svn commit: r356038 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Mon Dec 23 20:15:19 2019
New Revision: 356038
URL: https://svnweb.freebsd.org/changeset/base/356038

Log:
  Do not use waitable allocation of pbuf when creating cluster for write.
  
  Previously just ensuring that we do not sleep when clustering for
  md(4) vnode was enough.  Now, with the switch of the pbuf allocator to
  uma and completely broken per-subsystem pbuf limits, it might cause
  unbounded sleep even for non-md(4) vnodes.
  
  Reported and tested by:	pho
  Reviewed by:	markj
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D22899

Modified:
  head/sys/kern/vfs_cluster.c

Modified: head/sys/kern/vfs_cluster.c
==============================================================================
--- head/sys/kern/vfs_cluster.c	Mon Dec 23 16:34:39 2019	(r356037)
+++ head/sys/kern/vfs_cluster.c	Mon Dec 23 20:15:19 2019	(r356038)
@@ -865,8 +865,7 @@ cluster_wbuild(struct vnode *vp, long size, daddr_t st
 		  (tbp->b_bcount != tbp->b_bufsize) ||
 		  (tbp->b_bcount != size) ||
 		  (len == 1) ||
-		  ((bp = uma_zalloc(cluster_pbuf_zone,
-		  (vp->v_vflag & VV_MD) != 0 ? M_NOWAIT : M_WAITOK)) == NULL)) {
+		  ((bp = uma_zalloc(cluster_pbuf_zone, M_NOWAIT)) == NULL)) {
 			totalwritten += tbp->b_bufsize;
 			bawrite(tbp);
 			++start_lbn;