Commit 7e55c60acf ("md/raid5: Pivot raid5_make_request()") changed the
order in which requests for underlying disks are created. Since for
large sequential IO adding of requests frequently races with md_raid5
thread submitting bios to underlying disks, this results in a change in
IO pattern because intermediate states of new order of request creation
result in more smaller discontiguous requests. For RAID5 on top of three
rotational disks our performance testing revealed this results in
regression in write throughput:
iozone -a -s 131072000 -y 4 -q 8 -i 0 -i 1 -R
before 7e55c60acf:
KB reclen write rewrite read reread
131072000 4 493670 525964 524575 513384
131072000 8 540467 532880 512028 513703
after 7e55c60acf:
KB reclen write rewrite read reread
131072000 4 421785 456184 531278 509248
131072000 8 459283 456354 528449 543834
To reduce the amount of discontiguous requests we can start generating
requests with the stripe with the lowest chunk offset as that has the
best chance of being adjacent to IO queued previously. This improves the
performance to:
KB reclen write rewrite read reread
131072000 4 497682 506317 518043 514559
131072000 8 514048 501886 506453 504319
restoring big part of the regression.
Fixes: 7e55c60acf ("md/raid5: Pivot raid5_make_request()")
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230417171537.17899-1-jack@suse.cz
clang with W=1 reports
drivers/md/raid5.c:7719:6: error: variable 'working_disks'
set but not used [-Werror,-Wunused-but-set-variable]
int working_disks = 0;
^
This variable is not used so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230327132324.1769595-1-trix@redhat.com
A complicated deadlock exists when using the journal and an elevated
group_thrtead_cnt. It was found with loop devices, but its not clear
whether it can be seen with real disks. The deadlock can occur simply
by writing data with an fio script.
When the deadlock occurs, multiple threads will hang in different ways:
1) The group threads will hang in the blk-wbt code with bios waiting to
be submitted to the block layer:
io_schedule+0x70/0xb0
rq_qos_wait+0x153/0x210
wbt_wait+0x115/0x1b0
io_schedule+0x70/0xb0
rq_qos_wait+0x153/0x210
wbt_wait+0x115/0x1b0
__rq_qos_throttle+0x38/0x60
blk_mq_submit_bio+0x589/0xcd0
wbt_wait+0x115/0x1b0
__rq_qos_throttle+0x38/0x60
blk_mq_submit_bio+0x589/0xcd0
__submit_bio+0xe6/0x100
submit_bio_noacct_nocheck+0x42e/0x470
submit_bio_noacct+0x4c2/0xbb0
ops_run_io+0x46b/0x1a30
handle_stripe+0xcd3/0x36b0
handle_active_stripes.constprop.0+0x6f6/0xa60
raid5_do_work+0x177/0x330
Or:
io_schedule+0x70/0xb0
rq_qos_wait+0x153/0x210
wbt_wait+0x115/0x1b0
__rq_qos_throttle+0x38/0x60
blk_mq_submit_bio+0x589/0xcd0
__submit_bio+0xe6/0x100
submit_bio_noacct_nocheck+0x42e/0x470
submit_bio_noacct+0x4c2/0xbb0
flush_deferred_bios+0x136/0x170
raid5_do_work+0x262/0x330
2) The r5l_reclaim thread will hang in the same way, submitting a
bio to the block layer:
io_schedule+0x70/0xb0
rq_qos_wait+0x153/0x210
wbt_wait+0x115/0x1b0
__rq_qos_throttle+0x38/0x60
blk_mq_submit_bio+0x589/0xcd0
__submit_bio+0xe6/0x100
submit_bio_noacct_nocheck+0x42e/0x470
submit_bio_noacct+0x4c2/0xbb0
submit_bio+0x3f/0xf0
md_super_write+0x12f/0x1b0
md_update_sb.part.0+0x7c6/0xff0
md_update_sb+0x30/0x60
r5l_do_reclaim+0x4f9/0x5e0
r5l_reclaim_thread+0x69/0x30b
However, before hanging, the MD_SB_CHANGE_PENDING flag will be
set for sb_flags in r5l_write_super_and_discard_space(). This
flag will never be cleared because the submit_bio() call never
returns.
3) Due to the MD_SB_CHANGE_PENDING flag being set, handle_stripe()
will do no processing on any pending stripes and re-set
STRIPE_HANDLE. This will cause the raid5d thread to enter an
infinite loop, constantly trying to handle the same stripes
stuck in the queue.
The raid5d thread has a blk_plug that holds a number of bios
that are also stuck waiting seeing the thread is in a loop
that never schedules. These bios have been accounted for by
blk-wbt thus preventing the other threads above from
continuing when they try to submit bios. --Deadlock.
To fix this, add the same wait_event() that is used in raid5_do_work()
to raid5d() such that if MD_SB_CHANGE_PENDING is set, the thread will
schedule and wait until the flag is cleared. The schedule action will
flush the plug which will allow the r5l_reclaim thread to continue,
thus preventing the deadlock.
However, md_check_recovery() calls can also clear MD_SB_CHANGE_PENDING
from the same thread and can thus deadlock if the thread is put to
sleep. So avoid waiting if md_check_recovery() is being called in the
loop.
It's not clear when the deadlock was introduced, but the similar
wait_event() call in raid5_do_work() was added in 2017 by this
commit:
16d997b78b ("md/raid5: simplfy delaying of writes while metadata
is updated.")
Link: https://lore.kernel.org/r/7f3b87b6-b52a-f737-51d7-a4eec5c44112@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
When running chunk-sized reads on disks with badblocks duplicate bio
free/puts are observed:
=============================================================================
BUG bio-200 (Not tainted): Object already free
-----------------------------------------------------------------------------
Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504
__slab_alloc.constprop.0+0x5a/0xb0
kmem_cache_alloc+0x31e/0x330
mempool_alloc_slab+0x17/0x20
mempool_alloc+0x100/0x2b0
bio_alloc_bioset+0x181/0x460
do_mpage_readpage+0x776/0xd00
mpage_readahead+0x166/0x320
blkdev_readahead+0x15/0x20
read_pages+0x13f/0x5f0
page_cache_ra_unbounded+0x18d/0x220
force_page_cache_ra+0x181/0x1c0
page_cache_sync_ra+0x65/0xb0
filemap_get_pages+0x1df/0xaf0
filemap_read+0x1e1/0x700
blkdev_read_iter+0x1e5/0x330
vfs_read+0x42a/0x570
Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504
kmem_cache_free+0x46d/0x490
mempool_free_slab+0x17/0x20
mempool_free+0x66/0x190
bio_free+0x78/0x90
bio_put+0x100/0x1a0
raid5_make_request+0x2259/0x2450
md_handle_request+0x402/0x600
md_submit_bio+0xd9/0x120
__submit_bio+0x11f/0x1b0
submit_bio_noacct_nocheck+0x204/0x480
submit_bio_noacct+0x32e/0xc70
submit_bio+0x98/0x1a0
mpage_readahead+0x250/0x320
blkdev_readahead+0x15/0x20
read_pages+0x13f/0x5f0
page_cache_ra_unbounded+0x18d/0x220
Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff)
CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: raid5wq raid5_do_work
Call Trace:
<TASK>
dump_stack_lvl+0x5a/0x78
dump_stack+0x10/0x16
print_trailer+0x158/0x165
object_err+0x35/0x50
free_debug_processing.cold+0xb7/0xbe
__slab_free+0x1ae/0x330
kmem_cache_free+0x46d/0x490
mempool_free_slab+0x17/0x20
mempool_free+0x66/0x190
bio_free+0x78/0x90
bio_put+0x100/0x1a0
mpage_end_io+0x36/0x150
bio_endio+0x2fd/0x360
md_end_io_acct+0x7e/0x90
bio_endio+0x2fd/0x360
handle_failed_stripe+0x960/0xb80
handle_stripe+0x1348/0x3760
handle_active_stripes.constprop.0+0x72a/0xaf0
raid5_do_work+0x177/0x330
process_one_work+0x616/0xb20
worker_thread+0x2bd/0x6f0
kthread+0x179/0x1b0
ret_from_fork+0x22/0x30
</TASK>
The double free is caused by an unnecessary bio_put() in the
if(is_badblock(...)) error path in raid5_read_one_chunk().
The error path was moved ahead of bio_alloc_clone() in c82aa1b767
("md/raid5: move checking badblock before clone bio in
raid5_read_one_chunk"). The previous code checked and freed align_bio
which required a bio_put. After the move that is no longer needed as
raid_bio is returned to the control of the common io path which
performs its own endio resulting in a double free on bad device blocks.
Fixes: c82aa1b767 ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk")
Signed-off-by: David Sloan <david.sloan@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guoqing Jiang <Guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
When doing degrade/recover tests using the journal a kernel BUG
is hit at drivers/md/raid5.c:4381 in handle_parity_checks5():
BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
This was found to occur because handle_stripe_fill() was skipped
for stripes in the journal due to a condition in that function.
