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Eric Van Hensbergen3ed84912005-09-09 13:04:24 -07001/*
2 * V9FS FID Management
3 *
Eric Van Hensbergen46f6dac2006-03-02 02:54:33 -08004 * Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com>
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -07005 *
6 * This program is free software; you can redistribute it and/or modify
Eric Van Hensbergen42e8c502006-03-25 03:07:28 -08007 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -07009 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to:
17 * Free Software Foundation
18 * 51 Franklin Street, Fifth Floor
19 * Boston, MA 02111-1301 USA
20 *
21 */
22
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070023#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/fs.h>
Al Viro914e2632006-10-18 13:55:46 -040026#include <linux/sched.h>
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070027#include <linux/idr.h>
Eric Van Hensbergenda977b22007-01-26 00:57:06 -080028#include <asm/semaphore.h>
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050029#include <net/9p/9p.h>
30#include <net/9p/client.h>
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070031
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070032#include "v9fs.h"
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070033#include "v9fs_vfs.h"
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070034#include "fid.h"
35
36/**
37 * v9fs_fid_insert - add a fid to a dentry
38 * @fid: fid to add
39 * @dentry: dentry that it is being added to
40 *
41 */
42
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050043int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070044{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050045 struct v9fs_dentry *dent;
46
47 P9_DPRINTK(P9_DEBUG_VFS, "fid %d dentry %s\n",
48 fid->fid, dentry->d_iname);
49
50 dent = dentry->d_fsdata;
51 if (!dent) {
52 dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
53 if (!dent)
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070054 return -ENOMEM;
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050055
56 spin_lock_init(&dent->lock);
57 INIT_LIST_HEAD(&dent->fidlist);
58 dentry->d_fsdata = dent;
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070059 }
60
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050061 spin_lock(&dent->lock);
62 list_add(&fid->dlist, &dent->fidlist);
63 spin_unlock(&dent->lock);
64
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070065 return 0;
66}
67
68/**
Eric Van Hensbergenda977b22007-01-26 00:57:06 -080069 * v9fs_fid_lookup - return a locked fid from a dentry
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070070 * @dentry: dentry to look for fid in
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070071 *
Eric Van Hensbergenda977b22007-01-26 00:57:06 -080072 * find a fid in the dentry, obtain its semaphore and return a reference to it.
73 * code calling lookup is responsible for releasing lock
Eric Van Hensbergen46f6dac2006-03-02 02:54:33 -080074 *
75 * TODO: only match fids that have the same uid as current user
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070076 *
77 */
78
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050079struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070080{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050081 struct v9fs_dentry *dent;
82 struct p9_fid *fid;
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070083
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050084 P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
85 dent = dentry->d_fsdata;
86 if (dent)
87 fid = list_entry(dent->fidlist.next, struct p9_fid, dlist);
88 else
89 fid = ERR_PTR(-EBADF);
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070090
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050091 P9_DPRINTK(P9_DEBUG_VFS, " fid: %p\n", fid);
92 return fid;
93}
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -070094
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050095struct p9_fid *v9fs_fid_lookup_remove(struct dentry *dentry)
96{
97 struct p9_fid *fid;
98 struct v9fs_dentry *dent;
99
100 dent = dentry->d_fsdata;
101 fid = v9fs_fid_lookup(dentry);
102 if (!IS_ERR(fid)) {
103 spin_lock(&dent->lock);
104 list_del(&fid->dlist);
105 spin_unlock(&dent->lock);
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -0700106 }
107
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500108 return fid;
Eric Van Hensbergen3ed84912005-09-09 13:04:24 -0700109}
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800110
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500111
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800112/**
Eric Van Hensbergene03abc02007-02-11 13:21:39 -0600113 * v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500114 * release it
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800115 * @dentry: dentry to look for fid in
116 *
117 * find a fid in the dentry and then clone to a new private fid
118 *
119 * TODO: only match fids that have the same uid as current user
120 *
121 */
122
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500123struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800124{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500125 struct p9_fid *ofid, *fid;
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800126
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500127 P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
128 ofid = v9fs_fid_lookup(dentry);
129 if (IS_ERR(ofid))
130 return ofid;
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800131
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500132 fid = p9_client_walk(ofid, 0, NULL, 1);
133 return fid;
Eric Van Hensbergenda977b22007-01-26 00:57:06 -0800134}