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subr_iostat.c revision 1.9
      1 /*	$NetBSD: subr_iostat.c,v 1.9 2006/04/21 13:58:10 yamt Exp $	*/
      2 /*	NetBSD: subr_disk.c,v 1.69 2005/05/29 22:24:15 christos Exp	*/
      3 
      4 /*-
      5  * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to The NetBSD Foundation
      9  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
     10  * NASA Ames Research Center.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the NetBSD
     23  *	Foundation, Inc. and its contributors.
     24  * 4. Neither the name of The NetBSD Foundation nor the names of its
     25  *    contributors may be used to endorse or promote products derived
     26  *    from this software without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     38  * POSSIBILITY OF SUCH DAMAGE.
     39  */
     40 
     41 /*
     42  * Copyright (c) 1982, 1986, 1988, 1993
     43  *	The Regents of the University of California.  All rights reserved.
     44  * (c) UNIX System Laboratories, Inc.
     45  * All or some portions of this file are derived from material licensed
     46  * to the University of California by American Telephone and Telegraph
     47  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     48  * the permission of UNIX System Laboratories, Inc.
     49  *
     50  * Redistribution and use in source and binary forms, with or without
     51  * modification, are permitted provided that the following conditions
     52  * are met:
     53  * 1. Redistributions of source code must retain the above copyright
     54  *    notice, this list of conditions and the following disclaimer.
     55  * 2. Redistributions in binary form must reproduce the above copyright
     56  *    notice, this list of conditions and the following disclaimer in the
     57  *    documentation and/or other materials provided with the distribution.
     58  * 3. Neither the name of the University nor the names of its contributors
     59  *    may be used to endorse or promote products derived from this software
     60  *    without specific prior written permission.
     61  *
     62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     72  * SUCH DAMAGE.
     73  *
     74  *	@(#)ufs_disksubr.c	8.5 (Berkeley) 1/21/94
     75  */
     76 
     77 #include <sys/cdefs.h>
     78 __KERNEL_RCSID(0, "$NetBSD: subr_iostat.c,v 1.9 2006/04/21 13:58:10 yamt Exp $");
     79 
     80 #include "opt_compat_netbsd.h"
     81 
     82 #include <sys/param.h>
     83 #include <sys/kernel.h>
     84 #include <sys/malloc.h>
     85 #include <sys/iostat.h>
     86 #include <sys/sysctl.h>
     87 
     88 /*
     89  * Function prototypes for sysctl nodes
     90  */
     91 static int	sysctl_hw_disknames(SYSCTLFN_PROTO);
     92 static int	sysctl_hw_iostatnames(SYSCTLFN_PROTO);
     93 static int	sysctl_hw_iostats(SYSCTLFN_PROTO);
     94 
     95 static int
     96 iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
     97 		u_int namelen);
     98 
     99 /*
    100  * A global list of all drives attached to the system.  May grow or
    101  * shrink over time.
    102  */
    103 struct iostatlist_head iostatlist = TAILQ_HEAD_INITIALIZER(iostatlist);
    104 int iostat_count;		/* number of drives in global drivelist */
    105 struct simplelock iostatlist_slock = SIMPLELOCK_INITIALIZER;
    106 
    107 /*
    108  * Searches the iostatlist for the iostat corresponding to the
    109  * name provided.
    110  */
    111 struct io_stats *
    112 iostat_find(const char *name)
    113 {
    114 	struct io_stats *iostatp;
    115 
    116 	KASSERT(name != NULL);
    117 
    118 	simple_lock(&iostatlist_slock);
    119 	TAILQ_FOREACH(iostatp, &iostatlist, io_link) {
    120 		if (strcmp(iostatp->io_name, name) == 0) {
    121 			break;
    122 		}
    123 	}
    124 	simple_unlock(&iostatlist_slock);
    125 
    126 	return iostatp;
    127 }
    128 
    129 /*
    130  * Allocate and initialise memory for the i/o statistics.
    131  */
    132 struct io_stats *
    133 iostat_alloc(int32_t type)
    134 {
    135 	int s;
    136 	struct io_stats *stats;
    137 
    138 	stats = malloc(sizeof(struct io_stats), M_DEVBUF, M_WAITOK|M_ZERO);
    139 	if (stats == NULL)
    140 		panic("iostat_alloc: cannot allocate memory for stats buffer");
    141 
    142 	stats->io_type = type;
    143 
    144 	/*
    145 	 * Set the attached timestamp.
    146 	 */
    147 	s = splclock();
    148 	stats->io_attachtime = mono_time;
    149 	splx(s);
    150 
    151 	/*
    152 	 * Link into the drivelist.
