blkcg_deactivate_policy() can be called after blkg_destroy_all()
returns, and it isn't necessary since blkg_destroy_all has covered
policy deactivation.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20231117023527.3188627-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
"Pretty quiet round for this release. This contains:
- Add support for zoned storage to ublk (Andreas, Ming)
- Series improving performance for drivers that mark themselves as
needing a blocking context for issue (Bart)
- Cleanup the flush logic (Chengming)
- sed opal keyring support (Greg)
- Fixes and improvements to the integrity support (Jinyoung)
- Add some exports for bcachefs that we can hopefully delete again in
the future (Kent)
- deadline throttling fix (Zhiguo)
- Series allowing building the kernel without buffer_head support
(Christoph)
- Sanitize the bio page adding flow (Christoph)
- Write back cache fixes (Christoph)
- MD updates via Song:
- Fix perf regression for raid0 large sequential writes (Jan)
- Fix split bio iostat for raid0 (David)
- Various raid1 fixes (Heinz, Xueshi)
- raid6test build fixes (WANG)
- Deprecate bitmap file support (Christoph)
- Fix deadlock with md sync thread (Yu)
- Refactor md io accounting (Yu)
- Various non-urgent fixes (Li, Yu, Jack)
- Various fixes and cleanups (Arnd, Azeem, Chengming, Damien, Li,
Ming, Nitesh, Ruan, Tejun, Thomas, Xu)"
* tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux: (113 commits)
block: use strscpy() to instead of strncpy()
block: sed-opal: keyring support for SED keys
block: sed-opal: Implement IOC_OPAL_REVERT_LSP
block: sed-opal: Implement IOC_OPAL_DISCOVERY
blk-mq: prealloc tags when increase tagset nr_hw_queues
blk-mq: delete redundant tagset map update when fallback
blk-mq: fix tags leak when shrink nr_hw_queues
ublk: zoned: support REQ_OP_ZONE_RESET_ALL
md: raid0: account for split bio in iostat accounting
md/raid0: Fix performance regression for large sequential writes
md/raid0: Factor out helper for mapping and submitting a bio
md raid1: allow writebehind to work on any leg device set WriteMostly
md/raid1: hold the barrier until handle_read_error() finishes
md/raid1: free the r1bio before waiting for blocked rdev
md/raid1: call free_r1bio() before allow_barrier() in raid_end_bio_io()
blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init
drivers/rnbd: restore sysfs interface to rnbd-client
md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
raid6: test: only check for Altivec if building on powerpc hosts
raid6: test: make sure all intermediate and artifact files are .gitignored
...
When blkg is removed from q->blkg_list from blkg_free_workfn(), queue_lock
has to be held, otherwise, all kinds of bugs(list corruption, hard lockup,
..) can be triggered from blkg_destroy_all().
Fixes: f1c006f1c6 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: xiaoli feng <xifeng@redhat.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230817141751.1128970-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-iocost sometimes causes the following crash:
BUG: kernel NULL pointer dereference, address: 00000000000000e0
...
RIP: 0010:_raw_spin_lock+0x17/0x30
Code: be 01 02 00 00 e8 79 38 39 ff 31 d2 89 d0 5d c3 0f 1f 00 0f 1f 44 00 00 55 48 89 e5 65 ff 05 48 d0 34 7e b9 01 00 00 00 31 c0 <f0> 0f b1 0f 75 02 5d c3 89 c6 e8 ea 04 00 00 5d c3 0f 1f 84 00 00
RSP: 0018:ffffc900023b3d40 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 00000000000000e0 RCX: 0000000000000001
RDX: ffffc900023b3d20 RSI: ffffc900023b3cf0 RDI: 00000000000000e0
RBP: ffffc900023b3d40 R08: ffffc900023b3c10 R09: 0000000000000003
R10: 0000000000000064 R11: 000000000000000a R12: ffff888102337000
R13: fffffffffffffff2 R14: ffff88810af408c8 R15: ffff8881070c3600
FS: 00007faaaf364fc0(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000e0 CR3: 00000001097b1000 CR4: 0000000000350ea0
Call Trace:
<TASK>
ioc_weight_write+0x13d/0x410
cgroup_file_write+0x7a/0x130
kernfs_fop_write_iter+0xf5/0x170
vfs_write+0x298/0x370
ksys_write+0x5f/0xb0
__x64_sys_write+0x1b/0x20
do_syscall_64+0x3d/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
This happens because iocg->ioc is NULL. The field is initialized by
ioc_pd_init() and never cleared. The NULL deref is caused by
blkcg_activate_policy() installing blkg_policy_data before initializing it.
blkcg_activate_policy() was doing the following:
1. Allocate pd's for all existing blkg's and install them in blkg->pd[].
2. Initialize all pd's.
3. Online all pd's.
blkcg_activate_policy() only grabs the queue_lock and may release and
re-acquire the lock as allocation may need to sleep. ioc_weight_write()
grabs blkcg->lock and iterates all its blkg's. The two can race and if
ioc_weight_write() runs during #1 or between #1 and #2, it can encounter a
pd which is not initialized yet, leading to crash.
