NetBSD/sys/kern/subr_disk.c

533 lines
16 KiB
C

/* $NetBSD: subr_disk.c,v 1.32 2001/11/30 01:31:30 enami Exp $ */
/*-
* Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.32 2001/11/30 01:31:30 enami Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/syslog.h>
#include <sys/time.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
/*
* A global list of all disks attached to the system. May grow or
* shrink over time.
*/
struct disklist_head disklist; /* TAILQ_HEAD */
int disk_count; /* number of drives in global disklist */
/*
* Seek sort for disks. We depend on the driver which calls us using b_resid
* as the current cylinder number.
*
* The argument bufq is an I/O queue for the device, on which there are
* actually two queues, sorted in ascending cylinder order. The first
* queue holds those requests which are positioned after the current
* cylinder (in the first request); the second holds requests which came
* in after their cylinder number was passed. Thus we implement a one-way
* scan, retracting after reaching the end of the drive to the first request
* on the second queue, at which time it becomes the first queue.
*
* A one-way scan is natural because of the way UNIX read-ahead blocks are
* allocated.
*
* This is further adjusted by any `barriers' which may exist in the queue.
* The bufq points to the last such ordered request.
*/
void
disksort_cylinder(struct buf_queue *bufq, struct buf *bp)
{
struct buf *bq, *nbq;
/*
* If there are ordered requests on the queue, we must start
* the elevator sort after the last of these.
*/
if ((bq = bufq->bq_barrier) == NULL)
bq = BUFQ_FIRST(bufq);
/*
* If the queue is empty, of if it's an ordered request,
* it's easy; we just go on the end.
*/
if (bq == NULL || (bp->b_flags & B_ORDERED) != 0) {
BUFQ_INSERT_TAIL(bufq, bp);
return;
}
/*
* If we lie after the first (currently active) request, then we
* must locate the second request list and add ourselves to it.
*/
if (bp->b_cylinder < bq->b_cylinder ||
(bp->b_cylinder == bq->b_cylinder &&
bp->b_rawblkno < bq->b_rawblkno)) {
while ((nbq = BUFQ_NEXT(bq)) != NULL) {
/*
* Check for an ``inversion'' in the normally ascending
* cylinder numbers, indicating the start of the second
* request list.
*/
if (nbq->b_cylinder < bq->b_cylinder) {
/*
* Search the second request list for the first
* request at a larger cylinder number. We go
* before that; if there is no such request, we
* go at end.
*/
do {
if (bp->b_cylinder < nbq->b_cylinder)
goto insert;
if (bp->b_cylinder == nbq->b_cylinder &&
bp->b_rawblkno < nbq->b_rawblkno)
goto insert;
bq = nbq;
} while ((nbq = BUFQ_NEXT(bq)) != NULL);
goto insert; /* after last */
}
bq = nbq;
}
/*
* No inversions... we will go after the last, and
* be the first request in the second request list.
*/
goto insert;
}
/*
* Request is at/after the current request...
* sort in the first request list.
*/
while ((nbq = BUFQ_NEXT(bq)) != NULL) {
/*
* We want to go after the current request if there is an
* inversion after it (i.e. it is the end of the first
* request list), or if the next request is a larger cylinder
* than our request.
*/
if (nbq->b_cylinder < bq->b_cylinder ||
bp->b_cylinder < nbq->b_cylinder ||
(bp->b_cylinder == nbq->b_cylinder &&
bp->b_rawblkno < nbq->b_rawblkno))
goto insert;
bq = nbq;
}
/*
* Neither a second list nor a larger request... we go at the end of
* the first list, which is the same as the end of the whole schebang.
*/
insert: BUFQ_INSERT_AFTER(bufq, bq, bp);
}
/*
* Seek sort for disks. This version sorts based on b_rawblkno, which
* indicates the block number.
*
* As before, there are actually two queues, sorted in ascendening block
* order. The first queue holds those requests which are positioned after
* the current block (in the first request); the second holds requests which
* came in after their block number was passed. Thus we implement a one-way
* scan, retracting after reaching the end of the driver to the first request
* on the second queue, at which time it becomes the first queue.
