linux.git/drivers/md/dm-raid.c, branch v4.12

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

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

2017-05-03T17:31:20+00:00

Pull device mapper updates from Mike Snitzer:

 - A major update for DM cache that reduces the latency for deciding
   whether blocks should migrate to/from the cache. The bio-prison-v2
   interface supports this improvement by enabling direct dispatch of
   work to workqueues rather than having to delay the actual work
   dispatch to the DM cache core. So the dm-cache policies are much more
   nimble by being able to drive IO as they see fit. One immediate
   benefit from the improved latency is a cache that should be much more
   adaptive to changing workloads.

 - Add a new DM integrity target that emulates a block device that has
   additional per-sector tags that can be used for storing integrity
   information.

 - Add a new authenticated encryption feature to the DM crypt target
   that builds on the capabilities provided by the DM integrity target.

 - Add MD interface for switching the raid4/5/6 journal mode and update
   the DM raid target to use it to enable aid4/5/6 journal write-back
   support.

 - Switch the DM verity target over to using the asynchronous hash
   crypto API (this helps work better with architectures that have
   access to off-CPU algorithm providers, which should reduce CPU
   utilization).

 - Various request-based DM and DM multipath fixes and improvements from
   Bart and Christoph.

 - A DM thinp target fix for a bio structure leak that occurs for each
   discard IFF discard passdown is enabled.

 - A fix for a possible deadlock in DM bufio and a fix to re-check the
   new buffer allocation watermark in the face of competing admin
   changes to the 'max_cache_size_bytes' tunable.

 - A couple DM core cleanups.

* tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits)
  dm bufio: check new buffer allocation watermark every 30 seconds
  dm bufio: avoid a possible ABBA deadlock
  dm mpath: make it easier to detect unintended I/O request flushes
  dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()
  dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH
  dm: introduce enum dm_queue_mode to cleanup related code
  dm mpath: verify __pg_init_all_paths locking assumptions at runtime
  dm: verify suspend_locking assumptions at runtime
  dm block manager: remove an unused argument from dm_block_manager_create()
  dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()
  dm mpath: delay requeuing while path initialization is in progress
  dm mpath: avoid that path removal can trigger an infinite loop
  dm mpath: split and rename activate_path() to prepare for its expanded use
  dm ioctl: prevent stack leak in dm ioctl call
  dm integrity: use previously calculated log2 of sectors_per_block
  dm integrity: use hex2bin instead of open-coded variant
  dm crypt: replace custom implementation of hex2bin()
  dm crypt: remove obsolete references to per-CPU state
  dm verity: switch to using asynchronous hash crypto API
  dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues
  ...

Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block

2017-05-01T17:39:57+00:00

Pull block layer updates from Jens Axboe:

 - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ
   was initially a fork of CFQ, but subsequently changed to implement
   fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant
   to be used on desktop type single drives, providing good fairness.
   From Paolo.

 - Add Kyber IO scheduler. This is a full multiqueue aware scheduler,
   using a scalable token based algorithm that throttles IO based on
   live completion IO stats, similary to blk-wbt. From Omar.

 - A series from Jan, moving users to separately allocated backing
   devices. This continues the work of separating backing device life
   times, solving various problems with hot removal.

 - A series of updates for lightnvm, mostly from Javier. Includes a
   'pblk' target that exposes an open channel SSD as a physical block
   device.

 - A series of fixes and improvements for nbd from Josef.

 - A series from Omar, removing queue sharing between devices on mostly
   legacy drivers. This helps us clean up other bits, if we know that a
   queue only has a single device backing. This has been overdue for
   more than a decade.

 - Fixes for the blk-stats, and improvements to unify the stats and user
   windows. This both improves blk-wbt, and enables other users to
   register a need to receive IO stats for a device. From Omar.

 - blk-throttle improvements from Shaohua. This provides a scalable
   framework for implementing scalable priotization - particularly for
   blk-mq, but applicable to any type of block device. The interface is
   marked experimental for now.

 - Bucketized IO stats for IO polling from Stephen Bates. This improves
   efficiency of polled workloads in the presence of mixed block size
   IO.

 - A few fixes for opal, from Scott.

 - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics.
   From a variety of folks, mostly Sagi and James Smart.

 - A series from Bart, improving our exposed info and capabilities from
   the blk-mq debugfs support.

 - A series from Christoph, cleaning up how handle WRITE_ZEROES.

