Dennis Zhou (Facebook) 6b06546206 Revert "blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()" ... This reverts commit 4c6994806f. Destroying blkgs is tricky because of the nature of the relationship. A blkg should go away when either a blkcg or a request_queue goes away. However, blkg's pin the blkcg to ensure they remain valid. To break this cycle, when a blkcg is offlined, blkgs put back their css ref. This eventually lets css_free() get called which frees the blkcg. The above commit (4c6994806f) breaks this order of events by trying to destroy blkgs in css_free(). As the blkgs still hold references to the blkcg, css_free() is never called. The race between blkcg_bio_issue_check() and cgroup_rmdir() will be addressed in the following patch by delaying destruction of a blkg until all writeback associated with the blkcg has been finished. Fixes: 4c6994806f ("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2018-08-31 14:48:54 -06:00
..
acpi	ACPICA: Update version to 20180810	2018-08-14 23:49:13 +02:00
asm-generic	mm: mmu_notifier fix for tlb_end_vma	2018-08-23 11:55:58 -07:00
clocksource
crypto	crypto: scatterwalk - remove scatterwalk_samebuf()	2018-08-03 18:06:04 +08:00
drm	drm pull for 4.19-rc1	2018-08-15 17:39:07 -07:00
dt-bindings	ARM: Device-tree updates	2018-08-23 14:02:22 -07:00
keys
kvm	KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIs	2018-08-12 12:06:34 +01:00
linux	Revert "blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()"	2018-08-31 14:48:54 -06:00
math-emu
media	- New Drivers	2018-08-20 15:38:44 -07:00
memory
misc	Revert "cxl: Allow a default context to be associated with an external pci_dev"	2018-07-02 23:54:33 +10:00
net	Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2018-08-21 13:47:29 -07:00
pcmcia	pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function	2018-08-18 12:30:42 -07:00
ras
rdma	Second merge window update	2018-08-23 15:34:48 -07:00
scsi	SCSI misc on 20180815	2018-08-15 22:06:26 -07:00
soc	Various updates to soc/fsl for 4.19	2018-07-26 00:12:56 -07:00
sound	ASoC: Updates for v4.19	2018-08-13 12:12:31 +02:00
target	scsi: target: add session removal function	2018-08-02 15:29:31 -04:00
trace	Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2018-08-24 13:19:27 -07:00
uapi	This pull request contains updates for both UBI and UBIFS:	2018-08-23 15:58:04 -07:00
video	fbdev changes for v4.19:	2018-08-23 15:44:58 -07:00
xen	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2018-08-18 16:48:07 -07:00