wc->dirty_bitmap_size is in bytes so must multiply it by 8, not by
BITS_PER_LONG, to get number of bitmap_bits.

Fixes crash in find_next_bit() that was reported:
https://bugzilla.kernel.org/show_bug.cgi?id=200819

Reported-by: edo.rus@gmail.com
Fixes: 48debafe ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm-crypt should only increase device limits, it should not decrease them.

This fixes a bug where the user could creates a crypt device with 1024
sector size on the top of scsi device that had 4096 logical block size.
The limit 4096 would be lost and the user could incorrectly send
1024-I/Os to the crypt device.

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

Quoting Documentation/device-mapper/cache.txt:

  The 'dirty' state for a cache block changes far too frequently for us
  to keep updating it on the fly.  So we treat it as a hint.  In normal
  operation it will be written when the dm device is suspended.  If the
  system crashes all cache blocks will be assumed dirty when restarted.

This got broken in commit f177940a ("dm cache metadata: switch to
using the new cursor api for loading metadata") in 4.9, which removed
the code that consulted cmd->clean_when_opened (CLEAN_SHUTDOWN on-disk
flag) when loading cache blocks.  This results in data corruption on an
unclean shutdown with dirty cache blocks on the fast device.  After the
crash those blocks are considered clean and may get evicted from the
cache at any time.  This can be demonstrated by doing a lot of reads
to trigger individual evictions, but uncache is more predictable:

  ### Disable auto-activation in lvm.conf to be able to do uncache in
  ### time (i.e. see uncache doing flushing) when the fix is applied.

  # xfs_io -d -c 'pwrite -b 4M -S 0xaa 0 1G' /dev/vdb
  # vgcreate vg_cache /dev/vdb /dev/vdc
  # lvcreate -L 1G -n lv_slowdev vg_cache /dev/vdb
  # lvcreate -L 512M -n lv_cachedev vg_cache /dev/vdc
  # lvcreate -L 256M -n lv_metadev vg_cache /dev/vdc
  # lvconvert --type cache-pool --cachemode writeback vg_cache/lv_cachedev --poolmetadata vg_cache/lv_metadev
  # lvconvert --type cache vg_cache/lv_slowdev --cachepool vg_cache/lv_cachedev
  # xfs_io -d -c 'pwrite -b 4M -S 0xbb 0 512M' /dev/mapper/vg_cache-lv_slowdev
  # xfs_io -d -c 'pread -v 254M 512' /dev/mapper/vg_cache-lv_slowdev | head -n 2
  0fe00000:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  0fe00010:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  # dmsetup status vg_cache-lv_slowdev
  0 2097152 cache 8 27/65536 128 8192/8192 1 100 0 0 0 8192 7065 2 metadata2 writeback 2 migration_threshold 2048 smq 0 rw -
                                                            ^^^^
                                7065 * 64k = 441M yet to be written to the slow device
  # echo b >/proc/sysrq-trigger

  # vgchange -ay vg_cache
  # xfs_io -d -c 'pread -v 254M 512' /dev/mapper/vg_cache-lv_slowdev | head -n 2
  0fe00000:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  0fe00010:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  # lvconvert --uncache vg_cache/lv_slowdev
  Flushing 0 blocks for cache vg_cache/lv_slowdev.
  Logical volume "lv_cachedev" successfully removed
  Logical volume vg_cache/lv_slowdev is not cached.
  # xfs_io -d -c 'pread -v 254M 512' /dev/mapper/vg_cache-lv_slowdev | head -n 2
  0fe00000:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
  0fe00010:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................

This is the case with both v1 and v2 cache pool metatata formats.

After applying this patch:

  # vgchange -ay vg_cache
  # xfs_io -d -c 'pread -v 254M 512' /dev/mapper/vg_cache-lv_slowdev | head -n 2
  0fe00000:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  0fe00010:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  # lvconvert --uncache vg_cache/lv_slowdev
  Flushing 3724 blocks for cache vg_cache/lv_slowdev.
  ...
  Flushing 71 blocks for cache vg_cache/lv_slowdev.
  Logical volume "lv_cachedev" successfully removed
  Logical volume vg_cache/lv_slowdev is not cached.
  # xfs_io -d -c 'pread -v 254M 512' /dev/mapper/vg_cache-lv_slowdev | head -n 2
  0fe00000:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  0fe00010:  bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................

