If you prepare_to_wait() after a previous prepare_to_wait(),
but before calling schedule(), you get warning:
do not call blocking ops when !TASK_RUNNING; state=2
This is appropriate as it is often a bug. The event that the
first prepare_to_wait() expects might wake up the schedule following
the second prepare_to_wait(), which could be confusing.
However if both prepare_to_wait()s are part of simple wait_event()
loops, and if the inner one is rarely called, then there is
no problem. The inner loop is too simple to get confused by
a stray wakeup, and the outer loop won't spin unduly because the
inner doesnt affect it often.
This pattern occurs in both raid1.c and raid10.c in the use of
flush_pending_writes().
The warning can be silenced by setting current->state to TASK_RUNNING.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
There are some lines could be removed due to recent
change for raid1 such as commit 3956df15d634 ("md:
move suspend_hi/lo handling into core md code").
Also, seems some comments are put to wrong place,
move them before wait_barrier.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
If freeze_array is attempted in the middle of close_sync/
wait_all_barriers, deadlock can occur.
freeze_array will wait for nr_pending and nr_queued to line up.
wait_all_barriers increments nr_pending for each barrier bucket, one
at a time, but doesn't actually issue IO that could be counted in
nr_queued. So freeze_array is blocked until wait_all_barriers
completes and allow_all_barriers runs. At the same time, when
_wait_barrier sees array_frozen == 1, it stops and waits for
freeze_array to complete.
Prevent the deadlock by making close_sync call _wait_barrier and
_allow_barrier for one bucket at a time, instead of deferring the
_allow_barrier calls until after all _wait_barriers are complete.
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Fix: fd76863e37fe(RAID1: a new I/O barrier implementation to remove resync window)
Reviewed-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org (v4.11)
Signed-off-by: Shaohua Li <shli@fb.com>
Hi - I submit this patch for the next merge window:
Some times ago, I made a patch f9c79bc05a that blocks signals around the
schedule() calls in MD. The MD subsystem needs to do an uninterruptible
sleep that is not accounted in load average - so we block signals and use
interruptible sleep.
The kernel has a special TASK_IDLE state for this purpose, so we can use
it instead of blocking signals. This patch doesn't fix any bug, it just
makes the code simpler.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
responding to ->suspend_lo and ->suspend_hi is similar
to responding to ->suspended. It is best to wait in
the common core code without incrementing ->active_io.
This allows mddev_suspend()/mddev_resume() to work while
requests are waiting for suspend_lo/hi to change.
This is will be important after a subsequent patch
which uses mddev_suspend() to synchronize updating for
suspend_lo/hi.
So move the code for testing suspend_lo/hi out of raid1.c
and raid5.c, and place it in md.c
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
The check used here is to avoid conflict between write and
resync, however we used the wrong logic, it should be the
inverse of the checking inside "if".
Fixes: 589a1c4 ("Suspend writes in RAID1 if within range")
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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
Increase PPL area to 1MB and use it as circular buffer to store PPL. The
entry with highest generation number is the latest one. If PPL to be
written is larger then space left in a buffer, rewind the buffer to the
start (don't wrap it).
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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>
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>
After bio is submitted, we should not clone it as its bi_iter might be
invalid by driver. This is the case of behind_master_bio. In certain
situration, we could dispatch behind_master_bio immediately for the
first disk and then clone it for other disks.
https://bugzilla.kernel.org/show_bug.cgi?id=196383
Reported-and-tested-by: Markus <m4rkusxxl@web.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Fix: 841c1316c7da(md: raid1: improve write behind)
Cc: stable@vger.kernel.org (4.12+)
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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>
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>
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()
"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>
The "bio" is not used in sync_request_write after commit a68e587035
("md/raid1: split out two sub-functions from sync_request_write").
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The function flush_signals clears all pending signals for the process. It
may be used by kernel threads when we need to prepare a kernel thread for
responding to signals. However using this function for an userspaces
processes is incorrect - clearing signals without the program expecting it
can cause misbehavior.
