io_uring: introduce io_prep_reg_iovec()

iovecs that are turned into registered buffers are imported in a special
way with an offset, so that later we can do an in place translation. Add
a helper function taking care of it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7de2ecb9ed5efc3c5cf320232236966da5ad4ccc.1741457480.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 9fa5c95708754da484dc0bbd0b42ce8c9f509be8..6b8dbadf445fbbce2e8caeef02ec7efc8c0c2441 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -403,9 +403,7 @@ static int io_sendmsg_zc_setup(struct io_kiocb *req, const struct io_uring_sqe *
        struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
        struct io_async_msghdr *kmsg = req->async_data;
        struct user_msghdr msg;
-       int ret, iovec_off;
-       struct iovec *iov;
-       void *res;
+       int ret;
 
        if (!(sr->flags & IORING_RECVSEND_FIXED_BUF))
                return io_sendmsg_setup(req, sqe);
@@ -416,24 +414,9 @@ static int io_sendmsg_zc_setup(struct io_kiocb *req, const struct io_uring_sqe *
        if (unlikely(ret))
                return ret;
        sr->msg_control = kmsg->msg.msg_control_user;
-
-       if (msg.msg_iovlen > kmsg->vec.nr || WARN_ON_ONCE(!kmsg->vec.iovec)) {
-               ret = io_vec_realloc(&kmsg->vec, msg.msg_iovlen);
-               if (ret)
-                       return ret;
-               req->flags |= REQ_F_NEED_CLEANUP;
-       }
-       iovec_off = kmsg->vec.nr - msg.msg_iovlen;
-       iov = kmsg->vec.iovec + iovec_off;
-
-       res = iovec_from_user(msg.msg_iov, msg.msg_iovlen, kmsg->vec.nr, iov,
-                             io_is_compat(req->ctx));
-       if (IS_ERR(res))
-               return PTR_ERR(res);
-
        kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen;
-       req->flags |= REQ_F_IMPORT_BUFFER;
-       return ret;
+
+       return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov, msg.msg_iovlen);
 }
 
 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 71fe47facd4c1df8a5deaca058de52702726af0a..0e413e910f3d10ad5782a279c582d162cf378ab3 100644 (file)
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1397,3 +1397,29 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
 
        return io_vec_fill_bvec(ddir, iter, imu, iov, nr_iovs, vec);
 }
+
+int io_prep_reg_iovec(struct io_kiocb *req, struct iou_vec *iv,
+                     const struct iovec __user *uvec, size_t uvec_segs)
+{
+       struct iovec *iov;
+       int iovec_off, ret;
+       void *res;
+
+       if (uvec_segs > iv->nr) {
+               ret = io_vec_realloc(iv, uvec_segs);
+               if (ret)
+                       return ret;
+               req->flags |= REQ_F_NEED_CLEANUP;
+       }
+
+       /* pad iovec to the right */
+       iovec_off = iv->nr - uvec_segs;
+       iov = iv->iovec + iovec_off;
+       res = iovec_from_user(uvec, uvec_segs, uvec_segs, iov,
+                             io_is_compat(req->ctx));
+       if (IS_ERR(res))
+               return PTR_ERR(res);
+
+       req->flags |= REQ_F_IMPORT_BUFFER;
+       return 0;
+}

diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index b0097c06b577e7fc9b7dba1d9b7f9f748548a7bb..43f784915573ddcb9c4bfeb999d088e394817bcf 100644 (file)
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -67,6 +67,8 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
                        struct io_kiocb *req, struct iou_vec *vec,
                        unsigned nr_iovs, unsigned iovec_off,
                        unsigned issue_flags);
+int io_prep_reg_iovec(struct io_kiocb *req, struct iou_vec *iv,
+                       const struct iovec __user *uvec, size_t uvec_segs);
 
 int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg);
 int io_sqe_buffers_unregister(struct io_ring_ctx *ctx);

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 50037313555f7ad7cdf89a82c7ed78237c292dce..4861b876f48e358ff961d198d1b905f5cf52ef99 100644 (file)
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -407,28 +407,9 @@ static int io_rw_prep_reg_vec(struct io_kiocb *req)
        struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
        struct io_async_rw *io = req->async_data;
        const struct iovec __user *uvec;
-       size_t uvec_segs = rw->len;
-       struct iovec *iov;
-       int iovec_off, ret;
-       void *res;
 
-       if (uvec_segs > io->vec.nr) {
-               ret = io_vec_realloc(&io->vec, uvec_segs);
-               if (ret)
-                       return ret;
-               req->flags |= REQ_F_NEED_CLEANUP;
-       }
-       /* pad iovec to the right */
-       iovec_off = io->vec.nr - uvec_segs;
-       iov = io->vec.iovec + iovec_off;
        uvec = u64_to_user_ptr(rw->addr);
-       res = iovec_from_user(uvec, uvec_segs, uvec_segs, iov,
-                             io_is_compat(req->ctx));
-       if (IS_ERR(res))
-               return PTR_ERR(res);
-
-       req->flags |= REQ_F_IMPORT_BUFFER;
-       return 0;
+       return io_prep_reg_iovec(req, &io->vec, uvec, rw->len);
 }
 
 int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe)