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* Merge branch 'for-next' of ↵Jens Axboe2019-01-032-57/+33
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/shli/md into for-linus Pull the pending 4.21 changes for md from Shaohua. * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: md: fix raid10 hang issue caused by barrier raid10: refactor common wait code from regular read/write request md: remvoe redundant condition check lib/raid6: add option to skip algo benchmarking lib/raid6: sort algos in rough performance order lib/raid6: check for assembler SSSE3 support lib/raid6: avoid __attribute_const__ redefinition lib/raid6: add missing include for raid6test md: remove set but not used variable 'bi_rdev'
| * md: fix raid10 hang issue caused by barrierGuoqing Jiang2018-12-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When both regular IO and resync IO happen at the same time, and if we also need to split regular. Then we can see tasks hang due to barrier. 1. resync thread [ 1463.757205] INFO: task md1_resync:5215 blocked for more than 480 seconds. [ 1463.757207] Not tainted 4.19.5-1-default #1 [ 1463.757209] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1463.757212] md1_resync D 0 5215 2 0x80000000 [ 1463.757216] Call Trace: [ 1463.757223] ? __schedule+0x29a/0x880 [ 1463.757231] ? raise_barrier+0x8d/0x140 [raid10] [ 1463.757236] schedule+0x78/0x110 [ 1463.757243] raise_barrier+0x8d/0x140 [raid10] [ 1463.757248] ? wait_woken+0x80/0x80 [ 1463.757257] raid10_sync_request+0x1f6/0x1e30 [raid10] [ 1463.757265] ? _raw_spin_unlock_irq+0x22/0x40 [ 1463.757284] ? is_mddev_idle+0x125/0x137 [md_mod] [ 1463.757302] md_do_sync.cold.78+0x404/0x969 [md_mod] [ 1463.757311] ? wait_woken+0x80/0x80 [ 1463.757336] ? md_rdev_init+0xb0/0xb0 [md_mod] [ 1463.757351] md_thread+0xe9/0x140 [md_mod] [ 1463.757358] ? _raw_spin_unlock_irqrestore+0x2e/0x60 [ 1463.757364] ? __kthread_parkme+0x4c/0x70 [ 1463.757369] kthread+0x112/0x130 [ 1463.757374] ? kthread_create_worker_on_cpu+0x40/0x40 [ 1463.757380] ret_from_fork+0x3a/0x50 2. regular IO [ 1463.760679] INFO: task kworker/0:8:5367 blocked for more than 480 seconds. [ 1463.760683] Not tainted 4.19.5-1-default #1 [ 1463.760684] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1463.760687] kworker/0:8 D 0 5367 2 0x80000000 [ 1463.760718] Workqueue: md submit_flushes [md_mod] [ 1463.760721] Call Trace: [ 1463.760731] ? __schedule+0x29a/0x880 [ 1463.760741] ? wait_barrier+0xdd/0x170 [raid10] [ 1463.760746] schedule+0x78/0x110 [ 1463.760753] wait_barrier+0xdd/0x170 [raid10] [ 1463.760761] ? wait_woken+0x80/0x80 [ 1463.760768] raid10_write_request+0xf2/0x900 [raid10] [ 1463.760774] ? wait_woken+0x80/0x80 [ 1463.760778] ? mempool_alloc+0x55/0x160 [ 1463.760795] ? md_write_start+0xa9/0x270 [md_mod] [ 1463.760801] ? try_to_wake_up+0x44/0x470 [ 1463.760810] raid10_make_request+0xc1/0x120 [raid10] [ 1463.760816] ? wait_woken+0x80/0x80 [ 1463.760831] md_handle_request+0x121/0x190 [md_mod] [ 1463.760851] md_make_request+0x78/0x190 [md_mod] [ 1463.760860] generic_make_request+0x1c6/0x470 [ 1463.760870] raid10_write_request+0x77a/0x900 [raid10] [ 1463.760875] ? wait_woken+0x80/0x80 [ 1463.760879] ? mempool_alloc+0x55/0x160 [ 1463.760895] ? md_write_start+0xa9/0x270 [md_mod] [ 1463.760904] raid10_make_request+0xc1/0x120 [raid10] [ 1463.760910] ? wait_woken+0x80/0x80 [ 1463.760926] md_handle_request+0x121/0x190 [md_mod] [ 1463.760931] ? _raw_spin_unlock_irq+0x22/0x40 [ 1463.760936] ? finish_task_switch+0x74/0x260 [ 1463.760954] submit_flushes+0x21/0x40 [md_mod] So resync io is waiting for regular write io to complete to decrease nr_pending (conf->barrier++ is called before waiting). The regular write io splits another bio after call wait_barrier which call nr_pending++, then the splitted bio would continue with raid10_write_request -> wait_barrier, so the splitted bio has to wait for barrier to be zero, then deadlock happens as follows. resync io regular io raise_barrier wait_barrier generic_make_request wait_barrier To resolve the issue, we need to call allow_barrier to decrease nr_pending before generic_make_request since regular IO is not issued to underlying devices, and wait_barrier is called again to ensure no internal IO happening. Fixes: fc9977dd069e ("md/raid10: simplify the splitting of requests.") Reported-and-tested-by: Siniša Bandin <sinisa@4net.rs> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * raid10: refactor common wait code from regular read/write requestGuoqing Jiang2018-12-201-47/+25
| | | | | | | | | | | | | | | | | | | | 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>
