svn commit: r360065 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Sat Apr 18 03:07:18 2020
New Revision: 360065
URL: https://svnweb.freebsd.org/changeset/base/360065

Log:
  The pa argument for sendfile_iodone() is not necessary a slice of sfio->pa.
  
  It is true for zfs, but it is not for e.g. vnode or buffer pagers.
  When fixing bogus pages, fix them in both places.  Rely on the fact
  that pa[0] must have been invalid so it cannot be bogus.
  
  Reported and tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks

Modified:
  head/sys/kern/kern_sendfile.c

Modified: head/sys/kern/kern_sendfile.c
==============================================================================
--- head/sys/kern/kern_sendfile.c	Sat Apr 18 02:53:19 2020	(r360064)
+++ head/sys/kern/kern_sendfile.c	Sat Apr 18 03:07:18 2020	(r360065)
@@ -295,10 +295,12 @@ sendfile_iodone(void *arg, vm_page_t *pa, int count, i
 		 * unbusied the swapped-in pages, they can become
 		 * invalid under us.
 		 */
+		MPASS(count == 0 || pa[0] != bogus_page);
 		for (i = 0; i < count; i++) {
 			if (pa[i] == bogus_page) {
-				pa[i] = vm_page_relookup(sfio->obj,
-				    sfio->pindex0 + i + (pa - sfio->pa));
+				sfio->pa[(pa[0]->pindex - sfio->pindex0) + i] =
+				    pa[i] = vm_page_relookup(sfio->obj,
+				    pa[0]->pindex + i);
 				KASSERT(pa[i] != NULL,
 				    ("%s: page %p[%d] disappeared",
 				    __func__, pa, i));