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authorJohannes Thumshirn <jthumshirn@suse.de>2018-06-01 10:11:20 +0300
committerJens Axboe <axboe@kernel.dk>2018-06-08 21:51:10 +0300
commit12a0b662210702c6b0ce9f66f0c177ff1dea99cb (patch)
tree1ec47a51a7aa9cfdd5acc59f1970b2523fb76ae4
parentf39ae4719b1c33d048aa4d3c284d82ecf252742b (diff)
downloadlinux-12a0b662210702c6b0ce9f66f0c177ff1dea99cb.tar.xz
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>
-rw-r--r--drivers/nvme/host/fabrics.c3
-rw-r--r--drivers/nvme/host/fabrics.h3
2 files changed, 5 insertions, 1 deletions
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;