| * md: remvoe redundant condition checkChengguang Xu2018-12-201-8/+4
| | | | | | | | | | | | | | | | | | 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>
| * md: remove set but not used variable 'bi_rdev'Yue Haibing2018-12-201-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 1501efadc524 ("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>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-12-284-4/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: - large KASAN update to use arm's "software tag-based mode" - a few misc things - sh updates - ocfs2 updates - just about all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits) kernel/fork.c: mark 'stack_vm_area' with __maybe_unused memcg, oom: notify on oom killer invocation from the charge path mm, swap: fix swapoff with KSM pages include/linux/gfp.h: fix typo mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization memory_hotplug: add missing newlines to debugging output mm: remove __hugepage_set_anon_rmap() include/linux/vmstat.h: remove unused page state adjustment macro mm/page_alloc.c: allow error injection mm: migrate: drop unused argument of migrate_page_move_mapping() blkdev: avoid migration stalls for blkdev pages mm: migrate: provide buffer_migrate_page_norefs() mm: migrate: move migrate_page_lock_buffers() mm: migrate: lock buffers before migrate_page_move_mapping() mm: migration: factor out code to compute expected number of page references mm, page_alloc: enable pcpu_drain with zone capability kmemleak: add config to select auto scan mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init ...
| * | mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS2018-12-284-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'for-4.21/dm-changes' of ↵Linus Torvalds2018-12-2817-82/+121
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Eliminate a couple indirect calls from bio-based DM core. - Fix DM to allow reads that exceed readahead limits by setting io_pages in the backing_dev_info. - A couple code cleanups in request-based DM. - Fix various DM targets to check for device sector overflow if CONFIG_LBDAF is not set. - Use u64 instead of sector_t to store iv_offset in DM crypt; sector_t isn't large enough on 32bit when CONFIG_LBDAF is not set. - Performance fixes to DM's kcopyd and the snapshot target focused on limiting memory use and workqueue stalls. - Fix typos in the integrity and writecache targets. - Log which algorithm is used for dm-crypt's encryption and dm-integrity's hashing. - Fix false -EBUSY errors in DM raid target's handling of check/repair messages. - Fix DM flakey target's corrupt_bio_byte feature to reliably corrupt the Nth byte in a bio's payload. * tag 'for-4.21/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: do not allow readahead to limit IO size dm raid: fix false -EBUSY when handling check/repair message dm rq: cleanup leftover code from recently removed q->mq_ops branching dm verity: log the hash algorithm implementation dm crypt: log the encryption algorithm implementation dm integrity: fix spelling mistake in workqueue name dm flakey: Properly corrupt multi-page bios. dm: Check for device sector overflow if CONFIG_LBDAF is not set dm crypt: use u64 instead of sector_t to store iv_offset dm kcopyd: Fix bug causing workqueue stalls dm snapshot: Fix excessive memory usage and workqueue stalls dm bufio: update comment in dm-bufio.c dm writecache: fix typo in error msg for creating writecache_flush_thread dm: remove indirect calls from __send_changing_extent_only() dm mpath: only flush workqueue when needed dm rq: remove unused arguments from rq_completed() dm: avoid indirect call in __dm_make_request
| * | | dm: do not allow readahead to limit IO sizeJaegeuk Kim2018-12-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm raid: fix false -EBUSY when handling check/repair messageHeinz Mauelshagen2018-12-181-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm rq: cleanup leftover code from recently removed q->mq_ops branchingMike Snitzer2018-12-181-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When commit 6a23e05c2fe3c6 ("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>
