Commit Graph

428 Commits

Author SHA1 Message Date
Shaohua Li
18022a1bd3 md/raid1/10: add missed blk plug
flush_pending_writes isn't always called with block plug, so add it, and plug
works in nested way.

Signed-off-by: Shaohua Li <shli@fb.com>
2017-12-01 12:19:48 -08:00
Guoqing Jiang
8db87912c9 md-cluster: Use a small window for raid10 resync
Suspending the entire device for resync could take
too long. Resync in small chunks.

cluster's resync window is maintained in r10conf as
cluster_sync_low and cluster_sync_high, and processed
in raid10's sync_request(). If the current resync is
outside the cluster resync window:

1. Set the cluster_sync_low to curr_resync_completed.
2. Set cluster_sync_high to cluster_sync_low + stripe
   size.
3. Send a message to all nodes so they may add it in
   their suspension list.

Note:
We only support "near" raid10 so far, resync a far or
offset raid10 array could have trouble. So raid10_run
checks the layout of clustered raid10, it will refuse
to run if the layout is not correct.

With the "near" layout we process one stripe at a time
progressing monotonically through the address space.
So we can have a sliding window of whole-stripes which
moves through the array suspending IO on other nodes,
and both resync which uses array addresses and recovery
which uses device addresses can stay within this window.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01 21:32:23 -07:00
Guoqing Jiang
cb8a7a7e10 md-cluster: Suspend writes in RAID10 if within range
If there is a resync going on, all nodes must suspend
writes to the range. This is recorded in suspend_info
and suspend_list.

If there is an I/O within the ranges of any of the
suspend_info, area_resyncing will return 1.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01 21:32:23 -07:00
Guoqing Jiang
d4098c7262 md-cluster/raid10: set "do_balance = 0" if area is resyncing
Just like clustered raid1, it is impossible for cluster raid10
to choose the best device for read balance when the area of
array is resyncing. Because we cannot trust the data to be the
same on all devices at that time, so we choose just the first
one to use, so set do_balance to 0.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01 21:32:22 -07:00
NeilBrown
b03e0ccb5a md: remove special meaning of ->quiesce(.., 2)
The '2' argument means "wake up anything that is waiting".
This is an inelegant part of the design and was added
to help support management of suspend_lo/suspend_hi setting.
Now that suspend_lo/hi is managed in mddev_suspend/resume,
that need is gone.
These is still a couple of places where we call 'quiesce'
with an argument of '2', but they can safely be changed to
call ->quiesce(.., 1); ->quiesce(.., 0) which
achieve the same result at the small cost of pausing IO
briefly.

This removes a small "optimization" from suspend_{hi,lo}_store,
but it isn't clear that optimization served a useful purpose.
The code now is a lot clearer.

Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-11-01 21:32:20 -07:00
Colin Ian King
a0e764c543 md: raid10: remove a couple of redundant variables and initializations
Variables dev and bio_last_sector are assigned values that are never
read and hence these are redundant variables and can be removed.
Also remove the duplicated initialization of sectors, the latter
assignment is identical to the first and can be removed.

Cleans up 3 clang build warnings:
Value stored to 'dev' is never read
Value stored to 'bio_last_sector' is never read
Value stored to 'sectors' during its initialization is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-10-16 19:06:37 -07:00
Mike Snitzer
935fe0983e md: rename some drivers/md/ files to have an "md-" prefix
Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list.  Which is born out of the fact that DM files also
reside in drivers/md/

Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.

Shaohua: don't change module name

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-10-16 19:06:36 -07:00
Matthias Kaehlcke
584ed9fa95 md: raid10: remove VLAIS
The raid10 driver can't be built with clang since it uses a variable
length array in a structure (VLAIS):

drivers/md/raid10.c:4583:17: error: fields must have a constant size:
  'variable length array in structure' extension will never be supported

Allocate the r10bio struct with kmalloc instead of using the VLAIS
construct.

