From: Stefan Behrens <sbehrens@giantdisaster.de>
Date: Tue, 17 Jul 2012 15:02:11 +0000 (-0600)
Subject: Btrfs: suppress printk() if all device I/O stats are zero
X-Git-Tag: v3.6-rc1~81^2~11
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=a98cdb85b990765dbe80a215367ae007320bfeea;p=~emulex%2Finfiniband.git

Btrfs: suppress printk() if all device I/O stats are zero

Code is added to suppress the I/O stats printing at mount time if all
statistic values are zero.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 14436074350..b8708f994e6 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4884,6 +4884,14 @@ void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
 
 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
 {
+	int i;
+
+	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+		if (btrfs_dev_stat_read(dev, i) != 0)
+			break;
+	if (i == BTRFS_DEV_STAT_VALUES_MAX)
+		return; /* all values == 0, suppress message */
+
 	printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
 	       rcu_str_deref(dev->name),
 	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),