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>

63 files changed, 174 insertions, 137 deletions

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index d39d8a53b579..5a24f40bb48e 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2233,7 +2233,7 @@ pfm_alloc_file(pfm_context_t *ctx)
         }
         path.mnt = mntget(pfmfs_mnt);
 
-        path.dentry->d_op = &pfmfs_dentry_operations;
+        d_set_d_op(path.dentry, &pfmfs_dentry_operations);
         d_add(path.dentry, inode);
 
         file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
diff --git a/drivers/staging/autofs/root.c b/drivers/staging/autofs/root.c
index 0fdec4befd84..b09adb57971f 100644
--- a/drivers/staging/autofs/root.c
+++ b/drivers/staging/autofs/root.c
@@ -237,7 +237,7 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr
          *
          * We need to do this before we release the directory semaphore.
          */
-        dentry->d_op = &autofs_dentry_operations;
+        d_set_d_op(dentry, &autofs_dentry_operations);
         dentry->d_flags |= DCACHE_AUTOFS_PENDING;
         d_add(dentry, NULL);
 
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index 5f79799d5d4a..78f09412740c 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -398,9 +398,9 @@ smb_new_dentry(struct dentry *dentry)
         struct smb_sb_info *server = server_from_dentry(dentry);
 
         if (server->mnt->flags & SMB_MOUNT_CASE)
-                dentry->d_op = &smbfs_dentry_operations_case;
+                d_set_d_op(dentry, &smbfs_dentry_operations_case);
         else
-                dentry->d_op = &smbfs_dentry_operations;
+                d_set_d_op(dentry, &smbfs_dentry_operations);
         dentry->d_time = jiffies;
 }
 
@@ -462,9 +462,9 @@ smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
         add_entry:
                         server = server_from_dentry(dentry);
                         if (server->mnt->flags & SMB_MOUNT_CASE)
-                                dentry->d_op = &smbfs_dentry_operations_case;
+                                d_set_d_op(dentry, &smbfs_dentry_operations_case);
                         else
-                                dentry->d_op = &smbfs_dentry_operations;
+                                d_set_d_op(dentry, &smbfs_dentry_operations);
 
                         d_add(dentry, inode);
                         smb_renew_times(dentry);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index f6f9081e6d2c..df8bbb358d54 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -635,9 +635,9 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
         }
 
         if (v9ses->cache)
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
         else
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
 
         d_instantiate(dentry, inode);
         err = v9fs_fid_add(dentry, fid);
@@ -749,7 +749,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
                                 err);
                         goto error;
                 }
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
                 d_instantiate(dentry, inode);
                 err = v9fs_fid_add(dentry, fid);
                 if (err < 0)
@@ -767,7 +767,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
                         err = PTR_ERR(inode);
                         goto error;
                 }
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
                 d_instantiate(dentry, inode);
         }
         /* Now set the ACL based on the default value */
@@ -956,7 +956,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
                                 err);
                         goto error;
                 }
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
                 d_instantiate(dentry, inode);
                 err = v9fs_fid_add(dentry, fid);
                 if (err < 0)
@@ -973,7 +973,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
                         err = PTR_ERR(inode);
                         goto error;
                 }
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
                 d_instantiate(dentry, inode);
         }
         /* Now set the ACL based on the default value */
@@ -1041,9 +1041,9 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 
 inst_out:
         if (v9ses->cache)
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
         else
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
 
         d_add(dentry, inode);
         return NULL;
@@ -1709,7 +1709,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
                                         err);
                         goto error;
                 }
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
                 d_instantiate(dentry, inode);
                 err = v9fs_fid_add(dentry, fid);
                 if (err < 0)
@@ -1722,7 +1722,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
                         err = PTR_ERR(inode);
                         goto error;
                 }
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
                 d_instantiate(dentry, inode);
         }
 
@@ -1856,7 +1856,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
                 ihold(old_dentry->d_inode);
         }
 
-        dentry->d_op = old_dentry->d_op;
+        d_set_d_op(dentry, old_dentry->d_op);
         d_instantiate(dentry, old_dentry->d_inode);
 
         return err;
@@ -1980,7 +1980,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode,
                                 err);
                         goto error;
                 }
-                dentry->d_op = &v9fs_cached_dentry_operations;
+                d_set_d_op(dentry, &v9fs_cached_dentry_operations);
                 d_instantiate(dentry, inode);
                 err = v9fs_fid_add(dentry, fid);
                 if (err < 0)
@@ -1996,7 +1996,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode,
                         err = PTR_ERR(inode);
                         goto error;
                 }
-                dentry->d_op = &v9fs_dentry_operations;
+                d_set_d_op(dentry, &v9fs_dentry_operations);
                 d_instantiate(dentry, inode);
         }
         /* Now set the ACL based on the default value */
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index a11e5e102716..bf7693c384f9 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -276,7 +276,7 @@ adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
         struct object_info obj;
         int error;
 
