![Ed Cashin](/assets/img/avatar_default.png)
Andy Whitcroft reported an oops in aoe triggered by use of an
incorrectly initialised request_queue object:
[ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add
an uninitialized object, something is seriously wrong.
[ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu
[ 2645.959107] Call Trace:
[ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70
[ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0
[ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160
[ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe]
The request queue of an aoe device is not used but can be allocated in
code that does not sleep.
Bruno bisected this regression down to
cd43e26f07
block: Expose stacked device queues in sysfs
"This seems to generate /sys/block/$device/queue and its contents for
everyone who is using queues, not just for those queues that have a
non-NULL queue->request_fn."
Addresses http://bugs.launchpad.net/bugs/410198
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942
Note that embedding a queue inside another object has always been
an illegal construct, since the queues are reference counted and
must persist until the last reference is dropped. So aoe was
always buggy in this respect (Jens).
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Bruno Premont <bonbons@linux-vserver.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
279 lines
5.3 KiB
C
279 lines
5.3 KiB
C
/* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
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/*
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* aoedev.c
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* AoE device utility functions; maintains device list.
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*/
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#include <linux/hdreg.h>
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#include <linux/blkdev.h>
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#include <linux/netdevice.h>
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#include <linux/delay.h>
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#include "aoe.h"
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static void dummy_timer(ulong);
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static void aoedev_freedev(struct aoedev *);
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static void freetgt(struct aoedev *d, struct aoetgt *t);
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static void skbpoolfree(struct aoedev *d);
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static struct aoedev *devlist;
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static DEFINE_SPINLOCK(devlist_lock);
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struct aoedev *
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aoedev_by_aoeaddr(int maj, int min)
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{
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struct aoedev *d;
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ulong flags;
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spin_lock_irqsave(&devlist_lock, flags);
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for (d=devlist; d; d=d->next)
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if (d->aoemajor == maj && d->aoeminor == min)
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break;
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spin_unlock_irqrestore(&devlist_lock, flags);
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return d;
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}
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static void
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dummy_timer(ulong vp)
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{
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struct aoedev *d;
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d = (struct aoedev *)vp;
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if (d->flags & DEVFL_TKILL)
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return;
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d->timer.expires = jiffies + HZ;
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add_timer(&d->timer);
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}
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void
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aoedev_downdev(struct aoedev *d)
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{
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struct aoetgt **t, **te;
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struct frame *f, *e;
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struct buf *buf;
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struct bio *bio;
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t = d->targets;
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te = t + NTARGETS;
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for (; t < te && *t; t++) {
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f = (*t)->frames;
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e = f + (*t)->nframes;
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for (; f < e; f->tag = FREETAG, f->buf = NULL, f++) {
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if (f->tag == FREETAG || f->buf == NULL)
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continue;
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buf = f->buf;
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bio = buf->bio;
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if (--buf->nframesout == 0
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&& buf != d->inprocess) {
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mempool_free(buf, d->bufpool);
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bio_endio(bio, -EIO);
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}
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}
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(*t)->maxout = (*t)->nframes;
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(*t)->nout = 0;
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}
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buf = d->inprocess;
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if (buf) {
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bio = buf->bio;
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mempool_free(buf, d->bufpool);
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bio_endio(bio, -EIO);
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}
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d->inprocess = NULL;
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d->htgt = NULL;
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while (!list_empty(&d->bufq)) {
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buf = container_of(d->bufq.next, struct buf, bufs);
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list_del(d->bufq.next);
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bio = buf->bio;
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mempool_free(buf, d->bufpool);
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bio_endio(bio, -EIO);
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}
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if (d->gd)
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set_capacity(d->gd, 0);
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d->flags &= ~DEVFL_UP;
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}
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static void
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aoedev_freedev(struct aoedev *d)
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{
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struct aoetgt **t, **e;
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if (d->gd) {
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aoedisk_rm_sysfs(d);
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del_gendisk(d->gd);
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put_disk(d->gd);
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}
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t = d->targets;
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e = t + NTARGETS;
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for (; t < e && *t; t++)
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freetgt(d, *t);
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if (d->bufpool)
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mempool_destroy(d->bufpool);
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skbpoolfree(d);
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blk_cleanup_queue(d->blkq);
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kfree(d);
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}
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int
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aoedev_flush(const char __user *str, size_t cnt)
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{
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ulong flags;
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struct aoedev *d, **dd;
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struct aoedev *rmd = NULL;
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char buf[16];
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int all = 0;
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if (cnt >= 3) {
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if (cnt > sizeof buf)
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cnt = sizeof buf;
