2898 Commits

Author SHA1 Message Date
Kent Overstreet
cc0f4eaa61 bcache: Use WARN_ONCE() instead of __WARN()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Geert Uytterhoeven
cd953ed036 bcache: Add missing #include <linux/prefetch.h>
m68k/allmodconfig:

drivers/md/bcache/bset.c: In function ‘bset_search_tree’:
drivers/md/bcache/bset.c:727: error: implicit declaration of function ‘prefetch’

drivers/md/bcache/btree.c: In function ‘bch_btree_node_get’:
drivers/md/bcache/btree.c:933: error: implicit declaration of function ‘prefetch’

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Kent Overstreet
c19ed23a0b bcache: Sparse fixes
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Mike Snitzer
19b0092e26 dm cache: reduce bio front_pad size in writeback mode
A recent patch to fix the dm cache target's writethrough mode extended
the bio's front_pad to include a 1056-byte struct dm_bio_details.
Writeback mode doesn't need this, so this patch reduces the
per_bio_data_size to 16 bytes in this case instead of 1096.

The dm_bio_details structure was added in "dm cache: fix writes to
cache device in writethrough mode" which fixed commit e2e74d617e ("dm
cache: fix race in writethrough implementation").  In writeback mode
we avoid allocating the writethrough-specific members of the
per_bio_data structure (the dm_bio_details structure included).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-04-05 15:36:34 +01:00
Darrick J. Wong
b844fe6918 dm cache: fix writes to cache device in writethrough mode
The dm-cache writethrough strategy introduced by commit e2e74d617eadc15
("dm cache: fix race in writethrough implementation") issues a bio to
the origin device, remaps and then issues the bio to the cache device.
This more conservative in-series approach was selected to favor
correctness over performance (of the previous parallel writethrough).
However, this in-series implementation that reuses the same bio to write
both the origin and cache device didn't take into account that the block
layer's req_bio_endio() modifies a completing bio's bi_sector and
bi_size.  So the new writethrough strategy needs to preserve these bio
fields, and restore them before submission to the cache device,
otherwise nothing gets written to the cache (because bi_size is 0).

This patch adds a struct dm_bio_details field to struct per_bio_data,
and uses dm_bio_record() and dm_bio_restore() to ensure the bio is
restored before reissuing to the cache device.  Adding such a large
structure to the per_bio_data is not ideal but we can improve this
later, for now correctness is the important thing.

This problem initially went unnoticed because the dm-cache test-suite
uses a linear DM device for the dm-cache device's origin device.
Writethrough worked as expected because DM submits a *clone* of the
original bio, so the original bio which was reused for the cache was
never touched.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-04-05 15:36:32 +01:00
Jens Axboe
64f8de4da7 Merge branch 'writeback-workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into for-3.10/core
Tejun writes:

-----

This is the pull request for the earlier patchset[1] with the same
name.  It's only three patches (the first one was committed to
workqueue tree) but the merge strategy is a bit involved due to the
dependencies.

* Because the conversion needs features from wq/for-3.10,
  block/for-3.10/core is based on rc3, and wq/for-3.10 has conflicts
  with rc3, I pulled mainline (rc5) into wq/for-3.10 to prevent those
  workqueue conflicts from flaring up in block tree.

* Resolving the issue that Jan and Dave raised about debugging
  requires arch-wide changes.  The patchset is being worked on[2] but
  it'll have to go through -mm after these changes show up in -next,
  and not included in this pull request.

The three commits are located in the following git branch.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git writeback-workqueue

Pulling it into block/for-3.10/core produces a conflict in
drivers/md/raid5.c between the following two commits.

  e3620a3ad5 ("MD RAID5: Avoid accessing gendisk or queue structs when not available")
  2f6db2a707 ("raid5: use bio_reset()")

The conflict is trivial - one removes an "if ()" conditional while the
other removes "rbi->bi_next = NULL" right above it.  We just need to
remove both.  The merged branch is available at

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git block-test-merge

so that you can use it for verification.  The test merge commit has
proper merge description.

