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commit 65fac0d54f374625b43a9d6ad1f2c212bd41f518 upstream.
Currently, in virtio_scsi, if 'bd->last' is not set to true while
dispatching request, such io will stay in driver's queue, and driver
will wait for block layer to dispatch more rqs. However, if block
layer failed to dispatch more rq, it should trigger commit_rqs to
inform driver.
There is a problem in blk_mq_try_issue_list_directly() that commit_rqs
won't be called:
// assume that queue_depth is set to 1, list contains two rq
blk_mq_try_issue_list_directly
blk_mq_request_issue_directly
// dispatch first rq
// last is false
__blk_mq_try_issue_directly
blk_mq_get_dispatch_budget
// succeed to get first budget
__blk_mq_issue_directly
scsi_queue_rq
cmd->flags |= SCMD_LAST
virtscsi_queuecommand
kick = (sc->flags & SCMD_LAST) != 0
// kick is false, first rq won't issue to disk
queued++
blk_mq_request_issue_directly
// dispatch second rq
__blk_mq_try_issue_directly
blk_mq_get_dispatch_budget
// failed to get second budget
ret == BLK_STS_RESOURCE
blk_mq_request_bypass_insert
// errors is still 0
if (!list_empty(list) || errors && ...)
// won't pass, commit_rqs won't be called
In this situation, first rq relied on second rq to dispatch, while
second rq relied on first rq to complete, thus they will both hung.
Fix the problem by also treat 'BLK_STS_*RESOURCE' as 'errors' since
it means that request is not queued successfully.
Same problem exists in blk_mq_dispatch_rq_list(), 'BLK_STS_*RESOURCE'
can't be treated as 'errors' here, fix the problem by calling
commit_rqs if queue_rq return 'BLK_STS_*RESOURCE'.
Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220726122224.1790882-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 14dc7a18abbe4176f5626c13c333670da8e06aa1 ]
This patch prevents that test nvme/004 triggers the following:
UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9
index 512 is out of range for type 'long unsigned int [512]'
Call Trace:
show_stack+0x52/0x58
dump_stack_lvl+0x49/0x5e
dump_stack+0x10/0x12
ubsan_epilogue+0x9/0x3b
__ubsan_handle_out_of_bounds.cold+0x44/0x49
blk_mq_alloc_request_hctx+0x304/0x310
__nvme_submit_sync_cmd+0x70/0x200 [nvme_core]
nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics]
nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop]
nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop]
nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics]
nvmf_dev_write+0xae/0x111 [nvme_fabrics]
vfs_write+0x144/0x560
ksys_write+0xb7/0x140
__x64_sys_write+0x42/0x50
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Fixes: 20e4d8139319 ("blk-mq: simplify queue mapping & schedule with each possisble CPU")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220615210004.1031820-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 5d05426e2d5fd7df8afc866b78c36b37b00188b7 ]
blk_mq_run_hw_queues() could be run when there isn't queued request and
after queue is cleaned up, at that time tagset is freed, because tagset
lifetime is covered by driver, and often freed after blk_cleanup_queue()
returns.
So don't touch ->tagset for figuring out current default hctx by the mapping
built in request queue, so use-after-free on tagset can be avoided. Meantime
this way should be fast than retrieving mapping from tagset.
Cc: "yukuai (C)" <yukuai3@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Fixes: b6e68ee82585 ("blk-mq: Improve performance of non-mq IO schedulers with multiple HW queues")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220522122350.743103-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 2a19b28f7929866e1cec92a3619f4de9f2d20005 upstream.
For avoiding to slow down queue destroy, we don't call
blk_mq_quiesce_queue() in blk_cleanup_queue(), instead of delaying to
cancel dispatch work in blk_release_queue().
However, this way has caused kernel oops[1], reported by Changhui. The log
shows that scsi_device can be freed before running blk_release_queue(),
which is expected too since scsi_device is released after the scsi disk
is closed and the scsi_device is removed.
Fixes the issue by canceling blk-mq dispatch work in both blk_cleanup_queue()
and disk_release():
1) when disk_release() is run, the disk has been closed, and any sync
dispatch activities have been done, so canceling dispatch work is enough to
quiesce filesystem I/O dispatch activity.
2) in blk_cleanup_queue(), we only focus on passthrough request, and
passthrough request is always explicitly allocated & freed by
its caller, so once queue is frozen, all sync dispatch activity
for passthrough request has been done, then it is enough to just cancel
dispatch work for avoiding any dispatch activity.
