- 11 Sep, 2020 4 commits
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Song Liu authored
This enables proper statistics in /proc/diskstats for md partitions. Signed-off-by:
Song Liu <songliubraving@fb.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Song Liu authored
These functions can be used to enable iostat for partitions on devices like md, bcache. Signed-off-by:
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Ming Lei authored
NVMe shares tagset between fabric queue and admin queue or between connect_q and NS queue, so hctx_may_queue() can be called to allocate request for these queues. Tags can be reserved in these tagset. Before error recovery, there is often lots of in-flight requests which can't be completed, and new reserved request may be needed in error recovery path. However, hctx_may_queue() can always return false because there is too many in-flight requests which can't be completed during error handling. Finally, nothing can proceed. Fix this issue by always allowing reserved tag allocation in hctx_may_queue(). This is reasonable because reserved tags are supposed to always be available. Reviewed-by:
Hannes Reinecke <hare@suse.de> Cc: David Milburn <dmilburn@redhat.com> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
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Tian Tao authored
scsi/sg.h is included more than once, Remove the one that isn't necessary. Signed-off-by:
Tian Tao <tiantao6@hisilicon.com> Signed-off-by:
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- 10 Sep, 2020 20 commits
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Xianting Tian authored
The test and the explaination of the patch as bellow. Before test we added more debug code in blkg_async_bio_workfn(): int count = 0 if (bios.head && bios.head->bi_next) { need_plug = true; blk_start_plug(&plug); } while ((bio = bio_list_pop(&bios))) { /*io_punt is a sysctl user interface to control the print*/ if(io_punt) { printk("[%s:%d] bio start,size:%llu,%d count=%d plug?%d\n", current->comm, current->pid, bio->bi_iter.bi_sector, (bio->bi_iter.bi_size)>>9, count++, need_plug); } submit_bio(bio); } if (need_plug) blk_finish_plug(&plug); Steps that need to be set to trigger *PUNT* io before testing: mount -t btrfs -o compress=lzo /dev/sda6 /btrfs mount -t cgroup2 nodev /cgroup2 mkdir /cgroup2/cg3 echo "+io" > /cgroup2/cgroup.subtree_control echo "8:0 wbps=1048576000" > /cgroup2/cg3/io.max #1000M/s echo $$ > /cgroup2/cg3/cgroup.procs Then use dd command to test btrfs PUNT io in current shell: dd if=/dev/zero of=/btrfs/file bs=64K count=100000 Test hardware environment as below: [root@localhost btrfs]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 2 Core(s) per socket: 8 Socket(s): 2 NUMA node(s): 2 Vendor ID: GenuineIntel With above debug code, test command and test environment, I did the tests under 3 different system loads, which are triggered by stress: 1, Run 64 threads by command "stress -c 64 &" [53615.975974] [kworker/u66:18:1490] bio start,size:45583056,8 count=0 plug?1 [53615.975980] [kworker/u66:18:1490] bio start,size:45583064,8 count=1 plug?1 [53615.975984] [kworker/u66:18:1490] bio start,size:45583072,8 count=2 plug?1 [53615.975987] [kworker/u66:18:1490] bio start,size:45583080,8 count=3 plug?1 [53615.975990] [kworker/u66:18:1490] bio start,size:45583088,8 count=4 plug?1 [53615.975993] [kworker/u66:18:1490] bio start,size:45583096,8 count=5 plug?1 ... ... [53615.977041] [kworker/u66:18:1490] bio start,size:45585480,8 count=303 plug?1 [53615.977044] [kworker/u66:18:1490] bio start,size:45585488,8 count=304 plug?1 [53615.977047] [kworker/u66:18:1490] bio start,size:45585496,8 count=305 plug?1 [53615.977050] [kworker/u66:18:1490] bio start,size:45585504,8 count=306 plug?1 [53615.977053] [kworker/u66:18:1490] bio start,size:45585512,8 count=307 plug?1 [53615.977056] [kworker/u66:18:1490] bio start,size:45585520,8 count=308 plug?1 [53615.977058] [kworker/u66:18:1490] bio start,size:45585528,8 count=309 plug?1 2, Run 32 threads by command "stress -c 32 &" [50586.290521] [kworker/u66:6:32351] bio start,size:45806496,8 count=0 plug?1 [50586.290526] [kworker/u66:6:32351] bio start,size:45806504,8 count=1 plug?1 [50586.290529] [kworker/u66:6:32351] bio start,size:45806512,8 count=2 plug?1 [50586.290531] [kworker/u66:6:32351] bio start,size:45806520,8 count=3 plug?1 [50586.290533] [kworker/u66:6:32351] bio start,size:45806528,8 count=4 plug?1 [50586.290535] [kworker/u66:6:32351] bio start,size:45806536,8 count=5 plug?1 ... ... [50586.299640] [kworker/u66:5:32350] bio start,size:45808576,8 count=252 plug?1 [50586.299643] [kworker/u66:5:32350] bio start,size:45808584,8 count=253 plug?1 [50586.299646] [kworker/u66:5:32350] bio start,size:45808592,8 count=254 plug?1 [50586.299649] [kworker/u66:5:32350] bio start,size:45808600,8 count=255 plug?1 [50586.299652] [kworker/u66:5:32350] bio start,size:45808608,8 count=256 plug?1 [50586.299663] [kworker/u66:5:32350] bio start,size:45808616,8 count=257 plug?1 [50586.299665] [kworker/u66:5:32350] bio start,size:45808624,8 count=258 plug?1 [50586.299668] [kworker/u66:5:32350] bio start,size:45808632,8 count=259 plug?1 3, Don't run thread by stress [50861.355246] [kworker/u66:19:32376] bio start,size:13544504,8 count=0 plug?0 [50861.355288] [kworker/u66:19:32376] bio start,size:13544512,8 count=0 plug?0 [50861.355322] [kworker/u66:19:32376] bio start,size:13544520,8 count=0 plug?0 [50861.355353] [kworker/u66:19:32376] bio start,size:13544528,8 count=0 plug?0 [50861.355392] [kworker/u66:19:32376] bio start,size:13544536,8 count=0 plug?0 [50861.355431] [kworker/u66:19:32376] bio start,size:13544544,8 count=0 plug?0 [50861.355468] [kworker/u66:19:32376] bio start,size:13544552,8 count=0 plug?0 [50861.355499] [kworker/u66:19:32376] bio start,size:13544560,8 count=0 plug?0 [50861.355532] [kworker/u66:19:32376] bio start,size:13544568,8 count=0 plug?0 [50861.355575] [kworker/u66:19:32376] bio start,size:13544576,8 count=0 plug?0 [50861.355618] [kworker/u66:19:32376] bio start,size:13544584,8 count=0 plug?0 [50861.355659] [kworker/u66:19:32376] bio start,size:13544592,8 count=0 plug?0 [50861.355740] [kworker/u66:0:32346] bio start,size:13544600,8 count=0 plug?1 [50861.355748] [kworker/u66:0:32346] bio start,size:13544608,8 count=1 plug?1 [50861.355962] [kworker/u66:2:32347] bio start,size:13544616,8 count=0 plug?0 [50861.356272] [kworker/u66:7:31962] bio start,size:13544624,8 count=0 plug?0 [50861.356446] [kworker/u66:7:31962] bio start,size:13544632,8 count=0 plug?0 [50861.356567] [kworker/u66:7:31962] bio start,size:13544640,8 count=0 plug?0 [50861.356707] [kworker/u66:19:32376] bio start,size:13544648,8 count=0 plug?0 [50861.356748] [kworker/u66:15:32355] bio start,size:13544656,8 count=0 plug?0 [50861.356825] [kworker/u66:17:31970] bio start,size:13544664,8 count=0 plug?0 Analysis of above 3 test results with different system load: >From above test, we can see more and more continuous bios can be plugged with system load increasing. When run "stress -c 64 &", 310 continuous bios are plugged; When run "stress -c 32 &", 260 continuous bios are plugged; When don't run stress, at most only 2 continuous bios are plugged, in most cases, bio_list only contains one single bio. How to explain above phenomenon: We know, in submit_bio(), if the bio is a REQ_CGROUP_PUNT io, it will queue a work to workqueue blkcg_punt_bio_wq. But when the workqueue is scheduled, it depends on the system load. When system load is low, the workqueue will be quickly scheduled, and the bio in bio_list will be quickly processed in blkg_async_bio_workfn(), so there is less chance that the same io submit thread can add multiple continuous bios to bio_list before workqueue is scheduled to run. The analysis aligned with above test "3". When system load is high, there is some delay before the workqueue can be scheduled to run, the higher the system load the greater the delay. So there is more chance that the same io submit thread can add multiple continuous bios to bio_list. Then when the workqueue is scheduled to run, there are more continuous bios in bio_list, which will be processed in blkg_async_bio_workfn(). The analysis aligned with above test "1" and "2". According to test, we can get io performance improved with the patch, especially when system load is higher. Another optimazition is to use the plug only when bio_list contains at least 2 bios. Signed-off-by:Xianting Tian <tian.xianting@h3c.com> Signed-off-by:
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Christoph Hellwig authored
Remove the now unused check_disk_change helper. Signed-off-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by:
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Christoph Hellwig authored
