[PATCH] dcache.c: Replace smp_read_barrier_depends() with lockless_dereference()

From: He Kuang
Date: Sat Mar 26 2016 - 05:23:56 EST


lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the
change.

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
---
fs/dcache.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 32ceae3..593264c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -215,10 +215,9 @@ static inline int dentry_string_cmp(const unsigned char *cs, const unsigned char

static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *ct, unsigned tcount)
{
- const unsigned char *cs;
/*
* Be careful about RCU walk racing with rename:
- * use ACCESS_ONCE to fetch the name pointer.
+ * use 'lockless_dereference' to fetch the name pointer.
*
* NOTE! Even if a rename will mean that the length
* was not loaded atomically, we don't care. The
@@ -232,8 +231,8 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c
* early because the data cannot match (there can
* be no NUL in the ct/tcount data)
*/
- cs = ACCESS_ONCE(dentry->d_name.name);
- smp_read_barrier_depends();
+ const unsigned char *cs = lockless_dereference(dentry->d_name.name);
+
return dentry_string_cmp(cs, ct, tcount);
}

--
1.8.5.2