Shaohua: set the MD_RECOVERY_INTR bit
Neil Brown: use GFP_NOIO

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-10-16 19:06:35 -07:00
Linus Torvalds
3645e6d0dc Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD updates from Shaohua Li:
 "This update mainly fixes bugs:

   - Make raid5 ppl support several ppl from Pawel

   - Several raid5-cache bug fixes from Song

   - Bitmap fixes from Neil and Me

   - One raid1/10 regression fix since 4.12 from Me

   - Other small fixes and cleanup"

* tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/bitmap: disable bitmap_resize for file-backed bitmaps.
  raid5-ppl: Recovery support for multiple partial parity logs
  md: Runtime support for multiple ppls
  md/raid0: attach correct cgroup info in bio
  lib/raid6: align AVX512 constants to 512 bits, not bytes
  raid5: remove raid5_build_block
  md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_show
  md: replace seq_release_private with seq_release
  md: notify about new spare disk in the container
  md/raid1/10: reset bio allocated from mempool
  md/raid5: release/flush io in raid5_do_work()
  md/bitmap: copy correct data for bitmap super
2017-09-07 12:41:48 -07:00
Shaohua Li
208410b546 md/raid1/10: reset bio allocated from mempool
Data allocated from mempool doesn't always get initialized, this happens when
the data is reused instead of fresh allocation. In the raid1/10 case, we must
reinitialize the bios.

Reported-by: Jonathan G. Underwood <jonathan.underwood@gmail.com>
Fixes: f0250618361d(md: raid10: don't use bio's vec table to manage resync pages)
Fixes: 98d30c5812c3(md: raid1: don't use bio's vec table to manage resync pages)
Cc: stable@vger.kernel.org (4.12+)
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-08-25 10:21:44 -07:00
Christoph Hellwig
74d46992e0 block: replace bi_bdev with a gendisk pointer and partitions index
This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:55 -06:00
Guoqing Jiang
6308d8e3d4 md: simplify code with bio_io_error
Since bio_io_error sets bi_status to BLK_STS_IOERR,
and calls bio_endio, so we can use it directly.

And as mentioned by Shaohua, there are also two
places in raid5.c can use bio_io_error either.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-07-21 13:16:52 -07:00
Ming Lei
be453e7761 md: raid1-10: move raid1/raid10 common code into raid1-10.c
No function change, just move 'struct resync_pages' and related
helpers into raid1-10.c

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-07-21 12:47:20 -07:00
Ming Lei
fb0eb5df09 md: raid1/raid10: initialize bvec table via bio_add_page()
We will support multipage bvec soon, so initialize bvec
table using the standardy way instead of writing the
talbe directly. Otherwise it won't work any more once
multipage bvec is enabled.

Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-07-21 12:47:20 -07:00
Ming Lei
022e510fcb md: remove 'idx' from 'struct resync_pages'
bio_add_page() won't fail for resync bio, and the page index for each
bio is same, so remove it.

More importantly the 'idx' of 'struct resync_pages' is initialized in
mempool allocator function, the current way is wrong since mempool is
only responsible for allocation, we can't use that for initialization.

Suggested-by: NeilBrown <neilb@suse.com>
Reported-by: NeilBrown <neilb@suse.com>
Reported-and-tested-by: Patrick <dto@gmx.net>
Fixes: f0250618361d(md: raid10: don't use bio's vec table to manage resync pages)
Fixes: 98d30c5812c3(md: raid1: don't use bio's vec table to manage resync pages)
Cc: stable@vger.kernel.org (4.12+)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-07-21 12:47:20 -07:00
Linus Torvalds
026d15f6b9 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD update from Shaohua Li:

 - fixed deadlock in MD suspend and a potential bug in bio allocation
   (Neil Brown)

 - fixed signal issue (Mikulas Patocka)

 - fixed typo in FailFast test (Guoqing Jiang)

 - other trival fixes

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  MD: fix sleep in atomic
  MD: fix a null dereference
  md: use a separate bio_set for synchronous IO.
  md: change the initialization value for a spare device spot to MD_DISK_ROLE_SPARE
  md/raid1: remove unused bio in sync_request_write
  md/raid10: fix FailFast test for wrong device
  md: don't use flush_signals in userspace processes
  md: fix deadlock between mddev_suspend() and md_write_start()
2017-07-08 12:50:18 -07:00
NeilBrown
011067b056 blk: replace bioset_create_nobvec() with a flags arg to bioset_create()
"flags" arguments are often seen as good API design as they allow
easy extensibility.
bioset_create_nobvec() is implemented internally as a variation in
flags passed to __bioset_create().

To support future extension, make the internal structure part of the
API.
i.e. add a 'flags' argument to bioset_create() and discard
bioset_create_nobvec().

