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 #include "qemu/osdep.h"
15 #include "fsdev/qemu-fsdev.h"
16 #include "qemu/thread.h"
17 #include "qemu/coroutine.h"
18 #include "qemu/main-loop.h"
19 #include "coth.h"
20
v9fs_co_st_gen(V9fsPDU * pdu,V9fsPath * path,mode_t st_mode,V9fsStatDotl * v9stat)21 int coroutine_fn v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
22 V9fsStatDotl *v9stat)
23 {
24 int err = 0;
25 V9fsState *s = pdu->s;
26
27 if (v9fs_request_cancelled(pdu)) {
28 return -EINTR;
29 }
30 if (s->ctx.exops.get_st_gen) {
31 v9fs_path_read_lock(s);
32 v9fs_co_run_in_worker(
33 {
34 err = s->ctx.exops.get_st_gen(&s->ctx, path, st_mode,
35 &v9stat->st_gen);
36 if (err < 0) {
37 err = -errno;
38 }
39 });
40 v9fs_path_unlock(s);
41 }
42 return err;
43 }
44
v9fs_co_lstat(V9fsPDU * pdu,V9fsPath * path,struct stat * stbuf)45 int coroutine_fn v9fs_co_lstat(V9fsPDU *pdu, V9fsPath *path, struct stat *stbuf)
46 {
47 int err;
48 V9fsState *s = pdu->s;
49
50 if (v9fs_request_cancelled(pdu)) {
51 return -EINTR;
52 }
53 v9fs_path_read_lock(s);
54 v9fs_co_run_in_worker(
55 {
56 err = s->ops->lstat(&s->ctx, path, stbuf);
57 if (err < 0) {
58 err = -errno;
59 }
60 });
61 v9fs_path_unlock(s);
62 return err;
63 }
64
v9fs_co_fstat(V9fsPDU * pdu,V9fsFidState * fidp,struct stat * stbuf)65 int coroutine_fn v9fs_co_fstat(V9fsPDU *pdu, V9fsFidState *fidp,
66 struct stat *stbuf)
67 {
68 int err;
69 V9fsState *s = pdu->s;
70
71 if (v9fs_request_cancelled(pdu)) {
72 return -EINTR;
73 }
74 v9fs_co_run_in_worker(
75 {
76 err = s->ops->fstat(&s->ctx, fidp->fid_type, &fidp->fs, stbuf);
77 if (err < 0) {
78 err = -errno;
79 }
80 });
81 /*
82 * Some FS driver (local:mapped-file) can't support fetching attributes
83 * using file descriptor. Use Path name in that case.
84 */
85 if (err == -EOPNOTSUPP) {
86 err = v9fs_co_lstat(pdu, &fidp->path, stbuf);
87 if (err == -ENOENT) {
88 /*
89 * fstat on an unlinked file. Work with partial results
90 * returned from s->ops->fstat
91 */
92 err = 0;
93 }
94 }
95 return err;
96 }
97
v9fs_co_open(V9fsPDU * pdu,V9fsFidState * fidp,int flags)98 int coroutine_fn v9fs_co_open(V9fsPDU *pdu, V9fsFidState *fidp, int flags)
99 {
100 int err;
101 V9fsState *s = pdu->s;
102
103 if (v9fs_request_cancelled(pdu)) {
104 return -EINTR;
105 }
106 v9fs_path_read_lock(s);
107 v9fs_co_run_in_worker(
108 {
109 err = s->ops->open(&s->ctx, &fidp->path, flags, &fidp->fs);
110 if (err == -1) {
111 err = -errno;
112 } else {
113 err = 0;
114 }
115 });
116 v9fs_path_unlock(s);
117 if (!err) {
118 total_open_fd++;
119 if (total_open_fd > open_fd_hw) {
120 v9fs_reclaim_fd(pdu);
121 }
122 }
123 return err;
124 }
125
v9fs_co_open2(V9fsPDU * pdu,V9fsFidState * fidp,V9fsString * name,gid_t gid,int flags,int mode,struct stat * stbuf)126 int coroutine_fn v9fs_co_open2(V9fsPDU *pdu, V9fsFidState *fidp,
127 V9fsString *name, gid_t gid, int flags, int mode,
128 struct stat *stbuf)
129 {
130 int err;
131 FsCred cred;
132 V9fsPath path;
133 V9fsState *s = pdu->s;
134
135 if (v9fs_request_cancelled(pdu)) {
136 return -EINTR;
137 }
138 cred_init(&cred);
139 cred.fc_mode = mode & 07777;
140 cred.fc_uid = fidp->uid;
141 cred.fc_gid = gid;
142 /*
143 * Hold the directory fid lock so that directory path name
144 * don't change. Take the write lock to be sure this fid
145 * cannot be used by another operation.
