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327c428ba7
bio_set_dev() associates the bio with a blkg through bio_associate_blkg(). If the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with spin_lock_irq() and releases it with spin_unlock_irq(), which unconditionally enables local interrupts. Callers may call bio_set_dev() with interrupts already disabled, e.g. dm-thin's pool_map() does so while holding pool->lock taken with spin_lock_irq(). The nested spin_unlock_irq() then enables interrupts while pool->lock is still held, so an I/O completion softirq can run on the same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio() -> complete_mapping_preparation()) and deadlock. lockdep reports this as inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage. Commit3a762de55b("block: save irq state in blkg_lookup_create()") fixed the same problem while the lock lived in blkg_lookup_create(), but commit9327a865e3("blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()") moved the locking into blkg_tryget_closest() and reverted it to spin_lock_irq(). Save and restore the caller's IRQ state instead. Fixes:9327a865e3("blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()") Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Hao Zhang <zhanghao1@kylinos.cn> Acked-by: Tejun Heo <tj@kernel.org> Link: https://patch.msgid.link/aqQmqb1k57PXj8Ef@192.168.1.215 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2263 lines
59 KiB
2263 lines
59 KiB