Both raid10_read_request and raid10_write_request share
the same code at the beginning of them, so introduce
regular_request_wait to clean up code, and call it in
both request functions.
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
mempool_destroy() can handle NULL pointer correctly,
so there is no need to check NULL pointer before calling
mempool_destroy().
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/md/md.c: In function 'md_integrity_add_rdev':
drivers/md/md.c:2149:24: warning:
variable 'bi_rdev' set but not used [-Wunused-but-set-variable]
It not used any more after commit
1501efadc5 ("md/raid: only permit hot-add of compatible integrity profiles")
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Shaohua Li <shli@fb.com>
DM currently has a statically allocated bio that it uses to issue empty
flushes. It doesn't submit this bio, it just uses it for maintaining
state while setting up clones. Multiple users can access this bio at the
same time. This wasn't previously an issue, even if it was a bit iffy,
but with the blkg associations it can become one.
We setup the blkg association, then clone bio's and submit, then remove
the blkg assocation again. But since we can have multiple tasks doing
this at the same time, against multiple blkg's, then we can either lose
references to a blkg, or put it twice. The latter causes complaints on
the percpu ref being <= 0 when released, and can cause use-after-free as
well. Ming reports that xfstest generic/475 triggers this:
------------[ cut here ]------------
percpu ref (blkg_release) <= 0 (0) after switching to atomic
WARNING: CPU: 13 PID: 0 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x2c9/0x4a0
Switch to just using an on-stack bio for this, and get rid of the
embedded bio.
Fixes: 5cdf2e3fea ("blkcg: associate blkg when associating a device")
Reported-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Update DM to set the bdi's io_pages. This fixes reads to be capped at
the device's max request size (even if user's read IO exceeds the
established readahead setting).
Fixes: 9491ae4a ("mm: don't cap request size based on read-ahead setting")
Cc: stable@vger.kernel.org
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Sending a check/repair message infrequently leads to -EBUSY instead of
properly identifying an active resync. This occurs because
raid_message() is testing recovery bits in a racy way.
Fix by calling decipher_sync_action() from raid_message() to properly
identify the idle state of the RAID device.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When commit 6a23e05c2f ("dm: remove legacy request-based IO path")
removed some q->mq_ops branching from map_request() it left in place a
goto that was only needed if that branching (and conditional 'r'
assignment) existed. Now that the branching is gone map_request()'s
goto can be removed too.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Log the hash algorithm's driver name when a dm-verity target is created.
This will help people determine whether the expected implementation is
being used. It can make an enormous difference; e.g., SHA-256 on ARM
can be 8x faster with the crypto extensions than without. It can also
be useful to know if an implementation using an external crypto
accelerator is being used instead of a software implementation.
Example message:
[ 35.281945] device-mapper: verity: sha256 using implementation "sha256-ce"
We've already found the similar message in fs/crypto/keyinfo.c to be
very useful.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Log the encryption algorithm's driver name when a dm-crypt target is
created. This will help people determine whether the expected
implementation is being used. In some cases we've seen people do
benchmarks and reject using encryption for performance reasons, when in
fact they used a much slower implementation than was possible on the
hardware. It can make an enormous difference; e.g., AES-XTS on ARM can
be over 10x faster with the crypto extensions than without. It can also
be useful to know if an implementation using an external crypto
accelerator is being used instead of a software implementation.
Example message:
[ 29.307629] device-mapper: crypt: xts(aes) using implementation "xts-aes-ce"
We've already found the similar message in fs/crypto/keyinfo.c to be
very useful.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Rename the workqueue from dm-intergrity-recalc to dm-integrity-recalc.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The flakey target is documented to be able to corrupt the Nth byte in
a bio, but does not corrupt byte indices after the first biovec in the
bio. Change the corrupting function to actually corrupt the Nth byte
no matter in which biovec that index falls.
A test device generating two-page bios, atop a flakey device configured
to corrupt a byte index on the second page, verified both the failure
to corrupt before this patch and the expected corruption after this
change.
Signed-off-by: John Dorminy <jdorminy@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reference to a device in device-mapper table contains offset in sectors.
