1 files changed, 18 insertions, 4 deletions

diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c
index 9af760177445..486f50108bfa 100644
--- a/module/zfs/dsl_dir.c
+++ b/module/zfs/dsl_dir.c
@@ -54,6 +54,15 @@
 #include "zfs_prop.h"
 
 /*
+ * This controls if we verify the ZVOL quota or not.
+ * Currently, quotas are not implemented for ZVOLs.
+ * The quota size is the size of the ZVOL.
+ * The size of the volume already implies the ZVOL size quota.
+ * The quota mechanism can introduce a significant performance drop.
+ */
+static int zvol_enforce_quotas = B_TRUE;
+
+/*
  * Filesystem and Snapshot Limits
  * ------------------------------
  *
@@ -1311,7 +1320,9 @@ top_of_function:
 	 * If this transaction will result in a net free of space,
 	 * we want to let it through.
 	 */
-	if (ignorequota || netfree || dsl_dir_phys(dd)->dd_quota == 0)
+	if (ignorequota || netfree || dsl_dir_phys(dd)->dd_quota == 0 ||
+	    (dmu_objset_type(tx->tx_objset) == DMU_OST_ZVOL &&
+	    zvol_enforce_quotas == B_FALSE))
 		quota = UINT64_MAX;
 	else
 		quota = dsl_dir_phys(dd)->dd_quota;
@@ -1399,10 +1410,9 @@ top_of_function:
 		ignorequota = (dsl_dir_phys(dd)->dd_head_dataset_obj == 0);
 		first = B_FALSE;
 		goto top_of_function;
-
-	} else {
-		return (0);
 	}
+
+	return (0);
 }
 
 /*
@@ -2483,3 +2493,7 @@ dsl_dir_cancel_waiters(dsl_dir_t *dd)
 EXPORT_SYMBOL(dsl_dir_set_quota);
 EXPORT_SYMBOL(dsl_dir_set_reservation);
 #endif
+
+/* CSTYLED */
+ZFS_MODULE_PARAM(zfs, , zvol_enforce_quotas, INT, ZMOD_RW,
+	"Enable strict ZVOL quota enforcment");