WSL2-Linux-Kernel/fs/9p/vfs_dentry.c

148 строки
3.5 KiB
C

/*
* linux/fs/9p/vfs_dentry.c
*
* This file contians vfs dentry ops for the 9P2000 protocol.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
/**
* v9fs_dentry_delete - called when dentry refcount equals 0
* @dentry: dentry in question
*
* By returning 1 here we should remove cacheing of unused
* dentry components.
*
*/
static int v9fs_dentry_delete(const struct dentry *dentry)
{
p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
dentry->d_name.name, dentry);
return 1;
}
/**
* v9fs_cached_dentry_delete - called when dentry refcount equals 0
* @dentry: dentry in question
*
*/
static int v9fs_cached_dentry_delete(const struct dentry *dentry)
{
p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
dentry->d_name.name, dentry);
/* Don't cache negative dentries */
if (!dentry->d_inode)
return 1;
return 0;
}
/**
* v9fs_dentry_release - called when dentry is going to be freed
* @dentry: dentry that is being release
*
*/
static void v9fs_dentry_release(struct dentry *dentry)
{
struct v9fs_dentry *dent;
struct p9_fid *temp, *current_fid;
p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
dentry->d_name.name, dentry);
dent = dentry->d_fsdata;
if (dent) {
list_for_each_entry_safe(current_fid, temp, &dent->fidlist,
dlist) {
p9_client_clunk(current_fid);
}
kfree(dent);
dentry->d_fsdata = NULL;
}
}
static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
{
struct p9_fid *fid;
struct inode *inode;
struct v9fs_inode *v9inode;
if (flags & LOOKUP_RCU)
return -ECHILD;
inode = dentry->d_inode;
if (!inode)
goto out_valid;
v9inode = V9FS_I(inode);
if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
int retval;
struct v9fs_session_info *v9ses;
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
v9ses = v9fs_inode2v9ses(inode);
if (v9fs_proto_dotl(v9ses))
retval = v9fs_refresh_inode_dotl(fid, inode);
else
retval = v9fs_refresh_inode(fid, inode);
if (retval == -ENOENT)
return 0;
if (retval < 0)
return retval;
}
out_valid:
return 1;
}
const struct dentry_operations v9fs_cached_dentry_operations = {
.d_revalidate = v9fs_lookup_revalidate,
.d_delete = v9fs_cached_dentry_delete,
.d_release = v9fs_dentry_release,
};
const struct dentry_operations v9fs_dentry_operations = {
.d_delete = v9fs_dentry_delete,
.d_release = v9fs_dentry_release,
};