Thus blocks were not fetched and R5_UPTODATE was not set when
the code reached handle_parity_checks5().
To fix this, don't skip handle_stripe_fill() unless the stripe is
for read.
Fixes: 07e8336484 ("md/r5cache: shift complex rmw from read path to write path")
Link: https://lore.kernel.org/linux-raid/e05c4239-41a9-d2f7-3cfa-4aa9d2cea8c1@deltatee.com/
Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
The atomic_read() is not needed in many cases so only do
the read after the first checks are done.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Drop the three bools in the prototype of raid5_get_active_stripe()
and replace them with a flags parameter.
At the same time, drop the distinction with __raid5_get_active_stripe().
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Refactor raid5_get_active_stripe() without the gotos with an
explicit infinite loop and some additional nesting.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve latency
and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and
may cause sh to be released. However, sh is subsequently used in lines
2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an
use-after-free bug.
It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of
the function.
Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A race condition exists where if raid5_quiesce() is called in the
middle of a request that has set batch_last, it will deadlock.
batch_last will hold a reference to a stripe when raid5_quiesce() is
called. This will cause the next raid5_get_active_stripe() call to
sleep waiting for the quiesce to finish, but the raid5_quiesce() thread
will wait for active_stripes to go to zero which will never happen
because request thread is waiting for the quiesce to stop.
Fix this by creating a special __raid5_get_active_stripe() function
which takes the request context and clears the last_batch before
sleeping.
While we're at it, change the arguments of raid5_get_active_stripe()
to bools.
Fixes: 3312e6c887 ("md/raid5: Keep a reference to last stripe_head for batch")
Reported-by: David Sloan <David.Sloan@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move stripe_request_ctx up. No functional changes intended.
This will be necessary in the next patch to release the batch_last
in the context before sleeping.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that raid5_get_active_stripe() has been refactored it is appearant
that r5c_check_stripe_cache_usage() doesn't need to be called in
the wait_for_stripe branch.
r5c_check_stripe_cache_usage() will only conditionally call
r5l_wake_reclaim(), but that function is called two lines later.
Drop the call for cleanup.
Reported-by: Martin Oliveira <martin.oliveira@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The logic to wait_for_stripe is difficult to parse being on so many
lines and with confusing operator precedence. Move it to a helper
function to make it easier to read.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refactor the raid5_get_active_stripe() to read more linearly in
the order it's typically executed.
The init_stripe() call is called if a free stripe is found and the
function is exited early which removes a lot of if (sh) checks and
unindents the following code.
Remove the while loop in favour of the 'goto retry' pattern, which
reduces indentation further. And use a 'goto wait_for_stripe' instead
of an additional indent seeing it is the unusual path and this makes
the code easier to read.
No functional changes intended. Will make subsequent changes
in patches easier to understand.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
'first' will always be greater than or equal to 0, it is unnecessary to
repeat the 0 check, clean it up.
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
raid5_get_active_stripe() can sleep in various situations and it
is called by make_stripe_request() while inside the
prepare_to_wait()/finish_wait() section. Nested waits like this are
not supported.
This was noticed while making other changes that add different sleeps
to raid5_get_active_stripe() that caused a WARNING with
CONFIG_DEBUG_ATOMIC_SLEEP.
No ill effects have been noticed with the code as is, but theoretically
a nested and here could cause a dead lock so it should be fixed.
To fix this, convert the prepare_to_wait() call to use wake_woken()
which supports nested sleeps.
Link: https://lwn.net/Articles/628628/
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For unaligned IO that have nearly maximum sectors, the number of stripes
will end up being one greater than the size of the bitmap. When this
happens, the last stripe in the IO will not be processed as it should
be, resulting in data corruption.
However, this is not normally seen when the backing block devices have
4K physical block sizes since the block layer will split the request
before that happens.
To fix this increase the bitmap size by one bit and ensure the full
number of stripes are checked when calling find_first_bit().
Reported-by: David Sloan <David.Sloan@eideticom.com>
Fixes: 7e55c60acf ("md/raid5: Pivot raid5_make_request()")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The block layer defaults the maximum segments to 128, which means
requests tend to get split around the 512KB depending on how many
pages can be merged. There's no such restriction in the raid5 code
so increase the limit to USHRT_MAX so that larger requests can be
sent as one.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a debug print for raid5_make_request() so that each request is
printed and add the logical sector number to the debug print in
__add_stripe_bio().
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
raid5_make_request() loops through every page in the request,
finds the appropriate stripe and adds the bio for that page in the
disk.