If the sector_t is 32bit integer (CONFIG_LBDAF is not set), then
several device-mapper targets can overflow this offset and validity
check is then performed on a wrong offset and a wrong table is activated.
See for example (on 32bit without CONFIG_LBDAF) this overflow:
# dmsetup create test --table "0 2048 linear /dev/sdg 4294967297"
# dmsetup table test
0 2048 linear 8:96 1
This patch adds explicit check for overflow if the offset is sector_t type.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The iv_offset in the mapping table of crypt target is a 64bit number when
IV algorithm is plain64, plain64be, essiv or benbi. It will be assigned to
iv_offset of struct crypt_config, cc_sector of struct convert_context and
iv_sector of struct dm_crypt_request. These structures members are defined
as a sector_t. But sector_t is 32bit when CONFIG_LBDAF is not set in 32bit
kernel. In this situation sector_t is not big enough to store the 64bit
iv_offset.
Here is a reproducer.
Prepare test image and device (loop is automatically allocated by cryptsetup):
# dd if=/dev/zero of=tst.img bs=1M count=1
# echo "tst"|cryptsetup open --type plain -c aes-xts-plain64 \
--skip 500000000000000000 tst.img test
On 32bit system (use IV offset value that overflows to 64bit; CONFIG_LBDAF if off)
and device checksum is wrong:
# dmsetup table test --showkeys
0 2048 crypt aes-xts-plain64 dfa7cfe3c481f2239155739c42e539ae8f2d38f304dcc89d20b26f69daaf0933 3551657984 7:0 0
# sha256sum /dev/mapper/test
533e25c09176632b3794f35303488c4a8f3f965dffffa6ec2df347c168cb6c19 /dev/mapper/test
On 64bit system (and on 32bit system with the patch), table and checksum is now correct:
# dmsetup table test --showkeys
0 2048 crypt aes-xts-plain64 dfa7cfe3c481f2239155739c42e539ae8f2d38f304dcc89d20b26f69daaf0933 500000000000000000 7:0 0
# sha256sum /dev/mapper/test
5d16160f9d5f8c33d8051e65fdb4f003cc31cd652b5abb08f03aa6fce0df75fc /dev/mapper/test
Signed-off-by: AliOS system security <alios_sys_security@linux.alibaba.com>
Tested-and-Reviewed-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When using kcopyd to run callbacks through dm_kcopyd_do_callback() or
submitting copy jobs with a source size of 0, the jobs are pushed
directly to the complete_jobs list, which could be under processing by
the kcopyd thread. As a result, the kcopyd thread can continue running
completed jobs indefinitely, without releasing the CPU, as long as
someone keeps submitting new completed jobs through the aforementioned
paths. Processing of work items, queued for execution on the same CPU as
the currently running kcopyd thread, is thus stalled for excessive
amounts of time, hurting performance.
Running the following test, from the device mapper test suite [1],
dmtest run --suite snapshot -n parallel_io_to_many_snaps_N
, with 8 active snapshots, we get, in dmesg, messages like the
following:
[68899.948523] BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 95s!
[68899.949282] Showing busy workqueues and worker pools:
[68899.949288] workqueue events: flags=0x0
[68899.949295] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256
[68899.949306] pending: vmstat_shepherd, cache_reap
[68899.949331] workqueue mm_percpu_wq: flags=0x8
[68899.949337] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[68899.949345] pending: vmstat_update
[68899.949387] workqueue dm_bufio_cache: flags=0x8
[68899.949392] pwq 4: cpus=2 node=0 flags=0x0 nice=0 active=1/256
[68899.949400] pending: work_fn [dm_bufio]
[68899.949423] workqueue kcopyd: flags=0x8
[68899.949429] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[68899.949437] pending: do_work [dm_mod]
[68899.949452] workqueue kcopyd: flags=0x8
[68899.949458] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256
[68899.949466] in-flight: 13:do_work [dm_mod]
[68899.949474] pending: do_work [dm_mod]
[68899.949487] workqueue kcopyd: flags=0x8
[68899.949493] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[68899.949501] pending: do_work [dm_mod]
[68899.949515] workqueue kcopyd: flags=0x8
[68899.949521] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[68899.949529] pending: do_work [dm_mod]
[68899.949541] workqueue kcopyd: flags=0x8
[68899.949547] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[68899.949555] pending: do_work [dm_mod]
[68899.949568] pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=95s workers=4 idle: 27130 27223 1084
Fix this by splitting the complete_jobs list into two parts: A user
facing part, named callback_jobs, and one used internally by kcopyd,
retaining the name complete_jobs. dm_kcopyd_do_callback() and
dispatch_job() now push their jobs to the callback_jobs list, which is
spliced to the complete_jobs list once, every time the kcopyd thread
wakes up. This prevents kcopyd from hogging the CPU indefinitely and
causing workqueue stalls.