Both callers have a valid CD struture available, so rely on that instead of getting another reference. Also move the function to avoid a forward declaration. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call sr_block_revalidate_disk manually. Also add an explicit call to sr_block_revalidate_disk just before disk_add() to ensure we always read check for a ready unit and read the TOC and then stop wiring up ->revalidate_disk. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call sd_revalidate_disk manually. As sd also calls sd_revalidate_disk manually during probe and open, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
The md driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by:
Song Liu <song@kernel.org> Signed-off-by:
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Christoph Hellwig authored
ide-gd is only using the disk events mechanism to be able to force an invalidation and partition scan on opening removable media. Just open code the logic without invoving the block layer. Signed-off-by:
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Christoph Hellwig authored
Just merge the trivial function into its only caller. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_changed instead of check_disk_change and call idecd_revalidate_disk manually. Given that idecd_revalidate_disk only re-reads the TOC, and we already do the same at probe time, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
The Sega GD-ROM driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by:
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Christoph Hellwig authored
The pcd driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by:
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Christoph Hellwig authored
Pass a struct ace_device to ace_revalidate_disk, move the media changed check into the one caller that needs it, and give the routine a better name. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call ace_revalidate_disk manually. Given that ace_revalidate_disk only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_changed instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
floppy_revalidate mostly duplicates work already done in floppy_open despite only beeing called from floppy_open. Remove the function and just clear the ->ejected flag directly under the right condition. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
Switch to use bdev_check_media_change instead of check_disk_change and call floppy_revalidate manually. Given that floppy_revalidate only deals with media change events, the extra call into ->revalidate_disk from bdev_disk_changed is not required either, so stop wiring up the method. Signed-off-by:
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Christoph Hellwig authored
The Amiga floppy driver does not have a ->revalidate_disk method, so it can just use bdev_check_media_change without any additional changes. Signed-off-by:
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Christoph Hellwig authored
Like check_disk_changed, except that it does not call ->revalidate_disk but leaves that to the caller. Signed-off-by:
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- 08 Sep, 2020 5 commits
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Christoph Hellwig authored
Switch to the naming used by the other entries so that we can use the QUEUE_RW_ENTRY helper. Signed-off-by:
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Christoph Hellwig authored
Add two helpers macros to avoid boilerplate code for the queue sysfs entries. Signed-off-by:
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Wang Hai authored
The sparse tool complains as follows: kernel/trace/blktrace.c:796:5: warning: symbol 'blk_trace_bio_get_cgid' was not declared. Should it be static? This function is not used outside of blktrace.c, so this commit marks it static. Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Wang Hai <wanghai38@huawei.com> Signed-off-by:
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Baolin Wang authored
Now we usually free the hctx->sched_data by e->type->ops.exit_hctx(), and no users will use blk_mq_sched_free_hctx_data() function. Remove it. Signed-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by:
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Jan Kara authored
Discarding blocks and buffers under a mounted filesystem is hardly anything admin wants to do. Usually it will confuse the filesystem and sometimes the loss of buffer_head state (including b_private field) can even cause crashes like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G O --------- - - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1 Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015 RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2] ... Call Trace: __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2] jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2] kjournald2+0xbd/0x270 [jbd2] So if we don't have block device open with O_EXCL already, claim the block device while we truncate buffer cache. This makes sure any exclusive block device user (such as filesystem) cannot operate on the device while we are discarding buffer cache. Reported-by:
Ye Bin <yebin10@huawei.com> Signed-off-by:
Jan Kara <jack@suse.cz> Reviewed-by:
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- 07 Sep, 2020 1 commit
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Jan Kara authored
If block_write_full_page() is called for a page that is beyond current inode size, it will truncate page buffers for the page and return 0. This logic has been added in 2.5.62 in commit 81eb6906 ("fix ext3 BUG due to race with truncate") in history.git tree to fix a problem with ext3 in data=ordered mode. This particular problem doesn't exist anymore because ext3 is long gone and ext4 handles ordered data differently. Also normally buffers are invalidated by truncate code and there's no need to specially handle this in ->writepage() code. This invalidation of page buffers in block_write_full_page() is causing issues to filesystems (e.g. ext4 or ocfs2) when block device is shrunk under filesystem's hands and metadata buffers get discarded while being tracked by the journalling layer. Although it is obviously "not supported" it can cause kernel crashes like: [ 7986.689400] BUG: unable to handle kernel NULL pointer dereference at +0000000000000008 [ 7986.697197] PGD 0 P4D 0 [ 7986.699724] Oops: 0002 [#1] SMP PTI [ 7986.703200] CPU: 4 PID: 203778 Comm: jbd2/dm-3-8 Kdump: loaded Tainted: G +O --------- - - 4.18.0-147.5.0.5.h126.eulerosv2r9.x86_64 #1 [ 7986.716438] Hardware name: Huawei RH2288H V3/BC11HGSA0, BIOS 1.57 08/11/2015 [ 7986.723462] RIP: 0010:jbd2_journal_grab_journal_head+0x1b/0x40 [jbd2] ... [ 7986.810150] Call Trace: [ 7986.812595] __jbd2_journal_insert_checkpoint+0x23/0x70 [jbd2] [ 7986.818408] jbd2_journal_commit_transaction+0x155f/0x1b60 [jbd2] [ 7986.836467] kjournald2+0xbd/0x270 [jbd2] which is not great. The crash happens because bh->b_private is suddently NULL although BH_JBD flag is still set (this is because block_invalidatepage() cleared BH_Mapped flag and subsequent bh lookup found buffer without BH_Mapped set, called init_page_buffers() which has rewritten bh->b_private). So just remove the invalidation in block_write_full_page(). Note that the buffer cache invalidation when block device changes size is already careful to avoid similar problems by using invalidate_mapping_pages() which skips busy buffers so it was only this odd block_write_full_page() behavior that could tear down bdev buffers under filesystem's hands. Reported-by:
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- 03 Sep, 2020 10 commits
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Kashyap Desai authored
High CPU utilization on "native_queued_spin_lock_slowpath" due to lock contention is possible for mq-deadline and bfq IO schedulers when nr_hw_queues is more than one. It is because kblockd work queue can submit IO from all online CPUs (through blk_mq_run_hw_queues()) even though only one hctx has pending commands. The elevator callback .has_work for mq-deadline and bfq scheduler considers pending work if there are any IOs on request queue but it does not account hctx context. Add a per-hctx 'elevator_queued' count to the hctx to avoid triggering the elevator even though there are no requests queued. [jpg: Relocated atomic_dec() in dd_dispatch_request(), update commit message per Kashyap] Signed-off-by:
Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by:
John Garry <john.garry@huawei.com> Tested-by:
Douglas Gilbert <dgilbert@interlog.com> Signed-off-by:
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John Garry authored
For when using a shared sbitmap, no longer should the number of active request queues per hctx be relied on for when judging how to share the tag bitmap. Instead maintain the number of active request queues per tag_set, and make the judgement based on that. Originally-from: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by:
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John Garry authored
