Commit Graph

441 Commits

Author SHA1 Message Date
Ming Lei
e63a573035 blk-cgroup: bypass blkcg_deactivate_policy after destroying
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>
2023-11-17 10:48:58 -07:00
Linus Torvalds
3d3dfeb3ae for-6.6/block-2023-08-28
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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
  ...
2023-08-29 20:21:42 -07:00
Ming Lei
c164c7bc97 blk-cgroup: hold queue_lock when removing blkg->q_node
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>
2023-08-18 15:00:39 -06:00
Tejun Heo
ec14a87ee1 blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init
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>
2023-08-17 19:21:05 -06:00
Jens Axboe
3a08284ff2 Merge branch 'for-6.5/block-late' into block-6.5
* 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()
2023-06-28 16:08:19 -06:00
Linus Torvalds
a0433f8cae for-6.5/block-2023-06-23
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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
  ...
2023-06-26 12:47:20 -07:00
Jinke Han
ad7c3b41e8 blk-throttle: Fix io statistics for cgroup v1
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>
2023-06-25 08:00:39 -06:00
Ming Lei
9c39b7a905 block: make sure local irq is disabled when calling __blkcg_rstat_flush
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>
2023-06-22 07:44:00 -06:00
Ming Lei
20cb1c2fb7 blk-cgroup: Flush stats before releasing blkcg_gq
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>
2023-06-11 19:49:29 -06:00
Waiman Long
3d2af77e31 blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()
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>
2023-06-07 07:51:34 -06:00
Yu Kuai
a13bd91be2 block/rq_qos: protect rq_qos apis with a new lock
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>
2023-05-23 11:13:19 -06:00
Linus Torvalds
a3b111b046 for-6.4/block-2023-05-06
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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()
2023-05-06 08:28:58 -07:00
Tao Su
8176080d59 block: Skip destroyed blkg when restart in blkg_destroy_all()
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>
2023-04-28 11:23:58 -06:00
Linus Torvalds
9dd6956b38 for-6.4/block-2023-04-21
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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
  ...
2023-04-26 12:52:58 -07:00
Christoph Hellwig
2c275afeb6 block: make blkcg_punt_bio_submit optional
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>
2023-04-17 18:01:22 +02:00
Christoph Hellwig
12be09fe18 block: async_bio_lock does not need to be bh-safe
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>
2023-04-17 18:01:22 +02:00
Christoph Hellwig
3480373ebd btrfs, block: move REQ_CGROUP_PUNT to btrfs
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>
2023-04-17 18:01:22 +02:00
Tejun Heo
a13696b83d blk-iolatency: Make initialization lazy
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>
2023-04-13 06:46:49 -06:00
Tejun Heo
faffaab289 blkcg: Restructure blkg_conf_prep() and friends
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>
2023-04-13 06:46:49 -06:00
Tejun Heo
83462a6c97 blkcg: Drop unnecessary RCU read [un]locks from blkg_conf_prep/finish()
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>
2023-04-13 06:46:48 -06:00
Chengming Zhou
650e2cb50f blk-cgroup: delete cpd_init_fn of blkcg_policy
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>
2023-04-06 16:17:32 -06:00
Chengming Zhou
d1023165ee blk-cgroup: delete cpd_bind_fn of blkcg_policy
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>
2023-04-06 16:17:32 -06:00
Linus Torvalds
5b0ed59649 for-6.3/block-2023-02-16
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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
  ...
2023-02-20 14:27:21 -08:00
Christoph Hellwig
a06377c5d0 Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
This reverts commit 84d7d462b1.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230214183308.1658775-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-14 14:24:09 -07:00
Christoph Hellwig
9a9c261e6b Revert "blk-cgroup: pass a gendisk to blkg_lookup"
This reverts commit 821e840c08ad83736eced4037cdad864e95e2584.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230214183308.1658775-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-14 14:24:09 -07:00
Christoph Hellwig
