xref: /illumos-gate/usr/src/uts/common/fs/portfs/port_vnops.c (revision 581cede61ac9c14d8d4ea452562a567189eead78)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/vnode.h>
29 #include <sys/vfs_opreg.h>
30 #include <sys/kmem.h>
31 #include <fs/fs_subr.h>
32 #include <sys/proc.h>
33 #include <sys/kstat.h>
34 #include <sys/port_impl.h>
35 
36 /* local functions */
37 static int port_open(struct vnode **, int, cred_t *, caller_context_t *);
38 static int port_close(struct vnode *, int, int, offset_t, cred_t *,
39 	caller_context_t *);
40 static int port_getattr(struct vnode *, struct vattr *, int, cred_t *,
41 	caller_context_t *);
42 static int port_access(struct vnode *, int, int, cred_t *, caller_context_t *);
43 static int port_realvp(vnode_t *, vnode_t **, caller_context_t *);
44 static int port_poll(vnode_t *, short, int, short *, struct pollhead **,
45 	caller_context_t *);
46 static void port_inactive(struct vnode *, cred_t *, caller_context_t *);
47 
48 const fs_operation_def_t port_vnodeops_template[] = {
49 	VOPNAME_OPEN,		{ .vop_open = port_open },
50 	VOPNAME_CLOSE,		{ .vop_close = port_close },
51 	VOPNAME_GETATTR,	{ .vop_getattr = port_getattr },
52 	VOPNAME_ACCESS,		{ .vop_access = port_access },
53 	VOPNAME_INACTIVE,	{ .vop_inactive = port_inactive },
54 	VOPNAME_FRLOCK,		{ .error = fs_error },
55 	VOPNAME_REALVP,		{ .vop_realvp = port_realvp },
56 	VOPNAME_POLL,		{ .vop_poll = port_poll },
57 	VOPNAME_PATHCONF,	{ .error = fs_error },
58 	VOPNAME_DISPOSE,	{ .error = fs_error },
59 	VOPNAME_GETSECATTR,	{ .error = fs_error },
60 	VOPNAME_SHRLOCK,	{ .error = fs_error },
61 	NULL,			NULL
62 };
63 
64 /* ARGSUSED */
65 static int
66 port_open(struct vnode **vpp, int flag, cred_t *cr, caller_context_t *ct)
67 {
68 	return (0);
69 }
70 
71 /*
72  * port_discard_events() scans the port event queue for events owned
73  * by current proc. Non-shareable events will be discarded, all other
74  * events remain in the event queue.
75  */
76 void
77 port_discard_events(port_queue_t *portq)
78 {
79 	port_kevent_t	*kevp;
80 	pid_t		pid = curproc->p_pid;
81 
82 	/*
83 	 * The call to port_block() is required to avoid interaction
84 	 * with other threads in port_get(n).
85 	 */
86 	mutex_enter(&portq->portq_mutex);
87 	port_block(portq);
88 	port_push_eventq(portq);	/* empty temporary queue */
89 	kevp = list_head(&portq->portq_list);
90 	while (kevp) {
91 		if (kevp->portkev_pid == pid) {
92 			/* own event, check if it is shareable */
93 			if (kevp->portkev_flags & PORT_KEV_NOSHARE)
94 				kevp->portkev_flags |= PORT_KEV_FREE;
95 		}
96 		kevp = list_next(&portq->portq_list, kevp);
97 	}
98 	port_unblock(portq);
99 	mutex_exit(&portq->portq_mutex);
100 }
101 
102 /*
103  * Called from port_close().
104  * Free all kernel events structures which are still in the event queue.
105  */
106 static void
107 port_close_events(port_queue_t *portq)
108 {
109 	port_kevent_t	*pkevp;
110 	int		events;		/* ignore events */
111 
112 	mutex_enter(&portq->portq_mutex);
113 	while (pkevp = list_head(&portq->portq_list)) {
114 		portq->portq_nent--;
115 		list_remove(&portq->portq_list, pkevp);
116 		if (pkevp->portkev_callback) {
117 			(void) (*pkevp->portkev_callback)(pkevp->portkev_arg,
118 			    &events, pkevp->portkev_pid, PORT_CALLBACK_CLOSE,
119 			    pkevp);
120 		}
121 		mutex_exit(&portq->portq_mutex);
122 		port_free_event_local(pkevp, 0);
123 		mutex_enter(&portq->portq_mutex);
124 	}
125 
126 	/*
127 	 * Wait for any thread in pollwakeup(), accessing this port to
128 	 * finish.
129 	 */
130 	while (portq->portq_flags & PORTQ_POLLWK_PEND) {
131 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
132 	}
133 	mutex_exit(&portq->portq_mutex);
134 }
135 
136 /*
137  * The port_close() function is called from standard close(2) when
138  * the file descriptor is of type S_IFPORT/VPORT.
