Commit Graph

3539 Commits

Author SHA1 Message Date
Linus Torvalds
88ed806abb md updates for 3.18
- a few minor bug fixes
 - quite a lot of code tidy-up and simplification
 - remove PRINT_RAID_DEBUG ioctl.  I'm fairly sure
   it is unused, and it isn't particularly useful.
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Merge tag 'md/3.18' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 - a few minor bug fixes
 - quite a lot of code tidy-up and simplification
 - remove PRINT_RAID_DEBUG ioctl.  I'm fairly sure it is unused, and it
   isn't particularly useful.

* tag 'md/3.18' of git://neil.brown.name/md: (21 commits)
  lib/raid6: Add log level to printks
  md: move EXPORT_SYMBOL to after function in md.c
  md: discard PRINT_RAID_DEBUG ioctl
  md: remove MD_BUG()
  md: clean up 'exit' labels in md_ioctl().
  md: remove unnecessary test for MD_MAJOR in md_ioctl()
  md: don't allow "-sync" to be set for device in an active array.
  md: remove unwanted white space from md.c
  md: don't start resync thread directly from md thread.
  md: Just use RCU when checking for overlap between arrays.
  md: avoid potential long delay under pers_lock
  md: simplify export_array()
  md: discard find_rdev_nr in favour of find_rdev_nr_rcu
  md: use wait_event() to simplify md_super_wait()
  md: be more relaxed about stopping an array which isn't started.
  md/raid1: process_checks doesn't use its return value.
  md/raid5: fix init_stripe() inconsistencies
  md/raid10: another memory leak due to reshape.
  md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.
  md/raid1: minor typos and reformatting.
  ...
2014-10-18 11:39:52 -07:00
Mikulas Patocka
9d28eb1244 dm bufio: change __GFP_IO to __GFP_FS in shrinker callbacks
The shrinker uses gfp flags to indicate what kind of operation can the
driver wait for. If __GFP_IO flag is present, the driver can wait for
block I/O operations, if __GFP_FS flag is present, the driver can wait on
operations involving the filesystem.

dm-bufio tested for __GFP_IO. However, dm-bufio can run on a loop block
device that makes calls into the filesystem. If __GFP_IO is present and
__GFP_FS isn't, dm-bufio could still block on filesystem operations if it
runs on a loop block device.

The change from __GFP_IO to __GFP_FS supposedly fixes one observed (though
unreproducible) deadlock involving dm-bufio and loop device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-10-17 01:40:23 -04:00
Linus Torvalds
0429fbc0bd Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
2014-10-15 07:48:18 +02:00
Jan-Simon Möller
b610626523 crypto, dm: LLVMLinux: Remove VLAIS usage from dm-crypt
Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.

Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: pageexec@freemail.hu
Cc: gmazyland@gmail.com
Cc: "David S. Miller" <davem@davemloft.net>
2014-10-14 10:51:23 +02:00
NeilBrown
6c144d3164 md: move EXPORT_SYMBOL to after function in md.c
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
2cbbca5e7c md: discard PRINT_RAID_DEBUG ioctl
All the interesting information printed by this ioctl
is provided in /proc/mdstat and/or sysfs.
So it isn't needed and isn't used and would be best if it didn't
exist.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
403df47888 md: remove MD_BUG()
Most of the places that call this are doing so pointlessly.
A couple of the others a best replaced with WARN_ON().

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
3adc28d85f md: clean up 'exit' labels in md_ioctl().
There are 4 labels and we only really need two.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
326eb17d73 md: remove unnecessary test for MD_MAJOR in md_ioctl()
unknown ioctls no longer get this deep into md_ioctl since
md_ioctl_valid() was introduced in 3.14.
So remove the test and the misleading comment.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
e1960f8c5c md: don't allow "-sync" to be set for device in an active array.
If an array is active, devices can be marked 'faulty', but simply
removing the 'sync' flag is wrong.  That only makes sense
for an array which is not active (and is probably only useful
for testing anyway).

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
f72ffdd686 md: remove unwanted white space from md.c
My editor shows much of this is RED.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:29 +11:00
NeilBrown
ac05f25669 md: don't start resync thread directly from md thread.
The main 'md' thread is needed for processing writes, so if it blocks
write requests could be delayed.

Starting a new thread requires some GFP_KERNEL allocations and so can
wait for writes to complete.  This can deadlock.

So instead, ask a workqueue to start the sync thread.
There is no particular rush for this to happen, so any work queue
will do.

MD_RECOVERY_RUNNING is used to ensure only one thread is started.

Reported-by: BillStuff <billstuff2001@sbcglobal.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
8b1afc3d67 md: Just use RCU when checking for overlap between arrays.
We don't really need the full mddev_lock here, and having to
drop it is messy.
RCU is enough to protect these lists.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
Chao Yu
50bd377405 md: avoid potential long delay under pers_lock
printk may cause long time lapse if value of printk_delay in sysctl is
configured large by user. If register_md_personality takes long time to print in
spinlock pers_lock, we may encounter high CPU usage rate when there are other
pers_lock competitors who may be blocked to spin.
We can avoid this condition by moving printk out of coverage of pers_lock
spinlock.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
0638bb0e73 md: simplify export_array()
We don't really need that for_each loop, or those MD_BUGs.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
4878e9eb88 md: discard find_rdev_nr in favour of find_rdev_nr_rcu
Having both is a waste - just use the one.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
1967cd5616 md: use wait_event() to simplify md_super_wait()
md_super_wait is really just wait_event() open-coded.
So use the macro instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
9ba3b7f5d0 md: be more relaxed about stopping an array which isn't started.
In general we don't allow an array to be stopped if it is in use.
However if the array hasn't really been started yet, then any
apparent use is an anomily, probably due to 'udev' or similar
having a look to see what is there.

This means that if something goes wrong while assembling an array
it cannot reliably be un-assembled - STOP_ARRAY could fail.
There is no value here, so change do_md_stop() to succeed
despite concurrent opens if the array has not yet been
activated.  i.e. if ->pers is NULL.

Reported-by: "Baldysiak, Pawel" <pawel.baldysiak@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
c95e6385e8 md/raid1: process_checks doesn't use its return value.
process_checks() always returns '0', so change it to 'void'.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
Markus Stockhausen
b8e6a15a1a md/raid5: fix init_stripe() inconsistencies
raid5: fix init_stripe() inconsistencies

1) remove_hash() is not necessary. We will only be called right after
   get_free_stripe(). There we have already a call to remove_hash().

2) Tracing prints out the sector of the freed stripe and not the sector
   that we want to initialize.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
c4796e215f md/raid10: another memory leak due to reshape.
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
Linus Torvalds
faafcba3b5 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
     Hansen)

   - Various sched/idle refinements for better idle handling (Nicolas
     Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)

   - sched/numa updates and optimizations (Rik van Riel)

   - sysbench speedup (Vincent Guittot)

   - capacity calculation cleanups/refactoring (Vincent Guittot)

   - Various cleanups to thread group iteration (Oleg Nesterov)

   - Double-rq-lock removal optimization and various refactorings
     (Kirill Tkhai)

   - various sched/deadline fixes

  ... and lots of other changes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
  sched/fair: Delete resched_cpu() from idle_balance()
  sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
  sched: Improve sysbench performance by fixing spurious active migration
  sched/x86: Fix up typo in topology detection
  x86, sched: Add new topology for multi-NUMA-node CPUs
  sched/rt: Use resched_curr() in task_tick_rt()
  sched: Use rq->rd in sched_setaffinity() under RCU read lock
  sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
  sched: Use dl_bw_of() under RCU read lock
  sched/fair: Remove duplicate code from can_migrate_task()
  sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
  sched: print_rq(): Don't use tasklist_lock
  sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
  sched: Fix the task-group check in tg_has_rt_tasks()
  sched/fair: Leverage the idle state info when choosing the "idlest" cpu
  sched: Let the scheduler see CPU idle states
  sched/deadline: Fix inter- exclusive cpusets migrations
  sched/deadline: Clear dl_entity params when setscheduling to different class
  sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
  ...
2014-10-13 16:23:15 +02:00
Pavitra Kumar
a3f2af2547 dm stripe: fix potential for leak in stripe_ctr error path
Fix a potential struct stripe_c leak that would occur if the
chunk_size exceeded the maximum allowed by dm_set_target_max_io_len
(UINT_MAX).  However, in practice there is no possibility of this
occuring given that chunk_size is of type uint32_t.  But it is good to
fix this to future-proof in case dm_set_target_max_io_len's
implementation were to change.

Signed-off-by: Pavitra Kumar <pavitrak@nvidia.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-10 22:05:18 -04:00
NeilBrown
3fd83717e4 md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.
Using {set,clear}_bit is more consistent than shifting and masking.

No functional change.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-09 10:07:04 +11:00
NeilBrown
5965b642ff md/raid1: minor typos and reformatting.
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-09 10:07:04 +11:00
NeilBrown
4b5060ddae md/bitmap: always wait for writes on unplug.
If two threads call bitmap_unplug at the same time, then
one might schedule all the writes, and the other might
decide that it doesn't need to wait.  But really it does.

It rarely hurts to wait when it isn't absolutely necessary,
and the current code doesn't really focus on 'absolutely necessary'
anyway.  So just wait always.

This can potentially lead to data corruption if a crash happens
at an awkward time and data was written before the bitmap was
updated.  It is very unlikely, but this should go to -stable
just to be safe.  Appropriate for any -stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org (please delay until 3.18 is released)
2014-10-09 10:07:04 +11:00
Alexey Khoroshilov
56ec16cb1e dm log userspace: fix memory leak in dm_ulog_tfr_init failure path
If cn_add_callback() fails in dm_ulog_tfr_init(), it does not
deallocate prealloced memory but calls cn_del_callback().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-10-05 20:03:38 -04:00
Mikulas Patocka
0e825862f3 dm bufio: when done scanning return from __scan immediately
When __scan frees the required number of buffer entries that the
shrinker requested (nr_to_scan becomes zero) it must return.  Before
this fix the __scan code exited only the inner loop and continued in the
outer loop -- which could result in reduced performance due to extra
buffers being freed (e.g. unnecessarily evicted thinp metadata needing
to be synchronously re-read into bufio's cache).

Also, move dm_bufio_cond_resched to __scan's inner loop, so that
iterating the bufio client's lru lists doesn't result in scheduling
latency.

Reported-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.2+
2014-10-05 20:03:37 -04:00
Joe Thornber
eb76faf53b dm bufio: update last_accessed when relinking a buffer
The 'last_accessed' member of the dm_buffer structure was only set when
the the buffer was created.  This led to each buffer being discarded
after dm_bufio_max_age time even if it was used recently.  In practice
this resulted in all thinp metadata being evicted soon after being read
-- this is particularly problematic for metadata intensive workloads
like multithreaded small random IO.

'last_accessed' is now updated each time the buffer is moved to the head
of the LRU list, so the buffer is now properly discarded if it was not
used in dm_bufio_max_age time.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.2+
2014-10-05 20:03:37 -04:00
Heinz Mauelshagen
48cf06bc5f dm raid: add discard support for RAID levels 4, 5 and 6
In case of RAID levels 4, 5 and 6 we have to verify each RAID members'
ability to zero data on discards to avoid stripe data corruption -- if
discard_zeroes_data is not set for each RAID member discard support must
be disabled.  But given the uncertainty of whether or not a RAID member
properly supports zeroing data on discard we require the user to
explicitly allow discard support on RAID levels 4, 5, and 6 by setting
a dm-raid module paramter, e.g.: dm-raid.devices_handle_discard_safely=Y
Otherwise, discards could cause data corruption on RAID4/5/6.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:36 -04:00
Heinz Mauelshagen
75b8e04bbf dm raid: add discard support for RAID levels 1 and 10
Discard support is not enabled for RAID levels 4, 5, and 6 at this time
due to concerns about unreliable discard_zeroes_data support on some
hardware.  Otherwise, discards could cause stripe data corruption
(classic example of bad apples spoiling the bunch).

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:36 -04:00
Benjamin Marzinski
86f1152b11 dm: allow active and inactive tables to share dm_devs
Until this change, when loading a new DM table, DM core would re-open
all of the devices in the DM table.  Now, DM core will avoid redundant
device opens (and closes when destroying the old table) if the old
table already has a device open using the same mode.  This is achieved
by managing reference counts on the table_devices that DM core now
stores in the mapped_device structure (rather than in the dm_table
structure).  So a mapped_device's active and inactive dm_tables' dm_dev
lists now just point to the dm_devs stored in the mapped_device's
table_devices list.

This improvement in DM core's device reference counting has the
side-effect of fixing a long-standing limitation of the multipath
target: a DM multipath table couldn't include any paths that were unusable
(failed).  For example: if all paths have failed and you add a new,
working, path to the table; you can't use it since the table load would
fail due to it still containing failed paths.  Now a re-load of a
multipath table can include failed devices and when those devices become
active again they can be used instantly.

The device list code in dm.c isn't a straight copy/paste from the code in
dm-table.c, but it's very close (aside from some variable renames).  One
subtle difference is that find_table_device for the tables_devices list
will only match devices with the same name and mode.  This is because we
don't want to upgrade a device's mode in the active table when an
inactive table is loaded.

Access to the mapped_device structure's tables_devices list requires a
mutex (tables_devices_lock), so that tables cannot be created and
destroyed concurrently.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:35 -04:00
Benjamin Marzinski
1f27197247 dm mpath: stop queueing IO when no valid paths exist
'queue_io' is set so that IO is queued while paths are being
initialized.  Clear queue_io in __choose_pgpath if there are no valid
paths, since there are obviously no paths that can be initialized.
Otherwise IOs to the device will back up.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:35 -04:00
Junichi Nomura
3d8aab2d2c dm: use bioset_create_nobvec()
Since DM core uses bio_clone_fast() for both bio-based and request-based
DM devices there is no need for DM's bioset to have a bvec mempool.

With this patch, on arch with 4KB page for example, memory usage will be
reduced by 64KB for each bio-based DM device and 1MB for each
request-based DM device.

For example, when you create 10,000 bio-based DM devices and 1,000
request-based DM devices, memory usage of biovec under no load is:
  # grep biovec /proc/slabinfo

  biovec-256        418068 418068   4096  ...
  biovec-128             0      0   2048  ...
  biovec-64              0      0   1024  ...
  biovec-16              0      0    256  ...

With this patch series applied, the usage becomes:
  # grep biovec /proc/slabinfo

  biovec-256           116    116   4096  ...
  biovec-128             0      0   2048  ...
  biovec-64              0      0   1024  ...
  biovec-16              0      0    256  ...

So 4096 * (418068 - 116) = 1.6GB of memory is saved in this example.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:34 -04:00
Junichi Nomura
997782735c dm: remove nr_iovecs parameter from alloc_tio()
alloc_tio() uses bio_alloc_bioset() to allocate a clone-bio for a bio.
alloc_tio() takes the number of bvecs to allocate for the clone-bio.
However, with v3.14's immutable biovec changes DM now uses
__bio_clone_fast() and no longer needs to allocate bvecs.