[1] kernel panic log
[12622.769416] BUG: kernel NULL pointer dereference, address: 0000000000000300
[12622.777186] #PF: supervisor read access in kernel mode
[12622.782918] #PF: error_code(0x0000) - not-present page
[12622.788649] PGD 0 P4D 0
[12622.791474] Oops: 0000 [#1] PREEMPT SMP PTI
[12622.796138] CPU: 10 PID: 744 Comm: kworker/10:1H Kdump: loaded Not tainted 5.15.0+ #1
[12622.804877] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS 1.5.4 10/002/2015
[12622.813321] Workqueue: kblockd blk_mq_run_work_fn
[12622.818572] RIP: 0010:sbitmap_get+0x75/0x190
[12622.823336] Code: 85 80 00 00 00 41 8b 57 08 85 d2 0f 84 b1 00 00 00 45 31 e4 48 63 cd 48 8d 1c 49 48 c1 e3 06 49 03 5f 10 4c 8d 6b 40 83 f0 01 <48> 8b 33 44 89 f2 4c 89 ef 0f b6 c8 e8 fa f3 ff ff 83 f8 ff 75 58
[12622.844290] RSP: 0018:ffffb00a446dbd40 EFLAGS: 00010202
[12622.850120] RAX: 0000000000000001 RBX: 0000000000000300 RCX: 0000000000000004
[12622.858082] RDX: 0000000000000006 RSI: 0000000000000082 RDI: ffffa0b7a2dfe030
[12622.866042] RBP: 0000000000000004 R08: 0000000000000001 R09: ffffa0b742721334
[12622.874003] R10: 0000000000000008 R11: 0000000000000008 R12: 0000000000000000
[12622.881964] R13: 0000000000000340 R14: 0000000000000000 R15: ffffa0b7a2dfe030
[12622.889926] FS: 0000000000000000(0000) GS:ffffa0baafb40000(0000) knlGS:0000000000000000
[12622.898956] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[12622.905367] CR2: 0000000000000300 CR3: 0000000641210001 CR4: 00000000001706e0
[12622.913328] Call Trace:
[12622.916055] <TASK>
[12622.918394] scsi_mq_get_budget+0x1a/0x110
[12622.922969] __blk_mq_do_dispatch_sched+0x1d4/0x320
[12622.928404] ? pick_next_task_fair+0x39/0x390
[12622.933268] __blk_mq_sched_dispatch_requests+0xf4/0x140
[12622.939194] blk_mq_sched_dispatch_requests+0x30/0x60
[12622.944829] __blk_mq_run_hw_queue+0x30/0xa0
[12622.949593] process_one_work+0x1e8/0x3c0
[12622.954059] worker_thread+0x50/0x3b0
[12622.958144] ? rescuer_thread+0x370/0x370
[12622.962616] kthread+0x158/0x180
[12622.966218] ? set_kthread_struct+0x40/0x40
[12622.970884] ret_from_fork+0x22/0x30
[12622.974875] </TASK>
[12622.977309] Modules linked in: scsi_debug rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs sunrpc dm_multipath intel_rapl_msr intel_rapl_common dell_wmi_descriptor sb_edac rfkill video x86_pkg_temp_thermal intel_powerclamp dcdbas coretemp kvm_intel kvm mgag200 irqbypass i2c_algo_bit rapl drm_kms_helper ipmi_ssif intel_cstate intel_uncore syscopyarea sysfillrect sysimgblt fb_sys_fops pcspkr cec mei_me lpc_ich mei ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter drm fuse xfs libcrc32c sr_mod cdrom sd_mod t10_pi sg ixgbe ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata megaraid_sas ghash_clmulni_intel tg3 wdat_wdt mdio dca wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_debug]
Reported-by: ChanghuiZhong <czhong@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211116014343.610501-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 037057a5a979c7eeb2ee5d12cf4c24b805192c75 ]
This check is meant to catch cases where a requeue is attempted on a
request that is still inserted. It's never really been useful to catch any
misuse, and now it's actively wrong. Outside of that, this should not be a
BUG_ON() to begin with.
Remove the check as it's now causing active harm, as requeue off the plug
path will trigger it even though the request state is just fine.
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Link: https://lore.kernel.org/linux-block/CAHj4cs80zAUc2grnCZ015-2Rvd-=gXRfB_dFKy=RTm+wRo09HQ@mail.gmail.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ba0ffdd8ce48ad7f7e85191cd29f9674caca3745 ]
Particularly for NVMe with efficient deferred submission for many
requests, there are nice benefits to be seen by bumping the default max
plug count from 16 to 32. This is especially true for virtualized setups,
where the submit part is more expensive. But can be noticed even on
native hardware.
