eCryptfs: Handle NULL nameidata pointers

Allow for NULL nameidata pointers in eCryptfs create, lookup, and
d_revalidate functions.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

3 files changed, 29 insertions, 26 deletions

diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index 6fc4f319b550..534c1d46e69e 100644
--- a/fs/ecryptfs/dentry.c
+++ b/fs/ecryptfs/dentry.c
@@ -46,24 +46,28 @@ static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
         struct dentry *lower_dentry;
         struct vfsmount *lower_mnt;
-        struct dentry *dentry_save;
-        struct vfsmount *vfsmount_save;
+        struct dentry *dentry_save = NULL;
+        struct vfsmount *vfsmount_save = NULL;
         int rc = 1;
 
-        if (nd->flags & LOOKUP_RCU)
+        if (nd && nd->flags & LOOKUP_RCU)
                 return -ECHILD;
 
         lower_dentry = ecryptfs_dentry_to_lower(dentry);
         lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
         if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
                 goto out;
-        dentry_save = nd->path.dentry;
-        vfsmount_save = nd->path.mnt;
-        nd->path.dentry = lower_dentry;
-        nd->path.mnt = lower_mnt;
+        if (nd) {
+                dentry_save = nd->path.dentry;
+                vfsmount_save = nd->path.mnt;
+                nd->path.dentry = lower_dentry;
+                nd->path.mnt = lower_mnt;
+        }
         rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
-        nd->path.dentry = dentry_save;
-        nd->path.mnt = vfsmount_save;
+        if (nd) {
+                nd->path.dentry = dentry_save;
+                nd->path.mnt = vfsmount_save;
+        }
         if (dentry->d_inode) {
                 struct inode *lower_inode =
                         ecryptfs_inode_to_lower(dentry->d_inode);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index dbc84ed96336..e00753496e3e 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -632,8 +632,7 @@ int ecryptfs_interpose(struct dentry *hidden_dentry,
                        u32 flags);
 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
                                         struct dentry *lower_dentry,
-                                        struct inode *ecryptfs_dir_inode,
-                                        struct nameidata *ecryptfs_nd);
+                                        struct inode *ecryptfs_dir_inode);
 int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
                                          size_t *decrypted_name_size,
                                          struct dentry *ecryptfs_dentry,
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index fc44823fea3a..eb0d267ee715 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -74,16 +74,20 @@ ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
         unsigned int flags_save;
         int rc;
 
-        dentry_save = nd->path.dentry;
-        vfsmount_save = nd->path.mnt;
-        flags_save = nd->flags;
-        nd->path.dentry = lower_dentry;
-        nd->path.mnt = lower_mnt;
-        nd->flags &= ~LOOKUP_OPEN;
+        if (nd) {
+                dentry_save = nd->path.dentry;
+                vfsmount_save = nd->path.mnt;
+                flags_save = nd->flags;
+                nd->path.dentry = lower_dentry;
+                nd->path.mnt = lower_mnt;
+                nd->flags &= ~LOOKUP_OPEN;
+        }
         rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
-        nd->path.dentry = dentry_save;
-        nd->path.mnt = vfsmount_save;
-        nd->flags = flags_save;
+        if (nd) {
+                nd->path.dentry = dentry_save;
+                nd->path.mnt = vfsmount_save;
+                nd->flags = flags_save;
+        }
         return rc;
 }
 
@@ -241,8 +245,7 @@ out:
  */
 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
                                         struct dentry *lower_dentry,
-                                        struct inode *ecryptfs_dir_inode,
-                                        struct nameidata *ecryptfs_nd)
+                                        struct inode *ecryptfs_dir_inode)
 {
         struct dentry *lower_dir_dentry;
         struct vfsmount *lower_mnt;
@@ -290,8 +293,6 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
                 goto out;
         if (special_file(lower_inode->i_mode))
                 goto out;
-        if (!ecryptfs_nd)
-                goto out;
         /* Released in this function */
         page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
         if (!page_virt) {
@@ -417,8 +418,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
         }
 lookup_and_interpose:
         rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
-                                                 ecryptfs_dir_inode,
-                                                 ecryptfs_nd);
+                                                 ecryptfs_dir_inode);
         goto out;
 out_d_drop:
         d_drop(ecryptfs_dentry);