linux/drivers/block/aoe/aoedev.c

278 lines
5.3 KiB
C

/* Copyright (c) 2007 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 <linux/delay.h>
#include "aoe.h"
static void dummy_timer(ulong);
static void aoedev_freedev(struct aoedev *);
static void freetgt(struct aoedev *d, struct aoetgt *t);
static void skbpoolfree(struct aoedev *d);
static struct aoedev *devlist;
static DEFINE_SPINLOCK(devlist_lock);
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);
}
void
aoedev_downdev(struct aoedev *d)
{
struct aoetgt **t, **te;
struct frame *f, *e;
struct buf *buf;
struct bio *bio;
t = d->targets;
te = t + NTARGETS;
for (; t < te && *t; t++) {
f = (*t)->frames;
e = f + (*t)->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
&& buf != d->inprocess) {
mempool_free(buf, d->bufpool);
bio_endio(bio, -EIO);
}
}
(*t)->maxout = (*t)->nframes;
(*t)->nout = 0;
}
buf = d->inprocess;
if (buf) {
bio = buf->bio;
mempool_free(buf, d->bufpool);
bio_endio(bio, -EIO);
}
d->inprocess = NULL;
d->htgt = 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, -EIO);
}
if (d->gd)
set_capacity(d->gd, 0);
d->flags &= ~DEVFL_UP;
}
static void
aoedev_freedev(struct aoedev *d)
{
struct aoetgt **t, **e;
if (d->gd) {
aoedisk_rm_sysfs(d);
del_gendisk(d->gd);
put_disk(d->gd);
}
t = d->targets;
e = t + NTARGETS;
for (; t < e && *t; t++)
freetgt(d, *t);
if (d->bufpool)
mempool_destroy(d->bufpool);
skbpoolfree(d);
kfree(d);
}
int
aoedev_flush(const char __user *str, size_t cnt)
{
ulong flags;
struct aoedev *d, **dd;
struct aoedev *rmd = NULL;
char buf[16];
int all = 0;
if (cnt >= 3) {
if (cnt > sizeof buf)
cnt = sizeof buf;
if (copy_from_user(buf, str, cnt))
return -EFAULT;
all = !strncmp(buf, "all", 3);
}
flush_scheduled_work();
spin_lock_irqsave(&devlist_lock, flags);
dd = &devlist;
while ((d = *dd)) {
spin_lock(&d->lock);
if ((!all && (d->flags & DEVFL_UP))
|| (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
|| d->nopen) {
spin_unlock(&d->lock);
dd = &d->next;
continue;
}
*dd = d->next;
aoedev_downdev(d);
d->flags |= DEVFL_TKILL;
spin_unlock(&d->lock);
d->next = rmd;
rmd = d;
}
spin_unlock_irqrestore(&devlist_lock, flags);
while ((d = rmd)) {
rmd = d->next;
del_timer_sync(&d->timer);
aoedev_freedev(d); /* must be able to sleep */
}
return 0;
}
/* I'm not really sure that this is a realistic problem, but if the
network driver goes gonzo let's just leak memory after complaining. */
static void
skbfree(struct sk_buff *skb)
{
enum { Sms = 100, Tms = 3*1000};
int i = Tms / Sms;
if (skb == NULL)
return;
while (atomic_read(&skb_shinfo(skb)->dataref) != 1 && i-- > 0)
msleep(Sms);
if (i < 0) {
printk(KERN_ERR
"aoe: %s holds ref: %s\n",
skb->dev ? skb->dev->name : "netif",
"cannot free skb -- memory leaked.");
return;
}
skb_shinfo(skb)->nr_frags = skb->data_len = 0;
skb_trim(skb, 0);
dev_kfree_skb(skb);
}
static void
skbpoolfree(struct aoedev *d)
{
struct sk_buff *skb, *tmp;
skb_queue_walk_safe(&d->skbpool, skb, tmp)
skbfree(skb);
__skb_queue_head_init(&d->skbpool);
}
/* find it or malloc it */
struct aoedev *
aoedev_by_sysminor_m(ulong sysminor)
{
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)
goto out;
d = kcalloc(1, sizeof *d, GFP_ATOMIC);
if (!d)
goto out;
INIT_WORK(&d->work, aoecmd_sleepwork);
spin_lock_init(&d->lock);
skb_queue_head_init(&d->sendq);
skb_queue_head_init(&d->skbpool);
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 */
d->tgt = d->targets;
INIT_LIST_HEAD(&d->bufq);
d->sysminor = sysminor;
d->aoemajor = AOEMAJOR(sysminor);
d->aoeminor = AOEMINOR(sysminor);
d->mintimer = MINTIMER;
d->next = devlist;
devlist = d;
out:
spin_unlock_irqrestore(&devlist_lock, flags);
return d;
}
static void
freetgt(struct aoedev *d, struct aoetgt *t)
{
struct frame *f, *e;
f = t->frames;
e = f + t->nframes;
for (; f < e; f++)
skbfree(f->skb);
kfree(t->frames);
kfree(t);
}
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)
{
return 0;
}