While these changes are a bit of pain to route, they make code simpler
and even have, while minute, measureable performance gain[3] even on a
workload which isn't particularly favorable to showing the benefits of
this conversion.

----

Fixed up the conflict.

Conflicts:
	drivers/md/raid5.c

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-04-02 10:04:39 +02:00
Kent Overstreet
169ef1cf61 bcache: Don't export utility code, prefix with bch_
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-28 12:50:55 -06:00
Kent Overstreet
29177b8966 bcache: Fix for the build fixes
Commit 82a84eaf7e51ba3da0c36cbc401034a4e943492d left a return 0 in
closure_debug_init(). Whoops.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 19:36:39 -06:00
Kent Overstreet
b1a67b0f4c bcache: Style/checkpatch fixes
Took out some nested functions, and fixed some more checkpatch
complaints.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 13:06:13 -06:00
Kent Overstreet
07e86ccb54 bcache: Build fixes from test robot
config: make ARCH=i386 allmodconfig

All error/warnings:

   drivers/md/bcache/bset.c: In function 'bch_ptr_bad':
>> drivers/md/bcache/bset.c:164:2: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/debug.c: In function 'bch_pbtree':
>> drivers/md/bcache/debug.c:86:4: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/btree.c: In function 'bch_btree_read_done':
>> drivers/md/bcache/btree.c:245:8: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/closure.o: In function `closure_debug_init':
>> (.init.text+0x0): multiple definition of `init_module'
>> drivers/md/bcache/super.o:super.c:(.init.text+0x0): first defined here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 13:06:13 -06:00
Kent Overstreet
cafe563591 bcache: A block layer cache
Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.

See the wiki at http://bcache.evilpiepirate.org for more.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-03-23 16:11:31 -07:00
Linus Torvalds
22c3f2fff6 A few bugfixes for md
- recent regressions in raid5
  - recent regressions in dmraid
  - a few instances of CONFIG_MULTICORE_RAID456 linger
 
 Several tagged for -stable
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Merge tag 'md-3.9-fixes' of git://neil.brown.name/md

Pull md fixes from NeilBrown:
 "A few bugfixes for md

   - recent regressions in raid5
   - recent regressions in dmraid
   - a few instances of CONFIG_MULTICORE_RAID456 linger

  Several tagged for -stable"

* tag 'md-3.9-fixes' of git://neil.brown.name/md:
  md: remove CONFIG_MULTICORE_RAID456 entirely
  md/raid5: ensure sync and DISCARD don't happen at the same time.
  MD: Prevent sysfs operations on uninitialized kobjects
  MD RAID5: Avoid accessing gendisk or queue structs when not available
  md/raid5: schedule_construction should abort if nothing to do.
2013-03-23 15:49:49 -07:00
Kent Overstreet
a07876064a block: Add bio_alloc_pages()
More utility code to replace stuff that's getting open coded.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:26:31 -07:00
Kent Overstreet
cb34e057ad block: Convert some code to bio_for_each_segment_all()
More prep work for immutable bvecs:

A few places in the code were either open coding or using the wrong
version - fix.

After we introduce the bvec iter, it'll no longer be possible to modify
the biovec through bio_for_each_segment_all() - it doesn't increment a
pointer to the current bvec, you pass in a struct bio_vec (not a
pointer) which is updated with what the current biovec would be (taking
into account bi_bvec_done and bi_size).

So because of that it's more worthwhile to be consistent about
bio_for_each_segment()/bio_for_each_segment_all() usage.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Alexander Viro <viro@zeniv.linux.org.uk>
2013-03-23 14:26:30 -07:00
Kent Overstreet
d74c6d514f block: Add bio_for_each_segment_all()
__bio_for_each_segment() iterates bvecs from the specified index
instead of bio->bv_idx.  Currently, the only usage is to walk all the
bvecs after the bio has been advanced by specifying 0 index.