| * | | dm verity: log the hash algorithm implementationEric Biggers2018-12-181-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm crypt: log the encryption algorithm implementationEric Biggers2018-12-181-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm integrity: fix spelling mistake in workqueue nameColin Ian King2018-12-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm flakey: Properly corrupt multi-page bios.Sweet Tea2018-12-181-11/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm: Check for device sector overflow if CONFIG_LBDAF is not setMilan Broz2018-12-186-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm crypt: use u64 instead of sector_t to store iv_offsetAliOS system security2018-12-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm kcopyd: Fix bug causing workqueue stallsNikos Tsironis2018-12-181-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm snapshot: Fix excessive memory usage and workqueue stallsNikos Tsironis2018-12-181-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm bufio: update comment in dm-bufio.cShenghui Wang2018-12-181-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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>
| * | | dm writecache: fix typo in error msg for creating writecache_flush_threadShenghui Wang2018-12-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm: remove indirect calls from __send_changing_extent_only()Mike Snitzer2018-12-181-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | No need to be so fancy. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * | | dm mpath: only flush workqueue when neededwuzhouhui2018-12-181-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | dm rq: remove unused arguments from rq_completed()Mike Snitzer2018-12-181-9/+5
| | | | | | | | | | | | | | | | Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * | | dm: avoid indirect call in __dm_make_requestMikulas Patocka2018-12-181-23/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-blockLinus Torvalds2018-12-2816-78/+231
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: "This is the main pull request for block/storage for 4.21. Larger than usual, it was a busy round with lots of goodies queued up. Most notable is the removal of the old IO stack, which has been a long time coming. No new features for a while, everything coming in this week has all been fixes for things that were previously merged. This contains: - Use atomic counters instead of semaphores for mtip32xx (Arnd) - Cleanup of the mtip32xx request setup (Christoph) - Fix for circular locking dependency in loop (Jan, Tetsuo) - bcache (Coly, Guoju, Shenghui) * Optimizations for writeback caching * Various fixes and improvements - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith) * host and target support for NVMe over TCP * Error log page support * Support for separate read/write/poll queues * Much improved polling * discard OOM fallback * Tracepoint improvements - lightnvm (Hans, Hua, Igor, Matias, Javier) * Igor added packed metadata to pblk. Now drives without metadata per LBA can be used as well. * Fix from Geert on uninitialized value on chunk metadata reads. * Fixes from Hans and Javier to pblk recovery and write path. * Fix from Hua Su to fix a race condition in the pblk recovery code. * Scan optimization added to pblk recovery from Zhoujie. * Small geometry cleanup from me. - Conversion of the last few drivers that used the legacy path to blk-mq (me) - Removal of legacy IO path in SCSI (me, Christoph) - Removal of legacy IO stack and schedulers (me) - Support for much better polling, now without interrupts at all. blk-mq adds support for multiple queue maps, which enables us to have a map per type. This in turn enables nvme to have separate completion queues for polling, which can then be interrupt-less. Also means we're ready for async polled IO, which is hopefully coming in the next release. - Killing of (now) unused block exports (Christoph) - Unification of the blk-rq-qos and blk-wbt wait handling (Josef) - Support for zoned testing with null_blk (Masato) - sx8 conversion to per-host tag sets (Christoph) - IO priority improvements (Damien) - mq-deadline zoned fix (Damien) - Ref count blkcg series (Dennis) - Lots of blk-mq improvements and speedups (me) - sbitmap scalability improvements (me) - Make core inflight IO accounting per-cpu (Mikulas) - Export timeout setting in sysfs (Weiping) - Cleanup the direct issue path (Jianchao) - Export blk-wbt internals in block debugfs for easier debugging (Ming) - Lots of other fixes and improvements" * tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits) kyber: use sbitmap add_wait_queue/list_del wait helpers sbitmap: add helpers for add/del wait queue handling block: save irq state in blkg_lookup_create() dm: don't reuse bio for flushes nvme-pci: trace SQ status on completions nvme-rdma: implement polling queue map nvme-fabrics: allow user to pass in nr_poll_queues nvme-fabrics: allow nvmf_connect_io_queue to poll nvme-core: optionally poll sync commands block: make request_to_qc_t public nvme-tcp: fix spelling mistake "attepmpt" -> "attempt" nvme-tcp: fix endianess annotations nvmet-tcp: fix endianess annotations nvme-pci: refactor nvme_poll_irqdisable to make sparse happy nvme-pci: only set nr_maps to 2 if poll queues are supported nvmet: use a macro for default error location nvmet: fix comparison of a u16 with -1 blk-mq: enable IO poll if .nr_queues of type poll > 0 blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight() blk-mq: skip zero-queue maps in blk_mq_map_swqueue ...