In practice, the 'nr_iovecs' passed to alloc_tio() is always effectively
0.  __clone_and_map_simple_bio() looked like it was passing non-zero
nr_iovecs, but its value was always within the range of inline bvecs and
no allocation actually happened.  If allocation happened, the BUG_ON() in
__bio_clone_fast() would've triggered.

Remove the nr_iovecs parameter from alloc_tio() to prevent possible
future bio_alloc_bioset() mis-use of a new bioset interface that will no
longer allow bvecs to be allocated.

Also fix extra whitespace before the __bio_clone_fast() call in
__clone_and_map_simple_bio().

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:34 -04:00
Mike Snitzer
b277da0a8a block: disable entropy contributions for nonrot devices
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.

Historically, all block devices have automatically made entropy
contributions.  But as previously stated in commit e2e1a148 ("block: add
sysfs knob for turning off disk entropy contributions"):
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    - Calling add_disk_randomness() has a lot of overhead.

There are more reliable sources for randomness than non-rotational block
devices.  From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-04 10:55:32 -06:00
NeilBrown
8e0e99ba64 md/raid5: disable 'DISCARD' by default due to safety concerns.
It has come to my attention (thanks Martin) that 'discard_zeroes_data'
is only a hint.  Some devices in some cases don't do what it
says on the label.

The use of DISCARD in RAID5 depends on reads from discarded regions
being predictably zero.  If a write to a previously discarded region
performs a read-modify-write cycle it assumes that the parity block
was consistent with the data blocks.  If all were zero, this would
be the case.  If some are and some aren't this would not be the case.
This could lead to data corruption after a device failure when
data needs to be reconstructed from the parity.

As we cannot trust 'discard_zeroes_data', ignore it by default
and so disallow DISCARD on all raid4/5/6 arrays.

As many devices are trustworthy, and as there are benefits to using
DISCARD, add a module parameter to over-ride this caution and cause
DISCARD to work if discard_zeroes_data is set.

If a site want to enable DISCARD on some arrays but not on others they
should select DISCARD support at the filesystem level, and set the
raid456 module parameter.
    raid456.devices_handle_discard_safely=Y

As this is a data-safety issue, I believe this patch is suitable for
-stable.
DISCARD support for RAID456 was added in 3.7

Cc: Shaohua Li <shli@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Heinz Mauelshagen <heinzm@redhat.com>
Cc: stable@vger.kernel.org (3.7+)
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Fixes: 620125f2bf
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-02 13:45:00 +10:00
Linus Torvalds
a90e41e228 Bugfixes for md/raid1
particularly, but not only, fixing new "resync" code.
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Merge tag 'md/3.17-more-fixes' of git://git.neil.brown.name/md

Pull bugfixes for md/raid1 from Neil Brown:
 "It is amazing how much easier it is to find bugs when you know one is
  there.  Two bug reports resulted in finding 7 bugs!

  All are tagged for -stable.  Those that can't cause (rare) data
  corruption, cause lockups.

  Particularly, but not only, fixing new "resync" code"

* tag 'md/3.17-more-fixes' of git://git.neil.brown.name/md:
  md/raid1: fix_read_error should act on all non-faulty devices.
  md/raid1: count resync requests in nr_pending.
  md/raid1: update next_resync under resync_lock.
  md/raid1: Don't use next_resync to determine how far resync has progressed
  md/raid1: make sure resync waits for conflicting writes to complete.
  md/raid1: clean up request counts properly in close_sync()
  md/raid1:  be more cautious where we read-balance during resync.
  md/raid1: intialise start_next_window for READ case to avoid hang
2014-09-24 08:53:33 -07:00
NeilBrown
b8cb6b4c12 md/raid1: fix_read_error should act on all non-faulty devices.
If a devices is being recovered it is not InSync and is not Faulty.

If a read error is experienced on that device, fix_read_error()
will be called, but it ignores non-InSync devices.  So it will
neither fix the error nor fail the device.

It is incorrect that fix_read_error() ignores non-InSync devices.
It should only ignore Faulty devices.  So fix it.

This became a bug when we allowed reading from a device that was being
recovered.  It is suitable for any subsequent -stable kernel.

Fixes: da8840a747
Cc: stable@vger.kernel.org (v3.5+)
Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
34e97f1701 md/raid1: count resync requests in nr_pending.
Both normal IO and resync IO can be retried with reschedule_retry()
and so be counted into ->nr_queued, but only normal IO gets counted in
->nr_pending.

Before the recent improvement to RAID1 resync there could only
possibly have been one or the other on the queue.  When handling a
read failure it could only be normal IO.  So when handle_read_error()
called freeze_array() the fact that freeze_array only compares
->nr_queued against ->nr_pending was safe.

But now that these two types can interleave, we can have both normal
and resync IO requests queued, so we need to count them both in
nr_pending.

This error can lead to freeze_array() hanging if there is a read
error, so it is suitable for -stable.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
c2fd4c94de md/raid1: update next_resync under resync_lock.
raise_barrier() uses next_resync as part of its calculations, so it
really should be updated first, instead of afterwards.

next_resync is always used under resync_lock so update it under
resync lock to, just before it is used.  That is safest.

This could cause normal IO and resync IO to interact badly so
it suitable for -stable.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
235549605e md/raid1: Don't use next_resync to determine how far resync has progressed
next_resync is (approximately) the location for the next resync request.
However it does *not* reliably determine the earliest location
at which resync might be happening.
This is because resync requests can complete out of order, and
we only limit the number of current requests, not the distance
from the earliest pending request to the latest.

mddev->curr_resync_completed is a reliable indicator of the earliest
position at which resync could be happening.   It is updated less
frequently, but is actually reliable which is more important.

So use it to determine if a write request is before the region
being resynced and so safe from conflict.

This error can allow resync IO to interfere with normal IO which
could lead to data corruption. Hence: stable.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
2f73d3c55d md/raid1: make sure resync waits for conflicting writes to complete.
The resync/recovery process for raid1 was recently changed
so that writes could happen in parallel with resync providing
they were in different regions of the device.

There is a problem though:  While a write request will always
wait for conflicting resync to complete, a resync request
will *not* always wait for conflicting writes to complete.

Two changes are needed to fix this:

1/ raise_barrier (which waits until it is safe to do resync)
   must wait until current_window_requests is zero
2/ wait_battier (which waits at the start of a new write request)
   must update current_window_requests if the request could
   possible conflict with a concurrent resync.

As concurrent writes and resync can lead to data loss,
this patch is suitable for -stable.

Fixes: 79ef3a8aa1
Cc: stable@vger.kernel.org (v3.13+)
Cc: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
669cc7ba77 md/raid1: clean up request counts properly in close_sync()
If there are outstanding writes when close_sync is called,
the change to ->start_next_window might cause them to
decrement the wrong counter when they complete.  Fix this
by merging the two counters into the one that will be decremented.

Having an incorrect value in a counter can cause raise_barrier()
to hangs, so this is suitable for -stable.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 11:26:01 +10:00
NeilBrown
c6d119cf1b md/raid1: be more cautious where we read-balance during resync.
commit 79ef3a8aa1 made
it possible for reads to happen concurrently with resync.
This means that we need to be more careful where read_balancing
is allowed during resync - we can no longer be sure that any
resync that has already started will definitely finish.

So keep read_balancing to before recovery_cp, which is conservative
but safe.

This bug makes it possible to read from a device that doesn't
have up-to-date data, so it can cause data corruption.
So it is suitable for any kernel since 3.11.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 10:26:41 +10:00
NeilBrown
f0cc9a0571 md/raid1: intialise start_next_window for READ case to avoid hang
r1_bio->start_next_window is not initialised in the READ
case, so allow_barrier may incorrectly decrement
   conf->current_window_requests
which can cause raise_barrier() to block forever.

Fixes: 79ef3a8aa1
cc: stable@vger.kernel.org (v3.13+)
Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-09-22 10:18:03 +10:00
Kirill Tkhai
f139caf2e8 sched, cleanup, treewide: Remove set_current_state(TASK_RUNNING) after schedule()
schedule(), io_schedule() and schedule_timeout() always return
with TASK_RUNNING state set, so one more setting is unnecessary.

(All places in patch are visible good, only exception is
 kiblnd_scheduler() from:

      drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c

 Its schedule() is one line above standard 3 lines of unified diff)

No places where set_current_state() is used for mb().

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1410529254.3569.23.camel@tkhai
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Anil Belur <askb23@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: David Howells <dhowells@redhat.com>
Cc: Dmitry Eremin <dmitry.eremin@intel.com>
Cc: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Isaac Huang <he.huang@intel.com>
Cc: James E.J. Bottomley <JBottomley@parallels.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Liang Zhen <liang.zhen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masaru Nomura <massa.nomura@gmail.com>
Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Oleg Drokin <green@linuxhacker.ru>
Cc: Peng Tao <bergwolf@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Ursula Braun <ursula.braun@de.ibm.com>
Cc: Zi Shen Lim <zlim.lnx@gmail.com>
Cc: devel@driverdev.osuosl.org
Cc: dm-devel@redhat.com
Cc: dri-devel@lists.freedesktop.org
Cc: fcoe-devel@open-fcoe.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux390@de.ibm.com
Cc: linux-afs@lists.infradead.org
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-raid@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: qla2xxx-upstream@qlogic.com
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: user-mode-linux-user@lists.sourceforge.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-19 12:35:17 +02:00
Anssi Hannula
40aa978ecc dm cache: fix race causing dirty blocks to be marked as clean
When a writeback or a promotion of a block is completed, the cell of
that block is removed from the prison, the block is marked as clean, and
the clear_dirty() callback of the cache policy is called.

Unfortunately, performing those actions in this order allows an incoming
new write bio for that block to come in before clearing the dirty status
is completed and therefore possibly causing one of these two scenarios:

Scenario A:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called,
.                               but block already dirty
.                               => it does nothing
clear_dirty()                 .
- block marked clean          .
- policy clear_dirty() called .

Result: Block is marked clean even though it is actually dirty. No
writeback will occur.

Scenario B:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
clear_dirty()                 .
- block marked clean          .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called
.                             - block marked dirty
.                             - policy set_dirty() called
- policy clear_dirty() called .

Result: Block is properly marked as dirty, but policy thinks it is clean
and therefore never asks us to writeback it.
This case is visible in "dmsetup status" dirty block count (which
normally decreases to 0 on a quiet device).

Fix these issues by calling clear_dirty() before calling cell_defer().
Incoming bios for that block will then be detained in the cell and
released only after clear_dirty() has completed, so the race will not
occur.

Found by inspecting the code after noticing spurious dirty counts
(scenario B).

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-09-10 11:20:47 -04:00
Mikulas Patocka
d49ec52ff6 dm crypt: fix access beyond the end of allocated space
The DM crypt target accesses memory beyond allocated space resulting in
a crash on 32 bit x86 systems.

This bug is very old (it dates back to 2.6.25 commit 3a7f6c990a "dm
crypt: use async crypto").  However, this bug was masked by the fact
that kmalloc rounds the size up to the next power of two.  This bug
wasn't exposed until 3.17-rc1 commit 298a9fa08a ("dm crypt: use per-bio
data").  By switching to using per-bio data there was no longer any
padding beyond the end of a dm-crypt allocated memory block.

To minimize allocation overhead dm-crypt puts several structures into one
block allocated with kmalloc.  The block holds struct ablkcipher_request,
cipher-specific scratch pad (crypto_ablkcipher_reqsize(any_tfm(cc))),
struct dm_crypt_request and an initialization vector.

The variable dmreq_start is set to offset of struct dm_crypt_request
within this memory block.  dm-crypt allocates the block with this size:
cc->dmreq_start + sizeof(struct dm_crypt_request) + cc->iv_size.

When accessing the initialization vector, dm-crypt uses the function
iv_of_dmreq, which performs this calculation: ALIGN((unsigned long)(dmreq
+ 1), crypto_ablkcipher_alignmask(any_tfm(cc)) + 1).

dm-crypt allocated "cc->iv_size" bytes beyond the end of dm_crypt_request
structure.  However, when dm-crypt accesses the initialization vector, it
takes a pointer to the end of dm_crypt_request, aligns it, and then uses
it as the initialization vector.  If the end of dm_crypt_request is not
aligned on a crypto_ablkcipher_alignmask(any_tfm(cc)) boundary the
alignment causes the initialization vector to point beyond the allocated
space.

Fix this bug by calculating the variable iv_size_padding and adding it
to the allocated size.

Also correct the alignment of dm_crypt_request.  struct dm_crypt_request
is specific to dm-crypt (it isn't used by the crypto subsystem at all),
so it is aligned on __alignof__(struct dm_crypt_request).

Also align per_bio_data_size on ARCH_KMALLOC_MINALIGN, so that it is
aligned as if the block was allocated with kmalloc.

Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-28 14:24:09 -04:00
Christoph Lameter
1f125e76f5 md: Replace __this_cpu_ptr with raw_cpu_ptr
__this_cpu_ptr is being phased out.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:47 -04:00
NeilBrown
cb8b12b5d8 md/raid10: always initialise ->state on newly allocated r10_bio
Most places which allocate an r10_bio zero the ->state, some don't.
As the r10_bio comes from a mempool, and the allocation function uses
kzalloc it is often zero anyway.  But sometimes it isn't and it is
best to be safe.

I only noticed this because of the bug fixed by an earlier patch
where the r10_bios allocated for a reshape were left around to
be used by a subsequent resync.  In that case the R10BIO_IsReshape
flag caused problems.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
e337aead3a md/raid10: avoid memory leak on error path during reshape.
If raid10 reshape fails to find somewhere to read a block
from, it returns without freeing memory...

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
b39685526f md/raid10: Fix memory leak when raid10 reshape completes.
When a raid10 commences a resync/recovery/reshape it allocates
some buffer space.
When a resync/recovery completes the buffer space is freed.  But not
when the reshape completes.
This can result in a small memory leak.

There is a subtle side-effect of this bug.  When a RAID10 is reshaped
to a larger array (more devices), the reshape is immediately followed
by a "resync" of the new space.  This "resync" will use the buffer
space which was allocated for "reshape".  This can cause problems
including a "BUG" in the SCSI layer.  So this is suitable for -stable.

Cc: stable@vger.kernel.org (v3.5+)
Fixes: 3ea7daa5d7
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
ce0b0a4695 md/raid10: fix memory leak when reshaping a RAID10.
raid10 reshape clears unwanted bits from a bio->bi_flags using
a method which, while clumsy, worked until 3.10 when BIO_OWNS_VEC
was added.
Since then it clears that bit but shouldn't.  This results in a
memory leak.

So change to used the approved method of clearing unwanted bits.

As this causes a memory leak which can consume all of memory
the fix is suitable for -stable.

Fixes: a38352e0ac
Cc: stable@vger.kernel.org (v3.10+)
Reported-by: mdraid.pkoch@dfgh.net (Peter Koch)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
9c4bdf697c md/raid6: avoid data corruption during recovery of double-degraded RAID6
During recovery of a double-degraded RAID6 it is possible for
some blocks not to be recovered properly, leading to corruption.

