idr: Add new function idr_is_empty()

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/idr.h b/include/linux/idr.h
index 871a213a8477..9c95d210458b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -85,6 +85,7 @@ void idr_remove(struct idr *idp, int id);
 void idr_free(struct idr *idp, int id);
 void idr_destroy(struct idr *idp);
 void idr_init(struct idr *idp);
+bool idr_is_empty(struct idr *idp);
 
 /**
  * idr_preload_end - end preload section started with idr_preload()
diff --git a/lib/idr.c b/lib/idr.c
index bfe4db4e165f..1ba4956bfbff 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -869,6 +869,16 @@ void idr_init(struct idr *idp)
 }
 EXPORT_SYMBOL(idr_init);
 
+static int idr_has_entry(int id, void *p, void *data)
+{
+        return 1;
+}
+
+bool idr_is_empty(struct idr *idp)
+{
+        return !idr_for_each(idp, idr_has_entry, NULL);
+}
+EXPORT_SYMBOL(idr_is_empty);
 
 /**
  * DOC: IDA description