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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * eCryptfs: Linux filesystem encryption layer4 *5 * Copyright (C) 1997-2003 Erez Zadok6 * Copyright (C) 2001-2003 Stony Brook University7 * Copyright (C) 2004-2006 International Business Machines Corp.8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>9 */10 11#include <linux/dcache.h>12#include <linux/namei.h>13#include <linux/mount.h>14#include <linux/fs_stack.h>15#include <linux/slab.h>16#include "ecryptfs_kernel.h"17 18/**19 * ecryptfs_d_revalidate - revalidate an ecryptfs dentry20 * @dentry: The ecryptfs dentry21 * @flags: lookup flags22 *23 * Called when the VFS needs to revalidate a dentry. This24 * is called whenever a name lookup finds a dentry in the25 * dcache. Most filesystems leave this as NULL, because all their26 * dentries in the dcache are valid.27 *28 * Returns 1 if valid, 0 otherwise.29 *30 */31static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)32{33 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);34 int rc = 1;35 36 if (flags & LOOKUP_RCU)37 return -ECHILD;38 39 if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE)40 rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);41 42 if (d_really_is_positive(dentry)) {43 struct inode *inode = d_inode(dentry);44 45 fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));46 if (!inode->i_nlink)47 return 0;48 }49 return rc;50}51 52struct kmem_cache *ecryptfs_dentry_info_cache;53 54static void ecryptfs_dentry_free_rcu(struct rcu_head *head)55{56 kmem_cache_free(ecryptfs_dentry_info_cache,57 container_of(head, struct ecryptfs_dentry_info, rcu));58}59 60/**61 * ecryptfs_d_release62 * @dentry: The ecryptfs dentry63 *64 * Called when a dentry is really deallocated.65 */66static void ecryptfs_d_release(struct dentry *dentry)67{68 struct ecryptfs_dentry_info *p = dentry->d_fsdata;69 if (p) {70 path_put(&p->lower_path);71 call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);72 }73}74 75const struct dentry_operations ecryptfs_dops = {76 .d_revalidate = ecryptfs_d_revalidate,77 .d_release = ecryptfs_d_release,78};79