For immutable bvecs, we need to split these apart;
bio_for_each_segment() is going to have a different implementation.
This will also help document the intent of code that's using it -
bio_for_each_segment_all() is only legal to use for code that owns the
bio.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Neil Brown <neilb@suse.de>
CC: Boaz Harrosh <bharrosh@panasas.com>
2013-03-23 14:26:28 -07:00
Kent Overstreet
d3b45c2a05 raid1: use bio_copy_data()
This doesn't really delete any code _yet_, but once immutable bvecs are
done we can just delete the rest of the code in that loop.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:38 -07:00
Kent Overstreet
b783863f68 raid1: Refactor narrow_write_error() to not use bi_idx
More bi_idx removal. This code was just open coding bio_clone(). This
could probably be further improved by using bio_advance() instead of
skipping over null pages, but that'd be a larger rework.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:36 -07:00
Kent Overstreet
2f6db2a707 raid5: use bio_reset()
Had to shuffle the code around a bit (where bi_rw and bi_end_io were
set), but shouldn't really be anything tricky here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:35 -07:00
Kent Overstreet
2aabaa65ad raid1: use bio_reset()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:34 -07:00
Kent Overstreet
8be185f2c9 raid10: Use bio_reset()
More prep work for immutable bio vecs, mainly getting rid of references
to bi_idx.

bio_reset was being open coded in a few places. The one in sync_request
was a bit nontrivial to convert, so could use some extra eyeballs.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>
2013-03-23 14:15:33 -07:00
Kent Overstreet
9e882242c6 block: Add submit_bio_wait(), remove from md
Random cleanup - this code was duplicated and it's not really specific
to md.

Also added the ability to return the actual error code.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
2013-03-23 14:15:32 -07:00
Kent Overstreet
4f2ac93c17 block: Remove bi_idx references
For immutable bvecs, all bi_idx usage needs to be audited - so here
we're removing all the unnecessary uses.

Most of these are places where it was being initialized on a bio that
was just allocated, a few others are conversions to standard macros.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
2013-03-23 14:15:31 -07:00
Kent Overstreet
5b83636ae3 block: Change bio_split() to respect the current value of bi_idx
In the current code bio_split() won't be seeing partially completed bios
so this doesn't change any behaviour, but this makes the code a bit
clearer as to what bio_split() actually requires.

The immediate purpose of the patch is removing unnecessary bi_idx
references, but the end goal is to allow partial completed bios to be
submitted, which along with immutable biovecs enables effecient bio
splitting.

Some of the callers were (double) checking that bios could be split, so
update their checks too.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Neil Brown <neilb@suse.de>
CC: Martin K. Petersen <martin.petersen@oracle.com>
2013-03-23 14:15:30 -07:00
Kent Overstreet
aa8b57aa3d block: Use bio_sectors() more consistently
Bunch of places in the code weren't using it where they could be -
this'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx
into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: "Ed L. Cashin" <ecashin@coraid.com>
CC: Nick Piggin <npiggin@kernel.dk>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Jim Paris <jim@jtan.com>
CC: Geoff Levand <geoff@infradead.org>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ed Cashin <ecashin@coraid.com>
2013-03-23 14:15:30 -07:00
Kent Overstreet
f73a1c7d11 block: Add bio_end_sector()
Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
CC: Chris Mason <chris.mason@fusionio.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2013-03-23 14:15:29 -07:00
Kent Overstreet
fb9e353476 md: Convert md_trim_bio() to use bio_advance()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>
2013-03-23 14:15:28 -07:00
Mike Snitzer
ea2dd8c1ed dm cache: policy ignore hints if generated by different version
When reading the dm cache metadata from disk, ignore the policy hints
unless they were generated by the same major version number of the same
policy module.