The crash can be reproduced with the following script:
#!/bin/bash
echo +io > /sys/fs/cgroup/cgroup.subtree_control
systemd-run --unit touch-sda --scope dd if=/dev/sda of=/dev/null bs=1M count=1 iflag=direct
echo 100 > /sys/fs/cgroup/system.slice/io.weight
bash -c "echo '8:0 enable=1' > /sys/fs/cgroup/io.cost.qos" &
sleep .2
echo 100 > /sys/fs/cgroup/system.slice/io.weight
with the following patch applied:
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index fc49be622e05..38d671d5e10c 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1553,6 +1553,12 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
> pd->online = false;
> }
>
> + if (system_state == SYSTEM_RUNNING) {
> + spin_unlock_irq(&q->queue_lock);
> + ssleep(1);
> + spin_lock_irq(&q->queue_lock);
> + }
> +
> /* all allocated, init in the same order */
> if (pol->pd_init_fn)
> list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
I don't see a reason why all pd's should be allocated, initialized and
onlined together. The only ordering requirement is that parent blkgs to be
initialized and onlined before children, which is guaranteed from the
walking order. Let's fix the bug by allocating, initializing and onlining pd
for each blkg and holding blkcg->lock over initialization and onlining. This
ensures that an installed blkg is always fully initialized and onlined
removing the the race window.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Breno Leitao <leitao@debian.org>
Fixes: 9d179b8654 ("blkcg: Fix multiple bugs in blkcg_activate_policy()")
Link: https://lore.kernel.org/r/ZN0p5_W-Q9mAHBVY@slm.duckdns.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
* for-6.5/block-late:
blk-sysfs: add a new attr_group for blk_mq
blk-iocost: move wbt_enable/disable_default() out of spinlock
blk-wbt: cleanup rwb_enabled() and wbt_disabled()
blk-wbt: remove dead code to handle wbt enable/disable with io inflight
blk-wbt: don't create wbt sysfs entry if CONFIG_BLK_WBT is disabled
blk-mq: fix two misuses on RQF_USE_SCHED
blk-throttle: Fix io statistics for cgroup v1
bcache: Fix bcache device claiming
bcache: Alloc holder object before async registration
raid10: avoid spin_lock from fastpath from raid10_unplug()
md: fix 'delete_mutex' deadlock
md: use mddev->external to select holder in export_rdev()
md/raid1-10: fix casting from randomized structure in raid1_submit_write()
md/raid10: fix the condition to call bio_end_io_acct()
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Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe pull request via Keith:
- Various cleanups all around (Irvin, Chaitanya, Christophe)
- Better struct packing (Christophe JAILLET)
- Reduce controller error logs for optional commands (Keith)
- Support for >=64KiB block sizes (Daniel Gomez)
- Fabrics fixes and code organization (Max, Chaitanya, Daniel
Wagner)
- bcache updates via Coly:
- Fix a race at init time (Mingzhe Zou)
- Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)
- use page pinning in the block layer for dio (David)
- convert old block dio code to page pinning (David, Christoph)
- cleanups for pktcdvd (Andy)
- cleanups for rnbd (Guoqing)
- use the unchecked __bio_add_page() for the initial single page
additions (Johannes)
- fix overflows in the Amiga partition handling code (Michael)
- improve mq-deadline zoned device support (Bart)
- keep passthrough requests out of the IO schedulers (Christoph, Ming)
- improve support for flush requests, making them less special to deal
with (Christoph)
- add bdev holder ops and shutdown methods (Christoph)
- fix the name_to_dev_t() situation and use cases (Christoph)
- decouple the block open flags from fmode_t (Christoph)
- ublk updates and cleanups, including adding user copy support (Ming)
- BFQ sanity checking (Bart)
- convert brd from radix to xarray (Pankaj)
- constify various structures (Thomas, Ivan)
- more fine grained persistent reservation ioctl capability checks
(Jingbo)
- misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
Jordy, Li, Min, Yu, Zhong, Waiman)
* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
scsi/sg: don't grab scsi host module reference
ext4: Fix warning in blkdev_put()
block: don't return -EINVAL for not found names in devt_from_devname
cdrom: Fix spectre-v1 gadget
block: Improve kernel-doc headers
blk-mq: don't insert passthrough request into sw queue
bsg: make bsg_class a static const structure
ublk: make ublk_chr_class a static const structure
aoe: make aoe_class a static const structure
block/rnbd: make all 'class' structures const
block: fix the exclusive open mask in disk_scan_partitions
block: add overflow checks for Amiga partition support
block: change all __u32 annotations to __be32 in affs_hardblocks.h
block: fix signed int overflow in Amiga partition support
block: add capacity validation in bdev_add_partition()
block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
block: disallow Persistent Reservation on partitions
reiserfs: fix blkdev_put() warning from release_journal_dev()
block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
block: document the holder argument to blkdev_get_by_path
...
