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path: root/drivers/md/dm-snap.c
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Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index d92980177b5..1c6485404db 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -39,6 +39,9 @@
*/
#define SNAPSHOT_PAGES 256
+struct workqueue_struct *ksnapd;
+static void flush_queued_bios(void *data);
+
struct pending_exception {
struct exception e;
@@ -488,6 +491,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
s->active = 0;
s->last_percent = 0;
init_rwsem(&s->lock);
+ spin_lock_init(&s->pe_lock);
s->table = ti->table;
/* Allocate hash table for COW data */
@@ -523,6 +527,9 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad6;
}
+ bio_list_init(&s->queued_bios);
+ INIT_WORK(&s->queued_bios_work, flush_queued_bios, s);
+
/* Add snapshot to the list of snapshots for this origin */
/* Exceptions aren't triggered till snapshot_resume() is called */
if (register_snapshot(s)) {
@@ -561,6 +568,8 @@ 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);
@@ -594,6 +603,19 @@ 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;
+
+ 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);
+}
+
/*
* Error a list of buffers.
*/
@@ -1240,8 +1262,17 @@ static int __init dm_snapshot_init(void)
goto bad5;
}
+ ksnapd = create_singlethread_workqueue("ksnapd");
+ if (!ksnapd) {
+ DMERR("Failed to create ksnapd workqueue.");
+ r = -ENOMEM;
+ goto bad6;
+ }
+
return 0;
+ bad6:
+ mempool_destroy(pending_pool);
bad5:
kmem_cache_destroy(pending_cache);
bad4:
@@ -1259,6 +1290,8 @@ static void __exit dm_snapshot_exit(void)
{
int r;
+ destroy_workqueue(ksnapd);
+
r = dm_unregister_target(&snapshot_target);
if (r)
DMERR("snapshot unregister failed %d", r);