The hints are considered to be private data belonging to the specific
module that generated them and there is no requirement for them to make
sense to different versions of the policy that generated them.
Policy modules are all required to work fine if no previous hints are
supplied (or if existing hints are lost).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:28 +00:00
Mike Snitzer
4e7f506f64 dm cache: policy change version from string to integer set
Separate dm cache policy version string into 3 unsigned numbers
corresponding to major, minor and patchlevel and store them at the end
of the on-disk metadata so we know which version of the policy generated
the hints in case a future version wants to use them differently.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Joe Thornber
e2e74d617e dm cache: fix race in writethrough implementation
We have found a race in the optimisation used in the dm cache
writethrough implementation.  Currently, dm core sends the cache target
two bios, one for the origin device and one for the cache device and
these are processed in parallel.  This patch avoids the race by
changing the code back to a simpler (slower) implementation which
processes the two writes in series, one after the other, until we can
develop a complete fix for the problem.

When the cache is in writethrough mode it needs to send WRITE bios to
both the origin and cache devices.

Previously we've been implementing this by having dm core query the
cache target on every write to find out how many copies of the bio it
wants.  The cache will ask for two bios if the block is in the cache,
and one otherwise.

Then main problem with this is it's racey.  At the time this check is
made the bio hasn't yet been submitted and so isn't being taken into
account when quiescing a block for migration (promotion or demotion).
This means a single bio may be submitted when two were needed because
the block has since been promoted to the cache (catastrophic), or two
bios where only one is needed (harmless).

I really don't want to start entering bios into the quiescing system
(deferred_set) in the get_num_write_bios callback.  Instead this patch
simplifies things; only one bio is submitted by the core, this is
first written to the origin and then the cache device in series.
Obviously this will have a latency impact.

deferred_writethrough_bios is introduced to record bios that must be
later issued to the cache device from the worker thread.  This deferred
submission, after the origin bio completes, is required given that we're
in interrupt context (writethrough_endio).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Joe Thornber
79ed9caffc dm cache: metadata clear dirty bits on clean shutdown
When writing the dirty bitset to the metadata device on a clean
shutdown, clear the dirty bits.  Previously they were left indicating
the cache was dirty. This led to confusion about whether there really
was dirty data in the cache or not.  (This was a harmless bug.)

Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Heinz Mauelshagen
b978440b8d dm cache: avoid calling policy destructor twice on error
If the cache policy's config values are not able to be set we must
set the policy to NULL after destroying it in create_cache_policy()
so we don't attempt to destroy it a second time later.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:26 +00:00
Heinz Mauelshagen
617a0b89da dm cache: detect cache_create failure
Return error if cache_create() fails.

A missing return check made cache_ctr continue even after an error in
cache_create() resulting in the cache object being destroyed.  So a
simple failure like an odd number of cache policy config value arguments
would result in an oops.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:26 +00:00
Joe Thornber
414dd67d50 dm cache: avoid 64 bit division on 32 bit
Squash various 32bit link errors.

  >> on i386:
  >> drivers/built-in.o: In function `is_discarded_oblock':
  >> dm-cache-target.c:(.text+0x1ea28e): undefined reference to `__udivdi3'
  ...

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:25 +00:00
Mikulas Patocka
3b6b7813b1 dm verity: avoid deadlock
A deadlock was found in the prefetch code in the dm verity map
function.  This patch fixes this by transferring the prefetch
to a worker thread and skipping it completely if kmalloc fails.

If generic_make_request is called recursively, it queues the I/O
request on the current->bio_list without making the I/O request
and returns. The routine making the recursive call cannot wait
for the I/O to complete.

The deadlock occurs when one thread grabs the bufio_client
mutex and waits for an I/O to complete but the I/O is queued
on another thread's current->bio_list and is waiting to get
the mutex held by the first thread.

The fix recognises that prefetching is not essential.  If memory
can be allocated, it queues the prefetch request to the worker thread,
but if not, it does nothing.

Signed-off-by: Paul Taysom <taysom@chromium.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2013-03-20 17:21:25 +00:00
Joe Thornber
58051b94e0 dm thin: fix non power of two discard granularity calc
Fix a discard granularity calculation to work for non power of 2 block sizes.

In order for thinp to passdown discard bios to the underlying data
device, the data device must have a discard granularity that is a
factor of the thinp block size.  Originally this check was done by
using bitops since the block_size was known to be a power of two.

