Merge tag 'pull-testing-gdbstub-plugins-gitdm-061022-3' of https://github.com/stsquad...
[qemu.git] / hw / 9pfs / cofs.c
1 /*
2 * 9p backend
3 *
4 * Copyright IBM, Corp. 2011
5 *
6 * Authors:
7 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
12 */
13
14 /*
15 * Not so fast! You might want to read the 9p developer docs first:
16 * https://wiki.qemu.org/Documentation/9p
17 */
18
19 #include "qemu/osdep.h"
20 #include "fsdev/qemu-fsdev.h"
21 #include "qemu/thread.h"
22 #include "qemu/coroutine.h"
23 #include "qemu/main-loop.h"
24 #include "coth.h"
25
26 static ssize_t __readlink(V9fsState *s, V9fsPath *path, V9fsString *buf)
27 {
28 ssize_t len, maxlen = PATH_MAX;
29
30 buf->data = g_malloc(PATH_MAX);
31 for (;;) {
32 len = s->ops->readlink(&s->ctx, path, buf->data, maxlen);
33 if (len < 0) {
34 g_free(buf->data);
35 buf->data = NULL;
36 buf->size = 0;
37 break;
38 } else if (len == maxlen) {
39 /*
40 * We dodn't have space to put the NULL or we have more
41 * to read. Increase the size and try again
42 */
43 maxlen *= 2;
44 g_free(buf->data);
45 buf->data = g_malloc(maxlen);
46 continue;
47 }
48 /*
49 * Null terminate the readlink output
50 */
51 buf->data[len] = '\0';
52 buf->size = len;
53 break;
54 }
55 return len;
56 }
57
58 int coroutine_fn v9fs_co_readlink(V9fsPDU *pdu, V9fsPath *path, V9fsString *buf)
59 {
60 int err;
61 V9fsState *s = pdu->s;
62
63 if (v9fs_request_cancelled(pdu)) {
64 return -EINTR;
65 }
66 v9fs_path_read_lock(s);
67 v9fs_co_run_in_worker(
68 {
69 err = __readlink(s, path, buf);
70 if (err < 0) {
71 err = -errno;
72 }
73 });
74 v9fs_path_unlock(s);
75 return err;
76 }
77
78 int coroutine_fn v9fs_co_statfs(V9fsPDU *pdu, V9fsPath *path,
79 struct statfs *stbuf)
80 {
81 int err;
82 V9fsState *s = pdu->s;
83
84 if (v9fs_request_cancelled(pdu)) {
85 return -EINTR;
86 }
87 v9fs_path_read_lock(s);
88 v9fs_co_run_in_worker(
89 {
90 err = s->ops->statfs(&s->ctx, path, stbuf);
91 if (err < 0) {
92 err = -errno;
93 }
94 });
95 v9fs_path_unlock(s);
96 return err;
97 }
98
99 int coroutine_fn v9fs_co_chmod(V9fsPDU *pdu, V9fsPath *path, mode_t mode)
100 {
101 int err;
102 FsCred cred;
103 V9fsState *s = pdu->s;
104
105 if (v9fs_request_cancelled(pdu)) {
106 return -EINTR;
107 }
108 cred_init(&cred);
109 cred.fc_mode = mode;
110 v9fs_path_read_lock(s);
111 v9fs_co_run_in_worker(
112 {
113 err = s->ops->chmod(&s->ctx, path, &cred);
114 if (err < 0) {
115 err = -errno;
116 }
117 });
118 v9fs_path_unlock(s);
119 return err;
120 }
121
122 int coroutine_fn v9fs_co_utimensat(V9fsPDU *pdu, V9fsPath *path,
123 struct timespec times[2])
124 {
125 int err;
126 V9fsState *s = pdu->s;
127
128 if (v9fs_request_cancelled(pdu)) {
129 return -EINTR;
130 }
131 v9fs_path_read_lock(s);
132 v9fs_co_run_in_worker(
133 {
134 err = s->ops->utimensat(&s->ctx, path, times);
135 if (err < 0) {
136 err = -errno;
137 }
138 });
139 v9fs_path_unlock(s);
140 return err;
141 }
142
143 int coroutine_fn v9fs_co_chown(V9fsPDU *pdu, V9fsPath *path, uid_t uid,
144 gid_t gid)
145 {
146 int err;
147 FsCred cred;
148 V9fsState *s = pdu->s;
149
150 if (v9fs_request_cancelled(pdu)) {
151 return -EINTR;
152 }
153 cred_init(&cred);
154 cred.fc_uid = uid;
155 cred.fc_gid = gid;
156 v9fs_path_read_lock(s);
157 v9fs_co_run_in_worker(
158 {
159 err = s->ops->chown(&s->ctx, path, &cred);
160 if (err < 0) {
161 err = -errno;
162 }
163 });
164 v9fs_path_unlock(s);
165 return err;
166 }
167
168 int coroutine_fn v9fs_co_truncate(V9fsPDU *pdu, V9fsPath *path, off_t size)
169 {
170 int err;
171 V9fsState *s = pdu->s;
172
173 if (v9fs_request_cancelled(pdu)) {
174 return -EINTR;
175 }
176 v9fs_path_read_lock(s);
177 v9fs_co_run_in_worker(
178 {
179 err = s->ops->truncate(&s->ctx, path, size);
180 if (err < 0) {
181 err = -errno;
182 }
183 });
184 v9fs_path_unlock(s);
185 return err;
186 }
187
188 int coroutine_fn v9fs_co_mknod(V9fsPDU *pdu, V9fsFidState *fidp,
189 V9fsString *name, uid_t uid, gid_t gid,
190 dev_t dev, mode_t mode, struct stat *stbuf)
191 {
192 int err;
193 V9fsPath path;
194 FsCred cred;
