From 433ef6dea38de57289ce6ae26147cabe03c9b114 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Sat, 29 May 2021 13:54:22 +0200 Subject: [PATCH] nvme-multipath: call del_gendisk() in nvme_mpath_check_last_path() We cannot call del_gendisk() during the final nvme_put_ns_head(), as this might be called from blkdev_put(), as we then will deadlock on bd_mutex: [ 1108.529767] __mutex_lock.constprop.0+0x2a4/0x470 [ 1108.534472] ? __kernfs_remove.part.0+0x174/0x1f0 [ 1108.539178] ? kernfs_remove_by_name_ns+0x5c/0x90 [ 1108.543885] del_gendisk+0x99/0x230 [ 1108.547378] nvme_mpath_remove_disk+0x97/0xb0 [nvme_core] [ 1108.552787] nvme_put_ns_head+0x2a/0xb0 [nvme_core] [ 1108.557664] __blkdev_put+0x115/0x160 [ 1108.561339] blkdev_put+0x4c/0x130 [ 1108.564745] blkdev_close+0x22/0x30 [ 1108.568238] __fput+0x94/0x240 So call 'del_gendisk()' when checking if the last path has been removed to avoid this deadlock. Signed-off-by: Hannes Reinecke --- drivers/nvme/host/multipath.c | 13 +++++++++++-- drivers/nvme/host/nvme.h | 9 +-------- 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 127a17b4c13d..22e2febf86bc 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -776,14 +776,23 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id) #endif } -void nvme_mpath_remove_disk(struct nvme_ns_head *head) +void nvme_mpath_check_last_path(struct nvme_ns *ns) { + struct nvme_ns_head *head = ns->head; + if (!head->disk) return; - if (head->disk->flags & GENHD_FL_UP) { + + if (list_empty(&head->list) && head->disk->flags & GENHD_FL_UP) { nvme_cdev_del(&head->cdev, &head->cdev_device); del_gendisk(head->disk); } +} + +void nvme_mpath_remove_disk(struct nvme_ns_head *head) +{ + if (!head->disk) + return; blk_set_queue_dying(head->disk->queue); /* make sure all pending bios are cleaned up */ kblockd_schedule_work(&head->requeue_work); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 1f397ecba16c..8a497a420ea2 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -716,14 +716,7 @@ void nvme_mpath_uninit(struct nvme_ctrl *ctrl); void nvme_mpath_stop(struct nvme_ctrl *ctrl); bool nvme_mpath_clear_current_path(struct nvme_ns *ns); void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl); - -static inline void nvme_mpath_check_last_path(struct nvme_ns *ns) -{ - struct nvme_ns_head *head = ns->head; - - if (head->disk && list_empty(&head->list)) - kblockd_schedule_work(&head->requeue_work); -} +void nvme_mpath_check_last_path(struct nvme_ns *ns); static inline void nvme_trace_bio_complete(struct request *req) { -- 2.26.2