Commit Graph

3988 Commits

Author SHA1 Message Date
Mike Snitzer
0fcb04d593 dm thin: fix regression in advertised discard limits
When establishing a thin device's discard limits we cannot rely on the
underlying thin-pool device's discard capabilities (which are inherited
from the thin-pool's underlying data device) given that DM thin devices
must provide discard support even when the thin-pool's underlying data
device doesn't support discards.

Users were exposed to this thin device discard limits regression if
their thin-pool's underlying data device does _not_ support discards.
This regression caused all upper-layers that called the
blkdev_issue_discard() interface to not be able to issue discards to
thin devices (because discard_granularity was 0).  This regression
wasn't caught earlier because the device-mapper-test-suite's extensive
'thin-provisioning' discard tests are only ever performed against
thin-pool's with data devices that support discards.

Fix is to have thin_io_hints() test the pool's 'discard_enabled' feature
rather than inferring whether or not a thin device's discard support
should be enabled by looking at the thin-pool's discard_granularity.

Fixes: 216076705 ("dm thin: disable discard support for thin devices if pool's is disabled")
Reported-by: Mike Gerber <mike@sprachgewalt.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.1+
2015-11-23 14:54:46 -05:00
Mikulas Patocka
bcbd94ff48 dm crypt: fix a possible hang due to race condition on exit
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: dc2676210c ("dm crypt: offload writes to thread")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-19 13:38:30 -05:00
Junichi Nomura
43e43c9ea6 dm mpath: fix infinite recursion in ioctl when no paths and !queue_if_no_path
In multipath_prepare_ioctl(),
  - pgpath is a path selected from available paths
  - m->queue_io is true if we cannot send a request immediately to
    paths, either because:
      * there is no available path
      * the path group needs activation (pg_init)
          - pg_init is not started
          - pg_init is still running
  - m->queue_if_no_path is true if the device is configured to queue
    I/O if there are no available paths

If !pgpath && !m->queue_if_no_path, the handler should return -EIO.
However in the course of refactoring the condition check has broken
and returns success in that case.  Since bdev points to the dm device
itself, dm_blk_ioctl() calls __blk_dev_driver_ioctl() for itself and
recurses until crash.

You could reproduce the problem like this:

  # dmsetup create mp --table '0 1024 multipath 0 0 0 0'
  # sg_inq /dev/mapper/mp
  <crash>
  [  172.648615] BUG: unable to handle kernel paging request at fffffffc81b10268
  [  172.662843] PGD 19dd067 PUD 0
  [  172.666269] Thread overran stack, or stack corrupted
  [  172.671808] Oops: 0000 [#1] SMP
  ...

Fix the condition check with some clarifications.

Fixes: e56f81e0b0 ("dm: refactor ioctl handling")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-17 14:19:00 -05:00
Mike Snitzer
647a20d5ca dm: do not reuse dm_blk_ioctl block_device input as local variable
(Ab)using the @bdev passed to dm_blk_ioctl() opens the potential for
targets' .prepare_ioctl to fail if they go on to check the bdev for
!NULL.

Fixes: e56f81e0b0 ("dm: refactor ioctl handling")
Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-17 14:18:49 -05:00
Junichi Nomura
5bbbfdf685 dm: fix ioctl retry termination with signal
dm-mpath retries ioctl, when no path is readily available and the device
is configured to queue I/O in such a case. If you want to stop the retry
before multipathd decides to turn off queueing mode, you could send
signal for the process to exit from the loop.

However the check of fatal signal has not carried along when commit
6c182cd88d ("dm mpath: fix ioctl deadlock when no paths") moved the
loop from dm-mpath to dm core. As a result, we can't terminate such
a process in the retry loop.

Easy reproducer of the situation is:

  # dmsetup create mp --table '0 1024 multipath 0 0 0 0'
  # dmsetup message mp 0 'queue_if_no_path'
  # sg_inq /dev/mapper/mp

then you should be able to terminate sg_inq by pressing Ctrl+C.

Fixes: 6c182cd88d ("dm mpath: fix ioctl deadlock when no paths")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2015-11-17 14:04:32 -05:00
Mike Snitzer
172c238612 dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition
A thin-pool that is in out-of-data-space (OODS) mode may transition back
to write mode -- without the admin adding more space to the thin-pool --
if/when blocks are released (either by deleting thin devices or
discarding provisioned blocks).

