xref: /dragonfly/sys/vfs/nfs/nfs_iod.c (revision 0db87cb7)
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 
57 #include <sys/signal2.h>
58 #include <sys/thread2.h>
59 #include <sys/mutex2.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/tcp.h>
63 
64 #include "rpcv2.h"
65 #include "nfsproto.h"
66 #include "nfs.h"
67 #include "xdr_subs.h"
68 #include "nfsm_subs.h"
69 #include "nfsmount.h"
70 #include "nfsnode.h"
71 #include "nfsrtt.h"
72 
73 /*
74  * nfs service connection reader thread
75  */
76 void
77 nfssvc_iod_reader(void *arg)
78 {
79 	struct nfsmount *nmp = arg;
80 	struct nfsm_info *info;
81 	struct nfsreq *req;
82 	int error;
83 
84 	lwkt_gettoken(&nmp->nm_token);
85 
86 	if (nmp->nm_rxstate == NFSSVC_INIT)
87 		nmp->nm_rxstate = NFSSVC_PENDING;
88 	for (;;) {
89 		if (nmp->nm_rxstate == NFSSVC_WAITING) {
90 			if (TAILQ_FIRST(&nmp->nm_reqq) == NULL &&
91 			    TAILQ_FIRST(&nmp->nm_reqrxq) == NULL) {
92 				tsleep(&nmp->nm_rxstate, 0, "nfsidl", 0);
93 			} else {
94 				/*
95 				 * This can happen during shutdown, we don't
96 				 * want to hardloop.
97 				 */
98 				error = nfs_reply(nmp, NULL);
99 				if (error && error != EWOULDBLOCK) {
100 					tsleep(&nmp->nm_rxstate, 0,
101 						"nfsxxx", hz / 10);
102 				}
103 			}
104 			continue;
105 		}
106 		if (nmp->nm_rxstate != NFSSVC_PENDING)
107 			break;
108 		nmp->nm_rxstate = NFSSVC_WAITING;
109 
110 		/*
111 		 * Process requests which have received replies.  Only
112 		 * process the post-reply states.  If we get EINPROGRESS
113 		 * it means the request went back to an auth or retransmit
114 		 * state and we let the iod_writer thread deal with it.
115 		 *
116 		 * Any lock on the request is strictly temporary due to
117 		 * MP races (XXX).
118 		 *
119 		 * If the request completes we run the info->done call
120 		 * to finish up the I/O.
121 		 */
122 		while ((req = TAILQ_FIRST(&nmp->nm_reqrxq)) != NULL) {
123 			if (req->r_flags & R_LOCKED) {
124 				while (req->r_flags & R_LOCKED) {
125 					req->r_flags |= R_WANTED;
126 					tsleep(req, 0, "nfstrac", 0);
127 				}
128 				continue;
129 			}
130 			TAILQ_REMOVE(&nmp->nm_reqrxq, req, r_chain);
131 			info = req->r_info;
132 			KKASSERT(info);
133 			info->error = nfs_request(info,
134 						  NFSM_STATE_PROCESSREPLY,
135 						  NFSM_STATE_DONE);
136 			if (info->error == EINPROGRESS) {
137 				kprintf("rxq: move info %p back to txq\n", info);
138 				TAILQ_INSERT_TAIL(&nmp->nm_reqtxq, req, r_chain);
139 				nfssvc_iod_writer_wakeup(nmp);
140 			} else {
141 				atomic_subtract_int(&nmp->nm_bioqlen, 1);
142 				info->done(info);
143 			}
144 		}
145 	}
146 	nmp->nm_rxthread = NULL;
147 	nmp->nm_rxstate = NFSSVC_DONE;
148 
149 	lwkt_reltoken(&nmp->nm_token);
150 	wakeup(&nmp->nm_rxthread);
151 }
152 
153 /*
154  * nfs service connection writer thread
155  *
156  * The writer sits on the send side of the client's socket and
157  * does both the initial processing of BIOs and also transmission
158  * and retransmission of nfsreq's.
