linux-stable/block
Carlo Nonato 4db2f87e15 block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()
[ Upstream commit 14afc59361 ]

The bfq_find_set_group() function takes as input a blkcg (which represents
a cgroup) and retrieves the corresponding bfq_group, then it updates the
bfq internal group hierarchy (see comments inside the function for why
this is needed) and finally it returns the bfq_group.
In the hierarchy update cycle, the pointer holding the correct bfq_group
that has to be returned is mistakenly used to traverse the hierarchy
bottom to top, meaning that in each iteration it gets overwritten with the
parent of the current group. Since the update cycle stops at root's
children (depth = 2), the overwrite becomes a problem only if the blkcg
describes a cgroup at a hierarchy level deeper than that (depth > 2). In
this case the root's child that happens to be also an ancestor of the
correct bfq_group is returned. The main consequence is that processes
contained in a cgroup at depth greater than 2 are wrongly placed in the
group described above by BFQ.

This commits fixes this problem by using a different bfq_group pointer in
the update cycle in order to avoid the overwrite of the variable holding
the original group reference.

Reported-by: Kwon Je Oh <kwonje.oh2@gmail.com>
Signed-off-by: Carlo Nonato <carlo.nonato95@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25 08:25:49 +01:00
..
partitions docs: admin-guide: add a series of orphaned documents 2019-07-15 11:03:02 -03:00
badblocks.c block: switch all files cleared marked as GPLv2 to SPDX tags 2019-04-30 16:11:57 -06:00
bfq-cgroup.c block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group() 2020-03-25 08:25:49 +01:00
bfq-iosched.c block, bfq: remove ifdefs from around gets/puts of bfq groups 2020-03-12 13:00:32 +01:00
bfq-iosched.h block, bfq: remove ifdefs from around gets/puts of bfq groups 2020-03-12 13:00:32 +01:00
bfq-wf2q.c block, bfq: get a ref to a group when adding it to a service tree 2020-03-12 13:00:32 +01:00
bio-integrity.c block: fix memleak of bio integrity data 2020-01-26 10:01:09 +01:00
bio.c block: fix memleak of bio integrity data 2020-01-26 10:01:09 +01:00
blk-cgroup.c blkcg: make blkcg_print_stat() print stats only for online blkgs 2019-11-06 17:08:38 -07:00
blk-core.c block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT 2020-01-12 12:21:37 +01:00
blk-exec.c block: add SPDX tags to block layer files missing licensing information 2019-04-30 16:12:03 -06:00
blk-flush.c blk-mq: insert passthrough request into hctx->dispatch directly 2020-03-21 08:11:52 +01:00
blk-integrity.c block: centralize PI remapping logic to the block layer 2019-09-17 20:03:49 -06:00
blk-ioc.c block: remove the queue_lock indirection 2018-11-15 12:17:28 -07:00
blk-iocost.c blk-iocost: fix incorrect vtime comparison in iocg_is_idle() 2020-03-18 07:17:52 +01:00
blk-iolatency.c blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/ 2019-08-28 21:17:08 -06:00
blk-lib.c block: fix 32 bit overflow in __blkdev_issue_discard() 2018-11-14 08:17:18 -07:00
blk-map.c block: fix memleak when __blk_rq_map_user_iov() is failed 2020-01-12 12:21:43 +01:00
blk-merge.c block: Improve physical block alignment of split bios 2019-08-04 21:41:29 -06:00
blk-mq-cpumap.c blk-mq: balance mapping between present CPUs and queues 2019-08-04 21:43:12 -06:00
blk-mq-debugfs-zoned.c block: Cleanup license notice 2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c for-5.3/block-20190708 2019-07-09 10:45:06 -07:00
blk-mq-debugfs.h blk-mq: no need to check return value of debugfs_create functions 2019-06-13 03:00:30 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c blk-mq: insert flush request to the front of dispatch queue 2020-03-21 08:11:57 +01:00
