io_uring: simplify overflow handling

Overflowed CQEs doesn't lock requests anymore, so we don't care so much
about cancelling them, so kill cq_overflow_flushed and simplify the
code.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5799867aeba9e713c32f49aef78e5e1aef9fbc43.1617287883.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 7c5c3d46c6b71794bc01b159f6ecb442ad7d0121..99f5252ff2dcbc99edb857c32d2c55c92af745e5 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -335,7 +335,6 @@ struct io_ring_ctx {
        struct {
                unsigned int            flags;
                unsigned int            compat: 1;
-               unsigned int            cq_overflow_flushed: 1;
                unsigned int            drain_next: 1;
                unsigned int            eventfd_async: 1;
                unsigned int            restricted: 1;
@@ -1525,8 +1524,7 @@ static bool __io_cqring_fill_event(struct io_kiocb *req, long res,
                WRITE_ONCE(cqe->flags, cflags);
                return true;
        }
-       if (!ctx->cq_overflow_flushed &&
-           !atomic_read(&req->task->io_uring->in_idle)) {
+       if (!atomic_read(&req->task->io_uring->in_idle)) {
                struct io_overflow_cqe *ocqe;
 
                ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);
@@ -8491,6 +8489,8 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
 
        mutex_lock(&ctx->uring_lock);
        io_sqe_files_unregister(ctx);
+       if (ctx->rings)
+               __io_cqring_overflow_flush(ctx, true);
        mutex_unlock(&ctx->uring_lock);
        io_eventfd_unregister(ctx);
        io_destroy_buffers(ctx);
@@ -8692,8 +8692,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
 
        mutex_lock(&ctx->uring_lock);
        percpu_ref_kill(&ctx->refs);
-       /* if force is set, the ring is going away. always drop after that */
-       ctx->cq_overflow_flushed = 1;
        if (ctx->rings)
                __io_cqring_overflow_flush(ctx, true);
        xa_for_each(&ctx->personalities, index, creds)