Commit Graph

3398 Commits

Author SHA1 Message Date
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