tcp: allow splice() to build full TSO packets

[firefly-linux-kernel-4.4.55.git] / fs / aio.c

diff --git a/fs/aio.c b/fs/aio.c
index e29ec485af255822b8414be128fc8ef66da9a204..b4a88ccf777e7cb3be5a90e0e347ebacf6234b67 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -228,12 +228,6 @@ static void __put_ioctx(struct kioctx *ctx)
        call_rcu(&ctx->rcu_head, ctx_rcu_free);
 }
 
-static inline void get_ioctx(struct kioctx *kioctx)
-{
-       BUG_ON(atomic_read(&kioctx->users) <= 0);
-       atomic_inc(&kioctx->users);
-}
-
 static inline int try_get_ioctx(struct kioctx *kioctx)
 {
        return atomic_inc_not_zero(&kioctx->users);
@@ -273,7 +267,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
        mm = ctx->mm = current->mm;
        atomic_inc(&mm->mm_count);
 
-       atomic_set(&ctx->users, 1);
+       atomic_set(&ctx->users, 2);
        spin_lock_init(&ctx->ctx_lock);
        spin_lock_init(&ctx->ring_info.ring_lock);
        init_waitqueue_head(&ctx->wait);
@@ -527,11 +521,16 @@ static void aio_fput_routine(struct work_struct *data)
                        fput(req->ki_filp);
 
                /* Link the iocb into the context's free list */
+               rcu_read_lock();
                spin_lock_irq(&ctx->ctx_lock);
                really_put_req(ctx, req);
+               /*
+                * at that point ctx might've been killed, but actual
+                * freeing is RCU'd
+                */
                spin_unlock_irq(&ctx->ctx_lock);
+               rcu_read_unlock();
 
-               put_ioctx(ctx);
                spin_lock_irq(&fput_lock);
        }
        spin_unlock_irq(&fput_lock);
@@ -562,7 +561,6 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req)
         * this function will be executed w/out any aio kthread wakeup.
         */
        if (unlikely(!fput_atomic(req->ki_filp))) {
-               get_ioctx(ctx);
                spin_lock(&fput_lock);
                list_add(&req->ki_list, &fput_head);
                spin_unlock(&fput_lock);
@@ -1256,10 +1254,10 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
        ret = PTR_ERR(ioctx);
        if (!IS_ERR(ioctx)) {
                ret = put_user(ioctx->user_id, ctxp);
-               if (!ret)
+               if (!ret) {
+                       put_ioctx(ioctx);
                        return 0;
-
-               get_ioctx(ioctx); /* io_destroy() expects us to hold a ref */
+               }
                io_destroy(ioctx);
        }