[PATCH v1 03/11] io_uring: change ring size calculation for CQE32

Stefan Roesch
2022-04-19T20:56:48Z

This changes the function rings_size to take large CQE's into account.

Co-developed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stefan Roesch <shr@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index bf2b02518332..9712483d3a17 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9693,8 +9693,8 @@ static void *io_mem_alloc(size_t size)
return (void *) __get_free_pages(gfp, get_order(size));
}

-static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
- size_t *sq_offset)
+static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries,
+ unsigned int cq_entries, size_t *sq_offset)
{
struct io_rings *rings;
size_t off, sq_array_size;
@@ -9702,6 +9702,10 @@ static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
off = struct_size(rings, cqes, cq_entries);
if (off == SIZE_MAX)
return SIZE_MAX;
+ if (ctx->flags & IORING_SETUP_CQE32) {
+ if (check_shl_overflow(off, 1, &off))
+ return SIZE_MAX;
+ }

#ifdef CONFIG_SMP
off = ALIGN(off, SMP_CACHE_BYTES);
@@ -11365,7 +11369,7 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
ctx->sq_entries = p->sq_entries;
ctx->cq_entries = p->cq_entries;

- size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
+ size = rings_size(ctx, p->sq_entries, p->cq_entries, &sq_array_offset);
if (size == SIZE_MAX)
return -EOVERFLOW;

--
2.30.2