159  *
160  * The writer processes both new BIOs from nm_bioq and retransmit
161  * or state machine jumpbacks from nm_reqtxq
162  */
163 void
164 nfssvc_iod_writer(void *arg)
165 {
166 	struct nfsmount *nmp = arg;
167 	struct bio *bio;
168 	struct nfsreq *req;
169 	struct vnode *vp;
170 	nfsm_info_t info;
171 
172 	lwkt_gettoken(&nmp->nm_token);
173 
174 	if (nmp->nm_txstate == NFSSVC_INIT)
175 		nmp->nm_txstate = NFSSVC_PENDING;
176 
177 	for (;;) {
178 		if (nmp->nm_txstate == NFSSVC_WAITING) {
179 			tsleep(&nmp->nm_txstate, 0, "nfsidl", 0);
180 			continue;
181 		}
182 		if (nmp->nm_txstate != NFSSVC_PENDING)
183 			break;
184 		nmp->nm_txstate = NFSSVC_WAITING;
185 
186 		/*
187 		 * Eep, we could blow out the mbuf allocator if we just
188 		 * did everything the kernel wanted us to do.
189 		 */
190 		while ((bio = TAILQ_FIRST(&nmp->nm_bioq)) != NULL) {
191 			if (nmp->nm_reqqlen > nfs_maxasyncbio)
192 				break;
193 			TAILQ_REMOVE(&nmp->nm_bioq, bio, bio_act);
194 			vp = bio->bio_driver_info;
195 			nfs_startio(vp, bio, NULL);
196 		}
197 
198 		/*
199 		 * Process reauths & retransmits.  If we get an EINPROGRESS
200 		 * it means the state transitioned to WAITREPLY or later.
201 		 * Otherwise the request completed (probably with an error
202 		 * since we didn't get to a replied state).
203 		 */
204 		while ((req = TAILQ_FIRST(&nmp->nm_reqtxq)) != NULL) {
205 			TAILQ_REMOVE(&nmp->nm_reqtxq, req, r_chain);
206 			info = req->r_info;
207 			KKASSERT(info);
208 			info->error = nfs_request(info,
209 						  NFSM_STATE_AUTH,
210 						  NFSM_STATE_WAITREPLY);
211 			if (info->error == EINPROGRESS) {
212 				;
213 			} else {
214 				atomic_subtract_int(&nmp->nm_bioqlen, 1);
215 				info->done(info);
216 			}
217 		}
218 	}
219 	nmp->nm_txthread = NULL;
220 	nmp->nm_txstate = NFSSVC_DONE;
221 	lwkt_reltoken(&nmp->nm_token);
222 	wakeup(&nmp->nm_txthread);
223 }
224 
225 void
226 nfssvc_iod_stop1(struct nfsmount *nmp)
227 {
228 	nmp->nm_txstate = NFSSVC_STOPPING;
229 	nmp->nm_rxstate = NFSSVC_STOPPING;
230 }
231 
232 void
233 nfssvc_iod_stop2(struct nfsmount *nmp)
234 {
235 	wakeup(&nmp->nm_txstate);
236 	while (nmp->nm_txthread)
237 		tsleep(&nmp->nm_txthread, 0, "nfssttx", hz*2);
238 	wakeup(&nmp->nm_rxstate);
239 	while (nmp->nm_rxthread)
240 		tsleep(&nmp->nm_rxthread, 0, "nfsstrx", hz*2);
241 }
242 
243 void
244 nfssvc_iod_writer_wakeup(struct nfsmount *nmp)
245 {
246 	if (nmp->nm_txstate == NFSSVC_WAITING) {
247 		nmp->nm_txstate = NFSSVC_PENDING;
248 		wakeup(&nmp->nm_txstate);
249 	}
250 }
251 
252 void
253 nfssvc_iod_reader_wakeup(struct nfsmount *nmp)
254 {
255 	if (nmp->nm_rxstate == NFSSVC_WAITING) {
256 		nmp->nm_rxstate = NFSSVC_PENDING;
257 		wakeup(&nmp->nm_rxstate);
258 	}
259 }
260