139  * Port file descriptors behave like standard file descriptors. It means,
140  * the port file/vnode is only destroyed on last close.
141  * If the reference counter is > 1 then
142  * - sources associated with the port will be notified about the close,
143  * - objects associated with the port will be dissociated,
144  * - pending and delivered events will be discarded.
145  * On last close all references and caches will be removed. The vnode itself
146  * will be destroyed with VOP_RELE().
147  */
148 /* ARGSUSED */
149 static int
150 port_close(struct vnode *vp, int flag, int count, offset_t offset, cred_t *cr,
151     caller_context_t *ct)
152 {
153 	port_t		*pp;
154 	port_queue_t	*portq;
155 	port_source_t	*ps;
156 	port_source_t	*ps_next;
157 	int		source;
158 
159 	pp = VTOEP(vp);
160 	mutex_enter(&pp->port_mutex);
161 	if (pp->port_flags & PORT_CLOSED) {
162 		mutex_exit(&pp->port_mutex);
163 		return (0);
164 	}
165 	mutex_exit(&pp->port_mutex);
166 
167 	portq = &pp->port_queue;
168 	if (count > 1) {
169 		/*
170 		 * It is not the last close.
171 		 * Remove/free all event resources owned by the current proc
172 		 * First notify all with the port associated sources about the
173 		 * close(2). The last argument of the close callback function
174 		 * advises the source about the type of of the close.
175 		 * If the port was set in alert mode by the curren process then
176 		 * remove the alert mode.
177 		 */
178 
179 		/* check alert mode of the port */
180 		mutex_enter(&portq->portq_mutex);
181 		if ((portq->portq_flags & PORTQ_ALERT) &&
182 		    (portq->portq_alert.portal_pid == curproc->p_pid))
183 			portq->portq_flags &= ~PORTQ_ALERT;
184 		mutex_exit(&portq->portq_mutex);
185 
186 		/* notify all event sources about port_close() */
187 		mutex_enter(&portq->portq_source_mutex);
188 		for (source = 0; source < PORT_SCACHE_SIZE; source++) {
189 			ps = portq->portq_scache[PORT_SHASH(source)];
190 			for (; ps != NULL; ps = ps->portsrc_next) {
191 				if (ps->portsrc_close != NULL)
192 					(*ps->portsrc_close)
193 					    (ps->portsrc_closearg, pp->port_fd,
194 					    curproc->p_pid, 0);
195 			}
196 		}
197 		mutex_exit(&portq->portq_source_mutex);
198 		port_discard_events(&pp->port_queue);
199 		return (0);
200 	}
201 
202 	/*
203 	 * We are executing the last close of the port -> discard everything
204 	 * Make sure that all threads/processes accessing this port leave
205 	 * the kernel immediately.
206 	 */
207 
208 	mutex_enter(&portq->portq_mutex);
209 	portq->portq_flags |= PORTQ_CLOSE;
210 	while (portq->portq_thrcnt > 0) {
211 		if (portq->portq_thread != NULL)
212 			cv_signal(&portq->portq_thread->portget_cv);
213 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
214 	}
215 	mutex_exit(&portq->portq_mutex);
216 
217 	/*
218 	 * Send "last close" message to associated sources.
219 	 * - new event allocation requests are being denied since uf_file entry
220 	 *   was set to NULL in closeandsetf().
221 	 * - all still allocated event structures must be returned to the
222 	 *   port immediately:
223 	 *	- call port_free_event(*event) or
224 	 *	- call port_send_event(*event) to complete event operations
225 	 *	  which need activities in a dedicated process environment.
226 	 * The port_close() function waits until all allocated event structures
227 	 * are delivered back to the port.
228 	 */
229 
230 	mutex_enter(&portq->portq_source_mutex);
231 	for (source = 0; source < PORT_SCACHE_SIZE; source++) {
232 		ps = portq->portq_scache[PORT_SHASH(source)];
233 		for (; ps != NULL; ps = ps_next) {
234 			ps_next = ps->portsrc_next;
235 			if (ps->portsrc_close != NULL)
236 				(*ps->portsrc_close)(ps->portsrc_closearg,
237 				    pp->port_fd, curproc->p_pid, 1);
238 			kmem_free(ps, sizeof (port_source_t));
239 		}
240 	}
241 	kmem_free(portq->portq_scache,
242 	    PORT_SCACHE_SIZE * sizeof (port_source_t *));
243 	portq->portq_scache = NULL;
244 	mutex_exit(&portq->portq_source_mutex);
245 
246 	mutex_enter(&portq->portq_mutex);
247 	/* Wait for outstanding events */
248 	while (pp->port_curr > portq->portq_nent)
249 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
250 	mutex_exit(&portq->portq_mutex);
251 
252 	/*
253 	 * If PORT_SOURCE_FD objects were not associated with the port then
254 	 * it is necessary to free the port_fdcache structure here.
