geom_kern.c revision 145250
1/*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: head/sys/geom/geom_kern.c 145250 2005-04-18 21:21:26Z phk $"); 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/kernel.h> 42#include <sys/eventhandler.h> 43#include <sys/malloc.h> 44#include <sys/bio.h> 45#include <sys/sysctl.h> 46#include <sys/proc.h> 47#include <sys/kthread.h> 48#include <sys/lock.h> 49#include <sys/mutex.h> 50#include <sys/sbuf.h> 51#include <sys/sched.h> 52#include <sys/sx.h> 53#include <geom/geom.h> 54#include <geom/geom_int.h> 55 56MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures"); 57 58struct sx topology_lock; 59 60static struct proc *g_up_proc; 61 62int g_debugflags; 63int g_collectstats = 1; 64int g_shutdown; 65 66/* 67 * G_UP and G_DOWN are the two threads which push I/O through the 68 * stack. 69 * 70 * Things are procesed in a FIFO order, but these threads could be 71 * part of I/O prioritization by deciding which bios/bioqs to service 72 * in what order. 73 * 74 * We have only one thread in each direction, it is belived that until 75 * a very non-trivial workload in the UP/DOWN path this will be enough, 76 * but more than one can actually be run without problems. 77 * 78 * Holding the "mymutex" is a debugging feature: It prevents people 79 * from sleeping in the UP/DOWN I/O path by mistake or design (doing 80 * so almost invariably result in deadlocks since it stalls all I/O 81 * processing in the given direction. 82 */ 83 84static void 85g_up_procbody(void) 86{ 87 struct proc *p = g_up_proc; 88 struct thread *tp = FIRST_THREAD_IN_PROC(p); 89 90 mtx_assert(&Giant, MA_NOTOWNED); 91 mtx_lock_spin(&sched_lock); 92 sched_prio(tp, PRIBIO); 93 mtx_unlock_spin(&sched_lock); 94 for(;;) { 95 g_io_schedule_up(tp); 96 } 97} 98 99static struct kproc_desc g_up_kp = { 100 "g_up", 101 g_up_procbody, 102 &g_up_proc, 103}; 104 105static struct proc *g_down_proc; 106 107static void 108g_down_procbody(void) 109{ 110 struct proc *p = g_down_proc; 111 struct thread *tp = FIRST_THREAD_IN_PROC(p); 112 113 mtx_assert(&Giant, MA_NOTOWNED); 114 mtx_lock_spin(&sched_lock); 115 sched_prio(tp, PRIBIO); 116 mtx_unlock_spin(&sched_lock); 117 for(;;) { 118 g_io_schedule_down(tp); 119 } 120} 121 122static struct kproc_desc g_down_kp = { 123 "g_down", 124 g_down_procbody, 125 &g_down_proc, 126}; 127 128static struct proc *g_event_proc; 129 130static void 131g_event_procbody(void) 132{ 133 struct proc *p = g_event_proc; 134 struct thread *tp = FIRST_THREAD_IN_PROC(p); 135 struct root_hold_token *t; 136 137 mtx_assert(&Giant, MA_NOTOWNED); 138 mtx_lock_spin(&sched_lock); 139 sched_prio(tp, PRIBIO); 140 mtx_unlock_spin(&sched_lock); 141 t = root_mount_hold("GEOM"); 142 for(;;) { 143 g_run_events(); 144 if (t != 0) { 145 root_mount_rel(t); 146 t = NULL; 147 } 148 tsleep(&g_wait_event, PRIBIO, "-", hz/10); 149 } 150} 151 152static struct kproc_desc g_event_kp = { 153 "g_event", 154 g_event_procbody, 155 &g_event_proc, 156}; 157 158static void 159geom_shutdown(void *foo __unused) 160{ 161 162 g_shutdown = 1; 163} 164 165void 166g_init(void) 167{ 168 169 g_trace(G_T_TOPOLOGY, "g_ignition"); 170 sx_init(&topology_lock, "GEOM topology"); 171 g_io_init(); 172 g_event_init(); 173 g_ctl_init(); 174 mtx_lock(&Giant); 175 kproc_start(&g_event_kp); 176 kproc_start(&g_up_kp); 177 kproc_start(&g_down_kp); 178 mtx_unlock(&Giant); 179 EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL, 180 SHUTDOWN_PRI_FIRST); 181} 182 183static int 184sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS) 185{ 186 int error; 187 struct sbuf *sb; 188 189 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 190 g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL); 191 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 192 sbuf_delete(sb); 193 return error; 194} 195 196static int 197sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS) 198{ 199 int error; 200 struct sbuf *sb; 201 202 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 203 g_waitfor_event(g_confdot, sb, M_WAITOK, NULL); 204 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 205 sbuf_delete(sb); 206 return error; 207} 208 209static int 210sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS) 211{ 212 int error; 213 struct sbuf *sb; 214 215 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 216 g_waitfor_event(g_confxml, sb, M_WAITOK, NULL); 217 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 218 sbuf_delete(sb); 219 return error; 220} 221 222SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management"); 223 224SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD, 225 0, 0, sysctl_kern_geom_confxml, "", 226 "Dump the GEOM config in XML"); 227 228SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD, 229 0, 0, sysctl_kern_geom_confdot, "", 230 "Dump the GEOM config in dot"); 231 232SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD, 233 0, 0, sysctl_kern_geom_conftxt, "", 234 "Dump the GEOM config in txt"); 235 236TUNABLE_INT("kern.geom.debugflags", &g_debugflags); 237SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW, 238 &g_debugflags, 0, ""); 239 240SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW, 241 &g_collectstats, 0, ""); 242 243SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD, 244 0, sizeof(struct g_class), ""); 245SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD, 246 0, sizeof(struct g_geom), ""); 247SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD, 248 0, sizeof(struct g_provider), ""); 249SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD, 250 0, sizeof(struct g_consumer), ""); 251SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD, 252 0, sizeof(struct g_bioq), ""); 253