After commit f382fb0bce ("block: remove legacy IO schedulers"),
blkio.throttle.io_serviced and blkio.throttle.io_service_bytes become
the only stable io stats interface of cgroup v1, and these statistics
are done in the blk-throttle code. But the current code only counts the
bios that are actually throttled. When the user does not add the throttle
limit, the io stats for cgroup v1 has nothing. I fix it according to the
statistical method of v2, and made it count all ios accurately.
Fixes: a7b36ee6ba ("block: move blk-throtl fast path inline")
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230507170631.89607-1-hanjinke.666@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When __blkcg_rstat_flush() is called from cgroup_rstat_flush*() code
path, interrupt is always disabled.
When we start to flush blkcg per-cpu stats list in __blkg_release()
for avoiding to leak blkcg_gq's reference in commit 20cb1c2fb7
("blk-cgroup: Flush stats before releasing blkcg_gq"), local irq
isn't disabled yet, then lockdep warning may be triggered because
the dependent cgroup locks may be acquired from irq(soft irq) handler.
Fix the issue by disabling local irq always.
Fixes: 20cb1c2fb7 ("blk-cgroup: Flush stats before releasing blkcg_gq")
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/linux-block/pz2wzwnmn5tk3pwpskmjhli6g3qly7eoknilb26of376c7kwxy@qydzpvt6zpis/T/#u
Cc: stable@vger.kernel.org
Cc: Jay Shin <jaeshin@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20230622084249.1208005-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As noted by Michal, the blkg_iostat_set's in the lockless list hold
reference to blkg's to protect against their removal. Those blkg's
hold reference to blkcg. When a cgroup is being destroyed,
cgroup_rstat_flush() is only called at css_release_work_fn() which
is called when the blkcg reference count reaches 0. This circular
dependency will prevent blkcg and some blkgs from being freed after
they are made offline.
It is less a problem if the cgroup to be destroyed also has other
controllers like memory that will call cgroup_rstat_flush() which will
clean up the reference count. If block is the only controller that uses
rstat, these offline blkcg and blkgs may never be freed leaking more
and more memory over time.
To prevent this potential memory leak:
- flush blkcg per-cpu stats list in __blkg_release(), when no new stat
can be added
- add global blkg_stat_lock for covering concurrent parent blkg stat
update
- don't grab bio->bi_blkg reference when adding the stats into blkcg's
per-cpu stat list since all stats are guaranteed to be consumed before
releasing blkg instance, and grabbing blkg reference for stats was the
most fragile part of original patch
Based on Waiman's patch:
https://lore.kernel.org/linux-block/20221215033132.230023-3-longman@redhat.com/
Fixes: 3b8cc62987 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Cc: stable@vger.kernel.org
Reported-by: Jay Shin <jaeshin@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: mkoutny@suse.com
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230609234249.1412858-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When blkg_alloc() is called to allocate a blkcg_gq structure
with the associated blkg_iostat_set's, there are 2 fields within
blkg_iostat_set that requires proper initialization - blkg & sync.
The former field was introduced by commit 3b8cc62987 ("blk-cgroup:
Optimize blkcg_rstat_flush()") while the later one was introduced by
commit f733164829 ("blk-cgroup: reimplement basic IO stats using
cgroup rstat").
Unfortunately those fields in the blkg_iostat_set's are not properly
re-initialized when they are cleared in v1's blkcg_reset_stats(). This
can lead to a kernel panic due to NULL pointer access of the blkg
pointer. The missing initialization of sync is less problematic and
can be a problem in a debug kernel due to missing lockdep initialization.
Fix these problems by re-initializing them after memory clearing.
Fixes: 3b8cc62987 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Fixes: f733164829 ("blk-cgroup: reimplement basic IO stats using cgroup rstat")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230606180724.2455066-1-longman@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
commit 50e34d7881 ("block: disable the elevator int del_gendisk")
move rq_qos_exit() from disk_release() to del_gendisk(), this will
introduce some problems:
1) If rq_qos_add() is triggered by enabling iocost/iolatency through
cgroupfs, then it can concurrent with del_gendisk(), it's not safe to
write 'q->rq_qos' concurrently.
2) Activate cgroup policy that is relied on rq_qos will call
rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is
called in the middle, null-ptr-dereference will be triggered in
blkcg_activate_policy().
3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the
disk, then if rq_qos_exit() from del_gendisk() is done before
rq_qos_add(), then memory will be leaked.
This patch add a new disk level mutex 'rq_qos_mutex':
1) The lock will protect rq_qos_exit() directly.
2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be
called from disk initialization for now because wbt can't be
destructed until rq_qos_exit(), so it's safe not to protect wbt for
now. Hoever, in case that rq_qos dynamically destruction is supported
in the furture, this patch also protect rq_qos_add() from wbt_init()
directly, this is enough because blk-sysfs already synchronize
writers with disk removal.
3) For iocost and iolatency, in order to synchronize disk removal and
cgroup configuration, the lock is held after blkdev_get_no_open()
from blkg_conf_open_bdev(), and is released in blkg_conf_exit().
In order to fix the above memory leak, disk_live() is checked after
holding the new lock.