This causes a great deal of contention on the hash_lock and extra
work seeing each stripe must be found once for every data disk.
The number of times a stripe must be found can be reduced by pivoting
raid5_make_request() so that it loops through every stripe and then
loops through every disk in that stripe to see if the bio must be
added. This reduces the number of times the hash lock must be taken
by a factor equal to the number of data disks.
To accomplish this, the logical sectors that have already been added
must be tracked. Tracking them is done with a bitmap: the bits
for all pages are set at the start of the request and each bit
is cleared once the bio is added to a stripe.
Finding the next sector to be done is then just a call to
find_first_bit() so that sectors that have been done can simply be
skipped.
One minor downside is that the maximum sectors for a request must be
limited so that the bitmap can be appropriately sized on the stack.
This limit is arbitrarily chosen to be 256 stripe pages which works out
to 1MB if PAGE_SIZE == DEFAULT_STRIPE_SIZE. This doesn't actually
restrict the maximum request further seeing the default block queue
settings are used which restricts the number of segments to 128 (which
results in request sizes that are approximately 512KB).
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When testing if a previous stripe has had reshape expand past it, use
the earliest or latest logical sector in all the disks for that stripe
head. This will allow adding multiple disks at a time in a subesquent
patch.
To do this cleaner, refactor the check into a helper function called
stripe_ahead_of_reshape().
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Factor out two helper functions from add_stripe_bio(): one to check for
overlap (stripe_bio_overlaps()), and one to actually add the bio to the
stripe (__add_stripe_bio()). The latter function will always succeed.
This will be useful in the next patch so that overlap can be checked for
multiple disks before adding any
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When batching, every stripe head has to find the previous stripe head to
add to the batch list. This involves taking the hash lock which is
highly contended during IO.
Instead of finding the previous stripe_head each time, store a
reference to the previous stripe_head in a pointer so that it doesn't
require taking the contended lock another time.
The reference to the previous stripe must be released before scheduling
and waiting for work to get done. Otherwise, it can hold up
raid5_activate_delayed() and deadlock.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The for loop with retry label can be more cleanly expressed as a while
loop by moving the logical_sector increment into the success path.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that prepare_to_wait() isn't in the way, move read_sequcount_begin()
into make_stripe_request().
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
prepare_to_wait() can be reasonably called after schedule instead of
setting a flag and preparing in the next loop iteration.
This means that prepare_to_wait() will be called before
read_seqcount_begin(), but there shouldn't be any reason that the order
matters here. On the first iteration of the loop prepare_to_wait() is
already called first.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Factor out the inner loop of raid5_make_request() into it's own helper
called make_stripe_request().
The helper returns a number of statuses: SUCCESS, RETRY,
SCHEDULE_AND_RETRY and FAIL. This makes the code a bit easier to
understand and allows the SCHEDULE_AND_RETRY path to be made common.
A context structure is added to contain do_flush. It will be used
more in subsequent patches for state that needs to be kept
outside the loop.
No functional changes intended. This will be cleaned up further in
subsequent patches to untangle the gen_lock and do_prepare logic
further.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Both uses of find_stripe() require a fairly complicated dance to
increment the reference count. Move this into a common find_get_stripe()
helper.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
stripe_add_to_batch_list() is better done in the loop in make_request
instead of inside add_stripe_bio(). This is clearer and allows for
storing the batch_head state outside the loop in a subsequent patch.
The call to add_stripe_bio() in retry_aligned_read() is for read
and batching only applies to write. So it's impossible for batching
to happen at that call site.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Break immediately if raid5_get_active_stripe() returns NULL and deindent
the rest of the loop. Annotate this check with an unlikely().
This makes the code easier to read and reduces the indentation level.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are a few uses of an ugly ternary operator in raid5_make_request()
to check if a sector is a head of a reshape sector.
Factor this out into a simple helper called ahead_of_reshape().
No functional changes intended.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The check in raid5_make_request differs very slightly from the logic
that causes it to block lower down. This likely does not cause a bug
as the check is fuzzy anyway (as reshape may move on between the first
check and the subsequent check). However, make it consistent so it can
be cleaned up in a subsequent patch.
The condition which causes the schedule is:
!(mddev->reshape_backwards ? logical_sector < conf->reshape_progress :
logical_sector >= conf->reshape_progress) &&
(mddev->reshape_backwards ? logical_sector < conf->reshape_safe :
logical_sector >= conf->reshape_safe)
The condition that causes the early bailout is made to match this.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The raid5-cache code relies on there being no IO in flight when
log_exit() is called. There are two places where this is not
guaranteed so add mddev_suspend() and mddev_resume() calls to these
sites.