Introduced by commit f13945d75730081830b6f3360266950e2b7c9067
("dm thin: support a non power of 2 discard_granularity").

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:25 +00:00
Joe Thornber
f046f89a99 dm thin: fix discard corruption
Fix a bug in dm_btree_remove that could leave leaf values with incorrect
reference counts.  The effect of this was that removal of a shared block
could result in the space maps thinking the block was no longer used.
More concretely, if you have a thin device and a snapshot of it, sending
a discard to a shared region of the thin could corrupt the snapshot.

Thinp uses a 2-level nested btree to store it's mappings.  This first
level is indexed by thin device, and the second level by logical
block.

Often when we're removing an entry in this mapping tree we need to
rebalance nodes, which can involve shadowing them, possibly creating a
copy if the block is shared.  If we do create a copy then children of
that node need to have their reference counts incremented.  In this
way reference counts percolate down the tree as shared trees diverge.

The rebalance functions were incrementing the children at the
appropriate time, but they were always assuming the children were
internal nodes.  This meant the leaf values (in our case packed
block/flags entries) were not being incremented.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:24 +00:00
Paul Bolle
238f5908bd md: remove CONFIG_MULTICORE_RAID456 entirely
Once instance of this Kconfig macro remained after commit
51acbcec6c42b24482bac18e42befc822524535d ("md: remove
CONFIG_MULTICORE_RAID456"). Remove that one too. And, while we're at it,
also remove it from the defconfig files that carry it.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:21:14 +11:00
NeilBrown
f8dfcffd04 md/raid5: ensure sync and DISCARD don't happen at the same time.
A number of problems can occur due to races between
resync/recovery and discard.

- if sync_request calls handle_stripe() while a discard is
  happening on the stripe, it might call handle_stripe_clean_event
  before all of the individual discard requests have completed
  (so some devices are still locked, but not all).
  Since commit ca64cae96037de16e4af92678814f5d4bf0c1c65
     md/raid5: Make sure we clear R5_Discard when discard is finished.
  this will cause R5_Discard to be cleared for the parity device,
  so handle_stripe_clean_event() will not be called when the other
  devices do become unlocked, so their ->written will not be cleared.
  This ultimately leads to a WARN_ON in init_stripe and a lock-up.

- If handle_stripe_clean_event() does clear R5_UPTODATE at an awkward
  time for resync, it can lead to s->uptodate being less than disks
  in handle_parity_checks5(), which triggers a BUG (because it is
  one).

So:
 - keep R5_Discard on the parity device until all other devices have
   completed their discard request
 - make sure we don't try to have a 'discard' and a 'sync' action at
   the same time.
   This involves a new stripe flag to we know when a 'discard' is
   happening, and the use of R5_Overlap on the parity disk so when a
   discard is wanted while a sync is active, so we know to wake up
   the discard at the appropriate time.

Discard support for RAID5 was added in 3.7, so this is suitable for
any -stable kernel since 3.7.

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Tested-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:20:59 +11:00
Jonathan Brassow
90584fc93d MD: Prevent sysfs operations on uninitialized kobjects
MD: Prevent sysfs operations on uninitialized kobjects

Device-mapper does not use sysfs; but when device-mapper is leveraging
MD's RAID personalities, MD sometimes attempts to update sysfs.  This
patch adds checks for 'mddev-kobj.sd' in sysfs_[un]link_rdev to ensure
it is about to operate on something valid.  This patch also checks for
'mddev->kobj.sd' before calling 'sysfs_notify' in 'remove_and_add_spares'.
Although 'sysfs_notify' already makes this check, doing so in
'remove_and_add_spares' prevents an additional mutex operation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:17:57 +11:00
Jonathan Brassow
e3620a3ad5 MD RAID5: Avoid accessing gendisk or queue structs when not available
MD RAID5:  Fix kernel oops when RAID4/5/6 is used via device-mapper

Commit a9add5d (v3.8-rc1) added blktrace calls to the RAID4/5/6 driver.
However, when device-mapper is used to create RAID4/5/6 arrays, the
mddev->gendisk and mddev->queue fields are not setup.  Therefore, calling
things like trace_block_bio_remap will cause a kernel oops.  This patch
conditionalizes those calls on whether the proper fields exist to make
the calls.  (Device-mapper will call trace_block_bio_remap on its own.)