195 V9fsState *s = pdu->s;
196
197 if (v9fs_request_cancelled(pdu)) {
198 return -EINTR;
199 }
200 cred_init(&cred);
201 cred.fc_uid = uid;
202 cred.fc_gid = gid;
203 cred.fc_mode = mode;
204 cred.fc_rdev = dev;
205 v9fs_path_read_lock(s);
206 v9fs_co_run_in_worker(
207 {
208 err = s->ops->mknod(&s->ctx, &fidp->path, name->data, &cred);
209 if (err < 0) {
210 err = -errno;
211 } else {
212 v9fs_path_init(&path);
213 err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
214 if (!err) {
215 err = s->ops->lstat(&s->ctx, &path, stbuf);
216 if (err < 0) {
217 err = -errno;
218 }
219 }
220 v9fs_path_free(&path);
221 }
222 });
223 v9fs_path_unlock(s);
224 return err;
225 }
226
227 /* Only works with path name based fid */
228 int coroutine_fn v9fs_co_remove(V9fsPDU *pdu, V9fsPath *path)
229 {
230 int err;
231 V9fsState *s = pdu->s;
232
233 if (v9fs_request_cancelled(pdu)) {
234 return -EINTR;
235 }
236 v9fs_path_read_lock(s);
237 v9fs_co_run_in_worker(
238 {
239 err = s->ops->remove(&s->ctx, path->data);
240 if (err < 0) {
241 err = -errno;
242 }
243 });
244 v9fs_path_unlock(s);
245 return err;
246 }
247
248 int coroutine_fn v9fs_co_unlinkat(V9fsPDU *pdu, V9fsPath *path,
249 V9fsString *name, int flags)
250 {
251 int err;
252 V9fsState *s = pdu->s;
253
254 if (v9fs_request_cancelled(pdu)) {
255 return -EINTR;
256 }
257 v9fs_path_read_lock(s);
258 v9fs_co_run_in_worker(
259 {
260 err = s->ops->unlinkat(&s->ctx, path, name->data, flags);
261 if (err < 0) {
262 err = -errno;
263 }
264 });
265 v9fs_path_unlock(s);
266 return err;
267 }
268
269 /* Only work with path name based fid */
270 int coroutine_fn v9fs_co_rename(V9fsPDU *pdu, V9fsPath *oldpath,
271 V9fsPath *newpath)
272 {
273 int err;
274 V9fsState *s = pdu->s;
275
276 if (v9fs_request_cancelled(pdu)) {
277 return -EINTR;
278 }
279 v9fs_co_run_in_worker(
280 {
281 err = s->ops->rename(&s->ctx, oldpath->data, newpath->data);
282 if (err < 0) {
283 err = -errno;
284 }
285 });
286 return err;
287 }
288
289 int coroutine_fn v9fs_co_renameat(V9fsPDU *pdu, V9fsPath *olddirpath,
290 V9fsString *oldname, V9fsPath *newdirpath,
291 V9fsString *newname)
292 {
293 int err;
294 V9fsState *s = pdu->s;
295
296 if (v9fs_request_cancelled(pdu)) {
297 return -EINTR;
298 }
299 v9fs_co_run_in_worker(
300 {
301 err = s->ops->renameat(&s->ctx, olddirpath, oldname->data,
302 newdirpath, newname->data);
303 if (err < 0) {
304 err = -errno;
305 }
306 });
307 return err;
308 }
309
310 int coroutine_fn v9fs_co_symlink(V9fsPDU *pdu, V9fsFidState *dfidp,
311 V9fsString *name, const char *oldpath,
312 gid_t gid, struct stat *stbuf)
313 {
314 int err;
315 FsCred cred;
316 V9fsPath path;
317 V9fsState *s = pdu->s;
318
319 if (v9fs_request_cancelled(pdu)) {
320 return -EINTR;
321 }
322 cred_init(&cred);
323 cred.fc_uid = dfidp->uid;
324 cred.fc_gid = gid;
325 cred.fc_mode = 0777;
326 v9fs_path_read_lock(s);
327 v9fs_co_run_in_worker(
328 {
329 err = s->ops->symlink(&s->ctx, oldpath, &dfidp->path,
330 name->data, &cred);
331 if (err < 0) {
332 err = -errno;
333 } else {
334 v9fs_path_init(&path);
335 err = v9fs_name_to_path(s, &dfidp->path, name->data, &path);
336 if (!err) {
337 err = s->ops->lstat(&s->ctx, &path, stbuf);
338 if (err < 0) {
339 err = -errno;
340 }
341 }
342 v9fs_path_free(&path);
343 }
344 });
345 v9fs_path_unlock(s);
346 return err;
347 }
348
349 /*
350 * For path name based fid we don't block. So we can
351 * directly call the fs driver ops.
352 */
353 int coroutine_fn v9fs_co_name_to_path(V9fsPDU *pdu, V9fsPath *dirpath,
354 const char *name, V9fsPath *path)
355 {
356 int err;
357 V9fsState *s = pdu->s;
358
359 if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
360 err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
361 if (err < 0) {
362 err = -errno;
363 }
364 } else {
365 if (v9fs_request_cancelled(pdu)) {
366 return -EINTR;
367 }
368 v9fs_co_run_in_worker(
369 {
370 err = s->ops->name_to_path(&s->ctx, dirpath, name, path);
371 if (err < 0) {
372 err = -errno;
373 }
374 });
375 }
376 return err;
377 }