1231039db3 Revert "blk-cgroup: move the cgroup information to struct gendisk"
This reverts commit 3f13ab7c80 as a patch
it depends on caused a few problems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230214183308.1658775-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-14 14:24:09 -07:00
Christoph Hellwig
dcb5220143 Revert "blk-cgroup: simplify blkg freeing from initialization failure paths"
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>
2023-02-09 08:11:11 -07:00
Yu Kuai
f37bf75ca7 block, bfq: cleanup 'bfqg->online'
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>
2023-02-07 10:20:59 -07:00
Christoph Hellwig
28e538a309 blk-cgroup: fix freeing NULL blkg in blkg_create
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>
2023-02-06 08:43:23 -07:00
Christoph Hellwig
3f13ab7c80 blk-cgroup: move the cgroup information to struct gendisk
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
479664cee1 blk-cgroup: pass a gendisk to blkg_lookup
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
0a0b4f79db blk-cgroup: pass a gendisk to pd_alloc_fn
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
40e4996ec0 blk-cgroup: pass a gendisk to blkcg_{de,}activate_policy
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
f05837ed73 blk-cgroup: store a gendisk to throttle in struct task_struct
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
84d7d462b1 blk-cgroup: pin the gendisk in struct blkcg_gq
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
180b04d450 blk-cgroup: remove the !bdi->dev check in blkg_dev_name
bdi_dev_name already performs the same check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
27b642b07a blk-cgroup: simplify blkg freeing from initialization failure paths
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>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
0b6f93bdf0 blk-cgroup: improve error unwinding in blkg_alloc
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>
2023-02-03 08:20:04 -07:00
Ming Lei
0416f3be58 blk-cgroup: don't update io stat for root cgroup
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>
2023-02-01 19:26:41 -07:00
Yu Kuai
f1c006f1c6 blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()
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>
2023-01-29 15:19:04 -07:00
Yu Kuai
dfd6200a09 blk-cgroup: support to track if policy is online
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>
2023-01-29 15:19:04 -07:00
Yu Kuai
c7241babf0 blk-cgroup: dropping parent refcount after pd_free_fn() is done
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>
2023-01-29 15:19:04 -07:00
Yu Kuai
e3ff8887e7 blk-cgroup: fix missing pd_online_fn() while activating policy
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>
2023-01-16 19:04:07 -07:00
Tejun Heo
813e693023 blk-iolatency: Fix memory leak on add_disk() failures
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>
2022-12-14 12:42:55 -07:00
Linus Torvalds
ce8a79d560 for-6.2/block-2022-12-08
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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
  ...
2022-12-13 10:43:59 -08:00
Kemeng Shi
37754595e9 blk-cgroup: Fix typo in comment
Replace assocating with associating.
Replace intiailized with initialized.

Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221206093307.378249-1-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-08 09:17:21 -07:00
Yang Li
1d6df9d352 blk-cgroup: Fix some kernel-doc comments
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>
2022-12-01 18:22:12 -07:00
Jens Axboe
c62256dda3 Revert "blk-cgroup: Flush stats at blkgs destruction path"
This reverts commit dae590a6c9.

We've had a few reports on this causing a crash at boot time, because
of a reference issue. While this problem seemginly did exist before
the patch and needs solving separately, this patch makes it a lot
easier to trigger.

Link: https://lore.kernel.org/linux-block/CA+QYu4oxiRKC6hJ7F27whXy-PRBx=Tvb+-7TQTONN8qTtV3aDA@mail.gmail.com/
Link: https://lore.kernel.org/linux-block/69af7ccb-6901-c84c-0e95-5682ccfb750c@acm.org/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 08:25:46 -07:00
Waiman Long
dae590a6c9 blk-cgroup: Flush stats at blkgs destruction path
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>
2022-11-16 16:58:44 -07:00
Waiman Long
3b8cc62987 blk-cgroup: Optimize blkcg_rstat_flush()
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>
2022-11-16 16:58:44 -07:00