linux-stable.git/drivers/md/dm-crypt.c, branch v4.7

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2016-03-17T18:22:54+00:00

Pull crypto update from Herbert Xu:
"Here is the crypto update for 4.6:

API:
- Convert remaining crypto_hash users to shash or ahash, also convert
blkcipher/ablkcipher users to skcipher.
- Remove crypto_hash interface.
- Remove crypto_pcomp interface.
- Add crypto engine for async cipher drivers.
- Add akcipher documentation.
- Add skcipher documentation.

Algorithms:
- Rename crypto/crc32 to avoid name clash with lib/crc32.
- Fix bug in keywrap where we zero the wrong pointer.

Drivers:
- Support T5/M5, T7/M7 SPARC CPUs in n2 hwrng driver.
- Add PIC32 hwrng driver.
- Support BCM6368 in bcm63xx hwrng driver.
- Pack structs for 32-bit compat users in qat.
- Use crypto engine in omap-aes.
- Add support for sama5d2x SoCs in atmel-sha.
- Make atmel-sha available again.
- Make sahara hashing available again.
- Make ccp hashing available again.
- Make sha1-mb available again.
- Add support for multiple devices in ccp.
- Improve DMA performance in caam.
- Add hashing support to rockchip"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (116 commits)
crypto: qat - remove redundant arbiter configuration
crypto: ux500 - fix checks of error code returned by devm_ioremap_resource()
crypto: atmel - fix checks of error code returned by devm_ioremap_resource()
crypto: qat - Change the definition of icp_qat_uof_regtype
hwrng: exynos - use __maybe_unused to hide pm functions
crypto: ccp - Add abstraction for device-specific calls
crypto: ccp - CCP versioning support
crypto: ccp - Support for multiple CCPs
crypto: ccp - Remove check for x86 family and model
crypto: ccp - memset request context to zero during import
lib/mpi: use "static inline" instead of "extern inline"
lib/mpi: avoid assembler warning
hwrng: bcm63xx - fix non device tree compatibility
crypto: testmgr - allow rfc3686 aes-ctr variants in fips mode.
crypto: qat - The AE id should be less than the maximal AE number
lib/mpi: Endianness fix
crypto: rockchip - add hash support for crypto engine in rk3288
crypto: xts - fix compile errors
crypto: doc - add skcipher API documentation
crypto: doc - update AEAD AD handling
...

dm: rename target's per_bio_data_size to per_io_data_size

2016-02-23T03:34:37+00:00

Request-based DM will also make use of per_bio_data_size.

Signed-off-by: Mike Snitzer

dm crypt: Use skcipher and ahash

2016-01-27T12:35:48+00:00

This patch replaces uses of ablkcipher with skcipher, and the long
obsolete hash interface with ahash.

Signed-off-by: Herbert Xu

dm crypt: fix a possible hang due to race condition on exit

2015-11-19T18:38:30+00:00

A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE),
__add_wait_queue, spin_unlock_irq and then tests kthread_should_stop().
It is possible that the processor reorders memory accesses so that
kthread_should_stop() is executed before __set_current_state().  If such
reordering happens, there is a possible race on thread termination:

CPU 0:
calls kthread_should_stop()
	it tests KTHREAD_SHOULD_STOP bit, returns false
CPU 1:
calls kthread_stop(cc->write_thread)
	sets the KTHREAD_SHOULD_STOP bit
	calls wake_up_process on the kernel thread, that sets the thread
	state to TASK_RUNNING
CPU 0:
sets __set_current_state(TASK_INTERRUPTIBLE)
spin_unlock_irq(&cc->write_thread_wait.lock)
schedule() - and the process is stuck and never terminates, because the
	state is TASK_INTERRUPTIBLE and wake_up_process on CPU 1 already
	terminated

Fix this race condition by using a new flag DM_CRYPT_EXIT_THREAD to
signal that the kernel thread should exit.  The flag is set and tested
while holding cc->write_thread_wait.lock, so there is no possibility of
racy access to the flag.

Also, remove the unnecessary set_task_state(current, TASK_RUNNING)
following the schedule() call.  When the process was woken up, its state
was already set to TASK_RUNNING.  Other kernel code also doesn't set the
state to TASK_RUNNING following schedule() (for example,
do_wait_for_common in completion.c doesn't do it).