The site in raid5_change_consistency_policy() is in the error path,
and another similar call site already has suspend/resume calls just
below it; so it should be equally safe to make that change here.
There is one remaining site in raid5_remove_disk() that we call log_exit()
without suspending the array. Unfortunately, as the comment stated, we
cannot call mddev_suspend from raid5d.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- Improve the type checking of request flags (Bart)
- Ensure queue mapping for a single queues always picks the right queue
(Bart)
- Sanitize the io priority handling (Jan)
- rq-qos race fix (Jinke)
- Reserved tags handling improvements (John)
- Separate memory alignment from file/disk offset aligment for O_DIRECT
(Keith)
- Add new ublk driver, userspace block driver using io_uring for
communication with the userspace backend (Ming)
- Use try_cmpxchg() to cleanup the code in various spots (Uros)
- Finally remove bdevname() (Christoph)
- Clean up the zoned device handling (Christoph)
- Clean up independent access range support (Christoph)
- Clean up and improve block sysfs handling (Christoph)
- Clean up and improve teardown of block devices.
This turns the usual two step process into something that is simpler
to implement and handle in block drivers (Christoph)
- Clean up chunk size handling (Christoph)
- Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
Ming, Sebastian, Yang, Ying)
* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
ublk_drv: fix double shift bug
ublk_drv: make sure that correct flags(features) returned to userspace
ublk_drv: fix error handling of ublk_add_dev
ublk_drv: fix lockdep warning
block: remove __blk_get_queue
block: call blk_mq_exit_queue from disk_release for never added disks
blk-mq: fix error handling in __blk_mq_alloc_disk
ublk: defer disk allocation
ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask
ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
ublk: cleanup ublk_ctrl_uring_cmd
ublk: simplify ublk_ch_open and ublk_ch_release
ublk: remove the empty open and release block device operations
ublk: remove UBLK_IO_F_PREFLUSH
ublk: add a MAINTAINERS entry
block: don't allow the same type rq_qos add more than once
mmc: fix disk/queue leak in case of adding disk failure
ublk_drv: fix an IS_ERR() vs NULL check
ublk: remove UBLK_IO_F_INTEGRITY
ublk_drv: remove unneeded semicolon
...
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Merge tag 'block-5.19-2022-07-21' of git://git.kernel.dk/linux-block
Pull block fix from Jens Axboe:
"Just a single fix for missing error propagation for an allocation
failure in raid5"
* tag 'block-5.19-2022-07-21' of git://git.kernel.dk/linux-block:
md/raid5: missing error code in setup_conf()
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-37-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.
This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.
In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.
The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.
After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40
[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There's a KASAN warning in raid5_add_disk when running the LVM testsuite.
The warning happens in the test
lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning
by verifying that rdev->saved_raid_disk is within limits.
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
There's a KASAN warning in raid5_remove_disk when running the LVM
testsuite. We fix this warning by verifying that the "number" variable is
within limits.
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Use the %pg format specifier to save on stack consumption and code size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
The discard_alignment queue limit is named a bit misleading means the
offset into the block device at which the discard granularity starts.
Setting it to the discard granularity as done by raid5 is mostly
harmless but also useless.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220418045314.360785-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A handful of functions note the device_lock must be held with a comment
but this is not comprehensive. Many other functions hold the lock when
taken so add an __must_hold() to each call to annotate when the lock is
held.
This makes it a bit easier to analyse device_lock.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
The mddev_lock should be held during raid5_remove_disk() which is when
the rdev/replacement pointers are modified. So any access to these
pointers marked __rcu should be safe whenever the mddev_lock is held.
There are numerous such access that currently produce sparse warnings.
Add a helper function, rdev_mdlock_deref() that wraps
rcu_dereference_protected() in all these instances.
This annotation fixes a number of sparse warnings.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
There are a number of accesses to __rcu variables that should be safe
because nr_pending in the disk is known to be elevated.
Create a wrapper around rcu_dereference_protected() to annotate these
accesses and verify that nr_pending is non-zero.
This fixes a number of sparse warnings.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
rdev and replacement are protected in some circumstances with
rcu_dereference and synchronize_rcu (in raid5_remove_disk()). However,
they were not annotated with __rcu so a sparse warning is emitted for
every rcu_dereference() call.
