diff options
| author | Chunguang Xu <chunguang.xu@shopee.com> | 2024-03-11 10:09:27 +0800 |
|---|---|---|
| committer | Keith Busch <kbusch@kernel.org> | 2024-03-14 11:32:39 -0700 |
| commit | de105068fead55ed5c07ade75e9c8e7f86a00d1d (patch) | |
| tree | 1762f5e1530e9b93e5a724eb3883f20228392a91 /drivers/nvme | |
| parent | 2bc91743096756d7c97d10c7079617192211369b (diff) | |
| download | linux-de105068fead55ed5c07ade75e9c8e7f86a00d1d.tar.gz | |
nvme: fix reconnection fail due to reserved tag allocation
We found a issue on production environment while using NVMe over RDMA,
admin_q reconnect failed forever while remote target and network is ok.
After dig into it, we found it may caused by a ABBA deadlock due to tag
allocation. In my case, the tag was hold by a keep alive request
waiting inside admin_q, as we quiesced admin_q while reset ctrl, so the
request maked as idle and will not process before reset success. As
fabric_q shares tagset with admin_q, while reconnect remote target, we
need a tag for connect command, but the only one reserved tag was held
by keep alive command which waiting inside admin_q. As a result, we
failed to reconnect admin_q forever. In order to fix this issue, I
think we should keep two reserved tags for admin queue.
Fixes: ed01fee283a0 ("nvme-fabrics: only reserve a single tag")
Signed-off-by: Chunguang Xu <chunguang.xu@shopee.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Diffstat (limited to 'drivers/nvme')
| -rw-r--r-- | drivers/nvme/host/core.c | 6 | ||||
| -rw-r--r-- | drivers/nvme/host/fabrics.h | 7 |
2 files changed, 4 insertions, 9 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0dcaf3973dc49..fb55b6ac03856 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4385,7 +4385,8 @@ int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set, set->ops = ops; set->queue_depth = NVME_AQ_MQ_TAG_DEPTH; if (ctrl->ops->flags & NVME_F_FABRICS) - set->reserved_tags = NVMF_RESERVED_TAGS; + /* Reserved for fabric connect and keep alive */ + set->reserved_tags = 2; set->numa_node = ctrl->numa_node; set->flags = BLK_MQ_F_NO_SCHED; if (ctrl->ops->flags & NVME_F_BLOCKING) @@ -4454,7 +4455,8 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set, if (ctrl->quirks & NVME_QUIRK_SHARED_TAGS) set->reserved_tags = NVME_AQ_DEPTH; else if (ctrl->ops->flags & NVME_F_FABRICS) - set->reserved_tags = NVMF_RESERVED_TAGS; + /* Reserved for fabric connect */ + set->reserved_tags = 1; set->numa_node = ctrl->numa_node; set->flags = BLK_MQ_F_SHOULD_MERGE; if (ctrl->ops->flags & NVME_F_BLOCKING) diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h index 06cc54851b1be..37c974c38dcb0 100644 --- a/drivers/nvme/host/fabrics.h +++ b/drivers/nvme/host/fabrics.h @@ -19,13 +19,6 @@ #define NVMF_DEF_FAIL_FAST_TMO -1 /* - * Reserved one command for internal usage. This command is used for sending - * the connect command, as well as for the keep alive command on the admin - * queue once live. - */ -#define NVMF_RESERVED_TAGS 1 - -/* * Define a host as seen by the target. We allocate one at boot, but also * allow the override it when creating controllers. This is both to provide * persistence of the Host NQN over multiple boots, and to allow using |