[PATCH] aio: Do not return -ERESTARTSYS (and friends) from AIO

[Jan Kara <jack@suse.cz>]

We must not leak ERESTARTSYS (and similar error codes) to userspace as a return
value of IO. Because other AIO could have been already submitted by the same
io_submit syscall, there is no easy way to restart the syscall. So we do not
have much other options than fail the particular IO with EINTR.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/aio.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

 Not sure who should merge it... Andrew?

diff --git a/fs/aio.c b/fs/aio.c
index 1ccf25c..66e2d42 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -712,8 +712,18 @@ static ssize_t aio_run_iocb(struct kiocb *iocb)
 	 */
 	ret = retry(iocb);
 
-	if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED)
+	if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED) {
+		/*
+		 * There's no easy way to restart the syscall since other AIO's
+		 * may be already running. Just fail this IO with EINTR.
+		 */
+		if (unlikely(ret == -ERESTARTSYS ||
+			     ret == -ERESTARTNOINTR ||
+			     ret == -ERESTARTNOHAND ||
+			     ret == -ERESTART_RESTARTBLOCK))
+			ret = -EINTR;
 		aio_complete(iocb, ret, 0);
+	}
 out:
 	spin_lock_irq(&ctx->ctx_lock);
 
-- 
1.6.4.2