Cc: stable@vger.kernel.org
Fixes: f177940a ("dm cache metadata: switch to using the new cursor api for loading metadata")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Commit ae1093be ("dm snapshot: use mutex instead of rw_semaphore")
eliminated the need to worry about read vs write locking.  So remove a
FIXME in snapshot_map() that is concerned about selectively taking a
write lock.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

copy_complete()'s processing of out_of_order_list can result in
quadratic complexity in the worst case.  As such it was the source of
consuming too much cpu and the source of significant loss in
performance.

Fix this by converting out_of_order_list to an rbtree.  This improved
a dm-snapshot test copy workload from 32 seconds to 4 seconds.
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Brett Hull <bhull@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

It was reported that softlockups occur when using dm-snapshot ontop of
slow (rbd) storage.  E.g.:

[ 4047.990647] watchdog: BUG: soft lockup - CPU#10 stuck for 22s! [kworker/10:23:26177]
...
[ 4048.034151] Workqueue: kcopyd do_work [dm_mod]
[ 4048.034156] RIP: 0010:copy_callback+0x41/0x160 [dm_snapshot]
...
[ 4048.034190] Call Trace:
[ 4048.034196]  ? __chunk_is_tracked+0x70/0x70 [dm_snapshot]
[ 4048.034200]  run_complete_job+0x5f/0xb0 [dm_mod]
[ 4048.034205]  process_jobs+0x91/0x220 [dm_mod]
[ 4048.034210]  ? kcopyd_put_pages+0x40/0x40 [dm_mod]
[ 4048.034214]  do_work+0x46/0xa0 [dm_mod]
[ 4048.034219]  process_one_work+0x171/0x370
[ 4048.034221]  worker_thread+0x1fc/0x3f0
[ 4048.034224]  kthread+0xf8/0x130
[ 4048.034226]  ? max_active_store+0x80/0x80
[ 4048.034227]  ? kthread_bind+0x10/0x10
[ 4048.034231]  ret_from_fork+0x35/0x40
[ 4048.034233] Kernel panic - not syncing: softlockup: hung tasks

Fix this by calling cond_resched() after run_complete_job()'s callout to
the dm_kcopyd_notify_fn (which is dm-snap.c:copy_callback in the above
trace).
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

policy_hint_size starts as 0 during __write_initial_superblock().  It
isn't until the policy is loaded that policy_hint_size is set in-core
(cmd->policy_hint_size).  But it never got recorded in the on-disk
superblock because __commit_transaction() didn't deal with transfering
the in-core cmd->policy_hint_size to the on-disk superblock.

The in-core cmd->policy_hint_size gets initialized by metadata_open()'s
__begin_transaction_flags() which re-reads all superblock fields.
Because the superblock's policy_hint_size was never properly stored, when
the cache was created, hints_array_available() would always return false
when re-activating a previously created cache.  This means
__load_mappings() always considered the hints invalid and never made use
of the hints (these hints served to optimize).

Another detremental side-effect of this oversight is the cache_check
utility would fail with: "invalid hint width: 0"

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

Now both check_for_space() and do_no_space_timeout() will read & write
pool->pf.error_if_no_space.  If these functions run concurrently, as
shown in the following case, the default setting of "queue_if_no_space"
can get lost.

precondition:
    * error_if_no_space = false (aka "queue_if_no_space")
    * pool is in Out-of-Data-Space (OODS) mode
    * no_space_timeout worker has been queued

CPU 0:                          CPU 1:
// delete a thin device
process_delete_mesg()
// check_for_space() invoked by commit()
set_pool_mode(pool, PM_WRITE)
    pool->pf.error_if_no_space = \
     pt->requested_pf.error_if_no_space

				// timeout, pool is still in OODS mode
				do_no_space_timeout
				    // "queue_if_no_space" config is lost
				    pool->pf.error_if_no_space = true
    pool->pf.mode = new_mode

Fix it by stopping no_space_timeout worker when switching to write mode.

Fixes: bcc696fa ("dm thin: stay in out-of-data-space mode once no_space_timeout expires")
Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm_kcopyd_copy() only ever returns 0 so there is no need for callers to
account for possible failure.  Same goes for dm_kcopyd_zero().
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The metadata low watermark threshold is set by the kernel.  But the
kernel depends on userspace to extend the thinpool metadata device when
the threshold is crossed.

