xref: /freebsd/sys/geom/vinum/geom_vinum_volume.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2007 Lukas Ertl
5  * All rights reserved.
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  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/bio.h>
32 #include <sys/lock.h>
33 #include <sys/malloc.h>
34 #include <sys/systm.h>
35 
36 #include <geom/geom.h>
37 #include <geom/vinum/geom_vinum_var.h>
38 #include <geom/vinum/geom_vinum.h>
39 
40 void
41 gv_volume_flush(struct gv_volume *v)
42 {
43 	struct gv_softc *sc;
44 	struct bio *bp;
45 
46 	KASSERT(v != NULL, ("NULL v"));
47 	sc = v->vinumconf;
48 	KASSERT(sc != NULL, ("NULL sc"));
49 
50 	bp = bioq_takefirst(v->wqueue);
51 	while (bp != NULL) {
52 		gv_volume_start(sc, bp);
53 		bp = bioq_takefirst(v->wqueue);
54 	}
55 }
56 
57 void
58 gv_volume_start(struct gv_softc *sc, struct bio *bp)
59 {
60 	struct gv_volume *v;
61 	struct gv_plex *p, *lp;
62 	int numwrites;
63 
64 	v = bp->bio_to->private;
65 	if (v == NULL || v->state != GV_VOL_UP) {
66 		g_io_deliver(bp, ENXIO);
67 		return;
68 	}
69 
70 	switch (bp->bio_cmd) {
71 	case BIO_READ:
72 		/*
73 		 * Try to find a good plex where we can send the request to,
74 		 * round-robin-style.  The plex either has to be up, or it's a
75 		 * degraded RAID5 plex. Check if we have delayed requests. Put
76 		 * this request on the delayed queue if so. This makes sure that
77 		 * we don't read old values.
78 		 */
79 		if (bioq_first(v->wqueue) != NULL) {
80 			bioq_insert_tail(v->wqueue, bp);
81 			break;
82 		}
83 		lp = v->last_read_plex;
84 		if (lp == NULL)
85 			lp = LIST_FIRST(&v->plexes);
86 		p = LIST_NEXT(lp, in_volume);
87 		if (p == NULL)
88 			p = LIST_FIRST(&v->plexes);
89 		do {
90 			if (p == NULL) {
91 				p = lp;
92 				break;
93 			}
94 			if ((p->state > GV_PLEX_DEGRADED) ||
95 			    (p->state >= GV_PLEX_DEGRADED &&
96 			    p->org == GV_PLEX_RAID5))
97 				break;
98 			p = LIST_NEXT(p, in_volume);
99 			if (p == NULL)
100 				p = LIST_FIRST(&v->plexes);
101 		} while (p != lp);
102 
103 		if ((p == NULL) ||
104 		    (p->org == GV_PLEX_RAID5 && p->state < GV_PLEX_DEGRADED) ||
105 		    (p->org != GV_PLEX_RAID5 && p->state <= GV_PLEX_DEGRADED)) {
106 			g_io_deliver(bp, ENXIO);
107 			return;
108 		}
109 		v->last_read_plex = p;
110 
111 		/* Hand it down to the plex logic. */
112 		gv_plex_start(p, bp);
113 		break;
114 
115 	case BIO_WRITE:
116 	case BIO_DELETE:
117 		/* Delay write-requests if any plex is synchronizing. */
118 		LIST_FOREACH(p, &v->plexes, in_volume) {
119 			if (p->flags & GV_PLEX_SYNCING) {
120 				bioq_insert_tail(v->wqueue, bp);
121 				return;
122 			}
123 		}
124 
125 		numwrites = 0;
126 		/* Give the BIO to each plex of this volume. */
127 		LIST_FOREACH(p, &v->plexes, in_volume) {
128 			if (p->state < GV_PLEX_DEGRADED)
129 				continue;
130 			gv_plex_start(p, bp);
131 			numwrites++;
132 		}
133 		if (numwrites == 0)
134 			g_io_deliver(bp, ENXIO);
135 		break;
136 	}
137 }
138 
139 void
140 gv_bio_done(struct gv_softc *sc, struct bio *bp)
141 {
142 	struct gv_volume *v __diagused;
143 	struct gv_plex *p;
144 	struct gv_sd *s;
145 
146 	s = bp->bio_caller1;
147 	KASSERT(s != NULL, ("gv_bio_done: NULL s"));
148 	p = s->plex_sc;
149 	KASSERT(p != NULL, ("gv_bio_done: NULL p"));
150 	v = p->vol_sc;
151 	KASSERT(v != NULL, ("gv_bio_done: NULL v"));
152 
153 	switch (p->org) {
154 	case GV_PLEX_CONCAT:
155 	case GV_PLEX_STRIPED:
156 		gv_plex_normal_done(p, bp);
157 		break;
158 	case GV_PLEX_RAID5:
159 		gv_plex_raid5_done(p, bp);
160 		break;
161 	}
162 
163 	gv_drive_done(s->drive_sc);
164 }
165