If a write happens to one block in a stripe that would be written to a
missing device, and at the same time that stripe is recovering data
to the other missing device, then that recovered data may not be written.

This patch skips, in the double-degraded case, an optimisation that is
only safe for single-degraded arrays.

Bug was introduced in 2.6.32 and fix is suitable for any kernel since
then.  In an older kernel with separate handle_stripe5() and
handle_stripe6() functions the patch must change handle_stripe6().

Cc: stable@vger.kernel.org (2.6.32+)
Fixes: 6c0069c0ae
Cc: Yuri Tikhonov <yur@emcraft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Tested-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1090423
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
2014-08-18 14:49:46 +10:00
NeilBrown
a40687ff73 md/raid5: avoid livelock caused by non-aligned writes.
If a stripe in a raid6 array received a write to each data block while
the array is degraded, and if any of these writes to a missing device
are not page-aligned, then a live-lock happens.

In this case the P and Q blocks need to be read so that the part of
the missing block which is *not* being updated by the write can be
constructed.  Due to a logic error, these blocks are not loaded, so
the update cannot proceed and the stripe is 'handled' repeatedly in an
infinite loop.

This bug is unlikely as most writes are page aligned.  However as it
can lead to a livelock it is suitable for -stable.  It was introduced
in 3.16.

Cc: stable@vger.kernel.org (v3.16)
Fixed: 67f455486d
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-18 14:49:41 +10:00
Linus Torvalds
ba368991f6 . Allow the thin target to paired with any size external origin; also
allow thin snapshots to be larger than the external origin.
 
 . Add support for quickly loading a repetitive pattern into the
   dm-switch target.
 
 . Use per-bio data in the dm-crypt target instead of always using a
   mempool for each allocation.  Required switching to kmalloc alignment
   for the bio slab.
 
 . Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag
 
 . Fix the dm-cache and dm-thin targets' export of the minimum_io_size to
   match the data block size -- this fixes an issue where mkfs.xfs would
   improperly infer raid striping was in place on the underlying storage.
 
 . Small cleanups in dm-io, dm-mpath and dm-cache
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Merge tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:

 - Allow the thin target to paired with any size external origin; also
   allow thin snapshots to be larger than the external origin.

 - Add support for quickly loading a repetitive pattern into the
   dm-switch target.

 - Use per-bio data in the dm-crypt target instead of always using a
   mempool for each allocation.  Required switching to kmalloc alignment
   for the bio slab.

 - Fix DM core to properly stack the QUEUE_FLAG_NO_SG_MERGE flag

 - Fix the dm-cache and dm-thin targets' export of the minimum_io_size
   to match the data block size -- this fixes an issue where mkfs.xfs
   would improperly infer raid striping was in place on the underlying
   storage.

 - Small cleanups in dm-io, dm-mpath and dm-cache

* tag 'dm-3.17-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: propagate QUEUE_FLAG_NO_SG_MERGE
  dm switch: efficiently support repetitive patterns
  dm switch: factor out switch_region_table_read
  dm cache: set minimum_io_size to cache's data block size
  dm thin: set minimum_io_size to pool's data block size
  dm crypt: use per-bio data
  block: use kmalloc alignment for bio slab
  dm table: make dm_table_supports_discards static
  dm cache metadata: use dm-space-map-metadata.h defined size limits
  dm cache: fail migrations in the do_worker error path
  dm cache: simplify deferred set reference count increments
  dm thin: relax external origin size constraints
  dm thin: switch to an atomic_t for tracking pending new block preparations
  dm mpath: eliminate pg_ready() wrapper
  dm io: simplify dec_count and sync_io
2014-08-14 09:17:56 -06:00
Linus Torvalds
d429a3639c Merge branch 'for-3.17/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:
 "Nothing out of the ordinary here, this pull request contains:

   - A big round of fixes for bcache from Kent Overstreet, Slava Pestov,
     and Surbhi Palande.  No new features, just a lot of fixes.

   - The usual round of drbd updates from Andreas Gruenbacher, Lars
     Ellenberg, and Philipp Reisner.

   - virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei
     has taken it one step further and added support for actually using
     more than one queue.

   - Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to
     compliment the the default behavior of adding to the tail of the
     queue.  From Douglas Gilbert"

* 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits)
  bcache: Drop unneeded blk_sync_queue() calls
  bcache: add mutex lock for bch_is_open
  bcache: Correct printing of btree_gc_max_duration_ms
  bcache: try to set b->parent properly
  bcache: fix memory corruption in init error path
  bcache: fix crash with incomplete cache set
  bcache: Fix more early shutdown bugs
  bcache: fix use-after-free in btree_gc_coalesce()
  bcache: Fix an infinite loop in journal replay
  bcache: fix crash in bcache_btree_node_alloc_fail tracepoint
  bcache: bcache_write tracepoint was crashing
  bcache: fix typo in bch_bkey_equal_header
  bcache: Allocate bounce buffers with GFP_NOWAIT
  bcache: Make sure to pass GFP_WAIT to mempool_alloc()
  bcache: fix uninterruptible sleep in writeback thread
  bcache: wait for buckets when allocating new btree root
  bcache: fix crash on shutdown in passthrough mode
  bcache: fix lockdep warnings on shutdown
  bcache allocator: send discards with correct size
  bcache: Fix to remove the rcu_sched stalls.
  ...
2014-08-14 09:10:21 -06:00
Linus Torvalds
2213d7c29a md updates for 3.17
Most interesting is that md devices (major == 9) with
 minor numbers of 512 or more will no longer be created
 simply by opening a block device file.  They can only
 be created by writing to
    /sys/module/md_mod/parameters/new_array
 The 'auto-create-on-open' semantic is cumbersome and we
 need to start moving away from it.
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Merge tag 'md/3.17' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Most interesting is that md devices (major == 9) with minor numbers of
  512 or more will no longer be created simply by opening a block device
  file.  They can only be created by writing to

      /sys/module/md_mod/parameters/new_array

  The 'auto-create-on-open' semantic is cumbersome and we need to start
  moving away from it"

* tag 'md/3.17' of git://neil.brown.name/md:
  md: don't allow bitmap file to be added to raid0/linear.
  md/raid0: check for bitmap compatability when changing raid levels.
  md: Recovery speed is wrong
  md: disable probing for md devices 512 and over.
  md/raid1,raid10: always abort recover on write error.
2014-08-11 07:02:35 -07:00
Jeff Moyer
200612ec33 dm table: propagate QUEUE_FLAG_NO_SG_MERGE
Commit 05f1dd5 ("block: add queue flag for disabling SG merging")
introduced a new queue flag: QUEUE_FLAG_NO_SG_MERGE.  This gets set by
default in blk_mq_init_queue for mq-enabled devices.  The effect of
the flag is to bypass the SG segment merging.  Instead, the
bio->bi_vcnt is used as the number of hardware segments.

With a device mapper target on top of a device with
QUEUE_FLAG_NO_SG_MERGE set, we can end up sending down more segments
than a driver is prepared to handle.  I ran into this when backporting
the virtio_blk mq support.  It triggerred this BUG_ON, in
virtio_queue_rq:

        BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);

The queue's max is set here:
        blk_queue_max_segments(q, vblk->sg_elems-2);

Basically, what happens is that a bio is built up for the dm device
(which does not have the QUEUE_FLAG_NO_SG_MERGE flag set) using
bio_add_page.  That path will call into __blk_recalc_rq_segments, so
what you end up with is bi_phys_segments being much smaller than bi_vcnt
(and bi_vcnt grows beyond the maximum sg elements).  Then, when the bio
is submitted, it gets cloned.  When the cloned bio is submitted, it will
end up in blk_recount_segments, here:

        if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags))
                bio->bi_phys_segments = bio->bi_vcnt;

and now we've set bio->bi_phys_segments to a number that is beyond what
was registered as queue_max_segments by the driver.

The right way to fix this is to propagate the queue flag up the stack.

The rules for propagating the flag are simple:
- if the flag is set for any underlying device, it must be set for the
  upper device
- consequently, if the flag is not set for any underlying device, it
  should not be set for the upper device.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.16+
2014-08-10 20:54:49 -04:00
NeilBrown
d66b1b395a md: don't allow bitmap file to be added to raid0/linear.
An array can only accept a bitmap if it will call bitmap_daemon_work
periodically, which means it needs a thread running.

If there is no thread, don't allow a bitmap to be added.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08 15:43:20 +10:00
NeilBrown
a8461a61c2 md/raid0: check for bitmap compatability when changing raid levels.
If an array has a bitmap, then it cannot be converted to raid0.

Reported-by: Xiao Ni <xni@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08 15:33:17 +10:00
Xiao Ni
ac7e50a383 md: Recovery speed is wrong
When we calculate the speed of recovery, the numerator that contains
the recovery done sectors.  It's need to subtract the sectors which
don't finish recovery.

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-08 12:11:25 +10:00
Linus Torvalds
98959948a7 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:

 - Move the nohz kick code out of the scheduler tick to a dedicated IPI,
   from Frederic Weisbecker.

  This necessiated quite some background infrastructure rework,
  including:

   * Clean up some irq-work internals
   * Implement remote irq-work
   * Implement nohz kick on top of remote irq-work
   * Move full dynticks timer enqueue notification to new kick
   * Move multi-task notification to new kick
   * Remove unecessary barriers on multi-task notification

 - Remove proliferation of wait_on_bit() action functions and allow
   wait_on_bit_action() functions to support a timeout.  (Neil Brown)

 - Another round of sched/numa improvements, cleanups and fixes.  (Rik
   van Riel)

 - Implement fast idling of CPUs when the system is partially loaded,
   for better scalability.  (Tim Chen)

 - Restructure and fix the CPU hotplug handling code that may leave
   cfs_rq and rt_rq's throttled when tasks are migrated away from a dead
   cpu.  (Kirill Tkhai)

 - Robustify the sched topology setup code.  (Peterz Zijlstra)

 - Improve sched_feat() handling wrt.  static_keys (Jason Baron)

 - Misc fixes.

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  sched/fair: Fix 'make xmldocs' warning caused by missing description
  sched: Use macro for magic number of -1 for setparam
  sched: Robustify topology setup
  sched: Fix sched_setparam() policy == -1 logic
  sched: Allow wait_on_bit_action() functions to support a timeout
  sched: Remove proliferation of wait_on_bit() action functions
  sched/numa: Revert "Use effective_load() to balance NUMA loads"
  sched: Fix static_key race with sched_feat()
  sched: Remove extra static_key*() function indirection
  sched/rt: Fix replenish_dl_entity() comments to match the current upstream code
  sched: Transform resched_task() into resched_curr()
  sched/deadline: Kill task_struct->pi_top_task
  sched: Rework check_for_tasks()
  sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime()
  sched/fair: Disable runtime_enabled on dying rq
  sched/numa: Change scan period code to match intent
  sched/numa: Rework best node setting in task_numa_migrate()
  sched/numa: Examine a task move when examining a task swap
  sched/numa: Simplify task_numa_compare()
  sched/numa: Use effective_load() to balance NUMA loads
  ...
2014-08-04 16:23:30 -07:00
Kent Overstreet
0781c8748c bcache: Drop unneeded blk_sync_queue() calls
this is needed for the queue/block device we created (it's done by
blk_cleanup_queue() which we do call) - but calling it for the block devices we
only opened is pointless.

Change-Id: I53dfded14ed15b9581d10ca8399d5e1b3abbf9f2
2014-08-04 15:23:04 -07:00
Jianjian Huo
789d21dbd9 bcache: add mutex lock for bch_is_open
Since bch_is_open will iterate linked list bch_cache_sets and
uncached_devices, it needs bch_register_lock.

Signed-off-by: Jianjian Huo <samuel.huo@gmail.com>
2014-08-04 15:23:04 -07:00
Surbhi Palande
5b25abade2 bcache: Correct printing of btree_gc_max_duration_ms
time_stats::btree_gc_max_duration_mc is not bit shifted by 8

Fixes BUG #138

Change-Id: I44fc6e1d0579674016acc533f1a546b080e5371a
Signed-off-by: Surbhi Palande <sap@daterainc.com>
2014-08-04 15:23:04 -07:00
Slava Pestov
2452cc8906 bcache: try to set b->parent properly
bcache_flash_dev.ktest would reliably crash with 8k and 16k bucket size
before; now it passes.

Change-Id: Ib542232235e39298c3a7548fe52b645cabb823d1
2014-08-04 15:23:04 -07:00
Slava Pestov
c9a78332b4 bcache: fix memory corruption in init error path
If register_cache_set() failed, we would touch ca->set after
it had already been freed. Also, fix an assertion to catch
this.

Change-Id: I748e5f5b223e2d9b2602075dec2f997cced2394d
2014-08-04 15:23:04 -07:00
Slava Pestov
bf0c55c986 bcache: fix crash with incomplete cache set
Change-Id: I6abde52afe917633480caaf4e2518f42a816d886
2014-08-04 15:23:04 -07:00
Kent Overstreet
d83353b319 bcache: Fix more early shutdown bugs
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:04 -07:00
Slava Pestov
400ffaa2ac bcache: fix use-after-free in btree_gc_coalesce()
If we goto out_nocoalesce after we free new_nodes[0], we end up freeing
new_nodes[0] again. This was generating a lockdep warning. The fix is
to set new_nodes[0] to NULL, since the out_nocoalesce path safely
ignores NULL entries in the new_nodes array.

This regression was introduced in 2d7f9531.

Change-Id: I76564d7257800583214376b4bacf236cda90c89c
2014-08-04 15:23:04 -07:00
Kent Overstreet
6b708de64a bcache: Fix an infinite loop in journal replay
When running with multiple cache devices, if one of the devices has a completely
empty journal but we'd already found some journal entries on a previosu device
we'd go into an infinite loop.

Change-Id: I1dcdc0d738192746de28f40e8b08825b0dea5e2b
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Slava Pestov
913dc33fb2 bcache: fix crash in bcache_btree_node_alloc_fail tracepoint
'b' was NULL.

Change-Id: Icac0fd04afa2d23f213d96d51afd53374e6dd0c0
2014-08-04 15:23:03 -07:00
Slava Pestov
60ae81eee8 bcache: bcache_write tracepoint was crashing
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Slava Pestov
8e09480806 bcache: fix typo in bch_bkey_equal_header
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Kent Overstreet
501d52a90c bcache: Allocate bounce buffers with GFP_NOWAIT
There's no point in blocking on these allocations, since our fallback paths will
probably go faster than blocking.