Re-running the aforementioned test:
* Workqueue stalls are eliminated
* The maximum writing time among all targets is reduced from 09m37.10s
to 06m04.85s and the total run time of the test is reduced from
10m43.591s to 7m19.199s
[1] https://github.com/jthornber/device-mapper-test-suite
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
kcopyd has no upper limit to the number of jobs one can allocate and
issue. Under certain workloads this can lead to excessive memory usage
and workqueue stalls. For example, when creating multiple dm-snapshot
targets with a 4K chunk size and then writing to the origin through the
page cache. Syncing the page cache causes a large number of BIOs to be
issued to the dm-snapshot origin target, which itself issues an even
larger (because of the BIO splitting taking place) number of kcopyd
jobs.
Running the following test, from the device mapper test suite [1],
dmtest run --suite snapshot -n many_snapshots_of_same_volume_N
, with 8 active snapshots, results in the kcopyd job slab cache growing
to 10G. Depending on the available system RAM this can lead to the OOM
killer killing user processes:
[463.492878] kthreadd invoked oom-killer: gfp_mask=0x6040c0(GFP_KERNEL|__GFP_COMP),
nodemask=(null), order=1, oom_score_adj=0
[463.492894] kthreadd cpuset=/ mems_allowed=0
[463.492948] CPU: 7 PID: 2 Comm: kthreadd Not tainted 4.19.0-rc7 #3
[463.492950] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[463.492952] Call Trace:
[463.492964] dump_stack+0x7d/0xbb
[463.492973] dump_header+0x6b/0x2fc
[463.492987] ? lockdep_hardirqs_on+0xee/0x190
[463.493012] oom_kill_process+0x302/0x370
[463.493021] out_of_memory+0x113/0x560
[463.493030] __alloc_pages_slowpath+0xf40/0x1020
[463.493055] __alloc_pages_nodemask+0x348/0x3c0
[463.493067] cache_grow_begin+0x81/0x8b0
[463.493072] ? cache_grow_begin+0x874/0x8b0
[463.493078] fallback_alloc+0x1e4/0x280
[463.493092] kmem_cache_alloc_node+0xd6/0x370
[463.493098] ? copy_process.part.31+0x1c5/0x20d0
[463.493105] copy_process.part.31+0x1c5/0x20d0
[463.493115] ? __lock_acquire+0x3cc/0x1550
[463.493121] ? __switch_to_asm+0x34/0x70
[463.493129] ? kthread_create_worker_on_cpu+0x70/0x70
[463.493135] ? finish_task_switch+0x90/0x280
[463.493165] _do_fork+0xe0/0x6d0
[463.493191] ? kthreadd+0x19f/0x220
[463.493233] kernel_thread+0x25/0x30
[463.493235] kthreadd+0x1bf/0x220
[463.493242] ? kthread_create_on_cpu+0x90/0x90
[463.493248] ret_from_fork+0x3a/0x50
[463.493279] Mem-Info:
[463.493285] active_anon:20631 inactive_anon:4831 isolated_anon:0
[463.493285] active_file:80216 inactive_file:80107 isolated_file:435
[463.493285] unevictable:0 dirty:51266 writeback:109372 unstable:0
[463.493285] slab_reclaimable:31191 slab_unreclaimable:3483521
[463.493285] mapped:526 shmem:4903 pagetables:1759 bounce:0
[463.493285] free:33623 free_pcp:2392 free_cma:0
...
