[PATCH V3 10/13] md: use time_is_before_eq_jiffies() instead of open coding it

[Qing Wang <wangqing@xxxxxxxx>]

From: Wang Qing <wangqing@xxxxxxxx>

Use the helper function time_is_{before,after}_jiffies() to improve
code readability.

Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
---
 drivers/md/dm-writecache.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 5630b47..125bb5d
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -16,6 +16,7 @@
 #include <linux/pfn_t.h>
 #include <linux/libnvdimm.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include "dm-io-tracker.h"
 
 #define DM_MSG_PREFIX "writecache"
@@ -1971,8 +1972,8 @@ static void writecache_writeback(struct work_struct *work)
        while (!list_empty(&wc->lru) &&
               (wc->writeback_all ||
                wc->freelist_size + wc->writeback_size <= 
wc->freelist_low_watermark ||
-               (jiffies - container_of(wc->lru.prev, struct wc_entry, 
lru)->age >=
-                wc->max_age - wc->max_age / MAX_AGE_DIV))) {
+               time_is_before_eq_jiffies(container_of(wc->lru.prev, struct 
wc_entry, lru)->age
+                 + wc->max_age - wc->max_age / MAX_AGE_DIV)) {
 
                n_walked++;
                if (unlikely(n_walked > WRITEBACK_LATENCY) &&
-- 
2.7.4