Change-Id: I733ca202c25cb36bde02607a0a60552229a4241c
2014-08-04 15:23:03 -07:00
Kent Overstreet
bcf090e004 bcache: Make sure to pass GFP_WAIT to mempool_alloc()
this was very wrong - mempool_alloc() only guarantees success with GFP_WAIT.
bcache uses GFP_NOWAIT in various other places where we have a fallback,
circuits must've gotten crossed when writing this code or something.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Slava Pestov
9e5c353510 bcache: fix uninterruptible sleep in writeback thread
There were two issues here:

- writeback thread did not start until the device first became dirty
- writeback thread used uninterruptible sleep once running

Without this patch I see kernel warnings printed and a load average of
1.52 after booting my test VM. With this patch the warnings are gone and
the load average is near 0.00 as expected.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Slava Pestov
c5aa4a3157 bcache: wait for buckets when allocating new btree root
Tested:
- sometimes bcache_tier test would hang on startup with a failure
  to allocate the btree root -- no longer seeing this

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:03 -07:00
Slava Pestov
a664d0f05a bcache: fix crash on shutdown in passthrough mode
We never started the writeback thread in this case, so don't stop it.
2014-08-04 15:23:03 -07:00
Slava Pestov
e5112201c1 bcache: fix lockdep warnings on shutdown 2014-08-04 15:23:03 -07:00
Slava Pestov
8b326d3a2a bcache allocator: send discards with correct size 2014-08-04 15:23:03 -07:00
Surbhi Palande
dbd810ab67 bcache: Fix to remove the rcu_sched stalls.
while loop was executing infinitely.
This fix ends the while loop gracefully.

Signed-off-by: Surbhi Palande <sap@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:02 -07:00
Kent Overstreet
9aa61a992a bcache: Fix a journal replay bug
journal replay wansn't validating pointers with bch_extent_invalid() before
derefing, fixed

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:02 -07:00
Kent Overstreet
5b1016e62f bcache: Fix a bug when detaching
After detaching a backing device from a cache set, a bit wasn't getting
reset meaning the second detach wouldn't work correctly.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04 15:23:02 -07:00
Mikulas Patocka
56b1ebf2d9 dm switch: efficiently support repetitive patterns
Add support for quickly loading a repetitive pattern into the
dm-switch target.

In the "set_regions_mappings" message, the user may now use "Rn,m" as
one of the arguments.  "n" and "m" are hexadecimal numbers.  The "Rn,m"
argument repeats the last "n" arguments in the following "m" slots.

For example:
dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
is equivalent to
dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
:1 :2 :1 :2 :1 :2 :1 :2 :1 :2

Requested-by: Jay Wang <jwang@nimblestorage.com>
Tested-by: Jay Wang <jwang@nimblestorage.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:37 -04:00
Mikulas Patocka
99eb1908e6 dm switch: factor out switch_region_table_read
Move code that reads the table to a switch_region_table_read.
It will be needed for the next commit.  No functional change.

Tested-by: Jay Wang <jwang@nimblestorage.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:36 -04:00
Mike Snitzer
b02465308f dm cache: set minimum_io_size to cache's data block size
Before, if the block layer's limit stacking didn't establish an
optimal_io_size that was compatible with the cache's data block size
we'd set optimal_io_size to the data block size and minimum_io_size to 0
(which the block layer adjusts to be physical_block_size).

Update cache_io_hints() to set both minimum_io_size and optimal_io_size
to the cache's data block size.  This fixes an issue where mkfs.xfs
would create more XFS Allocation Groups on cache volumes than on a
normal linear LV of comparable size.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:36 -04:00
Mike Snitzer
fdfb4c8c1a dm thin: set minimum_io_size to pool's data block size
Before, if the block layer's limit stacking didn't establish an
optimal_io_size that was compatible with the thin-pool's data block size
we'd set optimal_io_size to the data block size and minimum_io_size to 0
(which the block layer adjusts to be physical_block_size).

Update pool_io_hints() to set both minimum_io_size and optimal_io_size
to the thin-pool's data block size.  This fixes an issue reported where
mkfs.xfs would create more XFS Allocation Groups on thinp volumes than
on a normal linear LV of comparable size, see:
https://bugzilla.redhat.com/show_bug.cgi?id=1003227

Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:35 -04:00
Mikulas Patocka
298a9fa08a dm crypt: use per-bio data
Change dm-crypt so that it uses auxiliary data allocated with the bio.

Dm-crypt requires two allocations per request - struct dm_crypt_io and
struct ablkcipher_request (with other data appended to it).  It
previously only used mempool allocations.

Some requests may require more dm_crypt_ios and ablkcipher_requests,
however most requests need just one of each of these two structures to
complete.

This patch changes it so that the first dm_crypt_io and ablkcipher_request
are allocated with the bio (using target per_bio_data_size option).  If
the request needs additional values, they are allocated from the mempool.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:35 -04:00
Mikulas Patocka
a7ffb6a533 dm table: make dm_table_supports_discards static
The function dm_table_supports_discards is only called from
dm-table.c:dm_table_set_restrictions().  So move it above
dm_table_set_restrictions and make it static.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:34 -04:00
Mike Snitzer
895b47d798 dm cache metadata: use dm-space-map-metadata.h defined size limits
Commit 7d48935e cleaned up the persistent-data's space-map-metadata
limits by elevating them to dm-space-map-metadata.h.  Update
dm-cache-metadata to use these same limits.

The calculation for DM_CACHE_METADATA_MAX_SECTORS didn't account for the
sizeof the disk_bitmap_header.  So the supported maximum metadata size
is a bit smaller (reduced from 33423360 to 33292800 sectors).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-08-01 12:30:33 -04:00
Joe Thornber
304affaa88 dm cache: fail migrations in the do_worker error path
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:33 -04:00
Joe Thornber
8c081b52c6 dm cache: simplify deferred set reference count increments
Factor out inc_and_issue and inc_ds helpers to simplify deferred set
reference count increments.  Also cleanup cache_map to consistently call
cell_defer and inc_ds when the bio is DM_MAPIO_REMAPPED.

No functional change.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:32 -04:00
Joe Thornber
e5aea7b49f dm thin: relax external origin size constraints
Track the size of any external origin.  Previously the external origin's
size had to be a multiple of the thin-pool's block size, that is no
longer a requirement.  In addition, snapshots that are larger than the
external origin are now supported.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:32 -04:00
Joe Thornber
50f3c3efdd dm thin: switch to an atomic_t for tracking pending new block preparations
Previously we used separate boolean values to track quiescing and
copying actions.  By switching to an atomic_t we can support blocks that
need a partial copy and partial zero.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:31 -04:00
Mike Snitzer
6afbc01d75 dm mpath: eliminate pg_ready() wrapper
pg_ready() is not comprehensive in its logic and only serves to
obfuscate code.  Replace pg_ready() with the appropriate logic in
multipath_map().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:31 -04:00
Joe Thornber
97e7cdf12b dm io: simplify dec_count and sync_io
Remove the io struct off the stack in sync_io() and allocate it from
the mempool like is done in async_io().

dec_count() now always calls a callback function and always frees the io
struct back to the mempool (so sync_io and async_io share this pattern).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-08-01 12:30:30 -04:00
Anssi Hannula
44fa816bb7 dm cache: fix race affecting dirty block count
nr_dirty is updated without locking, causing it to drift so that it is
non-zero (either a small positive integer, or a very large one when an
underflow occurs) even when there are no actual dirty blocks.  This was
due to a race between the workqueue and map function accessing nr_dirty
in parallel without proper protection.

People were seeing under runs due to a race on increment/decrement of
nr_dirty, see: https://lkml.org/lkml/2014/6/3/648

Fix this by using an atomic_t for nr_dirty.

Reported-by: roma1390@gmail.com
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-08-01 12:25:22 -04:00
Greg Thelen
d8c712ea47 dm bufio: fully initialize shrinker
1d3d4437ea ("vmscan: per-node deferred work") added a flags field to
struct shrinker assuming that all shrinkers were zero filled.  The dm
bufio shrinker is not zero filled, which leaves arbitrary kmalloc() data
in flags.  So far the only defined flags bit is SHRINKER_NUMA_AWARE.
But there are proposed patches which add other bits to shrinker.flags
(e.g. memcg awareness).

Rather than simply initializing the shrinker, this patch uses kzalloc()
when allocating the dm_bufio_client to ensure that the embedded shrinker
and any other similar structures are zeroed.

This fixes theoretical over aggressive shrinking of dm bufio objects.
If the uninitialized dm_bufio_client.shrinker.flags contains
SHRINKER_NUMA_AWARE then shrink_slab() would call the dm shrinker for
each numa node rather than just once.  This has been broken since 3.12.

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.12+
2014-08-01 12:07:21 -04:00
NeilBrown
af5628f05d md: disable probing for md devices 512 and over.
The way md devices are traditionally created in the kernel
is simply to open the device with the desired major/minor number.

This can be problematic as some support tools, notably udev and
programs run by udev, can open a device just to see what is there, and
find that it has created something.  It is easy for a race to cause
udev to open an md device just after it was destroy, causing it to
suddenly re-appear.

For some time we have had an alternate way to create md devices
  echo md_somename > /sys/modules/md_mod/paramaters/new_array

This will always use a minor number of 512 or higher, which mdadm
normally avoids.
Using this makes the creation-by-opening unnecessary, but does
not disable it, so it is still there to cause problems.

This patch disable probing for devices with a major of 9 (MD_MAJOR)
and a minor of 512 and up.  This devices created by writing to
new_array cannot be re-created by opening the node in /dev.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-31 13:54:54 +10:00
NeilBrown
2446dba03f md/raid1,raid10: always abort recover on write error.
Currently we don't abort recovery on a write error if the write error
to the recovering device was triggerd by normal IO (as opposed to
recovery IO).

This means that for one bitmap region, the recovery might write to the
recovering device for a few sectors, then not bother for subsequent
sectors (as it never writes to failed devices).  In this case
the bitmap bit will be cleared, but it really shouldn't.

The result is that if the recovering device fails and is then re-added
(after fixing whatever hardware problem triggerred the failure),
the second recovery won't redo the region it was in the middle of,
so some of the device will not be recovered properly.

If we abort the recovery, the region being processes will be cancelled
(bit not cleared) and the whole region will be retried.

As the bug can result in data corruption the patch is suitable for
-stable.  For kernels prior to 3.11 there is a conflict in raid10.c
which will require care.

Original-from: jiao hui <jiaohui@bwstor.com.cn>
Reported-and-tested-by: jiao hui <jiaohui@bwstor.com.cn>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
2014-07-31 10:16:52 +10:00
Ingo Molnar
ca5bc6cd5d Merge branch 'sched/urgent' into sched/core, to merge fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-28 10:03:00 +02:00
Linus Torvalds
55ae1bd0d2 Fix the dm-thinp and dm-cache targets to disallow changing the data
device's block size.
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Merge tag 'dm-3.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Fix the dm-thinp and dm-cache targets to disallow changing the data
  device's block size"

* tag 'dm-3.16-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache metadata: do not allow the data block size to change
  dm thin metadata: do not allow the data block size to change
2014-07-18 06:25:05 -10:00
NeilBrown
743162013d sched: Remove proliferation of wait_on_bit() action functions
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:39 +02:00
Mike Snitzer
048e5a07f2 dm cache metadata: do not allow the data block size to change
The block size for the dm-cache's data device must remained fixed for
the life of the cache.  Disallow any attempt to change the cache's data
block size.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
2014-07-15 14:07:50 -04:00
Mike Snitzer
9aec8629ec dm thin metadata: do not allow the data block size to change
The block size for the thin-pool's data device must remained fixed for
the life of the thin-pool.  Disallow any attempt to change the
thin-pool's data block size.

It should be noted that attempting to change the data block size via
thin-pool table reload will be ignored as a side-effect of the thin-pool
handover that the thin-pool target does during thin-pool table reload.

Here is an example outcome of attempting to load a thin-pool table that
reduced the thin-pool's data block size from 1024K to 512K.

Before:
kernel: device-mapper: thin: 253:4: growing the data device from 204800 to 409600 blocks

After:
kernel: device-mapper: thin metadata: changing the data block size (from 2048 to 1024) is not supported
kernel: device-mapper: table: 253:4: thin-pool: Error creating metadata object
kernel: device-mapper: ioctl: error adding target to table

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
2014-07-15 14:05:26 -04:00
Linus Torvalds
67b9d76f9e . Fix DM multipath IO hang regression from 3.15 due to logic bug in
multipath_busy.  This impacted cable-pull testing and also the ability
   to boot with IPR SCSI on a POWER8 box.
 
 . Fix possible deadlock with deferred device removal by using a new
   dedicated workqueue rather than using the system workqueue.
 
 . Fix NULL pointer crash due to race condition in dm-io's wake up code
   for sync_io by using a completion.
 
 . Update dm-crypt and dm-zero author name following legal name change;
   this is important to Jana so I didn't see any reason to hold it back.
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Merge tag 'dm-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix DM multipath IO hang regression from 3.15 due to logic bug in
   multipath_busy.  This impacted cable-pull testing and also the
   ability to boot with IPR SCSI on a POWER8 box.

 - Fix possible deadlock with deferred device removal by using a new
   dedicated workqueue rather than using the system workqueue.

 - Fix NULL pointer crash due to race condition in dm-io's wake up code
   for sync_io by using a completion.

 - Update dm-crypt and dm-zero author name following legal name change;
   this is important to Jana so I didn't see any reason to hold it back.

* tag 'dm-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix IO hang due to logic bug in multipath_busy
  dm io: fix a race condition in the wake up code for sync_io
  dm crypt, dm zero: update author name following legal name change
  dm: allocate a special workqueue for deferred device removal
2014-07-11 09:33:36 -07:00
Jun'ichi Nomura
7a7a3b45fe dm mpath: fix IO hang due to logic bug in multipath_busy
Commit e80991773 ("dm mpath: push back requests instead of queueing")
modified multipath_busy() to return true if !pg_ready().  pg_ready()
checks the current state of the multipath device and may return false
even if a new IO is needed to change the state.

Bart Van Assche reported that he had multipath IO lockup when he was
performing cable pull tests.  Analysis showed that the multipath
device had a single path group with both paths active, but that the
path group itself was not active.  During the multipath device state
transitions 'queue_io' got set but nothing could clear it.  Clearing
'queue_io' only happens in __choose_pgpath(), but it won't be called
if multipath_busy() returns true due to pg_ready() returning false
when 'queue_io' is set.

As such the !pg_ready() check in multipath_busy() is wrong because new
IO will not be sent to multipath target and the multipath state change
won't happen.  That results in multipath IO lockup.

The intent of multipath_busy() is to avoid unnecessary cycles of
dequeue + request_fn + requeue if it is known that the multipath
device will requeue.

Such "busy" situations would be:
  - path group is being activated
  - there is no path and the multipath is setup to requeue if no path

Fix multipath_busy() to return "busy" early only for these specific
situations.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.15
2014-07-10 16:44:15 -04:00
Joe Thornber
10f1d5d111 dm io: fix a race condition in the wake up code for sync_io
There's a race condition between the atomic_dec_and_test(&io->count)
in dec_count() and the waking of the sync_io() thread.  If the thread
is spuriously woken immediately after the decrement it may exit,
making the on stack io struct invalid, yet the dec_count could still
be using it.

Fix this race by using a completion in sync_io() and dec_count().

