nvmet: track and limit the number of namespaces per subsystem

TP 4004 introduces a new 'Maximum Number of Allocated Namespaces' field
in the Identify controller data to help the host size resources.  Put
an upper limit on the supported namespaces to be able to support this
value as supporting 32-bits worth of namespaces would lead to very
large buffers.  The limit is completely arbitrary at this point.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
This commit is contained in:
Christoph Hellwig 2018-05-13 19:00:13 +02:00
parent 4ee4328048
commit 793c7cfce0
3 changed files with 16 additions and 1 deletions

View file

@ -252,6 +252,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
id->nn = cpu_to_le32(ctrl->subsys->max_nsid);
id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
NVME_CTRL_ONCS_WRITE_ZEROES);