projects/linux·commit 262bf541

aoe: user can ask driver to forget previously detected devices

262bf541 · Ed L. Cashin <[email protected]> · 2008-02-08 04:20:03 -08:00

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 <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
262bf54144ebcb78cd0d057d2705dc5fb7bba7ac
Parents
cf446f0d

Changes

5 files changed · +77 −19

FileStatusAddDelContent
Documentation/aoe/mkdevs.shmodified+2−0View file
Documentation/aoe/udev.txtmodified+1−0View file
drivers/block/aoe/aoe.hmodified+1−0View file
drivers/block/aoe/aoechr.cmodified+5−0View file
drivers/block/aoe/aoedev.cmodified+68−19View file

Documentation/aoe/mkdevs.sh

View file
diff --git a/Documentation/aoe/mkdevs.sh b/Documentation/aoe/mkdevs.sh
index 97374aa..44c0ab7 100644
--- a/Documentation/aoe/mkdevs.sh
+++ b/Documentation/aoe/mkdevs.sh
@@ -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

View file
diff --git a/Documentation/aoe/udev.txt b/Documentation/aoe/udev.txt
index 17e76c4..8686e78 100644
--- a/Documentation/aoe/udev.txt
+++ b/Documentation/aoe/udev.txt
@@ -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

View file
diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index aecaac3..2248ab2 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -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

View file
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index f112466..1bc85aa 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -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

View file
diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index a4d625a..e26f6f4 100644
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -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)
{