*
* A one-way scan is natural because of the way UNIX read-ahead blocks are
* allocated.
*
* This is further adjusted by any `barriers' which may exist in the queue.
* The bufq points to the last such ordered request.
*/
void
disksort_blkno(struct buf_queue *bufq, struct buf *bp)
{
struct buf *bq, *nbq;
/*
* If there are ordered requests on the queue, we must start
* the elevator sort after the last of these.
*/
if ((bq = bufq->bq_barrier) == NULL)
bq = BUFQ_FIRST(bufq);
/*
* If the queue is empty, or if it's an ordered request,
* it's easy; we just go on the end.
*/
if (bq == NULL || (bp->b_flags & B_ORDERED) != 0) {
BUFQ_INSERT_TAIL(bufq, bp);
return;
}
/*
* If we lie after the first (currently active) request, then we
* must locate the second request list and add ourselves to it.
*/
if (bp->b_rawblkno < bq->b_rawblkno) {
while ((nbq = BUFQ_NEXT(bq)) != NULL) {
/*
* Check for an ``inversion'' in the normally ascending
* block numbers, indicating the start of the second
* request list.
*/
if (nbq->b_rawblkno < bq->b_rawblkno) {
/*
* Search the second request list for the first
* request at a larger block number. We go
* after that; if there is no such request, we
* go at the end.
*/
do {
if (bp->b_rawblkno < nbq->b_rawblkno)
goto insert;
bq = nbq;
} while ((nbq = BUFQ_NEXT(bq)) != NULL);
goto insert; /* after last */
}
bq = nbq;
}
/*
* No inversions... we will go after the last, and
* be the first request in the second request list.
*/
goto insert;
}
/*
* Request is at/after the current request...
* sort in the first request list.
*/
while ((nbq = BUFQ_NEXT(bq)) != NULL) {
/*
* We want to go after the current request if there is an
* inversion after it (i.e. it is the end of the first
* request list), or if the next request is a larger cylinder
* than our request.
*/
if (nbq->b_rawblkno < bq->b_rawblkno ||
bp->b_rawblkno < nbq->b_rawblkno)
goto insert;
bq = nbq;
}
/*
* Neither a second list nor a larger request... we go at the end of
* the first list, which is the same as the end of the whole schebang.
*/
insert: BUFQ_INSERT_AFTER(bufq, bq, bp);
}
/*
* Seek non-sort for disks. This version simply inserts requests at
* the tail of the queue.
*/
void
disksort_tail(struct buf_queue *bufq, struct buf *bp)
{
BUFQ_INSERT_TAIL(bufq, bp);
}
/*
* Compute checksum for disk label.
*/
u_int
dkcksum(struct disklabel *lp)
{
u_short *start, *end;
u_short sum = 0;
start = (u_short *)lp;
end = (u_short *)&lp->d_partitions[lp->d_npartitions];
while (start < end)
sum ^= *start++;
return (sum);
}
/*
* Disk error is the preface to plaintive error messages
* about failing disk transfers. It prints messages of the form
hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
* if the offset of the error in the transfer and a disk label
* are both available. blkdone should be -1 if the position of the error
* is unknown; the disklabel pointer may be null from drivers that have not
* been converted to use them. The message is printed with printf
* if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
* The message should be completed (with at least a newline) with printf
* or addlog, respectively. There is no trailing space.
*/
void
diskerr(struct buf *bp, char *dname, char *what, int pri, int blkdone,
struct disklabel *lp)
{
int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev);
void (*pr)(const char *, ...);
char partname = 'a' + part;
int sn;
if (pri != LOG_PRINTF) {
static const char fmt[] = "";
log(pri, fmt);
pr = addlog;
} else
pr = printf;
(*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
bp->b_flags & B_READ ? "read" : "writ");
sn = bp->b_blkno;
if (bp->b_bcount <= DEV_BSIZE)
(*pr)("%d", sn);
else {
if (blkdone >= 0) {
sn += blkdone;
(*pr)("%d of ", sn);
}
(*pr)("%d-%d", bp->b_blkno,
bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
}
if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
sn += lp->d_partitions[part].p_offset;
(*pr)(" (%s%d bn %d; cn %d", dname, unit, sn,
sn / lp->d_secpercyl);
sn %= lp->d_secpercyl;
(*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
}
}
/*
* Initialize the disklist. Called by main() before autoconfiguration.
