linux-stable.git/drivers/md, branch v4.12.2

dm thin: do not queue freed thin mapping for next stage processing

2017-06-27T19:14:34+00:00

process_prepared_discard_passdown_pt1() should cleanup
dm_thin_new_mapping in cases of error.

dm_pool_inc_data_range() can fail trying to get a block reference:

metadata operation 'dm_pool_inc_data_range' failed: error = -61

When dm_pool_inc_data_range() fails, dm thin aborts current metadata
transaction and marks pool as PM_READ_ONLY. Memory for thin mapping
is released as well. However, current thin mapping will be queued
onto next stage as part of queue_passdown_pt2() or passdown_endio().
This dangling thin mapping memory when processed and accessed in
next stage will lead to device mapper crashing.

Code flow without fix:
-> process_prepared_discard_passdown_pt1(m)
   -> dm_thin_remove_range()
   -> discard passdown
      --> passdown_endio(m) queues m onto next stage
   -> dm_pool_inc_data_range() fails, frees memory m
            but does not remove it from next stage queue

-> process_prepared_discard_passdown_pt2(m)
   -> processes freed memory m and crashes

One such stack:

Call Trace:
[] dm_cell_release_no_holder+0x2f/0x70 [dm_bio_prison]
[] cell_defer_no_holder+0x3c/0x80 [dm_thin_pool]
[] process_prepared_discard_passdown_pt2+0x4b/0x90 [dm_thin_pool]
[] process_prepared+0x81/0xa0 [dm_thin_pool]
[] do_worker+0xc5/0x820 [dm_thin_pool]
[] ? __schedule+0x244/0x680
[] ? pwq_activate_delayed_work+0x42/0xb0
[] process_one_work+0x153/0x3f0
[] worker_thread+0x12b/0x4b0
[] ? rescuer_thread+0x350/0x350
[] kthread+0xca/0xe0
[] ? kthread_park+0x60/0x60
[] ret_from_fork+0x25/0x30

The fix is to first take the block ref count for discarded block and
then do a passdown discard of this block. If block ref count fails,
then bail out aborting current metadata transaction, mark pool as
PM_READ_ONLY and also free current thin mapping memory (existing error
handling code) without queueing this thin mapping onto next stage of
processing. If block ref count succeeds, then passdown discard of this
block. Discard callback of passdown_endio() will queue this thin mapping
onto next stage of processing.

Code flow with fix:
-> process_prepared_discard_passdown_pt1(m)
   -> dm_thin_remove_range()
   -> dm_pool_inc_data_range()
      --> if fails, free memory m and bail out
   -> discard passdown
      --> passdown_endio(m) queues m onto next stage

Cc: stable  # v4.9+
Reviewed-by: Eduardo Valentin 
Reviewed-by: Cristian Gafton 
Reviewed-by: Anchal Agarwal 
Signed-off-by: Vallish Vaidyeshwara 
Reviewed-by: Joe Thornber 
Signed-off-by: Mike Snitzer

dm raid: fix oops on upgrading to extended superblock format

2017-06-23T16:16:15+00:00

When a RAID set was created on dm-raid version < 1.9.0 (old RAID
superblock format), all of the new 1.9.0 members of the superblock are
uninitialized (zero) -- including the device sectors member needed to
support shrinking.

All the other accesses to superblock fields new in 1.9.0 were reviewed
and verified to be properly guarded against invalid use.  The 'sectors'
member was the only one used when the superblock version is < 1.9.

Don't access the superblock's >= 1.9.0 'sectors' member unconditionally.
Also add respective comments.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm io: fix duplicate bio completion due to missing ref count

2017-06-21T16:04:50+00:00

If only a subset of the devices associated with multiple regions support
a given special operation (eg. DISCARD) then the dec_count() that is
used to set error for the region must increment the io->count.

Otherwise, when the dec_count() is called it can cause the dm-io
caller's bio to be completed multiple times.  As was reported against
the dm-mirror target that had mirror legs with a mix of discard
capabilities.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=196077
Reported-by: Zhang Yi 
Signed-off-by: Mike Snitzer

dm integrity: fix to not disable/enable interrupts from interrupt context

2017-06-21T15:45:02+00:00

Use spin_lock_irqsave and spin_unlock_irqrestore rather than
spin_{lock,unlock}_irq in submit_flush_bio().

Otherwise lockdep issues the following warning:
  DEBUG_LOCKS_WARN_ON(current->hardirq_context)
  WARNING: CPU: 1 PID: 0 at kernel/locking/lockdep.c:2748 trace_hardirqs_on_caller+0x107/0x180

Reported-by: Ondrej Kozina 
Tested-by: Ondrej Kozina 
Signed-off-by: Mike Snitzer 
Acked-by: Mikulas Patocka

Revert "dm mirror: use all available legs on multiple failures"

2017-06-15T12:39:15+00:00

This reverts commit 12a7cf5ba6c776a2621d8972c7d42e8d3d959d20.

This commit apparently attempted to fix an issue that didn't really
exist, furthermore: this commit is the source of deadlocks and crashes
seen in multiple cases related to failing the primary mirror dev while
syncing.

Reported-by: Jonathan Brassow 
Signed-off-by: Mike Snitzer

dm integrity: reject mappings too large for device

2017-06-12T21:05:55+00:00

dm-integrity would successfully create mappings with the number of
sectors greater than the provided data sector count.  Attempts to read
sectors of this mapping that were beyond the provided data sector count
would then yield run-time messages of the form "device-mapper:
integrity: Too big sector number: ...".

Fix this by emitting an error when the requested mapping size is bigger
than the provided data sector count.

Signed-off-by: Ondrej Mosnacek 
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

md: initialise ->writes_pending in personality modules.

2017-06-05T23:04:35+00:00

The new per-cpu counter for writes_pending is initialised in
md_alloc(), which is not called by dm-raid.
So dm-raid fails when md_write_start() is called.

Move the initialization to the personality modules
that need it.  This way it is always initialised when needed,
but isn't unnecessarily initialized (requiring memory allocation)
when the personality doesn't use writes_pending.

Reported-by: Heinz Mauelshagen 
Fixes: 4ad23a976413 ("MD: use per-cpu counter for writes_pending")
Signed-off-by: NeilBrown 
Signed-off-by: Shaohua Li

Merge tag 'for-4.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2017-06-02T18:50:37+00:00

Pull device mapper fixes from Mike Snitzer:

 - a DM verity fix for a mode when no salt is used

 - a fix to DM to account for the possibility that PREFLUSH or FUA are
   used without the SYNC flag if the underlying storage doesn't have a
   volatile write-cache

 - a DM ioctl memory allocation flag fix to use __GFP_HIGH to allow
   emergency forward progress (by using memory reserves as last resort)

 - a small DM integrity cleanup to use kvmalloc() instead of duplicating
   the same

* tag 'for-4.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: make flush bios explicitly sync
  dm ioctl: restore __GFP_HIGH in copy_params()
  dm integrity: use kvmalloc() instead of dm_integrity_kvmalloc()
  dm verity: fix no salt use case

md: Make flush bios explicitely sync

2017-05-31T16:25:53+00:00

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

CC: linux-raid@vger.kernel.org
CC: Shaohua Li 
Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Signed-off-by: Shaohua Li

dm: make flush bios explicitly sync

2017-05-31T14:50:23+00:00

Commit b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as
synchronous") removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

Fixes: b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Signed-off-by: Mike Snitzer