eCryptfs: Handle NULL nameidata pointers
Tyler Hicks [Thu, 17 Feb 2011 23:35:20 +0000 (17:35 -0600)]
Allow for NULL nameidata pointers in eCryptfs create, lookup, and
d_revalidate functions.

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

fs/ecryptfs/dentry.c
fs/ecryptfs/ecryptfs_kernel.h
fs/ecryptfs/inode.c

index 6fc4f31..534c1d4 100644 (file)
@@ -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);
index dbc84ed..e007534 100644 (file)
@@ -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,
index fc44823..eb0d267 100644 (file)
@@ -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);