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authorStefan Hajnoczi <stefanha@redhat.com>2020-04-08 10:11:39 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2020-04-09 15:55:06 +0100
commit636b836d5f4e36ceebb788e2e0d4724f7f9406e1 (patch)
tree93944141541d10969d8d4aba91068785271d2692 /util
parent8bac3ba57eecc466b7e73dabf7d19328a59f684e (diff)
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aio-posix: signal-proof fdmon-io_uring
The io_uring_enter(2) syscall returns with errno=EINTR when interrupted by a signal. Retry the syscall in this case. It's essential to do this in the io_uring_submit_and_wait() case. My interpretation of the Linux v5.5 io_uring_enter(2) code is that it shouldn't affect the io_uring_submit() case, but there is no guarantee this will always be the case. Let's check for -EINTR around both APIs. Note that the liburing APIs have -errno return values. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200408091139.273851-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'util')
-rw-r--r--util/fdmon-io_uring.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c
index b4d6109..d5a80ed 100644
--- a/util/fdmon-io_uring.c
+++ b/util/fdmon-io_uring.c
@@ -88,7 +88,10 @@ static struct io_uring_sqe *get_sqe(AioContext *ctx)
}
/* No free sqes left, submit pending sqes first */
- ret = io_uring_submit(ring);
+ do {
+ ret = io_uring_submit(ring);
+ } while (ret == -EINTR);
+
assert(ret > 1);
sqe = io_uring_get_sqe(ring);
assert(sqe);
@@ -282,7 +285,10 @@ static int fdmon_io_uring_wait(AioContext *ctx, AioHandlerList *ready_list,
fill_sq_ring(ctx);
- ret = io_uring_submit_and_wait(&ctx->fdmon_io_uring, wait_nr);
+ do {
+ ret = io_uring_submit_and_wait(&ctx->fdmon_io_uring, wait_nr);
+ } while (ret == -EINTR);
+
assert(ret >= 0);
return process_cq_ring(ctx, ready_list);