The raid1 and raid5 code uses flush_signals in its request routine because
it wants to prepare for an interruptible wait. This patch drops
flush_signals and uses sigprocmask instead to block all signals (including
SIGKILL) around the schedule() call. The signals are not lost, but the
schedule() call won't respond to them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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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>
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>
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>
If an array consists of two drives and the first drive has the bad
block, the read request to the region overlapping the bad block chooses
the same disk (with bad block) as device to read from over and over and
the request gets stuck. If the first disk only partially overlaps with
bad block, it becomes a candidate ("best disk") for shorter range of
sectors. The second disk is capable of reading the entire requested
range and it is updated accordingly, however it is not recorded as a
best device for the request. In the end the request is sent to the first
disk to read entire range of sectors. It fails and is re-tried in a
moment but with the same outcome.
Actually it is quite likely scenario but it had little exposure in my
test until commit 715d40b93b10 ("md/raid1: add failfast handling for
reads.") removed preference for idle disk. Such scenario had been
passing as second disk was always chosen when idle.
Reset a candidate ("best disk") to read from if disk can read entire
range. Do it only if other disk has already been chosen as a candidate
for a smaller range. The head position / disk type logic will select
the best disk to read from - it is fine as disk with bad block won't be
considered for it.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
This essentially reverts commit b5470dc5fc ("md: resolve external
metadata handling deadlock in md_allow_write") with some adjustments.
Since commit 6791875e2e ("md: make reconfig_mutex optional for writes
to md sysfs files.") changing array_state to 'active' does not use
mddev_lock() and will not cause a deadlock with md_allow_write(). This
revert simplifies userspace tools that write to sysfs attributes like
"stripe_cache_size" or "consistency_policy" because it removes the need
for special handling for external metadata arrays, checking for EAGAIN
and retrying the write.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
In new barrier codes, raise_barrier waits if conf->nr_pending[idx] is not zero.
After all the conditions are true, the resync request can go on be handled. But
it adds conf->nr_pending[idx] again. The next resync request hit the same bucket
idx need to wait the resync request which is submitted before. The performance
of resync/recovery is degraded.
So we should use a new variable to count sync requests which are in flight.
I did a simple test:
1. Without the patch, create a raid1 with two disks. The resync speed:
Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdb 0.00 0.00 166.00 0.00 10.38 0.00 128.00 0.03 0.20 0.20 0.00 0.19 3.20
sdc 0.00 0.00 0.00 166.00 0.00 10.38 128.00 0.96 5.77 0.00 5.77 5.75 95.50
2. With the patch, the result is:
sdb 2214.00 0.00 766.00 0.00 185.69 0.00 496.46 2.80 3.66 3.66 0.00 1.03 79.10
sdc 0.00 2205.00 0.00 769.00 0.00 186.44 496.52 5.25 6.84 0.00 6.84 1.30 100.10
Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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>
flush_pending_writes() and raid1_unplug() each contain identical
copies of a fairly large slab of code. So factor that out into
new flush_bio_list() to simplify maintenance.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
handle_read_error() duplicates a lot of the work that raid1_read_request()
does, so it makes sense to just use that function.
This doesn't quite work as handle_read_error() relies on the same r1bio
being re-used so that, in the case of a read-only array, setting
IO_BLOCKED in r1bio->bios[] ensures read_balance() won't re-use
that device.
So we need to allow a r1bio to be passed to raid1_read_request(), and to
have that function mostly initialise the r1bio, but leave the bios[]
array untouched.
Two parts of handle_read_error() that need to be preserved are the warning
message it prints, so they are conditionally added to raid1_read_request().
Note that this highlights a minor bug on alloc_r1bio(). It doesn't
initalise the bios[] array, so it is possible that old content is there,
which might cause read_balance() to ignore some devices with no good reason.
With this change, we no longer need inc_pending(), or the sectors_handled
arg to alloc_r1bio().
As handle_read_error() is called from raid1d() and allocates memory,
there is tiny chance of a deadlock. All element of various pools
could be queued waiting for raid1 to handle them, and there may be no
extra memory free.
Achieving guaranteed forward progress would probably require a second
thread and another mempool. Instead of that complexity, add
__GFP_HIGH to any allocations when read1_read_request() is called
from raid1d.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Now that we always always pass an offset of 0 and a size
that matches the bio to alloc_behind_master_bio(),
we can remove the offset/size args and simplify the code.
