Merge commit 'linus/master' into sched-fixes-for-linus

[pandora-kernel.git] / fs / aio.c

diff --git a/fs/aio.c b/fs/aio.c
index 2283686..b5253e7 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -191,6 +191,43 @@ static int aio_setup_ring(struct kioctx *ctx)
        kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK), km); \
 } while(0)
 
+
+/* __put_ioctx
+ *     Called when the last user of an aio context has gone away,
+ *     and the struct needs to be freed.
+ */
+static void __put_ioctx(struct kioctx *ctx)
+{
+       unsigned nr_events = ctx->max_reqs;
+
+       BUG_ON(ctx->reqs_active);
+
+       cancel_delayed_work(&ctx->wq);
+       cancel_work_sync(&ctx->wq.work);
+       aio_free_ring(ctx);
+       mmdrop(ctx->mm);
+       ctx->mm = NULL;
+       pr_debug("__put_ioctx: freeing %p\n", ctx);
+       kmem_cache_free(kioctx_cachep, ctx);
+
+       if (nr_events) {
+               spin_lock(&aio_nr_lock);
+               BUG_ON(aio_nr - nr_events > aio_nr);
+               aio_nr -= nr_events;
+               spin_unlock(&aio_nr_lock);
+       }
+}
+
+#define get_ioctx(kioctx) do {                                         \
+       BUG_ON(atomic_read(&(kioctx)->users) <= 0);                     \
+       atomic_inc(&(kioctx)->users);                                   \
+} while (0)
+#define put_ioctx(kioctx) do {                                         \
+       BUG_ON(atomic_read(&(kioctx)->users) <= 0);                     \
+       if (unlikely(atomic_dec_and_test(&(kioctx)->users)))            \
+               __put_ioctx(kioctx);                                    \
+} while (0)
+
 /* ioctx_alloc
  *     Allocates and initializes an ioctx.  Returns an ERR_PTR if it failed.
  */
@@ -240,7 +277,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
        if (ctx->max_reqs == 0)
                goto out_cleanup;
 
-       /* now link into global list.  kludge.  FIXME */
+       /* now link into global list. */
        write_lock(&mm->ioctx_list_lock);
        ctx->next = mm->ioctx_list;
        mm->ioctx_list = ctx;
@@ -361,32 +398,6 @@ void exit_aio(struct mm_struct *mm)
        }
 }
 
-/* __put_ioctx
- *     Called when the last user of an aio context has gone away,
- *     and the struct needs to be freed.
- */
-void __put_ioctx(struct kioctx *ctx)
-{
-       unsigned nr_events = ctx->max_reqs;
-
-       BUG_ON(ctx->reqs_active);
-
-       cancel_delayed_work(&ctx->wq);
-       cancel_work_sync(&ctx->wq.work);
-       aio_free_ring(ctx);
-       mmdrop(ctx->mm);
-       ctx->mm = NULL;
-       pr_debug("__put_ioctx: freeing %p\n", ctx);
-       kmem_cache_free(kioctx_cachep, ctx);
-
-       if (nr_events) {
-               spin_lock(&aio_nr_lock);
-               BUG_ON(aio_nr - nr_events > aio_nr);
-               aio_nr -= nr_events;
-               spin_unlock(&aio_nr_lock);
-       }
-}
-
 /* aio_get_req
  *     Allocate a slot for an aio request.  Increments the users count
  * of the kioctx so that the kioctx stays around until all requests are
@@ -542,10 +553,7 @@ int aio_put_req(struct kiocb *req)
        return ret;
 }
 
-/*     Lookup an ioctx id.  ioctx_list is lockless for reads.
- *     FIXME: this is O(n) and is only suitable for development.
- */
-struct kioctx *lookup_ioctx(unsigned long ctx_id)
+static struct kioctx *lookup_ioctx(unsigned long ctx_id)
 {
        struct kioctx *ioctx;
        struct mm_struct *mm;
@@ -1070,9 +1078,7 @@ static void timeout_func(unsigned long data)
 
 static inline void init_timeout(struct aio_timeout *to)
 {
-       init_timer(&to->timer);
-       to->timer.data = (unsigned long)to;
-       to->timer.function = timeout_func;
+       setup_timer_on_stack(&to->timer, timeout_func, (unsigned long) to);
        to->timed_out = 0;
        to->p = current;
 }
@@ -1166,7 +1172,10 @@ retry:
                                break;
                        if (min_nr <= i)
                                break;
-                       ret = 0;
+                       if (unlikely(ctx->dead)) {
+                               ret = -EINVAL;
+                               break;
+                       }
                        if (to.timed_out)       /* Only check after read evt */
                                break;
                        /* Try to only show up in io wait if there are ops
@@ -1202,6 +1211,7 @@ retry:
        if (timeout)
                clear_timeout(&to);
 out:
+       destroy_timer_on_stack(&to.timer);
        return i ? i : ret;
 }
 
@@ -1231,6 +1241,13 @@ static void io_destroy(struct kioctx *ioctx)
 
        aio_cancel_all(ioctx);
        wait_for_all_aios(ioctx);
+
+       /*
+        * Wake up any waiters.  The setting of ctx->dead must be seen
+        * by other CPUs at this point.  Right now, we rely on the
+        * locking done by the above calls to ensure this consistency.
+        */
+       wake_up(&ioctx->wait);
        put_ioctx(ioctx);       /* once for the lookup */
 }
 
@@ -1542,7 +1559,7 @@ static int aio_wake_function(wait_queue_t *wait, unsigned mode,
        return 1;
 }
 
-int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
+static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
                         struct iocb *iocb)
 {
        struct kiocb *req;
@@ -1583,7 +1600,7 @@ int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
                 * event using the eventfd_signal() function.
                 */
                req->ki_eventfd = eventfd_fget((int) iocb->aio_resfd);
-               if (unlikely(IS_ERR(req->ki_eventfd))) {
+               if (IS_ERR(req->ki_eventfd)) {
                        ret = PTR_ERR(req->ki_eventfd);
                        goto out_put_req;
                }