This patch is suitable for the 3.8.y stable kernel.

Cc: stable@vger.kernel.org (v3.8+)
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:16:57 +11:00
NeilBrown
ce7d363aaf md/raid5: schedule_construction should abort if nothing to do.
Since commit 1ed850f356a0a422013846b5291acff08815008b
    md/raid5: make sure to_read and to_write never go negative.

It has been possible for handle_stripe_dirtying to be called
when there isn't actually any work to do.
It then calls schedule_reconstruction() which will set R5_LOCKED
on the parity block(s) even when nothing else is happening.
This then causes problems in do_release_stripe().

So add checks to schedule_reconstruction() so that if it doesn't
find anything to do, it just aborts.

This bug was introduced in v3.7, so the patch is suitable
for -stable kernels since then.

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 12:16:51 +11:00
Linus Torvalds
a5e0d73163 md updates for 3.9
mostly little bugfixes.
 Only "feature" is a new RAID10 layout which slightly
 improves the number of sets of devices that can concurrently
 fail, without data loss.
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Merge tag 'md-3.9' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 "Mostly little bugfixes.

  Only "feature" is a new RAID10 layout which slightly improves the
  number of sets of devices that can concurrently fail, without data
  loss."

* tag 'md-3.9' of git://neil.brown.name/md:
  md: expedite metadata update when switching  read-auto -> active
  md: remove CONFIG_MULTICORE_RAID456
  md/raid1,raid10: fix deadlock with freeze_array()
  md/raid0: improve error message when converting RAID4-with-spares to RAID0
  md: raid0: fix error return from create_stripe_zones.
  md: fix two bugs when attempting to resize RAID0 array.
  DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2)
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)
  MD RAID10: Minor non-functional code changes
  md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
  md: protect against crash upon fsync on ro array
2013-03-05 17:22:08 -08:00
Heinz Mauelshagen
8735a81347 dm cache: add cleaner policy
A simple cache policy that writes back all data to the origin.

This is used to decommission a dm cache by emptying it.

Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:52 +00:00
Joe Thornber
f283635281 dm cache: add mq policy
A cache policy that uses a multiqueue ordered by recent hit
count to select which blocks should be promoted and demoted.
This is meant to be a general purpose policy.  It prioritises
reads over writes.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
c6b4fcbad0 dm: add cache target
Add a target that allows a fast device such as an SSD to be used as a
cache for a slower device such as a disk.

A plug-in architecture was chosen so that the decisions about which data
to migrate and when are delegated to interchangeable tunable policy
modules.  The first general purpose module we have developed, called
"mq" (multiqueue), follows in the next patch.  Other modules are
under development.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
7a87edfee7 dm persistent data: add bitset
Add a persistent bitset as a wrapper around dm-array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
6513c29f44 dm persistent data: add transactional array
Add a transactional array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
025b96853f dm thin: remove cells from stack
This patch takes advantage of the new bio-prison interface where the
memory is now passed in rather than using a mempool in bio-prison.
This allows the map function to avoid performing potentially-blocking
allocations that could lead to deadlocks: We want to avoid the cell
allocation that is done in bio_detain.

(The potential for mempool deadlocks still remains in other functions
that use bio_detain.)

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Joe Thornber
6beca5eb6e dm bio prison: pass cell memory in
Change the dm_bio_prison interface so that instead of allocating memory
internally, dm_bio_detain is supplied with a pre-allocated cell each
time it is called.

This enables a subsequent patch to move the allocation of the struct
dm_bio_prison_cell outside the thin target's mapping function so it can
no longer block there.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Joe Thornber
4e7f1f9089 dm persistent data: add btree_walk
Add dm_btree_walk to iterate through the contents of a btree.
This will be used by the dm cache target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00