Note that the bio_split allocations in drivers/md/raid* do not need
the bvec mempool - they should have used bioset_create_nobvec().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 12:40:59 -06:00
Guoqing Jiang
1cdd125794 md/raid10: fix FailFast test for wrong device
We need to test FailFast flag for replacement device here
since the set up for writing is for the replacement, so we
need fix it like:

- if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
+ if (test_bit(FailFast, &conf->mirrors[d].replacement->flags))

Since commit f90145f317 ("md/raid10: add rcu protection
to rdev access in raid10_sync_request.") had added the rcu
protection for the part, so let's extend the range protected
by rcu and use rdev directly.

Fixes: 1919cbb ("md/raid10: add failfast handling for writes.")
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-06-16 12:04:08 -07:00
NeilBrown
cc27b0c78c md: fix deadlock between mddev_suspend() and md_write_start()
If mddev_suspend() races with md_write_start() we can deadlock
with mddev_suspend() waiting for the request that is currently
in md_write_start() to complete the ->make_request() call,
and md_write_start() waiting for the metadata to be updated
to mark the array as 'dirty'.
As metadata updates done by md_check_recovery() only happen then
the mddev_lock() can be claimed, and as mddev_suspend() is often
called with the lock held, these threads wait indefinitely for each
other.

We fix this by having md_write_start() abort if mddev_suspend()
is happening, and ->make_request() aborts if md_write_start()
aborted.
md_make_request() can detect this abort, decrease the ->active_io
count, and wait for mddev_suspend().

Reported-by: Nix <nix@esperi.org.uk>
Fix: 68866e425be2(MD: no sync IO while suspended)
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-06-13 10:18:01 -07:00
Jens Axboe
8f66439eec Linux 4.12-rc5
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Merge tag 'v4.12-rc5' into for-4.13/block

We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.

Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-12 08:30:13 -06:00
Christoph Hellwig
4e4cbee93d block: switch bios to blk_status_t
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
NeilBrown
a415c0f106 md: initialise ->writes_pending in personality modules.
The new per-cpu counter for writes_pending is initialised in
md_alloc(), which is not called by dm-raid.
So dm-raid fails when md_write_start() is called.

Move the initialization to the personality modules
that need it.  This way it is always initialised when needed,
but isn't unnecessarily initialized (requiring memory allocation)
when the personality doesn't use writes_pending.

Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Fixes: 4ad23a9764 ("MD: use per-cpu counter for writes_pending")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-06-05 16:04:35 -07:00
Shaohua Li
23b245c04d md/raid1/10: avoid unnecessary locking
If we add bios to block plugging list, locking is unnecessry, since the block
unplug is guaranteed not to run at that time.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-05-11 15:32:17 -07:00
Shaohua Li
e265eb3a30 Merge branch 'md-next' into md-linus 2017-05-01 14:09:21 -07:00
Shaohua Li
b506335e5d md/raid10: skip spare disk as 'first' disk
Commit 6f287ca(md/raid10: reset the 'first' at the end of loop) ignores
a case in reshape, the first rdev could be a spare disk, which shouldn't
be accounted as the first disk since it doesn't include the offset info.

Fix: 6f287ca(md/raid10: reset the 'first' at the end of loop)
Cc: Guoqing Jiang <gqjiang@suse.com>
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-05-01 12:24:10 -07:00
Guoqing Jiang
e5bc9c3c54 md: clear WantReplacement once disk is removed
We can clear 'WantReplacement' flag directly no
matter it's replacement existed or not since the
semantic is same as before.

Also since the disk is removed from array, then
it is straightforward to remove 'WantReplacement'
flag and the comments in raid10/5 can be removed
as well.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-25 09:36:29 -07:00
Lidong Zhong
296617581e md/raid1/10: remove unused queue
A queue is declared and get from the disk of the array, but it's not
used anywhere. So removing it from the source.

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Acted-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-23 16:59:13 -07:00
Guoqing Jiang
cf25ae78fc md/raid10: wait up frozen array in handle_write_completed
Since nr_queued is changed, we need to call wake_up here
if the array is already frozen and waiting for condition
"nr_pending == nr_queued + extra" to be true.

And commit 824e47dadd ("RAID1: avoid unnecessary spin
locks in I/O barrier code") which has already added the
wake_up for raid1.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-20 09:55:52 -07:00
NeilBrown
545250f248 md/raid10: simplify handle_read_error()
handle_read_error() duplicates a lot of the work that raid10_read_request()
does, so it makes sense to just use that function.

handle_read_error() relies on the same r10bio being re-used so that,
in the case of a read-only array, setting IO_BLOCKED in r1bio->devs[].bio
ensures read_balance() won't re-use that device.
So when called from raid10_make_request() we clear that array, but not
when called from handle_read_error().