-        dentry->d_op = &adfs_dentry_operations; 
+        d_set_d_op(dentry, &adfs_dentry_operations);
         lock_kernel();
         error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
         if (error == 0) {
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 47dffc513a26..a4041b52fbca 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -484,7 +484,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
                 adfs_error(sb, "get root inode failed\n");
                 goto error;
         } else
-                sb->s_root->d_op = &adfs_dentry_operations;
+                d_set_d_op(sb->s_root, &adfs_dentry_operations);
         unlock_kernel();
         return 0;
 
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 5aca08c21100..944a4042fb65 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -240,7 +240,7 @@ affs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
                 if (IS_ERR(inode))
                         return ERR_CAST(inode);
         }
-        dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
+        d_set_d_op(dentry, AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations);
         d_add(dentry, inode);
         return NULL;
 }
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 4c18fcfb0a19..d39081bbe7ce 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -482,7 +482,7 @@ got_root:
                 printk(KERN_ERR "AFFS: Get root inode failed\n");
                 goto out_error;
         }
-        sb->s_root->d_op = &affs_dentry_operations;
+        d_set_d_op(sb->s_root, &affs_dentry_operations);
 
         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
         return 0;
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 2c18cde27000..b8bb7e7148d0 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -581,7 +581,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
         }
 
 success:
-        dentry->d_op = &afs_fs_dentry_operations;
+        d_set_d_op(dentry, &afs_fs_dentry_operations);
 
         d_add(dentry, inode);
         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 57ce55b2564c..aca8806fa206 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -113,7 +113,7 @@ struct file *anon_inode_getfile(const char *name,
          */
         ihold(anon_inode_inode);
 
-        path.dentry->d_op = &anon_inodefs_dentry_operations;
+        d_set_d_op(path.dentry, &anon_inodefs_dentry_operations);
         d_instantiate(path.dentry, anon_inode_inode);
 
         error = -ENFILE;
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index ac87e49fa706..a7bdb9dcac84 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -309,7 +309,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
                 goto fail_iput;
         pipe = NULL;
 
-        root->d_op = &autofs4_sb_dentry_operations;
+        d_set_d_op(root, &autofs4_sb_dentry_operations);
         root->d_fsdata = ino;
 
         /* Can this call block? */
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 10ca68a96dc7..bfe3f2eb684d 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -571,7 +571,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
                  * we check for the hashed dentry and return the newly
                  * hashed dentry.
                  */
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
 
                 /*
                  * And we need to ensure that the same dentry is used for
@@ -710,9 +710,9 @@ static int autofs4_dir_symlink(struct inode *dir,
         d_add(dentry, inode);
 
         if (dir == dir->i_sb->s_root->d_inode)
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
         else
-                dentry->d_op = &autofs4_dentry_operations;
+                d_set_d_op(dentry, &autofs4_dentry_operations);
 
         dentry->d_fsdata = ino;
         ino->dentry = dget(dentry);
@@ -845,9 +845,9 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         d_add(dentry, inode);
 
         if (dir == dir->i_sb->s_root->d_inode)
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
         else
-                dentry->d_op = &autofs4_dentry_operations;
+                d_set_d_op(dentry, &autofs4_dentry_operations);
 
         dentry->d_fsdata = ino;
         ino->dentry = dget(dentry);
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 659f532d26a0..0ccf9a8afcdf 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -110,7 +110,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 
         dentry = d_obtain_alias(inode);
         if (!IS_ERR(dentry))
-                dentry->d_op = &btrfs_dentry_operations;
+                d_set_d_op(dentry, &btrfs_dentry_operations);
         return dentry;
 fail:
         srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -225,7 +225,7 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
         key.offset = 0;
         dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
         if (!IS_ERR(dentry))
-                dentry->d_op = &btrfs_dentry_operations;
+                d_set_d_op(dentry, &btrfs_dentry_operations);
         return dentry;
 fail:
         btrfs_free_path(path);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f9d2994a42a2..63e4546b478a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4084,7 +4084,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
         int index;
         int ret;
 
-        dentry->d_op = &btrfs_dentry_operations;
+        d_set_d_op(dentry, &btrfs_dentry_operations);
 
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 58abc3da6111..cc01cf826769 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -42,11 +42,11 @@ int ceph_init_dentry(struct dentry *dentry)
 
         if (dentry->d_parent == NULL ||   /* nfs fh_to_dentry */
             ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
-                dentry->d_op = &ceph_dentry_ops;
+                d_set_d_op(dentry, &ceph_dentry_ops);
         else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
-                dentry->d_op = &ceph_snapdir_dentry_ops;
+                d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
         else
-                dentry->d_op = &ceph_snap_dentry_ops;
+                d_set_d_op(dentry, &ceph_snap_dentry_ops);
 
         di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
         if (!di)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 88bfe686ac00..e3b10ca6d453 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -135,9 +135,9 @@ static void setup_cifs_dentry(struct cifsTconInfo *tcon,
                               struct inode *newinode)
 {
         if (tcon->nocase)
-                direntry->d_op = &cifs_ci_dentry_ops;
+                d_set_d_op(direntry, &cifs_ci_dentry_ops);
         else
-                direntry->d_op = &cifs_dentry_ops;
+                d_set_d_op(direntry, &cifs_dentry_ops);
         d_instantiate(direntry, newinode);
 }
 
