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1/*
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
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
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>
32#include <linux/sched.h>
33#include <linux/inet.h>
34#include <linux/idr.h>
35#include <linux/slab.h>
36#include <net/9p/9p.h>
37#include <net/9p/client.h>
38
39#include "v9fs.h"
40#include "v9fs_vfs.h"
41#include "fid.h"
42
43/**
44 * 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/**
62 * dt_type - return file type
63 * @mistat: mistat structure
64 *
65 */
66
67static inline int dt_type(struct p9_wstat *mistat)
68{
69 unsigned long perm = mistat->mode;
70 int rettype = DT_REG;
71
72 if (perm & P9_DMDIR)
73 rettype = DT_DIR;
74 if (perm & P9_DMSYMLINK)
75 rettype = DT_LNK;
76
77 return rettype;
78}
79
80static 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
89/**
90 * 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/**
126 * v9fs_dir_readdir - read a directory
127 * @filp: opened file structure
128 * @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{
135 int over;
136 struct p9_wstat st;
137 int err = 0;
138 struct p9_fid *fid;
139 int buflen;
140 int reclen = 0;
141 struct p9_rdir *rdir;
142
143 P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
144 fid = filp->private_data;
145
146 buflen = fid->clnt->msize - P9_IOHDRSZ;
147
148 err = v9fs_alloc_rdir_buf(filp, buflen);
149 if (err)
150 goto exit;
151 rdir = (struct p9_rdir *) fid->rdir;
152
153 err = mutex_lock_interruptible(&rdir->mutex);
154 if (err)
155 return err;
156 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 }
166 while (rdir->head < rdir->tail) {
167 p9stat_init(&st);
168 err = p9stat_read(rdir->buf + rdir->head,
169 rdir->tail - rdir->head, &st,
170 fid->clnt->proto_version);
171 if (err) {
172 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
173 err = -EIO;
174 p9stat_free(&st);
175 goto unlock_and_exit;
176 }
177 reclen = st.size+2;
178
179 over = filldir(dirent, st.name, strlen(st.name),
180 filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
181
182 p9stat_free(&st);
183
184 if (over) {
185 err = 0;
186 goto unlock_and_exit;
187 }
188 rdir->head += reclen;
189 filp->f_pos += reclen;
190 }
191 }
192
193unlock_and_exit:
194 mutex_unlock(&rdir->mutex);
195exit:
196 return err;
197}
198
199/**
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 rdir->tail - rdir->head,
246 &curdirent,
247 fid->clnt->proto_version);
248 if (err < 0) {
249 P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
250 err = -EIO;
251 goto unlock_and_exit;
252 }
253
254 /* d_off in dirent structure tracks the offset into
255 * the next dirent in the dir. However, filldir()
256 * expects offset into the current dirent. Hence
257 * while calling filldir send the offset from the
258 * previous dirent structure.
259 */
260 over = filldir(dirent, curdirent.d_name,
261 strlen(curdirent.d_name),
262 oldoffset, v9fs_qid2ino(&curdirent.qid),
263 curdirent.d_type);
264 oldoffset = curdirent.d_off;
265
266 if (over) {
267 err = 0;
268 goto unlock_and_exit;
269 }
270
271 filp->f_pos = curdirent.d_off;
272 rdir->head += err;
273 }
274 }
275
276unlock_and_exit:
277 mutex_unlock(&rdir->mutex);
278exit:
279 return err;
280}
281
282
283/**
284 * v9fs_dir_release - close a directory
285 * @inode: inode of the directory
286 * @filp: file pointer to a directory
287 *
288 */
289
290int v9fs_dir_release(struct inode *inode, struct file *filp)
291{
292 struct p9_fid *fid;
293
294 fid = filp->private_data;
295 P9_DPRINTK(P9_DEBUG_VFS,
296 "v9fs_dir_release: inode: %p filp: %p fid: %d\n",
297 inode, filp, fid ? fid->fid : -1);
298 if (fid)
299 p9_client_clunk(fid);
300 return 0;
301}
302
303const struct file_operations v9fs_dir_operations = {
304 .read = generic_read_dir,
305 .llseek = generic_file_llseek,
306 .readdir = v9fs_dir_readdir,
307 .open = v9fs_file_open,
308 .release = v9fs_dir_release,
309};
310
311const struct file_operations v9fs_dir_operations_dotl = {
312 .read = generic_read_dir,
313 .llseek = generic_file_llseek,
314 .readdir = v9fs_dir_readdir_dotl,
315 .open = v9fs_file_open,
316 .release = v9fs_dir_release,
317 .fsync = v9fs_file_fsync_dotl,
318};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/9p/vfs_dir.c
4 *
5 * This file contains vfs directory ops for the 9P2000 protocol.
