kernel/linux.git/block, branch v6.1.175

blk-cgroup: wait for blkcg cleanup before initializing new disk

2026-06-01T15:39:04+00:00

[ Upstream commit 3dbaacf6ab68f81e3375fe769a2ecdbd3ce386fd ] When a queue is shared across disk rebind (e.g., SCSI unbind/bind), the previous disk's blkcg state is cleaned up asynchronously via disk_release() -> blkcg_exit_disk(). If the new disk's blkcg_init_disk() runs before that cleanup finishes, we may overwrite q->root_blkg while the old one is still alive, and radix_tree_insert() in blkg_create() fails with -EEXIST because the old blkg entries still occupy the same queue id slot in blkcg->blkg_tree. This causes the sd probe to fail with -ENOMEM. Fix it by waiting in blkcg_init_disk() for root_blkg to become NULL, which indicates the previous disk's blkcg cleanup has completed. Fixes: 1059699f87eb ("block: move blkcg initialization/destroy into disk allocation/release handler") Cc: Yi Zhang Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260311032837.2368714-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none

2026-06-01T15:38:44+00:00

[ Upstream commit 245165658e1c9f95c0fecfe02b9b1ebd30a1198a ] After grabbing q->sysfs_lock, q->elevator may become NULL because of elevator switch. Fix the NULL dereference on q->elevator by checking it with lock. Reported-by: Guangwu Zhang Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20230616132354.415109-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Leon Chen Signed-off-by: Sasha Levin

block: Fix the blk_mq_destroy_queue() documentation

2026-04-11T12:16:38+00:00

commit 81ea42b9c3d61ea34d82d900ed93f4b4851f13b0 upstream. Commit 2b3f056f72e5 moved a blk_put_queue() call from blk_mq_destroy_queue() into its callers. Reflect this change in the documentation block above blk_mq_destroy_queue(). Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Chaitanya Kulkarni Cc: Keith Busch Fixes: 2b3f056f72e5 ("blk-mq: move the call to blk_put_queue out of blk_mq_destroy_queue") Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230130211233.831613-1-bvanassche@acm.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: fix resource leak in blk_register_queue() error path

2026-04-11T12:16:34+00:00

[ Upstream commit 40f2eb9b531475dd01b683fdaf61ca3cfd03a51e ] When registering a queue fails after blk_mq_sysfs_register() is successful but the function later encounters an error, we need to clean up the blk_mq_sysfs resources. Add the missing blk_mq_sysfs_unregister() call in the error path to properly clean up these resources and prevent a memory leak. Fixes: 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism") Signed-off-by: Zheng Qixing Reviewed-by: Christoph Hellwig Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20250412092554.475218-1-zhengqixing@huaweicloud.com Signed-off-by: Jens Axboe [ Minor context change fixed. ] Signed-off-by: Robert Garcia Signed-off-by: Greg Kroah-Hartman

blk-mq: move the call to blk_put_queue out of blk_mq_destroy_queue

2026-04-11T12:16:33+00:00

[ Upstream commit 2b3f056f72e56fa07df69b4705e0b46a6c08e77c ] The fact that blk_mq_destroy_queue also drops a queue reference leads to various places having to grab an extra reference. Move the call to blk_put_queue into the callers to allow removing the extra references. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Chaitanya Kulkarni Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20221018135720.670094-2-hch@lst.de [axboe: fix fabrics_q vs admin_q conflict in nvme core.c] Signed-off-by: Jens Axboe Stable-dep-of: 03b3bcd319b3 ("nvme: fix admin request_queue lifetime") Signed-off-by: Maximilian Heyne Tested-by: Fedor Pchelkin Signed-off-by: Sasha Levin

blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()

2026-03-04T12:20:15+00:00

[ Upstream commit 9d20fd6ce1ba9733cd5ac96fcab32faa9fc404dd ] In blk_mq_update_nr_hw_queues(), debugfs_mutex is not held while creating debugfs entries for hctxs. Hence add debugfs_mutex there, it's safe because queue is not frozen. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block,bfq: fix aux stat accumulation destination

2026-02-11T12:37:21+00:00

[ Upstream commit 04bdb1a04d8a2a89df504c1e34250cd3c6e31a1c ] Route bfqg_stats_add_aux() time accumulation into the destination stats object instead of the source, aligning with other stat fields. Reviewed-by: Yu Kuai Signed-off-by: shechenglong Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()

2026-02-06T15:44:23+00:00

[ Upstream commit 3d2af77e31ade05ff7ccc3658c3635ec1bea0979 ] When blkg_alloc() is called to allocate a blkcg_gq structure with the associated blkg_iostat_set's, there are 2 fields within blkg_iostat_set that requires proper initialization - blkg & sync. The former field was introduced by commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") while the later one was introduced by commit f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat"). Unfortunately those fields in the blkg_iostat_set's are not properly re-initialized when they are cleared in v1's blkcg_reset_stats(). This can lead to a kernel panic due to NULL pointer access of the blkg pointer. The missing initialization of sync is less problematic and can be a problem in a debug kernel due to missing lockdep initialization. Fix these problems by re-initializing them after memory clearing. Fixes: 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") Fixes: f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat") Signed-off-by: Waiman Long Reviewed-by: Ming Lei Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20230606180724.2455066-1-longman@redhat.com Signed-off-by: Jens Axboe [ Remove this line: bis -> blkg = blkg for blkg was introduced by commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") since v6.2. ] Signed-off-by: Alva Lan Signed-off-by: Greg Kroah-Hartman

blk-mq: setup queue ->tag_set before initializing hctx

2026-01-11T14:19:26+00:00

commit c25c0c9035bb8b28c844dfddeda7b8bdbcfcae95 upstream. Commit 7b815817aa58 ("blk-mq: add helper for checking if one CPU is mapped to specified hctx") needs to check queue mapping via tag set in hctx's cpuhp handler. However, q->tag_set may not be setup yet when the cpuhp handler is enabled, then kernel oops is triggered. Fix the issue by setup queue tag_set before initializing hctx. Cc: stable@vger.kernel.org Reported-and-tested-by: Rick Koch Closes: https://lore.kernel.org/linux-block/CANa58eeNDozLaBHKPLxSAhEy__FPfJT_F71W=sEQw49UCrC9PQ@mail.gmail.com Fixes: 7b815817aa58 ("blk-mq: add helper for checking if one CPU is mapped to specified hctx") Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Reviewed-by: John Garry Link: https://lore.kernel.org/r/20241014005115.2699642-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blk-mq: add helper for checking if one CPU is mapped to specified hctx

2026-01-11T14:19:13+00:00

commit 7b815817aa58d2e2101feb2fcf64c60cae0b2695 upstream. Commit a46c27026da1 ("blk-mq: don't schedule block kworker on isolated CPUs") rules out isolated CPUs from hctx->cpumask, and hctx->cpumask should only be used for scheduling kworker. Add helper blk_mq_cpu_mapped_to_hctx() and apply it into cpuhp handlers. This patch avoids to forget clearing INACTIVE of hctx state in case that one isolated CPU becomes online, and fixes hang issue when allocating request from this hctx's tags. Cc: Raju Cheerla Fixes: a46c27026da1 ("blk-mq: don't schedule block kworker on isolated CPUs") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20240517020514.149771-1-ming.lei@redhat.com Tested-by: Raju Cheerla Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman