Date: Sat, 30 Oct 2010 11:25:05 +0300 From: Andriy Gapon <avg@freebsd.org> To: Artemiev Igor <ai@kliksys.ru> Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org Subject: Re: 8.1-STABLE: zfs and sendfile: problem still exists Message-ID: <4CCBD661.3000204@freebsd.org> In-Reply-To: <4CCBD46E.9030200@icyb.net.ua> References: <3D1C350B94A44E5D95BAA1596D1EBF13@vosz.local> <20101029090417.GA17537@two.kliksys.ru> <4CCABFC2.3040701@icyb.net.ua> <4CCADD37.7000306@icyb.net.ua> <20101029152602.GA18613@two.kliksys.ru> <4CCAF0EB.4080001@icyb.net.ua> <20101029175105.GB18613@two.kliksys.ru> <4CCBD443.7010305@icyb.net.ua> <4CCBD46E.9030200@icyb.net.ua>
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on 30/10/2010 11:16 Andriy Gapon said the following:
> on 30/10/2010 11:16 Andriy Gapon said the following:
>> Or maybe something like the following?
>> It looks a little bit cleaner to me, but still is not perfect, as I have not
>> handled unnecessary busy-ing of the pages where something more lightweight could
>> have sufficed (e.g. wiring and shared busying).
>
> Note: I have only compile tested the patch.
Missed one NULL check.
Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c (revision 214318)
+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c (working copy)
@@ -67,6 +67,7 @@
#include <sys/sf_buf.h>
#include <sys/sched.h>
#include <sys/acl.h>
+#include <vm/vm_pageout.h>
/*
* Programming rules.
@@ -464,7 +465,7 @@
uiomove_fromphys(&m, off, bytes, uio);
VM_OBJECT_LOCK(obj);
vm_page_wakeup(m);
- } else if (m != NULL && uio->uio_segflg == UIO_NOCOPY) {
+ } else if (uio->uio_segflg == UIO_NOCOPY) {
/*
* The code below is here to make sendfile(2) work
* correctly with ZFS. As pointed out by ups@
@@ -474,8 +475,18 @@
*/
KASSERT(off == 0,
("unexpected offset in mappedread for sendfile"));
- if (vm_page_sleep_if_busy(m, FALSE, "zfsmrb"))
+ if (m != NULL && vm_page_sleep_if_busy(m, FALSE, "zfsmrb"))
goto again;
+ if (m == NULL) {
+ m = vm_page_alloc(obj, OFF_TO_IDX(start),
+ VM_ALLOC_NOBUSY | VM_ALLOC_SYSTEM);
+ if (m == NULL) {
+ VM_OBJECT_UNLOCK(obj);
+ VM_WAIT;
+ VM_OBJECT_LOCK(obj);
+ goto again;
+ }
+ }
vm_page_busy(m);
VM_OBJECT_UNLOCK(obj);
if (dirbytes > 0) {
--
Andriy Gapon
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