Fixes: 50e34d7881 ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230414084008.2085155-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux
Pull more block updates from Jens Axboe:
- MD pull request via Song:
- Improve raid5 sequential IO performance on spinning disks, which
fixes a regression since v6.0 (Jan Kara)
- Fix bitmap offset types, which fixes an issue introduced in this
merge window (Jonathan Derrick)
- Cleanup of hweight type used for cgroup writeback (Maxim)
- Fix a regression with the "has_submit_bio" changes across partitions
(Ming)
- Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.
We used to set this flag on queues non blk-mq queues, and hence some
drivers clear it unconditionally. Since all of these have since been
converted to true blk-mq drivers, drop the useless clear as the bit
is not set (Chaitanya)
- Fix the flags being set in a bio for a flush for drbd (Christoph)
- Cleanup and deduplication of the code handling setting block device
capacity (Damien)
- Fix for ublk handling IO timeouts (Ming)
- Fix for a regression in blk-cgroup teardown (Tao)
- NBD documentation and code fixes (Eric)
- Convert blk-integrity to using device_attributes rather than a second
kobject to manage lifetimes (Thomas)
* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
ublk: add timeout handler
drbd: correctly submit flush bio on barrier
mailmap: add mailmap entries for Jens Axboe
block: Skip destroyed blkg when restart in blkg_destroy_all()
writeback: fix call of incorrect macro
md: Fix bitmap offset type in sb writer
md/raid5: Improve performance for sequential IO
docs nbd: userspace NBD now favors github over sourceforge
block nbd: use req.cookie instead of req.handle
uapi nbd: add cookie alias to handle
uapi nbd: improve doc links to userspace spec
blk-integrity: register sysfs attributes on struct device
blk-integrity: convert to struct device_attribute
blk-integrity: use sysfs_emit
block/drivers: remove dead clear of random flag
block: sync part's ->bd_has_submit_bio with disk's
block: Cleanup set_capacity()/bdev_set_nr_sectors()
Kernel hang in blkg_destroy_all() when total blkg greater than
BLKG_DESTROY_BATCH_SIZE, because of not removing destroyed blkg in
blkg_list. So the size of blkg_list is same after destroying a
batch of blkg, and the infinite 'restart' occurs.
Since blkg should stay on the queue list until blkg_free_workfn(),
skip destroyed blkg when restart a new round, which will solve this
kernel hang issue and satisfy the previous will to restart.
Reported-by: Xiangfei Ma <xiangfeix.ma@intel.com>
Tested-by: Xiangfei Ma <xiangfeix.ma@intel.com>
Tested-by: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Fixes: f1c006f1c6 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
Suggested-and-reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20230428045149.1310073-1-tao1.su@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.4/block-2023-04-21' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- drbd patches, bringing us closer to unifying the out-of-tree version
and the in tree one (Andreas, Christoph)
- support for auto-quiesce for the s390 dasd driver (Stefan)
- MD pull request via Song:
- md/bitmap: Optimal last page size (Jon Derrick)
- Various raid10 fixes (Yu Kuai, Li Nan)
- md: add error_handlers for raid0 and linear (Mariusz Tkaczyk)
- NVMe pull request via Christoph:
- Drop redundant pci_enable_pcie_error_reporting (Bjorn Helgaas)
- Validate nvmet module parameters (Chaitanya Kulkarni)
- Fence TCP socket on receive error (Chris Leech)
- Fix async event trace event (Keith Busch)
- Minor cleanups (Chaitanya Kulkarni, zhenwei pi)
- Fix and cleanup nvmet Identify handling (Damien Le Moal,
Christoph Hellwig)
- Fix double blk_mq_complete_request race in the timeout handler
(Lei Yin)
- Fix irq locking in nvme-fcloop (Ming Lei)
- Remove queue mapping helper for rdma devices (Sagi Grimberg)
- use structured request attribute checks for nbd (Jakub)
- fix blk-crypto race conditions between keyslot management (Eric)
- add sed-opal support for reading read locking range attributes
(Ondrej)
- make fault injection configurable for null_blk (Akinobu)
- clean up the request insertion API (Christoph)
- clean up the queue running API (Christoph)
- blkg config helper cleanups (Tejun)
- lazy init support for blk-iolatency (Tejun)
- various fixes and tweaks to ublk (Ming)
- remove hybrid polling. It hasn't really been useful since we got
async polled IO support, and these days we don't support sync polled
IO at all (Keith)
- misc fixes, cleanups, improvements (Zhong, Ondrej, Colin, Chengming,
Chaitanya, me)
* tag 'for-6.4/block-2023-04-21' of git://git.kernel.dk/linux: (118 commits)
nbd: fix incomplete validation of ioctl arg
ublk: don't return 0 in case of any failure
sed-opal: geometry feature reporting command
null_blk: Always check queue mode setting from configfs
block: ublk: switch to ioctl command encoding
blk-mq: fix the blk_mq_add_to_requeue_list call in blk_kick_flush
block, bfq: Fix division by zero error on zero wsum
fault-inject: fix build error when FAULT_INJECTION_CONFIGFS=y and CONFIGFS_FS=m
block: store bdev->bd_disk->fops->submit_bio state in bdev
block: re-arrange the struct block_device fields for better layout
md/raid5: remove unused working_disks variable
md/raid10: don't call bio_start_io_acct twice for bio which experienced read error
md/raid10: fix memleak of md thread
md/raid10: fix memleak for 'conf->bio_split'
md/raid10: fix leak of 'r10bio->remaining' for recovery
md/raid10: don't BUG_ON() in raise_barrier()
md: fix soft lockup in status_resync
md: add error_handlers for raid0 and linear
md: Use optimal I/O size for last bitmap page
md: Fix types in sb writer
...