Since the metadata low watermark threshold is not visible to userspace,
upon receiving an event, userspace cannot tell that the kernel wants the
metadata device extended, instead of some other eventing condition.
Making it visible (but not settable) enables userspace to affirmatively
know the kernel is asking for a metadata device extension, by comparing
metadata_low_watermark against nr_free_blocks_metadata, also reported in
status.

Current solutions like dmeventd have their own thresholds for extending
the data and metadata devices, and both devices are checked against
their thresholds on each event.  This lessens the value of the kernel-set
threshold, since userspace will either extend the metadata device sooner,
when receiving another event; or will receive the metadata lowater event
and do nothing, if dmeventd's threshold is less than the kernel's.
(This second case is dangerous. The metadata lowater event will not be
re-sent, so no further event will be generated before the metadata
device is out if space, unless some other event causes userspace to
recheck its thresholds.)
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Fixes: d284f824 ("dm writecache: support optional offset for start of device")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

In preparing to remove all stack VLA usage from the kernel[1], remove
the discouraged use of AHASH_REQUEST_ON_STACK in favor of the smaller
SHASH_DESC_ON_STACK by converting from ahash-wrapped-shash to direct
shash.  The stack allocation will be made a fixed size in a later patch
to the crypto subsystem.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.comSigned-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

This is a small simplification of dm-crypt - use wake_up_process()
instead of a wait queue in a case where only one process may be
waiting.  dm-writecache uses a similar pattern.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When using external metadata device and internal hash, recalculate the
checksums when the device is created - so that dm-integrity doesn't
have to overwrite the device.  The superblock stores the last position
when the recalculation ended, so that it is properly restarted.

Integrity tags that haven't been recalculated yet are ignored.

Also bump the target version.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Flush the journal on suspend when using separate data and metadata devices,
so that the metadata device can be discarded and the table can be reloaded
with a linear target pointing to the data device.

NOTE: the journal is deliberately not flushed when using the same device
for metadata and data, so that the journal replay code is tested.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Use version "2" in the superblock when data and metadata devices are
separate, so that the device is not accidentally read by older kernel
version.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Add the ability to store DM integrity metadata on a separate device.
This feature is activated with the option "meta_device:/dev/device".
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

A small refactoring.  Add the variable ic->start to the result
returned by get_data_sector() and not in the callers.  This is a
prerequisite for the commit that adds the ability to use an external
metadata device.
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>

dm-integrity locks a range of sectors to prevent concurrent I/O or journal
writeback.  These locks were not fair - so that many small overlapping I/Os
could starve a large I/O indefinitely.

Fix this by making the range locks fair.  The ranges that are waiting are
added to the list "wait_list".  If a new I/O overlaps some of the waiting
I/Os, it is not dispatched, but it is also added to that wait list.
Entries on the wait list are processed in first-in-first-out order, so
that an I/O can't starve indefinitely.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Decouple how dm_integrity_map_continue() responds to being out of free
sectors and when add_new_range() fails.

This has no functional change, but helps prepare for the next commit.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Early alpha processors can't write a byte or short atomically - they
read 8 bytes, modify the byte or two bytes in registers and write back
8 bytes.

The modification of the variable "suspending" may race with
modification of the variable "failed".  Fix this by changing
"suspending" to an int.

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

Add a new class for dm-delay that delays flush requests.  Previously,
flushes were delayed as writes, but it caused problems if the user
needed to create a device with one or a few slow sectors for the purpose
of testing - all flushes would be forwarded to this device and delayed,
and that skews the test results.  Fix this by allowing to select 0 delay
for flushes.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm-delay has a lot of code that is repeated for delaying read and write
bios.  Repetitive code is generally bad; refactor out the repetitive
code in preperation for adding another delay class for flush bios.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

More than one io_mode feature can be requested when creating a dm cache
device (as is: last one wins).  The io_mode selections are incompatible
with one another, we should force them to be selected exclusively.  Add
a counter to check for more than one io_mode selection.

Fixes: 629d0a8a ("dm cache metadata: add "metadata2" feature")
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Documentation/device-mapper-/thin-provisioning.txt's "Status" section no
longer reflected the current fitness level of DM thin-provisioning.
That is, DM thinp is no longer "EXPERIMENTAL".  It has since seen
considerable improvement, has been fairly widely deployed and has
performed in a robust manner.

