io_uring: add helper calculating region byte size

There has been type related issues with region size calculation, add an
utility helper function that returns the size and handles type
conversions right.

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

diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index 24da17a5f08f9738990c03bc521d06044e59fb9e..dc4bfc5b6fb8125bbd4577bfbd76cbd078a86fdc 100644 (file)
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -134,7 +134,7 @@ static int io_region_init_ptr(struct io_mapped_region *mr)
 static int io_region_pin_pages(struct io_mapped_region *mr,
                               struct io_uring_region_desc *reg)
 {
-       unsigned long size = mr->nr_pages << PAGE_SHIFT;
+       size_t size = io_region_size(mr);
        struct page **pages;
        int nr_pages;
 
@@ -154,7 +154,7 @@ static int io_region_allocate_pages(struct io_mapped_region *mr,
                                    unsigned long mmap_offset)
 {
        gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN;
-       size_t size = (size_t) mr->nr_pages << PAGE_SHIFT;
+       size_t size = io_region_size(mr);
        unsigned long nr_allocated;
        struct page **pages;
 

diff --git a/io_uring/memmap.h b/io_uring/memmap.h
index a6c63ca2c6f1f33befe549e3371097f968fa7d97..a39d9e518905f760bb69b5d37d9892391fb937f7 100644 (file)
--- a/io_uring/memmap.h
+++ b/io_uring/memmap.h
@@ -43,4 +43,9 @@ static inline void io_region_publish(struct io_ring_ctx *ctx,
        *dst_region = *src_region;
 }
 
+static inline size_t io_region_size(struct io_mapped_region *mr)
+{
+       return (size_t) mr->nr_pages << PAGE_SHIFT;
+}
+
 #endif