*/
void
disk_init(void)
{
TAILQ_INIT(&disklist);
disk_count = 0;
}
/*
* Searches the disklist for the disk corresponding to the
* name provided.
*/
struct disk *
disk_find(char *name)
{
struct disk *diskp;
if ((name == NULL) || (disk_count <= 0))
return (NULL);
for (diskp = disklist.tqh_first; diskp != NULL;
diskp = diskp->dk_link.tqe_next)
if (strcmp(diskp->dk_name, name) == 0)
return (diskp);
return (NULL);
}
/*
* Attach a disk.
*/
void
disk_attach(struct disk *diskp)
{
int s;
/*
* Allocate and initialize the disklabel structures. Note that
* it's not safe to sleep here, since we're probably going to be
* called during autoconfiguration.
*/
diskp->dk_label = malloc(sizeof(struct disklabel), M_DEVBUF, M_NOWAIT);
diskp->dk_cpulabel = malloc(sizeof(struct cpu_disklabel), M_DEVBUF,
M_NOWAIT);
if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL))
panic("disk_attach: can't allocate storage for disklabel");
memset(diskp->dk_label, 0, sizeof(struct disklabel));
memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel));
/*
* Set the attached timestamp.
*/
s = splclock();
diskp->dk_attachtime = mono_time;
splx(s);
/*
* Link into the disklist.
*/
TAILQ_INSERT_TAIL(&disklist, diskp, dk_link);
++disk_count;
}
/*
* Detach a disk.
*/
void
disk_detach(struct disk *diskp)
{
/*
* Remove from the disklist.
*/
if (--disk_count < 0)
panic("disk_detach: disk_count < 0");
TAILQ_REMOVE(&disklist, diskp, dk_link);
/*
* Free the space used by the disklabel structures.
*/
free(diskp->dk_label, M_DEVBUF);
free(diskp->dk_cpulabel, M_DEVBUF);
}
/*
* Increment a disk's busy counter. If the counter is going from
* 0 to 1, set the timestamp.
*/
void
disk_busy(struct disk *diskp)
{
int s;
/*
* XXX We'd like to use something as accurate as microtime(),
* but that doesn't depend on the system TOD clock.
*/
if (diskp->dk_busy++ == 0) {
s = splclock();
diskp->dk_timestamp = mono_time;
splx(s);
}
}
/*
* Decrement a disk's busy counter, increment the byte count, total busy
* time, and reset the timestamp.
*/
void
disk_unbusy(struct disk *diskp, long bcount)
{
int s;
struct timeval dv_time, diff_time;
if (diskp->dk_busy-- == 0) {
printf("%s: dk_busy < 0\n", diskp->dk_name);
panic("disk_unbusy");
}
s = splclock();
dv_time = mono_time;
splx(s);
timersub(&dv_time, &diskp->dk_timestamp, &diff_time);
timeradd(&diskp->dk_time, &diff_time, &diskp->dk_time);
diskp->dk_timestamp = dv_time;
if (bcount > 0) {
diskp->dk_bytes += bcount;
diskp->dk_xfer++;
}
}
/*
* Reset the metrics counters on the given disk. Note that we cannot
* reset the busy counter, as it may case a panic in disk_unbusy().
* We also must avoid playing with the timestamp information, as it
* may skew any pending transfer results.
*/
void
disk_resetstat(struct disk *diskp)
{
int s = splbio(), t;
diskp->dk_xfer = 0;
diskp->dk_bytes = 0;
t = splclock();
diskp->dk_attachtime = mono_time;
splx(t);
timerclear(&diskp->dk_time);
splx(s);
}