Two parts of handle_read_error() that need to be preserved are the warning
message it prints, so they are conditionally added to
raid10_read_request().  If the failing rdev can be found, messages
are printed.  Otherwise they aren't.

Not that as rdev_dec_pending() has already been called on the failing
rdev, we need to use rcu_read_lock() to get a new reference from
the conf.  We only use this to get the name of the failing block device.

With this change, we no longer need inc_pending().

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-11 10:15:08 -07:00
NeilBrown
fc9977dd06 md/raid10: simplify the splitting of requests.
raid10 splits requests in two different ways for two different
reasons.

First, bio_split() is used to ensure the bio fits with a chunk.
Second, multiple r10bio structures are allocated to represent the
different sections that need to go to different devices, to avoid
known bad blocks.

This can be simplified to just use bio_split() once, and not to use
multiple r10bios.
We delay the split until we know a maximum bio size that can
be handled with a single r10bio, and then split the bio and queue
the remainder for later handling.

As with raid1, we allocate a new bio_set to help with the splitting.
It is not correct to use fs_bio_set in a device driver.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-11 10:13:02 -07:00
Guoqing Jiang
6f287ca604 md/raid10: reset the 'first' at the end of loop
We need to set "first = 0' at the end of rdev_for_each
loop, so we can get the array's min_offset_diff correctly
otherwise min_offset_diff just means the last rdev's
offset diff.

Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-04-10 10:41:50 -07:00
Christoph Hellwig
3deff1a70d md: support REQ_OP_WRITE_ZEROES
Copy & paste from the REQ_OP_WRITE_SAME code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08 11:25:38 -06:00
Ming Lei
2d06e3b714 md: raid10: avoid direct access to bvec table in handle_reshape_read_error
All reshape I/O share pages from 1st copy device, so just use that pages
for avoiding direct access to bvec table in handle_reshape_read_error.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:37 -07:00
Ming Lei
cdb76be315 md: raid10: retrieve page from preallocated resync page array
Now one page array is allocated for each resync bio, and we can
retrieve page from this table directly.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:37 -07:00
Ming Lei
f025061836 md: raid10: don't use bio's vec table to manage resync pages
Now we allocate one page array for managing resync pages, instead
of using bio's vec table to do that, and the old way is very hacky
and won't work any more if multipage bvec is enabled.

The introduced cost is that we need to allocate (128 + 16) * copies
bytes per r10_bio, and it is fine because the inflight r10_bio for
resync shouldn't be much, as pointed by Shaohua.

Also bio_reset() in raid10_sync_request() and reshape_request()
are removed because all bios are freshly new now in these functions
and not necessary to reset any more.

This patch can be thought as cleanup too.

Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:37 -07:00
Ming Lei
81fa152008 md: raid10: refactor code of read reshape's .bi_end_io
reshape read request is a bit special and requires one extra
bio which isn't allocated from r10buf_pool.

Refactor the .bi_end_io for read reshape, so that we can use
raid10's resync page mangement approach easily in the following
patches.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:37 -07:00
Ming Lei
d8e29fbc3b md: move two macros into md.h
Both raid1 and raid10 share common resync
block size and page count, so move them into md.h.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:36 -07:00
Ming Lei
c85ba149de md: raid1/raid10: don't handle failure of bio_add_page()
All bio_add_page() is for adding one page into resync bio,
which is big enough to hold RESYNC_PAGES pages, and
the current bio_add_page() doesn't check queue limit any more,
so it won't fail at all.

remove unused label (shaohua)

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-24 10:41:36 -07:00
Guoqing Jiang
27f26a0f37 md/raid10: refactor some codes from raid10_write_request
Previously, we clone both bio and repl_bio in raid10_write_request,
then add the cloned bio to plug->pending or conf->pending_bio_list
based on plug or not, and most of the logics are same for the two
conditions.

So introduce raid10_write_one_disk for it, and use replacement parameter
to distinguish the difference. No functional changes in the patch.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-23 22:42:14 -07:00
NeilBrown
fd16f2e848 md/raid10: stop using bi_phys_segments
raid10 currently repurposes bi_phys_segments on each
incoming bio to count how many r10bio was used to encode the
request.

