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 static 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 dentry
*dentry
,
72 struct v9fs_session_info
*v9ses
, int fid
, int create
)
76 dprintk(DEBUG_9P
, "fid create dentry %p, fid %d, create %d\n",
79 new = kmalloc(sizeof(struct v9fs_fid
), GFP_KERNEL
);
81 dprintk(DEBUG_ERROR
, "Out of Memory\n");
82 return ERR_PTR(-ENOMEM
);
88 new->fidcreate
= create
;
92 new->rdir_fcall
= NULL
;
94 if (v9fs_fid_insert(new, dentry
) == 0)
97 dprintk(DEBUG_ERROR
, "Problems inserting to dentry\n");
104 * v9fs_fid_destroy - deallocate a FID structure
105 * @fid: fid to destroy
109 void v9fs_fid_destroy(struct v9fs_fid
*fid
)
111 list_del(&fid
->list
);
116 * v9fs_fid_walk_up - walks from the process current directory
117 * up to the specified dentry.
119 static struct v9fs_fid
*v9fs_fid_walk_up(struct dentry
*dentry
)
121 int fidnum
, cfidnum
, err
;
122 struct v9fs_fid
*cfid
;
124 struct v9fs_session_info
*v9ses
;
126 v9ses
= v9fs_inode2v9ses(current
->fs
->pwd
->d_inode
);
127 cfid
= v9fs_fid_lookup(current
->fs
->pwd
);
129 dprintk(DEBUG_ERROR
, "process cwd doesn't have a fid\n");
130 return ERR_PTR(-ENOENT
);
134 cde
= current
->fs
->pwd
;
135 /* TODO: take advantage of multiwalk */
137 fidnum
= v9fs_get_idpool(&v9ses
->fidpool
);
139 dprintk(DEBUG_ERROR
, "could not get a new fid num\n");
144 while (cde
!= dentry
) {
145 if (cde
== cde
->d_parent
) {
146 dprintk(DEBUG_ERROR
, "can't find dentry\n");
151 err
= v9fs_t_walk(v9ses
, cfidnum
, fidnum
, "..", NULL
);
153 dprintk(DEBUG_ERROR
, "problem walking to parent\n");
161 return v9fs_fid_create(dentry
, v9ses
, fidnum
, 0);
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
*current_fid
= NULL
;
183 struct v9fs_fid
*temp
= NULL
;
184 struct v9fs_fid
*return_fid
= NULL
;
186 dprintk(DEBUG_9P
, " dentry: %s (%p)\n", dentry
->d_iname
, dentry
);
189 list_for_each_entry_safe(current_fid
, temp
, fid_list
, list
) {
190 if (!current_fid
->fidcreate
) {
191 return_fid
= current_fid
;
197 return_fid
= current_fid
;
200 /* we are at the root but didn't match */
201 if ((!return_fid
) && (dentry
->d_parent
== dentry
)) {
202 /* TODO: clone attach with new uid */
203 return_fid
= current_fid
;
207 struct dentry
*par
= current
->fs
->pwd
->d_parent
;
209 while (par
!= NULL
) {
213 if (par
== par
->d_parent
) {
215 "got to root without finding dentry\n");
221 /* XXX - there may be some duplication we can get rid of */
223 return_fid
= v9fs_fid_walk_up(dentry
);
224 if (IS_ERR(return_fid
))
232 struct v9fs_fid
*v9fs_fid_get_created(struct dentry
*dentry
)
234 struct list_head
*fid_list
;
235 struct v9fs_fid
*fid
, *ftmp
, *ret
;
237 dprintk(DEBUG_9P
, " dentry: %s (%p)\n", dentry
->d_iname
, dentry
);
238 fid_list
= (struct list_head
*)dentry
->d_fsdata
;
241 list_for_each_entry_safe(fid
, ftmp
, fid_list
, list
) {
242 if (fid
->fidcreate
&& fid
->pid
== current
->pid
) {
243 list_del(&fid
->list
);
250 dprintk(DEBUG_9P
, "return %p\n", ret
);