4 * Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to:
18 * Free Software Foundation
19 * 51 Franklin Street, Fifth Floor
20 * Boston, MA 02111-1301 USA
24 #include <linux/config.h>
25 #include <linux/module.h>
26 #include <linux/errno.h>
28 #include <linux/idr.h>
37 * v9fs_fid_insert - add a fid to a dentry
39 * @dentry: dentry that it is being added to
43 int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
45 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
46 dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid,
47 dentry->d_iname, dentry);
48 if (dentry->d_fsdata == NULL) {
50 kmalloc(sizeof(struct list_head), GFP_KERNEL);
51 if (dentry->d_fsdata == NULL) {
52 dprintk(DEBUG_ERROR, "Out of memory\n");
55 fid_list = (struct list_head *)dentry->d_fsdata;
56 INIT_LIST_HEAD(fid_list); /* Initialize list head */
59 fid->uid = current->uid;
60 fid->pid = current->pid;
61 list_add(&fid->list, fid_list);
66 * v9fs_fid_create - allocate a FID structure
67 * @dentry - dentry to link newly created fid to
71 struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *v9ses, int fid)
75 dprintk(DEBUG_9P, "fid create fid %d\n", fid);
76 new = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
78 dprintk(DEBUG_ERROR, "Out of Memory\n");
79 return ERR_PTR(-ENOMEM);
88 new->rdir_fcall = NULL;
89 INIT_LIST_HEAD(&new->list);
95 * v9fs_fid_destroy - deallocate a FID structure
96 * @fid: fid to destroy
100 void v9fs_fid_destroy(struct v9fs_fid *fid)
102 list_del(&fid->list);
107 * v9fs_fid_walk_up - walks from the process current directory
108 * up to the specified dentry.
110 static struct v9fs_fid *v9fs_fid_walk_up(struct dentry *dentry)
112 int fidnum, cfidnum, err;
113 struct v9fs_fid *cfid, *fid;
115 struct v9fs_session_info *v9ses;
117 v9ses = v9fs_inode2v9ses(current->fs->pwd->d_inode);
118 cfid = v9fs_fid_lookup(current->fs->pwd);
120 dprintk(DEBUG_ERROR, "process cwd doesn't have a fid\n");
121 return ERR_PTR(-ENOENT);
125 cde = current->fs->pwd;
126 /* TODO: take advantage of multiwalk */
128 fidnum = v9fs_get_idpool(&v9ses->fidpool);
130 dprintk(DEBUG_ERROR, "could not get a new fid num\n");
135 while (cde != dentry) {
136 if (cde == cde->d_parent) {
137 dprintk(DEBUG_ERROR, "can't find dentry\n");
142 err = v9fs_t_walk(v9ses, cfidnum, fidnum, "..", NULL);
144 dprintk(DEBUG_ERROR, "problem walking to parent\n");
152 fid = v9fs_fid_create(v9ses, fidnum);
154 err = v9fs_fid_insert(fid, dentry);
164 v9fs_t_clunk(v9ses, fidnum);
169 * v9fs_fid_lookup - retrieve the right fid from a particular dentry
170 * @dentry: dentry to look for fid in
171 * @type: intent of lookup (operation or traversal)
173 * search list of fids associated with a dentry for a fid with a matching
174 * thread id or uid. If that fails, look up the dentry's parents to see if you
175 * can find a matching fid.
179 struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry)
181 struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
182 struct v9fs_fid *return_fid = NULL;
184 dprintk(DEBUG_9P, " dentry: %s (%p)\n", dentry->d_iname, dentry);
187 return_fid = list_entry(fid_list->next, struct v9fs_fid, list);
190 struct dentry *par = current->fs->pwd->d_parent;
192 while (par != NULL) {
196 if (par == par->d_parent) {
198 "got to root without finding dentry\n");
204 /* XXX - there may be some duplication we can get rid of */
206 return_fid = v9fs_fid_walk_up(dentry);
207 if (IS_ERR(return_fid))