146 */
147 v9fs_path_write_lock(s);
148 v9fs_co_run_in_worker(
149 {
150 err = s->ops->open2(&s->ctx, &fidp->path,
151 name->data, flags, &cred, &fidp->fs);
152 if (err < 0) {
153 err = -errno;
154 } else {
155 v9fs_path_init(&path);
156 err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
157 if (!err) {
158 err = s->ops->lstat(&s->ctx, &path, stbuf);
159 if (err < 0) {
160 err = -errno;
161 s->ops->close(&s->ctx, &fidp->fs);
162 } else {
163 v9fs_path_copy(&fidp->path, &path);
164 }
165 } else {
166 s->ops->close(&s->ctx, &fidp->fs);
167 }
168 v9fs_path_free(&path);
169 }
170 });
171 v9fs_path_unlock(s);
172 if (!err) {
173 total_open_fd++;
174 if (total_open_fd > open_fd_hw) {
175 v9fs_reclaim_fd(pdu);
176 }
177 }
178 return err;
179 }
180
v9fs_co_close(V9fsPDU * pdu,V9fsFidOpenState * fs)181 int coroutine_fn v9fs_co_close(V9fsPDU *pdu, V9fsFidOpenState *fs)
182 {
183 int err;
184 V9fsState *s = pdu->s;
185
186 if (v9fs_request_cancelled(pdu)) {
187 return -EINTR;
188 }
189 v9fs_co_run_in_worker(
190 {
191 err = s->ops->close(&s->ctx, fs);
192 if (err < 0) {
193 err = -errno;
194 }
195 });
196 if (!err) {
197 total_open_fd--;
198 }
199 return err;
200 }
201
v9fs_co_fsync(V9fsPDU * pdu,V9fsFidState * fidp,int datasync)202 int coroutine_fn v9fs_co_fsync(V9fsPDU *pdu, V9fsFidState *fidp, int datasync)
203 {
204 int err;
205 V9fsState *s = pdu->s;
206
207 if (v9fs_request_cancelled(pdu)) {
208 return -EINTR;
209 }
210 v9fs_co_run_in_worker(
211 {
212 err = s->ops->fsync(&s->ctx, fidp->fid_type, &fidp->fs, datasync);
213 if (err < 0) {
214 err = -errno;
215 }
216 });
217 return err;
218 }
219
v9fs_co_link(V9fsPDU * pdu,V9fsFidState * oldfid,V9fsFidState * newdirfid,V9fsString * name)220 int coroutine_fn v9fs_co_link(V9fsPDU *pdu, V9fsFidState *oldfid,
221 V9fsFidState *newdirfid, V9fsString *name)
222 {
223 int err;
224 V9fsState *s = pdu->s;
225
226 if (v9fs_request_cancelled(pdu)) {
227 return -EINTR;
228 }
229 v9fs_path_read_lock(s);
230 v9fs_co_run_in_worker(
231 {
232 err = s->ops->link(&s->ctx, &oldfid->path,
233 &newdirfid->path, name->data);
234 if (err < 0) {
235 err = -errno;
236 }
237 });
238 v9fs_path_unlock(s);
239 return err;
240 }
241
v9fs_co_pwritev(V9fsPDU * pdu,V9fsFidState * fidp,struct iovec * iov,int iovcnt,int64_t offset)242 int coroutine_fn v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
243 struct iovec *iov, int iovcnt, int64_t offset)
244 {
245 int err;
246 V9fsState *s = pdu->s;
247
248 if (v9fs_request_cancelled(pdu)) {
249 return -EINTR;
250 }
251 fsdev_co_throttle_request(s->ctx.fst, true, iov, iovcnt);
252 v9fs_co_run_in_worker(
253 {
254 err = s->ops->pwritev(&s->ctx, &fidp->fs, iov, iovcnt, offset);
255 if (err < 0) {
256 err = -errno;
257 }
258 });
259 return err;
260 }
261
v9fs_co_preadv(V9fsPDU * pdu,V9fsFidState * fidp,struct iovec * iov,int iovcnt,int64_t offset)262 int coroutine_fn v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
263 struct iovec *iov, int iovcnt, int64_t offset)
264 {
265 int err;
266 V9fsState *s = pdu->s;
267
268 if (v9fs_request_cancelled(pdu)) {
269 return -EINTR;
270 }
271 fsdev_co_throttle_request(s->ctx.fst, false, iov, iovcnt);
272 v9fs_co_run_in_worker(
273 {
274 err = s->ops->preadv(&s->ctx, &fidp->fs, iov, iovcnt, offset);
275 if (err < 0) {
276 err = -errno;
277 }
278 });
279 return err;
280 }
281