Commit 262bf541 authored by Ed L. Cashin's avatar Ed L. Cashin Committed by Linus Torvalds
Browse files

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: default avatarEd L. Cashin <ecashin@coraid.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cf446f0d

Documentation/aoe/mkdevs.sh

+2 −0
Original line number Diff line number Diff line
@@ -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!'`

Documentation/aoe/udev.txt

+1 −0
Original line number Diff line number Diff line
@@ -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"

drivers/block/aoe/aoe.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/block/aoe/aoechr.c

+5 −0
Original line number Diff line number Diff line
@@ -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;

drivers/block/aoe/aoedev.c

+68 −19
Original line number Diff line number Diff line
@@ -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)

{

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