1 /*-
2 * Copyright (c) 2017 Juniper Networks, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 */
26 /*-
27 * 9P filesystem subroutines. This file consists of all the Non VFS subroutines.
28 * It contains all of the functions related to the driver submission which form
29 * the upper layer i.e, p9fs driver. This will interact with the client to make
30 * sure we have correct API calls in the header.
31 */
32
33 #include <sys/cdefs.h>
34 #include <sys/systm.h>
35 #include <sys/limits.h>
36 #include <sys/mount.h>
37 #include <sys/sysctl.h>
38 #include <sys/vnode.h>
39
40 #include "p9fs_proto.h"
41
42 #include <fs/p9fs/p9_client.h>
43 #include <fs/p9fs/p9_debug.h>
44 #include <fs/p9fs/p9_protocol.h>
45 #include <fs/p9fs/p9fs.h>
46
47 int
p9fs_proto_dotl(struct p9fs_session * vses)48 p9fs_proto_dotl(struct p9fs_session *vses)
49 {
50
51 return (vses->flags & P9FS_PROTO_2000L);
52 }
53
54 /* Initialize a p9fs session */
55 struct p9_fid *
p9fs_init_session(struct mount * mp,int * error)56 p9fs_init_session(struct mount *mp, int *error)
57 {
58 struct p9fs_session *vses;
59 struct p9fs_mount *virtmp;
60 struct p9_fid *fid;
61 char *access;
62
63 virtmp = VFSTOP9(mp);
64 vses = &virtmp->p9fs_session;
65 vses->uid = P9_NONUNAME;
66 vses->uname = P9_DEFUNAME;
67 vses->aname = P9_DEFANAME;
68
69 /*
70 * Create the client structure. Call into the driver to create
71 * driver structures for the actual IO transfer.
72 */
73 vses->clnt = p9_client_create(mp, error, virtmp->mount_tag);
74
75 if (vses->clnt == NULL) {
76 P9_DEBUG(ERROR, "%s: p9_client_create failed\n", __func__);
77 return (NULL);
78 }
79 /*
80 * Find the client version and cache the copy. We will use this copy
81 * throughout FS layer.
82 */
83 if (p9_is_proto_dotl(vses->clnt))
84 vses->flags |= P9FS_PROTO_2000L;
85 else if (p9_is_proto_dotu(vses->clnt))
86 vses->flags |= P9FS_PROTO_2000U;
87
88 /* Set the access mode */
89 access = vfs_getopts(mp->mnt_optnew, "access", error);
90 if (access == NULL)
91 vses->flags |= P9_ACCESS_USER;
92 else if (!strcmp(access, "any"))
93 vses->flags |= P9_ACCESS_ANY;
94 else if (!strcmp(access, "single"))
95 vses->flags |= P9_ACCESS_SINGLE;
96 else if (!strcmp(access, "user"))
97 vses->flags |= P9_ACCESS_USER;
98 else {
99 P9_DEBUG(ERROR, "%s: unknown access mode\n", __func__);
100 *error = EINVAL;
101 goto out;
102 }
103
104 *error = 0;
105 /* Attach with the backend host*/
106 fid = p9_client_attach(vses->clnt, NULL, vses->uname, P9_NONUNAME,
107 vses->aname, error);
108 vses->mnt_fid = fid;
109
110 if (*error != 0) {
111 P9_DEBUG(ERROR, "%s: attach failed: %d\n", __func__, *error);
112 goto out;
113 }
114 P9_DEBUG(SUBR, "%s: attach successful fid :%p\n", __func__, fid);
115 fid->uid = vses->uid;
116
117 /* initialize the node list for the session */
118 STAILQ_INIT(&vses->virt_node_list);
119 P9FS_LOCK_INIT(vses);
120
121 P9_DEBUG(SUBR, "%s: INIT session successful\n", __func__);
122
123 return (fid);
124 out:
125 p9_client_destroy(vses->clnt);
126 return (NULL);
127 }
128
129 /* Begin to terminate a session */
130 void
p9fs_prepare_to_close(struct mount * mp)131 p9fs_prepare_to_close(struct mount *mp)
132 {
133 struct p9fs_session *vses;
134 struct p9fs_mount *vmp;
135 struct p9fs_node *np, *pnp, *tmp;
136
137 vmp = VFSTOP9(mp);
138 vses = &vmp->p9fs_session;
139
140 /* break the node->parent references */
141 STAILQ_FOREACH_SAFE(np, &vses->virt_node_list, p9fs_node_next, tmp) {
142 if (np->parent && np->parent != np) {
143 pnp = np->parent;
144 np->parent = NULL;
145 vrele(P9FS_NTOV(pnp));
146 }
147 }
148
149 /* We are about to teardown, we dont allow anything other than clunk after this.*/
150 p9_client_begin_disconnect(vses->clnt);
151 }
152
153 /* Shutdown a session */
154 void
p9fs_complete_close(struct mount * mp)155 p9fs_complete_close(struct mount *mp)
156 {
157 struct p9fs_session *vses;
158 struct p9fs_mount *vmp;
159
160 vmp = VFSTOP9(mp);
161 vses = &vmp->p9fs_session;
162
163 /* Finish the close*/
164 p9_client_disconnect(vses->clnt);
165 }
166
167
168 /* Call from unmount. Close the session. */
169 void
p9fs_close_session(struct mount * mp)170 p9fs_close_session(struct mount *mp)
171 {
172 struct p9fs_session *vses;
173 struct p9fs_mount *vmp;
174
175 vmp = VFSTOP9(mp);
176 vses = &vmp->p9fs_session;
177
178 p9fs_complete_close(mp);
179 /* Clean up the clnt structure. */
180 p9_client_destroy(vses->clnt);
181 P9FS_LOCK_DESTROY(vses);
182 P9_DEBUG(SUBR, "%s: Clean close session .\n", __func__);
183 }
184
185 /*
186 * Remove all the fids of a particular type from a p9fs node
187 * as well as destroy/clunk them.