6 *
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 */
10
11#include <linux/module.h>
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/file.h>
15#include <linux/stat.h>
16#include <linux/string.h>
17#include <linux/sched.h>
18#include <linux/inet.h>
19#include <linux/idr.h>
20#include <linux/slab.h>
21#include <linux/uio.h>
22#include <net/9p/9p.h>
23#include <net/9p/client.h>
24
25#include "v9fs.h"
26#include "v9fs_vfs.h"
27#include "fid.h"
28
29/**
30 * struct p9_rdir - readdir accounting
31 * @head: start offset of current dirread buffer
32 * @tail: end offset of current dirread buffer
33 * @buf: dirread buffer
34 *
35 * private structure for keeping track of readdir
36 * allocated on demand
37 */
38
39struct p9_rdir {
40 int head;
41 int tail;
42 uint8_t buf[];
43};
44
45/**
46 * dt_type - return file type
47 * @mistat: mistat structure
48 *
49 */
50
51static inline int dt_type(struct p9_wstat *mistat)
52{
53 unsigned long perm = mistat->mode;
54 int rettype = DT_REG;
55
56 if (perm & P9_DMDIR)
57 rettype = DT_DIR;
58 if (perm & P9_DMSYMLINK)
59 rettype = DT_LNK;
60
61 return rettype;
62}
63
64/**
65 * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
66 * @filp: opened file structure
67 * @buflen: Length in bytes of buffer to allocate
68 *
69 */
70
71static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen)
72{
73 struct p9_fid *fid = filp->private_data;
74 if (!fid->rdir)
75 fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
76 return fid->rdir;
77}
78
79/**
80 * v9fs_dir_readdir - iterate through a directory
81 * @file: opened file structure
82 * @ctx: actor we feed the entries to
83 *
84 */
85
86static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
87{
88 bool over;
89 struct p9_wstat st;
90 int err = 0;
91 struct p9_fid *fid;
92 int buflen;
93 struct p9_rdir *rdir;
94 struct kvec kvec;
95
96 p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
97 fid = file->private_data;
98
99 buflen = fid->clnt->msize - P9_IOHDRSZ;
100
101 rdir = v9fs_alloc_rdir_buf(file, buflen);
102 if (!rdir)
103 return -ENOMEM;
104 kvec.iov_base = rdir->buf;
105 kvec.iov_len = buflen;
106
107 while (1) {
108 if (rdir->tail == rdir->head) {
109 struct iov_iter to;
110 int n;
111 iov_iter_kvec(&to, READ, &kvec, 1, buflen);
112 n = p9_client_read(file->private_data, ctx->pos, &to,
113 &err);
114 if (err)
115 return err;
116 if (n == 0)
117 return 0;
118
119 rdir->head = 0;
120 rdir->tail = n;
121 }
122 while (rdir->head < rdir->tail) {
123 err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
124 rdir->tail - rdir->head, &st);
125 if (err <= 0) {
126 p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
127 return -EIO;
128 }
129
130 over = !dir_emit(ctx, st.name, strlen(st.name),
131 v9fs_qid2ino(&st.qid), dt_type(&st));
132 p9stat_free(&st);
133 if (over)
134 return 0;
135
136 rdir->head += err;
137 ctx->pos += err;
138 }
139 }
140}
141
142/**
143 * v9fs_dir_readdir_dotl - iterate through a directory
144 * @file: opened file structure
145 * @ctx: actor we feed the entries to
146 *
147 */
148static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
149{
150 int err = 0;
151 struct p9_fid *fid;
152 int buflen;
153 struct p9_rdir *rdir;
154 struct p9_dirent curdirent;
155
156 p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
157 fid = file->private_data;
158
159 buflen = fid->clnt->msize - P9_READDIRHDRSZ;
160
161 rdir = v9fs_alloc_rdir_buf(file, buflen);
162 if (!rdir)
163 return -ENOMEM;
164
165 while (1) {
166 if (rdir->tail == rdir->head) {
167 err = p9_client_readdir(fid, rdir->buf, buflen,
168 ctx->pos);
169 if (err <= 0)
170 return err;
171
172 rdir->head = 0;
173 rdir->tail = err;
174 }
175
176 while (rdir->head < rdir->tail) {
177
178 err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
179 rdir->tail - rdir->head,
180 &curdirent);
181 if (err < 0) {
182 p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
183 return -EIO;
184 }
185
186 if (!dir_emit(ctx, curdirent.d_name,
187 strlen(curdirent.d_name),
188 v9fs_qid2ino(&curdirent.qid),
189 curdirent.d_type))
190 return 0;
191
192 ctx->pos = curdirent.d_off;
193 rdir->head += err;
194 }
195 }
196}
197
198
199/**
200 * v9fs_dir_release - close a directory
201 * @inode: inode of the directory
202 * @filp: file pointer to a directory
203 *
204 */
205
206int v9fs_dir_release(struct inode *inode, struct file *filp)
207{
208 struct p9_fid *fid;
209
210 fid = filp->private_data;
211 p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
212 inode, filp, fid ? fid->fid : -1);
213 if (fid) {
214 spin_lock(&inode->i_lock);
215 hlist_del(&fid->ilist);
216 spin_unlock(&inode->i_lock);
217 p9_client_clunk(fid);
218 }
219 return 0;
220}
221
222const struct file_operations v9fs_dir_operations = {
223 .read = generic_read_dir,
224 .llseek = generic_file_llseek,
225 .iterate_shared = v9fs_dir_readdir,
226 .open = v9fs_file_open,
227 .release = v9fs_dir_release,
228};
229
230const struct file_operations v9fs_dir_operations_dotl = {
231 .read = generic_read_dir,
232 .llseek = generic_file_llseek,
233 .iterate_shared = v9fs_dir_readdir_dotl,
234 .open = v9fs_file_open,
235 .release = v9fs_dir_release,
236 .fsync = v9fs_file_fsync_dotl,
237};