@@ -421,9 +421,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
                 rc = cifs_get_inode_info_unix(&newinode, full_path,
                                                 inode->i_sb, xid);
                 if (pTcon->nocase)
-                        direntry->d_op = &cifs_ci_dentry_ops;
+                        d_set_d_op(direntry, &cifs_ci_dentry_ops);
                 else
-                        direntry->d_op = &cifs_dentry_ops;
+                        d_set_d_op(direntry, &cifs_dentry_ops);
 
                 if (rc == 0)
                         d_instantiate(direntry, newinode);
@@ -604,9 +604,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 
         if ((rc == 0) && (newInode != NULL)) {
                 if (pTcon->nocase)
-                        direntry->d_op = &cifs_ci_dentry_ops;
+                        d_set_d_op(direntry, &cifs_ci_dentry_ops);
                 else
-                        direntry->d_op = &cifs_dentry_ops;
+                        d_set_d_op(direntry, &cifs_dentry_ops);
                 d_add(direntry, newInode);
                 if (posix_open) {
                         filp = lookup_instantiate_filp(nd, direntry,
@@ -634,9 +634,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                 rc = 0;
                 direntry->d_time = jiffies;
                 if (pTcon->nocase)
-                        direntry->d_op = &cifs_ci_dentry_ops;
+                        d_set_d_op(direntry, &cifs_ci_dentry_ops);
                 else
-                        direntry->d_op = &cifs_dentry_ops;
+                        d_set_d_op(direntry, &cifs_dentry_ops);
                 d_add(direntry, NULL);
         /*      if it was once a directory (but how can we tell?) we could do
                 shrink_dcache_parent(direntry); */
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 99b9a2cc14b7..2a239d878e85 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1319,9 +1319,9 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
         to set uid/gid */
                         inc_nlink(inode);
                         if (pTcon->nocase)
-                                direntry->d_op = &cifs_ci_dentry_ops;
+                                d_set_d_op(direntry, &cifs_ci_dentry_ops);
                         else
-                                direntry->d_op = &cifs_dentry_ops;
+                                d_set_d_op(direntry, &cifs_dentry_ops);
 
                         cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
                         cifs_fill_uniqueid(inode->i_sb, &fattr);
@@ -1363,9 +1363,9 @@ mkdir_get_info:
                                                  inode->i_sb, xid, NULL);
 
                 if (pTcon->nocase)
-                        direntry->d_op = &cifs_ci_dentry_ops;
+                        d_set_d_op(direntry, &cifs_ci_dentry_ops);
                 else
-                        direntry->d_op = &cifs_dentry_ops;
+                        d_set_d_op(direntry, &cifs_dentry_ops);
                 d_instantiate(direntry, newinode);
                  /* setting nlink not necessary except in cases where we
                   * failed to get it from the server or was set bogus */
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 85cdbf831e7b..fe2f6a93c49e 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -525,9 +525,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
                               rc);
                 } else {
                         if (pTcon->nocase)
-                                direntry->d_op = &cifs_ci_dentry_ops;
+                                d_set_d_op(direntry, &cifs_ci_dentry_ops);
                         else
-                                direntry->d_op = &cifs_dentry_ops;
+                                d_set_d_op(direntry, &cifs_dentry_ops);
                         d_instantiate(direntry, newinode);
                 }
         }
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index ee463aeca0b0..ec5b68e3b928 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -103,9 +103,9 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
         }
 
         if (cifs_sb_master_tcon(CIFS_SB(sb))->nocase)
-                dentry->d_op = &cifs_ci_dentry_ops;
+                d_set_d_op(dentry, &cifs_ci_dentry_ops);
         else
-                dentry->d_op = &cifs_dentry_ops;
+                d_set_d_op(dentry, &cifs_dentry_ops);
 
         alias = d_materialise_unique(dentry, inode);
         if (alias != NULL) {
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 9e37e8bc9b89..aa40c811f8d2 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -125,7 +125,7 @@ static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struc
                 return ERR_PTR(error);
 
 exit:
-        entry->d_op = &coda_dentry_operations;
+        d_set_d_op(entry, &coda_dentry_operations);
 
         if (inode && (type & CODA_NOCACHE))
                 coda_flag_inode(inode, C_VATTR | C_PURGE);
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,
diff --git a/fs/dcache.c b/fs/dcache.c
index 1d5cf511e1c7..f9693da3efbd 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -398,7 +398,7 @@ repeat:
                 return;
         }
 
-        if (dentry->d_op && dentry->d_op->d_delete) {
+        if (dentry->d_flags & DCACHE_OP_DELETE) {
                 if (dentry->d_op->d_delete(dentry))
                         goto kill_it;
         }
@@ -1301,6 +1301,28 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name)
 }
 EXPORT_SYMBOL(d_alloc_name);
 
