nvme: refactor nvme_submit_user_cmd()

Divide the work into two helpers, namely nvme_alloc_user_request and
nvme_execute_user_rq. This is a prep patch, to help wiring up
uring-cmd support in nvme.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[axboe: fold in fix for assuming bio is non-NULL]
Link: https://lore.kernel.org/r/20220511054750.20432-4-joshi.k@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 554566371ffa49cdc5629bd27a8dc5dd25318ccb..8d2569b656cce6bad44dba92d05000d33d5ce6d5 100644 (file)
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -53,10 +53,20 @@ out:
        return ERR_PTR(ret);
 }
 
-static int nvme_submit_user_cmd(struct request_queue *q,
+static int nvme_finish_user_metadata(struct request *req, void __user *ubuf,
+               void *meta, unsigned len, int ret)
+{
+       if (!ret && req_op(req) == REQ_OP_DRV_IN &&
+           copy_to_user(ubuf, meta, len))
+               ret = -EFAULT;
+       kfree(meta);
+       return ret;
+}
+
+static struct request *nvme_alloc_user_request(struct request_queue *q,
                struct nvme_command *cmd, void __user *ubuffer,
                unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
-               u32 meta_seed, u64 *result, unsigned timeout, bool vec)
+               u32 meta_seed, void **metap, unsigned timeout, bool vec)
 {
        bool write = nvme_is_write(cmd);
        struct nvme_ns *ns = q->queuedata;
@@ -68,7 +78,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
 
        req = blk_mq_alloc_request(q, nvme_req_op(cmd), 0);
        if (IS_ERR(req))
-               return PTR_ERR(req);
+               return req;
        nvme_init_request(req, cmd);
 
        if (timeout)
@@ -105,26 +115,50 @@ static int nvme_submit_user_cmd(struct request_queue *q,
                                goto out_unmap;
                        }
                        req->cmd_flags |= REQ_INTEGRITY;
+                       *metap = meta;
                }
        }
 
+       return req;
+
+out_unmap:
+       if (bio)
+               blk_rq_unmap_user(bio);
+out:
+       blk_mq_free_request(req);
+       return ERR_PTR(ret);
+}
+
+static int nvme_submit_user_cmd(struct request_queue *q,
+               struct nvme_command *cmd, void __user *ubuffer,
+               unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
+               u32 meta_seed, u64 *result, unsigned timeout, bool vec)
+{
+       struct request *req;
+       void *meta = NULL;
+       struct bio *bio;
+       int ret;
+
+       req = nvme_alloc_user_request(q, cmd, ubuffer, bufflen, meta_buffer,
+                       meta_len, meta_seed, &meta, timeout, vec);
+       if (IS_ERR(req))
+               return PTR_ERR(req);
+
+       bio = req->bio;
+
        ret = nvme_execute_passthru_rq(req);
+
        if (result)
                *result = le64_to_cpu(nvme_req(req)->result.u64);
-       if (meta && !ret && !write) {
-               if (copy_to_user(meta_buffer, meta, meta_len))
-                       ret = -EFAULT;
-       }
-       kfree(meta);
- out_unmap:
+       if (meta)
+               ret = nvme_finish_user_metadata(req, meta_buffer, meta,
+                                               meta_len, ret);
        if (bio)
                blk_rq_unmap_user(bio);
- out:
        blk_mq_free_request(req);
        return ret;
 }
 
-
 static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 {
        struct nvme_user_io io;