xref: /freebsd/sys/geom/vinum/geom_vinum_volume.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 2007 Lukas Ertl
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
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 g_geom *gp;
61 	struct gv_volume *v;
62 	struct gv_plex *p, *lp;
63 	int numwrites;
64 
65 	gp = sc->geom;
66 	v = bp->bio_to->private;
67 	if (v == NULL || v->state != GV_VOL_UP) {
68 		g_io_deliver(bp, ENXIO);
69 		return;
70 	}
71 
72 	switch (bp->bio_cmd) {
73 	case BIO_READ:
74 		/*
75 		 * Try to find a good plex where we can send the request to,
76 		 * round-robin-style.  The plex either has to be up, or it's a
77 		 * degraded RAID5 plex. Check if we have delayed requests. Put
78 		 * this request on the delayed queue if so. This makes sure that
79 		 * we don't read old values.
80 		 */
81 		if (bioq_first(v->wqueue) != NULL) {
82 			bioq_insert_tail(v->wqueue, bp);
83 			break;
84 		}
85 		lp = v->last_read_plex;
86 		if (lp == NULL)
87 			lp = LIST_FIRST(&v->plexes);
88 		p = LIST_NEXT(lp, in_volume);
89 		if (p == NULL)
90 			p = LIST_FIRST(&v->plexes);
91 		do {
92 			if (p == NULL) {
93 				p = lp;
94 				break;
95 			}
96 			if ((p->state > GV_PLEX_DEGRADED) ||
97 			    (p->state >= GV_PLEX_DEGRADED &&
98 			    p->org == GV_PLEX_RAID5))
99 				break;
100 			p = LIST_NEXT(p, in_volume);
101 			if (p == NULL)
102 				p = LIST_FIRST(&v->plexes);
103 		} while (p != lp);
104 
105 		if ((p == NULL) ||
106 		    (p->org == GV_PLEX_RAID5 && p->state < GV_PLEX_DEGRADED) ||
107 		    (p->org != GV_PLEX_RAID5 && p->state <= GV_PLEX_DEGRADED)) {
108 			g_io_deliver(bp, ENXIO);
109 			return;
110 		}
111 		v->last_read_plex = p;
112 
113 		/* Hand it down to the plex logic. */
114 		gv_plex_start(p, bp);
115 		break;
116 
117 	case BIO_WRITE:
118 	case BIO_DELETE:
119 		/* Delay write-requests if any plex is synchronizing. */
120 		LIST_FOREACH(p, &v->plexes, in_volume) {
121 			if (p->flags & GV_PLEX_SYNCING) {
122 				bioq_insert_tail(v->wqueue, bp);
123 				return;
124 			}
125 		}
126 
127 		numwrites = 0;
128 		/* Give the BIO to each plex of this volume. */
129 		LIST_FOREACH(p, &v->plexes, in_volume) {
130 			if (p->state < GV_PLEX_DEGRADED)
131 				continue;
132 			gv_plex_start(p, bp);
133 			numwrites++;
134 		}
135 		if (numwrites == 0)
136 			g_io_deliver(bp, ENXIO);
137 		break;
138 	}
139 }
140 
141 void
142 gv_bio_done(struct gv_softc *sc, struct bio *bp)
143 {
144 	struct gv_volume *v;
145 	struct gv_plex *p;
146 	struct gv_sd *s;
147 
148 	s = bp->bio_caller1;
149 	KASSERT(s != NULL, ("gv_bio_done: NULL s"));
150 	p = s->plex_sc;
151 	KASSERT(p != NULL, ("gv_bio_done: NULL p"));
152 	v = p->vol_sc;
153 	KASSERT(v != NULL, ("gv_bio_done: NULL v"));
154 
155 	switch (p->org) {
156 	case GV_PLEX_CONCAT:
157 	case GV_PLEX_STRIPED:
158 		gv_plex_normal_done(p, bp);
159 		break;
160 	case GV_PLEX_RAID5:
161 		gv_plex_raid5_done(p, bp);
162 		break;
163 	}
164 }
165