geom_kern.c revision 215687
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 215687 2010-11-22 16:47:53Z jh $"); 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 thread_lock(tp); 92 sched_prio(tp, PRIBIO); 93 thread_unlock(tp); 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 thread_lock(tp); 115 sched_prio(tp, PRIBIO); 116 thread_unlock(tp); 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); 135 136 mtx_assert(&Giant, MA_NOTOWNED); 137 thread_lock(tp); 138 sched_prio(tp, PRIBIO); 139 thread_unlock(tp); 140 g_run_events(); 141 /* NOTREACHED */ 142} 143 144static struct kproc_desc g_event_kp = { 145 "g_event", 146 g_event_procbody, 147 &g_event_proc, 148}; 149 150static void 151geom_shutdown(void *foo __unused) 152{ 153 154 g_shutdown = 1; 155} 156 157void 158g_init(void) 159{ 160 161 g_trace(G_T_TOPOLOGY, "g_ignition"); 162 sx_init(&topology_lock, "GEOM topology"); 163 g_io_init(); 164 g_event_init(); 165 g_ctl_init(); 166 mtx_lock(&Giant); 167 kproc_start(&g_event_kp); 168 kproc_start(&g_up_kp); 169 kproc_start(&g_down_kp); 170 mtx_unlock(&Giant); 171 EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL, 172 SHUTDOWN_PRI_FIRST); 173} 174 175static int 176sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS) 177{ 178 int error; 179 struct sbuf *sb; 180 181 sb = sbuf_new_auto(); 182 g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL); 183 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 184 sbuf_delete(sb); 185 return error; 186} 187 188static int 189sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS) 190{ 191 int error; 192 struct sbuf *sb; 193 194 sb = sbuf_new_auto(); 195 g_waitfor_event(g_confdot, sb, M_WAITOK, NULL); 196 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 197 sbuf_delete(sb); 198 return error; 199} 200 201static int 202sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS) 203{ 204 int error; 205 struct sbuf *sb; 206 207 sb = sbuf_new_auto(); 208 g_waitfor_event(g_confxml, sb, M_WAITOK, NULL); 209 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); 210 sbuf_delete(sb); 211 return error; 212} 213 214SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management"); 215 216SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD, 217 0, 0, sysctl_kern_geom_confxml, "", 218 "Dump the GEOM config in XML"); 219 220SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD, 221 0, 0, sysctl_kern_geom_confdot, "", 222 "Dump the GEOM config in dot"); 223 224SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD, 225 0, 0, sysctl_kern_geom_conftxt, "", 226 "Dump the GEOM config in txt"); 227 228TUNABLE_INT("kern.geom.debugflags", &g_debugflags); 229SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW, 230 &g_debugflags, 0, "Set various trace levels for GEOM debugging"); 231 232SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW, 233 &g_collectstats, 0, 234 "Control statistics collection on GEOM providers and consumers"); 235 236SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD, 237 0, sizeof(struct g_class), "sizeof(struct g_class)"); 238SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD, 239 0, sizeof(struct g_geom), "sizeof(struct g_geom)"); 240SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD, 241 0, sizeof(struct g_provider), "sizeof(struct g_provider)"); 242SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD, 243 0, sizeof(struct g_consumer), "sizeof(struct g_consumer)"); 244SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD, 245 0, sizeof(struct g_bioq), "sizeof(struct g_bioq)"); 246