Reported-by: Minfei Huang <huangminfei@ucloud.cn>
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
2014-07-10 16:44:14 -04:00
Jana Saout
bf14299f1c dm crypt, dm zero: update author name following legal name change
Signed-off-by: Jana Saout <jana@saout.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-07-10 16:44:14 -04:00
Mikulas Patocka
acfe0ad74d dm: allocate a special workqueue for deferred device removal
The commit 2c140a246d ("dm: allow remove to be deferred") introduced a
deferred removal feature for the device mapper.  When this feature is
used (by passing a flag DM_DEFERRED_REMOVE to DM_DEV_REMOVE_CMD ioctl)
and the user tries to remove a device that is currently in use, the
device will be removed automatically in the future when the last user
closes it.

Device mapper used the system workqueue to perform deferred removals.
However, some targets (dm-raid1, dm-mpath, dm-stripe) flush work items
scheduled for the system workqueue from their destructor.  If the
destructor itself is called from the system workqueue during deferred
removal, it introduces a possible deadlock - the workqueue tries to flush
itself.

Fix this possible deadlock by introducing a new workqueue for deferred
removals.  We allocate just one workqueue for all dm targets.  The
ability of dm targets to process IOs isn't dependent on deferred removal
of unused targets, so a deadlock due to shared workqueue isn't possible.

Also, cleanup local_init() to eliminate potential for returning success
on failure.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
2014-07-10 16:44:13 -04:00
NeilBrown
133d4527ea md: flush writes before starting a recovery.
When we write to a degraded array which has a bitmap, we
make sure the relevant bit in the bitmap remains set when
the write completes (so a 're-add' can quickly rebuilt a
temporarily-missing device).

If, immediately after such a write starts, we incorporate a spare,
commence recovery, and skip over the region where the write is
happening (because the 'needs recovery' flag isn't set yet),
then that write will not get to the new device.

Once the recovery finishes the new device will be trusted, but will
have incorrect data, leading to possible corruption.

We cannot set the 'needs recovery' flag when we start the write as we
do not know easily if the write will be "degraded" or not.  That
depends on details of the particular raid level and particular write
request.

This patch fixes a corruption issue of long standing and so it
suitable for any -stable kernel.  It applied correctly to 3.0 at
least and will minor editing to earlier kernels.

Reported-by: Bill <billstuff2001@sbcglobal.net>
Tested-by: Bill <billstuff2001@sbcglobal.net>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/53A518BB.60709@sbcglobal.net
Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-03 10:44:45 +10:00
NeilBrown
9bd3592032 md: make sure GET_ARRAY_INFO ioctl reports correct "clean" status
If an array has a bitmap, the when we set the "has bitmap" flag we
incorrectly clear the "is clean" flag.

"is clean" isn't really important when a bitmap is present, but it is
best to get it right anyway.

Reported-by: George Duffield <forumscollective@gmail.com>
Link: http://lkml.kernel.org/CAG__1a4MRV6gJL38XLAurtoSiD3rLBTmWpcS5HYvPpSfPR88UQ@mail.gmail.com
Fixes: 36fa30636f (v2.6.14)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-07-03 10:44:31 +10:00
Linus Torvalds
0e04c641b1 . Add dm_accept_partial_bio interface to DM core to allow DM targets
to only process a portion of a bio, the remainder being sent in the
   next bio.  This enables the old dm snapshot-origin target to only
   split write bios on chunk boundaries, read bios are now sent to the
   origin device unchanged.
 
 . Add DM core support for disabling WRITE SAME if the underlying SCSI
   layer disables it due to command failure.
 
 . Reduce lock contention in DM's bio-prison.
 
 . A few small cleanups and fixes to dm-thin and dm-era.
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Merge tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:
 "This pull request is later than I'd have liked because I was waiting
  for some performance data to help finally justify sending the
  long-standing dm-crypt cpu scalability improvements upstream.

  Unfortunately we came up short, so those dm-crypt changes will
  continue to wait, but it seems we're not far off.

   . Add dm_accept_partial_bio interface to DM core to allow DM targets
     to only process a portion of a bio, the remainder being sent in the
     next bio.  This enables the old dm snapshot-origin target to only
     split write bios on chunk boundaries, read bios are now sent to the
     origin device unchanged.

   . Add DM core support for disabling WRITE SAME if the underlying SCSI
     layer disables it due to command failure.

   . Reduce lock contention in DM's bio-prison.

   . A few small cleanups and fixes to dm-thin and dm-era"

* tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: update discard_granularity to reflect the thin-pool blocksize
  dm bio prison: implement per bucket locking in the dm_bio_prison hash table
  dm: remove symbol export for dm_set_device_limits
  dm: disable WRITE SAME if it fails
  dm era: check for a non-NULL metadata object before closing it
  dm thin: return ENOSPC instead of EIO when error_if_no_space enabled
  dm thin: cleanup noflush_work to use a proper completion
  dm snapshot: do not split read bios sent to snapshot-origin target
  dm snapshot: allocate a per-target structure for snapshot-origin target
  dm: introduce dm_accept_partial_bio
  dm: change sector_count member in clone_info from sector_t to unsigned
2014-06-12 13:33:29 -07:00
Lukas Czerner
09869de57e dm thin: update discard_granularity to reflect the thin-pool blocksize
DM thinp already checks whether the discard_granularity of the data
device is a factor of the thin-pool block size.  But when using the
dm-thin-pool's discard passdown support, DM thinp was not selecting the
max of the underlying data device's discard_granularity and the
thin-pool's block size.

Update set_discard_limits() to set discard_granularity to the max of
these values.  This enables blkdev_issue_discard() to properly align the
discards that are sent to the DM thin device on a full block boundary.
As such each discard will now cover an entire DM thin-pool block and the
block will be reclaimed.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-06-11 16:56:12 -04:00
Heinz Mauelshagen
adcc44472b dm bio prison: implement per bucket locking in the dm_bio_prison hash table
Split the single per bio-prison lock by using per bucket locking.  Per
bucket locking benefits both dm-thin and dm-cache targets by reducing
bio-prison lock contention.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-11 16:48:54 -04:00
Linus Torvalds
8d0304e69d Assorted md fixes for 3.16
Mostly performance improvements with a few corner-case bug fixes.
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Merge tag 'md/3.16' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Assorted md fixes for 3.16

  Mostly performance improvements with a few corner-case bug fixes"

* tag 'md/3.16' of git://neil.brown.name/md:
  raid5: speedup sync_request processing
  md/raid5: deadlock between retry_aligned_read with barrier io
  raid5: add an option to avoid copy data from bio to stripe cache
  md/bitmap: remove confusing code from filemap_get_page.
  raid5: avoid release list until last reference of the stripe
  md: md_clear_badblocks should return an error code on failure.
  md/raid56: Don't perform reads to support writes until stripe is ready.
  md: refuse to change shape of array if it is active but read-only
2014-06-11 08:33:41 -07:00
Eivind Sarto
053f5b6525 raid5: speedup sync_request processing
The raid5 sync_request() processing calls handle_stripe() within the context of
the resync-thread.  The resync-thread issues the first set of read requests
and this adds execution latency and slows down the scheduling of the next
sync_request().
The current rebuild/resync speed of raid5 is not much faster than what
rotational HDDs can sustain.
Testing the following patch on a 6-drive array, I can increase the rebuild
speed from 100 MB/s to 175 MB/s.
The sync_request() now just sets STRIPE_HANDLE and releases the stripe.  This
creates some more parallelism between the resync-thread and raid5 kernel daemon.

Signed-off-by: Eivind Sarto <esarto@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-06-10 11:02:01 +10:00
Linus Torvalds
3f17ea6dea Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...
2014-06-08 11:31:16 -07:00
hui jiao
2844dc32ea md/raid5: deadlock between retry_aligned_read with barrier io
A chunk aligned read increases counter active_aligned_reads and
decreases it after sub-device handle it successfully. But when a read
error occurs,  the read redispatched by raid5d, and the
active_aligned_reads will not be decreased until we can grab a stripe
head in retry_aligned_read. Now suppose, a barrier io comes, set
conf->quiesce to 2, and wait until both active_stripes and
active_aligned_reads are zero. The retried chunk aligned read gets
stuck at get_active_stripe waiting until conf->quiesce becomes 0.
Retry_aligned_read and barrier io are waiting each other now.
One possible solution is that we ignore conf->quiesce, let the retried
aligned read finish. I reproduced this deadlock and test this patch on
centos6.0

Signed-off-by: NeilBrown <neilb@suse.de>
2014-06-05 17:18:19 +10:00
Mike Snitzer
11f0431be2 dm: remove symbol export for dm_set_device_limits
There is no need for code other than DM core to use dm_set_device_limits
so remove its EXPORT_SYMBOL_GPL.  Also, cleanup a couple whitespace nits.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-04 09:46:34 -04:00
Mike Snitzer
7eee4ae2db dm: disable WRITE SAME if it fails
Add DM core support for disabling WRITE SAME on first failure to both
request-based and bio-based targets.  The need to disable WRITE SAME
stems from SCSI enabling it by default but then disabling it when it
fails.  When SCSI does this it returns "permanent target failure, do
not retry" using -EREMOTEIO.  Update DM core to only disable WRITE SAME
on failure if the returned error is -EREMOTEIO.

Commit f84cb8a4 ("dm mpath: disable WRITE SAME if it fails")
implemented multipath specific disabling of WRITE SAME if it fails.
However, as that commit detailed, the multipath-only solution doesn't go
far enough if bio-based DM targets are stacked ontop of the
request-based dm-multipath target (as is commonly done using dm-linear
to support partitions on multipath devices, via kpartx).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Alex Chen <alex.chen@huawei.com>
2014-06-04 09:45:52 -04:00
Linus Torvalds
776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Joe Thornber
989f26f5ad dm era: check for a non-NULL metadata object before closing it
era_ctr() may call era_destroy() before era->md is initialized so
era_destory() must only close the metadata object if it is not NULL.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Naohiro Aota <naota@elisp.net>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.15+
2014-06-03 13:44:08 -04:00
Mike Snitzer
af91805a49 dm thin: return ENOSPC instead of EIO when error_if_no_space enabled
Update the DM thin provisioning target's allocation failure error to be
consistent with commit a9d6ceb8 ("[SCSI] return ENOSPC on thin
provisioning failure").

The DM thin target now returns -ENOSPC rather than -EIO when
block allocation fails due to the pool being out of data space (and
the 'error_if_no_space' thin-pool feature is enabled).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-By: Joe Thornber <ejt@redhat.com>
2014-06-03 13:44:08 -04:00
Joe Thornber
e7a3e871d8 dm thin: cleanup noflush_work to use a proper completion
Factor out a pool_work interface that noflush_work makes use of to wait
for and complete work items (in terms of a proper completion struct).
Allows discontinuing the use of a custom completion in terms of atomic_t
and wait_event.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-03 13:44:07 -04:00
Mikulas Patocka
298eaa89b0 dm snapshot: do not split read bios sent to snapshot-origin target
Change the snapshot-origin target so that only write bios are split on
chunk boundary.  Read bios are passed unchanged to the underlying
device, so they don't have to be split.

Later, we could change the target so that it accepts a larger write bio
if it spans an area that is completely covered by snapshot exceptions.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-03 13:44:07 -04:00
Mikulas Patocka
599cdf3bfb dm snapshot: allocate a per-target structure for snapshot-origin target
Allocate a per-target dm_origin structure.  This is a prerequisite for
the next commit ("dm snapshot: do not split read bios sent to
snapshot-origin target") which adds a new member to this structure.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-03 13:44:07 -04:00
Mikulas Patocka
1dd40c3ecd dm: introduce dm_accept_partial_bio
The function dm_accept_partial_bio allows the target to specify how many
sectors of the current bio it will process.  If the target only wants to
accept part of the bio, it calls dm_accept_partial_bio and the DM core
sends the rest of the data in next bio.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-03 13:44:06 -04:00
Mikulas Patocka
e0d6609a5f dm: change sector_count member in clone_info from sector_t to unsigned
It is impossible to create bios with 2^23 or more sectors (the size is
stored as a 32-bit byte count in the bio). So we convert some sector_t
values to unsigned integers.

This is needed for the next commit ("dm: introduce
dm_accept_partial_bio") that replaces integer value arguments with
pointers, so the size of the integer must match.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-06-03 13:44:06 -04:00
Linus Torvalds
ca755175f2 Two md bugfixes for possible corruption when restarting reshape
If a raid5/6 reshape is restarted (After stopping and re-assembling
 the array) and the array is marked read-only (or read-auto), then
 the reshape will appear to complete immediately, without actually
 moving anything around.  This can result in corruption.
 
 There are two patches which do much the same thing in different places.
 They are separate because one is an older bug and so can be applied to
 more -stable kernels.
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Merge tag 'md/3.15-fixes' of git://neil.brown.name/md

Pull two md bugfixes from Neil Brown:
 "Two md bugfixes for possible corruption when restarting reshape

  If a raid5/6 reshape is restarted (After stopping and re-assembling
  the array) and the array is marked read-only (or read-auto), then the
  reshape will appear to complete immediately, without actually moving
  anything around.  This can result in corruption.

  There are two patches which do much the same thing in different
  places.  They are separate because one is an older bug and so can be
  applied to more -stable kernels"

* tag 'md/3.15-fixes' of git://neil.brown.name/md:
  md: always set MD_RECOVERY_INTR when interrupting a reshape thread.
  md: always set MD_RECOVERY_INTR when aborting a reshape or other "resync".
2014-06-02 17:04:37 -07:00
Linus Torvalds
681a289548 Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next
Pull block core updates from Jens Axboe:
 "It's a big(ish) round this time, lots of development effort has gone
  into blk-mq in the last 3 months.  Generally we're heading to where
  3.16 will be a feature complete and performant blk-mq.  scsi-mq is
  progressing nicely and will hopefully be in 3.17.  A nvme port is in
  progress, and the Micron pci-e flash driver, mtip32xx, is converted
  and will be sent in with the driver pull request for 3.16.

  This pull request contains:

   - Lots of prep and support patches for scsi-mq have been integrated.
     All from Christoph.

   - API and code cleanups for blk-mq from Christoph.

   - Lots of good corner case and error handling cleanup fixes for
     blk-mq from Ming Lei.

   - A flew of blk-mq updates from me:

     * Provide strict mappings so that the driver can rely on the CPU
       to queue mapping.  This enables optimizations in the driver.

     * Provided a bitmap tagging instead of percpu_ida, which never
       really worked well for blk-mq.  percpu_ida relies on the fact
       that we have a lot more tags available than we really need, it
       fails miserably for cases where we exhaust (or are close to
       exhausting) the tag space.

     * Provide sane support for shared tag maps, as utilized by scsi-mq

     * Various fixes for IO timeouts.

     * API cleanups, and lots of perf tweaks and optimizations.

   - Remove 'buffer' from struct request.  This is ancient code, from
     when requests were always virtually mapped.  Kill it, to reclaim
     some space in struct request.  From me.

   - Remove 'magic' from blk_plug.  Since we store these on the stack
     and since we've never caught any actual bugs with this, lets just
     get rid of it.  From me.

