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 [Tue, 25 Sep 2012 00:31:01 +0000 (10:31 +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 [Tue, 25 Sep 2012 00:31:00 +0000 (10:31 +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 [Tue, 25 Sep 2012 00:31:00 +0000 (10:31 +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 [Tue, 25 Sep 2012 00:30:59 +0000 (10:30 +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> Cc: stable@vger.kernel.org # 3.4+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer [Tue, 25 Sep 2012 00:30:59 +0000 (10:30 +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.
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 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>
Peter Huewe [Tue, 25 Sep 2012 00:30:54 +0000 (10:30 +1000)]
i2c: Make I2C available on UML
Remove the global dependency of the I2C subsystem on HAS_IOMEM and
move the dependency to the i2c/busses submenu, with an exception for
i2c-stub.
The generic I2C part does not need to have HAS_IOMEM set and thus now
becomes available in UML, so the I2C subsystem can now be used, e.g.
by the i2c-stub driver, for development of I2C device drivers.
[JD: Some adjustments.]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Shubhrajyoti D [Tue, 25 Sep 2012 00:30:53 +0000 (10:30 +1000)]
i2c: Convert struct i2c_msg initialization to C99 format
Convert the struct i2c_msg initialization to C99 format. This makes
maintaining and editing the code simpler. Also helps once other fields
like transferred are added in future.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Julia Lawall [Tue, 25 Sep 2012 00:30:53 +0000 (10:30 +1000)]
i2c-smbus: Convert kzalloc to devm_kzalloc
Converting kzalloc to devm_kzalloc simplifies the code and ensures that the
result, alert, is freed after the irq allocated by the subsequent
devm_request_irq. This in turn ensures that when an interrupt can be
triggered, the alert structure is still available.
The problem of a free after a devm_request_irq was found using the
following semantic match (http://coccinelle.lip6.fr/)
devm_request_irq@p1(e1,e2,...,x)
... when any
when != e2 = a
when != x = b
if (...) {
... when != e2 = c
when != x = d
free@p2(...,x,...);
...
return ...;
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Jean Delvare [Tue, 25 Sep 2012 00:30:53 +0000 (10:30 +1000)]
i2c-i801: Support SMBus multiplexing on Asus Z8 series
Add support for SMBus multiplexing on Asus Z8 motherboard series. On
these boards, the memory slots are behind a GPIO-controlled I2C
multiplexer. Models with 6 or 12 memory slots have 2 segments behind
the multiplexer, while models with 18 memory slots have 3 such
segments.
On these boards, only the memory slots are behind the multiplexer,
so it is possible to keep the autodetection mechanism.
The code is generic enough so it could work on other boards as long as
the multiplexer is controlled by GPIO pins. For other forms of
multiplexing (for example using an I2C device) additional code will be
needed.
Thanks to Asus for providing a board to develop and test this feature,
as well as all the technical information required.
At the moment, the GPIO driver must be loaded before the i2c-i801
driver, but I hope to solve this soon, using deferred probing on
the i2c-mux-gpio side.
projects / karo-tx-linux.git / log