    153 	 */
    154 	simple_lock(&iostatlist_slock);
    155 	TAILQ_INSERT_TAIL(&iostatlist, stats, io_link);
    156 	iostat_count++;
    157 	simple_unlock(&iostatlist_slock);
    158 
    159 	return stats;
    160 }
    161 
    162 /*
    163  * Remove i/o from stats collection.
    164  */
    165 void
    166 iostat_free(struct io_stats *stats)
    167 {
    168 
    169 	/*
    170 	 * Remove from the iostat list.
    171 	 */
    172 	if (iostat_count == 0)
    173 		panic("iostat_free: iostat_count == 0");
    174 	simple_lock(&iostatlist_slock);
    175 	TAILQ_REMOVE(&iostatlist, stats, io_link);
    176 	iostat_count--;
    177 	simple_unlock(&iostatlist_slock);
    178 	free(stats, M_DEVBUF);
    179 }
    180 
    181 /*
    182  * Increment a iostat busy counter.  If the counter is going from
    183  * 0 to 1, set the timestamp.
    184  */
    185 void
    186 iostat_busy(struct io_stats *stats)
    187 {
    188 	int s;
    189 
    190 	/*
    191 	 * XXX We'd like to use something as accurate as microtime(),
    192 	 * but that doesn't depend on the system TOD clock.
    193 	 */
    194 	if (stats->io_busy++ == 0) {
    195 		s = splclock();
    196 		stats->io_timestamp = mono_time;
    197 		splx(s);
    198 	}
    199 }
    200 
    201 /*
    202  * Decrement a iostat busy counter, increment the byte count, total busy
    203  * time, and reset the timestamp.
    204  */
    205 void
    206 iostat_unbusy(struct io_stats *stats, long bcount, int read)
    207 {
    208 	int s;
    209 	struct timeval dv_time, diff_time;
    210 
    211 	if (stats->io_busy-- == 0) {
    212 		printf("%s: busy < 0\n", stats->io_name);
    213 		panic("iostat_unbusy");
    214 	}
    215 
    216 	s = splclock();
    217 	dv_time = mono_time;
    218 	splx(s);
    219 
    220 	timersub(&dv_time, &stats->io_timestamp, &diff_time);
    221 	timeradd(&stats->io_time, &diff_time, &stats->io_time);
    222 
    223 	stats->io_timestamp = dv_time;
    224 	if (bcount > 0) {
    225 		if (read) {
    226 			stats->io_rbytes += bcount;
    227 			stats->io_rxfer++;
    228 		} else {
    229 			stats->io_wbytes += bcount;
    230 			stats->io_wxfer++;
    231 		}
    232 	}
    233 }
    234 
    235 /*
    236  * Increment the seek counter.  This does look almost redundant but it
    237  * abstracts the stats gathering.
    238  */
    239 void
    240 iostat_seek(struct io_stats *stats)
    241 {
    242 
    243 	stats->io_seek++;
    244 }
    245 
    246 static int
    247 sysctl_hw_disknames(SYSCTLFN_ARGS)
    248 {
    249 
    250 	return iostati_getnames(1, oldp, oldlenp, newp, namelen);
    251 }
    252 
    253 static int
    254 sysctl_hw_iostatnames(SYSCTLFN_ARGS)
    255 {
    256 
    257 	return iostati_getnames(0, oldp, oldlenp, newp, namelen);
    258 }
    259 
    260 static int
    261 iostati_getnames(int disk_only, char *oldp, size_t *oldlenp, const void *newp,
    262 		 u_int namelen)
    263 {
    264 	char bf[IOSTATNAMELEN + 1];
    265 	char *where = oldp;
    266 	struct io_stats *stats;
    267 	size_t needed, left, slen;
    268 	int error, first;
    269 
    270 	if (newp != NULL)
    271 		return (EPERM);
    272 	if (namelen != 0)
    273 		return (EINVAL);
    274 
    275 	first = 1;
    276 	error = 0;
    277 	needed = 0;
    278 	left = *oldlenp;
    279 
    280 	simple_lock(&iostatlist_slock);
    281 	for (stats = TAILQ_FIRST(&iostatlist); stats != NULL;
    282 	    stats = TAILQ_NEXT(stats, io_link)) {
    283 		if ((disk_only == 1) && (stats->io_type != IOSTAT_DISK))
    284 			continue;
    285 
    286 		if (where == NULL)
    287 			needed += strlen(stats->io_name) + 1;
    288 		else {
    289 			memset(bf, 0, sizeof(bf));
    290 			if (first) {
    291 				strncpy(bf, stats->io_name, sizeof(bf));
    292 				first = 0;
    293 			} else {
    294 				bf[0] = ' ';
    295 				strncpy(bf + 1, stats->io_name,
    296 				    sizeof(bf) - 1);
    297 			}
    298 			bf[IOSTATNAMELEN] = '\0';
    299 			slen = strlen(bf);
    300 			if (left < slen + 1)
    301 				break;
    302 			/* +1 to copy out the trailing NUL byte */
    303 			error = copyout(bf, where, slen + 1);
    304 			if (error)
    305 				break;
    306 			where += slen;
    307 			needed += slen;
    308 			left -= slen;
    309 		}
    310 	}
    311 	simple_unlock(&iostatlist_slock);
    312 	*oldlenp = needed;
    313 	return (error);
    314 }
    315 
    316 static int
    317 sysctl_hw_iostats(SYSCTLFN_ARGS)
    318 {
    319 	struct io_sysctl sdrive;
    320 	struct io_stats *stats;
    321 	char *where = oldp;
    322 	size_t tocopy, left;
    323 	int error;
    324 
    325 	if (newp != NULL)
    326 		return (EPERM);
    327 
    328 	/*
    329 	 * The original hw.diskstats call was broken and did not require
    330 	 * the userland to pass in it's size of struct disk_sysctl.  This
    331 	 * was fixed after NetBSD 1.6 was released, and any applications
    332 	 * that do not pass in the size are given an error only, unless
    333 	 * we care about 1.6 compatibility.
    334 	 */
    335 	if (namelen == 0)
    336 #ifdef COMPAT_16
    337 		tocopy = offsetof(struct io_sysctl, busy);
    338 #else
    339 		return (EINVAL);
    340 #endif
    341 	else
    342 		tocopy = name[0];
    343 
    344 	if (where == NULL) {
    345 		*oldlenp = iostat_count * tocopy;
    346 		return (0);
    347 	}
    348 
    349 	error = 0;
    350 	left = *oldlenp;
    351 	memset(&sdrive, 0, sizeof(sdrive));
    352 	*oldlenp = 0;
    353 
    354 	simple_lock(&iostatlist_slock);
    355 	TAILQ_FOREACH(stats, &iostatlist, io_link) {
    356 		if (left < tocopy)
    357 			break;
    358 		strncpy(sdrive.name, stats->io_name, sizeof(sdrive.name));
    359 		sdrive.xfer = stats->io_rxfer + stats->io_wxfer;
    360 		sdrive.rxfer = stats->io_rxfer;
    361 		sdrive.wxfer = stats->io_wxfer;
    362 		sdrive.seek = stats->io_seek;
    363 		sdrive.bytes = stats->io_rbytes + stats->io_wbytes;
    364 		sdrive.rbytes = stats->io_rbytes;
    365 		sdrive.wbytes = stats->io_wbytes;
    366 		sdrive.attachtime_sec = stats->io_attachtime.tv_sec;
    367 		sdrive.attachtime_usec = stats->io_attachtime.tv_usec;
    368 		sdrive.timestamp_sec = stats->io_timestamp.tv_sec;
    369 		sdrive.timestamp_usec = stats->io_timestamp.tv_usec;
    370 		sdrive.time_sec = stats->io_time.tv_sec;
    371 		sdrive.time_usec = stats->io_time.tv_usec;
    372 		sdrive.busy = stats->io_busy;
    373 
    374 		error = copyout(&sdrive, where, min(tocopy, sizeof(sdrive)));
    375 		if (error)
    376 			break;
    377 		where += tocopy;
    378 		*oldlenp += tocopy;
    379 		left -= tocopy;
    380 	}
    381 	simple_unlock(&iostatlist_slock);
    382 	return (error);
    383 }
    384 
    385 SYSCTL_SETUP(sysctl_io_stats_setup, "sysctl i/o stats setup")
    386 {
    387 
    388 	sysctl_createv(clog, 0, NULL, NULL,
    389 		       CTLFLAG_PERMANENT,
    390 		       CTLTYPE_STRING, "disknames",
    391 		       SYSCTL_DESCR("List of disk drives present"),
    392 		       sysctl_hw_disknames, 0, NULL, 0,
    393 		       CTL_HW, HW_DISKNAMES, CTL_EOL);
    394 	sysctl_createv(clog, 0, NULL, NULL,
    395 		       CTLFLAG_PERMANENT,
    396 		       CTLTYPE_STRING, "iostatnames",
    397 		       SYSCTL_DESCR("I/O stats are being collected for these"
    398 				    " devices"),
    399 		       sysctl_hw_iostatnames, 0, NULL, 0,
    400 		       CTL_HW, HW_IOSTATNAMES, CTL_EOL);
    401 	sysctl_createv(clog, 0, NULL, NULL,
    402 		       CTLFLAG_PERMANENT,
    403 		       CTLTYPE_STRUCT, "iostats",
    404 		       SYSCTL_DESCR("Statistics on device I/O operations"),
    405 		       sysctl_hw_iostats, 0, NULL, 0,
    406 		       CTL_HW, HW_IOSTATS, CTL_EOL);
    407 }
    408