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 <jthumshirn@suse.de>
[hch: increased lock hold time a bit to be safe, added a comment
 and updated the changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Johannes Thumshirn 2018-06-01 09:11:20 +02:00 committed by Jens Axboe
parent f39ae4719b
commit 12a0b66221
2 changed files with 5 additions and 1 deletions

View file

@ -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:

View file

@ -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;