Guard all the code to punt bios to a per-cgroup submission helper by a
new CONFIG_BLK_CGROUP_PUNT_BIO symbol that is selected by btrfs.
This way non-btrfs kernel builds don't need to have this code.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
async_bio_lock is only taken from bio submission and workqueue context,
both are never in bottom halves.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
REQ_CGROUP_PUNT is a bit annoying as it is hard to follow and adds
a branch to the bio submission hot path. To fix this, export
blkcg_punt_bio_submit and let btrfs call it directly. Add a new
REQ_FS_PRIVATE flag for btrfs to indicate to it's own low-level
bio submission code that a punt to the cgroup submission helper
is required.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Other rq_qos policies such as wbt and iocost are lazy-initialized when they
are configured for the first time for the device but iolatency is
initialized unconditionally from blkcg_init_disk() during gendisk init. Lazy
init is beneficial because rq_qos policies add runtime overhead when
initialized as every IO has to walk all registered rq_qos callbacks.
This patch switches iolatency to lazy initialization too so that it only
registered its rq_qos policy when it is first configured.
Note that there is a known race condition between blkcg config file writes
and del_gendisk() and this patch makes iolatency susceptible to it by
exposing the init path to race against the deletion path. However, that
problem already exists in iocost and is being worked on.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20230413000649.115785-5-tj@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We want to support lazy init of rq-qos policies so that iolatency is enabled
lazily on configuration instead of gendisk initialization. The way blkg
config helpers are structured now is a bit awkward for that. Let's
restructure:
* blkcg_conf_open_bdev() is renamed to blkg_conf_open_bdev(). The blkcg_
prefix was used because the bdev opening step is blkg-independent.
However, the distinction is too subtle and confuses more than helps. Let's
switch to blkg prefix so that it's consistent with the type and other
helper names.
* struct blkg_conf_ctx now remembers the original input string and is always
initialized by the new blkg_conf_init().
* blkg_conf_open_bdev() is updated to take a pointer to blkg_conf_ctx like
blkg_conf_prep() and can be called multiple times safely. Instead of
modifying the double pointer to input string directly,
blkg_conf_open_bdev() now sets blkg_conf_ctx->body.
* blkg_conf_finish() is renamed to blkg_conf_exit() for symmetry and now
must be called on all blkg_conf_ctx's which were initialized with
blkg_conf_init().
Combined, this allows the users to either open the bdev first or do it
altogether with blkg_conf_prep() which will help implementing lazy init of
rq-qos policies.
blkg_conf_init/exit() will also be used implement synchronization against
device removal. This is necessary because iolat / iocost are configured
through cgroupfs instead of one of the files under /sys/block/DEVICE. As
cgroupfs operations aren't synchronized with block layer, the lazy init and
other configuration operations may race against device removal. This patch
makes blkg_conf_init/exit() used consistently for all cgroup-orginating
configurations making them a good place to implement explicit
synchronization.
Users are updated accordingly. No behavior change is intended by this patch.
v2: bfq wasn't updated in v1 causing a build error. Fixed.
v3: Update the description to include future use of blkg_conf_init/exit() as
synchronization points.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yu Kuai <yukuai1@huaweicloud.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230413000649.115785-3-tj@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that all RCU flavors have been combined either holding a spin lock,
disabling irq or disabling preemption implies RCU read lock, so there's no
need to use rcu_read_[un]lock() explicitly while holding queue_lock. This
shouldn't cause any behavior changes.
v2: Description updated. Leave __acquires/release on queue_lock alone.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230413000649.115785-2-tj@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkcg_policy cpd_init_fn() is used to just initialize some default
fields of policy data, which is enough to do in cpd_alloc_fn().