We need to know when the number of attached r10bio reaches
zero to:
1/ call bio_endio() when all IO on the bio is finished
2/ decrement ->nr_pending so that resync IO can proceed.

Now that the bio has its own __bi_remaining counter, that
can be used instead. We can call bio_inc_remaining to
increment the counter and call bio_endio() every time an
r10bio completes, rather than only when bi_phys_segments
reaches zero.

This addresses point 1, but not point 2.  bio_endio()
doesn't (and cannot) report when the last r10bio has
finished, so a different approach is needed.

So: instead of counting bios in ->nr_pending, count r10bios.
i.e. every time we attach a bio, increment nr_pending.
Every time an r10bio completes, decrement nr_pending.

Normally we only increment nr_pending after first checking
that ->barrier is zero, or some other non-trivial tests and
possible waiting.  When attaching multiple r10bios to a bio,
we only need the tests and the waiting once.  After the
first increment, subsequent increments can happen
unconditionally as they are really all part of the one
request.

So introduce inc_pending() which can be used when we know
that nr_pending is already elevated.

Note that this fixes a bug.  freeze_array() contains the line
	atomic_read(&conf->nr_pending) == conf->nr_queued+extra,
which implies that the units for ->nr_pending, ->nr_queued and extra
are the same.
->nr_queue and extra count r10_bios, but prior to this patch,
->nr_pending counted bios.  If a bio ever resulted in multiple
r10_bios (due to bad blocks), freeze_array() would not work correctly.
Now it does.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-22 19:17:41 -07:00
NeilBrown
6b6c8110e1 md/raid1, raid10: move rXbio accounting closer to allocation.
When raid1 or raid10 find they will need to allocate a new
r1bio/r10bio, in order to work around a known bad block, they
account for the allocation well before the allocation is
made.  This separation makes the correctness less obvious
and requires comments.

The accounting needs to be a little before: before the first
rXbio is submitted, but that is all.

So move the accounting down to where it makes more sense.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-22 19:17:24 -07:00
Linus Torvalds
3009b303b0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD fixes from Shaohua Li:

 - fix a parity calculation bug of raid5 cache by Song

 - fix a potential deadlock issue by me

 - fix two endian issues by Jason

 - fix a disk limitation issue by Neil

 - other small fixes and cleanup

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid1: fix a trivial typo in comments
  md/r5cache: fix set_syndrome_sources() for data in cache
  md: fix incorrect use of lexx_to_cpu in does_sb_need_changing
  md: fix super_offset endianness in super_1_rdev_size_change
  md/raid1/10: fix potential deadlock
  md: don't impose the MD_SB_DISKS limit on arrays without metadata.
  md: move funcs from pers->resize to update_size
  md-cluster: remove useless memset from gather_all_resync_info
  md-cluster: free md_cluster_info if node leave cluster
  md: delete dead code
  md/raid10: submit bio directly to replacement disk
2017-03-16 11:43:48 -07:00
NeilBrown
f5fe1b5190 blk: Ensure users for current->bio_list can see the full list.
Commit 79bd99596b ("blk: improve order of bio handling in generic_make_request()")
changed current->bio_list so that it did not contain *all* of the
queued bios, but only those submitted by the currently running
make_request_fn.

There are two places which walk the list and requeue selected bios,
and others that check if the list is empty.  These are no longer
correct.

So redefine current->bio_list to point to an array of two lists, which
contain all queued bios, and adjust various code to test or walk both
lists.

Signed-off-by: NeilBrown <neilb@suse.com>
Fixes: 79bd99596b ("blk: improve order of bio handling in generic_make_request()")
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-11 15:31:37 -07:00
Shaohua Li
61eb2b43b9 md/raid1/10: fix potential deadlock
Neil Brown pointed out a potential deadlock in raid 10 code with
bio_split/chain. The raid1 code could have the same issue, but recent
barrier rework makes it less likely to happen. The deadlock happens in
below sequence:

1. generic_make_request(bio), this will set current->bio_list
2. raid10_make_request will split bio to bio1 and bio2
3. __make_request(bio1), wait_barrer, add underlayer disk bio to
current->bio_list
4. __make_request(bio2), wait_barrer

If raise_barrier happens between 3 & 4, since wait_barrier runs at 3,
raise_barrier waits for IO completion from 3. And since raise_barrier
sets barrier, 4 waits for raise_barrier. But IO from 3 can't be
dispatched because raid10_make_request() doesn't finished yet.