   - Only call part_in_flight() once for IO completion, as includes two
     atomic reads.  Hopefully we'll get a better implementation soon, as
     the part IO stats are now one of the more expensive parts of doing
     IO on blk-mq.  From me.

   - File migration of block code from {mm,fs}/ to block/.  This
     includes bio.c, bio-integrity.c, bounce.c, and ioprio.c.  From me,
     from a discussion on lkml.

  That should describe the meat of the pull request.  Also has various
  little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
  Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
  Bradshaw"

* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
  blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
  blk-mq: remember to start timeout handler for direct queue
  block: ensure that the timer is always added
  blk-mq: blk_mq_unregister_hctx() can be static
  blk-mq: make the sysfs mq/ layout reflect current mappings
  blk-mq: blk_mq_tag_to_rq should handle flush request
  block: remove dead code in scsi_ioctl:blk_verify_command
  blk-mq: request initialization optimizations
  block: add queue flag for disabling SG merging
  block: remove 'magic' from struct blk_plug
  blk-mq: remove alloc_hctx and free_hctx methods
  blk-mq: add file comments and update copyright notices
  blk-mq: remove blk_mq_alloc_request_pinned
  blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
  blk-mq: remove blk_mq_wait_for_tags
  blk-mq: initialize request in __blk_mq_alloc_request
  blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
  blk-mq: add helper to insert requests from irq context
  blk-mq: remove stale comment for blk_mq_complete_request()
  blk-mq: allow non-softirq completions
  ...
2014-06-02 09:29:34 -07:00
Linus Torvalds
24e19d279f A dm-cache stable fix to split discards on cache block boundaries
because dm-cache cannot yet handle discards that span cache blocks.
 
 Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.
 
 Add a 'no_space_timeout' control to dm-thinp to restore the ability to
 queue IO indefinitely when no data space is available.  This fixes a
 change in behavior that was introduced in -rc6 where the timeout
 couldn't be disabled.
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Merge tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "A dm-cache stable fix to split discards on cache block boundaries
  because dm-cache cannot yet handle discards that span cache blocks.

  Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.

  Add a 'no_space_timeout' control to dm-thinp to restore the ability to
  queue IO indefinitely when no data space is available.  This fixes a
  change in behavior that was introduced in -rc6 where the timeout
  couldn't be disabled"

* tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: really fix lockdep warning
  dm cache: always split discards on cache block boundaries
  dm thin: add 'no_space_timeout' dm-thin-pool module param
2014-05-30 12:04:56 -07:00
Shaohua Li
d592a99691 raid5: add an option to avoid copy data from bio to stripe cache
The stripe cache has two goals:
1. cache data, so next time if data can be found in stripe cache, disk access
can be avoided.
2. stable data. data is copied from bio to stripe cache and calculated parity.
data written to disk is from stripe cache, so if upper layer changes bio data,
data written to disk isn't impacted.

In my environment, I can guarantee 2 will not happen. And BDI_CAP_STABLE_WRITES
can guarantee 2 too. For 1, it's not common too. block plug mechanism will
dispatch a bunch of sequentail small requests together. And since I'm using
SSD, I'm using small chunk size. It's rare case stripe cache is really useful.

So I'd like to avoid the copy from bio to stripe cache and it's very helpful
for performance. In my 1M randwrite tests, avoid the copy can increase the
performance more than 30%.

Of course, this shouldn't be enabled by default. It's reported enabling
BDI_CAP_STABLE_WRITES can harm some workloads before, so I added an option to
control it.

Neilb:
  changed BUG_ON to WARN_ON
  Removed some assignments from raid5_build_block which are now not needed.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:47 +10:00
NeilBrown
f2e06c5884 md/bitmap: remove confusing code from filemap_get_page.
file_page_index(store, 0) is *always* 0.
This is because the bitmap sb, at 256 bytes, is *always* less than
one page.
So subtracting it has no effect and the code should be removed.

Reported-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:47 +10:00
Eivind Sarto
cf170f3fa4 raid5: avoid release list until last reference of the stripe
The (lockless) release_list reduces lock contention, but there is excessive
queueing and dequeuing of stripes on this list.  A stripe will currently be
queued on the release_list with a stripe reference count > 1.  This can cause
the raid5 kernel thread(s) to dequeue the stripe and decrement the refcount
without doing any other useful processing of the stripe.  The are two cases
when the stripe can be put on the release_list multiple times before it is
actually handled by the kernel thread(s).
1) make_request() activates the stripe processing in 4k increments.  When a
   write request is large enough to span multiple chunks of a stripe_head, the
   first 4k chunk adds the stripe to the plug list.  The next 4k chunk that is
   processed for the same stripe puts the stripe on the release_list with a
   refcount=2.  This can cause the kernel thread to process and decrement the
   stripe before the stripe us unplugged, which again will put it back on the
   release_list.
2) Whenever IO is scheduled on a stripe (pre-read and/or write), the stripe
   refcount is set to the number of active IO (for each chunk).  The stripe is
   released as each IO complete, and can be queued and dequeued multiple times
   on the release_list, until its refcount finally reached zero.

This simple patch will ensure a stripe is only queued on the release_list when
its refcount=1 and is ready to be handled by the kernel thread(s).  I added some
instrumentation to raid5 and counted the number of times striped were queued on
the release_list for a variety of write IO sizes.  Without this patch the number
of times stripes got queued on the release_list was 100-500% higher than with
the patch.  The excess queuing will increase with the IO size.  The patch also
improved throughput by 5-10%.

Signed-off-by: Eivind Sarto <esarto@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:46 +10:00
NeilBrown
8b32bf5e37 md: md_clear_badblocks should return an error code on failure.
Julia Lawall and coccinelle report that md_clear_badblocks always
returns 0, despite appearing to have an error path.
The error path really should return an error code.  ENOSPC is
reasonably appropriate.

Reported-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:46 +10:00
NeilBrown
67f455486d md/raid56: Don't perform reads to support writes until stripe is ready.
If it is found that we need to pre-read some blocks before a write
can succeed, we normally set STRIPE_DELAYED and don't actually perform
the read until STRIPE_PREREAD_ACTIVE subsequently gets set.

However for a degraded RAID6 we currently perform the reads as soon
as we see that a write is pending.  This significantly hurts
throughput.

So:
 - when handle_stripe_dirtying find a block that it wants on a device
   that is failed, set STRIPE_DELAY, instead of doing nothing, and
 - when fetch_block detects that a read might be required to satisfy a
   write, only perform the read if STRIPE_PREREAD_ACTIVE is set,
   and if we would actually need to read something to complete the write.

This also helps RAID5, though less often as RAID5 supports a
read-modify-write cycle.  For RAID5 the read is performed too early
only if the write is not a full 4K aligned write (i.e. no an
R5_OVERWRITE).

Also clean up a couple of horrible bits of formatting.

Reported-by: Patrik Horník <patrik@dsl.sk>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:46 +10:00
NeilBrown
bd8839e03b md: refuse to change shape of array if it is active but read-only
read-only arrays should not be changed.  This includes changing
the level, layout, size, or number of devices.

So reject those changes for readonly arrays.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:30 +10:00
NeilBrown
2ac295a544 md: always set MD_RECOVERY_INTR when interrupting a reshape thread.
Commit 8313b8e57f
   md: fix problem when adding device to read-only array with bitmap.

added a called to md_reap_sync_thread() which cause a reshape thread
to be interrupted (in particular, it could cause md_thread() to never even
call md_do_sync()).
However it didn't set MD_RECOVERY_INTR so ->finish_reshape() would not
know that the reshape didn't complete.

This only happens when mddev->ro is set and normally reshape threads
don't run in that situation.  But raid5 and raid10 can start a reshape
thread during "run" is the array is in the middle of a reshape.
They do this even if ->ro is set.

So it is best to set MD_RECOVERY_INTR before abortingg the
sync thread, just in case.

Though it rare for this to trigger a problem it can cause data corruption
because the reshape isn't finished properly.
So it is suitable for any stable which the offending commit was applied to.
(3.2 or later)

Fixes: 8313b8e57f
Cc: stable@vger.kernel.org (3.2+)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-29 16:59:06 +10:00
NeilBrown
3991b31ea0 md: always set MD_RECOVERY_INTR when aborting a reshape or other "resync".
If mddev->ro is set, md_to_sync will (correctly) abort.
However in that case MD_RECOVERY_INTR isn't set.

If a RESHAPE had been requested, then ->finish_reshape() will be
called and it will think the reshape was successful even though
nothing happened.

Normally a resync will not be requested if ->ro is set, but if an
array is stopped while a reshape is on-going, then when the array is
started, the reshape will be restarted.  If the array is also set
read-only at this point, the reshape will instantly appear to success,
resulting in data corruption.

Consequently, this patch is suitable for any -stable kernel.

Cc: stable@vger.kernel.org (any)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-28 13:39:39 +10:00
Hannes Reinecke
63d832c301 dm mpath: really fix lockdep warning
lockdep complains about a circular locking.  And indeed, we need to
release the lock before calling dm_table_run_md_queue_async().

As such, commit 4cdd2ad ("dm mpath: fix lock order inconsistency in
multipath_ioctl") must also be reverted in addition to fixing the
lock order in the other dm_table_run_md_queue_async() callers.

Reported-by: Bart van Assche <bvanassche@acm.org>
Tested-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-05-27 10:46:01 -04:00
Heinz Mauelshagen
f1daa838e8 dm cache: always split discards on cache block boundaries
The DM cache target cannot cope with discards that span multiple cache
blocks, so each discard bio that spans more than one cache block must
get split by the DM core.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.9+
2014-05-27 10:33:05 -04:00
Linus Torvalds
23de4a7af7 A dm-crypt fix for a cpu hotplug crash that switches from using per-cpu
data to a mempool allocation (which offers allocation with cpu locality,
 and there is no inter-cpu communication on slab allocation).
 
 A couple dm-thinp stable fixes to address "out-of-data-space" issues.
 
 A dm-multipath fix for a LOCKDEP warning introduced in 3.15-rc1.
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Merge tag 'dm-3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "A dm-crypt fix for a cpu hotplug crash that switches from using
  per-cpu data to a mempool allocation (which offers allocation with cpu
  locality, and there is no inter-cpu communication on slab allocation).

  A couple dm-thinp stable fixes to address "out-of-data-space" issues.

  A dm-multipath fix for a LOCKDEP warning introduced in 3.15-rc1"

* tag 'dm-3.15-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix lock order inconsistency in multipath_ioctl
  dm thin: add timeout to stop out-of-data-space mode holding IO forever
  dm thin: allow metadata commit if pool is in PM_OUT_OF_DATA_SPACE mode
  dm crypt: fix cpu hotplug crash by removing per-cpu structure
2014-05-21 17:57:31 +09:00
Mike Snitzer
80c578930c dm thin: add 'no_space_timeout' dm-thin-pool module param
Commit 85ad643b ("dm thin: add timeout to stop out-of-data-space mode
holding IO forever") introduced a fixed 60 second timeout.  Users may
want to either disable or modify this timeout.

Allow the out-of-data-space timeout to be configured using the
'no_space_timeout' dm-thin-pool module param.  Setting it to 0 will
disable the timeout, resulting in IO being queued until more data space
is added to the thin-pool.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
2014-05-20 14:30:36 -04:00
Mike Snitzer
4cdd2ad780 dm mpath: fix lock order inconsistency in multipath_ioctl
Commit 3e9f1be1b4 ("dm mpath: remove process_queued_ios()") did not
consistently take the multipath device's spinlock (m->lock) before
calling dm_table_run_md_queue_async() -- which takes the q->queue_lock.

Found with code inspection using hint from reported lockdep warning.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-05-14 16:12:17 -04:00
Joe Thornber
85ad643b7e dm thin: add timeout to stop out-of-data-space mode holding IO forever
If the pool runs out of data space, dm-thin can be configured to
either error IOs that would trigger provisioning, or hold those IOs
until the pool is resized.  Unfortunately, holding IOs until the pool is
resized can result in a cascade of tasks hitting the hung_task_timeout,
which may render the system unavailable.

Add a fixed timeout so IOs can only be held for a maximum of 60 seconds.
If LVM is going to resize a thin-pool that is out of data space it needs
to be prompt about it.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
2014-05-14 16:11:37 -04:00
Joe Thornber
8d07e8a5f5 dm thin: allow metadata commit if pool is in PM_OUT_OF_DATA_SPACE mode
Commit 3e1a0699 ("dm thin: fix out of data space handling") introduced
a regression in the metadata commit() method by returning an error if
the pool is in PM_OUT_OF_DATA_SPACE mode.  This oversight caused a thin
device to return errors even if the default queue_if_no_space ENOSPC
handling mode is used.

Fix commit() to only fail if pool is in PM_READ_ONLY or PM_FAIL mode.

Reported-by: qindehua@163.com
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
2014-05-14 16:11:36 -04:00
Mikulas Patocka
610f2de355 dm crypt: fix cpu hotplug crash by removing per-cpu structure
The DM crypt target used per-cpu structures to hold pointers to a
ablkcipher_request structure.  The code assumed that the work item keeps
executing on a single CPU, so it didn't use synchronization when
accessing this structure.

If a CPU is disabled by writing 0 to /sys/devices/system/cpu/cpu*/online,
the work item could be moved to another CPU.  This causes dm-crypt
crashes, like the following, because the code starts using an incorrect
ablkcipher_request:

 smpboot: CPU 7 is now offline
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000130
 IP: [<ffffffffa1862b3d>] crypt_convert+0x12d/0x3c0 [dm_crypt]
 ...
 Call Trace:
  [<ffffffffa1864415>] ? kcryptd_crypt+0x305/0x470 [dm_crypt]
  [<ffffffff81062060>] ? finish_task_switch+0x40/0xc0
  [<ffffffff81052a28>] ? process_one_work+0x168/0x470
  [<ffffffff8105366b>] ? worker_thread+0x10b/0x390
  [<ffffffff81053560>] ? manage_workers.isra.26+0x290/0x290
  [<ffffffff81058d9f>] ? kthread+0xaf/0xc0
  [<ffffffff81058cf0>] ? kthread_create_on_node+0x120/0x120
  [<ffffffff813464ac>] ? ret_from_fork+0x7c/0xb0
  [<ffffffff81058cf0>] ? kthread_create_on_node+0x120/0x120

Fix this bug by removing the per-cpu definition.  The structure
ablkcipher_request is accessed via a pointer from convert_context.
Consequently, if the work item is rescheduled to a different CPU, the
thread still uses the same ablkcipher_request.

