diff options
| author | Keith Busch <kbusch@kernel.org> | 2024-05-21 06:41:45 -0700 |
|---|---|---|
| committer | Keith Busch <kbusch@kernel.org> | 2024-05-28 09:43:32 -0700 |
| commit | be647e2c76b27f409cdd520f66c95be888b553a3 (patch) | |
| tree | 281e6dc4405db42ef18daa67af41df49cf8f8683 /drivers/nvme/host/nvme.h | |
| parent | 1bd293fcf3af84674e82ed022c049491f3768840 (diff) | |
nvme: use srcu for iterating namespace list
The nvme pci driver synchronizes with all the namespace queues during a
reset to ensure that there's no pending timeout work.
Meanwhile the timeout work potentially iterates those same namespaces to
freeze their queues.
Each of those namespace iterations use the same read lock. If a write
lock should somehow get between the synchronize and freeze steps, then
forward progress is deadlocked.
We had been relying on the nvme controller state machine to ensure the
reset work wouldn't conflict with timeout work. That guarantee may be a
bit fragile to rely on, so iterate the namespace lists without taking
potentially circular locks, as reported by lockdep.
Link: https://lore.kernel.org/all/20220930001943.zdbvolc3gkekfmcv@shindev/
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Diffstat (limited to 'drivers/nvme/host/nvme.h')
| -rw-r--r-- | drivers/nvme/host/nvme.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index c43a30753d87..f3a41133ac3f 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -282,7 +282,8 @@ struct nvme_ctrl { struct blk_mq_tag_set *tagset; struct blk_mq_tag_set *admin_tagset; struct list_head namespaces; - struct rw_semaphore namespaces_rwsem; + struct mutex namespaces_lock; + struct srcu_struct srcu; struct device ctrl_device; struct device *device; /* char device */ #ifdef CONFIG_NVME_HWMON @@ -1160,6 +1161,7 @@ void nvme_passthru_end(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u32 effects, struct nvme_command *cmd, int status); struct nvme_ctrl *nvme_ctrl_from_file(struct file *file); struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid); +bool nvme_get_ns(struct nvme_ns *ns); void nvme_put_ns(struct nvme_ns *ns); static inline bool nvme_multi_css(struct nvme_ctrl *ctrl) |