Reduce the multiple queue factor from 4 to 2, since we're changing the
default size.
While changing it, move the defines into the block layer private header.
These aren't values that anyone outside of the block layer uses, or
should use.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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When dispatching a zone append write request to a SCSI zoned block device,
if the target zone of the request is already locked, the device driver will
return BLK_STS_ZONE_RESOURCE and the request will be pushed back to the
hctx dipatch queue. The queue will be marked as RESTART in
dd_finish_request() and restarted in __blk_mq_free_request(). However, this
restart applies to the hctx of the completed request. If the requeued
request is on a different hctx, dispatch will no be retried until another
request is submitted or the next periodic queue run triggers, leading to up
to 30 seconds latency for the requeued request.
Fix this problem by scheduling a queue restart similarly to the
BLK_STS_RESOURCE case or when we cannot get the budget.
Also, consolidate the checks into the "need_resource" variable to simplify
the condition.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Niklas Cassel <Niklas.Cassel@wdc.com>
Link: https://lore.kernel.org/r/20211026165127.4151055-1-naohiro.aota@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Don't switch back to percpu mode to avoid the double RCU grace period
when tearing down SCSI devices. After removing the disk only passthrough
commands can be send anyway.
Suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20210929071241.934472-6-hch@lst.de
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph:
- fix nvmet command set reporting for passthrough controllers (Adam Manzanares)
- update a MAINTAINERS email address (Chaitanya Kulkarni)
- set QUEUE_FLAG_NOWAIT for nvme-multipth (me)
- handle errors from add_disk() (Luis Chamberlain)
- update the keep alive interval when kato is modified (Tatsuya Sasaki)
- fix a buffer overrun in nvmet_subsys_attr_serial (Hannes Reinecke)
- do not reset transport on data digest errors in nvme-tcp (Daniel Wagner)
- only call synchronize_srcu when clearing current path (Daniel Wagner)
- revalidate paths during rescan (Hannes Reinecke)
- Split out the fs/block_dev into block/fops.c and block/bdev.c, which
has been long overdue. Do this now before -rc1, to avoid annoying
conflicts due to this (Christoph)
- blk-throtl use-after-free fix (Li)
- Improve plug depth for multi-device plugs, greatly increasing md
resync performance (Song)
- blkdev_show() locking fix (Tetsuo)
- n64cart error check fix (Yang)
* tag 'block-5.15-2021-09-11' of git://git.kernel.dk/linux-block:
n64cart: fix return value check in n64cart_probe()
blk-mq: allow 4x BLK_MAX_REQUEST_COUNT at blk_plug for multiple_queues
block: move fs/block_dev.c to block/bdev.c
block: split out operations on block special files
blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()
block: genhd: don't call blkdev_show() with major_names_lock held
nvme: update MAINTAINERS email address
nvme: add error handling support for add_disk()
nvme: only call synchronize_srcu when clearing current path
nvme: update keep alive interval when kato is modified
nvme-tcp: Do not reset transport on data digest errors
nvmet: fixup buffer overrun in nvmet_subsys_attr_serial()
nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req
nvmet: looks at the passthrough controller when initializing CAP
nvme: move nvme_multi_css into nvme.h
nvme-multipath: revalidate paths during rescan
nvme-multipath: set QUEUE_FLAG_NOWAIT
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Limiting number of request to BLK_MAX_REQUEST_COUNT at blk_plug hurts
performance for large md arrays. [1] shows resync speed of md array drops
for md array with more than 16 HDDs.
Fix this by allowing more request at plug queue. The multiple_queue flag
is used to only apply higher limit to multiple queue cases.
[1] https://lore.kernel.org/linux-raid/CAFDAVznS71BXW8Jxv6k9dXc2iR3ysX3iZRBww_rzA8WifBFxGg@mail.gmail.com/
Tested-by: Marcin Wanat <marcin.wanat@gmail.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull SCSI updates from James Bottomley:
"This series consists of the usual driver updates (ufs, qla2xxx,
target, smartpqi, lpfc, mpt3sas).
The core change causing the most churn was replacing the command
request field request with a macro, allowing us to offset map to it
and remove the redundant field; the same was also done for the tag
field.