But as part of the thin-pool's earlier transition to out-of-data-space
mode the thin-pool may have set the 'error_if_no_space' flag to true if
the no_space_timeout expires without more space having been made
available.  That implementation detail, of changing the pool's
error_if_no_space setting, needs to be reset back to the default that
the user specified when the thin-pool's table was loaded.

Otherwise we'll drop the user requested behaviour on the floor when this
out-of-data-space to write mode transition occurs.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Fixes: 2c43fd26e4 ("dm thin: fix missing out-of-data-space to write mode transition if blocks are released")
Cc: stable@vger.kernel.org
2015-11-16 09:36:08 -05:00
Linus Torvalds
3419b45039 Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block
Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

  Currently O_DIRECT sync read/write are supported.  A framework is in
  the works that allows scalable stats tracking so we can auto-tune
  this.  And we'll add libaio support as well soon.  Fow now, it's an
  opt-in feature for test purposes"

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio->bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change ->make_request_fn() and users to return a queue cookie
2015-11-10 17:23:49 -08:00
Linus Torvalds
3934bbc044 config fix for md
config dependency needed as md/raid5 now uses crc32c
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJWP8lRAAoJEDnsnt1WYoG5AQ0P/REvKfJxP870gS6p5gowMYXN
 1pwOdq9t2MeVkQk0Q5xBOZFGQI2TL2VZjaZdiSEKqaHgd3IOD/aGpl2exLN8nZM4
 mNx+iD3QvEpmSA9mwlCe+V8vTuE0JeTpod9pXk+aQ0DIUx60dSmWh0Lp8ctr33oQ
 inlJ7kXFws6rG0xU0pOaSDM1hI0sC06Nyi2tvRSyZlZbBIMjZWorzJFUQuVX43rD
 7cQJSQ8z2e2x3V7KXYtZf6Kxe+NzEltnq0OAfnDvjz3iw+a9qU6Qg7diAbcwOdyP
 m34/MHJGIYX9GBlTtVo3+j+h3ppaPpLfT4emeYUPTQCkMXg7J9Zbjkwso7OSkvnL
 kovtgIWRVzxFx/k7jhoWzNOsacOhTFz0E4aKDpOeH2cfU7k5H/siIjeIYcqfW3fU
 q8fJXMplHz3XRYp0JhR5DRJZSw87eQnkIRkvSy8wHx8KVoRi7KNm7fv/3Zi7FpaU
 XnbxQa6FrIoqbqeBQ666Rlkn+r2Ftmj50eudAhbj4/PBesRmt6otvr9uCK+b+adh
 ZI748BC2/IOOK34WNktRQCyS2C4b3VLwRVMHReD1xir34rGGcKO04Hci8T7Qb0nP
 uJBAxmE2zue0oE6d+nnrJS3BlEC2ZFKJGzRxKiLCU7nXXoGCznd++IIPRHAkGhZc
 MSMpaS2mqtdTNp4n+9y8
 =dN6h
 -----END PGP SIGNATURE-----

Merge tag 'md/4.4-rc0-fix' of git://neil.brown.name/md

Pull config fix for md from Neil Brown:
 "New config dependency needed as md/raid5 now uses crc32c"

* tag 'md/4.4-rc0-fix' of git://neil.brown.name/md:
  raid5-cache: add crc32c Kconfig dependency
2015-11-10 12:13:00 -08:00
Arnd Bergmann
14f09e2f9b raid5-cache: add crc32c Kconfig dependency
The recent change of the raid5-cache code to use crc32c instead
of crc32 causes link errors when CONFIG_LIBCRC32C is disabled:

drivers/built-in.o: In function crc32c'
core.c:(.text+0x1c6060): undefined reference to `crc32c'

This adds an explicit 'select' statement like all other users
of this function do.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 5cb2fbd6ea ("raid5-cache: use crc32c checksum")
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-09 09:09:52 +11:00
Linus Torvalds
ad804a0b2a Merge branch 'akpm' (patches from Andrew)
Merge second patch-bomb from Andrew Morton:

 - most of the rest of MM

 - procfs

 - lib/ updates

 - printk updates

 - bitops infrastructure tweaks

 - checkpatch updates

 - nilfs2 update

 - signals

 - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
   dma-debug, dma-mapping, ...

