From: Milan Broz <mbroz@redhat.com>
Release memory if snapshot is invalidated.
All I/O operations on the full (invalidated) snapshot will
cause -EIO so no memory is needed anymore.
Snapshot is marked invalid and in workqueue is scheduled its
deallocation.
Signed-off-by: Milan Broz <mbroz@redhat.com>
---
---
drivers/md/dm-snap.c | 46 ++++++++++++++++++++++++++++++++++++----------
1 file changed, 36 insertions(+), 10 deletions(-)
Index: linux-2.6.22/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.22.orig/drivers/md/dm-snap.c 2007-05-14 17:17:29.000000000 +0200
+++ linux-2.6.22/drivers/md/dm-snap.c 2007-05-14 18:51:47.000000000 +0200
@@ -563,7 +563,7 @@ static int snapshot_ctr(struct dm_target
bad1:
return r;
}
-
+/*
static void __free_exceptions(struct dm_snapshot *s)
{
kcopyd_client_destroy(s->kcopyd_client);
@@ -574,18 +574,31 @@ static void __free_exceptions(struct dm_
s->store.destroy(&s->store);
}
+*/
+static void __schedule_drop_snapshot(struct dm_snapshot *s)
+{
+ /* invalidated -> already scheduled */
+ if (!s->valid)
+ return;
+
+ s->valid = 0;
+
+ queue_work(ksnapd, &s->queued_bios_work);
+}
static void snapshot_dtr(struct dm_target *ti)
{
struct dm_snapshot *s = (struct dm_snapshot *) ti->private;
- flush_workqueue(ksnapd);
-
/* Prevent further origin writes from using this snapshot. */
/* After this returns there can be no new kcopyd jobs. */
unregister_snapshot(s);
- __free_exceptions(s);
+ down_write(&s->lock);
+ __schedule_drop_snapshot(s);
+ up_write(&s->lock);
+
+ flush_workqueue(ksnapd);
dm_put_device(ti, s->origin);
dm_put_device(ti, s->cow);
@@ -612,6 +625,7 @@ static void flush_queued_bios(struct wor
{
struct dm_snapshot *s =
container_of(work, struct dm_snapshot, queued_bios_work);
+/*
struct bio *queued_bios;
unsigned long flags;
@@ -620,6 +634,23 @@ static void flush_queued_bios(struct wor
spin_unlock_irqrestore(&s->pe_lock, flags);
flush_bios(queued_bios);
+*/
+ BUG_ON(!s->kcopyd_client);
+ BUG_ON(s->valid);
+
+ kcopyd_client_destroy(s->kcopyd_client);
+ s->kcopyd_client = NULL;
+
+// down_write(&s->lock);
+ if (s->store.drop_snapshot)
+ s->store.drop_snapshot(&s->store);
+
+ exit_exception_table(&s->pending, pending_cache);
+ exit_exception_table(&s->complete, exception_cache);
+
+ s->store.destroy(&s->store);
+ dm_table_event(s->table);
+// up_write(&s->lock);
}
/*
@@ -647,12 +678,7 @@ static void __invalidate_snapshot(struct
else if (err == -ENOMEM)
DMERR("Invalidating snapshot: Unable to allocate exception.");
- if (s->store.drop_snapshot)
- s->store.drop_snapshot(&s->store);
-
- s->valid = 0;
-
- dm_table_event(s->table);
+ __schedule_drop_snapshot(s);
}
static void get_pending_exception(struct pending_exception *pe)