From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 30 Sep 2013 18:17:34 +0000 (-0600)
Subject: log: disable log, if realloc fails
X-Git-Tag: fio-2.1.4~23
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=3c568239a319087a965b06bc2ed94d058810100f

log: disable log, if realloc fails

Right now we just segfault, if realloc() returns NULL. Handle
this a bit more gracefully, by just disabling logging if that
happens. Fio will also print an error for that case.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/iolog.h b/iolog.h
index 8fedc192..6503acff 100644
--- a/iolog.h
+++ b/iolog.h
@@ -49,6 +49,11 @@ struct io_log {
 
 	unsigned int log_type;
 
+	/*
+	 * If we fail extending the log, stop collecting more entries.
+	 */
+	unsigned int disabled;
+
 	/*
 	 * Windowed average, for logging single entries average over some
 	 * period of time.
diff --git a/stat.c b/stat.c
index 10d9efea..fec36396 100644
--- a/stat.c
+++ b/stat.c
@@ -1504,13 +1504,23 @@ static void __add_log_sample(struct io_log *iolog, unsigned long val,
 {
 	const int nr_samples = iolog->nr_samples;
 
+	if (iolog->disabled)
+		return;
+
 	if (!iolog->nr_samples)
 		iolog->avg_last = t;
 
 	if (iolog->nr_samples == iolog->max_samples) {
 		int new_size = sizeof(struct io_sample) * iolog->max_samples*2;
+		void *new_log;
 
-		iolog->log = realloc(iolog->log, new_size);
+		new_log = realloc(iolog->log, new_size);
+		if (!new_log) {
+			log_err("fio: failed extending iolog! Will stop logging.\n");
+			iolog->disabled = 1;
+			return;
+		}
+		iolog->log = new_log;
 		iolog->max_samples <<= 1;
 	}