io_uring: don't use kiocb.private to store buf_index

kiocb.private is used in iomap_dio_rw() so store buf_index separately.

Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Move 'buf_index' to a hole in io_kiocb.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 29aa530..d43f7e9 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -619,6 +619,8 @@ struct io_kiocb {
        bool                            needs_fixed_file;
        u8                              opcode;
 
+       u16                             buf_index;
+
        struct io_ring_ctx      *ctx;
        struct list_head        list;
        unsigned int            flags;
@@ -2101,9 +2103,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 
        req->rw.addr = READ_ONCE(sqe->addr);
        req->rw.len = READ_ONCE(sqe->len);
-       /* we own ->private, reuse it for the buffer index  / buffer ID */
-       req->rw.kiocb.private = (void *) (unsigned long)
-                                       READ_ONCE(sqe->buf_index);
+       req->buf_index = READ_ONCE(sqe->buf_index);
        return 0;
 }
 
@@ -2146,7 +2146,7 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
        struct io_ring_ctx *ctx = req->ctx;
        size_t len = req->rw.len;
        struct io_mapped_ubuf *imu;
-       unsigned index, buf_index;
+       u16 index, buf_index;
        size_t offset;
        u64 buf_addr;
 
@@ -2154,7 +2154,7 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
        if (unlikely(!ctx->user_bufs))
                return -EFAULT;
 
-       buf_index = (unsigned long) req->rw.kiocb.private;
+       buf_index = req->buf_index;
        if (unlikely(buf_index >= ctx->nr_user_bufs))
                return -EFAULT;
 
@@ -2270,10 +2270,10 @@ static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
                                        bool needs_lock)
 {
        struct io_buffer *kbuf;
-       int bgid;
+       u16 bgid;
 
        kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-       bgid = (int) (unsigned long) req->rw.kiocb.private;
+       bgid = req->buf_index;
        kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
        if (IS_ERR(kbuf))
                return kbuf;
@@ -2364,7 +2364,7 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
        }
 
        /* buffer index only valid with fixed read/write, or buffer select  */
-       if (req->rw.kiocb.private && !(req->flags & REQ_F_BUFFER_SELECT))
+       if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
                return -EINVAL;
 
        if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {