dm-bufio checks a watermark when it allocates a new buffer in
__bufio_new().  However, it doesn't check the watermark when the user
changes /sys/module/dm_bufio/parameters/max_cache_size_bytes.

This may result in a problem - if the watermark is high enough so that
all possible buffers are allocated and if the user lowers the value of
"max_cache_size_bytes", the watermark will never be checked against the
new value because no new buffer would be allocated.

To fix this, change __evict_old_buffers() so that it checks the
watermark.  __evict_old_buffers() is called every 30 seconds, so if the
user reduces "max_cache_size_bytes", dm-bufio will react to this change
within 30 seconds and decrease memory consumption.

Depends-on: 1b0fb5a5 ("dm bufio: avoid a possible ABBA deadlock")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

__get_memory_limit() tests if dm_bufio_cache_size changed and calls
__cache_size_refresh() if it did.  It takes dm_bufio_clients_lock while
it already holds the client lock.  However, lock ordering is violated
because in cleanup_old_buffers() dm_bufio_clients_lock is taken before
the client lock.

This results in a possible deadlock and lockdep engine warning.

Fix this deadlock by changing mutex_lock() to mutex_trylock().  If the
lock can't be taken, it will be re-checked next time when a new buffer
is allocated.

Also add "unlikely" to the if condition, so that the optimizer assumes
that the condition is false.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

I/O errors triggered by multipathd incorrectly not enabling the no-flush
flag for DM_DEVICE_SUSPEND or DM_DEVICE_RESUME are hard to debug.  Add
more logging to make it easier to debug this.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

No functional change but makes the code easier to read.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Instead of checking MPATHF_QUEUE_IF_NO_PATH,
MPATHF_SAVED_QUEUE_IF_NO_PATH and the no_flush flag to decide whether
or not to push back a request (or bio) if there are no paths available,
only clear MPATHF_QUEUE_IF_NO_PATH in queue_if_no_path() if no_flush has
not been set.  The result is that only a single bit has to be tested in
the hot path to decide whether or not a request must be pushed back and
also that m->lock does not have to be taken in the hot path.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Introduce an enumeration type for the queue mode.  This patch does
not change any functionality but makes the DM code easier to read.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Verify at runtime that __pg_init_all_paths() is called with
multipath.lock held if lockdep is enabled.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Ensure that the assumptions about the caller holding suspend_lock
are checked at runtime if lockdep is enabled.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The 'cache_size' argument of dm_block_manager_create() has never been
used.  Remove it along with the definitions of the constants passed as
the 'cache_size' argument.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Otherwise the request-based DM blk-mq request_queue will be put into
service without being properly exported via sysfs.

Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Requeuing a request immediately while path initialization is ongoing
causes high CPU usage, something that is undesired.  Hence delay
requeuing while path initialization is in progress.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If blk_get_request() fails, check whether the failure is due to a path
being removed.  If that is the case, fail the path by triggering a call
to fail_path().  This avoids that the following scenario can be
encountered while removing paths:
* CPU usage of a kworker thread jumps to 100%.
* Removing the DM device becomes impossible.

Delay requeueing if blk_get_request() returns -EBUSY or -EWOULDBLOCK,
and the queue is not dying, because in these cases immediate requeuing
is inappropriate.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

activate_path() is renamed to activate_path_work() which now calls
activate_or_offline_path().  activate_or_offline_path() will be used
by the next commit.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When calling a dm ioctl that doesn't process any data
(IOCTL_FLAGS_NO_PARAMS), the contents of the data field in struct
dm_ioctl are left initialized.  Current code is incorrectly extending
the size of data copied back to user, causing the contents of kernel
stack to be leaked to user.  Fix by only copying contents before data
and allow the functions processing the ioctl to override.

Cc: stable@vger.kernel.org
Signed-off-by: Adrian Salido <salidoa@google.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The log2 of sectors_per_block was already calculated, so we don't have
to use the ilog2 function.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

There is no need to have a duplication of the generic library, i.e. hex2bin().
Replace the open coded variant.
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm-crypt used to use separate crypto transforms for each CPU, but this
is no longer the case.  To avoid confusion, fix up obsolete comments and
rename setup_essiv_cpu().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Use of the synchronous digest API limits dm-verity to using pure
CPU based algorithm providers and rules out the use of off CPU
algorithm providers which are normally asynchronous by nature,
potentially freeing CPU cycles.

