linux/drivers/block/aoe/aoedev.c
Ed L. Cashin 3ae1c24e39 [PATCH] aoe [2/8]: support dynamic resizing of AoE devices
Allow the driver to recognize AoE devices that have changed size.
Devices not in use are updated automatically, and devices that are in
use are updated at user request.

Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-23 22:01:55 -08:00

204 lines
3.6 KiB
C

/* Copyright (c) 2004 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoedev.c
* AoE device utility functions; maintains device list.
*/
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/netdevice.h>
#include "aoe.h"
static struct aoedev *devlist;
static spinlock_t devlist_lock;
int
aoedev_isbusy(struct aoedev *d)
{
struct frame *f, *e;
f = d->frames;
e = f + d->nframes;
do {
if (f->tag != FREETAG) {
printk(KERN_DEBUG "aoe: %ld.%ld isbusy\n",
d->aoemajor, d->aoeminor);
return 1;
}
} while (++f < e);
return 0;
}
struct aoedev *
aoedev_by_aoeaddr(int maj, int min)
{
struct aoedev *d;
ulong flags;
spin_lock_irqsave(&devlist_lock, flags);
for (d=devlist; d; d=d->next)
if (d->aoemajor == maj && d->aoeminor == min)
break;
spin_unlock_irqrestore(&devlist_lock, flags);
return d;
}
static void
dummy_timer(ulong vp)
{
struct aoedev *d;
d = (struct aoedev *)vp;
if (d->flags & DEVFL_TKILL)
return;
d->timer.expires = jiffies + HZ;
add_timer(&d->timer);
}
/* called with devlist lock held */
static struct aoedev *
aoedev_newdev(ulong nframes)
{
struct aoedev *d;
struct frame *f, *e;
d = kzalloc(sizeof *d, GFP_ATOMIC);
if (d == NULL)
return NULL;
f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
if (f == NULL) {
kfree(d);
return NULL;
}
INIT_WORK(&d->work, aoecmd_sleepwork, d);
d->nframes = nframes;
d->frames = f;
e = f + nframes;
for (; f<e; f++)
f->tag = FREETAG;
spin_lock_init(&d->lock);
init_timer(&d->timer);
d->timer.data = (ulong) d;
d->timer.function = dummy_timer;
d->timer.expires = jiffies + HZ;
add_timer(&d->timer);
d->bufpool = NULL; /* defer to aoeblk_gdalloc */
INIT_LIST_HEAD(&d->bufq);
d->next = devlist;
devlist = d;
return d;
}
void
aoedev_downdev(struct aoedev *d)
{
struct frame *f, *e;
struct buf *buf;
struct bio *bio;
f = d->frames;
e = f + d->nframes;
for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
if (f->tag == FREETAG || f->buf == NULL)
continue;
buf = f->buf;
bio = buf->bio;
if (--buf->nframesout == 0) {
mempool_free(buf, d->bufpool);
bio_endio(bio, bio->bi_size, -EIO);
}
}
d->inprocess = NULL;
while (!list_empty(&d->bufq)) {
buf = container_of(d->bufq.next, struct buf, bufs);
list_del(d->bufq.next);
bio = buf->bio;
mempool_free(buf, d->bufpool);
bio_endio(bio, bio->bi_size, -EIO);
}
if (d->gd)
d->gd->capacity = 0;
d->flags &= ~(DEVFL_UP | DEVFL_PAUSE);
}
/* find it or malloc it */
struct aoedev *
aoedev_by_sysminor_m(ulong sysminor, ulong bufcnt)
{
struct aoedev *d;
ulong flags;
spin_lock_irqsave(&devlist_lock, flags);
for (d=devlist; d; d=d->next)
if (d->sysminor == sysminor)
break;
if (d == NULL) {
d = aoedev_newdev(bufcnt);
if (d == NULL) {
spin_unlock_irqrestore(&devlist_lock, flags);
printk(KERN_INFO "aoe: aoedev_set: aoedev_newdev failure.\n");
return NULL;
}
d->sysminor = sysminor;
d->aoemajor = AOEMAJOR(sysminor);
d->aoeminor = AOEMINOR(sysminor);
}
spin_unlock_irqrestore(&devlist_lock, flags);
return d;
}
static void
aoedev_freedev(struct aoedev *d)
{
if (d->gd) {
aoedisk_rm_sysfs(d);
del_gendisk(d->gd);
put_disk(d->gd);
}
kfree(d->frames);
if (d->bufpool)
mempool_destroy(d->bufpool);
kfree(d);
}
void
aoedev_exit(void)
{
struct aoedev *d;
ulong flags;
flush_scheduled_work();
while ((d = devlist)) {
devlist = d->next;
spin_lock_irqsave(&d->lock, flags);
aoedev_downdev(d);
d->flags |= DEVFL_TKILL;
spin_unlock_irqrestore(&d->lock, flags);
del_timer_sync(&d->timer);
aoedev_freedev(d);
}
}
int __init
aoedev_init(void)
{
spin_lock_init(&devlist_lock);
return 0;
}