[PATCHv2 4/4] zram: report failed read and writes stats

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

zram accounted but did not report numbers of failed read
and write queries. make these stats available as failed_reads
and failed_writes attrs.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
 drivers/block/zram/zram_drv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6eb2155..ce00d47 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -699,6 +699,8 @@ static DEVICE_ATTR(memory_used, S_IRUGO, memory_used_show, NULL);
 
 ZRAM_ATTR_RO(num_reads);
 ZRAM_ATTR_RO(num_writes);
+ZRAM_ATTR_RO(failed_reads);
+ZRAM_ATTR_RO(failed_writes);
 ZRAM_ATTR_RO(pages_stored);
 ZRAM_ATTR_RO(invalid_io);
 ZRAM_ATTR_RO(notify_free);
@@ -711,6 +713,8 @@ static struct attribute *zram_disk_attrs[] = {
 	&dev_attr_reset.attr,
 	&dev_attr_num_reads.attr,
 	&dev_attr_num_writes.attr,
+	&dev_attr_failed_reads.attr,
+	&dev_attr_failed_writes.attr,
 	&dev_attr_pages_stored.attr,
 	&dev_attr_invalid_io.attr,
 	&dev_attr_notify_free.attr,
-- 
1.8.5.3.493.gb139ac2