+void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
+{
+        BUG_ON(dentry->d_op);
+        BUG_ON(dentry->d_flags & (DCACHE_OP_HASH        |
+                                DCACHE_OP_COMPARE       |
+                                DCACHE_OP_REVALIDATE    |
+                                DCACHE_OP_DELETE ));
+        dentry->d_op = op;
+        if (!op)
+                return;
+        if (op->d_hash)
+                dentry->d_flags |= DCACHE_OP_HASH;
+        if (op->d_compare)
+                dentry->d_flags |= DCACHE_OP_COMPARE;
+        if (op->d_revalidate)
+                dentry->d_flags |= DCACHE_OP_REVALIDATE;
+        if (op->d_delete)
+                dentry->d_flags |= DCACHE_OP_DELETE;
+
+}
+EXPORT_SYMBOL(d_set_d_op);
+
 static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 {
         spin_lock(&dentry->d_lock);
@@ -1731,7 +1753,7 @@ seqretry:
                  */
                 if (read_seqcount_retry(&dentry->d_seq, *seq))
                         goto seqretry;
-                if (parent->d_op && parent->d_op->d_compare) {
+                if (parent->d_flags & DCACHE_OP_COMPARE) {
                         if (parent->d_op->d_compare(parent, *inode,
                                                 dentry, i,
                                                 tlen, tname, name))
@@ -1846,7 +1868,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
                  */
                 tlen = dentry->d_name.len;
                 tname = dentry->d_name.name;
-                if (parent->d_op && parent->d_op->d_compare) {
+                if (parent->d_flags & DCACHE_OP_COMPARE) {
                         if (parent->d_op->d_compare(parent, parent->d_inode,
                                                 dentry, dentry->d_inode,
                                                 tlen, tname, name))
@@ -1887,7 +1909,7 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
          * routine may choose to leave the hash value unchanged.
          */
         name->hash = full_name_hash(name->name, name->len);
-        if (dir->d_op && dir->d_op->d_hash) {
+        if (dir->d_flags & DCACHE_OP_HASH) {
                 if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
                         goto out;
         }
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;
 
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 8cccfebee180..206351af7c58 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -750,7 +750,7 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
          */
         result = d_obtain_alias(inode);
         if (!IS_ERR(result))
-                result->d_op = sb->s_root->d_op;
+                d_set_d_op(result, sb->s_root->d_op);
         return result;
 }
 
@@ -800,7 +800,7 @@ static struct dentry *fat_get_parent(struct dentry *child)
 
         parent = d_obtain_alias(inode);
         if (!IS_ERR(parent))
-                parent->d_op = sb->s_root->d_op;
+                d_set_d_op(parent, sb->s_root->d_op);
 out:
         unlock_super(sb);
 
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 3b3e072d8982..35ffe43afa4b 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -227,10 +227,10 @@ static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
         }
 out:
         unlock_super(sb);
-        dentry->d_op = &msdos_dentry_operations;
+        d_set_d_op(dentry, &msdos_dentry_operations);
         dentry = d_splice_alias(inode, dentry);
         if (dentry)
-                dentry->d_op = &msdos_dentry_operations;
+                d_set_d_op(dentry, &msdos_dentry_operations);
         return dentry;
 
 error:
@@ -673,7 +673,7 @@ static int msdos_fill_super(struct super_block *sb, void *data, int silent)
         }
 
         sb->s_flags |= MS_NOATIME;
-        sb->s_root->d_op = &msdos_dentry_operations;
+        d_set_d_op(sb->s_root, &msdos_dentry_operations);
         unlock_super(sb);
         return 0;
 }
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 4fc06278db48..3be5ed7d859f 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -766,11 +766,11 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
 
 out:
         unlock_super(sb);
-        dentry->d_op = sb->s_root->d_op;
+        d_set_d_op(dentry, sb->s_root->d_op);
         dentry->d_time = dentry->d_parent->d_inode->i_version;
         dentry = d_splice_alias(inode, dentry);
         if (dentry) {
-                dentry->d_op = sb->s_root->d_op;
+                d_set_d_op(dentry, sb->s_root->d_op);
                 dentry->d_time = dentry->d_parent->d_inode->i_version;
         }
         return dentry;
@@ -1072,9 +1072,9 @@ static int vfat_fill_super(struct super_block *sb, void *data, int silent)
         }
 
         if (MSDOS_SB(sb)->options.name_check != 's')
-                sb->s_root->d_op = &vfat_ci_dentry_ops;
+                d_set_d_op(sb->s_root, &vfat_ci_dentry_ops);
         else
-                sb->s_root->d_op = &vfat_dentry_ops;
+                d_set_d_op(sb->s_root, &vfat_dentry_ops);
 
         unlock_super(sb);
         return 0;
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c9627c95482d..c9a8a426a395 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -347,7 +347,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
         }
 
         entry = newent ? newent : entry;
-        entry->d_op = &fuse_dentry_operations;
+        d_set_d_op(entry, &fuse_dentry_operations);
         if (outarg_valid)
                 fuse_change_entry_timeout(entry, &outarg);
         else
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 44e0a6c57e87..a8b31da19b93 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -626,7 +626,7 @@ static struct dentry *fuse_get_dentry(struct super_block *sb,
 
         entry = d_obtain_alias(inode);
         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
-                entry->d_op = &fuse_dentry_operations;
+                d_set_d_op(entry, &fuse_dentry_operations);
                 fuse_invalidate_entry_cache(entry);
         }
 