This patch delete the only user bfq_cpd_init(), and remove cpd_init_fn
from blkcg_policy.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230406145050.49914-4-zhouchengming@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
cpd_bind_fn is just used for update default weight when block
subsys attached to a hierarchy. No any policy need it anymore.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230406145050.49914-3-zhouchengming@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe updates via Christoph:
- Small improvements to the logging functionality (Amit Engel)
- Authentication cleanups (Hannes Reinecke)
- Cleanup and optimize the DMA mapping cod in the PCIe driver
(Keith Busch)
- Work around the command effects for Format NVM (Keith Busch)
- Misc cleanups (Keith Busch, Christoph Hellwig)
- Fix and cleanup freeing single sgl (Keith Busch)
- MD updates via Song:
- Fix a rare crash during the takeover process
- Don't update recovery_cp when curr_resync is ACTIVE
- Free writes_pending in md_stop
- Change active_io to percpu
- Updates to drbd, inching us closer to unifying the out-of-tree driver
with the in-tree one (Andreas, Christoph, Lars, Robert)
- BFQ update adding support for multi-actuator drives (Paolo, Federico,
Davide)
- Make brd compliant with REQ_NOWAIT (me)
- Fix for IOPOLL and queue entering, fixing stalled IO waiting on
timeouts (me)
- Fix for REQ_NOWAIT with multiple bios (me)
- Fix memory leak in blktrace cleanup (Greg)
- Clean up sbitmap and fix a potential hang (Kemeng)
- Clean up some bits in BFQ, and fix a bug in the request injection
(Kemeng)
- Clean up the request allocation and issue code, and fix some bugs
related to that (Kemeng)
- ublk updates and fixes:
- Add support for unprivileged ublk (Ming)
- Improve device deletion handling (Ming)
- Misc (Liu, Ziyang)
- s390 dasd fixes (Alexander, Qiheng)
- Improve utility of request caching and fixes (Anuj, Xiao)
- zoned cleanups (Pankaj)
- More constification for kobjs (Thomas)
- blk-iocost cleanups (Yu)
- Remove bio splitting from drivers that don't need it (Christoph)
- Switch blk-cgroups to use struct gendisk. Some of this is now
incomplete as select late reverts were done. (Christoph)
- Add bvec initialization helpers, and convert callers to use that
rather than open-coding it (Christoph)
- Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin,
Matthew, Ulf, Zhong)
* tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits)
brd: use radix_tree_maybe_preload instead of radix_tree_preload
block: use proper return value from bio_failfast()
block: bio-integrity: Copy flags when bio_integrity_payload is cloned
block: Fix io statistics for cgroup in throttle path
brd: mark as nowait compatible
brd: check for REQ_NOWAIT and set correct page allocation mask
brd: return 0/-error from brd_insert_page()
block: sync mixed merged request's failfast with 1st bio's
Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
Revert "blk-cgroup: pass a gendisk to blkg_lookup"
Revert "blk-cgroup: delay blk-cgroup initialization until add_disk"
Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release"
Revert "blk-cgroup: move the cgroup information to struct gendisk"
nvme-pci: remove iod use_sgls
nvme-pci: fix freeing single sgl
block: ublk: check IO buffer based on flag need_get_data
s390/dasd: Fix potential memleak in dasd_eckd_init()
s390/dasd: sort out physical vs virtual pointers usage
block: Remove the ALLOC_CACHE_SLACK constant
block: make kobj_type structures constant
...
It turns out this was too soon. blkg_conf_prep does to funky locking games
with the queue lock for this to work properly.
This reverts commit 27b642b07a.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230209053523.437927-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After commit dfd6200a09 ("blk-cgroup: support to track if policy is
online"), there is no need to do this again in bfq.
However, 'pd->online' is not protected by 'bfqd->lock', in order to make
sure bfq won't see that 'pd->online' is still set after bfq_pd_offline(),
clear it before bfq_pd_offline() is called. This is fine because other
polices doesn't use 'pd->online' and bfq_pd_offline() will move active
bfqq to root cgroup anyway.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230202134913.2364549-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
new_blkg can be NULL if the caller didn't pass in a pre-allocated blkg.
Don't try to free it in that case.
Fixes: 27b642b07a ("blk-cgroup: simplify blkg freeing from initialization failure paths")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230206150201.3438972-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
cgroup information only makes sense on a live gendisk that allows
file system I/O (which includes the raw block device). So move over
the cgroup related members.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a gendisk to blkg_lookup and use that to find the match as part
of phasing out usage of the request_queue in the blk-cgroup code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No need to the request_queue here, pass a gendisk and extract the
node ids from that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Prepare for storing the blkcg information in the gendisk instead of
the request_queue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch from a request_queue pointer and reference to a gendisk once
for the throttle information in struct task_struct.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Link: https://lore.kernel.org/r/20230203150400.3199230-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently each blkcg_gq holds a request_queue reference, which is what
is used in the policies. But a lot of these interfaces will move over to
use a gendisk, so store a disk in struct blkcg_gq and hold a reference to
it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no need to delay freeing a blkg to a workqueue when freeing it
after an initialization failure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Unwind only the previous initialization steps that happened in blkg_alloc
using goto based unwinding. This avoids the need for the !queue special
case in blkg_free and thus ensures that any blkg seens outside of
blkg_alloc is always fully constructed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We source root cgroup stats from the system-wide stats, see blkcg_print_stat
and blkcg_rstat_flush, so don't update io state for root cgroup.
Fixes blkg leak issue introduced in commit 3b8cc62987 ("blk-cgroup: Optimize blkcg_rstat_flush()")
which starts to grab blkg's reference when adding iostat_cpu into percpu
blkcg list, but this state won't be consumed by blkcg_rstat_flush() where
the blkg reference is dropped.