This change may undermine performance improvements intended by commit
c0297721 ("dm crypt: scale to multiple cpus") on select hardware.  In
practice no performance difference was observed on recent hardware.  But
regardless, correctness is more important than performance.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-05-14 16:11:35 -04:00
Linus Torvalds
2ddb5998d0 Two bugfixes for md in 3.15
Both tagged for -stable.
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Merge tag 'md/3.15-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "Two bugfixes for md in 3.15

  Both tagged for -stable"

* tag 'md/3.15-fixes' of git://neil.brown.name/md:
  md: avoid possible spinning md thread at shutdown.
  md/raid10: call wait_barrier() for each request submitted.
2014-05-13 11:11:48 +09:00
NeilBrown
0f62fb220a md: avoid possible spinning md thread at shutdown.
If an md array with externally managed metadata (e.g. DDF or IMSM)
is in use, then we should not set safemode==2 at shutdown because:

1/ this is ineffective: user-space need to be involved in any 'safemode' handling,
2/ The safemode management code doesn't cope with safemode==2 on external metadata
   and md_check_recover enters an infinite loop.

Even at shutdown, an infinite-looping process can be problematic, so this
could cause shutdown to hang.

Cc: stable@vger.kernel.org (any kernel)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-06 09:49:31 +10:00
NeilBrown
cc13b1d150 md/raid10: call wait_barrier() for each request submitted.
wait_barrier() includes a counter, so we must call it precisely once
(unless balanced by allow_barrier()) for each request submitted.

Since
commit 20d0189b10
    block: Introduce new bio_split()
in 3.14-rc1, we don't call it for the extra requests generated when
we need to split a bio.

When this happens the counter goes negative, any resync/recovery will
never start, and  "mdadm --stop" will hang.

Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 20d0189b10
Cc: stable@vger.kernel.org (3.14+)
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-06 09:49:26 +10:00
Linus Torvalds
54366a7fd6 A few dm-thinp fixes for changes merged in 3.15-rc1.
A dm-verity fix for an immutable biovec regression that affects 3.14+.
 
 A dm-cache fix to properly quiesce when using writethrough mode (3.14+).
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Merge tag 'dm-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "A few dm-thinp fixes for changes merged in 3.15-rc1.

  A dm-verity fix for an immutable biovec regression that affects 3.14+.

  A dm-cache fix to properly quiesce when using writethrough mode (3.14+)"

* tag 'dm-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix writethrough mode quiescing in cache_map
  dm thin: use INIT_WORK_ONSTACK in noflush_work to avoid ODEBUG warning
  dm verity: fix biovecs hash calculation regression
  dm thin: fix rcu_read_lock being held in code that can sleep
  dm thin: irqsave must always be used with the pool->lock spinlock
2014-05-02 14:14:02 -07:00
Mike Snitzer
131cd131a9 dm cache: fix writethrough mode quiescing in cache_map
Commit 2ee57d5873 ("dm cache: add passthrough mode") inadvertently
removed the deferred set reference that was taken in cache_map()'s
writethrough mode support.  Restore taking this reference.

This issue was found with code inspection.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
2014-05-01 16:14:24 -04:00
Mike Snitzer
fbcde3d8b9 dm thin: use INIT_WORK_ONSTACK in noflush_work to avoid ODEBUG warning
Use INIT_WORK_ONSTACK to silence "ODEBUG: object is on stack, but not
annotated".

Reported-by: Zdeněk Kabeláč <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-04-29 11:22:04 -04:00
Peter Zijlstra
4e857c58ef arch: Mass conversion of smp_mb__*()
Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18 14:20:48 +02:00
Linus Torvalds
23c1a60e2e One BUG fix for md for recent commit
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Merge tag '3.15-fixes' of git://neil.brown.name/md

Pull md bugfix from Neil Brown:
 "One BUG fix for md for recent commit"

* tag '3.15-fixes' of git://neil.brown.name/md:
  raid5: fix a race of stripe count check
2014-04-17 10:51:01 -07:00
Shaohua Li
c7a6d35e46 raid5: fix a race of stripe count check
I hit another BUG_ON with e240c1839d. In __get_priority_stripe(),
stripe count equals to 0 initially. Between atomic_inc and BUG_ON,
get_active_stripe() finds the stripe. So the stripe count isn't 1 any more.

V2: keeps the BUG_ON suggested by Neil.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-17 17:05:28 +10:00
Jens Axboe
b4f42e2831 block: remove struct request buffer member
This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.

Convert old style drivers to just use bio_data().

For the discard payload use case, just reference the page
in the bio.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-15 14:03:02 -06:00
Milan Broz
3a7745215e dm verity: fix biovecs hash calculation regression
Commit 003b5c5719 ("block: Convert drivers
to immutable biovecs") incorrectly converted biovec iteration in
dm-verity to always calculate the hash from a full biovec, but the
function only needs to calculate the hash from part of the biovec (up to
the calculated "todo" value).

Fix this issue by limiting hash input to only the requested data size.

This problem was identified using the cryptsetup regression test for
veritysetup (verity-compat-test).

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
2014-04-15 12:19:24 -04:00
Linus Torvalds
7f87307818 Just a few md patches for the 3.15 merge window.
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Merge tag 'md/3.15' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "Just a few md patches for the 3.15 merge window.

  Not much happening in md/raid at the moment.  Just a few bug fixes
  (one for -stable) and a couple of performance tweaks"

* tag 'md/3.15' of git://neil.brown.name/md:
  raid5: get_active_stripe avoids device_lock
  raid5: make_request does less prepare wait
  md: avoid oops on unload if some process is in poll or select.
  md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails.
  md/bitmap: don't abuse i_writecount for bitmap files.
2014-04-11 17:20:38 -07:00
Shaohua Li
e240c1839d raid5: get_active_stripe avoids device_lock
For sequential workload (or request size big workload), get_active_stripe can
find cached stripe. In this case, we always hold device_lock, which exposes a
lot of lock contention for such workload. If stripe count isn't 0, we don't
need hold the lock actually, since we just increase its count. And this is the
hot code path for such workload. Unfortunately we must delete the BUG_ON.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 14:42:42 +10:00
Shaohua Li
27c0f68f07 raid5: make_request does less prepare wait
In NUMA machine, prepare_to_wait/finish_wait in make_request exposes a
lot of contention for sequential workload (or big request size
workload). For such workload, each bio includes several stripes. So we
can just do prepare_to_wait/finish_wait once for the whold bio instead
of every stripe.  This reduces the lock contention completely for such
workload. Random workload might have the similar lock contention too,
but I didn't see it yet, maybe because my stroage is still not fast
enough.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 14:42:38 +10:00
NeilBrown
e2f23b606b md: avoid oops on unload if some process is in poll or select.
If md-mod is unloaded while some process is in poll() or select(),
then that process maintains a pointer to md_event_waiters, and when
the try to unlink from that list, they will oops.

The procfs infrastructure ensures that ->poll won't be called after
remove_proc_entry, but doesn't provide a wait_queue_head for us to
use, and the waitqueue code doesn't provide a way to remove all
listeners from a waitqueue.

So we need to:
 1/ make sure no further references to md_event_waiters are taken (by
    setting md_unloading)
 2/ wake up all processes currently waiting, and
 3/ wait until all those processes have disconnected from our
    wait_queue_head.

Reported-by: "majianpeng" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 14:42:34 +10:00
NeilBrown
da1aab3dca md/raid1: r1buf_pool_alloc: free allocate pages when subsequent allocation fails.
When performing a user-request check/repair (MD_RECOVERY_REQUEST is set)
on a raid1, we allocate multiple bios each with their own set of pages.

If the page allocations for one bio fails, we currently do *not* free
the pages allocated for the previous bios, nor do we free the bio itself.

This patch frees all the already-allocate pages, and makes sure that
all the bios are freed as well.

This bug can cause a memory leak which can ultimately OOM a machine.
It was introduced in 3.10-rc1.

Fixes: a07876064a
Cc: Kent Overstreet <koverstreet@google.com>
Cc: stable@vger.kernel.org (3.10+)
Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 14:42:23 +10:00
NeilBrown
035328c202 md/bitmap: don't abuse i_writecount for bitmap files.
md bitmap code currently tries to use i_writecount to stop any other
process from writing to out bitmap file.  But that is really an abuse
and has bit-rotted so locking is all wrong.

So discard that - root should be allowed to shoot self in foot.

Still use it in a much less intrusive way to stop the same file being
used as bitmap on two different array, and apply other checks to
ensure the file is at least vaguely usable for bitmap storage
(is regular, is open for write.  Support for ->bmap is already checked
elsewhere).

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09 12:26:59 +10:00
Joe Thornber
b10ebd34cc dm thin: fix rcu_read_lock being held in code that can sleep
Commit c140e1c4e2 ("dm thin: use per thin device deferred bio lists")
introduced the use of an rculist for all active thin devices.  The use
of rcu_read_lock() in process_deferred_bios() can result in a BUG if a
dm_bio_prison_cell must be allocated as a side-effect of bio_detain():

 BUG: sleeping function called from invalid context at mm/mempool.c:203
 in_atomic(): 1, irqs_disabled(): 0, pid: 6, name: kworker/u8:0
 3 locks held by kworker/u8:0/6:
   #0:  ("dm-" "thin"){.+.+..}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550
   #1:  ((&pool->worker)){+.+...}, at: [<ffffffff8106be42>] process_one_work+0x192/0x550
   #2:  (rcu_read_lock){.+.+..}, at: [<ffffffff816360b5>] do_worker+0x5/0x4d0

We can't process deferred bios with the rcu lock held, since
dm_bio_prison_cell allocation may block if the bio-prison's cell mempool
is exhausted.

To fix:

- Introduce a refcount and completion field to each thin_c

- Add thin_get/put methods for adjusting the refcount.  If the refcount
  hits zero then the completion is triggered.

- Initialise refcount to 1 when creating thin_c

- When iterating the active_thins list we thin_get() whilst the rcu
  lock is held.

- After the rcu lock is dropped we process the deferred bios for that
  thin.

- When destroying a thin_c we thin_put() and then wait for the
  completion -- to avoid a race between the worker thread iterating
  from that thin_c and destroying the thin_c.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-04-08 10:18:35 -04:00
Joe Thornber
5e3283e292 dm thin: irqsave must always be used with the pool->lock spinlock
Commit c140e1c4e2 ("dm thin: use per thin device deferred bio lists")
incorrectly stopped disabling irqs when taking the pool's spinlock.

Irqs must be disabled when taking the pool's spinlock otherwise a thread
could spin_lock(), then get interrupted to service thin_endio() in
interrupt context, which would then deadlock in spin_lock_irqsave().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-04-08 10:10:51 -04:00
Linus Torvalds
04535d273e . Fix dm-cache corruption caused by discard_block_size >
cache_block_size
 
 . Fix a lock-inversion detected by LOCKDEP in dm-cache
 
 . Fix a dangling bio bug in the dm-thinp target's process_deferred_bios
   error path
 
 . Fix corruption due to non-atomic transaction commit which allowed a
   metadata superblock to be written before all other metadata was
   successfully written -- this is common to all targets that use the
   persistent-data library's transaction manager (dm-thinp, dm-cache and
   dm-era).
 
 . Various small cleanups in the DM core
 
 . Add the dm-era target which is useful for keeping track of which
   blocks were written within a user defined period of time called an
   'era'.  Use cases include tracking changed blocks for backup software,
   and partially invalidating the contents of a cache to restore cache
   coherency after rolling back a vendor snapshot.
 
 . Improve the on-disk layout of multithreaded writes to the dm-thin-pool
   by splitting the pool's deferred bio list to be a per-thin device list
   and then sorting that list using an rb_tree.  The subsequent read
   throughput of the data written via multiple threads improved by ~70%.
 
 . Simplify the multipath target's handling of queuing IO by pushing
   requests back to the request queue rather than queueing the IO
   internally.
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Merge tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:

 - Fix dm-cache corruption caused by discard_block_size > cache_block_size

 - Fix a lock-inversion detected by LOCKDEP in dm-cache

 - Fix a dangling bio bug in the dm-thinp target's process_deferred_bios
   error path

 - Fix corruption due to non-atomic transaction commit which allowed a
   metadata superblock to be written before all other metadata was
   successfully written -- this is common to all targets that use the
   persistent-data library's transaction manager (dm-thinp, dm-cache and
   dm-era).

 - Various small cleanups in the DM core

 - Add the dm-era target which is useful for keeping track of which
   blocks were written within a user defined period of time called an
   'era'.  Use cases include tracking changed blocks for backup
   software, and partially invalidating the contents of a cache to
   restore cache coherency after rolling back a vendor snapshot.

 - Improve the on-disk layout of multithreaded writes to the
   dm-thin-pool by splitting the pool's deferred bio list to be a
   per-thin device list and then sorting that list using an rb_tree.
   The subsequent read throughput of the data written via multiple
   threads improved by ~70%.

 - Simplify the multipath target's handling of queuing IO by pushing
   requests back to the request queue rather than queueing the IO
   internally.

* tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
  dm cache: fix a lock-inversion
  dm thin: sort the per thin deferred bios using an rb_tree
  dm thin: use per thin device deferred bio lists
  dm thin: simplify pool_is_congested
  dm thin: fix dangling bio in process_deferred_bios error path
  dm mpath: print more useful warnings in multipath_message()
  dm-mpath: do not activate failed paths
  dm mpath: remove extra nesting in map function
  dm mpath: remove map_io()
  dm mpath: reduce memory pressure when requeuing
  dm mpath: remove process_queued_ios()
  dm mpath: push back requests instead of queueing
  dm table: add dm_table_run_md_queue_async
  dm mpath: do not call pg_init when it is already running
  dm: use RCU_INIT_POINTER instead of rcu_assign_pointer in __unbind
  dm: stop using bi_private
  dm: remove dm_get_mapinfo
  dm: make dm_table_alloc_md_mempools static
  dm: take care to copy the space map roots before locking the superblock
  dm transaction manager: fix corruption due to non-atomic transaction commit
  ...
2014-04-05 18:49:31 -07:00
Joe Thornber
0596661f0a dm cache: fix a lock-inversion
When suspending a cache the policy is walked and the individual policy
hints written to the metadata via sync_metadata().  This led to this
lock order:

      policy->lock
        cache_metadata->root_lock

When loading the cache target the policy is populated while the metadata
lock is held:

      cache_metadata->root_lock
         policy->lock

Fix this potential lock-inversion (ABBA) deadlock in sync_metadata() by
ensuring the cache_metadata root_lock is held whilst all the hints are
written, rather than being repeatedly locked while policy->lock is held
(as was the case with each callout that policy_walk_mappings() made to
the old save_hint() method).

Found by turning on the CONFIG_PROVE_LOCKING ("Lock debugging: prove
locking correctness") build option.  However, it is not clear how the
LOCKDEP reported paths can lead to a deadlock since the two paths,
suspending a target and loading a target, never occur at the same time.
But that doesn't mean the same lock-inversion couldn't have occurred
elsewhere.

Reported-by: Marian Csontos <mcsontos@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-04-04 14:53:05 -04:00
Mike Snitzer
67324ea188 dm thin: sort the per thin deferred bios using an rb_tree
A thin-pool will allocate blocks using FIFO order for all thin devices
which share the thin-pool.  Because of this simplistic allocation the
thin-pool's space can become fragmented quite easily; especially when
multiple threads are requesting blocks in parallel.

Sort each thin device's deferred_bio_list based on logical sector to
help reduce fragmentation of the thin-pool's ondisk layout.

