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