4 * Copyright (C) 2005, 2006 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 version 2
8 * as published by the Free Software Foundation.
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.
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
23 #include <linux/module.h>
24 #include <linux/errno.h>
26 #include <linux/sched.h>
27 #include <linux/idr.h>
28 #include <asm/semaphore.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 list_add(&fid
->list
, fid_list
);
65 * v9fs_fid_create - allocate a FID structure
66 * @dentry - dentry to link newly created fid to
70 struct v9fs_fid
*v9fs_fid_create(struct v9fs_session_info
*v9ses
, int fid
)
74 dprintk(DEBUG_9P
, "fid create fid %d\n", fid
);
75 new = kmalloc(sizeof(struct v9fs_fid
), GFP_KERNEL
);
77 dprintk(DEBUG_ERROR
, "Out of Memory\n");
78 return ERR_PTR(-ENOMEM
);
87 new->rdir_fcall
= NULL
;
88 init_MUTEX(&new->lock
);
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_lookup - return a locked fid from a dentry
108 * @dentry: dentry to look for fid in
110 * find a fid in the dentry, obtain its semaphore and return a reference to it.
111 * code calling lookup is responsible for releasing lock
113 * TODO: only match fids that have the same uid as current user
117 struct v9fs_fid
*v9fs_fid_lookup(struct dentry
*dentry
)
119 struct list_head
*fid_list
= (struct list_head
*)dentry
->d_fsdata
;
120 struct v9fs_fid
*return_fid
= NULL
;
122 dprintk(DEBUG_9P
, " dentry: %s (%p)\n", dentry
->d_iname
, dentry
);
125 return_fid
= list_entry(fid_list
->next
, struct v9fs_fid
, list
);
128 dprintk(DEBUG_ERROR
, "Couldn't find a fid in dentry\n");
129 return_fid
= ERR_PTR(-EBADF
);
132 if(down_interruptible(&return_fid
->lock
))
133 return ERR_PTR(-EINTR
);
139 * v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
141 * @dentry: dentry to look for fid in
143 * find a fid in the dentry and then clone to a new private fid
145 * TODO: only match fids that have the same uid as current user
149 struct v9fs_fid
*v9fs_fid_clone(struct dentry
*dentry
)
151 struct v9fs_session_info
*v9ses
= v9fs_inode2v9ses(dentry
->d_inode
);
152 struct v9fs_fid
*base_fid
, *new_fid
= ERR_PTR(-EBADF
);
153 struct v9fs_fcall
*fcall
= NULL
;
156 base_fid
= v9fs_fid_lookup(dentry
);
161 if(base_fid
) { /* clone fid */
162 fid
= v9fs_get_idpool(&v9ses
->fidpool
);
164 eprintk(KERN_WARNING
, "newfid fails!\n");
165 new_fid
= ERR_PTR(-ENOSPC
);
169 err
= v9fs_t_walk(v9ses
, base_fid
->fid
, fid
, NULL
, &fcall
);
171 dprintk(DEBUG_ERROR
, "clone walk didn't work\n");
172 v9fs_put_idpool(fid
, &v9ses
->fidpool
);
173 new_fid
= ERR_PTR(err
);
176 new_fid
= v9fs_fid_create(v9ses
, fid
);
177 if (new_fid
== NULL
) {
178 dprintk(DEBUG_ERROR
, "out of memory\n");
179 new_fid
= ERR_PTR(-ENOMEM
);
190 void v9fs_fid_clunk(struct v9fs_session_info
*v9ses
, struct v9fs_fid
*fid
)
192 v9fs_t_clunk(v9ses
, fid
->fid
);
193 v9fs_fid_destroy(fid
);