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if (copy_from_user(buf, str, cnt))
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return -EFAULT;
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all = !strncmp(buf, "all", 3);
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}
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flush_scheduled_work();
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spin_lock_irqsave(&devlist_lock, flags);
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dd = &devlist;
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while ((d = *dd)) {
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spin_lock(&d->lock);
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if ((!all && (d->flags & DEVFL_UP))
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|| (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
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|| d->nopen) {
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spin_unlock(&d->lock);
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dd = &d->next;
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continue;
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}
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*dd = d->next;
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aoedev_downdev(d);
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d->flags |= DEVFL_TKILL;
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spin_unlock(&d->lock);
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d->next = rmd;
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rmd = d;
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}
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spin_unlock_irqrestore(&devlist_lock, flags);
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while ((d = rmd)) {
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rmd = d->next;
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del_timer_sync(&d->timer);
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aoedev_freedev(d); /* must be able to sleep */
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}
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return 0;
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}
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/* I'm not really sure that this is a realistic problem, but if the
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network driver goes gonzo let's just leak memory after complaining. */
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static void
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skbfree(struct sk_buff *skb)
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{
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enum { Sms = 100, Tms = 3*1000};
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int i = Tms / Sms;
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if (skb == NULL)
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return;
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while (atomic_read(&skb_shinfo(skb)->dataref) != 1 && i-- > 0)
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msleep(Sms);
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if (i < 0) {
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printk(KERN_ERR
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"aoe: %s holds ref: %s\n",
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skb->dev ? skb->dev->name : "netif",
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"cannot free skb -- memory leaked.");
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return;
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}
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skb_shinfo(skb)->nr_frags = skb->data_len = 0;
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skb_trim(skb, 0);
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dev_kfree_skb(skb);
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}
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static void
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skbpoolfree(struct aoedev *d)
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{
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struct sk_buff *skb, *tmp;
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skb_queue_walk_safe(&d->skbpool, skb, tmp)
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skbfree(skb);
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__skb_queue_head_init(&d->skbpool);
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}
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/* find it or malloc it */
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struct aoedev *
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aoedev_by_sysminor_m(ulong sysminor)
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{
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struct aoedev *d;
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ulong flags;
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spin_lock_irqsave(&devlist_lock, flags);
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for (d=devlist; d; d=d->next)
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if (d->sysminor == sysminor)
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break;
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if (d)
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goto out;
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d = kcalloc(1, sizeof *d, GFP_ATOMIC);
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if (!d)
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goto out;
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INIT_WORK(&d->work, aoecmd_sleepwork);
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spin_lock_init(&d->lock);
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skb_queue_head_init(&d->sendq);
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skb_queue_head_init(&d->skbpool);
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init_timer(&d->timer);
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d->timer.data = (ulong) d;
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d->timer.function = dummy_timer;
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d->timer.expires = jiffies + HZ;
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add_timer(&d->timer);
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d->bufpool = NULL; /* defer to aoeblk_gdalloc */
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d->tgt = d->targets;
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INIT_LIST_HEAD(&d->bufq);
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d->sysminor = sysminor;
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d->aoemajor = AOEMAJOR(sysminor);
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d->aoeminor = AOEMINOR(sysminor);
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d->mintimer = MINTIMER;
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d->next = devlist;
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devlist = d;
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out:
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spin_unlock_irqrestore(&devlist_lock, flags);
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return d;
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}
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static void
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freetgt(struct aoedev *d, struct aoetgt *t)
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{
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struct frame *f, *e;
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f = t->frames;
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e = f + t->nframes;
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for (; f < e; f++)
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skbfree(f->skb);
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kfree(t->frames);
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kfree(t);
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}
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void
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aoedev_exit(void)
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{
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struct aoedev *d;
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ulong flags;
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flush_scheduled_work();
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while ((d = devlist)) {
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devlist = d->next;
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spin_lock_irqsave(&d->lock, flags);
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aoedev_downdev(d);
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d->flags |= DEVFL_TKILL;
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spin_unlock_irqrestore(&d->lock, flags);
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del_timer_sync(&d->timer);
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aoedev_freedev(d);
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}
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}
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int __init
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aoedev_init(void)
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{
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return 0;
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}
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