From e92adcba261fd391591bb63c1703185a04a41554 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Mon, 28 Apr 2008 02:12:04 -0700 Subject: [PATCH] aio: io_getevents() should return if io_destroy() is invoked This patch wakes up a thread waiting in io_getevents if another thread destroys the context. This was tested using a small program that spawns a thread to wait in io_getevents while the parent thread destroys the io context and then waits for the getevents thread to exit. Without this patch, the program hangs indefinitely. With the patch, the program exits as expected. Signed-off-by: Jeff Moyer Cc: Zach Brown Cc: Christopher Smith Cc: Benjamin LaHaise Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/aio.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/aio.c b/fs/aio.c index 228368610dfa..ae94e1dea266 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1166,7 +1166,10 @@ static int read_events(struct kioctx *ctx, 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 @@ -1231,6 +1234,13 @@ 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 */ }