The following tables illustrate the realized gains/potential offered by
sorting each thin device's deferred_bio_list.  An "io size"-sized random
read of the device would result in "seeks/io" fragments being read, with
an average "distance/seek" between each fragment.

Data was written to a single thin device using multiple threads via
iozone (8 threads, 64K for both the block_size and io_size).

unsorted:

     io size   seeks/io distance/seek
  --------------------------------------
          4k    0.000   0b
         16k    0.013   11m
         64k    0.065   11m
        256k    0.274   10m
          1m    1.109   10m
          4m    4.411   10m
         16m    17.097  11m
         64m    60.055  13m
        256m    148.798 25m
          1g    809.929 21m

sorted:

     io size   seeks/io distance/seek
  --------------------------------------
          4k    0.000   0b
         16k    0.000   1g
         64k    0.001   1g
        256k    0.003   1g
          1m    0.011   1g
          4m    0.045   1g
         16m    0.181   1g
         64m    0.747   1011m
        256m    3.299   1g
          1g    14.373  1g

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-04-04 14:53:03 -04:00
Linus Torvalds
b33ce44299 Merge branch 'for-3.15/drivers' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "On top of the core pull request, here's the pull request for the
  driver related changes for 3.15.  It contains:

   - Improvements for msi-x registration for block drivers (mtip32xx,
     skd, cciss, nvme) from Alexander Gordeev.

   - A round of cleanups and improvements for drbd from Andreas
     Gruenbacher and Rashika Kheria.

   - A round of clanups and improvements for bcache from Kent.

   - Removal of sleep_on() and friends in DAC960, ataflop, swim3 from
     Arnd Bergmann.

   - Bug fix for a bug in the mtip32xx async completion code from Sam
     Bradshaw.

   - Bug fix for accidentally bouncing IO on 32-bit platforms with
     mtip32xx from Felipe Franciosi"

* 'for-3.15/drivers' of git://git.kernel.dk/linux-block: (103 commits)
  bcache: remove nested function usage
  bcache: Kill bucket->gc_gen
  bcache: Kill unused freelist
  bcache: Rework btree cache reserve handling
  bcache: Kill btree_io_wq
  bcache: btree locking rework
  bcache: Fix a race when freeing btree nodes
  bcache: Add a real GC_MARK_RECLAIMABLE
  bcache: Add bch_keylist_init_single()
  bcache: Improve priority_stats
  bcache: Better alloc tracepoints
  bcache: Kill dead cgroup code
  bcache: stop moving_gc marking buckets that can't be moved.
  bcache: Fix moving_pred()
  bcache: Fix moving_gc deadlocking with a foreground write
  bcache: Fix discard granularity
  bcache: Fix another bug recovering from unclean shutdown
  bcache: Fix a bug recovering from unclean shutdown
  bcache: Fix a journalling reclaim after recovery bug
  bcache: Fix a null ptr deref in journal replay
  ...
2014-04-01 19:43:53 -07:00
Linus Torvalds
675c354a95 Char/Misc driver patches for 3.15-rc1
Here's the big char/misc driver updates for 3.15-rc1.
 
 Lots of various things here, including the new mcb driver subsystem.
 
 All of these have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver patches from Greg KH:
 "Here's the big char/misc driver updates for 3.15-rc1.

  Lots of various things here, including the new mcb driver subsystem.

  All of these have been in linux-next for a while"

* tag 'char-misc-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (118 commits)
  extcon: Move OF helper function to extcon core and change function name
  extcon: of: Remove unnecessary function call by using the name of device_node
  extcon: gpio: Use SIMPLE_DEV_PM_OPS macro
  extcon: palmas: Use SIMPLE_DEV_PM_OPS macro
  mei: don't use deprecated DEFINE_PCI_DEVICE_TABLE macro
  mei: amthif: fix checkpatch error
  mei: client.h fix checkpatch errors
  mei: use cl_dbg where appropriate
  mei: fix Unnecessary space after function pointer name
  mei: report consistently copy_from/to_user failures
  mei: drop pr_fmt macros
  mei: make me hw headers private to me hw.
  mei: fix memory leak of pending write cb objects
  mei: me: do not reset when less than expected data is received
  drivers: mcb: Fix build error discovered by 0-day bot
  cs5535-mfgpt: Simplify dependencies
  spmi: pm: drop bus-level PM suspend/resume routines
  spmi: pmic_arb: make selectable on ARCH_QCOM
  Drivers: hv: vmbus: Increase the limit on the number of pfns we can handle
  pch_phub: Report error writing MAC back to user
  ...
2014-04-01 16:13:21 -07:00
Mike Snitzer
c140e1c4e2 dm thin: use per thin device deferred bio lists
The thin-pool previously only had a single deferred_bios list that would
collect bios for all thin devices in the pool.  Split this per-pool
deferred_bios list out to per-thin deferred_bios_list -- doing so
enables increased parallelism when processing deferred bios.  And now
that each thin device has it's own deferred_bios_list we can sort all
bios in the list using logical sector.  The requeue code in error
handling path is also cleaner as a side-effect.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-03-31 14:14:15 -04:00
Mike Snitzer
760fe67e53 dm thin: simplify pool_is_congested
The pool is congested if the pool is in PM_OUT_OF_DATA_SPACE mode.  This
is more explicit/clear/efficient than inferring whether or not the pool
is congested by checking if retry_on_resume_list is empty.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-03-31 10:05:51 -04:00
Mike Snitzer
fe76cd88e6 dm thin: fix dangling bio in process_deferred_bios error path
If unable to ensure_next_mapping() we must add the current bio, which
was removed from the @bios list via bio_list_pop, back to the
deferred_bios list before all the remaining @bios.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
2014-03-28 14:37:02 -04:00
Jose Castillo
a356e42620 dm mpath: print more useful warnings in multipath_message()
The warning message "Unrecognised multipath message received" is
displayed in two different situations in multipath_message(): when the
number of arguments passed is invalid and when the string passed in
argv[0] is not recognized.

Make it easier to identify where the problem is by making these warnings
more specific with additional context for each case.

Signed-off-by: Jose Castillo <jcastillo@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:25 -04:00
Hannes Reinecke
3a01750964 dm-mpath: do not activate failed paths
activate_path() is run without a lock, so the path might be
set to failed before activate_path() had a chance to run.
This patch add a check for ->active in activate_path() to
avoid unnecessary overhead by calling functions which are known
to be failing.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:25 -04:00
Mike Snitzer
9bf59a611a dm mpath: remove extra nesting in map function
Return early for case when no path exists, and when the
pathgroup isn't ready. This eliminates the need for
extra nesting for the the common case.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
2014-03-27 16:56:25 -04:00
Hannes Reinecke
36fcffcc65 dm mpath: remove map_io()
multipath_map() is now just a wrapper around map_io(), so we
can rename map_io() to multipath_map().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:25 -04:00
Hannes Reinecke
e3bde04f1e dm mpath: reduce memory pressure when requeuing
When multipath needs to requeue I/O in the block layer the per-request
context shouldn't be allocated, as it will be freed immediately
afterwards anyway.  Avoiding this memory allocation will reduce memory
pressure during requeuing.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:25 -04:00
Hannes Reinecke
3e9f1be1b4 dm mpath: remove process_queued_ios()
process_queued_ios() has served 3 functions:
  1) select pg and pgpath if none is selected
  2) start pg_init if requested
  3) dispatch queued IOs when pg is ready

Basically, a call to queue_work(process_queued_ios) can be replaced by
dm_table_run_md_queue_async(), which runs request queue and ends up
calling map_io(), which does 1), 2) and 3).

Exception is when !pg_ready() (which means either pg_init is running or
requested), then multipath_busy() prevents map_io() being called from
request_fn.

If pg_init is running, it should be ok as long as pg_init_done() does
the right thing when pg_init is completed, I.e.: restart pg_init if
!pg_ready() or call dm_table_run_md_queue_async() to kick map_io().

If pg_init is requested, we have to make sure the request is detected
and pg_init will be started.  pg_init is requested in 3 places:
  a) __choose_pgpath() in map_io()
  b) __choose_pgpath() in multipath_ioctl()
  c) pg_init retry in pg_init_done()
a) is ok because map_io() calls __pg_init_all_paths(), which does 2).
b) needs a call to __pg_init_all_paths(), which does 2).
c) needs a call to __pg_init_all_paths(), which does 2).

So this patch removes process_queued_ios() and ensures that
__pg_init_all_paths() is called at the appropriate locations.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:24 -04:00
Hannes Reinecke
e809917735 dm mpath: push back requests instead of queueing
There is no reason why multipath needs to queue requests internally for
queue_if_no_path or pg_init; we should rather push them back onto the
request queue.

And while we're at it we can simplify the conditional statement in
map_io() to make it easier to read.

Since mpath no longer does internal queuing of I/O the table info no
longer emits the internal queue_size.  Instead it displays 1 if queuing
is being used or 0 if it is not.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:24 -04:00
Mike Snitzer
9974fa2c6a dm table: add dm_table_run_md_queue_async
Introduce dm_table_run_md_queue_async() to run the request_queue of the
mapped_device associated with a request-based DM table.

Also add dm_md_get_queue() wrapper to extract the request_queue from a
mapped_device.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:24 -04:00
Hannes Reinecke
17f4ff45b5 dm mpath: do not call pg_init when it is already running
This patch moves condition checks as a preparation of following
patches and has no effect on behaviour.
process_queued_ios() is the only caller of __pg_init_all_paths()
and 2 condition checks are moved from outside to inside without
side effects.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
2014-03-27 16:56:24 -04:00
Monam Agarwal
9cdb852004 dm: use RCU_INIT_POINTER instead of rcu_assign_pointer in __unbind
Replace rcu_assign_pointer(p, NULL) with RCU_INIT_POINTER(p, NULL).

The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure.  And in the
case of the NULL pointer, there is no structure to initialize.  So,
rcu_assign_pointer(p, NULL) can be safely converted to
RCU_INIT_POINTER(p, NULL).

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:24 -04:00
Mikulas Patocka
bfc6d41cee dm: stop using bi_private
Device mapper uses the bio structure's bi_private field as a pointer
to dm_target_io or dm_rq_clone_bio_info.  But a bio structure is
embedded in the dm_target_io and dm_rq_clone_bio_info structures, so the
pointer to the structure that contains the bio can be found with the
container_of() macro.

Remove the use of bi_private and use container_of() instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:24 -04:00
Mikulas Patocka
d70ab4fb72 dm: remove dm_get_mapinfo
Remove dm_get_mapinfo() because no target uses it.  Targets can allocate
per-bio data using ti->per_bio_data_size, this is much more flexible
than union map_info.

Leave union map_info only for the request-based multipath target's use.
Also delete the unused "unsigned long long ll" field of union map_info.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:24 -04:00
Mikulas Patocka
473c36dfee dm: make dm_table_alloc_md_mempools static
Make the function dm_table_alloc_md_mempools static because it is not
called from another file.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:23 -04:00
Joe Thornber
5a32083d03 dm: take care to copy the space map roots before locking the superblock
In theory copying the space map root can fail, but in practice it never
does because we're careful to check what size buffer is needed.

But make certain we're able to copy the space map roots before
locking the superblock.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # drop dm-era and dm-cache changes as needed
2014-03-27 16:56:23 -04:00
Joe Thornber
a9d45396f5 dm transaction manager: fix corruption due to non-atomic transaction commit
The persistent-data library used by dm-thin, dm-cache, etc is
transactional.  If anything goes wrong, such as an io error when writing
new metadata or a power failure, then we roll back to the last
transaction.

Atomicity when committing a transaction is achieved by:

a) Never overwriting data from the previous transaction.
b) Writing the superblock last, after all other metadata has hit the
   disk.

This commit and the following commit ("dm: take care to copy the space
map roots before locking the superblock") fix a bug associated with (b).
When committing it was possible for the superblock to still be written
in spite of an io error occurring during the preceeding metadata flush.
With these commits we're careful not to take the write lock out on the
superblock until after the metadata flush has completed.

Change the transaction manager's semantics for dm_tm_commit() to assume
all data has been flushed _before_ the single superblock that is passed
in.

As a prerequisite, split the block manager's block unlocking and
flushing by simplifying dm_bm_flush_and_unlock() to dm_bm_flush().  Now
the unlocking must be done separately.

This issue was discovered by forcing io errors at the crucial time
using dm-flakey.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-03-27 16:56:23 -04:00
Heinz Mauelshagen
64ab346a36 dm cache: remove remainder of distinct discard block size
Discard block size not being equal to cache block size causes data
corruption by erroneously avoiding migrations in issue_copy() because
the discard state is being cleared for a group of cache blocks when it
should not.

Completely remove all code that enabled a distinction between the
cache block size and discard block size.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:23 -04:00
Mike Snitzer
d132cc6d9e dm cache: prevent corruption caused by discard_block_size > cache_block_size
If the discard block size is larger than the cache block size we will
not properly quiesce IO to a region that is about to be discarded.  This
results in a race between a cache migration where no copy is needed, and
a write to an adjacent cache block that's within the same large discard
block.

Workaround this by limiting the discard_block_size to cache_block_size.
Also limit the max_discard_sectors to cache_block_size.

A more comprehensive fix that introduces range locking support in the
bio_prison and proper quiescing of a discard range that spans multiple
cache blocks is already in development.

Reported-by: Morgan Mears <Morgan.Mears@netapp.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
Cc: stable@vger.kernel.org
2014-03-27 16:56:23 -04:00
Joe Thornber
428e469864 dm bitset: only flush the current word if it has been dirtied
This change offers a big performance boost for dm-era.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:23 -04:00
Joe Thornber
eec40579d8 dm: add era target
dm-era is a target that behaves similar to the linear target.  In
addition it keeps track of which blocks were written within a user
defined period of time called an 'era'.  Each era target instance
maintains the current era as a monotonically increasing 32-bit
counter.

Use cases include tracking changed blocks for backup software, and
partially invalidating the contents of a cache to restore cache
coherency after rolling back a vendor snapshot.

dm-era is primarily expected to be paired with the dm-cache target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-03-27 16:56:23 -04:00
John Sheu
cb85114956 bcache: remove nested function usage
Uninlined nested functions can cause crashes when using ftrace, as they don't
follow the normal calling convention and confuse the ftrace function graph
tracer as it examines the stack.

Also, nested functions are supported as a gcc extension, but may fail on other
compilers (e.g. llvm).

Signed-off-by: John Sheu <john.sheu@gmail.com>
2014-03-18 12:39:28 -07:00
Kent Overstreet
3a2fd9d509 bcache: Kill bucket->gc_gen
gc_gen was a temporary used to recalculate last_gc, but since we only need
bucket->last_gc when gc isn't running (gc_mark_valid = 1), we can just update
last_gc directly.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18 12:24:54 -07:00
Kent Overstreet
2531d9ee61 bcache: Kill unused freelist
This was originally added as at optimization that for various reasons isn't
needed anymore, but it does add a lot of nasty corner cases (and it was
responsible for some recently fixed bugs). Just get rid of it now.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18 12:23:36 -07:00