Fix occasional rsend test crashes

We have occasional crashes in the rsend tests. Debugging revealed that this is because the send_worker thread is getting EINTR from splice(). This happens when a non-fatal signal is received during the syscall. We should retry the syscall, rather than exiting failure. Tweak the loop to only break if the splice is finished or we receive a non-EINTR error. Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Ahelenia Ziemiańska <[email protected]> Signed-off-by: Paul Dagnelie <[email protected]> Closes openzfs#15273
behlendorf · Sep 20, 2023 · 3c57fe1 · 3c57fe1
1 parent e9a6618
commit 3c57fe1
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/lib/libzfs_core/libzfs_core.c b/lib/libzfs_core/libzfs_core.c
@@ -650,10 +650,12 @@ send_worker(void *arg)
 	unsigned int bufsiz = max_pipe_buffer(ctx->from);
 	ssize_t rd;
 
-	while ((rd = splice(ctx->from, NULL, ctx->to, NULL, bufsiz,
-	    SPLICE_F_MOVE | SPLICE_F_MORE)) > 0)
-		;
-
+	for (;;) {
+		rd = splice(ctx->from, NULL, ctx->to, NULL, bufsiz,
+		    SPLICE_F_MOVE | SPLICE_F_MORE);
+		if ((rd == -1 && errno != EINTR) || rd == 0)
+			break;
+	}
 	int err = (rd == -1) ? errno : 0;
 	close(ctx->from);
 	return ((void *)(uintptr_t)err);