io_uring: add helper flushing locked_free_list

Add a new helper io_flush_cached_locked_reqs() that splices
locked_free_list to free_list, and does it right doing all sync and
invariant reinit.

Signed-off-by: Pavel Begunkov <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 08ab7c4..5eb12f4 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1628,6 +1628,15 @@ static void io_req_complete_failed(struct io_kiocb *req, long res)
        io_req_complete_post(req, res, 0);
 }
 
+static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
+                                       struct io_comp_state *cs)
+{
+       spin_lock_irq(&ctx->completion_lock);
+       list_splice_init(&cs->locked_free_list, &cs->free_list);
+       cs->locked_free_nr = 0;
+       spin_unlock_irq(&ctx->completion_lock);
+}
+
 /* Returns true IFF there are requests in the cache */
 static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
 {
@@ -1640,12 +1649,8 @@ static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
         * locked cache, grab the lock and move them over to our submission
         * side cache.
         */
-       if (READ_ONCE(cs->locked_free_nr) > IO_COMPL_BATCH) {
-               spin_lock_irq(&ctx->completion_lock);
-               list_splice_init(&cs->locked_free_list, &cs->free_list);
-               cs->locked_free_nr = 0;
-               spin_unlock_irq(&ctx->completion_lock);
-       }
+       if (READ_ONCE(cs->locked_free_nr) > IO_COMPL_BATCH)
+               io_flush_cached_locked_reqs(ctx, cs);
 
        nr = state->free_reqs;
        while (!list_empty(&cs->free_list)) {
@@ -8446,13 +8451,8 @@ static void io_req_caches_free(struct io_ring_ctx *ctx)
                submit_state->free_reqs = 0;
        }
 
-       spin_lock_irq(&ctx->completion_lock);
-       list_splice_init(&cs->locked_free_list, &cs->free_list);
-       cs->locked_free_nr = 0;
-       spin_unlock_irq(&ctx->completion_lock);
-
+       io_flush_cached_locked_reqs(ctx, cs);
        io_req_cache_free(&cs->free_list, NULL);
-
        mutex_unlock(&ctx->uring_lock);
 }