xref: /dflybsd-src/sys/vfs/nfs/nfs_iod.c (revision c9e9fb21c9ab82a8102647d67bcf956e0aba60af)
1 /*
2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 /*
35  * NFSIOD operations - now built into the kernel.
36  */
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/proc.h>
40 #include <sys/malloc.h>
41 #include <sys/mount.h>
42 #include <sys/kernel.h>
43 #include <sys/mbuf.h>
44 #include <sys/vnode.h>
45 #include <sys/fcntl.h>
46 #include <sys/protosw.h>
47 #include <sys/resourcevar.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/socketops.h>
51 #include <sys/syslog.h>
52 #include <sys/thread.h>
53 #include <sys/tprintf.h>
54 #include <sys/sysctl.h>
55 #include <sys/signalvar.h>
56 #include <sys/mutex.h>
57 
58 #include <sys/signal2.h>
59 #include <sys/thread2.h>
60 #include <sys/mutex2.h>
61 #include <sys/mplock2.h>
62 
63 #include <netinet/in.h>
64 #include <netinet/tcp.h>
65 
66 #include "rpcv2.h"
67 #include "nfsproto.h"
68 #include "nfs.h"
69 #include "xdr_subs.h"
70 #include "nfsm_subs.h"
71 #include "nfsmount.h"
72 #include "nfsnode.h"
73 #include "nfsrtt.h"
74 
75 /*
76  * nfs service connection reader thread
77  */
78 void
79 nfssvc_iod_reader(void *arg)
80 {
81 	struct nfsmount *nmp = arg;
82 	struct nfsm_info *info;
83 	struct nfsreq *req;
84 	int error;
85 
86 	get_mplock();
87 
88 	if (nmp->nm_rxstate == NFSSVC_INIT)
89 		nmp->nm_rxstate = NFSSVC_PENDING;
90 	crit_enter();
91 	for (;;) {
92 		if (nmp->nm_rxstate == NFSSVC_WAITING) {
93 			if (TAILQ_FIRST(&nmp->nm_reqq) == NULL &&
94 			    TAILQ_FIRST(&nmp->nm_reqrxq) == NULL) {
95 				tsleep(&nmp->nm_rxstate, 0, "nfsidl", 0);
96 			} else {
97 				/*
98 				 * This can happen during shutdown, we don't
99 				 * want to hardloop.
100 				 */
101 				error = nfs_reply(nmp, NULL);
102 				if (error && error != EWOULDBLOCK) {
103 					tsleep(&nmp->nm_rxstate, 0,
104 						"nfsxxx", hz / 10);
105 				}
106 			}
107 			continue;
108 		}
109 		if (nmp->nm_rxstate != NFSSVC_PENDING)
110 			break;
111 		nmp->nm_rxstate = NFSSVC_WAITING;
112 
113 		/*
114 		 * Process requests which have received replies.  Only
115 		 * process the post-reply states.  If we get EINPROGRESS
116 		 * it means the request went back to an auth or retransmit
117 		 * state and we let the iod_writer thread deal with it.
118 		 *
119 		 * Any lock on the request is strictly temporary due to
120 		 * MP races (XXX).
121 		 *
122 		 * If the request completes we run the info->done call
123 		 * to finish up the I/O.
124 		 */
125 		while ((req = TAILQ_FIRST(&nmp->nm_reqrxq)) != NULL) {
126 			if (req->r_flags & R_LOCKED) {
127 				while (req->r_flags & R_LOCKED) {
128 					req->r_flags |= R_WANTED;
129 					tsleep(req, 0, "nfstrac", 0);
130 				}
131 				continue;
132 			}
133 			TAILQ_REMOVE(&nmp->nm_reqrxq, req, r_chain);
134 			crit_exit();
135 			info = req->r_info;
136 			KKASSERT(info);
137 			info->error = nfs_request(info,
138 						  NFSM_STATE_PROCESSREPLY,
139 						  NFSM_STATE_DONE);
140 			if (info->error == EINPROGRESS) {
141 				kprintf("rxq: move info %p back to txq\n", info);
142 				TAILQ_INSERT_TAIL(&nmp->nm_reqtxq, req, r_chain);
143 				nfssvc_iod_writer_wakeup(nmp);
144 			} else {
145 				atomic_subtract_int(&nmp->nm_bioqlen, 1);
146 				info->done(info);
147 			}
148 			crit_enter();
149 		}
150 	}
151 	crit_exit();
152 	nmp->nm_rxthread = NULL;
153 	nmp->nm_rxstate = NFSSVC_DONE;
154 	wakeup(&nmp->nm_rxthread);
155 }
156 
157 /*
158  * nfs service connection writer thread
159  *
160  * The writer sits on the send side of the client's socket and
161  * does both the initial processing of BIOs and also transmission
162  * and retransmission of nfsreq's.