The most impactful change is the final removal of scsi_ioctl, which
has been deprecated for over a decade"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (293 commits)
scsi: ufs: Fix ufshcd_request_sense_async() for Samsung KLUFG8RHDA-B2D1
scsi: ufs: ufs-exynos: Fix static checker warning
scsi: mpt3sas: Use the proper SCSI midlayer interfaces for PI
scsi: lpfc: Use the proper SCSI midlayer interfaces for PI
scsi: lpfc: Copyright updates for 14.0.0.1 patches
scsi: lpfc: Update lpfc version to 14.0.0.1
scsi: lpfc: Add bsg support for retrieving adapter cmf data
scsi: lpfc: Add cmf_info sysfs entry
scsi: lpfc: Add debugfs support for cm framework buffers
scsi: lpfc: Add support for maintaining the cm statistics buffer
scsi: lpfc: Add rx monitoring statistics
scsi: lpfc: Add support for the CM framework
scsi: lpfc: Add cmfsync WQE support
scsi: lpfc: Add support for cm enablement buffer
scsi: lpfc: Add cm statistics buffer support
scsi: lpfc: Add EDC ELS support
scsi: lpfc: Expand FPIN and RDF receive logging
scsi: lpfc: Add MIB feature enablement support
scsi: lpfc: Add SET_HOST_DATA mbox cmd to pass date/time info to firmware
scsi: fc: Add EDC ELS definition
...
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Pull block updates from Jens Axboe:
"Nothing major in here - lots of good cleanups and tech debt handling,
which is also evident in the diffstats. In particular:
- Add disk sequence numbers (Matteo)
- Discard merge fix (Ming)
- Relax disk zoned reporting restrictions (Niklas)
- Bio error handling zoned leak fix (Pavel)
- Start of proper add_disk() error handling (Luis, Christoph)
- blk crypto fix (Eric)
- Non-standard GPT location support (Dmitry)
- IO priority improvements and cleanups (Damien)o
- blk-throtl improvements (Chunguang)
- diskstats_show() stack reduction (Abd-Alrhman)
- Loop scheduler selection (Bart)
- Switch block layer to use kmap_local_page() (Christoph)
- Remove obsolete disk_name helper (Christoph)
- block_device refcounting improvements (Christoph)
- Ensure gendisk always has a request queue reference (Christoph)
- Misc fixes/cleanups (Shaokun, Oliver, Guoqing)"
* tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block: (129 commits)
sg: pass the device name to blk_trace_setup
block, bfq: cleanup the repeated declaration
blk-crypto: fix check for too-large dun_bytes
blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN
blk-zoned: allow zone management send operations without CAP_SYS_ADMIN
block: mark blkdev_fsync static
block: refine the disk_live check in del_gendisk
mmc: sdhci-tegra: Enable MMC_CAP2_ALT_GPT_TEGRA
mmc: block: Support alternative_gpt_sector() operation
partitions/efi: Support non-standard GPT location
block: Add alternative_gpt_sector() operation
bio: fix page leak bio_add_hw_page failure
block: remove CONFIG_DEBUG_BLOCK_EXT_DEVT
block: remove a pointless call to MINOR() in device_add_disk
null_blk: add error handling support for add_disk()
virtio_blk: add error handling support for add_disk()
block: add error handling for device_add_disk / add_disk
block: return errors from disk_alloc_events
block: return errors from blk_integrity_add
block: call blk_register_queue earlier in device_add_disk
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"Updates to the interrupt core and driver subsystems:
Core changes:
- The usual set of small fixes and improvements all over the place,
but nothing stands out
MSI changes:
- Further consolidation of the PCI/MSI interrupt chip code
- Make MSI sysfs code independent of PCI/MSI and expose the MSI
interrupts of platform devices in the same way as PCI exposes them.
Driver changes:
- Support for ARM GICv3 EPPI partitions
- Treewide conversion to generic_handle_domain_irq() for all chained
interrupt controllers
- Conversion to bitmap_zalloc() throughout the irq chip drivers
- The usual set of small fixes and improvements"
* tag 'irq-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
platform-msi: Add ABI to show msi_irqs of platform devices
genirq/msi: Move MSI sysfs handling from PCI to MSI core
genirq/cpuhotplug: Demote debug printk to KERN_DEBUG
irqchip/qcom-pdc: Trim unused levels of the interrupt hierarchy
irqdomain: Export irq_domain_disconnect_hierarchy()
irqchip/gic-v3: Fix priority comparison when non-secure priorities are used
irqchip/apple-aic: Fix irq_disable from within irq handlers
pinctrl/rockchip: drop the gpio related codes
gpio/rockchip: drop irq_gc_lock/irq_gc_unlock for irq set type
gpio/rockchip: support next version gpio controller
gpio/rockchip: use struct rockchip_gpio_regs for gpio controller
gpio/rockchip: add driver for rockchip gpio
dt-bindings: gpio: change items restriction of clock for rockchip,gpio-bank
pinctrl/rockchip: add pinctrl device to gpio bank struct
pinctrl/rockchip: separate struct rockchip_pin_bank to a head file
pinctrl/rockchip: always enable clock for gpio controller
genirq: Fix kernel doc indentation
EDAC/altera: Convert to generic_handle_domain_irq()
powerpc: Bulk conversion to generic_handle_domain_irq()
nios2: Bulk conversion to generic_handle_domain_irq()
...
