Re: [PATCH v6 06/10] io_uring/rw: add support to send metadata along with read/write
From: Keith Busch <kbusch@kernel.org>
Date: 2024-10-30 21:09:30
Also in:
io-uring, linux-fsdevel, linux-nvme, linux-scsi
On Wed, Oct 30, 2024 at 11:31:08PM +0530, Kanchan Joshi wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 024745283783..48dcca125db3 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h@@ -105,6 +105,22 @@ struct io_uring_sqe { */ __u8 cmd[0]; }; + /* + * If the ring is initialized with IORING_SETUP_SQE128, then + * this field is starting offset for 64 bytes of data. For meta io + * this contains 'struct io_uring_meta_pi' + */ + __u8 big_sqe[0]; +}; + +/* this is placed in SQE128 */ +struct io_uring_meta_pi { + __u16 pi_flags; + __u16 app_tag; + __u32 len; + __u64 addr; + __u64 seed; + __u64 rsvd[2]; };
On the previous version, I was more questioning if it aligns with what
Pavel was trying to do here. I didn't quite get it, so I was more
confused than saying it should be this way now.
But I personally think this path makes sense. I would set it up just a
little differently for extended sqe's so that the PI overlays a more
generic struct that other opcodes might find a way to use later.
Something like:
struct io_uring_sqe_ext {
union {
__u32 rsvd0[8];
struct {
__u16 pi_flags;
__u16 app_tag;
__u32 len;
__u64 addr;
__u64 seed;
} rw_pi;
};
__u32 rsvd1[8];
};
quoted hunk ↗ jump to hunk
@@ -3902,6 +3903,9 @@ static int __init io_uring_init(void) /* top 8bits are for internal use */ BUILD_BUG_ON((IORING_URING_CMD_MASK & 0xff000000) != 0); + BUILD_BUG_ON(sizeof(struct io_uring_meta_pi) > + sizeof(struct io_uring_sqe));
Then this check would become: BUILD_BUG_ON(sizeof(struct io_uring_sqe_ext) != sizeof(struct io_uring_sqe));