Commit ae0a843c authored by He Kuang's avatar He Kuang Committed by Al Viro
Browse files

dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends() 



lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends().

Signed-off-by: default avatarHe Kuang <hekuang@huawei.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c074cefc

fs/dcache.c

+3 −4
Original line number Diff line number Diff line
@@ -226,10 +226,9 @@ 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
@@ -243,8 +242,8 @@ 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);

}