Update Documentation to dispel concern raised by potential DM thinp
users.
Reported-by: Drew Hastings <dhastings@crucialwebhost.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Pull NVMe fixes from Christoph Hellwig:

 - fix a regression in 4.18 that causes a memory leak on probe failure
   (Keith Bush)

 - fix a deadlock in the passthrough ioctl code (Scott Bauer)

 - don't enable AENs if not supported (Weiping Zhang)

 - fix an old regression in metadata handling in the passthrough ioctl
   code (Roland Dreier)

* tag 'nvme-for-4.18' of git://git.infradead.org/nvme:
  nvme: fix handling of metadata_len for NVME_IOCTL_IO_CMD
  nvme: don't enable AEN if not supported
  nvme: ensure forward progress during Admin passthru
  nvme-pci: fix memory leak on probe failure

Pull vfs fixes from Al Viro:
 "Fix several places that screw up cleanups after failures halfway
  through opening a file (one open-coding filp_clone_open() and getting
  it wrong, two misusing alloc_file()). That part is -stable fodder from
  the 'work.open' branch.

  And Christoph's regression fix for uapi breakage in aio series;
  include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel
  definition of sigset_t, the reason for doing so in the first place had
  been bogus - there's no need to expose struct __aio_sigset in
  aio_abi.h at all"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: don't expose __aio_sigset in uapi
  ocxlflash_getfile(): fix double-iput() on alloc_file() failures
  cxl_getfile(): fix double-iput() on alloc_file() failures
  drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()

kernel_wait4() expects a userland address for status - it's only
rusage that goes as a kernel one (and needs a copyout afterwards)

[ Also, fix the prototype of kernel_wait4() to have that __user
  annotation   - Linus ]

Fixes: 92ebce5a ("osf_wait4: switch to kernel_wait4()")
Cc: stable@kernel.org # v4.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM SoC fixes from Olof Johansson:

 - Fix interrupt type on ethernet switch for i.MX-based RDU2

 - GPC on i.MX exposed too large a register window which resulted in
   userspace being able to crash the machine.

 - Fixup of bad merge resolution moving GPIO DT nodes under pinctrl on
   droid4.

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: imx6: RDU2: fix irq type for mv88e6xxx switch
  soc: imx: gpc: restrict register range for regmap access
  ARM: dts: omap4-droid4: fix dts w.r.t. pwm

Pull x86 fix from Ingo Molnar:
 "A single fix for a MCE-polling regression, which prevented the
  disabling of polling"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/MCE: Remove min interval polling limitation

Pull x86 pti fixes from Ingo Molnar:
 "An APM fix, and a BTS hardware-tracing fix related to PTI changes"

* 'x86-pti-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apm: Don't access __preempt_count with zeroed fs
  x86/events/intel/ds: Fix bts_interrupt_threshold alignment

Pull scheduler fixes from Ingo Molnar:
 "Two fixes: a stop-machine preemption fix and a SCHED_DEADLINE fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix switched_from_dl() warning
  stop_machine: Disable preemption when waking two stopper threads

Pull core kernel fixes from Ingo Molnar:
 "This is mostly the copy_to_user_mcsafe() related fixes from Dan
  Williams, and an ORC fix for Clang"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm/memcpy_mcsafe: Fix copy_to_user_mcsafe() exception handling
  lib/iov_iter: Fix pipe handling in _copy_to_iter_mcsafe()
  lib/iov_iter: Document _copy_to_iter_flushcache()
  lib/iov_iter: Document _copy_to_iter_mcsafe()
  objtool: Use '.strtab' if '.shstrtab' doesn't exist, to support ORC tables on Clang

Pull powerpc fixes from Michael Ellerman:
 "Two regression fixes, one for xmon disassembly formatting and the
  other to fix the E500 build.

  Two commits to fix a potential security issue in the VFIO code under
  obscure circumstances.

  And finally a fix to the Power9 idle code to restore SPRG3, which is
  user visible and used for sched_getcpu().

  Thanks to: Alexey Kardashevskiy, David Gibson. Gautham R. Shenoy,
  James Clarke"

* tag 'powerpc-4.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle)
  powerpc/Makefile: Assemble with -me500 when building for E500
  KVM: PPC: Check if IOMMU page is contained in the pinned physical page
  vfio/spapr: Use IOMMU pageshift rather than pagesize
  powerpc/xmon: Fix disassembly since printf changes

Pull btrfs fix from David Sterba:
 "A fix of a corruption regarding fsync and clone, under some very
  specific conditions explained in the patch.

  The fix is marked for stable 3.16+ so I'd like to get it merged now
  given the impact"

* tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix file data corruption after cloning a range and fsync

Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>