The per-hctx nr_active value can no longer be used to fairly assign a share of tag depth per request queue for when using a shared sbitmap, as it does not consider that the tags are shared tags over all hctx's. For this case, record the nr_active_requests per request_queue, and make the judgement based on that value. Co-developed-with: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by:
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John Garry authored
blk-mq.h and blk-mq-tag.h include on each other, which is less than ideal. Locate hctx_may_queue() to blk-mq.h, as it is not really tag specific code. In this way, we can drop the blk-mq-tag.h include of blk-mq.h Signed-off-by:
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John Garry authored
Some SCSI HBAs (such as HPSA, megaraid, mpt3sas, hisi_sas_v3 ..) support multiple reply queues with single hostwide tags. In addition, these drivers want to use interrupt assignment in pci_alloc_irq_vectors(PCI_IRQ_AFFINITY). However, as discussed in [0], CPU hotplug may cause in-flight IO completion to not be serviced when an interrupt is shutdown. That problem is solved in commit bf0beec0 ("blk-mq: drain I/O when all CPUs in a hctx are offline"). However, to take advantage of that blk-mq feature, the HBA HW queuess are required to be mapped to that of the blk-mq hctx's; to do that, the HBA HW queues need to be exposed to the upper layer. In making that transition, the per-SCSI command request tags are no longer unique per Scsi host - they are just unique per hctx. As such, the HBA LLDD would have to generate this tag internally, which has a certain performance overhead. However another problem is that blk-mq assumes the host may accept (Scsi_host.can_queue * #hw queue) commands. In commit 6eb045e0 ("scsi: core: avoid host-wide host_busy counter for scsi_mq"), the Scsi host busy counter was removed, which would stop the LLDD being sent more than .can_queue commands; however, it should still be ensured that the block layer does not issue more than .can_queue commands to the Scsi host. To solve this problem, introduce a shared sbitmap per blk_mq_tag_set, which may be requested at init time. New flag BLK_MQ_F_TAG_HCTX_SHARED should be set when requesting the tagset to indicate whether the shared sbitmap should be used. Even when BLK_MQ_F_TAG_HCTX_SHARED is set, a full set of tags and requests are still allocated per hctx; the reason for this is that if tags and requests were only allocated for a single hctx - like hctx0 - it may break block drivers which expect a request be associated with a specific hctx, i.e. not always hctx0. This will introduce extra memory usage. This change is based on work originally from Ming Lei in [1] and from Bart's suggestion in [2]. [0] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [1] https://lore.kernel.org/linux-block/20190531022801.10003-1-ming.lei@redhat.com/ [2] https://lore.kernel.org/linux-block/ff77beff-5fd9-9f05-12b6-826922bace1f@huawei.com/T/#m3db0a602f095cbcbff27e9c884d6b4ae826144beSigned-off-by:
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John Garry authored
Introduce pointers for the blk_mq_tags regular and reserved bitmap tags, with the goal of later being able to use a common shared tag bitmap across all HW contexts in a set. Signed-off-by:
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John Garry authored
Pass hctx/tagset flags argument down to blk_mq_init_tags() and blk_mq_free_tags() for selective init/free. For now, make it include the alloc policy flag, which can be evaluated when needed (in blk_mq_init_tags()). Signed-off-by:
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Hannes Reinecke authored
Since the tags are allocated in blk_mq_init_tags(), it's better practice to free in that same function upon error, rather than a callee which is to init the bitmap tags (blk_mq_init_tags()). [jpg: Split from an earlier patch with a new commit message] Signed-off-by:
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Hannes Reinecke authored
The function does not set the depth, but rather transitions from shared to non-shared queues and vice versa. So rename it to blk_mq_update_tag_set_shared() to better reflect its purpose. [jpg: take out some unrelated changes in blk_mq_init_bitmap_tags()] Signed-off-by:
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Ming Lei authored
BLK_MQ_F_TAG_SHARED actually means that tags is shared among request queues, all of which should belong to LUNs attached to same HBA. So rename it to make the point explicitly. [jpg: rebase a few times, add rnbd-clt.c change] Suggested-by:
Bart Van Assche <bvanassche@acm.org> Signed-off-by:
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