Add the __rcu annotation and fix up the initialization with
RCU_INIT_POINTER, all pointer modifications with rcu_assign_pointer(),
a few cases where the pointer value is tested with rcu_access_pointer()
and one case where READ_ONCE() is used instead of rcu_dereference(),
a case in print_raid5_conf() that should have rcu_dereference() and
rcu_read_[un]lock() calls.
Additional sparse issues will be fixed up in further commits.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Be more careful about the error returns. Most errors in this function
are actually ENOMEM, but it forcibly returns EIO if conf has been
allocated.
Instead return ret and ensure it is set appropriately before each goto
abort.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Raid456 module had allowed to achieve failed state. It was fixed by
fb73b357fb ("raid5: block failing device if raid will be failed").
This fix introduces a bug, now if raid5 fails during IO, it may result
with a hung task without completion. Faulty flag on the device is
necessary to process all requests and is checked many times, mainly in
analyze_stripe().
Allow to set faulty on drive again and set MD_BROKEN if raid is failed.
As a result, this level is allowed to achieve failed state again, but
communication with userspace (via -EBUSY status) will be preserved.
This restores possibility to fail array via #mdadm --set-faulty command
and will be fixed by additional verification on mdadm side.
Reproduction steps:
mdadm -CR imsm -e imsm -n 3 /dev/nvme[0-2]n1
mdadm -CR r5 -e imsm -l5 -n3 /dev/nvme[0-2]n1 --assume-clean
mkfs.xfs /dev/md126 -f
mount /dev/md126 /mnt/root/
fio --filename=/mnt/root/file --size=5GB --direct=1 --rw=randrw
--bs=64k --ioengine=libaio --iodepth=64 --runtime=240 --numjobs=4
--time_based --group_reporting --name=throughput-test-job
--eta-newline=1 &
echo 1 > /sys/block/nvme2n1/device/device/remove
echo 1 > /sys/block/nvme1n1/device/device/remove
[ 1475.787779] Call Trace:
[ 1475.793111] __schedule+0x2a6/0x700
[ 1475.799460] schedule+0x38/0xa0
[ 1475.805454] raid5_get_active_stripe+0x469/0x5f0 [raid456]
[ 1475.813856] ? finish_wait+0x80/0x80
[ 1475.820332] raid5_make_request+0x180/0xb40 [raid456]
[ 1475.828281] ? finish_wait+0x80/0x80
[ 1475.834727] ? finish_wait+0x80/0x80
[ 1475.841127] ? finish_wait+0x80/0x80
[ 1475.847480] md_handle_request+0x119/0x190
[ 1475.854390] md_make_request+0x8a/0x190
[ 1475.861041] generic_make_request+0xcf/0x310
[ 1475.868145] submit_bio+0x3c/0x160
[ 1475.874355] iomap_dio_submit_bio.isra.20+0x51/0x60
[ 1475.882070] iomap_dio_bio_actor+0x175/0x390
[ 1475.889149] iomap_apply+0xff/0x310
[ 1475.895447] ? iomap_dio_bio_actor+0x390/0x390
[ 1475.902736] ? iomap_dio_bio_actor+0x390/0x390
[ 1475.909974] iomap_dio_rw+0x2f2/0x490
[ 1475.916415] ? iomap_dio_bio_actor+0x390/0x390
[ 1475.923680] ? atime_needs_update+0x77/0xe0
[ 1475.930674] ? xfs_file_dio_aio_read+0x6b/0xe0 [xfs]
[ 1475.938455] xfs_file_dio_aio_read+0x6b/0xe0 [xfs]
[ 1475.946084] xfs_file_read_iter+0xba/0xd0 [xfs]
[ 1475.953403] aio_read+0xd5/0x180
[ 1475.959395] ? _cond_resched+0x15/0x30
[ 1475.965907] io_submit_one+0x20b/0x3c0
[ 1475.972398] __x64_sys_io_submit+0xa2/0x180
[ 1475.979335] ? do_io_getevents+0x7c/0xc0
[ 1475.986009] do_syscall_64+0x5b/0x1a0
[ 1475.992419] entry_SYSCALL_64_after_hwframe+0x65/0xca
[ 1476.000255] RIP: 0033:0x7f11fc27978d
[ 1476.006631] Code: Bad RIP value.
[ 1476.073251] INFO: task fio:3877 blocked for more than 120 seconds.
Cc: stable@vger.kernel.org
Fixes: fb73b357fb ("raid5: block failing device if raid will be failed")
Reviewd-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>
Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.
The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