188 */
189 void
p9fs_fid_remove_all(struct p9fs_node * np,int leave_ofids)190 p9fs_fid_remove_all(struct p9fs_node *np, int leave_ofids)
191 {
192 struct p9_fid *fid, *tfid;
193
194 STAILQ_FOREACH_SAFE(fid, &np->vfid_list, fid_next, tfid) {
195 STAILQ_REMOVE(&np->vfid_list, fid, p9_fid, fid_next);
196 p9_client_clunk(fid);
197 }
198
199 if (!leave_ofids) {
200 STAILQ_FOREACH_SAFE(fid, &np->vofid_list, fid_next, tfid) {
201 STAILQ_REMOVE(&np->vofid_list, fid, p9_fid, fid_next);
202 p9_client_clunk(fid);
203 }
204 }
205 }
206
207
208 /* Remove a fid from its corresponding fid list */
209 void
p9fs_fid_remove(struct p9fs_node * np,struct p9_fid * fid,int fid_type)210 p9fs_fid_remove(struct p9fs_node *np, struct p9_fid *fid, int fid_type)
211 {
212
213 switch (fid_type) {
214 case VFID:
215 P9FS_VFID_LOCK(np);
216 STAILQ_REMOVE(&np->vfid_list, fid, p9_fid, fid_next);
217 P9FS_VFID_UNLOCK(np);
218 break;
219 case VOFID:
220 P9FS_VOFID_LOCK(np);
221 STAILQ_REMOVE(&np->vofid_list, fid, p9_fid, fid_next);
222 P9FS_VOFID_UNLOCK(np);
223 break;
224 }
225 }
226
227 /* Add a fid to the corresponding fid list */
228 void
p9fs_fid_add(struct p9fs_node * np,struct p9_fid * fid,int fid_type)229 p9fs_fid_add(struct p9fs_node *np, struct p9_fid *fid, int fid_type)
230 {
231
232 switch (fid_type) {
233 case VFID:
234 P9FS_VFID_LOCK(np);
235 STAILQ_INSERT_TAIL(&np->vfid_list, fid, fid_next);
236 P9FS_VFID_UNLOCK(np);
237 break;
238 case VOFID:
239 P9FS_VOFID_LOCK(np);
240 STAILQ_INSERT_TAIL(&np->vofid_list, fid, fid_next);
241 P9FS_VOFID_UNLOCK(np);
242 break;
243 }
244 }
245
246 /* Build the path from root to current directory */
247 static int
p9fs_get_full_path(struct p9fs_node * np,char *** names)248 p9fs_get_full_path(struct p9fs_node *np, char ***names)
249 {
250 int i, n;
251 struct p9fs_node *node;
252 char **wnames;
253
254 n = 0;
255 for (node = np ; (node != NULL) && !IS_ROOT(node) ; node = node->parent)
256 n++;
257
258 if (node == NULL)
259 return (0);
260
261 wnames = malloc(n * sizeof(char *), M_TEMP, M_ZERO|M_WAITOK);
262
263 for (i = n-1, node = np; i >= 0 ; i--, node = node->parent)
264 wnames[i] = node->inode.i_name;
265
266 *names = wnames;
267 return (n);
268 }
269
270 /*
271 * Return TRUE if this fid can be used for the requested mode.
272 */
273 static int
p9fs_compatible_mode(struct p9_fid * fid,int mode)274 p9fs_compatible_mode(struct p9_fid *fid, int mode)
275 {
276 /*
277 * Return TRUE for an exact match. For OREAD and OWRITE, allow
278 * existing ORDWR fids to match. Only check the low two bits
279 * of mode.