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits)
  ipc,msg: drop dst nil validation in copy_msg
  include/linux/zutil.h: fix usage example of zlib_adler32()
  panic: release stale console lock to always get the logbuf printed out
  dma-debug: check nents in dma_sync_sg*
  dma-mapping: tidy up dma_parms default handling
  pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
  kexec: use file name as the output message prefix
  fs, seqfile: always allow oom killer
  seq_file: reuse string_escape_str()
  fs/seq_file: use seq_* helpers in seq_hex_dump()
  coredump: change zap_threads() and zap_process() to use for_each_thread()
  coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
  signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT)
  signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
  signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
  signals: kill block_all_signals() and unblock_all_signals()
  nilfs2: fix gcc uninitialized-variable warnings in powerpc build
  nilfs2: fix gcc unused-but-set-variable warnings
  MAINTAINERS: nilfs2: add header file for tracing
  nilfs2: add tracepoints for analyzing reading and writing metadata files
  ...
2015-11-07 14:32:45 -08:00
Linus Torvalds
75021d2859 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial updates from Jiri Kosina:
 "Trivial stuff from trivial tree that can be trivially summed up as:

   - treewide drop of spurious unlikely() before IS_ERR() from Viresh
     Kumar

   - cosmetic fixes (that don't really affect basic functionality of the
     driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek

   - various comment / printk fixes and updates all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  bcache: Really show state of work pending bit
  hwmon: applesmc: fix comment typos
  Kconfig: remove comment about scsi_wait_scan module
  class_find_device: fix reference to argument "match"
  debugfs: document that debugfs_remove*() accepts NULL and error values
  net: Drop unlikely before IS_ERR(_OR_NULL)
  mm: Drop unlikely before IS_ERR(_OR_NULL)
  fs: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: net: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: misc: Drop unlikely before IS_ERR(_OR_NULL)
  UBI: Update comments to reflect UBI_METAONLY flag
  pktcdvd: drop null test before destroy functions
2015-11-07 13:05:44 -08:00
Jens Axboe
dece16353e block: change ->make_request_fn() and users to return a queue cookie
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-07 10:40:46 -07:00
Mel Gorman
d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__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 <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Petr Mladek
8d090f4731 bcache: Really show state of work pending bit
WORK_STRUCT_PENDING is a mask for testing the pending bit.
test_bit() expects the number of the bit and we need to
use WORK_STRUCT_PENDING_BIT there.

Also work_data_bits() is defined in workqueues.h now.

I have noticed this just by chance when looking how
WORK_STRUCT_PENDING_BIT is used. The change is compile
tested.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-11-06 15:06:05 +01:00
Linus Torvalds
e0700ce709 - Revert a dm-multipath change that caused a regression for unprivledged
users (e.g. kvm guests) that issued ioctls when a multipath device had
   no available paths.
 
 - Include Christoph's refactoring of DM's ioctl handling and add support
   for passing through persistent reservations with DM multipath.
 
 - All other changes are very simple cleanups.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJWOp04AAoJEMUj8QotnQNaFLsH/AhMEH/jI1ObOfy4J1Wy4rOx
 ujJT91uS/s0H3pc9cGKQYnuGpFkX6WWU4wMiabIyiTn4sAsoXaflfIGutivLiDJr
 HfecrMrGZgnP4ZlpPPB02BmlxFbcPW8yzAU4ma38xBgQ+Pu30RO/HkvX/2vKOppG
 qwPop/XsNxq3KXgFGM44ToytM6c/MPGluhuvOwbaacAO1HviMuen9qsVjk4kwcf3
 jGYTbEPHATxyu5/6oKDTkQTYhzdwg3B2qHCiKMGw3l1kXhaQLFcaOivOLV8Sf3xh
 bj1070pkGe9OpqaVzMnwDtJ8rnsBl/Nt4wj9oiQPxbX71GYZAmcMIYn9WEkcKFI=
 =AR2D
 -----END PGP SIGNATURE-----

Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:
 "Smaller set of DM changes for this merge.  I've based these changes on
  Jens' for-4.4/reservations branch because the associated DM changes
  required it.

