From 12a0b662210702c6b0ce9f66f0c177ff1dea99cb Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Fri, 1 Jun 2018 09:11:20 +0200 Subject: [PATCH] nvme: don't hold nvmf_transports_rwsem for more than transport lookups Only take nvmf_transports_rwsem when doing a lookup of registered transports, so that a blocking ->create_ctrl doesn't prevent other actions on /dev/nvme-fabrics. Signed-off-by: Johannes Thumshirn [hch: increased lock hold time a bit to be safe, added a comment and updated the changelog] Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/nvme/host/fabrics.c | 3 ++- drivers/nvme/host/fabrics.h | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c index 5f5f7067c41d..fa32c1216409 100644 --- a/drivers/nvme/host/fabrics.c +++ b/drivers/nvme/host/fabrics.c @@ -952,6 +952,7 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count) ret = -EBUSY; goto out_unlock; } + up_read(&nvmf_transports_rwsem); ret = nvmf_check_required_opts(opts, ops->required_opts); if (ret) @@ -968,11 +969,11 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count) } module_put(ops->module); - up_read(&nvmf_transports_rwsem); return ctrl; out_module_put: module_put(ops->module); + goto out_free_opts; out_unlock: up_read(&nvmf_transports_rwsem); out_free_opts: diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h index 0cf0460a5c92..7491a0bbf711 100644 --- a/drivers/nvme/host/fabrics.h +++ b/drivers/nvme/host/fabrics.h @@ -124,6 +124,9 @@ struct nvmf_ctrl_options { * 1. At minimum, 'required_opts' and 'allowed_opts' should * be set to the same enum parsing options defined earlier. * 2. create_ctrl() must be defined (even if it does nothing) + * 3. struct nvmf_transport_ops must be statically allocated in the + * modules .bss section so that a pure module_get on @module + * prevents the memory from beeing freed. */ struct nvmf_transport_ops { struct list_head entry;