@@ -728,7 +728,7 @@ static struct dentry *fuse_get_parent(struct dentry *child)
 
         parent = d_obtain_alias(inode);
         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
-                parent->d_op = &fuse_dentry_operations;
+                d_set_d_op(parent, &fuse_dentry_operations);
                 fuse_invalidate_entry_cache(parent);
         }
 
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
index 5ab3839dfcb9..97012ecff560 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -130,7 +130,7 @@ static struct dentry *gfs2_get_parent(struct dentry *child)
 
         dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
         if (!IS_ERR(dentry))
-                dentry->d_op = &gfs2_dops;
+                d_set_d_op(dentry, &gfs2_dops);
         return dentry;
 }
 
@@ -158,7 +158,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
 out_inode:
         dentry = d_obtain_alias(inode);
         if (!IS_ERR(dentry))
-                dentry->d_op = &gfs2_dops;
+                d_set_d_op(dentry, &gfs2_dops);
         return dentry;
 }
 
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 3eb1393f7b81..2aeabd4218cc 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -440,7 +440,7 @@ static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
                 iput(inode);
                 return -ENOMEM;
         }
-        dentry->d_op = &gfs2_dops;
+        d_set_d_op(dentry, &gfs2_dops);
         *dptr = dentry;
         return 0;
 }
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 12cbea7502c2..f28f89796f4d 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -106,7 +106,7 @@ static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
 {
         struct inode *inode = NULL;
 
-        dentry->d_op = &gfs2_dops;
+        d_set_d_op(dentry, &gfs2_dops);
 
         inode = gfs2_lookupi(dir, &dentry->d_name, 0);
         if (inode && IS_ERR(inode))
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index 2b3b8611b41b..ea4aefe7c652 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -25,7 +25,7 @@ static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
         struct inode *inode = NULL;
         int res;
 
-        dentry->d_op = &hfs_dentry_operations;
+        d_set_d_op(dentry, &hfs_dentry_operations);
 
         hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
         hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index ef4ee5716abe..0bef62aa4f42 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -434,7 +434,7 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent)
         if (!sb->s_root)
                 goto bail_iput;
 
-        sb->s_root->d_op = &hfs_dentry_operations;
+        d_set_d_op(sb->s_root, &hfs_dentry_operations);
 
         /* everything's okay */
         return 0;
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 9d59c0571f59..ccab87145f7a 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -37,7 +37,7 @@ static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
 
         sb = dir->i_sb;
 
-        dentry->d_op = &hfsplus_dentry_operations;
+        d_set_d_op(dentry, &hfsplus_dentry_operations);
         dentry->d_fsdata = NULL;
         hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
         hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 182e83a9079e..ddf712e4700e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -419,7 +419,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
                 err = -ENOMEM;
                 goto cleanup;
         }
-        sb->s_root->d_op = &hfsplus_dentry_operations;
+        d_set_d_op(sb->s_root, &hfsplus_dentry_operations);
 
         str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
         str.name = HFSP_HIDDENDIR_NAME;
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 861113fcfc88..0bc81cf256b8 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -612,7 +612,7 @@ struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
                 goto out_put;
 
         d_add(dentry, inode);
-        dentry->d_op = &hostfs_dentry_ops;
+        d_set_d_op(dentry, &hostfs_dentry_ops);
         return NULL;
 
  out_put:
diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c
index 35526df1fd32..32c13a94e1e9 100644
--- a/fs/hpfs/dentry.c
+++ b/fs/hpfs/dentry.c
@@ -65,5 +65,5 @@ static const struct dentry_operations hpfs_dentry_operations = {
 
 void hpfs_set_dentry_operations(struct dentry *dentry)
 {
-        dentry->d_op = &hpfs_dentry_operations;
+        d_set_d_op(dentry, &hpfs_dentry_operations);
 }
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d8f3a652243d..844a7903c72f 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -949,7 +949,7 @@ root_found:
                 table += 2;
         if (opt.check == 'r')
                 table++;
-        s->s_root->d_op = &isofs_dentry_ops[table];
+        d_set_d_op(s->s_root, &isofs_dentry_ops[table]);
 
         kfree(opt.iocharset);
 
diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c
index 715f7d318046..679a849c3b27 100644
--- a/fs/isofs/namei.c
+++ b/fs/isofs/namei.c
@@ -172,7 +172,7 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam
         struct inode *inode;
         struct page *page;
 
-        dentry->d_op = dir->i_sb->s_root->d_op;
+        d_set_d_op(dentry, dir->i_sb->s_root->d_op);
 
         page = alloc_page(GFP_USER);
         if (!page)
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 57f90dad8919..a151cbdec626 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1466,7 +1466,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
         jfs_info("jfs_lookup: name = %s", name);
 
         if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
-                dentry->d_op = &jfs_ci_dentry_operations;
+                d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
         if ((name[0] == '.') && (len == 1))
                 inum = dip->i_ino;
@@ -1495,7 +1495,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
         dentry = d_splice_alias(ip, dentry);
 
         if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
-                dentry->d_op = &jfs_ci_dentry_operations;
+                d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
         return dentry;
 }
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index b715b0f7bdfd..3150d766e0d4 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -525,7 +525,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
                 goto out_no_root;
 
         if (sbi->mntflag & JFS_OS2)
-                sb->s_root->d_op = &jfs_ci_dentry_operations;
+                d_set_d_op(sb->s_root, &jfs_ci_dentry_operations);
 
