We'll use this for the POLL implementation. Regular requests will NOT be using references, so initialize it to 0. Any real use of the io_kiocb ref will initialize it to at least 2.
Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Jens Axboe <[email protected]> --- fs/io_uring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index e6b9cef4665d..9b28f2cd29db 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -163,6 +163,7 @@ struct io_kiocb { struct io_ring_ctx *ctx; struct list_head list; unsigned int flags; + refcount_t refs; #define REQ_F_FORCE_NONBLOCK 1 /* inline submission attempt */ #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ #define REQ_F_FIXED_FILE 4 /* ctx owns file */ @@ -349,6 +350,7 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, req->ctx = ctx; req->flags = 0; + refcount_set(&req->refs, 0); return req; out: io_ring_drop_ctx_refs(ctx, 1); @@ -366,8 +368,10 @@ static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) static void io_free_req(struct io_kiocb *req) { - io_ring_drop_ctx_refs(req->ctx, 1); - kmem_cache_free(req_cachep, req); + if (!refcount_read(&req->refs) || refcount_dec_and_test(&req->refs)) { + io_ring_drop_ctx_refs(req->ctx, 1); + kmem_cache_free(req_cachep, req); + } } /* -- 2.17.1