This can reduce performance per Watt in situations such as during
boot time when a lot of concurrent file accesses are made to the
protected volume.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: Eric Biggers <ebiggers3@gmail.com>
CC: Ondrej Mosnáček <omosnacek+linux-crypto@gmail.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Running dm-crypt with workqueues at the standard priority results in IO
competing for CPU time with standard user apps, which can lead to
pipeline bubbles and seriously degraded performance.  Move to using
WQ_HIGHPRI workqueues to protect against that.
Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The message "key wipe" used to wipe real key stored in crypto layer by
rewriting it with zeroes.  Since commit 28856a9e ("crypto: xts -
consolidate sanity check for keys") this no longer works in FIPS mode
for XTS.

While running in FIPS mode the crypto key part has to differ from the
tweak key.

Fixes: 28856a9e ("crypto: xts - consolidate sanity check for keys")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If blk_get_request() returns ENODEV then multipath_clone_and_map()
causes a request to be requeued immediately. This can cause a kworker
thread to spend 100% of the CPU time of a single core in
__blk_mq_run_hw_queue() and also can cause device removal to never
finish.

Avoid this by only requeuing after a delay if blk_get_request() fails.
Additionally, reduce the requeue delay.

Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When committing era metadata to disk, it doesn't always save the latest
spacemap metadata root in superblock. Due to this, metadata is getting
corrupted sometimes when reopening the device. The correct order of update
should be, pre-commit (shadows spacemap root), save the spacemap root
(newly shadowed block) to in-core superblock and then the final commit.

Cc: stable@vger.kernel.org
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm-thin does not free the discard_parent bio after all chained sub
bios finished. The following kmemleak report could be observed after
pool with discard_passdown option processes discard bios in
linux v4.11-rc7. To fix this, we drop the discard_parent bio reference
when its endio (passdown_endio) called.

unreferenced object 0xffff8803d6b29700 (size 256):
  comm "kworker/u8:0", pid 30349, jiffies 4379504020 (age 143002.776s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 f0 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81a5efd9>] kmemleak_alloc+0x49/0xa0
    [<ffffffff8114ec34>] kmem_cache_alloc+0xb4/0x100
    [<ffffffff8110eec0>] mempool_alloc_slab+0x10/0x20
    [<ffffffff8110efa5>] mempool_alloc+0x55/0x150
    [<ffffffff81374939>] bio_alloc_bioset+0xb9/0x260
    [<ffffffffa018fd20>] process_prepared_discard_passdown_pt1+0x40/0x1c0 [dm_thin_pool]
    [<ffffffffa018b409>] break_up_discard_bio+0x1a9/0x200 [dm_thin_pool]
    [<ffffffffa018b484>] process_discard_cell_passdown+0x24/0x40 [dm_thin_pool]
    [<ffffffffa018b24d>] process_discard_bio+0xdd/0xf0 [dm_thin_pool]
    [<ffffffffa018ecf6>] do_worker+0xa76/0xd50 [dm_thin_pool]
    [<ffffffff81086239>] process_one_work+0x139/0x370
    [<ffffffff810867b1>] worker_thread+0x61/0x450
    [<ffffffff8108b316>] kthread+0xd6/0xf0
    [<ffffffff81a6cd1f>] ret_from_fork+0x3f/0x70
    [<ffffffffffffffff>] 0xffffffffffffffff

Cc: stable@vger.kernel.org
Signed-off-by: Dennis Yang <dennisyang@qnap.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm_btree_find_lowest_key() is giving incorrect results.  find_key()
traverses the btree correctly for finding the highest key, but there is
an error in the way it traverses the btree for retrieving the lowest
key.  dm_btree_find_lowest_key() fetches the first key of the rightmost
block of the btree instead of fetching the first key from the leftmost
block.

Fix this by conditionally passing the correct parameter to value64()
based on the @find_highest flag.

Cc: stable@vger.kernel.org
Signed-off-by: Erez Zadok <ezk@fsl.cs.sunysb.edu>
Signed-off-by: Vinothkumar Raja <vinraja@cs.stonybrook.edu>
Signed-off-by: Nidhi Panpalia <npanpalia@cs.stonybrook.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The extra pair of parantheses is not needed and causes clang to generate
warnings about the DM_DEV_CREATE_CMD comparison in validate_params().

Also remove another double parentheses that doesn't cause a warning.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

This dummy structure definition was required for RCU macros, but it
isn't required anymore, so delete it.

The dummy definition confuses the crash tool, see:
https://www.redhat.com/archives/dm-devel/2017-April/msg00197.htmlSigned-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Previously, dm-crypt could use blocks composed of multiple 512b sectors
but it created integrity profile for each 512b sector (it padded it with
zeroes).  Fix dm-crypt so that the integrity profile is sent for each
block not each sector.

The user must use the same block size in the DM crypt and integrity
targets.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The DM integrity block size can now be 512, 1k, 2k or 4k.  Using larger
blocks reduces metadata handling overhead.  The block size can be
configured at table load time using the "block_size:<value>" option;
where <value> is expressed in bytes (defult is still 512 bytes).

It is safe to use larger block sizes with DM integrity, because the
DM integrity journal makes sure that the whole block is updated
atomically even if the underlying device doesn't support atomic writes
of that size (e.g. 4k block ontop of a 512b device).

Depends-on: 2859323e ("block: fix blk_integrity_register to use template's interval_exp if not 0")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Some coding style changes.

Fix a bug that the array test_tag has insufficient size if the digest
size of internal has is bigger than the tag size.

The function __fls is undefined for zero argument, this patch fixes
undefined behavior if the user sets zero interleave_sectors.

Fix the limit of optional arguments to 8.

Don't allocate crypt_data on the stack to avoid a BUG with debug kernel.

Rename all optional argument names to have underscores rather than
dashes.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

A dm-crypt on dm-integrity device incorrectly advertises an integrity
profile on the DM crypt device.  It can be seen in the files
"/sys/block/dm-*/integrity/*" that both dm-integrity and dm-crypt target
advertise the integrity profile.  That is incorrect, only the
dm-integrity target should advertise the integrity profile.

A general problem in DM is that if we have a DM device that depends on
another device with an integrity profile, the upper device will always
advertise the integrity profile, even when the target driver doesn't
support handling integrity data.

Most targets don't support integrity data, so we provide a whitelist of
targets that support it (linear, delay and striped).  The targets that
support passing integrity data to the lower device are marked with the
flag DM_TARGET_PASSES_INTEGRITY.  The DM core will now advertise
integrity data on a DM device only if all the targets support the
integrity data.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Also remove some unnecessary use of uninitialized_var().
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

By ignoring the sentinels the cleaner policy is able to write-back dirty
cache data much faster.  There is no reason to respect the sentinels,
which denote that a block was changed recently, when using the cleaner
policy given that the cleaner is tasked with writing back all dirty
data.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When loading metadata make sure to set/clear the dirty bits in the cache
core's dirty_bitset as well as the policy.

Otherwise the cache core is unaware that any blocks were dirty when the
cache was last shutdown.  A very serious side-effect being that the
cleaner policy would therefore never be tasked with writing back dirty
data from a cache that was in writeback mode (e.g. when switching from
smq policy to cleaner policy when decommissioning a writeback cache).

This fixes a serious data corruption bug associated with writeback mode.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Since the commit 0cf45031 ("dm raid: add support for the MD RAID0
personality"), the dm-raid subsystem can activate a RAID-0 array.
Therefore, add MD_RAID0 to the dependencies of DM_RAID, so that MD_RAID0
will be selected when DM_RAID is selected.

Fixes: 0cf45031 ("dm raid: add support for the MD RAID0 personality")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit 63c32ed4 ("dm raid: add raid4/5/6 journaling support") added
journal support to close the raid4/5/6 "write hole" -- in terms of
writethrough caching.

Introduce a "journal_mode" feature and use the new
r5c_journal_mode_set() API to add support for switching the journal
device's cache mode between write-through (the current default) and
write-back.

NOTE: If the journal device is not layered on resilent storage and it
fails, write-through mode will cause the "write hole" to reoccur.  But
if the journal fails while in write-back mode it will cause data loss
for any dirty cache entries unless resilent storage is used for the
journal.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit 3a1c1ef2 ("dm raid: enhance status interface and fixup
takeover/raid0") added new table line arguments and introduced an
ordering flaw.  The sequence of the raid10_copies and raid10_format
raid parameters got reversed which causes lvm2 userspace to fail by
falsely assuming a changed table line.

Sequence those 2 parameters as before so that old lvm2 can function
properly with new kernels by adjusting the table line output as
documented in Documentation/device-mapper/dm-raid.txt.

Also, add missing version 1.10.1 highlight to the documention.

Fixes: 3a1c1ef2 ("dm raid: enhance status interface and fixup takeover/raid0")
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit 2ded3703 ("md/r5cache: State machine for raid5-cache write
back mode") added support for "write-back" caching on the raid journal
device.

In order to allow the dm-raid target to switch between the available
"write-through" and "write-back" modes, provide a new
r5c_journal_mode_set() API.

Use the new API in existing r5c_journal_mode_store()
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Shaohua Li <shli@fb.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

sector_div is very slow, so we introduce a variable sector_shift and
use shift instead of sector_div.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

In recovery mode, we don't:
- replay the journal
- check checksums
- allow writes to the device

This mode can be used as a last resort for data recovery.  The
motivation for recovery mode is that when there is a single error in the
journal, the user should not lose access to the whole device.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>