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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);
Aneesh Kumar K.V348b5902011-08-07 00:46:59 +0530168 err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
169 rdir->tail - rdir->head, &st);
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500170 if (err) {
171 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500172 err = -EIO;
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500173 p9stat_free(&st);
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600174 goto unlock_and_exit;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500175 }
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600176 reclen = st.size+2;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500177
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500178 over = filldir(dirent, st.name, strlen(st.name),
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500179 filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
180
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500181 p9stat_free(&st);
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500182
183 if (over) {
184 err = 0;
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600185 goto unlock_and_exit;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500186 }
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600187 rdir->head += reclen;
188 filp->f_pos += reclen;
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500189 }
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700190 }
191
Eric Van Hensbergen3e2796a2009-11-02 08:39:28 -0600192unlock_and_exit:
193 mutex_unlock(&rdir->mutex);
194exit:
Eric Van Hensbergen06b55b42008-10-13 20:36:15 -0500195 return err;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700196}
197
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000198/**
199 * v9fs_dir_readdir_dotl - read a directory
200 * @filp: opened file structure
201 * @dirent: buffer to fill dirent structures
202 * @filldir: function to populate dirent structures
203 *
204 */
205static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
206 filldir_t filldir)
207{
208 int over;
209 int err = 0;
210 struct p9_fid *fid;
211 int buflen;
212 struct p9_rdir *rdir;
213 struct p9_dirent curdirent;
214 u64 oldoffset = 0;
215
216 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
217 fid = filp->private_data;
218
219 buflen = fid->clnt->msize - P9_READDIRHDRSZ;
220
221 err = v9fs_alloc_rdir_buf(filp, buflen);
222 if (err)
223 goto exit;
224 rdir = (struct p9_rdir *) fid->rdir;
225
226 err = mutex_lock_interruptible(&rdir->mutex);
227 if (err)
228 return err;
229
230 while (err == 0) {
231 if (rdir->tail == rdir->head) {
232 err = p9_client_readdir(fid, rdir->buf, buflen,
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530233 filp->f_pos);
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000234 if (err <= 0)
235 goto unlock_and_exit;
236
237 rdir->head = 0;
238 rdir->tail = err;
239 }
240
241 while (rdir->head < rdir->tail) {
242
Aneesh Kumar K.V348b5902011-08-07 00:46:59 +0530243 err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
244 rdir->tail - rdir->head,
245 &curdirent);
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000246 if (err < 0) {
247 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
248 err = -EIO;
249 goto unlock_and_exit;
250 }
251
252 /* d_off in dirent structure tracks the offset into
253 * the next dirent in the dir. However, filldir()
254 * expects offset into the current dirent. Hence
255 * while calling filldir send the offset from the
256 * previous dirent structure.
257 */
258 over = filldir(dirent, curdirent.d_name,
259 strlen(curdirent.d_name),
260 oldoffset, v9fs_qid2ino(&curdirent.qid),
261 curdirent.d_type);
262 oldoffset = curdirent.d_off;
263
264 if (over) {
265 err = 0;
266 goto unlock_and_exit;
267 }
268
269 filp->f_pos = curdirent.d_off;
270 rdir->head += err;
271 }
272 }
273
274unlock_and_exit:
275 mutex_unlock(&rdir->mutex);
276exit:
277 return err;
278}
279
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500280
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700281/**
282 * v9fs_dir_release - close a directory
283 * @inode: inode of the directory
284 * @filp: file pointer to a directory
285 *
286 */
287
288int v9fs_dir_release(struct inode *inode, struct file *filp)
289{
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500290 struct p9_fid *fid;
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700291
Latchesar Ionkovbd238fb2007-07-10 17:57:28 -0500292 fid = filp->private_data;
293 P9_DPRINTK(P9_DEBUG_VFS,
jvrao62726a72010-08-25 16:26:21 +0000294 "v9fs_dir_release: inode: %p filp: %p fid: %d\n",
295 inode, filp, fid ? fid->fid : -1);
jvrao62726a72010-08-25 16:26:21 +0000296 if (fid)
297 p9_client_clunk(fid);
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700298 return 0;
299}
300
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800301const struct file_operations v9fs_dir_operations = {
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700302 .read = generic_read_dir,
Al Viro59af1582008-08-24 07:24:41 -0400303 .llseek = generic_file_llseek,
Eric Van Hensbergene69e7fe2005-09-09 13:04:18 -0700304 .readdir = v9fs_dir_readdir,
305 .open = v9fs_file_open,
306 .release = v9fs_dir_release,
307};
Sripathi Kodi9b6533c2010-03-25 12:41:54 +0000308
309const struct file_operations v9fs_dir_operations_dotl = {
310 .read = generic_read_dir,
311 .llseek = generic_file_llseek,
Sripathi Kodi7751bdb2010-06-04 13:41:26 +0000312 .readdir = v9fs_dir_readdir_dotl,
Sripathi Kodi9b6533c2010-03-25 12:41:54 +0000313 .open = v9fs_file_open,
314 .release = v9fs_dir_release,
Venkateswararao Jujjuri (JV)b165d602010-10-22 10:13:12 -0700315 .fsync = v9fs_file_fsync_dotl,
Sripathi Kodi9b6533c2010-03-25 12:41:54 +0000316};