blk-mq-sched.h block: blk-mq: Remove blk_mq_sched_started_request and started_request 2019-07-23 07:25:09 -06:00
blk-mq-sysfs.c blk-mq: make sure that line break can be printed 2019-12-17 19:56:53 +01:00
blk-mq-tag.c blk-mq: introduce blk_mq_tagset_wait_completed_request() 2019-08-04 21:41:29 -06:00
blk-mq-tag.h Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
blk-mq-virtio.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq.c blk-mq: insert passthrough request into hctx->dispatch directly 2020-03-21 08:11:52 +01:00
blk-mq.h blk-mq: insert passthrough request into hctx->dispatch directly 2020-03-21 08:11:52 +01:00
blk-pm.c block: bypass blk_set_runtime_active for uninitialized q->dev 2019-09-12 07:11:56 -06:00
blk-pm.h block: remove the queue_lock indirection 2018-11-15 12:17:28 -07:00
blk-rq-qos.c blk-wbt: fix performance regression in wbt scale_up/scale_down 2019-10-06 09:26:41 -06:00
blk-rq-qos.h blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
blk-settings.c block: fix an integer overflow in logical block size 2020-01-23 08:22:32 +01:00
blk-softirq.c block: remove a few unused exports 2018-11-15 12:13:25 -07:00
blk-stat.c block: add SPDX tags to block layer files missing licensing information 2019-04-30 16:12:03 -06:00
blk-stat.h block: deactivate blk_stat timer in wbt_disable_default() 2018-12-12 06:47:51 -07:00
blk-sysfs.c rq-qos: get rid of redundant wbt_update_limits() 2019-09-27 01:13:10 -06:00
blk-throttle.c block: make rq sector size accessible for block stats 2019-09-15 16:02:08 -06:00
blk-timeout.c block: add SPDX tags to block layer files missing licensing information 2019-04-30 16:12:03 -06:00
blk-wbt.c blk-wbt: fix performance regression in wbt scale_up/scale_down 2019-10-06 09:26:41 -06:00
blk-wbt.h block/rq_qos: implement rq_qos_ops->queue_depth_changed() 2019-08-28 21:17:07 -06:00
blk-zoned.c blk-zoned: implement REQ_OP_ZONE_RESET_ALL 2019-08-04 21:41:29 -06:00
blk.h block: fix memleak of bio integrity data 2020-01-26 10:01:09 +01:00
bounce.c block: remove the i argument to bio_for_each_segment_all 2019-04-30 09:26:13 -06:00
bsg-lib.c block: Fix the type of 'sts' in bsg_queue_rq() 2020-01-23 08:22:44 +01:00
bsg.c block: switch all files cleared marked as GPLv2 to SPDX tags 2019-04-30 16:11:57 -06:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_ioctl.c compat_ioctl: block: handle BLKGETZONESZ/BLKGETNRZONES 2020-01-09 10:19:58 +01:00
elevator.c block: Fix elv_support_iosched() 2019-10-14 13:54:09 -06:00
genhd.c block: Delay default elevator initialization 2019-09-05 19:52:34 -06:00
ioctl.c block: add SPDX tags to block layer files missing licensing information 2019-04-30 16:12:03 -06:00
ioprio.c docs: block: convert to ReST 2019-07-15 09:20:27 -03:00
Kconfig blkcg: implement blk-iocost 2019-08-28 21:17:12 -06:00
Kconfig.iosched docs: block: convert to ReST 2019-07-15 09:20:27 -03:00
kyber-iosched.c blk-mq: remove blk_mq_put_ctx() 2019-07-02 21:03:27 -06:00
Makefile blkcg: implement blk-iocost 2019-08-28 21:17:12 -06:00
mq-deadline.c block: Introduce elevator features 2019-09-05 19:52:33 -06:00
opal_proto.h block: sed-opal: Removed duplicate OPAL_METHOD_LENGTH definition 2019-08-20 09:34:49 -06:00
partition-generic.c block: fix use-after-free on gendisk 2019-04-22 09:48:12 -06:00
scsi_ioctl.c block: switch all files cleared marked as GPLv2 to SPDX tags 2019-04-30 16:11:57 -06:00
sed-opal.c block: sed-opal: fix sparse warning: convert __be64 data 2019-10-03 14:21:32 -06:00
t10-pi.c block: t10-pi: fix -Wswitch warning 2019-09-23 08:05:19 -06:00