On Mon, Apr 25, 2022 at 11:08:03PM +0530, Kanchan Joshi wrote:
On Sat, Apr 23, 2022 at 07:53:09PM +0200, Christoph Hellwig wrote:
On Wed, Apr 06, 2022 at 10:50:14AM +0530, Kanchan Joshi wrote:
In that case we will base the newer version on its top.
But if it saves some cycles for you, and also the travel from nvme to
linux-block tree - I can carry that refactoring as a prep patch in
this series. Your call.
FYI, this is what I have so far:
http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/nvme-passthrough-refactor
the idea would be to use these lower level helpers for uring, and
not really share the higher level function at all. This does create
a little extra code, but I think it'll be more modular and better
maintainable. Feel free to pull this in if it helps you, otherwise
I'll try to find some time to do more than just light testing and
will post it.
Thanks for sharing.
So I had picked your previous version, and this one streamlines meta
handling further. But the problem is bip gets freed before we reach to
this point -
+static int nvme_free_user_metadata(struct bio *bio, void __user *ubuf, int ret)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ void *buf = bvec_virt(bip->bip_vec);
+
+ if (!ret && bio_op(bio) == REQ_OP_DRV_IN &&
+ copy_to_user(ubuf, buf, bip->bip_vec->bv_len))
Without bip, we cannot kill current meta/meta_len fields.
And by this I mean we cannot keep io_uring_cmd this way -
+struct io_uring_cmd {
+ struct file *file;
+ void *cmd;
+ /* for irq-completion - if driver requires doing stuff in task-context*/
+ void (*driver_cb)(struct io_uring_cmd *cmd);
+ u32 flags;
+ u32 cmd_op;
+
+ 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;
+};
Rather we need to backtrack to pdu[28], since nvme would need all that
space.
+struct io_uring_cmd {
+ struct file *file;
+ void *cmd;
+ /* for irq-completion - if driver requires doing stuff in task-context*/
+ void (*driver_cb)(struct io_uring_cmd *cmd);
+ u32 flags;
+ u32 cmd_op;
+ u32 unused;
+ u8 pdu[28]; /* available inline for free use */
+};
+struct nvme_uring_cmd_pdu {
+ union {
+ struct bio *bio;
+ struct request *req;
+ };
+ void *meta; /* kernel-resident buffer */
+ void __user *meta_buffer;
+ u32 meta_len;
+} __packed;