   - Revert a dm-multipath change that caused a regression for
     unprivledged users (e.g. kvm guests) that issued ioctls when a
     multipath device had no available paths.

   - Include Christoph's refactoring of DM's ioctl handling and add
     support for passing through persistent reservations with DM
     multipath.

   - All other changes are very simple cleanups"

* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm switch: simplify conditional in alloc_region_table()
  dm delay: document that offsets are specified in sectors
  dm delay: capitalize the start of an delay_ctr() error message
  dm delay: Use DM_MAPIO macros instead of open-coded equivalents
  dm linear: remove redundant target name from error messages
  dm persistent data: eliminate unnecessary return values
  dm: eliminate unused "bioset" process for each bio-based DM device
  dm: convert ffs to __ffs
  dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
  dm: add support for passing through persistent reservations
  dm: refactor ioctl handling
  Revert "dm mpath: fix stalls when handling invalid ioctls"
  dm: initialize non-blk-mq queue data before queue is used
2015-11-04 21:19:53 -08:00
Linus Torvalds
ac322de6bf md updates for 4.4.
Two major components to this update.
 
 1/ the clustered-raid1 support from SUSE is nearly
   complete.  There are a few outstanding issues being
   worked on.  Maybe half a dozen patches will bring
   this to a usable state.
 
 2/ The first stage of journalled-raid5 support from
    Facebook makes an appearance.  With a journal
    device configured (typically NVRAM or SSD), the
    "RAID5 write hole" should be closed - a crash
    during degraded operations cannot result in data
    corruption.
 
    The next stage will be to use the journal as a
    write-behind cache so that latency can be reduced
    and in some cases throughput increased by
    performing more full-stripe writes.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJWNX9RAAoJEDnsnt1WYoG5bYMP/jI0pV3wcbs7mZQAa8S/V0lU
 2l25x4MdwDvqVKMfjIc/C5J08QNgcrgSvhiVPCEOK0w18q395vep9f6gFKbMHhu/
 lWU3PLHGw8XBHp5yEnxrpQkN0pRrNjh5NqIdlVMBNyL6u+RZPS2ZuzxJ8wiNAFg1
 MypNkgoUu6s+nBp4DWWnMGYhBc+szBR+gTYAzGiZ8vqOH9uiSJ2SsGG5aRVUN/af
 oMYvJAf9aA6uj+xSzNlXIaLfWJIrshQYS1jU/W4gTm0DwK9yqbTxvubJaE0SGu/o
 73FGU8tmQ6ELYfsp3D/jmfUkE7weiNEQhdVb/4wy1A/SGc+W7Ju9pxfhm8ra57s0
 /BCkfwWZXEvx1flegXfK1mC6EMpMIcGAD2FQEhmQbW6wTdDwtNyEhIePDVGJwD/F
 rhEThFa+Dg9+xnBGnS6OUK3EpXgml2hAeAC7uA3TVSAnWd/9/Mpim6fZhqrB/v9L
 Ik0tZt+H4nxYaheZjKlKhuXUQYcUWGiMb67bGMem/YAlMa4y9C9qF+9mPXxyjVlI
 hBsd5SfZNz99DyB/bO8BumQeIWlTfzLeFzWW67eQ864LRKO6k0/VIbPZHCfn2oVG
 XvyC2fUhNOIURP3IMxcyHYxOA7Mu6EDsVVDTpuqLVbZQ5IPjDEfQ54yB/BLUvbX/
 Gh2/tKn7Xc25HuLAFEbs
 =TD5o
 -----END PGP SIGNATURE-----

Merge tag 'md/4.4' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Two major components to this update.

   1) The clustered-raid1 support from SUSE is nearly complete.  There
      are a few outstanding issues being worked on.  Maybe half a dozen
      patches will bring this to a usable state.

   2) The first stage of journalled-raid5 support from Facebook makes an
      appearance.  With a journal device configured (typically NVRAM or
      SSD), the "RAID5 write hole" should be closed - a crash during
      degraded operations cannot result in data corruption.

      The next stage will be to use the journal as a write-behind cache
      so that latency can be reduced and in some cases throughput
      increased by performing more full-stripe writes.