 - A series from Christoph, cleaning up the block layer handling of how
   we track errors in a request. On top of being a nice cleanup, it also
   shrinks the size of struct request a bit.

 - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was
   never used by platforms, and the latter has outlived it's usefulness.

 - Various little bug fixes and cleanups from a wide variety of folks.

* 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits)
  block: hide badblocks attribute by default
  blk-mq: unify hctx delay_work and run_work
  block: add kblock_mod_delayed_work_on()
  blk-mq: unify hctx delayed_run_work and run_work
  nbd: fix use after free on module unload
  MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler
  blk-mq-sched: alloate reserved tags out of normal pool
  mtip32xx: use runtime tag to initialize command header
  scsi: Implement blk_mq_ops.show_rq()
  blk-mq: Add blk_mq_ops.show_rq()
  blk-mq: Show operation, cmd_flags and rq_flags names
  blk-mq: Make blk_flags_show() callers append a newline character
  blk-mq: Move the "state" debugfs attribute one level down
  blk-mq: Unregister debugfs attributes earlier
  blk-mq: Only unregister hctxs for which registration succeeded
  blk-mq-debugfs: Rename functions for registering and unregistering the mq directory
  blk-mq: Let blk_mq_debugfs_register() look up the queue name
  blk-mq: Register /queue/mq after having registered /queue
  ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset
  ide-pm: always pass 0 error to __blk_end_request_all
  ..

block: remove the discard_zeroes_data flag

2017-04-08T17:25:38+00:00

Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

dm raid: fix NULL pointer dereference for raid1 without bitmap

2017-03-31T15:05:54+00:00

Commit 4257e08 ("dm raid: support to change bitmap region size")
introduced a bitmap resize call during preresume phase. User can create
a DM device with "raid" target configured as raid1 with no metadata
devices to hold superblock/bitmap info. It can be achieved using the
following sequence:

  truncate -s 32M /dev/shm/raid-test
  LOOP=$(losetup --show -f /dev/shm/raid-test)
  dmsetup create raid-test-linear0 --table "0 1024 linear $LOOP 0"
  dmsetup create raid-test-linear1 --table "0 1024 linear $LOOP 1024"
  dmsetup create raid-test --table "0 1024 raid raid1 1 2048 2 - /dev/mapper/raid-test-linear0 - /dev/mapper/raid-test-linear1"

This results in the following crash:

[ 4029.110216] device-mapper: raid: Ignoring chunk size parameter for RAID 1
[ 4029.110217] device-mapper: raid: Choosing default region size of 4MiB
[ 4029.111349] md/raid1:mdX: active with 2 out of 2 mirrors
[ 4029.114770] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[ 4029.114802] IP: bitmap_resize+0x25/0x7c0 [md_mod]
[ 4029.114816] PGD 0
…
[ 4029.115059] Hardware name: Aquarius Pro P30 S85 BUY-866/B85M-E, BIOS 2304 05/25/2015
[ 4029.115079] task: ffff88015cc29a80 task.stack: ffffc90001a5c000
[ 4029.115097] RIP: 0010:bitmap_resize+0x25/0x7c0 [md_mod]
[ 4029.115112] RSP: 0018:ffffc90001a5fb68 EFLAGS: 00010246
[ 4029.115127] RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000000
[ 4029.115146] RDX: 0000000000000000 RSI: 0000000000000400 RDI: 0000000000000000
[ 4029.115166] RBP: ffffc90001a5fc28 R08: 0000000800000000 R09: 00000008ffffffff
[ 4029.115185] R10: ffffea0005661600 R11: ffff88015cc29a80 R12: ffff88021231f058
[ 4029.115204] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 4029.115223] FS:  00007fe73a6b4740(0000) GS:ffff88021ea80000(0000) knlGS:0000000000000000
[ 4029.115245] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4029.115261] CR2: 0000000000000030 CR3: 0000000159a74000 CR4: 00000000001426e0
[ 4029.115281] Call Trace:
[ 4029.115291]  ? raid_iterate_devices+0x63/0x80 [dm_raid]
[ 4029.115309]  ? dm_table_all_devices_attribute.isra.23+0x41/0x70 [dm_mod]
[ 4029.115329]  ? dm_table_set_restrictions+0x225/0x2d0 [dm_mod]
[ 4029.115346]  raid_preresume+0x81/0x2e0 [dm_raid]
[ 4029.115361]  dm_table_resume_targets+0x47/0xe0 [dm_mod]
[ 4029.115378]  dm_resume+0xa8/0xd0 [dm_mod]
[ 4029.115391]  dev_suspend+0x123/0x250 [dm_mod]
[ 4029.115405]  ? table_load+0x350/0x350 [dm_mod]
[ 4029.115419]  ctl_ioctl+0x1c2/0x490 [dm_mod]
[ 4029.115433]  dm_ctl_ioctl+0xe/0x20 [dm_mod]
[ 4029.115447]  do_vfs_ioctl+0x8d/0x5a0
[ 4029.115459]  ? ____fput+0x9/0x10
[ 4029.115470]  ? task_work_run+0x79/0xa0
[ 4029.115481]  SyS_ioctl+0x3c/0x70
[ 4029.115493]  entry_SYSCALL_64_fastpath+0x13/0x94

