6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Maurizio Lombardi mlombard@redhat.com
[ Upstream commit 88c23a32b851e36adc4ab36f796d9b711f47e2bb ]
The NVMe specification states that MAXCMD is mandatory for NVMe-over-Fabrics implementations. However, some NVMe/TCP and NVMe/FC arrays from major vendors have buggy firmware that reports MAXCMD as zero in the Identify Controller data structure.
Currently, the implementation closes the connection in such cases, completely preventing the host from connecting to the target.
Fix the issue by printing a clear error message about the firmware bug and allowing the connection to proceed. It assumes that the target supports a MAXCMD value of SQSIZE + 1. If any issues arise, the user can manually adjust SQSIZE to mitigate them.
Fixes: 4999568184e5 ("nvme-fabrics: check max outstanding commands") Signed-off-by: Maurizio Lombardi mlombard@redhat.com Reviewed-by: Laurence Oberman loberman@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index fe83d31ac928b..ec03b25eacbbc 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3251,8 +3251,9 @@ static int nvme_check_ctrl_fabric_info(struct nvme_ctrl *ctrl, struct nvme_id_ct }
if (!ctrl->maxcmd) { - dev_err(ctrl->device, "Maximum outstanding commands is 0\n"); - return -EINVAL; + dev_warn(ctrl->device, + "Firmware bug: maximum outstanding commands is 0\n"); + ctrl->maxcmd = ctrl->sqsize + 1; }
return 0;