Instead of the magic pdu byte array, which in its current form causes
unaligned pointers and a lot of casting add explicit support for out
of band data in struct io_uring_cmd and just leave a normal private
data pointer to the driver.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/nvme/host/ioctl.c | 35 +++++++----------------------------
include/linux/io_uring.h | 10 ++++++++--
2 files changed, 15 insertions(+), 30 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index ea6cfd4321942..b93c6ecfcd2ab 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -37,27 +37,9 @@ static int nvme_ioctl_finish_metadata(struct bio *bio, int ret,
return ret;
}
-/*
- * This overlays struct io_uring_cmd pdu.
- * Expect build errors if this grows larger than that.
- */
-struct nvme_uring_cmd_pdu {
- union {
- struct bio *bio;
- struct request *req;
- };
- void __user *meta_buffer;
-} __packed;
-
-static struct nvme_uring_cmd_pdu *nvme_uring_cmd_pdu(struct io_uring_cmd *ioucmd)
-{
- return (struct nvme_uring_cmd_pdu *)&ioucmd->pdu;
-}
-
static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
{
- struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
- struct request *req = pdu->req;
+ struct request *req = ioucmd->private;
struct bio *bio = req->bio;
int status;
u64 result;
@@ -71,7 +53,7 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
blk_mq_free_request(req);
blk_rq_unmap_user(bio);
- status = nvme_ioctl_finish_metadata(bio, status, pdu->meta_buffer);
+ status = nvme_ioctl_finish_metadata(bio, status, ioucmd->oob_user);
result = le64_to_cpu(nvme_req(req)->result.u64);
io_uring_cmd_done(ioucmd, status, result);
}
@@ -79,12 +61,10 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
static void nvme_end_async_pt(struct request *req, blk_status_t err)
{
struct io_uring_cmd *ioucmd = req->end_io_data;
- struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
- /* extract bio before reusing the same field for request */
- struct bio *bio = pdu->bio;
+ struct bio *bio = ioucmd->private;
- pdu->req = req;
req->bio = bio;
+ ioucmd->private = req;
/* this takes care of moving rest of completion-work to task context */
io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
@@ -381,7 +361,6 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
{
struct nvme_passthru_cmd64 *cmd =
(struct nvme_passthru_cmd64 *)ioucmd->cmd;
- struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
struct request_queue *q = ns ? ns->queue : ctrl->admin_q;
struct nvme_command c;
struct request *req;
@@ -415,10 +394,10 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
return PTR_ERR(req);
/* to free bio on completion, as req->bio will be null at that time */
- pdu->bio = req->bio;
- pdu->meta_buffer = nvme_to_user_ptr(cmd->metadata);
- req->end_io_data = ioucmd;
+ ioucmd->private = req->bio;
+ ioucmd->oob_user = nvme_to_user_ptr(cmd->metadata);
+ req->end_io_data = ioucmd;
blk_execute_rq_nowait(req, 0, nvme_end_async_pt);
return -EIOCBQUEUED;
}
diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 0aba7b50cde65..95b56e45cd539 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -23,8 +23,14 @@ struct io_uring_cmd {
u32 flags;
u32 cmd_op;
u16 cmd_len;
- u16 unused;
- u8 pdu[28]; /* available inline for free use */
+
+ void *private;
+
+ /*
+ * Out of band data can be used for data that is not the main data.
+ * E.g. block device PI/metadata or additional information.
+ */
+ void __user *oob_user;
};
#if defined(CONFIG_IO_URING)
--
2.30.2
