linux-stable/block
Colin Ian King 1655cfc852 block, bfq: Fix division by zero error on zero wsum
[ Upstream commit e53413f8de ]

When the weighted sum is zero the calculation of limit causes
a division by zero error. Fix this by continuing to the next level.

This was discovered by running as root:

stress-ng --ioprio 0

Fixes divison by error oops:

[  521.450556] divide error: 0000 [#1] SMP NOPTI
[  521.450766] CPU: 2 PID: 2684464 Comm: stress-ng-iopri Not tainted 6.2.1-1280.native #1
[  521.451117] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
[  521.451627] RIP: 0010:bfqq_request_over_limit+0x207/0x400
[  521.451875] Code: 01 48 8d 0c c8 74 0b 48 8b 82 98 00 00 00 48 8d 0c c8 8b 85 34 ff ff ff 48 89 ca 41 0f af 41 50 48 d1 ea 48 98 48 01 d0 31 d2 <48> f7 f1 41 39 41 48 89 85 34 ff ff ff 0f 8c 7b 01 00 00 49 8b 44
[  521.452699] RSP: 0018:ffffb1af84eb3948 EFLAGS: 00010046
[  521.452938] RAX: 000000000000003c RBX: 0000000000000000 RCX: 0000000000000000
[  521.453262] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffb1af84eb3978
[  521.453584] RBP: ffffb1af84eb3a30 R08: 0000000000000001 R09: ffff8f88ab8a4ba0
[  521.453905] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8f88ab8a4b18
[  521.454224] R13: ffff8f8699093000 R14: 0000000000000001 R15: ffffb1af84eb3970
[  521.454549] FS:  00005640b6b0b580(0000) GS:ffff8f88b3880000(0000) knlGS:0000000000000000
[  521.454912] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  521.455170] CR2: 00007ffcbcae4e38 CR3: 00000002e46de001 CR4: 0000000000770ee0
[  521.455491] PKRU: 55555554
[  521.455619] Call Trace:
[  521.455736]  <TASK>
[  521.455837]  ? bfq_request_merge+0x3a/0xc0
[  521.456027]  ? elv_merge+0x115/0x140
[  521.456191]  bfq_limit_depth+0xc8/0x240
[  521.456366]  __blk_mq_alloc_requests+0x21a/0x2c0
[  521.456577]  blk_mq_submit_bio+0x23c/0x6c0
[  521.456766]  __submit_bio+0xb8/0x140
[  521.457236]  submit_bio_noacct_nocheck+0x212/0x300
[  521.457748]  submit_bio_noacct+0x1a6/0x580
[  521.458220]  submit_bio+0x43/0x80
[  521.458660]  ext4_io_submit+0x23/0x80
[  521.459116]  ext4_do_writepages+0x40a/0xd00
[  521.459596]  ext4_writepages+0x65/0x100
[  521.460050]  do_writepages+0xb7/0x1c0
[  521.460492]  __filemap_fdatawrite_range+0xa6/0x100
[  521.460979]  file_write_and_wait_range+0xbf/0x140
[  521.461452]  ext4_sync_file+0x105/0x340
[  521.461882]  __x64_sys_fsync+0x67/0x100
[  521.462305]  ? syscall_exit_to_user_mode+0x2c/0x1c0
[  521.462768]  do_syscall_64+0x3b/0xc0
[  521.463165]  entry_SYSCALL_64_after_hwframe+0x5a/0xc4
[  521.463621] RIP: 0033:0x5640b6c56590
[  521.464006] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 80 3d 71 70 0e 00 00 74 17 b8 4a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20230413133009.1605335-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-24 17:32:38 +01:00
..
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: fix uaf for bfqq in bic_set_bfqq() 2023-02-09 11:28:06 +01:00
bfq-iosched.c block, bfq: Fix division by zero error on zero wsum 2023-05-24 17:32:38 +01:00
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: bio-integrity: Copy flags when bio_integrity_payload is cloned 2023-03-10 09:32:46 +01:00
bio.c block: clear bio->bi_bdev when putting a bio back in the cache 2023-03-10 09:34:02 +01:00
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 block: Skip destroyed blkg when restart in blkg_destroy_all() 2023-05-17 11:53:33 +02:00
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 block: be a bit more careful in checking for NULL bdev while polling 2023-03-10 09:34:02 +01:00
blk-crypto-fallback.c treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
blk-crypto-internal.h blk-mq: release crypto keyslot before reporting I/O complete 2023-05-11 23:03:00 +09:00
blk-crypto-profile.c blk-crypto: make blk_crypto_evict_key() more robust 2023-05-11 23:03:01 +09:00
blk-crypto-sysfs.c blk-crypto: show crypto capabilities in sysfs 2022-02-28 06:40:23 -07:00
blk-crypto.c blk-crypto: make blk_crypto_evict_key() more robust 2023-05-11 23:03:01 +09:00
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 block/blk-iocost (gcc13): keep large values in a new enum 2023-05-11 23:03:42 +09:00
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 blk-mq: release crypto keyslot before reporting I/O complete 2023-05-11 23:03:00 +09:00
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 blk-mq: correct stale comment of .get_budget 2023-03-10 09:32:44 +01:00
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: fix possible memleak when register 'hctx' failed 2022-12-31 13:33:03 +01:00
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 blk-mq: don't plug for head insertions in blk_execute_rq_nowait 2023-05-11 23:03:22 +09:00
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: make blk_set_default_limits() private 2022-11-16 15:58:11 -07:00
blk-stat.c blk-stat: fix QUEUE_FLAG_STATS clear 2023-05-11 23:03:00 +09:00
blk-stat.h block: make queue stat accounting a reference 2021-12-14 17:23:05 -07:00
blk-sysfs.c blk-throttle: pass a gendisk to blk_throtl_register_queue 2022-09-26 19:17:27 -06:00
blk-throttle.c blk-throttle: Fix that bps of child could exceed bps limited in parent 2023-04-13 16:55:37 +02:00
blk-throttle.h blk-throttle: pass a gendisk to blk_throtl_cancel_bios 2022-09-26 19:17:28 -06:00
blk-timeout.c
blk-wbt.c blk-wbt: fix that 'rwb->wc' is always set to 1 in wbt_init() 2022-10-09 07:48:16 -06:00
blk-wbt.h blk-wbt: remove wbt_track stub 2022-03-31 12:58:38 -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 block: Revert "block: Do not reread partition table on exclusively open device" 2023-03-17 08:50:20 +01:00
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 blk-mq: use quiesced elevator switch when reinitializing queues 2022-09-27 09:58:56 -06:00
elevator.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
fops.c block: don't allow multiple bios for IOCB_NOWAIT issue 2023-03-10 09:34:02 +01:00
genhd.c block: don't set GD_NEED_PART_SCAN if scan partition failed 2023-04-13 16:55:32 +02:00
holder.c block: remove WARN_ON() from bd_link_disk_holder 2022-06-23 07:48:05 -06:00
ioctl.c block: fix scan partition for exclusively open device again 2023-03-17 08:50:21 +01:00
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: Rename deadline_is_seq_writes() 2023-01-24 07:24:44 +01:00
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: kmalloc the cmd/resp buffers 2022-11-08 07:14:35 -07:00
t10-pi.c block: add pi for extended integrity 2022-03-07 12:48:35 -07:00