         /* logical blocks are represented by 40 bits in pxd_t, etc. */
         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
diff --git a/fs/libfs.c b/fs/libfs.c
index 28b36663c44e..889311e3d06b 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -59,7 +59,7 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct na
 
         if (dentry->d_name.len > NAME_MAX)
                 return ERR_PTR(-ENAMETOOLONG);
-        dentry->d_op = &simple_dentry_operations;
+        d_set_d_op(dentry, &simple_dentry_operations);
         d_add(dentry, NULL);
         return NULL;
 }
diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index c0d35a3accef..1b9e07728a9f 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -23,7 +23,7 @@ static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, st
         struct inode * inode = NULL;
         ino_t ino;
 
-        dentry->d_op = dir->i_sb->s_root->d_op;
+        d_set_d_op(dentry, dir->i_sb->s_root->d_op);
 
         if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
                 return ERR_PTR(-ENAMETOOLONG);
diff --git a/fs/namei.c b/fs/namei.c
index c731b50a6184..90bd2873e117 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -587,6 +587,17 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
         return dentry;
 }
 
+static inline int need_reval_dot(struct dentry *dentry)
+{
+        if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
+                return 0;
+
+        if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)))
+                return 0;
+
+        return 1;
+}
+
 /*
  * force_reval_path - force revalidation of a dentry
  *
@@ -610,10 +621,9 @@ force_reval_path(struct path *path, struct nameidata *nd)
 
         /*
          * only check on filesystems where it's possible for the dentry to
-         * become stale. It's assumed that if this flag is set then the
-         * d_revalidate op will also be defined.
+         * become stale.
          */
-        if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))
+        if (!need_reval_dot(dentry))
                 return 0;
 
         status = dentry->d_op->d_revalidate(dentry, nd);
@@ -1003,7 +1013,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
          * See if the low-level filesystem might want
          * to use its own hash..
          */
-        if (parent->d_op && parent->d_op->d_hash) {
+        if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
                 int err = parent->d_op->d_hash(parent, nd->inode, name);
                 if (err < 0)
                         return err;
@@ -1029,7 +1039,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
                         return -ECHILD;
 
                 nd->seq = seq;
-                if (dentry->d_op && dentry->d_op->d_revalidate) {
+                if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
                         /* We commonly drop rcu-walk here */
                         if (nameidata_dentry_drop_rcu(nd, dentry))
                                 return -ECHILD;
@@ -1043,7 +1053,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
                 if (!dentry)
                         goto need_lookup;
 found:
-                if (dentry->d_op && dentry->d_op->d_revalidate)
+                if (dentry->d_flags & DCACHE_OP_REVALIDATE)
                         goto need_revalidate;
 done:
                 path->mnt = mnt;
@@ -1281,8 +1291,7 @@ return_reval:
                  * We bypassed the ordinary revalidation routines.
                  * We may need to check the cached dentry for staleness.
                  */
-                if (nd->path.dentry && nd->path.dentry->d_sb &&
-                    (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) {
+                if (need_reval_dot(nd->path.dentry)) {
                         if (nameidata_drop_rcu_maybe(nd))
                                 return -ECHILD;
                         err = -ESTALE;
@@ -1602,7 +1611,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
          * See if the low-level filesystem might want
          * to use its own hash..
          */
-        if (base->d_op && base->d_op->d_hash) {
+        if (base->d_flags & DCACHE_OP_HASH) {
                 err = base->d_op->d_hash(base, inode, name);
                 dentry = ERR_PTR(err);
                 if (err < 0)
@@ -1616,7 +1625,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
          */
         dentry = d_lookup(base, name);
 
-        if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+        if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE))
                 dentry = do_revalidate(dentry, nd);
 
         if (!dentry)
@@ -2070,7 +2079,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                 follow_dotdot(nd);
                 dir = nd->path.dentry;
         case LAST_DOT:
-                if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
+                if (need_reval_dot(dir)) {
                         if (!dir->d_op->d_revalidate(dir, nd)) {
                                 error = -ESTALE;
                                 goto exit;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 0ba3cdc95a44..4b9cbb28d7fa 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -633,7 +633,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
                 entry->ino = iunique(dir->i_sb, 2);
                 inode = ncp_iget(dir->i_sb, entry);
                 if (inode) {
-                        newdent->d_op = &ncp_dentry_operations;
+                        d_set_d_op(newdent, &ncp_dentry_operations);
                         d_instantiate(newdent, inode);
                         if (!hashed)
                                 d_rehash(newdent);
@@ -889,7 +889,7 @@ static struct dentry *ncp_lookup(struct inode *dir, struct dentry *dentry, struc
         if (inode) {
                 ncp_new_dentry(dentry);
 add_entry:
-                dentry->d_op = &ncp_dentry_operations;
+                d_set_d_op(dentry, &ncp_dentry_operations);
                 d_add(dentry, inode);
                 error = 0;
         }
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 60047dbeb38d..0c75a5f3cafd 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -717,7 +717,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
         sb->s_root = d_alloc_root(root_inode);
         if (!sb->s_root)
                 goto out_no_root;
-        sb->s_root->d_op = &ncp_root_dentry_operations;
+        d_set_d_op(sb->s_root, &ncp_root_dentry_operations);
         return 0;
 