The solution is to adjust the IO ordering. Quotes from Neil:
"
It is much safer to:

    if (need to split) {
        split = bio_split(bio, ...)
        bio_chain(...)
        make_request_fn(split);
        generic_make_request(bio);
   } else
        make_request_fn(mddev, bio);

This way we first process the initial section of the bio (in 'split')
which will queue some requests to the underlying devices.  These
requests will be queued in generic_make_request.
Then we queue the remainder of the bio, which will be added to the end
of the generic_make_request queue.
Then we return.
generic_make_request() will pop the lower-level device requests off the
queue and handle them first.  Then it will process the remainder
of the original bio once the first section has been fully processed.
"

Note, this only happens in read path. In write path, the bio is flushed to
underlaying disks either by blk flush (from schedule) or offladed to raid1/10d.
It's queued in current->bio_list.

Cc: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org (v3.14+, only the raid10 part)
Suggested-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-09 09:02:42 -08:00
Guoqing Jiang
c948363421 md: move funcs from pers->resize to update_size
raid1_resize and raid5_resize should also check the
mddev->queue if run underneath dm-raid.

And both set_capacity and revalidate_disk are used in
pers->resize such as raid1, raid10 and raid5. So
move them from personality file to common code.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-09 09:02:18 -08:00
Shaohua Li
6d399783e9 md/raid10: submit bio directly to replacement disk
Commit 57c67df(md/raid10: submit IO from originating thread instead of
md thread) submits bio directly for normal disks but not for replacement
disks. There is no point we shouldn't do this for replacement disks.

Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-03-09 09:01:14 -08:00
Linus Torvalds
a682e00354 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull md updates from Shaohua Li:
 "Mainly fixes bugs and improves performance:

   - Improve scalability for raid1 from Coly

   - Improve raid5-cache read performance, disk efficiency and IO
     pattern from Song and me

   - Fix a race condition of disk hotplug for linear from Coly

   - A few cleanup patches from Ming and Byungchul

   - Fix a memory leak from Neil

   - Fix WRITE SAME IO failure from me

   - Add doc for raid5-cache from me"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (23 commits)
  md/raid1: fix write behind issues introduced by bio_clone_bioset_partial
  md/raid1: handle flush request correctly
  md/linear: shutup lockdep warnning
  md/raid1: fix a use-after-free bug
  RAID1: avoid unnecessary spin locks in I/O barrier code
  RAID1: a new I/O barrier implementation to remove resync window
  md/raid5: Don't reinvent the wheel but use existing llist API
  md: fast clone bio in bio_clone_mddev()
  md: remove unnecessary check on mddev
  md/raid1: use bio_clone_bioset_partial() in case of write behind
  md: fail if mddev->bio_set can't be created
  block: introduce bio_clone_bioset_partial()
  md: disable WRITE SAME if it fails in underlayer disks
  md/raid5-cache: exclude reclaiming stripes in reclaim check
  md/raid5-cache: stripe reclaim only counts valid stripes
  MD: add doc for raid5-cache
  Documentation: move MD related doc into a separate dir
  md: ensure md devices are freed before module is unloaded.
  md/r5cache: improve journal device efficiency
  md/r5cache: enable chunk_aligned_read with write back cache
  ...
2017-02-24 14:42:19 -08:00
Ming Lei
d7a1030839 md: fast clone bio in bio_clone_mddev()
Firstly bio_clone_mddev() is used in raid normal I/O and isn't
in resync I/O path.

Secondly all the direct access to bvec table in raid happens on
resync I/O except for write behind of raid1, in which we still
use bio_clone() for allocating new bvec table.

So this patch replaces bio_clone() with bio_clone_fast()
in bio_clone_mddev().

Also kill bio_clone_mddev() and call bio_clone_fast() directly, as
suggested by Christoph Hellwig.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-02-15 11:24:54 -08:00
Jan Kara
dc3b17cc8b block: Use pointer to backing_dev_info from request_queue
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:20:48 -07:00
Robert LeBlanc
bb5f1ed70b md/raid10: Refactor raid10_make_request
Refactor raid10_make_request into seperate read and write functions to
clean up the code.

Shaohua: add the recovery check back to read path

Signed-off-by: Robert LeBlanc <robert@leblancnet.us>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-01-03 08:56:52 -08:00