[PATCH 16/19] io_uring: add io_kiocb ref count
From: Jens Axboe <axboe@kernel.dk>
Date: 2019-02-08 17:35:10
Also in:
linux-block
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
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 <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> --- 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
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