Tested-by: Bart van Assche <bvanassche@acm.org>
Reported-by: Bart van Assche <bvanassche@acm.org>
Fixes: 3b8cc62987 ("blk-cgroup: Optimize blkcg_rstat_flush()")
Cc: Tejun Heo <tj@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230202021804.278582-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently parent pd can be freed before child pd:
t1: remove cgroup C1
blkcg_destroy_blkgs
blkg_destroy
list_del_init(&blkg->q_node)
// remove blkg from queue list
percpu_ref_kill(&blkg->refcnt)
blkg_release
call_rcu
t2: from t1
__blkg_release
blkg_free
schedule_work
t4: deactivate policy
blkcg_deactivate_policy
pd_free_fn
// parent of C1 is freed first
t3: from t2
blkg_free_workfn
pd_free_fn
If policy(for example, ioc_timer_fn() from iocost) access parent pd from
child pd after pd_offline_fn(), then UAF can be triggered.
Fix the problem by delaying 'list_del_init(&blkg->q_node)' from
blkg_destroy() to blkg_free_workfn(), and using a new disk level mutex to
synchronize blkg_free_workfn() and blkcg_deactivate_policy().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230119110350.2287325-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A new field 'online' is added to blkg_policy_data to fix following
2 problem:
1) In blkcg_activate_policy(), if pd_alloc_fn() with 'GFP_NOWAIT'
failed, 'queue_lock' will be dropped and pd_alloc_fn() will try again
without 'GFP_NOWAIT'. In the meantime, remove cgroup can race with
it, and pd_offline_fn() will be called without pd_init_fn() and
pd_online_fn(). This way null-ptr-deference can be triggered.
2) In order to synchronize pd_free_fn() from blkg_free_workfn() and
blkcg_deactivate_policy(), 'list_del_init(&blkg->q_node)' will be
delayed to blkg_free_workfn(), hence pd_offline_fn() can be called
first in blkg_destroy(), and then blkcg_deactivate_policy() will
call it again, we must prevent it.
The new field 'online' will be set after pd_online_fn() and will be
cleared after pd_offline_fn(), in the meantime pd_offline_fn() will only
be called if 'online' is set.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230119110350.2287325-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some cgroup policies will access parent pd through child pd even
after pd_offline_fn() is done. If pd_free_fn() for parent is called
before child, then UAF can be triggered. Hence it's better to guarantee
the order of pd_free_fn().
Currently refcount of parent blkg is dropped in __blkg_release(), which
is before pd_free_fn() is called in blkg_free_work_fn() while
blkg_free_work_fn() is called asynchronously.
This patch make sure pd_free_fn() called from removing cgroup is ordered
by delaying dropping parent refcount after calling pd_free_fn() for
child.
BTW, pd_free_fn() will also be called from blkcg_deactivate_policy()
from deleting device, and following patches will guarantee the order.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230119110350.2287325-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If the policy defines pd_online_fn(), it should be called after
pd_init_fn(), like blkg_create().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230103112833.2013432-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When a gendisk is successfully initialized but add_disk() fails such as when
a loop device has invalid number of minor device numbers specified,
blkcg_init_disk() is called during init and then blkcg_exit_disk() during
error handling. Unfortunately, iolatency gets initialized in the former but
doesn't get cleaned up in the latter.
This is because, in non-error cases, the cleanup is performed by
del_gendisk() calling rq_qos_exit(), the assumption being that rq_qos
policies, iolatency being one of them, can only be activated once the disk
is fully registered and visible. That assumption is true for wbt and iocost,
but not so for iolatency as it gets initialized before add_disk() is called.
It is desirable to lazy-init rq_qos policies because they are optional
features and add to hot path overhead once initialized - each IO has to walk
all the registered rq_qos policies. So, we want to switch iolatency to lazy
init too. However, that's a bigger change. As a fix for the immediate
problem, let's just add an extra call to rq_qos_exit() in blkcg_exit_disk().