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Replace the magic lookup through the kobject tree with an explicit
backpointer, given that the device model links are set up and torn
down at times when I/O is still possible, leading to potential
NULL or invalid pointer dereferences.
Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk")
Reported-by: syzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pass in a request_queue and assign disk->queue in __blk_alloc_disk to
ensure struct gendisk always has a valid ->queue pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This was a leftover from the legacy alloc_disk interface. Switch
the scsi ULPs and dasd to set ->minors directly like all other
drivers and remove the argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com> [dasd]
Link: https://lore.kernel.org/r/20210816131910.615153-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pass the lockdep name to the low-level __blk_alloc_disk helper and
hardcode the name for it given that the number of minors or node_id
are not very useful information. While this passes a pointless
argument for non-lockdep builds that is not really an issue as
disk allocation is a probe time only slow path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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is_flush_rq() is called from bt_iter()/bt_tags_iter(), and runs the
following check:
hctx->fq->flush_rq == req
but the passed hctx from bt_iter()/bt_tags_iter() may be NULL because:
1) memory re-order in blk_mq_rq_ctx_init():
rq->mq_hctx = data->hctx;
...
refcount_set(&rq->ref, 1);
OR
2) tag re-use and ->rqs[] isn't updated with new request.
Fix the issue by re-writing is_flush_rq() as:
return rq->end_io == flush_end_io;
which turns out simpler to follow and immune to data race since we have
ordered WRITE rq->end_io and refcount_set(&rq->ref, 1).
Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter")
Cc: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de>
Cc: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210818010925.607383-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Inside blk_mq_queue_tag_busy_iter() we already grabbed request's
refcount before calling ->fn(), so needn't to grab it one more time
in blk_mq_check_expired().
Meantime remove extra request expire check in blk_mq_check_expired().
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20210811155202.629575-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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We run a test that delete and recover devcies frequently(two devices on
the same host), and we found that 'active_queues' is super big after a
period of time.
If device a and device b share a tag set, and a is deleted, then
blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
is only one queue that are using the tag set. However, if b is still
active, the active_queues of b might never be cleared even if b is
deleted.
Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210731062130.1533893-1-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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With CONFIG_IRQ_FORCED_THREADING=y, testing the boolean force_irqthreads
could incur a cache line miss in invoke_softirq() and other places.
Replace the test with a static key to avoid the potential cache miss.
[ tglx: Dropped the IDE part, removed the export and updated blk-mq ]
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tanner Love <tannerlove@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210602180338.3324213-1-tannerlove.kernel@gmail.com
|
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The backing device information only makes sense for file system I/O,
and thus belongs into the gendisk and not the lower level request_queue
structure. Move it there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Move the sg_timeout and sg_reserved_size fields into the bsg_device and
scsi_device structures as they have nothing to do with generic block I/O.
Note that these values are now separate for bsg vs. SCSI device node
access, but that just matches how /dev/sg vs the other nodes has always
behaved.
Link: https://lore.kernel.org/r/20210729064845.1044147-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
|
|
All driver uses are gone now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210624081012.256464-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Pull core block updates from Jens Axboe:
- disk events cleanup (Christoph)
- gendisk and request queue allocation simplifications (Christoph)
- bdev_disk_changed cleanups (Christoph)
- IO priority improvements (Bart)
- Chained bio completion trace fix (Edward)
- blk-wbt fixes (Jan)
- blk-wbt enable/disable fix (Zhang)
- Scheduler dispatch improvements (Jan, Ming)
- Shared tagset scheduler improvements (John)
- BFQ updates (Paolo, Luca, Pietro)
- BFQ lock inversion fix (Jan)
- Documentation improvements (Kir)
- CLONE_IO block cgroup fix (Tejun)
- Remove of ancient and deprecated block dump feature (zhangyi)
- Discard merge fix (Ming)
- Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
Yang)
* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
block: fix discard request merge
block/mq-deadline: Remove a WARN_ON_ONCE() call
blk-mq: update hctx->dispatch_busy in case of real scheduler
blk: Fix lock inversion between ioc lock and bfqd lock
bfq: Remove merged request already in bfq_requests_merged()
block: pass a gendisk to bdev_disk_changed
block: move bdev_disk_changed
block: add the events* attributes to disk_attrs
block: move the disk events code to a separate file
block: fix trace completion for chained bio
block/partitions/msdos: Fix typo inidicator -> indicator
block, bfq: reset waker pointer with shared queues
block, bfq: check waker only for queues with no in-flight I/O
block, bfq: avoid delayed merge of async queues
block, bfq: boost throughput by extending queue-merging times
block, bfq: consider also creation time in delayed stable merge
block, bfq: fix delayed stable merge check
block, bfq: let also stably merged queues enjoy weight raising
blk-wbt: make sure throttle is enabled properly
blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
...
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Commit 6e6fcbc27e77 ("blk-mq: support batching dispatch in case of io")
starts to support io batching submission by using hctx->dispatch_busy.
However, blk_mq_update_dispatch_busy() isn't changed to update hctx->dispatch_busy
in that commit, so fix the issue by updating hctx->dispatch_busy in case
of real scheduler.
Reported-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Fixes: 6e6fcbc27e77 ("blk-mq: support batching dispatch in case of io")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210625020248.1630497-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_ONCE/WRITE_ONCE as appropriate.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
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Remove yet another few p->state accesses.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.347475156@infradead.org
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Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
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All users are gone now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Add a new API to allocate a gendisk including the request_queue for use
with blk-mq based drivers. This is to avoid boilerplate code in drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Don't return the passed in request_queue but a normal error code, and
drop the elevator_init argument in favor of just calling elevator_init_mq
directly from dm-rq.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Factour out a helper to initialize a simple single hw queue tag_set from
blk_mq_init_sq_queue. This will allow to phase out blk_mq_init_sq_queue
in favor of a more symmetric and general API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Provided the device driver does not implement dispatch budget accounting
(which only SCSI does) the loop in __blk_mq_do_dispatch_sched() pulls
requests from the IO scheduler as long as it is willing to give out any.
That defeats scheduling heuristics inside the scheduler by creating
false impression that the device can take more IO when it in fact
cannot.
For example with BFQ IO scheduler on top of virtio-blk device setting
blkio cgroup weight has barely any impact on observed throughput of
async IO because __blk_mq_do_dispatch_sched() always sucks out all the
IO queued in BFQ. BFQ first submits IO from higher weight cgroups but
when that is all dispatched, it will give out IO of lower weight cgroups
as well. And then we have to wait for all this IO to be dispatched to
the disk (which means lot of it actually has to complete) before the
IO scheduler is queried again for dispatching more requests. This
completely destroys any service differentiation.
So grab request tag for a request pulled out of the IO scheduler already
in __blk_mq_do_dispatch_sched() and do not pull any more requests if we
cannot get it because we are unlikely to be able to dispatch it. That
way only single request is going to wait in the dispatch list for some
tag to free.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210603104721.6309-1-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The tags used for an IO scheduler are currently per hctx.
As such, when q->nr_hw_queues grows, so does the request queue total IO
scheduler tag depth.
This may cause problems for SCSI MQ HBAs whose total driver depth is
fixed.
Ming and Yanhui report higher CPU usage and lower throughput in scenarios
where the fixed total driver tag depth is appreciably lower than the total
scheduler tag depth:
https://lore.kernel.org/linux-block/440dfcfc-1a2c-bd98-1161-cec4d78c6dfc@huawei.com/T/#mc0d6d4f95275a2743d1c8c3e4dc9ff6c9aa3a76b
In that scenario, since the scheduler tag is got first, much contention
is introduced since a driver tag may not be available after we have got
the sched tag.
Improve this scenario by introducing request queue-wide tags for when
a tagset-wide sbitmap is used. The static sched requests are still
allocated per hctx, as requests are initialised per hctx, as in
blk_mq_init_request(..., hctx_idx, ...) ->
set->ops->init_request(.., hctx_idx, ...).
For simplicity of resizing the request queue sbitmap when updating the
request queue depth, just init at the max possible size, so we don't need
to deal with the possibly with swapping out a new sbitmap for old if
we need to grow.
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1620907258-30910-3-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The tag allocation code to alloc the sbitmap pairs is common for regular
bitmaps tags and shared sbitmap, so refactor into a common function.
Also remove superfluous "flags" argument from blk_mq_init_shared_sbitmap().
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1620907258-30910-2-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Before we free request queue, clearing flush request reference in
tags->rqs[], so that potential UAF can be avoided.
Based on one patch written by David Jeffery.
Tested-by: John Garry <john.garry@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210511152236.763464-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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refcount_inc_not_zero() in bt_tags_iter() still may read one freed
request.
Fix the issue by the following approach:
1) hold a per-tags spinlock when reading ->rqs[tag] and calling
refcount_inc_not_zero in bt_tags_iter()
2) clearing stale request referred via ->rqs[tag] before freeing
request pool, the per-tags spinlock is held for clearing stale
->rq[tag]
So after we cleared stale requests, bt_tags_iter() won't observe
freed request any more, also the clearing will wait for pending
request reference.
The idea of clearing ->rqs[] is borrowed from John Garry's previous
patch and one recent David's patch.
Tested-by: John Garry <john.garry@huawei.com>
Reviewed-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210511152236.763464-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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|
Grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter(), and
this way will prevent the request from being re-used when ->fn is
running. The approach is same as what we do during handling timeout.
Fix request use-after-free(UAF) related with completion race or queue
releasing:
- If one rq is referred before rq->q is frozen, then queue won't be
frozen before the request is released during iteration.
- If one rq is referred after rq->q is frozen, refcount_inc_not_zero()
will return false, and we won't iterate over this request.
However, still one request UAF not covered: refcount_inc_not_zero() may
read one freed request, and it will be handled in next patch.
Tested-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210511152236.763464-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If a tag set is shared across request queues (e.g. SCSI LUNs) then the
block layer core keeps track of the number of active request queues in
tags->active_queues. blk_mq_tag_busy() and blk_mq_tag_idle() update that
atomic counter if the hctx flag BLK_MQ_F_TAG_QUEUE_SHARED is set. Make
sure that blk_mq_exit_queue() calls blk_mq_tag_idle() before that flag is
cleared by blk_mq_del_queue_tag_set().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Fixes: 0d2602ca30e4 ("blk-mq: improve support for shared tags maps")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210513171529.7977-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In case of shared sbitmap, request won't be held in plug list any more
sine commit 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per
tagset"), this way makes request merge from flush plug list & batching
submission not possible, so cause performance regression.
Yanhui reports performance regression when running sequential IO
test(libaio, 16 jobs, 8 depth for each job) in VM, and the VM disk
is emulated with image stored on xfs/megaraid_sas.
Fix the issue by recovering original behavior to allow to hold request
in plug list.
Cc: Yanhui Ma <yama@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: kashyap.desai@broadcom.com
Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514022052.1047665-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull SCSI updates from James Bottomley:
"This consists of the usual driver updates (ufs, target, tcmu,
smartpqi, lpfc, zfcp, qla2xxx, mpt3sas, pm80xx).
The major core change is using a sbitmap instead of an atomic for
queue tracking"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (412 commits)
scsi: target: tcm_fc: Fix a kernel-doc header
scsi: target: Shorten ALUA error messages
scsi: target: Fix two format specifiers
scsi: target: Compare explicitly with SAM_STAT_GOOD
scsi: sd: Introduce a new local variable in sd_check_events()
scsi: dc395x: Open-code status_byte(u8) calls
scsi: 53c700: Open-code status_byte(u8) calls
scsi: smartpqi: Remove unused functions
scsi: qla4xxx: Remove an unused function
scsi: myrs: Remove unused functions
scsi: myrb: Remove unused functions
scsi: mpt3sas: Fix two kernel-doc headers
scsi: fcoe: Suppress a compiler warning
scsi: libfc: Fix a format specifier
scsi: aacraid: Remove an unused function
scsi: core: Introduce enum scsi_disposition
scsi: core: Modify the scsi_send_eh_cmnd() return value for the SDEV_BLOCK case
scsi: core: Rename scsi_softirq_done() into scsi_complete()
scsi: core: Remove an incorrect comment
scsi: core: Make the scsi_alloc_sgtables() documentation more accurate
...