[463.493489] Unreclaimable slab info:
[463.493513] Name Used Total
[463.493522] bio-6 1028KB 1028KB
[463.493525] bio-5 1028KB 1028KB
[463.493528] dm_snap_pending_exception 236783KB 243789KB
[463.493531] dm_exception 41KB 42KB
[463.493534] bio-4 1216KB 1216KB
[463.493537] bio-3 439396KB 439396KB
[463.493539] kcopyd_job 6973427KB 6973427KB
...
[463.494340] Out of memory: Kill process 1298 (ruby2.3) score 1 or sacrifice child
[463.494673] Killed process 1298 (ruby2.3) total-vm:435740kB, anon-rss:20180kB, file-rss:4kB, shmem-rss:0kB
[463.506437] oom_reaper: reaped process 1298 (ruby2.3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
Moreover, issuing a large number of kcopyd jobs results in kcopyd
hogging the CPU, while processing them. As a result, processing of work
items, queued for execution on the same CPU as the currently running
kcopyd thread, is stalled for long periods of time, hurting performance.
Running the aforementioned test we get, in dmesg, messages like the
following:
[67501.194592] BUG: workqueue lockup - pool cpus=4 node=0 flags=0x0 nice=0 stuck for 27s!
[67501.195586] Showing busy workqueues and worker pools:
[67501.195591] workqueue events: flags=0x0
[67501.195597] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195611] pending: cache_reap
[67501.195641] workqueue mm_percpu_wq: flags=0x8
[67501.195645] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195656] pending: vmstat_update
[67501.195682] workqueue kblockd: flags=0x18
[67501.195687] pwq 5: cpus=2 node=0 flags=0x0 nice=-20 active=1/256
[67501.195698] pending: blk_timeout_work
[67501.195753] workqueue kcopyd: flags=0x8
[67501.195757] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195768] pending: do_work [dm_mod]
[67501.195802] workqueue kcopyd: flags=0x8
[67501.195806] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195817] pending: do_work [dm_mod]
[67501.195834] workqueue kcopyd: flags=0x8
[67501.195838] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195848] pending: do_work [dm_mod]
[67501.195881] workqueue kcopyd: flags=0x8
[67501.195885] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
[67501.195896] pending: do_work [dm_mod]
[67501.195920] workqueue kcopyd: flags=0x8
[67501.195924] pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=2/256
[67501.195935] in-flight: 67:do_work [dm_mod]
[67501.195945] pending: do_work [dm_mod]
[67501.195961] pool 8: cpus=4 node=0 flags=0x0 nice=0 hung=27s workers=3 idle: 129 23765
The root cause for these issues is the way dm-snapshot uses kcopyd. In
particular, the lack of an explicit or implicit limit to the maximum
number of in-flight COW jobs. The merging path is not affected because
it implicitly limits the in-flight kcopyd jobs to one.
Fix these issues by using a semaphore to limit the maximum number of
in-flight kcopyd jobs. We grab the semaphore before allocating a new
kcopyd job in start_copy() and start_full_bio() and release it after the
job finishes in copy_callback().
The initial semaphore value is configurable through a module parameter,
to allow fine tuning the maximum number of in-flight COW jobs. Setting
this parameter to zero initializes the semaphore to INT_MAX.
A default value of 2048 maximum in-flight kcopyd jobs was chosen. This
value was decided experimentally as a trade-off between memory
consumption, stalling the kernel's workqueues and maintaining a high
enough throughput.
Re-running the aforementioned test:
* Workqueue stalls are eliminated
* kcopyd's job slab cache uses a maximum of 130MB
* The time taken by the test to write to the snapshot-origin target is
reduced from 05m20.48s to 03m26.38s
[1] https://github.com/jthornber/device-mapper-test-suite
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* Hashtable has been replaced by rbtree to manage buffers.
Update the comment.
* Fix typo in the comment for dm_bufio_issue_flush
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The error msg should be "flush thread" instead of "endio thread"
for writecache_flush_thread.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The workqueues are shared by many multipath devices, only flush whole
workqueue when necessary. Otherwise, we just flush works as needed.