| * | | dm: don't reuse bio for flushesJens Axboe2018-12-192-13/+25
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 5cdf2e3fea5e ("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>
| * | blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()Jens Axboe2018-12-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: print number of keys in trace_bcache_journal_writeGuoju Fang2018-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: set writeback_percent in a flexible rangeColy Li2018-12-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: make cutoff_writeback and cutoff_writeback_sync tunableColy Li2018-12-133-2/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: add MODULE_DESCRIPTION informationColy Li2018-12-131-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: option to automatically run gc thread after writebackColy Li2018-12-134-0/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: introduce force_wake_up_gc()Coly Li2018-12-132-15/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: cannot set writeback_running via sysfs if no writeback kthread createdShenghui Wang2018-12-131-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "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>
| * | bcache: do not mark writeback_running too earlyShenghui Wang2018-12-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: update comment in sysfs.cShenghui Wang2018-12-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have struct cached_dev allocated by kzalloc in register_bcache(), which initializes all the fields of cached_dev with 0s. And commit ce4c3e19e520 ("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>
| * | bcache: update comment for bch_data_insertShenghui Wang2018-12-131-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 220bb38c21b8 ("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>
| * | bcache: do not check if debug dentry is ERR or NULL explicitly on removeShenghui Wang2018-12-132-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | bcache: add comment for cache_set->fill_iterShenghui Wang2018-12-132-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | dm: fix request-based dm's use of dm_wait_for_completionMike Snitzer2018-12-112-5/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | dm: fix inflight IO checkJens Axboe2018-12-101-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 6f75723190d8 ("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>
| * | dm: remove the pending IO accountingMikulas Patocka2018-12-102-21/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the "pending" atomic counters, that duplicate block-core's in_flight counters, and update md_in_flight() to look at percpu in_flight counters. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | block: stop passing 'cpu' to all percpu stats methodsMike Snitzer2018-12-101-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | dm rq: leverage blk_mq_queue_busy() to check for outstanding IOMike Snitzer2018-12-101-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | dm: dont rewrite dm_disk(md)->part0.in_flightMikulas Patocka2018-12-101-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | blkcg: remove bio->bi_css and instead use bio->bi_blkgDennis Zhou2018-12-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | dm: set the static flush bio device on demandDennis Zhou2018-12-071-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | block: add queue_is_mq() helperJens Axboe2018-11-162-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various spots check for q->mq_ops being non-NULL, but provide a helper to do this instead. Where the ->mq_ops != NULL check is redundant, remove it. Since mq == rq-based now that legacy is gone, get rid of the queue_is_rq_based() and just use queue_is_mq() everywhere. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | block: remove the lock argument to blk_alloc_queue_nodeChristoph Hellwig2018-11-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | With the legacy request path gone there is no real need to override the queue_lock. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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