From: Xinyu Zhang xizhang@purestorage.com
[ Upstream commit 99fde895ff56ac2241e7b7b4566731d72f2fdaa7 ]
When using kernel registered bvec fixed buffers, the "address" is actually the offset into the bvec rather than userspace address. Therefore it can be 0.
We can skip checking whether the address is NULL before mapping uring_cmd data. Bad userspace address will be handled properly later when the user buffer is imported.
With this patch, we will be able to use the kernel registered bvec fixed buffers in io_uring NVMe passthru with ublk zero-copy support.
Reviewed-by: Caleb Sander Mateos csander@purestorage.com Reviewed-by: Jens Axboe axboe@kernel.dk Reviewed-by: Ming Lei ming.lei@redhat.com Signed-off-by: Xinyu Zhang xizhang@purestorage.com Signed-off-by: Keith Busch kbusch@kernel.org Link: https://lore.kernel.org/r/20250227223916.143006-4-kbusch@meta.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index 4ce31f9f06947..83908f2dd07fe 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -618,7 +618,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns, return PTR_ERR(req); req->timeout = d.timeout_ms ? msecs_to_jiffies(d.timeout_ms) : 0;
- if (d.addr && d.data_len) { + if (d.data_len) { ret = nvme_map_user_request(req, d.addr, d.data_len, nvme_to_user_ptr(d.metadata), d.metadata_len, 0, &meta, ioucmd, vec);