linux/block, branch v6.4

block: make sure local irq is disabled when calling __blkcg_rstat_flush

2023-06-22T13:44:00Z

When __blkcg_rstat_flush() is called from cgroup_rstat_flush*() code path, interrupt is always disabled. When we start to flush blkcg per-cpu stats list in __blkg_release() for avoiding to leak blkcg_gq's reference in commit 20cb1c2fb756 ("blk-cgroup: Flush stats before releasing blkcg_gq"), local irq isn't disabled yet, then lockdep warning may be triggered because the dependent cgroup locks may be acquired from irq(soft irq) handler. Fix the issue by disabling local irq always. Fixes: 20cb1c2fb756 ("blk-cgroup: Flush stats before releasing blkcg_gq") Reported-by: Shinichiro Kawasaki Closes: https://lore.kernel.org/linux-block/pz2wzwnmn5tk3pwpskmjhli6g3qly7eoknilb26of376c7kwxy@qydzpvt6zpis/T/#u Cc: stable@vger.kernel.org Cc: Jay Shin Cc: Tejun Heo Cc: Waiman Long Signed-off-by: Ming Lei Reviewed-by: Waiman Long Link: https://lore.kernel.org/r/20230622084249.1208005-1-ming.lei@redhat.com Signed-off-by: Jens Axboe

blk-cgroup: Flush stats before releasing blkcg_gq

2023-06-12T01:49:29Z

As noted by Michal, the blkg_iostat_set's in the lockless list hold reference to blkg's to protect against their removal. Those blkg's hold reference to blkcg. When a cgroup is being destroyed, cgroup_rstat_flush() is only called at css_release_work_fn() which is called when the blkcg reference count reaches 0. This circular dependency will prevent blkcg and some blkgs from being freed after they are made offline. It is less a problem if the cgroup to be destroyed also has other controllers like memory that will call cgroup_rstat_flush() which will clean up the reference count. If block is the only controller that uses rstat, these offline blkcg and blkgs may never be freed leaking more and more memory over time. To prevent this potential memory leak: - flush blkcg per-cpu stats list in __blkg_release(), when no new stat can be added - add global blkg_stat_lock for covering concurrent parent blkg stat update - don't grab bio->bi_blkg reference when adding the stats into blkcg's per-cpu stat list since all stats are guaranteed to be consumed before releasing blkg instance, and grabbing blkg reference for stats was the most fragile part of original patch Based on Waiman's patch: https://lore.kernel.org/linux-block/20221215033132.230023-3-longman@redhat.com/ Fixes: 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") Cc: stable@vger.kernel.org Reported-by: Jay Shin Acked-by: Tejun Heo Cc: Waiman Long Cc: mkoutny@suse.com Cc: Yosry Ahmed Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20230609234249.1412858-1-ming.lei@redhat.com Signed-off-by: Jens Axboe

blk-mq: fix blk_mq_hw_ctx active request accounting

2023-06-03T23:20:00Z

The nr_active counter continues to increase over time which causes the blk_mq_get_tag to hang until the thread is rescheduled to a different core despite there are still tags available. kernel-stack INFO: task inboundIOReacto:3014879 blocked for more than 2 seconds Not tainted 6.1.15-amd64 #1 Debian 6.1.15~debian11 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:inboundIOReacto state:D stack:0 pid:3014879 ppid:4557 flags:0x00000000 Call Trace: __schedule+0x351/0xa20 scheduler+0x5d/0xe0 io_schedule+0x42/0x70 blk_mq_get_tag+0x11a/0x2a0 ? dequeue_task_stop+0x70/0x70 __blk_mq_alloc_requests+0x191/0x2e0 kprobe output showing RQF_MQ_INFLIGHT bit is not cleared before __blk_mq_free_request being called. 320 320 kworker/29:1H __blk_mq_free_request rq_flags 0x220c0 in-flight 1 b'__blk_mq_free_request+0x1 [kernel]' b'bt_iter+0x50 [kernel]' b'blk_mq_queue_tag_busy_iter+0x318 [kernel]' b'blk_mq_timeout_work+0x7c [kernel]' b'process_one_work+0x1c4 [kernel]' b'worker_thread+0x4d [kernel]' b'kthread+0xe6 [kernel]' b'ret_from_fork+0x1f [kernel]' Signed-off-by: Tian Lan Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter") Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20230513221227.497327-1-tilan7663@gmail.com Signed-off-by: Jens Axboe

block: fix revalidate performance regression

2023-05-29T14:40:32Z

The scsi driver function sd_read_block_characteristics() always calls disk_set_zoned() to a disk zoned model correctly, in case the device model changed. This is done even for regular disks to set the zoned model to BLK_ZONED_NONE and free any zone related resources if the drive previously was zoned. This behavior significantly impact the time it takes to revalidate disks on a large system as the call to disk_clear_zone_settings() done from disk_set_zoned() for the BLK_ZONED_NONE case results in the device request queued to be frozen, even if there are no zone resources to free. Avoid this overhead for non-zoned devices by not calling disk_clear_zone_settings() in disk_set_zoned() if the device model was already set to BLK_ZONED_NONE, which is always the case for regular devices. Reported by: Brian Bunker Fixes: 508aebb80527 ("block: introduce blk_queue_clear_zone_settings()") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20230529073237.1339862-1-dlemoal@kernel.org Signed-off-by: Jens Axboe