This is safe because duplicate calls to rq_qos_exit() become noop's.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: darklight2357@icloud.com
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: d706751215 ("block: introduce blk-iolatency io controller")
Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/Y5TQ5gm3O4HXrXR3@slm.duckdns.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe pull requests via Christoph:
- Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
Joshi)
- Refactor PCIe probing and reset (Christoph Hellwig)
- Various fabrics authentication fixes and improvements (Sagi
Grimberg)
- Avoid fallback to sequential scan due to transient issues (Uday
Shankar)
- Implement support for the DEAC bit in Write Zeroes (Christoph
Hellwig)
- Allow overriding the IEEE OUI and firmware revision in configfs
for nvmet (Aleksandr Miloserdov)
- Force reconnect when number of queue changes in nvmet (Daniel
Wagner)
- Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
Grimberg, Christoph Hellwig, Christophe JAILLET)
- Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
- Use the common tagset helpers in nvme-pci driver (Christoph
Hellwig)
- Cleanup the nvme-pci removal path (Christoph Hellwig)
- Use kstrtobool() instead of strtobool (Christophe JAILLET)
- Allow unprivileged passthrough of Identify Controller (Joel
Granados)
- Support io stats on the mpath device (Sagi Grimberg)
- Minor nvmet cleanup (Sagi Grimberg)
- MD pull requests via Song:
- Code cleanups (Christoph)
- Various fixes
- Floppy pull request from Denis:
- Fix a memory leak in the init error path (Yuan)
- Series fixing some batch wakeup issues with sbitmap (Gabriel)
- Removal of the pktcdvd driver that was deprecated more than 5 years
ago, and subsequent removal of the devnode callback in struct
block_device_operations as no users are now left (Greg)
- Fix for partition read on an exclusively opened bdev (Jan)
- Series of elevator API cleanups (Jinlong, Christoph)
- Series of fixes and cleanups for blk-iocost (Kemeng)
- Series of fixes and cleanups for blk-throttle (Kemeng)
- Series adding concurrent support for sync queues in BFQ (Yu)
- Series bringing drbd a bit closer to the out-of-tree maintained
version (Christian, Joel, Lars, Philipp)
- Misc drbd fixes (Wang)
- blk-wbt fixes and tweaks for enable/disable (Yu)
- Fixes for mq-deadline for zoned devices (Damien)
- Add support for read-only and offline zones for null_blk
(Shin'ichiro)
- Series fixing the delayed holder tracking, as used by DM (Yu,
Christoph)
- Series enabling bio alloc caching for IRQ based IO (Pavel)
- Series enabling userspace peer-to-peer DMA (Logan)
- BFQ waker fixes (Khazhismel)
- Series fixing elevator refcount issues (Christoph, Jinlong)
- Series cleaning up references around queue destruction (Christoph)
- Series doing quiesce by tagset, enabling cleanups in drivers
(Christoph, Chao)
- Series untangling the queue kobject and queue references (Christoph)
- Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)
* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
blktrace: Fix output non-blktrace event when blk_classic option enabled
block: sed-opal: Don't include <linux/kernel.h>
sed-opal: allow using IOC_OPAL_SAVE for locking too
blk-cgroup: Fix typo in comment
block: remove bio_set_op_attrs
nvmet: don't open-code NVME_NS_ATTR_RO enumeration
nvme-pci: use the tagset alloc/free helpers
nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
nvme: consolidate setting the tagset flags
nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
block: bio_copy_data_iter
nvme-pci: split out a nvme_pci_ctrl_is_dead helper
nvme-pci: return early on ctrl state mismatch in nvme_reset_work
nvme-pci: rename nvme_disable_io_queues
nvme-pci: cleanup nvme_suspend_queue
nvme-pci: remove nvme_pci_disable
nvme-pci: remove nvme_disable_admin_queue
nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
nvme: use nvme_wait_ready in nvme_shutdown_ctrl
...
Make the description of @gendisk to @disk in blkcg_schedule_throttle()
to clear the below warnings:
block/blk-cgroup.c:1850: warning: Function parameter or member 'disk' not described in 'blkcg_schedule_throttle'
block/blk-cgroup.c:1850: warning: Excess function parameter 'gendisk' description in 'blkcg_schedule_throttle'
Fixes: de185b56e8 ("blk-cgroup: pass a gendisk to blkcg_schedule_throttle")
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3338
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221202011713.14834-1-yang.lee@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As noted by Michal, the blkg_iostat_set's in the lockless list
hold reference to blkg's to protect against their removal. Those
blkg's hold reference to blkcg. When a cgroup is being destroyed,
cgroup_rstat_flush() is only called at css_release_work_fn() which is
called when the blkcg reference count reaches 0. This circular dependency
will prevent blkcg from being freed until some other events cause
cgroup_rstat_flush() to be called to flush out the pending blkcg stats.
To prevent this delayed blkcg removal, add a new cgroup_rstat_css_flush()
function to flush stats for a given css and cpu and call it at the blkgs
destruction path, blkcg_destroy_blkgs(), whenever there are still some
pending stats to be flushed. This will ensure that blkcg reference
count can reach 0 ASAP.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221105005902.407297-4-longman@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For a system with many CPUs and block devices, the time to do
blkcg_rstat_flush() from cgroup_rstat_flush() can be rather long. It
can be especially problematic as interrupt is disabled during the flush.
It was reported that it might take seconds to complete in some extreme
cases leading to hard lockup messages.
As it is likely that not all the percpu blkg_iostat_set's has been
updated since the last flush, those stale blkg_iostat_set's don't need
to be flushed in this case. This patch optimizes blkcg_rstat_flush()
by keeping a lockless list of recently updated blkg_iostat_set's in a
newly added percpu blkcg->lhead pointer.
The blkg_iostat_set is added to a lockless list on the update side
in blk_cgroup_bio_start(). It is removed from the lockless list when
flushed in blkcg_rstat_flush(). Due to racing, it is possible that
blk_iostat_set's in the lockless list may have no new IO stats to be
flushed, but that is OK.
To protect against destruction of blkg, a percpu reference is gotten
when putting into the lockless list and put back when removed.
When booting up an instrumented test kernel with this patch on a
2-socket 96-thread system with cgroup v2, out of the 2051 calls to
cgroup_rstat_flush() after bootup, 1788 of the calls were exited
immediately because of empty lockless list. After an all-cpu kernel
build, the ratio became 6295424/6340513. That was more than 99%.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20221105005902.407297-3-longman@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
