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>

2 files changed, 3 insertions, 3 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5e5c7ec1fc98..f91b35db4c6e 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -441,7 +441,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
         struct qstr lower_name;
         int rc = 0;
 
-        ecryptfs_dentry->d_op = &ecryptfs_dops;
+        d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
         if ((ecryptfs_dentry->d_name.len == 1
              && !strcmp(ecryptfs_dentry->d_name.name, "."))
             || (ecryptfs_dentry->d_name.len == 2
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index a9dbd62518e6..351038675376 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -189,7 +189,7 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
         if (special_file(lower_inode->i_mode))
                 init_special_inode(inode, lower_inode->i_mode,
                                    lower_inode->i_rdev);
-        dentry->d_op = &ecryptfs_dops;
+        d_set_d_op(dentry, &ecryptfs_dops);
         fsstack_copy_attr_all(inode, lower_inode);
         /* This size will be overwritten for real files w/ headers and
          * other metadata */
@@ -594,7 +594,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
                 deactivate_locked_super(s);
                 goto out;
         }
-        s->s_root->d_op = &ecryptfs_dops;
+        d_set_d_op(s->s_root, &ecryptfs_dops);
         s->s_root->d_sb = s;
         s->s_root->d_parent = s->s_root;