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Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -07001/*
2 * linux/fs/9p/vfs_dir.c
3 *
4 * This file contains vfs directory ops for the 9P2000 protocol.
5 *
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
Eric Van Hensbergen42e8c502006-03-25 03:07:28 -080010 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070012 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/file.h>
30#include <linux/stat.h>
31#include <linux/string.h>
Al Viro914e2632006-10-18 13:55:46 -040032#include <linux/sched.h>
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070033#include <linux/inet.h>
34#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050036#include <net/9p/9p.h>
37#include <net/9p/client.h>
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070038
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070039#include "v9fs.h"
Latchesar Ionkov531b1092006-01-08 01:05:00 -080040#include "v9fs_vfs.h"
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070041#include "fid.h"
42
43/**
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -060044 * struct p9_rdir - readdir accounting
45 * @mutex: mutex protecting readdir
46 * @head: start offset of current dirread buffer
47 * @tail: end offset of current dirread buffer
48 * @buf: dirread buffer
49 *
50 * private structure for keeping track of readdir
51 * allocated on demand
52 */
53
54struct p9_rdir {
55 struct mutex mutex;
56 int head;
57 int tail;
58 uint8_t *buf;
59};
60
61/**
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070062 * dt_type - return file type
63 * @mistat: mistat structure
64 *
65 */
66
Eric Van Hensbergen02da3982008-10-16 08:29:30 -050067static inline int dt_type(struct p9_wstat *mistat)
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070068{
69 unsigned long perm = mistat->mode;
70 int rettype = DT_REG;
71
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050072 if (perm & P9_DMDIR)
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070073 rettype = DT_DIR;
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -050074 if (perm & P9_DMSYMLINK)
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070075 rettype = DT_LNK;
76
77 return rettype;
78}
79
Aneesh Kumar K.Vfae45282010-03-06 04:44:16 +000080static void p9stat_init(struct p9_wstat *stbuf)
81{
82 stbuf->name = NULL;
83 stbuf->uid = NULL;
84 stbuf->gid = NULL;
85 stbuf->muid = NULL;
86 stbuf->extension = NULL;
87}
88
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -070089/**
Sripathi Kodi7751bdb2010-06-04 13:41:26 +000090 * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
91 * @filp: opened file structure
92 * @buflen: Length in bytes of buffer to allocate
93 *
94 */
95
96static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
97{
98 struct p9_rdir *rdir;
99 struct p9_fid *fid;
100 int err = 0;
101
102 fid = filp->private_data;
103 if (!fid->rdir) {
104 rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
105
106 if (rdir == NULL) {
107 err = -ENOMEM;
108 goto exit;
109 }
110 spin_lock(&filp->f_dentry->d_lock);
111 if (!fid->rdir) {
112 rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
113 mutex_init(&rdir->mutex);
114 rdir->head = rdir->tail = 0;
115 fid->rdir = (void *) rdir;
116 rdir = NULL;
117 }
118 spin_unlock(&filp->f_dentry->d_lock);
119 kfree(rdir);
120 }
121exit:
122 return err;
123}
124
125/**
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700126 * v9fs_dir_readdir - read a directory
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600127 * @filp: opened file structure
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700128 * @dirent: directory structure ???
129 * @filldir: function to populate directory structure ???
130 *
131 */
132
133static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
134{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500135 int over;
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500136 struct p9_wstat st;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600137 int err = 0;
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500138 struct p9_fid *fid;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500139 int buflen;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600140 int reclen = 0;
141 struct p9_rdir *rdir;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700142
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500143 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500144 fid = filp->private_data;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700145
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500146 buflen = fid->clnt->msize - P9_IOHDRSZ;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700147
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000148 err = v9fs_alloc_rdir_buf(filp, buflen);
149 if (err)
150 goto exit;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600151 rdir = (struct p9_rdir *) fid->rdir;
152
153 err = mutex_lock_interruptible(&rdir->mutex);
Dan Carpenter85a770a2010-03-30 09:41:25 +0000154 if (err)
155 return err;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600156 while (err == 0) {
157 if (rdir->tail == rdir->head) {
158 err = v9fs_file_readn(filp, rdir->buf, NULL,
159 buflen, filp->f_pos);
160 if (err <= 0)
161 goto unlock_and_exit;
162
163 rdir->head = 0;
164 rdir->tail = err;
165 }
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600166 while (rdir->head < rdir->tail) {
Aneesh Kumar K.Vfae45282010-03-06 04:44:16 +0000167 p9stat_init(&st);
