Jinlong Chen 8ed40ee35d block: fix up elevator_type refcounting ... The current reference management logic of io scheduler modules contains refcnt problems. For example, blk_mq_init_sched may fail before or after the calling of e->ops.init_sched. If it fails before the calling, it does nothing to the reference to the io scheduler module. But if it fails after the calling, it releases the reference by calling kobject_put(&eq->kobj). As the callers of blk_mq_init_sched can't know exactly where the failure happens, they can't handle the reference to the io scheduler module properly: releasing the reference on failure results in double-release if blk_mq_init_sched has released it, and not releasing the reference results in ghost reference if blk_mq_init_sched did not release it either. The same problem also exists in io schedulers' init_sched implementations. We can address the problem by adding releasing statements to the error handling procedures of blk_mq_init_sched and init_sched implementations. But that is counterintuitive and requires modifications to existing io schedulers. Instead, We make elevator_alloc get the io scheduler module references that will be released by elevator_release. And then, we match each elevator_get with an elevator_put. Therefore, each reference to an io scheduler module explicitly has its own getter and releaser, and we no longer need to worry about the refcnt problems. The bugs and the patch can be validated with tools here: https://github.com/nickyc975/linux_elv_refcnt_bug.git [hch: split out a few bits into separate patches, use a non-try module_get in elevator_alloc] Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221020064819.1469928-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>		2022-10-23 18:59:17 -06:00
..
partitions	block: don't add partitions if GD_SUPPRESS_PART_SCAN is set	2022-09-03 11:29:03 -06:00
badblocks.c	block/badblocks: Remove redundant assignments	2022-04-23 07:15:26 -06:00
bdev.c	vfs: support STATX_DIOALIGN on block devices	2022-09-11 19:47:12 -05:00
bfq-cgroup.c	block, bfq: remove unused functions	2022-08-22 10:07:56 -06:00
bfq-iosched.c	blk-wbt: don't enable throttling if default elevator is bfq	2022-10-23 18:59:17 -06:00
bfq-iosched.h	block, bfq: remove unused variable for bfq_queue	2022-10-20 05:46:49 -07:00
bfq-wf2q.c	block, bfq: remove useless parameter for bfq_add/del_bfqq_busy()	2022-08-22 10:07:56 -06:00
bio-integrity.c	block: pass struct queue_limits to the bio splitting helpers	2022-08-02 21:08:53 -06:00
bio.c	block-6.1-2022-10-20	2022-10-21 15:14:14 -07:00
blk-cgroup-fc-appid.c	cgroup: Homogenize cgroup_get_from_id() return value	2022-08-26 10:57:41 -10:00
blk-cgroup-rwstat.c	blk-cgroup: Fix the recursive blkg rwstat	2021-03-05 11:32:15 -07:00
blk-cgroup-rwstat.h	block: Use the new blk_opf_t type	2022-07-14 12:14:30 -06:00
blk-cgroup.c	blk-cgroup: don't update the blkg lookup hint in blkg_conf_prep	2022-09-27 11:50:05 -06:00
blk-cgroup.h	blk-cgroup: pass a gendisk to blkcg_init_queue and blkcg_exit_queue	2022-09-26 19:09:31 -06:00
blk-core.c	for-6.1/block-2022-10-03	2022-10-07 09:19:14 -07:00
blk-crypto-fallback.c	treewide: use get_random_bytes() when possible	2022-10-11 17:42:58 -06:00
blk-crypto-internal.h	blk-crypto: show crypto capabilities in sysfs	2022-02-28 06:40:23 -07:00
blk-crypto-profile.c	blk-crypto: remove blk_crypto_unregister()	2021-11-29 06:38:51 -07:00
blk-crypto-sysfs.c	blk-crypto: show crypto capabilities in sysfs	2022-02-28 06:40:23 -07:00
blk-crypto.c	blk-crypto: show crypto capabilities in sysfs	2022-02-28 06:40:23 -07:00
blk-flush.c	block: change request end_io handler to pass back a return value	2022-09-30 07:49:09 -06:00
blk-ia-ranges.c	block: simplify disk_set_independent_access_ranges	2022-06-29 08:36:46 -06:00
blk-integrity.c	blk-crypto: remove blk_crypto_unregister()	2021-11-29 06:38:51 -07:00
blk-ioc.c	block: fix default IO priority handling again	2022-06-27 06:29:12 -06:00
blk-iocost.c	blk-iocost: read 'ioc->params' inside 'ioc->lock' in ioc_timer_fn()	2022-10-23 18:59:17 -06:00
blk-iolatency.c	blk-cgroup: pass a gendisk to blkcg_schedule_throttle	2022-09-26 19:17:28 -06:00
blk-ioprio.c	blk-ioprio: pass a gendisk to blk_ioprio_init and blk_ioprio_exit	2022-09-26 19:09:31 -06:00
blk-ioprio.h	blk-ioprio: pass a gendisk to blk_ioprio_init and blk_ioprio_exit	2022-09-26 19:09:31 -06:00
blk-lib.c	blk-lib: fix blkdev_issue_secure_erase	2022-09-15 00:25:17 -06:00
blk-map.c	block: extend functionality to map bvec iterator	2022-09-30 07:51:13 -06:00
