kclient: do not recurse into truncate|invalidate pages

A single open O_TRUNC on a file dirty pages would

	-> truncate
		-> put_wrbuffer_refs
			-> check_caps
				-> invalidate ... and deadlock

So, do not invalidate here if we have a pending truncate (which
remains elevated until after the truncate finishes).

diff --git a/src/kernel/caps.c b/src/kernel/caps.c
index 80772cfdb5dcdce4e99d66e552c75d1c51fa3ca8..723a6495b5d933111ee2acbf4c9330b98aed5ebb 100644 (file)
--- a/src/kernel/caps.c
+++ b/src/kernel/caps.c
@@ -1348,6 +1348,7 @@ retry_locked:
            ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
            ci->i_rdcache_gen &&                     /* may have cached pages */
            file_wanted == 0 &&                      /* no open files */
+           !ci->i_truncate_pending &&
            !tried_invalidate) {
                u32 invalidating_gen = ci->i_rdcache_gen;
                int ret;