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/*
* V9FS FID Management
*
* Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com>
*
* 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/sched.h>
#include <linux/idr.h>
#include <asm/semaphore.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
/**
* v9fs_fid_insert - add a fid to a dentry
* @fid: fid to add
* @dentry: dentry that it is being added to
*
*/
int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
{
struct v9fs_dentry *dent;
P9_DPRINTK(P9_DEBUG_VFS, "fid %d dentry %s\n",
fid->fid, dentry->d_iname);
dent = dentry->d_fsdata;
if (!dent) {
dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
if (!dent)
return -ENOMEM;
spin_lock_init(&dent->lock);
INIT_LIST_HEAD(&dent->fidlist);
dentry->d_fsdata = dent;
}
spin_lock(&dent->lock);
list_add(&fid->dlist, &dent->fidlist);
spin_unlock(&dent->lock);
return 0;
}
/**
* v9fs_fid_lookup - return a locked fid from a dentry
* @dentry: dentry to look for fid in
*
* find a fid in the dentry, obtain its semaphore and return a reference to it.
* code calling lookup is responsible for releasing lock
*
* TODO: only match fids that have the same uid as current user
*
*/
struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
{
struct v9fs_dentry *dent;
struct p9_fid *fid;
P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
dent = dentry->d_fsdata;
if (dent)
fid = list_entry(dent->fidlist.next, struct p9_fid, dlist);
else
fid = ERR_PTR(-EBADF);
P9_DPRINTK(P9_DEBUG_VFS, " fid: %p\n", fid);
return fid;
}
struct p9_fid *v9fs_fid_lookup_remove(struct dentry *dentry)
{
struct p9_fid *fid;
struct v9fs_dentry *dent;
dent = dentry->d_fsdata;
fid = v9fs_fid_lookup(dentry);
if (!IS_ERR(fid)) {
spin_lock(&dent->lock);
list_del(&fid->dlist);
spin_unlock(&dent->lock);
}
return fid;
}
/**
* v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
* release it
* @dentry: dentry to look for fid in
*
* find a fid in the dentry and then clone to a new private fid
*
* TODO: only match fids that have the same uid as current user
*
*/
struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
{
struct p9_fid *ofid, *fid;
P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
ofid = v9fs_fid_lookup(dentry);
if (IS_ERR(ofid))
return ofid;
fid = p9_client_walk(ofid, 0, NULL, 1);
return fid;
}
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