Signed-off-by: wuzhouhui <wuzhouhui14@mails.ucas.ac.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Indirect calls are inefficient because of retpolines that are used for
spectre workaround. This patch replaces an indirect call with a condition
(that can be predicted by the branch predictor).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
There's a single user of this function, dm, and dm just wants
to check if IO is inflight, not that it's just allocated.
This fixes a hang with srp/002 in blktests with dm, where it tries
to suspend but waits for inflight IO to finish first. As it checks
for just allocated requests, this fails.
Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Sometimes flush journal may be very frequent, so it's useful to dump
number of keys every time write journal.
Signed-off-by: Guoju Fang <fangguoju@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Because CUTOFF_WRITEBACK is defined as 40, so before the changes of
dynamic cutoff writeback values, writeback_percent is limited to [0,
CUTOFF_WRITEBACK]. Any value larger than CUTOFF_WRITEBACK will be fixed
up to 40.
Now cutof writeback limit is a dynamic value bch_cutoff_writeback, so
the range of writeback_percent can be a more flexible range as [0,
bch_cutoff_writeback]. The flexibility is, it can be expended to a
larger or smaller range than [0, 40], depends on how value
bch_cutoff_writeback is specified.
The default value is still strongly recommended to most of users for
most of workloads. But for people who want to do research on bcache
writeback perforamnce tuning, they may have chance to specify more
flexible writeback_percent in range [0, 70].
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently the cutoff writeback and cutoff writeback sync thresholds are
defined by CUTOFF_WRITEBACK (40) and CUTOFF_WRITEBACK_SYNC (70) as
static values. Most of time these they work fine, but when people want
to do research on bcache writeback mode performance tuning, there is no
chance to modify the soft and hard cutoff writeback values.
This patch introduces two module parameters bch_cutoff_writeback_sync
and bch_cutoff_writeback which permit people to tune the values when
loading bcache.ko. If they are not specified by module loading, current
values CUTOFF_WRITEBACK_SYNC and CUTOFF_WRITEBACK will be used as
default and nothing changes.
When people want to tune this two values,
- cutoff_writeback can be set in range [1, 70]
- cutoff_writeback_sync can be set in range [1, 90]
- cutoff_writeback always <= cutoff_writeback_sync
The default values are strongly recommended to most of users for most of
workloads. Anyway, if people wants to take their own risk to do research
on new writeback cutoff tuning for their own workload, now they can make
it.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch moves MODULE_AUTHOR and MODULE_LICENSE to end of super.c, and
add MODULE_DESCRIPTION("Bcache: a Linux block layer cache").
This is preparation for adding module parameters.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The option gc_after_writeback is disabled by default, because garbage
collection will discard SSD data which drops cached data.
Echo 1 into /sys/fs/bcache/<UUID>/internal/gc_after_writeback will
enable this option, which wakes up gc thread when writeback accomplished
and all cached data is clean.
This option is helpful for people who cares writing performance more. In
heavy writing workload, all cached data can be clean only happens when
writeback thread cleans all cached data in I/O idle time. In such
situation a following gc running may help to shrink bcache B+ tree and
discard more clean data, which may be helpful for future writing
requests.
If you are not sure whether this is helpful for your own workload,
please leave it as disabled by default.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Garbage collection thread starts to work when c->sectors_to_gc is
negative value, otherwise nothing will happen even the gc thread is
woken up by wake_up_gc().
force_wake_up_gc() sets c->sectors_to_gc to -1 before calling
wake_up_gc(), then gc thread may have chance to run if no one else sets
c->sectors_to_gc to a positive value before gc_should_run().
This routine can be called where the gc thread is woken up and required
to run in force.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
"echo 1 > writeback_running" marks writeback_running even if no
writeback kthread created as "d_strtoul(writeback_running)" will simply
set dc-> writeback_running without checking the existence of
dc->writeback_thread.
Add check for setting writeback_running via sysfs: if no writeback
kthread available, reject setting to 1.
v2 -> v3:
* Make message on wrong assignment more clear.
* Print name of bcache device instead of name of backing device.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A fresh backing device is not attached to any cache_set, and
has no writeback kthread created until first attached to some
cache_set.