 out_no_root:
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);
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
index 19ad145d2af3..6adafa576065 100644
--- a/fs/ocfs2/export.c
+++ b/fs/ocfs2/export.c
@@ -138,7 +138,7 @@ check_gen:
 
         result = d_obtain_alias(inode);
         if (!IS_ERR(result))
-                result->d_op = &ocfs2_dentry_ops;
+                d_set_d_op(result, &ocfs2_dentry_ops);
         else
                 mlog_errno(PTR_ERR(result));
 
@@ -176,7 +176,7 @@ static struct dentry *ocfs2_get_parent(struct dentry *child)
 
         parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
         if (!IS_ERR(parent))
-                parent->d_op = &ocfs2_dentry_ops;
+                d_set_d_op(parent, &ocfs2_dentry_ops);
 
 bail_unlock:
         ocfs2_inode_unlock(dir, 0);
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index ff5744e1e36f..d14cad6e2e41 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -147,7 +147,7 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry,
         spin_unlock(&oi->ip_lock);
 
 bail_add:
-        dentry->d_op = &ocfs2_dentry_ops;
+        d_set_d_op(dentry, &ocfs2_dentry_ops);
         ret = d_splice_alias(inode, dentry);
 
         if (inode) {
@@ -415,7 +415,7 @@ static int ocfs2_mknod(struct inode *dir,
                 mlog_errno(status);
                 goto leave;
         }
-        dentry->d_op = &ocfs2_dentry_ops;
+        d_set_d_op(dentry, &ocfs2_dentry_ops);
 
         status = ocfs2_add_entry(handle, dentry, inode,
                                  OCFS2_I(inode)->ip_blkno, parent_fe_bh,
@@ -743,7 +743,7 @@ static int ocfs2_link(struct dentry *old_dentry,
         }
 
         ihold(inode);
-        dentry->d_op = &ocfs2_dentry_ops;
+        d_set_d_op(dentry, &ocfs2_dentry_ops);
         d_instantiate(dentry, inode);
 
 out_commit:
@@ -1794,7 +1794,7 @@ static int ocfs2_symlink(struct inode *dir,
                 mlog_errno(status);
                 goto bail;
         }
-        dentry->d_op = &ocfs2_dentry_ops;
+        d_set_d_op(dentry, &ocfs2_dentry_ops);
 
         status = ocfs2_add_entry(handle, dentry, inode,
                                  le64_to_cpu(fe->i_blkno), parent_fe_bh,
@@ -2459,7 +2459,7 @@ int ocfs2_mv_orphaned_inode_to_new(struct inode *dir,
                 goto out_commit;
         }
 
-        dentry->d_op = &ocfs2_dentry_ops;
+        d_set_d_op(dentry, &ocfs2_dentry_ops);
         d_instantiate(dentry, inode);
         status = 0;
 out_commit:
diff --git a/fs/pipe.c b/fs/pipe.c
index ae3592dcc88c..01a786567810 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1004,7 +1004,7 @@ struct file *create_write_pipe(int flags)
                 goto err_inode;
         path.mnt = mntget(pipe_mnt);
 
-        path.dentry->d_op = &pipefs_dentry_operations;
+        d_set_d_op(path.dentry, &pipefs_dentry_operations);
         d_instantiate(path.dentry, inode);
 
         err = -ENFILE;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d932fdb6a245..85f0a80912aa 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1969,7 +1969,7 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
         inode->i_op = &proc_pid_link_inode_operations;
         inode->i_size = 64;
         ei->op.proc_get_link = proc_fd_link;
-        dentry->d_op = &tid_fd_dentry_operations;
+        d_set_d_op(dentry, &tid_fd_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (tid_fd_revalidate(dentry, NULL))
@@ -2137,7 +2137,7 @@ static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
         ei->fd = fd;
         inode->i_mode = S_IFREG | S_IRUSR;
         inode->i_fop = &proc_fdinfo_file_operations;
-        dentry->d_op = &tid_fd_dentry_operations;
+        d_set_d_op(dentry, &tid_fd_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (tid_fd_revalidate(dentry, NULL))
@@ -2196,7 +2196,7 @@ static struct dentry *proc_pident_instantiate(struct inode *dir,
         if (p->fop)
                 inode->i_fop = p->fop;
         ei->op = p->op;
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (pid_revalidate(dentry, NULL))
@@ -2615,7 +2615,7 @@ static struct dentry *proc_base_instantiate(struct inode *dir,
         if (p->fop)
                 inode->i_fop = p->fop;
         ei->op = p->op;
-        dentry->d_op = &proc_base_dentry_operations;
+        d_set_d_op(dentry, &proc_base_dentry_operations);
         d_add(dentry, inode);
         error = NULL;
 out:
@@ -2926,7 +2926,7 @@ static struct dentry *proc_pid_instantiate(struct inode *dir,
         inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
                 ARRAY_SIZE(tgid_base_stuff));
 
