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, 5 insertions, 5 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index eb77471b8823..37e0a8bb077e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -438,7 +438,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
         if (dentry == NULL)
                 return;
 
-        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+        d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
         inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
         if (IS_ERR(inode))
                 goto out;
@@ -1188,7 +1188,7 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
         if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
                 goto out;
 
-        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+        d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
 
         /*
          * If we're doing an exclusive create, optimize away the lookup
@@ -1333,7 +1333,7 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry
                 res = ERR_PTR(-ENAMETOOLONG);
                 goto out;
         }
-        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
+        d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops);
 
         /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
          * the dentry. */
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index b3e36c3430de..c3a5a1126833 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -121,7 +121,7 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
         security_d_instantiate(ret, inode);
 
         if (ret->d_op == NULL)
-                ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+                d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
 out:
         nfs_free_fattr(fsinfo.fattr);
         return ret;
@@ -228,7 +228,7 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
         security_d_instantiate(ret, inode);
 
         if (ret->d_op == NULL)
-                ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+                d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops);
 
 out:
         nfs_free_fattr(fattr);