io_uring/rsrc: replace reg buffer bit field with flags

I'll need a flag in the registered buffer struct for dmabuf work, and
it'll be more convenient to have a flags field rather than bit fields,
especially for io_mapped_ubuf initialisation.

We might want to add more flags in the future as well. For example, it
might be useful for debugging and potentially optimisations to split out
a flag indicating the shape of the buffer to gate iov_iter_advance()
walks vs bit/mask arithmetics. It can also be combined with the
direction mask field.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 95ce553fff8d1f0016d8d8ae133e0b4a101aa540..05f00bdb02d7cdde8bac6f5f27a601438ce0dc3d 100644 (file)
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -828,7 +828,7 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx,
        imu->folio_shift = PAGE_SHIFT;
        imu->release = io_release_ubuf;
        imu->priv = imu;
-       imu->is_kbuf = false;
+       imu->flags = 0;
        imu->dir = IO_IMU_DEST | IO_IMU_SOURCE;
        if (coalesced)
                imu->folio_shift = data.folio_shift;
@@ -985,7 +985,7 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
        refcount_set(&imu->refs, 1);
        imu->release = release;
        imu->priv = rq;
-       imu->is_kbuf = true;
+       imu->flags = IO_REGBUF_F_KBUF;
        imu->dir = 1 << rq_data_dir(rq);
 
        rq_for_each_bvec(bv, rq, rq_iter)
@@ -1020,7 +1020,7 @@ int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
                ret = -EINVAL;
                goto unlock;
        }
-       if (!node->buf->is_kbuf) {
+       if (!(node->buf->flags & IO_REGBUF_F_KBUF)) {
                ret = -EBUSY;
                goto unlock;
        }
@@ -1076,7 +1076,7 @@ static int io_import_fixed(int ddir, struct iov_iter *iter,
 
        offset = buf_addr - imu->ubuf;
 
-       if (imu->is_kbuf)
+       if (imu->flags & IO_REGBUF_F_KBUF)
                return io_import_kbuf(ddir, iter, imu, len, offset);
 
        /*
@@ -1496,7 +1496,7 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
        iovec_off = vec->nr - nr_iovs;
        iov = vec->iovec + iovec_off;
 
-       if (imu->is_kbuf) {
+       if (imu->flags & IO_REGBUF_F_KBUF) {
                int ret = io_kern_bvec_size(iov, nr_iovs, imu, &nr_segs);
 
                if (unlikely(ret))
@@ -1534,7 +1534,7 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
                req->flags |= REQ_F_NEED_CLEANUP;
        }
 
-       if (imu->is_kbuf)
+       if (imu->flags & IO_REGBUF_F_KBUF)
                return io_vec_fill_kern_bvec(ddir, iter, imu, iov, nr_iovs, vec);
 
        return io_vec_fill_bvec(ddir, iter, imu, iov, nr_iovs, vec);

diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 4a5db2ad1af2cd82772dd6d937713bbfeee2c922..cff0f8834c353de624cbbc53d9f8ac04eed59717 100644 (file)
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -28,6 +28,10 @@ enum {
        IO_IMU_SOURCE   = 1 << ITER_SOURCE,
 };
 
+enum {
+       IO_REGBUF_F_KBUF                = 1,
+};
+
 struct io_mapped_ubuf {
        u64             ubuf;
        unsigned int    len;
@@ -37,7 +41,7 @@ struct io_mapped_ubuf {
        unsigned long   acct_pages;
        void            (*release)(void *);
        void            *priv;
-       bool            is_kbuf;
+       u8              flags;
        u8              dir;
        struct bio_vec  bvec[] __counted_by(nr_bvecs);
 };

diff --git a/io_uring/rw.c b/io_uring/rw.c
index d10386f56d49eb087bb129492003b6c66d1931c2..b3971171c3422dcfe76b153eb6ce2853397fc679 100644 (file)
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -702,7 +702,8 @@ static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
        if ((kiocb->ki_flags & IOCB_NOWAIT) &&
            !(kiocb->ki_filp->f_flags & O_NONBLOCK))
                return -EAGAIN;
-       if ((req->flags & REQ_F_BUF_NODE) && req->buf_node->buf->is_kbuf)
+       if ((req->flags & REQ_F_BUF_NODE) &&
+            (req->buf_node->buf->flags & IO_REGBUF_F_KBUF))
                return -EFAULT;
 
        ppos = io_kiocb_ppos(kiocb);