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.
If there are no kcopyd jobs running, memory is released immediately.
Otherwise it gets freed later in the workqueue.
Signed-off-by: Milan Broz <mbroz@redhat.com>
---
[Still problems with this]
drivers/md/dm-snap.c | 28 +++++++++++++++++++++++-----
1 files changed, 23 insertions(+), 5 deletions(-)
Index: linux-2.6.19/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.19.orig/drivers/md/dm-snap.c 2006-12-06 20:49:41.000000000 +0000
+++ linux-2.6.19/drivers/md/dm-snap.c 2006-12-06 20:49:41.000000000 +0000
@@ -564,9 +564,17 @@ static int snapshot_ctr(struct dm_target
return r;
}
-static void __free_exceptions(struct dm_snapshot *s)
+/*
+ * If async is set, return immediately.
+ */
+static void __free_exceptions(struct dm_snapshot *s, unsigned async)
{
- kcopyd_client_destroy(s->kcopyd_client, 0);
+ async = kcopyd_client_destroy(s->kcopyd_client, async);
+ if (async) {
+ queue_work(ksnapd, &s->queued_bios_work);
+ return;
+ }
+
s->kcopyd_client = NULL;
exit_exception_table(&s->pending, pending_cache);
@@ -585,7 +593,8 @@ static void snapshot_dtr(struct dm_targe
/* After this returns there can be no new kcopyd jobs. */
unregister_snapshot(s);
- __free_exceptions(s);
+ if (s->valid)
+ __free_exceptions(s, 1);
dm_put_device(ti, s->origin);
dm_put_device(ti, s->cow);
@@ -611,14 +620,20 @@ static void flush_bios(struct bio *bio)
static void flush_queued_bios(void *data)
{
struct dm_snapshot *s = (struct dm_snapshot *) data;
- struct bio *queued_bios;
- unsigned long flags;
+// struct bio *queued_bios;
+// unsigned long flags;
+ if (!s->valid && s->kcopyd_client) {
+ __free_exceptions(s, 0);
+ return;
+ }
+/*
spin_lock_irqsave(&s->pe_lock, flags);
queued_bios = bio_list_get(&s->queued_bios);
spin_unlock_irqrestore(&s->pe_lock, flags);
flush_bios(queued_bios);
+*/
}
/*
@@ -651,6 +666,9 @@ static void __invalidate_snapshot(struct
s->valid = 0;
+ /* schedule release memory */
+ __free_exceptions(s, 1);
+
dm_table_event(s->table);
}