block: make bio_check_eod work for zero sized devices

2023-05-24T14:19:26Z

Since the dawn of time bio_check_eod has a check for a non-zero size of the device. This doesn't really make any sense as we never want to send I/O to a device that's been set to zero size, or never moved out of that. I am a bit surprised we haven't caught this for a long time, but the removal of the extra validation inside of zram caused syzbot to trip over this issue recently. I've added a Fixes tag for that commit, but the issue really goes back way before git history. Fixes: 9fe95babc742 ("zram: remove valid_io_request") Reported-by: syzbot+b8d61a58b7c7ebd2c8e0@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230524060538.1593686-1-hch@lst.de Signed-off-by: Jens Axboe

block: fix bio-cache for passthru IO

2023-05-23T17:11:29Z

commit <8af870aa5b847> ("block: enable bio caching use for passthru IO") introduced bio-cache for passthru IO. In case when nr_vecs are greater than BIO_INLINE_VECS, bio and bvecs are allocated from mempool (instead of percpu cache) and REQ_ALLOC_CACHE is cleared. This causes the side effect of not freeing bio/bvecs into mempool on completion. This patch lets the passthru IO fallback to allocation using bio_kmalloc when nr_vecs are greater than BIO_INLINE_VECS. The corresponding bio is freed during call to blk_mq_map_bio_put during completion. Cc: stable@vger.kernel.org # 6.1 fixes <8af870aa5b847> ("block: enable bio caching use for passthru IO") Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20230523111709.145676-1-anuj20.g@samsung.com Signed-off-by: Jens Axboe

blk-mq: fix race condition in active queue accounting

2023-05-23T17:10:16Z

If multiple CPUs are sharing the same hardware queue, it can cause leak in the active queue counter tracking when __blk_mq_tag_busy() is executed simultaneously. Fixes: ee78ec1077d3 ("blk-mq: blk_mq_tag_busy is no need to return a value") Signed-off-by: Tian Lan Reviewed-by: Ming Lei Reviewed-by: Damien Le Moal Reviewed-by: John Garry Link: https://lore.kernel.org/r/20230522210555.794134-1-tilan7663@gmail.com Signed-off-by: Jens Axboe

blk-wbt: fix that wbt can't be disabled by default

2023-05-23T17:08:53Z

commit b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()") removes the checking of CONFIG_BLK_WBT_MQ by mistake, which is used to control enable or disable wbt by default. Fix the problem by adding back the checking. This patch also do a litter cleanup to make related code more readable. Fixes: b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()") Reported-by: Lukas Bulwahn Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@mail.gmail.com/t/ Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230522121854.2928880-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe

block: Deny writable memory mapping if block is read-only

2023-05-20T02:17:10Z

User should not be able to write block device if it is read-only at block level (e.g force_ro attribute). This is ensured in the regular fops write operation (blkdev_write_iter) but not when writing via user mapping (mmap), allowing user to actually write a read-only block device via a PROT_WRITE mapping. Example: This can lead to integrity issue of eMMC boot partition (e.g mmcblk0boot0) which is read-only by default. To fix this issue, simply deny shared writable mapping if the block is readonly. Note: Block remains writable if switch to read-only is performed after the initial mapping, but this is expected behavior according to commit a32e236eb93e ("Partially revert "block: fail op_is_write() requests to read-only partitions"")'. Signed-off-by: Loic Poulain Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230510074223.991297-1-loic.poulain@linaro.org Signed-off-by: Jens Axboe

Merge tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux

2023-05-06T15:28:58Z

Pull more block updates from Jens Axboe: - MD pull request via Song: - Improve raid5 sequential IO performance on spinning disks, which fixes a regression since v6.0 (Jan Kara) - Fix bitmap offset types, which fixes an issue introduced in this merge window (Jonathan Derrick) - Cleanup of hweight type used for cgroup writeback (Maxim) - Fix a regression with the "has_submit_bio" changes across partitions (Ming) - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing. We used to set this flag on queues non blk-mq queues, and hence some drivers clear it unconditionally. Since all of these have since been converted to true blk-mq drivers, drop the useless clear as the bit is not set (Chaitanya) - Fix the flags being set in a bio for a flush for drbd (Christoph) - Cleanup and deduplication of the code handling setting block device capacity (Damien) - Fix for ublk handling IO timeouts (Ming) - Fix for a regression in blk-cgroup teardown (Tao) - NBD documentation and code fixes (Eric) - Convert blk-integrity to using device_attributes rather than a second kobject to manage lifetimes (Thomas) * tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux: ublk: add timeout handler drbd: correctly submit flush bio on barrier mailmap: add mailmap entries for Jens Axboe block: Skip destroyed blkg when restart in blkg_destroy_all() writeback: fix call of incorrect macro md: Fix bitmap offset type in sb writer md/raid5: Improve performance for sequential IO docs nbd: userspace NBD now favors github over sourceforge block nbd: use req.cookie instead of req.handle uapi nbd: add cookie alias to handle uapi nbd: improve doc links to userspace spec blk-integrity: register sysfs attributes on struct device blk-integrity: convert to struct device_attribute blk-integrity: use sysfs_emit block/drivers: remove dead clear of random flag block: sync part's ->bd_has_submit_bio with disk's block: Cleanup set_capacity()/bdev_set_nr_sectors()