* tag 'md/4.4' of git://neil.brown.name/md: (66 commits)
  MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RW
  MD: set journal disk ->raid_disk
  MD: kick out journal disk if it's not fresh
  raid5-cache: start raid5 readonly if journal is missing
  MD: add new bit to indicate raid array with journal
  raid5-cache: IO error handling
  raid5: journal disk can't be removed
  raid5-cache: add trim support for log
  MD: fix info output for journal disk
  raid5-cache: use bio chaining
  raid5-cache: small log->seq cleanup
  raid5-cache: new helper: r5_reserve_log_entry
  raid5-cache: inline r5l_alloc_io_unit into r5l_new_meta
  raid5-cache: take rdev->data_offset into account early on
  raid5-cache: refactor bio allocation
  raid5-cache: clean up r5l_get_meta
  raid5-cache: simplify state machine when caches flushes are not needed
  raid5-cache: factor out a helper to run all stripes for an I/O unit
  raid5-cache: rename flushed_ios to finished_ios
  raid5-cache: free I/O units earlier
  ...
2015-11-04 21:12:47 -08:00
Linus Torvalds
527d1529e3 Merge branch 'for-4.4/integrity' of git://git.kernel.dk/linux-block
Pull block integrity updates from Jens Axboe:
 ""This is the joint work of Dan and Martin, cleaning up and improving
  the support for block data integrity"

* 'for-4.4/integrity' of git://git.kernel.dk/linux-block:
  block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
  block: blk_flush_integrity() for bio-based drivers
  block: move blk_integrity to request_queue
  block: generic request_queue reference counting
  nvme: suspend i/o during runtime blk_integrity_unregister
  md: suspend i/o during runtime blk_integrity_unregister
  md, dm, scsi, nvme, libnvdimm: drop blk_integrity_unregister() at shutdown
  block: Inline blk_integrity in struct gendisk
  block: Export integrity data interval size in sysfs
  block: Reduce the size of struct blk_integrity
  block: Consolidate static integrity profile properties
  block: Move integrity kobject to struct gendisk
2015-11-04 20:51:48 -08:00
Linus Torvalds
af7eba0158 two more bug fixes for md.
One bugfix for a list corruption in raid5 because of incorrect
 locking.
 
 Other for possible data corruption when a recovering device is failed,
 removed, and re-added.
 
 Both tagged for -stable.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJWNAnCAAoJEDnsnt1WYoG5VzwP/jRfljaxLKUicIGEd9qeaei5
 vVtmzPugthzYTfcJRm54ZufQOnjse/uXEBqmvoMJhBeEMbL2VIWbn1i7sMWjgq8W
 HVz/N/N8iT5DFWgzXmQQCaxIu17njbEmO8IelcNr3i6tE5wbHJ9WhV5UDGdQgwca
 6XjQ8r8QjmN3uVaiNL4JcrEtZfpE8PqgBCJzsQYRZzOp9m3jJlgyJ9YWQA/VQ2Cj
 cVXs7tTGTdpPQdgRRFHF/Z/7H+KUcp9XV5ahDRwqDryQkZHuFvwyZFfpLspqvc5P
 OJio9WY0y93QmRRsuIC/ig0+CnxDXeqHiRwbprIMvKbPxxaGn4s24VioRDa0PRzT
 v9HcjtUhs9q8iTo4TZJrggD+rPm523a9iiDU6SbM2qlM3XUpBis/fjbLN82Nnas+
 ADa0/DAsOE0I1WltoaaNUbweuflGw2NnFxnUueqq8dK23/Vabu3vw4tohiNp+/3m
 km8Is3j7lGKobQ3AKYIFlbeAqdsyASZkSDfA9IZr3SIeYBWgPljd9n+6BIPOqPNq
 S2HtOLke/XX2KEM0BHzgu4XliE9P9+B9lQETI4MehP0rMzTURGKh87du41YHckp1
 beX22aeOuv//ok11JTs6M+StREKeTrl+dTStn0U1jt6HyMzseGaNoy3Eib5ePBCb
 C2ZZRz4OR2MWvWUFxKms
 =QYvv
 -----END PGP SIGNATURE-----

Merge tag 'md/4.3-rc7-fixes' of git://neil.brown.name/md

Pull md bug fixes from Neil Brown:
 "Two more bug fixes for md.

