fs: dcache reduce branches in lookup path

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 9f41470c3949..51cddc11cd85 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2222,7 +2222,7 @@ static struct dentry *cgroup_lookup(struct inode *dir,
 
         if (dentry->d_name.len > NAME_MAX)
                 return ERR_PTR(-ENAMETOOLONG);
-        dentry->d_op = &cgroup_dentry_operations;
+        d_set_d_op(dentry, &cgroup_dentry_operations);
         d_add(dentry, NULL);
         return NULL;
 }