blk-merge.c	block: pass struct queue_limits to the bio splitting helpers	2022-08-02 21:08:53 -06:00
blk-mq-cpumap.c	block: Change the return type of blk_mq_map_queues() into void	2022-08-22 10:07:53 -06:00
blk-mq-debugfs-zoned.c	block: move zone related fields to struct gendisk	2022-07-06 06:46:26 -06:00
blk-mq-debugfs.c	for-6.1/block-2022-10-03	2022-10-07 09:19:14 -07:00
blk-mq-debugfs.h	block: remove per-disk debugfs files in blk_unregister_queue	2022-06-17 07:31:05 -06:00
blk-mq-pci.c	block: Change the return type of blk_mq_map_queues() into void	2022-08-22 10:07:53 -06:00
blk-mq-rdma.c	block: Change the return type of blk_mq_map_queues() into void	2022-08-22 10:07:53 -06:00
blk-mq-sched.c	block: fix up elevator_type refcounting	2022-10-23 18:59:17 -06:00
blk-mq-sched.h	block: move blk_mq_sched_assign_ioc to blk-ioc.c	2021-11-29 06:41:29 -07:00
blk-mq-sysfs.c	blk-mq: cleanup disk sysfs registration	2022-06-28 11:32:42 -06:00
blk-mq-tag.c	sbitmap: fix batched wait_cnt accounting	2022-09-12 00:10:34 -06:00
blk-mq-tag.h	blk-mq: blk_mq_tag_busy is no need to return a value	2022-06-27 06:29:12 -06:00
blk-mq-virtio.c	block: Change the return type of blk_mq_map_queues() into void	2022-08-22 10:07:53 -06:00
blk-mq.c	block: fix up elevator_type refcounting	2022-10-23 18:59:17 -06:00
blk-mq.h	block: adapt blk_mq_plug() to not plug for writes that require a zone lock	2022-09-29 07:45:47 -06:00
blk-pm.c	scsi: block: pm: Always set request queue runtime active in blk_post_runtime_resume()	2021-12-22 23:38:29 -05:00
blk-pm.h	block: Remove unused blk_pm_*() function definitions	2021-02-22 06:33:48 -07:00
blk-rq-qos.c	block/rq_qos: Use atomic_try_cmpxchg in atomic_inc_below	2022-07-12 14:38:52 -06:00
blk-rq-qos.h	block/blk-rq-qos: delete useless enmu RQ_QOS_IOPRIO	2022-09-21 19:50:53 -06:00
blk-settings.c	block: pass a gendisk to blk_queue_clear_zone_settings	2022-07-06 06:46:26 -06:00
blk-stat.c	block: make queue stat accounting a reference	2021-12-14 17:23:05 -07:00
blk-stat.h	block: make queue stat accounting a reference	2021-12-14 17:23:05 -07:00
blk-sysfs.c	blk-wbt: don't show valid wbt_lat_usec in sysfs while wbt is disabled	2022-10-23 18:59:17 -06:00
blk-throttle.c	blk-throttle: pass a gendisk to blk_throtl_cancel_bios	2022-09-26 19:17:28 -06:00
blk-throttle.h	blk-throttle: pass a gendisk to blk_throtl_cancel_bios	2022-09-26 19:17:28 -06:00
blk-timeout.c	block: blk-timeout: delete duplicated word	2020-07-31 16:29:47 -06:00
blk-wbt.c	blk-wbt: don't enable throttling if default elevator is bfq	2022-10-23 18:59:17 -06:00
blk-wbt.h	blk-wbt: don't show valid wbt_lat_usec in sysfs while wbt is disabled	2022-10-23 18:59:17 -06:00
blk-zoned.c	block: adapt blk_mq_plug() to not plug for writes that require a zone lock	2022-09-29 07:45:47 -06:00
blk.h	- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in	2022-10-10 17:53:04 -07:00
bounce.c	block: change the blk_queue_bounce calling convention	2022-08-02 17:22:54 -06:00
bsg-lib.c	blk-mq: Drop blk_mq_ops.timeout 'reserved' arg	2022-07-06 06:33:53 -06:00
bsg.c	scsi: core: bsg: Remove usage of the deprecated ida_simple_xxx() API	2022-06-21 21:22:51 -04:00
disk-events.c	block: remove genhd.h	2022-02-02 07:49:59 -07:00
elevator.c	block: fix up elevator_type refcounting	2022-10-23 18:59:17 -06:00
elevator.h	block: add proper helpers for elevator_type module refcount management	2022-10-23 18:59:17 -06:00
fops.c	new iov_iter flavour - ITER_UBUF	2022-08-08 22:37:15 -04:00
genhd.c	Merge branch 'for-6.1/block' into block-6.1	2022-10-10 11:26:40 -06:00
holder.c	block: remove WARN_ON() from bd_link_disk_holder	2022-06-23 07:48:05 -06:00
ioctl.c	block: replace blkdev_nr_zones with bdev_nr_zones	2022-07-06 06:46:26 -06:00
ioprio.c	block: Fix handling of tasks without ioprio in ioprio_get(2)	2022-06-27 06:29:12 -06:00
Kconfig	block: remove "select BLK_RQ_IO_DATA_LEN" from BLK_CGROUP_IOCOST dependency	2022-06-29 08:35:57 -06:00
Kconfig.iosched	block: only build the icq tracking code when needed	2021-12-16 10:59:02 -07:00
kyber-iosched.c	block/kyber: Use the new blk_opf_t type	2022-07-14 12:14:30 -06:00
Makefile	blk-cgroup: move blkcg_{get,set}_fc_appid out of line	2022-05-02 14:06:20 -06:00
mq-deadline.c	block/mq-deadline: Use the new blk_opf_t type	2022-07-14 12:14:30 -06:00
opal_proto.h	block: sed-opal: Add ioctl to return device status	2022-08-22 07:52:51 -06:00
sed-opal.c	block: sed-opal: Add ioctl to return device status	2022-08-22 07:52:51 -06:00
t10-pi.c	block: add pi for extended integrity	2022-03-07 12:48:35 -07:00