But bch_cached_dev_writeback_init run
"
dc->writeback_running = true;
WARN_ON(test_and_clear_bit(BCACHE_DEV_WB_RUNNING,
&dc->disk.flags));
"
for any newly formatted backing devices.
For a fresh standalone backing device, we can get something like
following even if no writeback kthread created:
------------------------
/sys/block/bcache0/bcache# cat writeback_running
1
/sys/block/bcache0/bcache# cat writeback_rate_debug
rate: 512.0k/sec
dirty: 0.0k
target: 0.0k
proportional: 0.0k
integral: 0.0k
change: 0.0k/sec
next io: -15427384ms
The none ZERO fields are misleading as no alive writeback kthread yet.
Set dc->writeback_running false as no writeback thread created in
bch_cached_dev_writeback_init().
We have writeback thread created and woken up in bch_cached_dev_writeback
_start(). Set dc->writeback_running true before bch_writeback_queue()
called, as a writeback thread will check if dc->writeback_running is true
before writing back dirty data, and hung if false detected.
After the change, we can get the following output for a fresh standalone
backing device:
-----------------------
/sys/block/bcache0/bcache$ cat writeback_running
0
/sys/block/bcache0/bcache# cat writeback_rate_debug
rate: 0.0k/sec
dirty: 0.0k
target: 0.0k
proportional: 0.0k
integral: 0.0k
change: 0.0k/sec
next io: 0ms
v1 -> v2:
Set dc->writeback_running before bch_writeback_queue() called,
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have struct cached_dev allocated by kzalloc in register_bcache(),
which initializes all the fields of cached_dev with 0s. And commit
ce4c3e19e5 ("bcache: Replace bch_read_string_list() by
__sysfs_match_string()") has remove the string "default".
Update the comment.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
commit 220bb38c21 ("bcache: Break up struct search") introduced
changes to struct search and s->iop. bypass/bio are fields of struct
data_insert_op now. Update the comment.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
debugfs_remove and debugfs_remove_recursive will check if the dentry
pointer is NULL or ERR, and will do nothing in that case.
Remove the check in cache_set_free and bch_debug_init.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have the following define for btree iterator:
struct btree_iter {
size_t size, used;
#ifdef CONFIG_BCACHE_DEBUG
struct btree_keys *b;
#endif
struct btree_iter_set {
struct bkey *k, *end;
} data[MAX_BSETS];
};
We can see that the length of data[] field is static MAX_BSETS, which is
defined as 4 currently.
But a btree node on disk could have too many bsets for an iterator to fit
on the stack - maybe far more that MAX_BSETS. Have to dynamically allocate
space to host more btree_iter_sets.
bch_cache_set_alloc() will make sure the pool cache_set->fill_iter can
allocate an iterator equipped with enough room that can host
(sb.bucket_size / sb.block_size)
btree_iter_sets, which is more than static MAX_BSETS.
bch_btree_node_read_done() will use that pool to allocate one iterator, to
host many bsets in one btree node.
Add more comment around cache_set->fill_iter to make code less confusing.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Decoupled version bump from commit f6c367585d ("dm thin: send event
about thin-pool state change _after_ making it") because version bumps
just create conflicts when backporting to the stable trees.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Sending a DM event before a thin-pool state change is about to happen is
a bug. It wasn't realized until it became clear that userspace response
to the event raced with the actual state change that the event was
meant to notify about.
Fix this by first updating internal thin-pool state to reflect what the
DM event is being issued about. This fixes a long-standing racey/buggy
userspace device-mapper-test-suite 'resize_io' test that would get an
event but not find the state it was looking for -- so it would just go
on to hang because no other events caused the test to reevaluate the
thin-pool's state.
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The md->wait waitqueue is used by both bio-based and request-based DM.
Commit dbd3bbd291 ("dm rq: leverage blk_mq_queue_busy() to check for
outstanding IO") lost sight of the requirement that
dm_wait_for_completion() must work with all types of DM devices.
Fix md_in_flight() to call the blk-mq or bio-based method accordingly.
Fixes: dbd3bbd291 ("dm rq: leverage blk_mq_queue_busy() to check for outstanding IO")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After switching to percpu inflight counters, the inflight check
is totally buggy. It's perfectly valid for some counters to be
non-zero while having a total inflight IO count of 0, that's how
these kinds of counters work (inc on one CPU, dec on another).