280 *
281 * TODO: figure out if this is correct for O_APPEND
282 */
283 int fid_mode = fid->mode & 3;
284 if (fid_mode == mode)
285 return (TRUE);
286 if (fid_mode == P9PROTO_ORDWR)
287 return (mode == P9PROTO_OREAD || mode == P9PROTO_OWRITE);
288 return (FALSE);
289 }
290
291 /*
292 * Retrieve fid structure corresponding to a particular
293 * uid and fid type for a p9fs node
294 */
295 static struct p9_fid *
p9fs_get_fid_from_uid(struct p9fs_node * np,uid_t uid,int fid_type,int mode)296 p9fs_get_fid_from_uid(struct p9fs_node *np, uid_t uid, int fid_type, int mode)
297 {
298 struct p9_fid *fid;
299
300 switch (fid_type) {
301 case VFID:
302 P9FS_VFID_LOCK(np);
303 STAILQ_FOREACH(fid, &np->vfid_list, fid_next) {
304 if (fid->uid == uid) {
305 P9FS_VFID_UNLOCK(np);
306 return (fid);
307 }
308 }
309 P9FS_VFID_UNLOCK(np);
310 break;
311 case VOFID:
312 P9FS_VOFID_LOCK(np);
313 STAILQ_FOREACH(fid, &np->vofid_list, fid_next) {
314 if (fid->uid == uid && p9fs_compatible_mode(fid, mode)) {
315 P9FS_VOFID_UNLOCK(np);
316 return (fid);
317 }
318 }
319 P9FS_VOFID_UNLOCK(np);
320 break;
321 }
322
323 return (NULL);
324 }
325
326 /*
327 * Function returns the fid sturcture for a file corresponding to current user id.
328 * First it searches in the fid list of the corresponding p9fs node.
329 * New fid will be created if not already present and added in the corresponding
330 * fid list in the p9fs node.
331 * If the user is not already attached then this will attach the user first
332 * and then create a new fid for this particular file by doing dir walk.
333 */
334 struct p9_fid *
p9fs_get_fid(struct p9_client * clnt,struct p9fs_node * np,struct ucred * cred,int fid_type,int mode,int * error)335 p9fs_get_fid(struct p9_client *clnt, struct p9fs_node *np, struct ucred *cred,
336 int fid_type, int mode, int *error)
337 {
338 uid_t uid;
339 struct p9_fid *fid, *oldfid;
340 struct p9fs_node *root;
341 struct p9fs_session *vses;
342 int i, l, clone;
343 char **wnames = NULL;
344 uint16_t nwnames;
345
346 oldfid = NULL;
347 vses = np->p9fs_ses;
348
349 if (vses->flags & P9_ACCESS_ANY)
350 uid = vses->uid;
351 else if (cred)
352 uid = cred->cr_uid;
353 else
354 uid = 0;
355
356 /*
357 * Search for the fid in corresponding fid list.
358 * We should return NULL for VOFID if it is not present in the list.
359 * Because VOFID should have been created during the file open.
360 * If VFID is not present in the list then we should create one.
361 */
362 fid = p9fs_get_fid_from_uid(np, uid, fid_type, mode);
363 if (fid != NULL || fid_type == VOFID)
364 return (fid);
365
366 /* Check root if the user is attached */
367 root = &np->p9fs_ses->rnp;
368 fid = p9fs_get_fid_from_uid(root, uid, fid_type, mode);
369 if(fid == NULL) {
370 /* Attach the user */
371 fid = p9_client_attach(clnt, NULL, NULL, uid,
372 vses->aname, error);
373 if (*error != 0)
374 return (NULL);
375 p9fs_fid_add(root, fid, fid_type);
376 }
377
378 /* If we are looking for root then return it */
379 if (IS_ROOT(np))
380 return (fid);
381
382 /* Get full path from root to p9fs node */
383 nwnames = p9fs_get_full_path(np, &wnames);
384
385 /*
386 * Could not get full path.
387 * If p9fs node is not deleted, parent should exist.
388 */
389 KASSERT(nwnames != 0, ("%s: Directory of %s doesn't exist", __func__, np->inode.i_name));
390
391 clone = 1;
392 i = 0;
393 while (i < nwnames) {
394 l = MIN(nwnames - i, P9_MAXWELEM);
395
396 fid = p9_client_walk(fid, l, wnames, clone, error);
397 if (*error != 0) {
398 if (oldfid)
399 p9_client_clunk(oldfid);
400 fid = NULL;
401 goto bail_out;
402 }
403 oldfid = fid;
404 clone = 0;
405 i += l ;
406 }
407 p9fs_fid_add(np, fid, fid_type);
408 bail_out:
409 free(wnames, M_TEMP);
410 return (fid);
411 }
412