[PATCH 8/12: eCryptfs] Dentry operations

Phillip Hellewell
2005-11-03T03:52:51Z

eCryptfs dentry operations.

Signed off by: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed off by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed off by: Michael Thompson <mmcthomps@us.ibm.com>
Signed off by: Kent Yoder <yoder1@us.ibm.com>

dentry.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 110 insertions(+)
--- linux-2.6.14-rc5-mm1/fs/ecryptfs/dentry.c 1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.14-rc5-mm1-ecryptfs/fs/ecryptfs/dentry.c 2005-11-01 14:40:09.000000000 -0600
@@ -0,0 +1,110 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (c) 1997-2003 Erez Zadok
+ * Copyright (c) 2001-2003 Stony Brook University
+ * Copyright (c) 2005 International Business Machines Corp.
+ * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif /* HAVE_CONFIG_H */
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * called when the VFS needs to revalidate a dentry. This
+ * is called whenever a name lookup finds a dentry in the
+ * dcache. Most filesystems leave this as NULL, because all their
+ * dentries in the dcache are valid.
+ *
+ *
+ * @param dentry ecryptfs dentry
+ * @param nd
+ * @return 1 if valid, 0 otherwise
+ */
+static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ int err = 1;
+ struct dentry *lower_dentry;
+ struct dentry *saved_dentry;
+ struct vfsmount *saved_vfsmount;
+ ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name.name = [%s]\n",
+ dentry->d_name.name);
+ lower_dentry = ecryptfs_lower_dentry(dentry);
+ if (!lower_dentry) {
+ err = 0;
+ goto out;
+ }
+ if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
+ goto out;
+ /* Call the lower dentry's d_revalidate (assuming it has one) */
+ saved_dentry = nd->dentry;
+ saved_vfsmount = nd->mnt;
+ nd->dentry = lower_dentry;
+ nd->mnt = SUPERBLOCK_TO_PRIVATE(dentry->d_sb)->lower_mnt;
+ err = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
+ nd->dentry = saved_dentry;
+ nd->mnt = saved_vfsmount;
+out:
+ ecryptfs_printk(1, KERN_NOTICE, "Exit; err = [%d]\n", err);
+ return err;
+}
+
+kmem_cache_t *ecryptfs_dentry_info_cache;
+
+/* Notes:
+ * Called when a dentry is really deallocated
+ * Sanity check? wrapper around ecryptfs_dput()
+ */
+static void ecryptfs_d_release(struct dentry *dentry)
+{
+ struct dentry *lower_dentry;
+ ecryptfs_printk(1, KERN_NOTICE, "Enter; dentry->d_name->name = [%s]\n",
+ dentry->d_name.name);
+ if (!dentry) {
+ ecryptfs_printk(0, KERN_ERR, "NULL dentry\n");
+ goto out;
+ }
+ if (!DENTRY_TO_PRIVATE(dentry)) {
+ ecryptfs_printk(1, KERN_ERR, "dentry without private data: "
+ "[%*s]\n", dentry->d_name.len,
+ dentry->d_name.name);
+ goto out;
+ }
+ lower_dentry = DENTRY_TO_LOWER(dentry);
+ /* TODO: Why do we look for an inode here? We should be
+ * freeing regardless */
+ /* OLD: if (lower_dentry && lower_dentry->d_inode) { */
+ if (DENTRY_TO_PRIVATE(dentry)) {
+ ecryptfs_kmem_cache_free(ecryptfs_dentry_info_cache,
+ DENTRY_TO_PRIVATE(dentry));
+ }
+ if (lower_dentry)
+ ecryptfs_dput(lower_dentry);
+out:
+ ecryptfs_printk(1, KERN_NOTICE, "Exit\n");
+ return;
+}
+
+struct dentry_operations ecryptfs_dops = {
+ .d_revalidate = ecryptfs_d_revalidate,
+ .d_release = ecryptfs_d_release,
+};