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, 4 insertions, 4 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index e9acea440ffc..36637a8c1ed3 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -442,7 +442,7 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
                 return error;
         }
 
-        dentry->d_op = &configfs_dentry_ops;
+        d_set_d_op(dentry, &configfs_dentry_ops);
         d_rehash(dentry);
 
         return 0;
@@ -489,7 +489,7 @@ static struct dentry * configfs_lookup(struct inode *dir,
                  */
                 if (dentry->d_name.len > NAME_MAX)
                         return ERR_PTR(-ENAMETOOLONG);
-                dentry->d_op = &configfs_dentry_ops;
+                d_set_d_op(dentry, &configfs_dentry_ops);
                 d_add(dentry, NULL);
                 return NULL;
         }
@@ -683,7 +683,7 @@ static int create_default_group(struct config_group *parent_group,
         ret = -ENOMEM;
         child = d_alloc(parent, &name);
         if (child) {
-                child->d_op = &configfs_dentry_ops;
+                d_set_d_op(child, &configfs_dentry_ops);
                 d_add(child, NULL);
 
                 ret = configfs_attach_group(&parent_group->cg_item,
@@ -1681,7 +1681,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
         err = -ENOMEM;
         dentry = d_alloc(configfs_sb->s_root, &name);
         if (dentry) {
-                dentry->d_op = &configfs_dentry_ops;
+                d_set_d_op(dentry, &configfs_dentry_ops);
                 d_add(dentry, NULL);
 
                 err = configfs_attach_group(sd->s_element, &group->cg_item,