163  *
164  * The writer processes both new BIOs from nm_bioq and retransmit
165  * or state machine jumpbacks from nm_reqtxq
166  */
167 void
168 nfssvc_iod_writer(void *arg)
169 {
170 	struct nfsmount *nmp = arg;
171 	struct bio *bio;
172 	struct nfsreq *req;
173 	struct vnode *vp;
174 	nfsm_info_t info;
175 
176 	get_mplock();
177 
178 	if (nmp->nm_txstate == NFSSVC_INIT)
179 		nmp->nm_txstate = NFSSVC_PENDING;
180 
181 	crit_enter();
182 	for (;;) {
183 		if (nmp->nm_txstate == NFSSVC_WAITING) {
184 			tsleep(&nmp->nm_txstate, 0, "nfsidl", 0);
185 			continue;
186 		}
187 		if (nmp->nm_txstate != NFSSVC_PENDING)
188 			break;
189 		nmp->nm_txstate = NFSSVC_WAITING;
190 
191 		/*
192 		 * Eep, we could blow out the mbuf allocator if we just
193 		 * did everything the kernel wanted us to do.
194 		 */
195 		while ((bio = TAILQ_FIRST(&nmp->nm_bioq)) != NULL) {
196 			if (nmp->nm_reqqlen > nfs_maxasyncbio)
197 				break;
198 			TAILQ_REMOVE(&nmp->nm_bioq, bio, bio_act);
199 			vp = bio->bio_driver_info;
200 			crit_exit();
201 			nfs_startio(vp, bio, NULL);
202 			crit_enter();
203 		}
204 
205 		/*
206 		 * Process reauths & retransmits.  If we get an EINPROGRESS
207 		 * it means the state transitioned to WAITREPLY or later.
208 		 * Otherwise the request completed (probably with an error
209 		 * since we didn't get to a replied state).
210 		 */
211 		while ((req = TAILQ_FIRST(&nmp->nm_reqtxq)) != NULL) {
212 			TAILQ_REMOVE(&nmp->nm_reqtxq, req, r_chain);
213 			info = req->r_info;
214 			KKASSERT(info);
215 			crit_exit();
216 			info->error = nfs_request(info,
217 						  NFSM_STATE_AUTH,
218 						  NFSM_STATE_WAITREPLY);
219 			crit_enter();
220 			if (info->error == EINPROGRESS) {
221 				;
222 			} else {
223 				atomic_subtract_int(&nmp->nm_bioqlen, 1);
224 				info->done(info);
225 			}
226 		}
227 	}
228 	crit_exit();
229 	nmp->nm_txthread = NULL;
230 	nmp->nm_txstate = NFSSVC_DONE;
231 	wakeup(&nmp->nm_txthread);
232 }
233 
234 void
235 nfssvc_iod_stop1(struct nfsmount *nmp)
236 {
237 	crit_enter();
238 	nmp->nm_txstate = NFSSVC_STOPPING;
239 	nmp->nm_rxstate = NFSSVC_STOPPING;
240 	crit_exit();
241 }
242 
243 void
244 nfssvc_iod_stop2(struct nfsmount *nmp)
245 {
246 	wakeup(&nmp->nm_txstate);
247 	while (nmp->nm_txthread)
248 		tsleep(&nmp->nm_txthread, 0, "nfssttx", hz*2);
249 	wakeup(&nmp->nm_rxstate);
250 	while (nmp->nm_rxthread)
251 		tsleep(&nmp->nm_rxthread, 0, "nfsstrx", hz*2);
252 }
253 
254 void
255 nfssvc_iod_writer_wakeup(struct nfsmount *nmp)
256 {
257 	if (nmp->nm_txstate == NFSSVC_WAITING) {
258 		nmp->nm_txstate = NFSSVC_PENDING;
259 		wakeup(&nmp->nm_txstate);
260 	}
261 }
262 
263 void
264 nfssvc_iod_reader_wakeup(struct nfsmount *nmp)
265 {
266 	if (nmp->nm_rxstate == NFSSVC_WAITING) {
267 		nmp->nm_rxstate = NFSSVC_PENDING;
268 		wakeup(&nmp->nm_rxstate);
269 	}
270 }
271