Commit | Line | Data |
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e69e7fe5 EVH |
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 | |
42e8c509 EVH |
10 | * it under the terms of the GNU General Public License version 2 |
11 | * as published by the Free Software Foundation. | |
e69e7fe5 EVH |
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> | |
914e2637 | 32 | #include <linux/sched.h> |
e69e7fe5 EVH |
33 | #include <linux/inet.h> |
34 | #include <linux/idr.h> | |
5a0e3ad6 | 35 | #include <linux/slab.h> |
bd238fb4 LI |
36 | #include <net/9p/9p.h> |
37 | #include <net/9p/client.h> | |
e69e7fe5 | 38 | |
e69e7fe5 | 39 | #include "v9fs.h" |
531b1094 | 40 | #include "v9fs_vfs.h" |
e69e7fe5 EVH |
41 | #include "fid.h" |
42 | ||
3e2796a9 EVH |
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 | ||
54 | struct p9_rdir { | |
55 | struct mutex mutex; | |
56 | int head; | |
57 | int tail; | |
58 | uint8_t *buf; | |
59 | }; | |
60 | ||
e69e7fe5 EVH |
61 | /** |
62 | * dt_type - return file type | |
63 | * @mistat: mistat structure | |
64 | * | |
65 | */ | |
66 | ||
02da398b | 67 | static inline int dt_type(struct p9_wstat *mistat) |
e69e7fe5 EVH |
68 | { |
69 | unsigned long perm = mistat->mode; | |
70 | int rettype = DT_REG; | |
71 | ||
bd238fb4 | 72 | if (perm & P9_DMDIR) |
e69e7fe5 | 73 | rettype = DT_DIR; |
bd238fb4 | 74 | if (perm & P9_DMSYMLINK) |
e69e7fe5 EVH |
75 | rettype = DT_LNK; |
76 | ||
77 | return rettype; | |
78 | } | |
79 | ||
fae4528b AK |
80 | static 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 | ||
e69e7fe5 | 89 | /** |
7751bdb3 | 90 | * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir |
ee443996 | 91 | * @filp: opened file structure |
7751bdb3 | 92 | * @buflen: Length in bytes of buffer to allocate |
e69e7fe5 EVH |
93 | * |
94 | */ | |
95 | ||
7751bdb3 | 96 | static int v9fs_alloc_rdir_buf(struct file *filp, int buflen) |
e69e7fe5 | 97 | { |
3e2796a9 | 98 | struct p9_rdir *rdir; |
7751bdb3 SK |
99 | struct p9_fid *fid; |
100 | int err = 0; | |
bd238fb4 | 101 | |
bd238fb4 | 102 | fid = filp->private_data; |
3e2796a9 EVH |
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 | } | |
7751bdb3 SK |
121 | exit: |
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 | ||
133 | static 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; | |
3e2796a9 EVH |
151 | rdir = (struct p9_rdir *) fid->rdir; |
152 | ||
153 | err = mutex_lock_interruptible(&rdir->mutex); | |
85a770a8 DC |
154 | if (err) |
155 | return err; | |
3e2796a9 EVH |
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 | } | |
3e2796a9 | 166 | while (rdir->head < rdir->tail) { |
fae4528b | 167 | p9stat_init(&st); |
3e2796a9 | 168 | err = p9stat_read(rdir->buf + rdir->head, |
da7ddd32 | 169 | rdir->tail - rdir->head, &st, |
342fee1d | 170 | fid->clnt->proto_version); |
02da398b EVH |
171 | if (err) { |
172 | P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err); | |
06b55b46 | 173 | err = -EIO; |
02da398b | 174 | p9stat_free(&st); |
3e2796a9 | 175 | goto unlock_and_exit; |
06b55b46 | 176 | } |
3e2796a9 | 177 | reclen = st.size+2; |
06b55b46 | 178 | |
02da398b | 179 | over = filldir(dirent, st.name, strlen(st.name), |
06b55b46 EVH |
180 | filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st)); |
181 | ||
02da398b | 182 | p9stat_free(&st); |
06b55b46 EVH |
183 | |
184 | if (over) { | |
185 | err = 0; | |
3e2796a9 | 186 | goto unlock_and_exit; |
06b55b46 | 187 | } |
3e2796a9 EVH |
188 | rdir->head += reclen; |
189 | filp->f_pos += reclen; | |
06b55b46 | 190 | } |
e69e7fe5 EVH |
191 | } |
192 | ||
3e2796a9 EVH |
193 | unlock_and_exit: |
194 | mutex_unlock(&rdir->mutex); | |
195 | exit: | |
06b55b46 | 196 | return err; |
e69e7fe5 EVH |
197 | } |
198 | ||
7751bdb3 SK |
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 | */ | |
206 | static 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 | ||
275 | unlock_and_exit: | |
276 | mutex_unlock(&rdir->mutex); | |
277 | exit: | |
278 | return err; | |
279 | } | |
280 | ||
bd238fb4 | 281 | |
e69e7fe5 EVH |
282 | /** |
283 | * v9fs_dir_release - close a directory | |
284 | * @inode: inode of the directory | |
285 | * @filp: file pointer to a directory | |
286 | * | |
287 | */ | |
288 | ||
289 | int v9fs_dir_release(struct inode *inode, struct file *filp) | |
290 | { | |
bd238fb4 | 291 | struct p9_fid *fid; |
e69e7fe5 | 292 | |
bd238fb4 LI |
293 | fid = filp->private_data; |
294 | P9_DPRINTK(P9_DEBUG_VFS, | |
295 | "inode: %p filp: %p fid: %d\n", inode, filp, fid->fid); | |
28fd1298 | 296 | filemap_write_and_wait(inode->i_mapping); |
bd238fb4 | 297 | p9_client_clunk(fid); |
e69e7fe5 EVH |
298 | return 0; |
299 | } | |
300 | ||
4b6f5d20 | 301 | const struct file_operations v9fs_dir_operations = { |
e69e7fe5 | 302 | .read = generic_read_dir, |
59af1584 | 303 | .llseek = generic_file_llseek, |
e69e7fe5 EVH |
304 | .readdir = v9fs_dir_readdir, |
305 | .open = v9fs_file_open, | |
306 | .release = v9fs_dir_release, | |
307 | }; | |
9b6533c9 SK |
308 | |
309 | const struct file_operations v9fs_dir_operations_dotl = { | |
310 | .read = generic_read_dir, | |
311 | .llseek = generic_file_llseek, | |
7751bdb3 | 312 | .readdir = v9fs_dir_readdir_dotl, |
9b6533c9 SK |
313 | .open = v9fs_file_open, |
314 | .release = v9fs_dir_release, | |
315 | }; |