vfs_dentry.c

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/*
 *  linux/fs/9p/vfs_dentry.c
 *
 * This file contians vfs dentry ops for the 9P2000 protocol.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <[email protected]>
 *  Copyright (C) 2002 by Ron Minnich <[email protected]>
 *
 *  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"

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;
}

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;
}

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,
};