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/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_geom.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/conf.h>
#include <sys/disk.h>
#include <geom/geom_disk.h>
/*-
* Disk error is the preface to plaintive error messages
* about failing disk transfers. It prints messages of the form
* "hp0g: BLABLABLA cmd=read fsbn 12345 of 12344-12347"
* blkdone should be -1 if the position of the error is unknown.
* The message is printed with printf.
*/
void
disk_err(struct bio *bp, const char *what, int blkdone, int nl)
{
daddr_t sn;
if (bp->bio_dev != NULL)
printf("%s: %s ", devtoname(bp->bio_dev), what);
else if (bp->bio_disk != NULL)
printf("%s%d: %s ",
bp->bio_disk->d_name, bp->bio_disk->d_unit, what);
else
printf("disk??: %s ", what);
switch(bp->bio_cmd) {
case BIO_READ: printf("cmd=read "); break;
case BIO_WRITE: printf("cmd=write "); break;
case BIO_DELETE: printf("cmd=delete "); break;
case BIO_GETATTR: printf("cmd=getattr "); break;
default: printf("cmd=%x ", bp->bio_cmd); break;
}
sn = bp->bio_pblkno;
if (bp->bio_bcount <= DEV_BSIZE) {
printf("fsbn %jd%s", (intmax_t)sn, nl ? "\n" : "");
return;
}
if (blkdone >= 0) {
sn += blkdone;
printf("fsbn %jd of ", (intmax_t)sn);
}
printf("%jd-%jd", (intmax_t)bp->bio_pblkno,
(intmax_t)(bp->bio_pblkno + (bp->bio_bcount - 1) / DEV_BSIZE));
if (nl)
printf("\n");
}
/*
* BIO queue implementation
*/
void
bioq_init(struct bio_queue_head *head)
{
TAILQ_INIT(&head->queue);
head->last_offset = 0;
head->insert_point = NULL;
head->switch_point = NULL;
}
void
bioq_remove(struct bio_queue_head *head, struct bio *bp)
{
if (bp == head->switch_point)
head->switch_point = TAILQ_NEXT(bp, bio_queue);
if (bp == head->insert_point) {
head->insert_point = TAILQ_PREV(bp, bio_queue, bio_queue);
if (head->insert_point == NULL)
head->last_offset = 0;
} else if (bp == TAILQ_FIRST(&head->queue))
head->last_offset = bp->bio_offset;
TAILQ_REMOVE(&head->queue, bp, bio_queue);
if (TAILQ_FIRST(&head->queue) == head->switch_point)
head->switch_point = NULL;
}
void
bioq_flush(struct bio_queue_head *head, struct devstat *stp, int error)
{
struct bio *bp;
while ((bp = bioq_takefirst(head)) != NULL)
biofinish(bp, stp, error);
}
void
bioq_insert_tail(struct bio_queue_head *head, struct bio *bp)
{
TAILQ_INSERT_TAIL(&head->queue, bp, bio_queue);
}
struct bio *
bioq_first(struct bio_queue_head *head)
{
return (TAILQ_FIRST(&head->queue));
}
struct bio *
bioq_takefirst(struct bio_queue_head *head)
{
struct bio *bp;
bp = TAILQ_FIRST(&head->queue);
if (bp != NULL)
bioq_remove(head, bp);
return (bp);
}
/*
* Seek sort for disks.
*
* The buf_queue keep two queues, sorted in ascending block order. The first
* queue holds those requests which are positioned after the current block
* (in the first request); the second, which starts at queue->switch_point,
* 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 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.
*/
void
bioq_disksort(bioq, bp)
struct bio_queue_head *bioq;
struct bio *bp;
{
struct bio *bq;
struct bio *bn;
struct bio *be;
be = TAILQ_LAST(&bioq->queue, bio_queue);
/*
* If the queue is empty or we are an
* ordered transaction, then it's easy.
*/
if ((bq = bioq_first(bioq)) == NULL) {
bioq_insert_tail(bioq, bp);
return;
} else if (bioq->insert_point != NULL) {
/*
* A certain portion of the list is
* "locked" to preserve ordering, so
* we can only insert after the insert
* point.
*/
bq = bioq->insert_point;
} else {
/*
* If we lie before the last removed (currently active)
* request, and are not inserting ourselves into the
* "locked" portion of the list, then we must add ourselves
* to the second request list.
*/
if (bp->bio_offset < bioq->last_offset) {
bq = bioq->switch_point;
/*
* If we are starting a new secondary list,
* then it's easy.
*/
if (bq == NULL) {
bioq->switch_point = bp;
bioq_insert_tail(bioq, bp);
return;
}
/*
* If we lie ahead of the current switch point,
* insert us before the switch point and move
* the switch point.
*/
if (bp->bio_offset < bq->bio_offset) {
bioq->switch_point = bp;
TAILQ_INSERT_BEFORE(bq, bp, bio_queue);
return;
}
} else {
if (bioq->switch_point != NULL)
be = TAILQ_PREV(bioq->switch_point,
bio_queue, bio_queue);
/*
* If we lie between last_offset and bq,
* insert before bq.
*/
if (bp->bio_offset < bq->bio_offset) {
TAILQ_INSERT_BEFORE(bq, bp, bio_queue);
return;
}
}
}
/*
* Request is at/after our current position in the list.
* Optimize for sequential I/O by seeing if we go at the tail.
*/
if (bp->bio_offset > be->bio_offset) {
TAILQ_INSERT_AFTER(&bioq->queue, be, bp, bio_queue);
return;
}
/* Otherwise, insertion sort */
while ((bn = TAILQ_NEXT(bq, bio_queue)) != NULL) {
/*
* We want to go after the current request if it is the end
* of the first request list, or if the next request is a
* larger cylinder than our request.
*/
if (bn == bioq->switch_point
|| bp->bio_offset < bn->bio_offset)
break;
bq = bn;
}
TAILQ_INSERT_AFTER(&bioq->queue, bq, bp, bio_queue);
}
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