255 	 */
256 
257 	if (portq->portq_pcp != NULL) {
258 		mutex_destroy(&portq->portq_pcp->pc_lock);
259 		kmem_free(portq->portq_pcp, sizeof (port_fdcache_t));
260 		portq->portq_pcp = NULL;
261 	}
262 
263 	/*
264 	 * Now all events are passed back to the port,
265 	 * discard remaining events in the port queue
266 	 */
267 
268 	port_close_events(portq);
269 	return (0);
270 }
271 
272 /*
273  * The port_poll() function is the VOP_POLL() entry of event ports.
274  * Event ports return:
275  * POLLIN  : events are available in the event queue
276  * POLLOUT : event queue can still accept events
277  */
278 /*ARGSUSED*/
279 static int
280 port_poll(vnode_t *vp, short events, int anyyet, short *reventsp,
281     struct pollhead **phpp, caller_context_t *ct)
282 {
283 	port_t		*pp;
284 	port_queue_t	*portq;
285 	short		levents;
286 
287 	pp = VTOEP(vp);
288 	portq = &pp->port_queue;
289 	levents = 0;
290 	mutex_enter(&portq->portq_mutex);
291 	if (portq->portq_nent)
292 		levents = POLLIN;
293 	if (pp->port_curr < pp->port_max_events)
294 		levents |= POLLOUT;
295 	levents &= events;
296 	*reventsp = levents;
297 	if (levents == 0) {
298 		if (!anyyet) {
299 			*phpp = &pp->port_pollhd;
300 			portq->portq_flags |=
301 			    events & POLLIN ? PORTQ_POLLIN : 0;
302 			portq->portq_flags |=
303 			    events & POLLOUT ? PORTQ_POLLOUT : 0;
304 		}
305 	}
306 	mutex_exit(&portq->portq_mutex);
307 	return (0);
308 }
309 
310 
311 /* ARGSUSED */
312 static int
313 port_getattr(struct vnode *vp, struct vattr *vap, int flags, cred_t *cr,
314     caller_context_t *ct)
315 {
316 	port_t	*pp;
317 	extern dev_t portdev;
318 
319 	pp = VTOEP(vp);
320 
321 	vap->va_type = vp->v_type;	/* vnode type (for create) */
322 	vap->va_mode = 0;		/* file access mode */
323 	vap->va_uid = pp->port_uid;	/* owner user id */
324 	vap->va_gid = pp->port_gid;	/* owner group id */
325 	vap->va_fsid = portdev;		/* file system id  */
326 	vap->va_nodeid = (ino64_t)0;	/* node id */
327 	vap->va_nlink = vp->v_count;	/* number of references to file */
328 	vap->va_size = (u_offset_t)pp->port_queue.portq_nent; /* file size */
329 	vap->va_atime = pp->port_ctime;	/* time of last access */
330 	vap->va_mtime = pp->port_ctime;	/* time of last modification */
331 	vap->va_ctime = pp->port_ctime;	/* time file ``created'' */
332 	vap->va_rdev = portdev;		/* device the file represents */
333 	vap->va_blksize = 0;		/* fundamental block size */
334 	vap->va_nblocks = (fsblkcnt64_t)0;	/* # of blocks allocated */
335 	vap->va_seq = 0;		/* sequence number */
336 
337 	return (0);
338 }
339 
340 /*
341  * Destroy the port.
342  */
343 /* ARGSUSED */
344 static void
345 port_inactive(struct vnode *vp, cred_t *cr, caller_context_t *ct)
346 {
347 	port_t 	*pp = VTOEP(vp);
348 	extern 	port_kstat_t port_kstat;
349 
350 	mutex_enter(&port_control.pc_mutex);
351 	port_control.pc_nents--;
352 	curproc->p_portcnt--;
353 	port_kstat.pks_ports.value.ui32--;
354 	mutex_exit(&port_control.pc_mutex);
355 	vn_free(vp);
356 	mutex_destroy(&pp->port_mutex);
357 	mutex_destroy(&pp->port_queue.portq_mutex);
358 	mutex_destroy(&pp->port_queue.portq_source_mutex);
359 	kmem_free(pp, sizeof (port_t));
360 }
361 
362 /* ARGSUSED */
363 static int
364 port_access(struct vnode *vp, int mode, int flags, cred_t *cr,
365     caller_context_t *ct)
366 {
367 	return (0);
368 }
369 
370 /* ARGSUSED */
371 static int
372 port_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
373 {
374 	*vpp = vp;
375 	return (0);
376 }
377