[PATCH 2/2] io_uring: deduplicate io_grab_files() calls

Pavel Begunkov
2020-07-23T17:27:28Z

Move io_req_init_async() into io_grab_files(), it's safer this way. Note
that io_queue_async_work() does *init_async(), so it's valid to move out
of __io_queue_sqe() punt path. Also, add a helper around io_grab_files().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index bb356c56f57c..c22c2a3c8357 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -912,7 +912,7 @@ static void io_queue_linked_timeout(struct io_kiocb *req);
static int __io_sqe_files_update(struct io_ring_ctx *ctx,
struct io_uring_files_update *ip,
unsigned nr_args);
-static int io_grab_files(struct io_kiocb *req);
+static int io_prep_work_files(struct io_kiocb *req);
static void io_complete_rw_common(struct kiocb *kiocb, long res,
struct io_comp_state *cs);
static void __io_clean_op(struct io_kiocb *req);
@@ -5285,13 +5285,9 @@ static int io_req_defer_prep(struct io_kiocb *req,

if (io_alloc_async_ctx(req))
return -EAGAIN;
-
- if (io_op_defs[req->opcode].file_table) {
- io_req_init_async(req);
- ret = io_grab_files(req);
- if (unlikely(ret))
- return ret;
- }
+ ret = io_prep_work_files(req);
+ if (unlikely(ret))
+ return ret;

switch (req->opcode) {
case IORING_OP_NOP:
@@ -5842,6 +5838,8 @@ static int io_grab_files(struct io_kiocb *req)
int ret = -EBADF;
struct io_ring_ctx *ctx = req->ctx;

+ io_req_init_async(req);
+
if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
return 0;
if (!ctx->ring_file)
@@ -5867,6 +5865,13 @@ static int io_grab_files(struct io_kiocb *req)
return ret;
}

+static inline int io_prep_work_files(struct io_kiocb *req)
+{
+ if (!io_op_defs[req->opcode].file_table)
+ return 0;
+ return io_grab_files(req);
+}
+
static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
{
struct io_timeout_data *data = container_of(timer,
@@ -5978,14 +5983,9 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
goto exit;
}
punt:
- io_req_init_async(req);
-
- if (io_op_defs[req->opcode].file_table) {
- ret = io_grab_files(req);
- if (ret)
- goto err;
- }
-
+ ret = io_prep_work_files(req);
+ if (unlikely(ret))
+ goto err;
/*
* Queued up for async execution, worker will release
* submit reference when the iocb is actually submitted.
--
2.24.0