The raid_preresume() function incorrectly assumes that the raid_set has
a bitmap enabled if RT_FLAG_RS_BITMAP_LOADED is set.  But
RT_FLAG_RS_BITMAP_LOADED is getting set in __load_dirty_region_bitmap()
even if there is no bitmap present (and bitmap_load() happily returns 0
even if a bitmap isn't present).  So the only way forward in the
near-term is to check if the bitmap is present by seeing if
mddev->bitmap is not NULL after bitmap_load() has been called.

By doing so the above NULL pointer is avoided.

Fixes: 4257e08 ("dm raid: support to change bitmap region size")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Dmitry Bilunov 
Signed-off-by: Andrey Smetanin 
Acked-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm raid: add raid4/5/6 journal write-back support via journal_mode option

2017-03-27T16:08:07+00:00

Commit 63c32ed4afc ("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 
Signed-off-by: Mike Snitzer

dm raid: fix table line argument order in status

2017-03-27T15:45:26+00:00

Commit 3a1c1ef2f ("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: 3a1c1ef2f ("dm raid: enhance status interface and fixup takeover/raid0")
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm raid: bump the target version

2017-02-28T21:47:52+00:00

This version bump reflects that the reshape corruption fix (commit
92a39f6cc "dm raid: fix data corruption on reshape request") is
present.

Done as a separate fix because the above referenced commit is marked for
stable and target version bumps in a stable@ fix are a recipe for the
fix to never get backported to stable@ kernels (because of target
version number conflicts).

Also, move RESUME_STAY_FROZEN_FLAGS up with the reset the the _FLAGS
definitions now that we don't need to worry about stable@ conflicts as a
result of missing context.

Signed-off-by: Mike Snitzer

dm raid: fix data corruption on reshape request

2017-02-28T21:47:51+00:00

The lvm2 sequence to manage dm-raid constructor flags that trigger a
rebuild or a reshape is defined as:

1) load table with flags (e.g. rebuild/delta_disks/data_offset)
2) clear out the flags in lvm2 metadata
3) store the lvm2 metadata, reload the table to reset the flags
   previously established during the initial load (1) -- in order to
   prevent repeatedly requesting a rebuild or a reshape on activation

Currently, loading an inactive table with rebuild/reshape flags
specified will cause dm-raid to rebuild/reshape on resume and thus start
updating the raid metadata (about the progress).  When the second table
reload, to reset the flags, occurs the constructor accesses the volatile
progress state kept in the raid superblocks.  Because the active mapping
is still processing the rebuild/reshape, that position will be stale by
the time the device is resumed.

In the reshape case, this causes data corruption by processing already
reshaped stripes again.  In the rebuild case, it does _not_ cause data
corruption but instead involves superfluous rebuilds.

Fix by keeping the raid set frozen during the first resume and then
allow the rebuild/reshape during the second resume.

Fixes: 9dbd1aa3a ("dm raid: add reshaping support to the target")
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org # 4.8+

dm raid: fix raid "check" regression due to improper cleanup in raid_message()

2017-02-28T21:47:50+00:00

While cleaning up awkward branching in raid_message() a raid set "check"
regression was introduced because "check" needs both MD_RECOVERY_SYNC
and MD_RECOVERY_REQUESTED flags set.

Fix this regression by explicitly setting both flags for the "check"
case (like is also done for the "repair" case, but redundant set_bit()s
are perfectly fine because it adds clarity to what is needed in response
to both messages -- in addition this isn't fast path code).

Fixes: 105db59912 ("dm raid: cleanup awkward branching in raid_message() option processing")
Reported-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer