1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contians vfs dentry ops for the 9P2000 protocol.
4 *
5 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8
9#include <linux/module.h>
10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/file.h>
13#include <linux/pagemap.h>
14#include <linux/stat.h>
15#include <linux/string.h>
16#include <linux/namei.h>
17#include <linux/sched.h>
18#include <linux/slab.h>
19#include <net/9p/9p.h>
20#include <net/9p/client.h>
21
22#include "v9fs.h"
23#include "v9fs_vfs.h"
24#include "fid.h"
25
26/**
27 * v9fs_cached_dentry_delete - called when dentry refcount equals 0
28 * @dentry:  dentry in question
29 *
30 */
31static int v9fs_cached_dentry_delete(const struct dentry *dentry)
32{
33	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
34		 dentry, dentry);
35
36	/* Don't cache negative dentries */
37	if (d_really_is_negative(dentry))
38		return 1;
39	return 0;
40}
41
42/**
43 * v9fs_dentry_release - called when dentry is going to be freed
44 * @dentry:  dentry that is being release
45 *
46 */
47
48static void v9fs_dentry_release(struct dentry *dentry)
49{
50	struct hlist_node *p, *n;
51
52	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
53		 dentry, dentry);
54	hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
55		p9_fid_put(hlist_entry(p, struct p9_fid, dlist));
56	dentry->d_fsdata = NULL;
57}
58
59static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
60{
61	struct p9_fid *fid;
62	struct inode *inode;
63	struct v9fs_inode *v9inode;
64
65	if (flags & LOOKUP_RCU)
66		return -ECHILD;
67
68	inode = d_inode(dentry);
69	if (!inode)
70		goto out_valid;
71
72	v9inode = V9FS_I(inode);
73	if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
74		int retval;
75		struct v9fs_session_info *v9ses;
76
77		fid = v9fs_fid_lookup(dentry);
78		if (IS_ERR(fid))
79			return PTR_ERR(fid);
80
81		v9ses = v9fs_inode2v9ses(inode);
82		if (v9fs_proto_dotl(v9ses))
83			retval = v9fs_refresh_inode_dotl(fid, inode);
84		else
85			retval = v9fs_refresh_inode(fid, inode);
86		p9_fid_put(fid);
87
88		if (retval == -ENOENT)
89			return 0;
90		if (retval < 0)
91			return retval;
92	}
93out_valid:
94	return 1;
95}
96
97const struct dentry_operations v9fs_cached_dentry_operations = {
98	.d_revalidate = v9fs_lookup_revalidate,
99	.d_weak_revalidate = v9fs_lookup_revalidate,
100	.d_delete = v9fs_cached_dentry_delete,
101	.d_release = v9fs_dentry_release,
102};
103
104const struct dentry_operations v9fs_dentry_operations = {
105	.d_delete = always_delete_dentry,
106	.d_release = v9fs_dentry_release,
107};
108