io_uring: add task-refs-get helper

As we have a more complicated task referencing, which apart from normal
task references includes taking tctx->inflight and caching all that, it
would be a good idea to have all that isolated in helpers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d9114d037f1c195897aa13f38a496078eca2afdb.1630023531.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1341b71..5059049 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1670,6 +1670,24 @@ static inline void io_put_task(struct task_struct *task, int nr)
        }
 }
 
+static void io_task_refs_refill(struct io_uring_task *tctx)
+{
+       unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
+
+       percpu_counter_add(&tctx->inflight, refill);
+       refcount_add(refill, &current->usage);
+       tctx->cached_refs += refill;
+}
+
+static inline void io_get_task_refs(int nr)
+{
+       struct io_uring_task *tctx = current->io_uring;
+
+       tctx->cached_refs -= nr;
+       if (unlikely(tctx->cached_refs < 0))
+               io_task_refs_refill(tctx);
+}
+
 static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
                                     long res, unsigned int cflags)
 {
@@ -6890,25 +6908,15 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
 static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
        __must_hold(&ctx->uring_lock)
 {
-       struct io_uring_task *tctx;
        int submitted = 0;
 
        /* make sure SQ entry isn't read before tail */
        nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
        if (!percpu_ref_tryget_many(&ctx->refs, nr))
                return -EAGAIN;
+       io_get_task_refs(nr);
 
-       tctx = current->io_uring;
-       tctx->cached_refs -= nr;
-       if (unlikely(tctx->cached_refs < 0)) {
-               unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
-
-               percpu_counter_add(&tctx->inflight, refill);
-               refcount_add(refill, &current->usage);
-               tctx->cached_refs += refill;
-       }
        io_submit_state_start(&ctx->submit_state, nr);
-
        while (submitted < nr) {
                const struct io_uring_sqe *sqe;
                struct io_kiocb *req;