[12/12] aio-posix: Assert that aio_poll() is always called in home thread
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Message ID 20190218161822.3573-13-kwolf@redhat.com
State New
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Series
  • block: bdrv_set_aio_context() related fixes
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Commit Message

Kevin Wolf Feb. 18, 2019, 4:18 p.m. UTC
aio_poll() has an existing assertion that the function is only called
from the AioContext's home thread if blocking is allowed.

This is not enough, some handlers make assumptions about the thread they
run in. Extend the assertion to non-blocking calls, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 util/aio-posix.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Eric Blake Feb. 18, 2019, 8:58 p.m. UTC | #1
On 2/18/19 10:18 AM, Kevin Wolf wrote:
> aio_poll() has an existing assertion that the function is only called
> from the AioContext's home thread if blocking is allowed.
> 
> This is not enough, some handlers make assumptions about the thread they
> run in. Extend the assertion to non-blocking calls, too.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  util/aio-posix.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

> diff --git a/util/aio-posix.c b/util/aio-posix.c
> index 8640dfde9f..6fbfa7924f 100644
> --- a/util/aio-posix.c
> +++ b/util/aio-posix.c
> @@ -613,6 +613,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
>      int64_t timeout;
>      int64_t start = 0;
>  
> +    assert(in_aio_context_home_thread(ctx));
> +
>      /* aio_notify can avoid the expensive event_notifier_set if
>       * everything (file descriptors, bottom halves, timers) will
>       * be re-evaluated before the next blocking poll().  This is
> @@ -621,7 +623,6 @@ bool aio_poll(AioContext *ctx, bool blocking)
>       * so disable the optimization now.
>       */
>      if (blocking) {
> -        assert(in_aio_context_home_thread(ctx));
>          atomic_add(&ctx->notify_me, 2);
>      }
>  
>

Patch
diff mbox series

diff --git a/util/aio-posix.c b/util/aio-posix.c
index 8640dfde9f..6fbfa7924f 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -613,6 +613,8 @@  bool aio_poll(AioContext *ctx, bool blocking)
     int64_t timeout;
     int64_t start = 0;
 
+    assert(in_aio_context_home_thread(ctx));
+
     /* aio_notify can avoid the expensive event_notifier_set if
      * everything (file descriptors, bottom halves, timers) will
      * be re-evaluated before the next blocking poll().  This is
@@ -621,7 +623,6 @@  bool aio_poll(AioContext *ctx, bool blocking)
      * so disable the optimization now.
      */
     if (blocking) {
-        assert(in_aio_context_home_thread(ctx));
         atomic_add(&ctx->notify_me, 2);
     }