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
 
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
@@ -3169,7 +3169,7 @@ static struct dentry *proc_task_instantiate(struct inode *dir,
         inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
                 ARRAY_SIZE(tid_base_stuff));
 
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
 
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 1d607be36d95..f766be29d2c7 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -439,7 +439,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
 out_unlock:
 
         if (inode) {
-                dentry->d_op = &proc_dentry_operations;
+                d_set_d_op(dentry, &proc_dentry_operations);
                 d_add(dentry, inode);
                 return NULL;
         }
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 998e3a715bcc..35efd85a4d32 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -120,7 +120,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
                 goto out;
 
         err = NULL;
-        dentry->d_op = &proc_sys_dentry_operations;
+        d_set_d_op(dentry, &proc_sys_dentry_operations);
         d_add(dentry, inode);
 
 out:
@@ -201,7 +201,7 @@ static int proc_sys_fill_cache(struct file *filp, void *dirent,
                                 dput(child);
                                 return -ENOMEM;
                         } else {
-                                child->d_op = &proc_sys_dentry_operations;
+                                d_set_d_op(child, &proc_sys_dentry_operations);
                                 d_add(child, inode);
                         }
                 } else {
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 5d04a7828e7a..e0f0d7ea10a1 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -990,7 +990,7 @@ int reiserfs_lookup_privroot(struct super_block *s)
                                 strlen(PRIVROOT_NAME));
         if (!IS_ERR(dentry)) {
                 REISERFS_SB(s)->priv_root = dentry;
-                dentry->d_op = &xattr_lookup_poison_ops;
+                d_set_d_op(dentry, &xattr_lookup_poison_ops);
                 if (dentry->d_inode)
                         dentry->d_inode->i_flags |= S_PRIVATE;
         } else
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 27e1102e303e..3e076caa8daf 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -701,7 +701,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
         /* instantiate and hash dentry */
         ret = d_find_alias(inode);
         if (!ret) {
-                dentry->d_op = &sysfs_dentry_ops;
+                d_set_d_op(dentry, &sysfs_dentry_ops);
                 dentry->d_fsdata = sysfs_get(sd);
                 d_add(dentry, inode);
         } else {
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index 7507aeb4c90e..b5e68da2db32 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -48,7 +48,7 @@ static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, st
         struct inode * inode = NULL;
         ino_t ino;
 
-        dentry->d_op = dir->i_sb->s_root->d_op;
+        d_set_d_op(dentry, dir->i_sb->s_root->d_op);
         if (dentry->d_name.len > SYSV_NAMELEN)
                 return ERR_PTR(-ENAMETOOLONG);
         ino = sysv_inode_by_name(dentry);
diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index 3d9c62be0c10..76712aefc4ab 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -346,7 +346,7 @@ static int complete_read_super(struct super_block *sb, int silent, int size)
         if (sbi->s_forced_ro)
                 sb->s_flags |= MS_RDONLY;
         if (sbi->s_truncate)
-                sb->s_root->d_op = &sysv_dentry_operations;
+                d_set_d_op(sb->s_root, &sysv_dentry_operations);
         return 1;
 }
 
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index e4414693065e..f4b40a751f09 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -183,6 +183,11 @@ struct dentry_operations {
 #define DCACHE_GENOCIDE         0x0200
 #define DCACHE_MOUNTED          0x0400  /* is a mountpoint */
 
+#define DCACHE_OP_HASH          0x1000
+#define DCACHE_OP_COMPARE       0x2000
+#define DCACHE_OP_REVALIDATE    0x4000
+#define DCACHE_OP_DELETE        0x8000
+
 
 extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
@@ -201,6 +206,7 @@ extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
 extern void __d_drop(struct dentry *dentry);
 extern void d_drop(struct dentry *dentry);
 extern void d_delete(struct dentry *);
+extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
 
 /* allocate/de-allocate */
 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
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;
 }
diff --git a/net/socket.c b/net/socket.c
index 817dc92e9ef8..991e266bc7ae 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -368,7 +368,7 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
         }
         path.mnt = mntget(sock_mnt);
 
-        path.dentry->d_op = &sockfs_dentry_operations;
+        d_set_d_op(path.dentry, &sockfs_dentry_operations);
         d_instantiate(path.dentry, SOCK_INODE(sock));
         SOCK_INODE(sock)->i_fop = &socket_file_ops;
 
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 2899fe27f880..09f01f41e55a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -591,7 +591,7 @@ static struct dentry *__rpc_lookup_create(struct dentry *parent,
                 }
         }
         if (!dentry->d_inode)
-                dentry->d_op = &rpc_dentry_operations;
+                d_set_d_op(dentry, &rpc_dentry_operations);
 out_err:
         return dentry;
 }