Fix the md_in_flight() check to sum all counters before returning
a false positive, potentially.
While at it, remove the inflight read for IO completion. We don't
need it, just wake anyone that's waiting for the IO count to drop
to zero. The caller needs to re-check that value anyway when woken,
which it does.
Fixes: 6f75723190 ("dm: remove the pending IO accounting")
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them. Just call
smp_processor_id() as needed.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that request-based dm-multipath only supports blk-mq, make use of
the newly introduced blk_mq_queue_busy() to check for outstanding IO --
rather than (ab)using the block core's in_flight counters.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
generic_start_io_acct and generic_end_io_acct already update the variable
in_flight using atomic operations, so we don't have to overwrite them
again.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Prior patches ensured that any bio that interacts with a request_queue
is properly associated with a blkg. This makes bio->bi_css unnecessary
as blkg maintains a reference to blkcg already.
This removes the bio field bi_css and transfers corresponding uses to
access via bi_blkg.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The next patch changes the macro bio_set_dev() to associate a bio with a
blkg based on the device set. However, dm creates a static bio to be
used as the basis for cloning empty flush bios on creation. The
bio_set_dev() call in alloc_dev() will cause problems with the next
patch adding association to bio_set_dev() because the call is before the
bdev is associated with a gendisk (bd_disk is %NULL). To get around
this, set the device on the static bio every time and use that to clone
to the other bios.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
struct bioctx includes the ref refcount_t to track the number of I/O
fragments used to process a target BIO as well as ensure that the zone
of the BIO is kept in the active state throughout the lifetime of the
BIO. However, since decrementing of this reference count is done in the
target .end_io method, the function bio_endio() must be called multiple
times for read and write target BIOs, which causes problems with the
value of the __bi_remaining struct bio field for chained BIOs (e.g. the
clone BIO passed by dm core is large and splits into fragments by the
block layer), resulting in incorrect values and inconsistencies with the
BIO_CHAIN flag setting. This is turn triggers the BUG_ON() call:
BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
in bio_remaining_done() called from bio_endio().
Fix this ensuring that bio_endio() is called only once for any target
BIO by always using internal clone BIOs for processing any read or
write target BIO. This allows reference counting using the target BIO
context counter to trigger the target BIO completion bio_endio() call
once all data, metadata and other zone work triggered by the BIO
complete.
Overall, this simplifies the code too as the target .end_io becomes
unnecessary and differences between read and write BIO issuing and
completion processing disappear.
Fixes: 3b1a94c88b ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise the incoming bios, of various types, won't be shaped based on
the DM device's advertised limits.
Depends-on: af67c31fba ("blk: remove bio_set arg from blk_queue_split()")
Fixes: 744889b7cb ("block: don't deal with discard limit in blkdev_issue_discard()")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise dm_bitset_cursor_begin() return -ENODATA. Other calls to
dm_bitset_cursor_begin() have similar negative checks.
Fixes inability to create a cache in passthrough mode (even though doing
so makes no sense).
Fixes: 0d963b6e65 ("dm cache metadata: fix metadata2 format's blocks_are_clean_separate_dirty")
Cc: stable@vger.kernel.org
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
'shash' algorithms are always synchronous, so passing CRYPTO_ALG_ASYNC
in the mask to crypto_alloc_shash() has no effect. Many users therefore
already don't pass it, but some still do. This inconsistency can cause
confusion, especially since the way the 'mask' argument works is
somewhat counterintuitive.
Thus, just remove the unneeded CRYPTO_ALG_ASYNC flags.
This patch shouldn't change any actual behavior.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
'cipher' algorithms (single block ciphers) are always synchronous, so
passing CRYPTO_ALG_ASYNC in the mask to crypto_alloc_cipher() has no
effect. Many users therefore already don't pass it, but some still do.
This inconsistency can cause confusion, especially since the way the
'mask' argument works is somewhat counterintuitive.
Thus, just remove the unneeded CRYPTO_ALG_ASYNC flags.
This patch shouldn't change any actual behavior.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
