io_uring: increase max number of reg buffers

Since recent changes instead of storing a large array of struct
io_mapped_ubuf, we store pointers to them, that is 4 times slimmer and
we should not to so worry about restricting max number of registererd
buffer slots, increase the limit 4 times.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d3dee1da37f46da416aa96a16bf9e5094e10584d.1620990371.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 29ec5b2..e481ac8 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -100,6 +100,8 @@
 #define IORING_MAX_RESTRICTIONS        (IORING_RESTRICTION_LAST + \
                                 IORING_REGISTER_LAST + IORING_OP_LAST)
 
+#define IORING_MAX_REG_BUFFERS (1U << 14)
+
 #define SQE_VALID_FLAGS        (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
                                IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
                                IOSQE_BUFFER_SELECT)
@@ -8389,7 +8391,7 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
 
        if (ctx->user_bufs)
                return -EBUSY;
-       if (!nr_args || nr_args > UIO_MAXIOV)
+       if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
                return -EINVAL;
        ret = io_rsrc_node_switch_start(ctx);
        if (ret)