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-rw-r--r--drivers/md/dm-table.c14
-rw-r--r--include/linux/device-mapper.h11
2 files changed, 25 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 985c20a4f30e..7e2ec3c05550 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -71,6 +71,8 @@ struct dm_table {
void *event_context;
struct dm_md_mempools *mempools;
+
+ struct list_head target_callbacks;
};
/*
@@ -204,6 +206,7 @@ int dm_table_create(struct dm_table **result, fmode_t mode,
return -ENOMEM;
INIT_LIST_HEAD(&t->devices);
+ INIT_LIST_HEAD(&t->target_callbacks);
atomic_set(&t->holders, 0);
t->discards_supported = 1;
@@ -1225,10 +1228,17 @@ int dm_table_resume_targets(struct dm_table *t)
return 0;
}
+void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
+{
+ list_add(&cb->list, &t->target_callbacks);
+}
+EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
+
int dm_table_any_congested(struct dm_table *t, int bdi_bits)
{
struct dm_dev_internal *dd;
struct list_head *devices = dm_table_get_devices(t);
+ struct dm_target_callbacks *cb;
int r = 0;
list_for_each_entry(dd, devices, list) {
@@ -1243,6 +1253,10 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits)
bdevname(dd->dm_dev.bdev, b));
}
+ list_for_each_entry(cb, &t->target_callbacks, list)
+ if (cb->congested_fn)
+ r |= cb->congested_fn(cb, bdi_bits);
+
return r;
}
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 2970022faa63..4b1c63d478ab 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -193,6 +193,12 @@ struct dm_target {
char *error;
};
+/* Each target can link one of these into the table */
+struct dm_target_callbacks {
+ struct list_head list;
+ int (*congested_fn) (struct dm_target_callbacks *, int);
+};
+
int dm_register_target(struct target_type *t);
void dm_unregister_target(struct target_type *t);
@@ -269,6 +275,11 @@ int dm_table_add_target(struct dm_table *t, const char *type,
sector_t start, sector_t len, char *params);
/*
+ * Target_ctr should call this if it needs to add any callbacks.
+ */
+void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb);
+
+/*
* Finally call this to make the table ready for use.
*/
int dm_table_complete(struct dm_table *t);