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Ming Lei
aa7cb24019
[ Upstream commit3dbaacf6ab] 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:1059699f87("block: move blkcg initialization/destroy into disk allocation/release handler") Cc: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260311032837.2368714-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>