  One bugfix for a list corruption in raid5 because of incorrect
  locking.

  Other for possible data corruption when a recovering device is failed,
  removed, and re-added.

  Both tagged for -stable"

* tag 'md/4.3-rc7-fixes' of git://neil.brown.name/md:
  Revert "md: allow a partially recovered device to be hot-added to an array."
  md/raid5: fix locking in handle_stripe_clean_event()
2015-10-31 21:20:49 -07:00
Song Liu
339421def5 MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RW
When RAID-4/5/6 array suffers from missing journal device, we put
the array in read only state. We should not allow trasition to
read-write states (clean and active) before replacing journal device.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
f2076e7d06 MD: set journal disk ->raid_disk
Set journal disk ->raid_disk to >=0, I choose raid_disks + 1 instead of
0, because we already have a disk with ->raid_disk 0 and this causes
sysfs entry creation conflict. A lot of places assumes disk with
->raid_disk >=0 is normal raid disk, so we add check for journal disk.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Song Liu
a3dfbdaadb MD: kick out journal disk if it's not fresh
When journal disk is faulty and we are reassemabling the raid array, the
journal disk is old. We don't allow the journal disk added to the raid
array. Since journal disk is missing in the array, the raid5 will mark
the array readonly.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
7dde2ad3c5 raid5-cache: start raid5 readonly if journal is missing
If raid array is expected to have journal (eg, journal is set in MD
superblock feature map) and the array is started without journal disk,
start the array readonly.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Song Liu
a97b789644 MD: add new bit to indicate raid array with journal
If a raid array has journal feature bit set, add a new bit to indicate
this. If the array is started without journal disk existing, we know
there is something wrong.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
6e74a9cfb5 raid5-cache: IO error handling
There are 3 places the raid5-cache dispatches IO. The discard IO error
doesn't matter, so we ignore it. The superblock write IO error can be
handled in MD core. The remaining are log write and flush. When the IO
error happens, we mark log disk faulty and fail all write IO. Read IO is
still allowed to run. Userspace will get a notification too and
corresponding daemon can choose setting raid array readonly for example.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
c2bb6242ec raid5: journal disk can't be removed
raid5-cache uses journal disk rdev->bdev, rdev->mddev in several places.
Don't allow journal disk disappear magically. On the other hand, we do
need to update superblock for other disks to bump up ->events, so next
time journal disk will be identified as stale.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
4b482044d2 raid5-cache: add trim support for log
Since superblock is updated infrequently, we do a simple trim of log
disk (a synchronous trim)

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Shaohua Li
9efdca16e0 MD: fix info output for journal disk
journal disk can be faulty. The Journal and Faulty aren't exclusive with
each other.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:29 +11:00
Christoph Hellwig
6143e2cecb raid5-cache: use bio chaining
Simplify the bio completion handler by using bio chaining and submitting
bios as soon as they are full.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
2b8ef16ec4 raid5-cache: small log->seq cleanup
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
c1b9919849 raid5-cache: new helper: r5_reserve_log_entry
Factor out code to reserve log space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
51039cd066 raid5-cache: inline r5l_alloc_io_unit into r5l_new_meta
This is the only user, and keeping all code initializing the io_unit
structure together improves readbility.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
1e932a37cc raid5-cache: take rdev->data_offset into account early on
Set up bi_sector properly when we allocate an bio instead of updating it
at submission time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
b349feb36c raid5-cache: refactor bio allocation
Split out a helper to allocate a bio for log writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
22581f58ed raid5-cache: clean up r5l_get_meta
Remove the only partially used local 'io' variable to simplify the code
flow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
56fef7c6e0 raid5-cache: simplify state machine when caches flushes are not needed
For devices without a volatile write cache we don't need to send a FLUSH
command to ensure writes are stable on disk, and thus can avoid the whole
step of batching up bios for processing by the MD thread.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:28 +11:00
Christoph Hellwig
d8858f4321 raid5-cache: factor out a helper to run all stripes for an I/O unit
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Christoph Hellwig
04732f741d raid5-cache: rename flushed_ios to finished_ios
After this series we won't nessecarily have flushed the cache for these
I/Os, so give the list a more neutral name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Christoph Hellwig
170364619a raid5-cache: free I/O units earlier
There is no good reason to keep the I/O unit structures around after the
stripe has been written back to the RAID array.  The only information
we need is the log sequence number, and the checkpoint offset of the
highest successfull writeback.  Store those in the log structure, and
free the IO units from __r5l_stripe_write_finished.

Besides simplifying the code this also avoid having to keep the allocation
for the I/O unit around for a potentially long time as superblock updates
that checkpoint the log do not happen very often.

This also fixes the previously incorrect calculation of 'free' in
r5l_do_reclaim as a side effect: previous if took the last unit which
isn't checkpointed into account.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Shaohua Li
e6c033f79a raid5-cache: move reclaim stop to quiesce
Move reclaim stop to quiesce handling, where is safer for this stuff.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Shaohua Li
ac6096e9d5 md: show journal for journal disk in disk state sysfs
Journal disk state sysfs entry should indicate it's journal

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Song Liu
0b020e85bd skip match_mddev_units check for special roles
match_mddev_units is used to check whether 2 RAID arrays share
same disk(s). Arrays that share disk(s) will not do resync at the
same time for better performance (fewer HDD seek). However, this
check should not apply to Spare, Faulty, and Journal disks, as
they do not paticipate in resync.

In this patch, match_mddev_units skips check for disks with flag
"Faulty" or "Journal" or raid_disk < 0.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Shaohua Li
253f9fd41a raid5-cache: don't delay stripe captured in log
There is a case a stripe gets delayed forever.
1. a stripe finishes construction
2. a new bio hits the stripe
3. handle_stripe runs for the stripe. The stripe gets DELAYED bit set
since construction can't run for new bio (the stripe is locked since
step 1)

Without log, handle_stripe will call ops_run_io. After IO finishes, the
stripe gets unlocked and the stripe will restart and run construction
for the new bio. With log, ops_run_io need to run two times. If the
DELAYED bit set, the stripe can't enter into the handle_list, so the
second ops_run_io doesn't run, which leaves the stripe stalled.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:27 +11:00
Shaohua Li
85f2f9a4f4 raid5-cache: check stripe finish out of order
stripes could finish out of order. Hence r5l_move_io_unit_list() of
__r5l_stripe_write_finished might not move any entry and leave
stripe_end_ios list empty.

This applies on top of http://marc.info/?l=linux-raid&m=144122700510667

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
bd18f6462f md: skip resync for raid array with journal
If a raid array has journal, the journal can guarantee the consistency,
we can skip resync after a unclean shutdown. The exception is raid
creation or user initiated resync, which we still do a raid resync.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
828cbe989e raid5-cache: optimize FLUSH IO with log enabled
With log enabled, bio is written to raid disks after the bio is settled
down in log disk. The recovery guarantees we can recovery the bio data
from log disk, so we we skip FLUSH IO.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Christoph Hellwig
509ffec708 raid5-cache: move functionality out of __r5l_set_io_unit_state
Just keep __r5l_set_io_unit_state as a small set the state wrapper, and
remove r5l_set_io_unit_state entirely after moving the real
functionality to the two callers that need it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
0fd22b45b2 raid5-cache: fix a user-after-free bug
r5l_compress_stripe_end_list() can free an io_unit. This breaks the
assumption only reclaimer can free io_unit. We can add a reference count
based io_unit free, but since only reclaim can wait io_unit becoming to
STRIPE_END state, we use a simple global wait queue here.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
a8c34f9159 raid5-cache: switching to state machine for log disk cache flush
Before we write stripe data to raid disks, we must guarantee stripe data
is settled down in log disk. To do this, we flush log disk cache and
wait the flush finish. That wait introduces sleep time in raid5d thread
and impact performance. This patch moves the log disk cache flush
process to the stripe handling state machine, which can remove the wait
in raid5d.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
5c7e81c3de raid5: enable log for raid array with cache disk
Now log is safe to enable for raid array with cache disk

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00
Shaohua Li
713cf5a639 raid5: don't allow resize/reshape with cache(log) support
If cache(log) support is enabled, don't allow resize/reshape in current
stage. In the future, we can flush all data from cache(log) to raid
before resize/reshape and then allow resize/reshape.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-11-01 13:48:26 +11:00