Fix ddtprune causing space leak

davidchenntnx · davidchenntnx · commit 3e71dd3f9d49 · 2025-11-27T00:33:03.000Z
In zio_ddt_free, if a pruned dde is still in ddt, it would do nothing and cause space leak. Signed-off-by: Chunwei Chen <david.chen@nutanix.com> Fixes #17982
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
@@ -4111,6 +4111,9 @@ zio_ddt_free(zio_t *zio)
 		ddt_phys_variant_t v = ddt_phys_select(ddt, dde, bp);
 		if (v != DDT_PHYS_NONE)
 			ddt_phys_decref(dde->dde_phys, v);
+		else
+			/* dde was pruned */
+			dde = NULL;
 	}
 	ddt_exit(ddt);
 

Original file line number	Diff line number	Diff line change
`@@ -4111,6 +4111,9 @@ zio_ddt_free(zio_t *zio)`
`4111`	`4111`	`ddt_phys_variant_t v = ddt_phys_select(ddt, dde, bp);`
`4112`	`4112`	`if (v != DDT_PHYS_NONE)`
`4113`	`4113`	`ddt_phys_decref(dde->dde_phys, v);`
	`4114`	`+ else`
	`4115`	`+ /* dde was pruned */`
	`4116`	`+ dde = NULL;`
`4114`	`4117`	`}`
`4115`	`4118`	`ddt_exit(ddt);`
`4116`	`4119`