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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 <linux/uio.h>
37#include <net/9p/9p.h>
38#include <net/9p/client.h>
39
40#include "v9fs.h"
41#include "v9fs_vfs.h"
42#include "fid.h"
43
44/**
45 * struct p9_rdir - readdir accounting
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 int head;
56 int tail;
57 uint8_t buf[];
58};
59
60/**
61 * dt_type - return file type
62 * @mistat: mistat structure
63 *
64 */
65
66static inline int dt_type(struct p9_wstat *mistat)
67{
68 unsigned long perm = mistat->mode;
69 int rettype = DT_REG;
70
71 if (perm & P9_DMDIR)
72 rettype = DT_DIR;
73 if (perm & P9_DMSYMLINK)
74 rettype = DT_LNK;
75
76 return rettype;
77}
78
79static void p9stat_init(struct p9_wstat *stbuf)
80{
81 stbuf->name = NULL;
82 stbuf->uid = NULL;
83 stbuf->gid = NULL;
84 stbuf->muid = NULL;
85 stbuf->extension = NULL;
86}
87
88/**
89 * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
90 * @filp: opened file structure
91 * @buflen: Length in bytes of buffer to allocate
92 *
93 */
94
95static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen)
96{
97 struct p9_fid *fid = filp->private_data;
98 if (!fid->rdir)
99 fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
100 return fid->rdir;
101}
102
103/**
104 * v9fs_dir_readdir - iterate through a directory
105 * @file: opened file structure
106 * @ctx: actor we feed the entries to
107 *
108 */
109
110static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
111{
112 bool over;
113 struct p9_wstat st;
114 int err = 0;
115 struct p9_fid *fid;
116 int buflen;
117 int reclen = 0;
118 struct p9_rdir *rdir;
119 struct kvec kvec;
120
121 p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
122 fid = file->private_data;
123
124 buflen = fid->clnt->msize - P9_IOHDRSZ;
125
126 rdir = v9fs_alloc_rdir_buf(file, buflen);
127 if (!rdir)
128 return -ENOMEM;
129 kvec.iov_base = rdir->buf;
130 kvec.iov_len = buflen;
131
132 while (1) {
133 if (rdir->tail == rdir->head) {
134 struct iov_iter to;
135 int n;
136 iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
137 n = p9_client_read(file->private_data, ctx->pos, &to,
138 &err);
139 if (err)
140 return err;
141 if (n == 0)
142 return 0;
143
144 rdir->head = 0;
145 rdir->tail = n;
146 }
147 while (rdir->head < rdir->tail) {
148 p9stat_init(&st);
149 err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
150 rdir->tail - rdir->head, &st);
151 if (err) {
152 p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
153 p9stat_free(&st);
154 return -EIO;
155 }
156 reclen = st.size+2;
157
158 over = !dir_emit(ctx, st.name, strlen(st.name),
159 v9fs_qid2ino(&st.qid), dt_type(&st));
160 p9stat_free(&st);
161 if (over)
162 return 0;
163
164 rdir->head += reclen;
165 ctx->pos += reclen;
166 }
167 }
168}
169
170/**
171 * v9fs_dir_readdir_dotl - iterate through a directory
172 * @file: opened file structure
173 * @ctx: actor we feed the entries to
174 *
175 */
176static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
177{
178 int err = 0;
179 struct p9_fid *fid;
180 int buflen;
181 struct p9_rdir *rdir;
182 struct p9_dirent curdirent;
183
184 p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
185 fid = file->private_data;
186
187 buflen = fid->clnt->msize - P9_READDIRHDRSZ;
188
189 rdir = v9fs_alloc_rdir_buf(file, buflen);
190 if (!rdir)
191 return -ENOMEM;
192
193 while (1) {
194 if (rdir->tail == rdir->head) {
195 err = p9_client_readdir(fid, rdir->buf, buflen,
196 ctx->pos);
197 if (err <= 0)
198 return err;
199
200 rdir->head = 0;
201 rdir->tail = err;
202 }
203
204 while (rdir->head < rdir->tail) {
205
206 err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
207 rdir->tail - rdir->head,
208 &curdirent);
209 if (err < 0) {
210 p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
211 return -EIO;
212 }
213
214 if (!dir_emit(ctx, curdirent.d_name,
215 strlen(curdirent.d_name),
216 v9fs_qid2ino(&curdirent.qid),
217 curdirent.d_type))
218 return 0;
219
220 ctx->pos = curdirent.d_off;
221 rdir->head += err;
222 }
223 }
224}
225
226
227/**
228 * v9fs_dir_release - close a directory
229 * @inode: inode of the directory
230 * @filp: file pointer to a directory
231 *
232 */
233
234int v9fs_dir_release(struct inode *inode, struct file *filp)
235{
236 struct p9_fid *fid;
237
238 fid = filp->private_data;
239 p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
240 inode, filp, fid ? fid->fid : -1);
241 if (fid)
242 p9_client_clunk(fid);
243 return 0;
244}
245
246const struct file_operations v9fs_dir_operations = {
247 .read = generic_read_dir,
248 .llseek = generic_file_llseek,
249 .iterate_shared = v9fs_dir_readdir,
250 .open = v9fs_file_open,
251 .release = v9fs_dir_release,
252};
253
254const struct file_operations v9fs_dir_operations_dotl = {
255 .read = generic_read_dir,
256 .llseek = generic_file_llseek,
257 .iterate_shared = v9fs_dir_readdir_dotl,
258 .open = v9fs_file_open,
259 .release = v9fs_dir_release,
260 .fsync = v9fs_file_fsync_dotl,
261};
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 p9_client_clunk(fid);
215 return 0;
216}
217
218const struct file_operations v9fs_dir_operations = {
219 .read = generic_read_dir,
220 .llseek = generic_file_llseek,
221 .iterate_shared = v9fs_dir_readdir,
222 .open = v9fs_file_open,
223 .release = v9fs_dir_release,
224};
225
226const struct file_operations v9fs_dir_operations_dotl = {
227 .read = generic_read_dir,
228 .llseek = generic_file_llseek,
229 .iterate_shared = v9fs_dir_readdir_dotl,
230 .open = v9fs_file_open,
231 .release = v9fs_dir_release,
232 .fsync = v9fs_file_fsync_dotl,
233};