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600168 err = p9stat_read(rdir->buf + rdir->head,
Latchesar Ionkovda7ddd32010-07-19 15:40:03 -0500169 rdir->tail - rdir->head, &st,
Sripathi Kodi342fee12010-03-05 18:50:14 +0000170 fid->clnt->proto_version);
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500171 if (err) {
172 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500173 err = -EIO;
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500174 p9stat_free(&st);
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600175 goto unlock_and_exit;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500176 }
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600177 reclen = st.size+2;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500178
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500179 over = filldir(dirent, st.name, strlen(st.name),
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500180 filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
181
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500182 p9stat_free(&st);
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500183
184 if (over) {
185 err = 0;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600186 goto unlock_and_exit;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500187 }
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600188 rdir->head += reclen;
189 filp->f_pos += reclen;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500190 }
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700191 }
192
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600193unlock_and_exit:
194 mutex_unlock(&rdir->mutex);
195exit:
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500196 return err;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700197}
198
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000199/**
200 * v9fs_dir_readdir_dotl - read a directory
201 * @filp: opened file structure
202 * @dirent: buffer to fill dirent structures
203 * @filldir: function to populate dirent structures
204 *
205 */
206static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
207 filldir_t filldir)
208{
209 int over;
210 int err = 0;
211 struct p9_fid *fid;
212 int buflen;
213 struct p9_rdir *rdir;
214 struct p9_dirent curdirent;
215 u64 oldoffset = 0;
216
217 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
218 fid = filp->private_data;
219
220 buflen = fid->clnt->msize - P9_READDIRHDRSZ;
221
222 err = v9fs_alloc_rdir_buf(filp, buflen);
223 if (err)
224 goto exit;
225 rdir = (struct p9_rdir *) fid->rdir;
226
227 err = mutex_lock_interruptible(&rdir->mutex);
228 if (err)
229 return err;
230
231 while (err == 0) {
232 if (rdir->tail == rdir->head) {
233 err = p9_client_readdir(fid, rdir->buf, buflen,
234 filp->f_pos);
235 if (err <= 0)
236 goto unlock_and_exit;
237
238 rdir->head = 0;
239 rdir->tail = err;
240 }
241
242 while (rdir->head < rdir->tail) {
243
244 err = p9dirent_read(rdir->buf + rdir->head,
245 buflen - rdir->head, &curdirent,
246 fid->clnt->proto_version);
247 if (err < 0) {
248 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
249 err = -EIO;
250 goto unlock_and_exit;
251 }
252
253 /* d_off in dirent structure tracks the offset into
254 * the next dirent in the dir. However, filldir()
255 * expects offset into the current dirent. Hence
256 * while calling filldir send the offset from the
257 * previous dirent structure.
258 */
259 over = filldir(dirent, curdirent.d_name,
260 strlen(curdirent.d_name),
261 oldoffset, v9fs_qid2ino(&curdirent.qid),
262 curdirent.d_type);
263 oldoffset = curdirent.d_off;
264
265 if (over) {
266 err = 0;
267 goto unlock_and_exit;
268 }
269
270 filp->f_pos = curdirent.d_off;
271 rdir->head += err;
272 }
273 }
274
275unlock_and_exit:
276 mutex_unlock(&rdir->mutex);
277exit:
278 return err;
279}
280
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500281
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700282/**
283 * v9fs_dir_release - close a directory
284 * @inode: inode of the directory
285 * @filp: file pointer to a directory
286 *
287 */
288
289int v9fs_dir_release(struct inode *inode, struct file *filp)
290{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500291 struct p9_fid *fid;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700292
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500293 fid = filp->private_data;
294 P9_DPRINTK(P9_DEBUG_VFS,
jvrao62726a72010-08-25 16:26:21 +0000295 "v9fs_dir_release: inode: %p filp: %p fid: %d\n",
296 inode, filp, fid ? fid->fid : -1);
OGAWA Hirofumi28fd1292006-01-08 01:02:14 -0800297 filemap_write_and_wait(inode->i_mapping);
jvrao62726a72010-08-25 16:26:21 +0000298 if (fid)
299 p9_client_clunk(fid);
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700300 return 0;
301}
302
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800303const struct file_operations v9fs_dir_operations = {
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700304 .read = generic_read_dir,
Al Viro59af1582008-08-24 07:24:41 -0400305 .llseek = generic_file_llseek,
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700306 .readdir = v9fs_dir_readdir,
307 .open = v9fs_file_open,
308 .release = v9fs_dir_release,
309};
Sripathi Kodi9b6533c2010-03-25 12:41:54 +0000310
311const struct file_operations v9fs_dir_operations_dotl = {
312 .read = generic_read_dir,
313 .llseek = generic_file_llseek,
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000314 .readdir = v9fs_dir_readdir_dotl,
Sripathi Kodi9b6533c2010-03-25 12:41:54 +0000315 .open = v9fs_file_open,
316 .release = v9fs_dir_release,
317};