Fixes: dc2676210c42 ("dm crypt: offload writes to thread")
Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Mike Snitzer

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

2015-11-07T01:50:42+00:00

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Vitaly Wool 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()

2015-10-31T23:06:00+00:00

Remove DM's unneeded NULL tests before calling these destroy functions,
now that they check for NULL, thanks to these v4.3 commits:
3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()")
4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()")

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// 
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Mike Snitzer

dm crypt: constrain crypt device's max_segment_size to PAGE_SIZE

2015-09-14T16:04:24+00:00

Setting the dm-crypt device's max_segment_size to PAGE_SIZE is an
unfortunate constraint that is required to avoid the potential for
exceeding dm-crypt's underlying device's max_segments limits -- due to
crypt_alloc_buffer() possibly allocating pages for the encryption bio
that are not as physically contiguous as the original bio.

It is interesting to note that this problem was already fixed back in
2007 via commit 91e106259 ("dm crypt: use bio_add_page").  But Linux 4.0
commit cf2f1abfb ("dm crypt: don't allocate pages for a partial
request") regressed dm-crypt back to _not_ using bio_add_page().  But
given dm-crypt's cpu parallelization changes all depend on commit
cf2f1abfb's abandoning of the more complex io fragments processing that
dm-crypt previously had we cannot easily go back to using
bio_add_page().

So all said the cleanest way to resolve this issue is to fix dm-crypt to
properly constrain the original bios entering dm-crypt so the encryption
bios that dm-crypt generates from the original bios are always
compatible with the underlying device's max_segments queue limits.

It should be noted that technically Linux 4.3 does _not_ need this fix
because of the block core's new late bio-splitting capability.  But, it
is reasoned, there is little to be gained by having the block core split
the encrypted bio that is composed of PAGE_SIZE segments.  That said, in
the future we may revert this change.

Fixes: cf2f1abfb ("dm crypt: don't allocate pages for a partial request")
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=104421
Suggested-by: Jeff Moyer 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org # 4.0+

Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2015-09-02T23:35:26+00:00

Pull device mapper update from Mike Snitzer:

 - a couple small cleanups in dm-cache, dm-verity, persistent-data's
   dm-btree, and DM core.

 - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio
   prison cells

 - a 4.2-stable fix that adds feature reporting for the dm-stats
   features added in 4.2

 - improve DM-snapshot to not invalidate the on-disk snapshot if
   snapshot device write overflow occurs; but a write overflow triggered
   through the origin device will still invalidate the snapshot.

 - optimize DM-thinp's async discard submission a bit now that late bio
   splitting has been included in block core.

 - switch DM-cache's SMQ policy lock from using a mutex to a spinlock;
   improves performance on very low latency devices (eg. NVMe SSD).

 - document DM RAID 4/5/6's discard support

[ I did not pull the slab changes, which weren't appropriate for this
  tree, and weren't obviously the right thing to do anyway.  At the very
  least they need some discussion and explanation before getting merged.

  Because not pulling the actual tagged commit but doing a partial pull
  instead, this merge commit thus also obviously is missing the git
  signature from the original tag ]

* tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix use after freeing migrations
  dm cache: small cleanups related to deferred prison cell cleanup
  dm cache: fix leaking of deferred bio prison cells
  dm raid: document RAID 4/5/6 discard support
  dm stats: report precise_timestamps and histogram in @stats_list output
  dm thin: optimize async discard submission
  dm snapshot: don't invalidate on-disk image on snapshot write overflow
  dm: remove unlikely() before IS_ERR()
  dm: do not override error code returned from dm_get_device()
  dm: test return value for DM_MAPIO_SUBMITTED
  dm verity: remove unused mempool
  dm cache: move wake_waker() from free_migrations() to where it is needed
  dm btree remove: remove unused function get_nr_entries()
  dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()
  dm cache policy smq: change the mutex to a spinlock

block: kill merge_bvec_fn() completely

2015-08-13T18:31:57+00:00

As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe 
Cc: Lars Ellenberg 
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: dm-devel@redhat.com
Cc: Neil Brown 
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig 
Cc: "Martin K. Petersen" 
Acked-by: NeilBrown  (for the 'md' bits)
Acked-by: Mike Snitzer 
Signed-off-by: Kent Overstreet 
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park 
Signed-off-by: Ming Lin 
Signed-off-by: Jens Axboe

dm: do not override error code returned from dm_get_device()

2015-08-12T15:32:21+00:00

Some of the device mapper targets override the error code returned by
dm_get_device() and return either -EINVAL or -ENXIO.  There is nothing
gained by this override.  It is better to propagate the returned error
code unchanged to caller.

This work was motivated by hitting an issue where the underlying device
was busy but -EINVAL was being returned.  After this change we get
-EBUSY instead and it is easier to figure out the problem.

Signed-off-by: Vivek Goyal 
Signed-off-by: Mike Snitzer