blkg_free() can currently be called in atomic context, either spin lock is
held, or run in rcu callback. Meantime either request queue's release
handler or ->pd_free_fn can sleep.
Fix the issue by scheduling a work function for freeing blkcg_gq the
instance.
[ 148.553894] BUG: sleeping function called from invalid context at block/blk-sysfs.c:767
[ 148.557381] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/13
[ 148.560741] preempt_count: 101, expected: 0
[ 148.562577] RCU nest depth: 0, expected: 0
[ 148.564379] 1 lock held by swapper/13/0:
[ 148.566127] #0: ffffffff82615f80 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x0/0x1b
[ 148.569640] Preemption disabled at:
[ 148.569642] [<ffffffff8123f9c3>] ___slab_alloc+0x554/0x661
[ 148.573559] CPU: 13 PID: 0 Comm: swapper/13 Kdump: loaded Not tainted 5.17.0_up+ #110
[ 148.576834] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-1.fc33 04/01/2014
[ 148.579768] Call Trace:
[ 148.580567] <IRQ>
[ 148.581262] dump_stack_lvl+0x56/0x7c
[ 148.582367] ? ___slab_alloc+0x554/0x661
[ 148.583526] __might_resched+0x1af/0x1c8
[ 148.584678] blk_release_queue+0x24/0x109
[ 148.585861] kobject_cleanup+0xc9/0xfe
[ 148.586979] blkg_free+0x46/0x63
[ 148.587962] rcu_do_batch+0x1c5/0x3db
[ 148.589057] rcu_core+0x14a/0x184
[ 148.590065] __do_softirq+0x14d/0x2c7
[ 148.591167] __irq_exit_rcu+0x7a/0xd4
[ 148.592264] sysvec_apic_timer_interrupt+0x82/0xa5
[ 148.593649] </IRQ>
[ 148.594354] <TASK>
[ 148.595058] asm_sysvec_apic_timer_interrupt+0x12/0x20
Cc: Tejun Heo <tj@kernel.org>
Fixes: 0a9a25ca7843 ("block: let blkcg_gq grab request queue's refcnt")
Reported-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-block/20220322093322.GA27283@lst.de/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220323011308.2010380-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Partition include/linux/blk-cgroup.h into two parts: one is public part, the other is block layer private part. Suggested by Christoph Hellwig. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220211101149.2368042-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
No one uses THROTL_IOPS_MAX any more, so remove it. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220211101149.2368042-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
seq_get_buf is a crutch that undoes all the memory safety of the seq_file interface. Use the normal seq_printf interfaces instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210810152623.1796144-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a unique application identifier (i.e fc_app_id member) in blkcg. This allows identification of traffic belonging to an specific both on the host and in the fabric infrastructure. As an example, this allows the storage stack to uniquely identify traffic belong to particular virtual machine. Link: https://lore.kernel.org/r/20210608043556.274139-3-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
To simplify block device lookup and a few other upcoming areas, make sure
that we always have a struct block_device available for each disk and
each partition, and only find existing block devices in bdget. The only
downside of this is that each device and partition uses a little more
memory. The upside will be that a lot of code can be simplified.
With that all we need to look up the block device is to lookup the inode
and do a few sanity checks on the gendisk, instead of the separate lookup
for the gendisk. For blk-cgroup which wants to access a gendisk without
opening it, a new blkdev_{get,put}_no_open low-level interface is added
to replace the previous get_gendisk use.
Note that the change to look up block device directly instead of the two
step lookup using struct gendisk causes a subtile change in behavior:
accessing a non-existing partition on an existing block device can now
cause a call to request_module. That call is harmless, and in practice
no recent system will access these nodes as they aren't created by udev
and static /dev/ setups are unusual.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We never set any congested bits in the group writeback instances of it. And for the simpler bdi-wide case a simple scalar field is all that that is needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkcg_bio_issue_check is a giant inline function that does three entirely different things. Factor out the blk-cgroup related bio initalization into a new helper, and the open code the sequence in the only caller, relying on the fact that all the actual functionality is stubbed out for non-cgroup builds. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only thing in blkcg_bio_issue_check that needs to be under rcu_read_lock is blk_throtl_bio, so move the locking there. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is purely a sanity check for grave programming errors. Remove it to simplify further work in this area. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>