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-rw-r--r--fs/ecryptfs/dentry.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
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+++ b/fs/ecryptfs/dentry.c
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+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2003 Erez Zadok
+ * Copyright (C) 2001-2003 Stony Brook University
+ * Copyright (C) 2004-2006 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.
+ */
+
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/fs_stack.h>
+#include <linux/slab.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
+ * @dentry: The ecryptfs dentry
+ * @flags: lookup flags
+ *
+ * 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.
+ *
+ * Returns 1 if valid, 0 otherwise.
+ *
+ */
+static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ int rc = 1;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE)
+ rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
+
+ if (d_really_is_positive(dentry)) {
+ struct inode *inode = d_inode(dentry);
+
+ fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));
+ if (!inode->i_nlink)
+ return 0;
+ }
+ return rc;
+}
+
+struct kmem_cache *ecryptfs_dentry_info_cache;
+
+static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
+{
+ kmem_cache_free(ecryptfs_dentry_info_cache,
+ container_of(head, struct ecryptfs_dentry_info, rcu));
+}
+
+/**
+ * ecryptfs_d_release
+ * @dentry: The ecryptfs dentry
+ *
+ * Called when a dentry is really deallocated.
+ */
+static void ecryptfs_d_release(struct dentry *dentry)
+{
+ struct ecryptfs_dentry_info *p = dentry->d_fsdata;
+ if (p) {
+ path_put(&p->lower_path);
+ call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
+ }
+}
+
+const struct dentry_operations ecryptfs_dops = {
+ .d_revalidate = ecryptfs_d_revalidate,
+ .d_release = ecryptfs_d_release,
+};