (09:28 +1000)]
When there are no paths and multipath receives an ioctl, it waits until
a path becomes available. This behaviour is incorrect if the
"queue_if_no_path" setting was not specified, as then the ioctl should
be rejected immediately, which this patch now does.
commit 35991652b ("dm mpath: allow ioctls to trigger pg init") should
have checked if queue_if_no_path was configured before queueing IO.
Checking for the queue_if_no_path feature, like is done in map_io(),
allows the following table load to work without blocking in the
multipath_ioctl retry loop:
Mike Snitzer [Thu, 27 Sep 2012 23:28:16 +0000 (09:28 +1000)]
The dm thin pool target claims to support the zeroing of discarded
data areas. This turns out to be incorrect when processing discards
that do not exactly cover a complete number of blocks, so the target
must always set discard_zeroes_data_unsupported.
The thin pool target will zero blocks when they are allocated if the
skip_block_zeroing feature is not specified. The block layer
may send a discard that only partly covers a block. If a thin pool
block is partially discarded then there is no guarantee that the
discarded data will get zeroed before it is accessed again.
Due to this, thin devices cannot claim discards will always zero data.
Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org # 3.4+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Eric Dumazet [Wed, 26 Sep 2012 01:39:20 +0000 (01:39 +0000)]
ipv6: gre: remove ip6gre_header_parse()
dev_parse_header() callers provide 8 bytes of storage,
so it's not possible to store an IPv6 address.
Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull one more arm-soc bugfix from Olof Johansson:
"Here's a bugfix for orion5x. Without this, PCI doesn't initialize
properly because of too small coherent pool to cover the allocations
needed.
A similar fix has already been done on kirkwood."
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: Orion5x: Fix too small coherent pool.
Merge tag 'gpio-fixes-v3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO fix from Linus Walleij:
"A late GPIO fix: Roland Stigge found a problem in the LPC32xx driver
where a callback ignores one of its arguments. It needs to go into
stable too so sending this upstream immediately."
* tag 'gpio-fixes-v3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio-lpc32xx: Fix value handling of gpio_direction_output()
Merge tag 'md-3.6-fixes' of git://neil.brown.name/md
Pull two md bugfixes from NeilBrown:
"One (missing spinlock init) was only introduced recently. The other
has been present as long as raid10 has been supported, so is tagged
for -stable."
* tag 'md-3.6-fixes' of git://neil.brown.name/md:
md/raid10: fix "enough" function for detecting if array is failed.
md/raid5: add missing spin_lock_init.
Pull EDAC fixes from Mauro Carvalho Chehab:
"Three edac fixes at the memory enumeration logic:
- i3200_edac: Fixes a regression at the memory rank size, when the
memorias are dual-rank;
- i5000_edac: Fix a longstanding bug when calculating the memory
size: before Kernel 3.6, the memory size were right only
with one specific configuration;
- sb_edac: Fixes a bug since the initial release of the driver:
with 16GB DIMMs, there's an overflow at the memory size,
causing the number of pages per dimm (an unsigned value)
to have the highest bit equal to 1, effectively mangling
the memory size.
The third bug can potentially affect the error decoding logic as well."
* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac:
sb_edac: Avoid overflow errors at memory size calculation
i5000: Fix the memory size calculation with 2R memories
i3200_edac: Fix memory rank size
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