Date: Mon, 4 May 2015 12:54:59 +0300 From: Gleb Smirnoff <glebius@FreeBSD.org> To: Julian Elischer <julian@freebsd.org> Cc: Konstantin Belousov <kostikbel@gmail.com>, alc@FreeBSD.org, arch@FreeBSD.org Subject: Re: more strict KPI for vm_pager_get_pages() Message-ID: <20150504095459.GI34544@glebius.int.ru> In-Reply-To: <554740EF.7030808@freebsd.org> References: <20150430142408.GS546@nginx.com> <20150504082426.GC2390@kib.kiev.ua> <554740EF.7030808@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, May 04, 2015 at 05:50:39PM +0800, Julian Elischer wrote: J> > IMO, the response from vm_pager_haspages() is only advisory, since J> > filesystem might not control the external entities which are the source J> > of the required data. J> J> Also since the backing object is not locked, a truncate() may be performed J> between the operations making the prior return information invalid. J> Certainly in remote filesystems, possibly on local ones too. Of course, the object shouldn't be unlocked between vm_pager_haspage() and vm_pager_get_pages(). All current consumers do not unlock. -- Totus tuus, Glebius.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20150504095459.GI34544>