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Pull block updates from Jens Axboe:
"Pretty quiet round this time, which is nice. In detail:
- Series revamping bounce buffer support (Christoph)
- Dead code removal (Christoph, Bart)
- Partition iteration revamp, now using xarray (Christoph)
- Passthrough request scheduler improvements (Lin)
- Series of BFQ improvements (Paolo)
- Fix ioprio task iteration (Peter)
- Various little tweaks and fixes (Tejun, Saravanan, Bhaskar, Max,
Nikolay)"
* tag 'for-5.13/block-2021-04-27' of git://git.kernel.dk/linux-block: (41 commits)
blk-iocost: don't ignore vrate_min on QD contention
blk-mq: Fix spurious debugfs directory creation during initialization
bfq/mq-deadline: remove redundant check for passthrough request
blk-mq: bypass IO scheduler's limit_depth for passthrough request
block: Remove an obsolete comment from sg_io()
block: move bio_list_copy_data to pktcdvd
block: remove zero_fill_bio_iter
block: add queue_to_disk() to get gendisk from request_queue
block: remove an incorrect check from blk_rq_append_bio
block: initialize ret in bdev_disk_changed
block: Fix sys_ioprio_set(.which=IOPRIO_WHO_PGRP) task iteration
block: remove disk_part_iter
block: simplify diskstats_show
block: simplify show_partition
block: simplify printk_all_partitions
block: simplify partition_overlaps
block: simplify partition removal
block: take bd_mutex around delete_partitions in del_gendisk
block: refactor blk_drop_partitions
block: move more syncing and invalidation to delete_partition
...
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Commit 01e99aeca39796003 ("blk-mq: insert passthrough request into
hctx->dispatch directly") gives high priority to passthrough requests and
bypass underlying IO scheduler. But as we allocate tag for such request it
still runs io-scheduler's callback limit_depth, while we really want is to
give full sbitmap-depth capabity to such request for acquiring available
tag.
blktrace shows PC requests(dmraid -s -c -i) hit bfq's limit_depth:
8,0 2 0 0.000000000 39952 1,0 m N bfq [bfq_limit_depth] wr_busy 0 sync 0 depth 8
8,0 2 1 0.000008134 39952 D R 4 [dmraid]
8,0 2 2 0.000021538 24 C R [0]
8,0 2 0 0.000035442 39952 1,0 m N bfq [bfq_limit_depth] wr_busy 0 sync 0 depth 8
8,0 2 3 0.000038813 39952 D R 24 [dmraid]
8,0 2 4 0.000044356 24 C R [0]
This patch introduce a new wrapper to make code not that ugly.
Signed-off-by: Lin Feng <linf@wangsu.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210415033920.213963-1-linf@wangsu.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.
Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
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SCSI uses a global atomic variable to track queue depth for each
LUN/request queue.
This doesn't scale well when there are lots of CPU cores and the disk is
very fast. It has been observed that IOPS is affected a lot by tracking
queue depth via sdev->device_busy in the I/O path.
Return budget token from .get_budget callback. The budget token can be
passed to driver so that we can replace the atomic variable with
sbitmap_queue and alleviate the scaling problems that way.
Link: https://lore.kernel.org/r/20210122023317.687987-9-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Allocation hint should have belonged to sbitmap. Also, when sbitmap's depth
is high and there is no need to use mulitple wakeup queues, user can
benefit from percpu allocation hint too.
Move allocation hint into sbitmap, then SCSI device queue can benefit from
allocation hint when converting to plain sbitmap.
Convert vhost/scsi.c to use sbitmap allocation with percpu alloc hint. This
is more efficient than the previous approach.
Link: https://lore.kernel.org/r/20210122023317.687987-5-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: virtualization@lists.linux-foundation.org
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Currently the allocation round_robin info is maintained by sbitmap_queue.
However, bit allocation really belongs to sbitmap. Move it there.
Link: https://lore.kernel.org/r/20210122023317.687987-3-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: virtualization@lists.linux-foundation.org
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Pull block IPI updates from Jens Axboe:
"Avoid IRQ locking for the block IPI handling (Sebastian Andrzej
Siewior)"
* tag 'for-5.12/block-ipi-2021-02-21' of git://git.kernel.dk/linux-block:
blk-mq: Use llist_head for blk_cpu_done
blk-mq: Always complete remote completions requests in softirq
smp: Process pending softirqs in flush_smp_call_function_from_idle()
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With llist_head it is possible to avoid the locking (the irq-off region)
when items are added. This makes it possible to add items on a remote
CPU without additional locking.
llist_add() returns true if the list was previously empty. This can be
used to invoke the SMP function call / raise sofirq only if the first
item was added (otherwise it is already pending).
This simplifies the code a little and reduces the IRQ-off regions.
blk_mq_raise_softirq() needs a preempt-disable section to ensure the
request is enqueued on the same CPU as the softirq is raised.
Some callers (USB-storage) invoke this path in preemptible context.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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