We could probably remove bio_copy_data_partial() too.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
raid1 currently splits requests in two different ways for
two different reasons.
First, bio_split() is used to ensure the bio fits within a
resync accounting region.
Second, multiple r1bios are allocated for each bio to handle
the possiblity of known bad blocks on some devices.
This can be simplified to just use bio_split() once, and not
use multiple r1bios.
We delay the split until we know a maximum bio size that can
be handled with a single r1bio, and then split the bio and
queue the remainder for later handling.
This avoids all loops inside raid1.c request handling. Just
a single read, or a single set of writes, is submitted to
lower-level devices for each bio that comes from
generic_make_request().
When the bio needs to be split, generic_make_request() will
do the necessary looping and call md_make_request() multiple
times.
raid1_make_request() no longer queues request for raid1 to handle,
so we can remove that branch from the 'if'.
This patch also creates a new private bio_set
(conf->bio_split) for splitting bios. Using fs_bio_set
is wrong, as it is meant to be used by filesystems, not
block devices. Using it inside md can lead to deadlocks
under high memory pressure.
Delete unused variable in raid1_write_request() (Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
fix_sync_read_error() modifies a bio on a newly faulty
device by setting bi_end_io to end_sync_write.
This ensure that put_buf() will still call rdev_dec_pending()
as required, but makes sure that subsequent code in
fix_sync_read_error() doesn't try to read from the device.
Unfortunately this interacts badly with sync_request_write()
which assumes that any bio with bi_end_io set to non-NULL
other than end_sync_read is safe to write to.
As the device is now faulty it doesn't make sense to write.
As the bio was recently used for a read, it is "dirty"
and not suitable for immediate submission.
In particular, ->bi_next might be non-NULL, which will cause
generic_make_request() to complain.
Break this interaction by refusing to write to devices
which are marked as Faulty.
Reported-and-tested-by: Michael Wang <yun.wang@profitbricks.com>
Fixes: 2e52d449bc ("md/raid1: add failfast handling for reads.")
Cc: stable@vger.kernel.org (v4.10+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
This patch kills the warning reported on powerpc_pseries,
and actually we don't need the initialization.
After merging the md tree, today's linux-next build (powerpc
pseries_le_defconfig) produced this warning:
drivers/md/raid1.c: In function 'raid1d':
drivers/md/raid1.c:2172:9: warning: 'page_len$' may be used uninitialized in this function [-Wmaybe-uninitialized]
if (memcmp(page_address(ppages[j]),
^
drivers/md/raid1.c:2160:7: note: 'page_len$' was declared here
int page_len[RESYNC_PAGES];
^
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
discard request doesn't have data attached, so it's meaningless to
allocate memory and copy from original bio for behind IO. And the copy
is bogus because bio_copy_data_partial can't handle discard request.
We don't support writesame/writezeros request so far.
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This patch improve handling of write behind in the following ways:
- introduce behind master bio to hold all write behind pages
- fast clone bios from behind master bio
- avoid to change bvec table directly
- use bio_copy_data() and make code more clean
Suggested-by: Shaohua Li <shli@fb.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The 'offset' local variable can't be changed inside the loop, so
move it out.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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) * raid_disks
bytes per r1_bio, and it is fine because the inflight r1_bio for
resync shouldn't be much, as pointed by Shaohua.
Also the bio_reset() in raid1_sync_request() is removed because
all bios are freshly new now and not necessary to reset any more.
This patch can be thought as a 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>
This patch gets each page's reference of each bio for resync,
then r1buf_pool_free() gets simplified a lot.
The same policy has been taken in raid10's buf pool allocation/free
too.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
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>
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>
Change to use bio->__bi_remaining to count number of r1bio attached
to a bio.
See precious raid10 patch for more details.
Like the raid10.c patch, this fixes a bug as nr_queued and nr_pending
used to measure different things, but were being compared.
This patch fixes another bug in that nr_pending previously did not
could write-behind requests, so behind writes could continue while
resync was happening. How that nr_pending counts all r1_bio,
the resync cannot commence until the behind writes have completed.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
