aoe: user can ask driver to forget previously detected devices

When an AoE device is detected, the kernel is informed, and a new block device
is created.  If the device is unused, the block device corresponding to remote
device that is no longer available may be removed from the system by telling
the aoe driver to "flush" its list of devices.

Without this patch, software like GPFS and LVM may attempt to read from AoE
devices that were discovered earlier but are no longer present, blocking until
the I/O attempt times out.

Signed-off-by: Ed L. Cashin <ecashin@coraid.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ed L. Cashin 2008-02-08 04:20:03 -08:00 committed by Linus Torvalds
parent cf446f0dba
commit 262bf54144
5 changed files with 77 additions and 19 deletions

View File

@ -29,6 +29,8 @@ rm -f $dir/interfaces
mknod -m 0200 $dir/interfaces c $MAJOR 4
rm -f $dir/revalidate
mknod -m 0200 $dir/revalidate c $MAJOR 5
rm -f $dir/flush
mknod -m 0200 $dir/flush c $MAJOR 6
export n_partitions
mkshelf=`echo $0 | sed 's!mkdevs!mkshelf!'`

View File

@ -20,6 +20,7 @@ SUBSYSTEM=="aoe", KERNEL=="discover", NAME="etherd/%k", GROUP="disk", MODE="0220
SUBSYSTEM=="aoe", KERNEL=="err", NAME="etherd/%k", GROUP="disk", MODE="0440"
SUBSYSTEM=="aoe", KERNEL=="interfaces", NAME="etherd/%k", GROUP="disk", MODE="0220"
SUBSYSTEM=="aoe", KERNEL=="revalidate", NAME="etherd/%k", GROUP="disk", MODE="0220"
SUBSYSTEM=="aoe", KERNEL=="flush", NAME="etherd/%k", GROUP="disk", MODE="0220"
# aoe block devices
KERNEL=="etherd*", NAME="%k", GROUP="disk"

View File

@ -191,6 +191,7 @@ struct aoedev *aoedev_by_aoeaddr(int maj, int min);
struct aoedev *aoedev_by_sysminor_m(ulong sysminor);
void aoedev_downdev(struct aoedev *d);
int aoedev_isbusy(struct aoedev *d);
int aoedev_flush(const char __user *str, size_t size);
int aoenet_init(void);
void aoenet_exit(void);

View File

@ -15,6 +15,7 @@ enum {
MINOR_DISCOVER,
MINOR_INTERFACES,
MINOR_REVALIDATE,
MINOR_FLUSH,
MSGSZ = 2048,
NMSG = 100, /* message backlog to retain */
};
@ -43,6 +44,7 @@ static struct aoe_chardev chardevs[] = {
{ MINOR_DISCOVER, "discover" },
{ MINOR_INTERFACES, "interfaces" },
{ MINOR_REVALIDATE, "revalidate" },
{ MINOR_FLUSH, "flush" },
};
static int
@ -158,6 +160,9 @@ aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp
break;
case MINOR_REVALIDATE:
ret = revalidate(buf, cnt);
break;
case MINOR_FLUSH:
ret = aoedev_flush(buf, cnt);
}
if (ret == 0)
ret = cnt;

View File

@ -9,6 +9,10 @@
#include <linux/netdevice.h>
#include "aoe.h"
static void dummy_timer(ulong);
static void aoedev_freedev(struct aoedev *);
static void freetgt(struct aoetgt *t);
static struct aoedev *devlist;
static spinlock_t devlist_lock;
@ -108,6 +112,70 @@ aoedev_downdev(struct aoedev *d)
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(*t);
if (d->bufpool)
mempool_destroy(d->bufpool);
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;
}
/* find it or malloc it */
struct aoedev *
aoedev_by_sysminor_m(ulong sysminor)
@ -161,25 +229,6 @@ freetgt(struct aoetgt *t)
kfree(t);
}
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(*t);
if (d->bufpool)
mempool_destroy(d->bufpool);
kfree(d);
}
void
aoedev_exit(void)
{