Date: Thu, 21 May 2009 15:29:57 +0200 From: Attilio Rao <attilio@freebsd.org> To: Kostik Belousov <kostikbel@gmail.com> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r192535 - head/sys/kern Message-ID: <3bbf2fe10905210629p46c7a204v6863aaba77354462@mail.gmail.com> In-Reply-To: <20090521132641.GJ1927@deviant.kiev.zoral.com.ua> References: <200905211322.n4LDM73t067924@svn.freebsd.org> <20090521132641.GJ1927@deviant.kiev.zoral.com.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
2009/5/21 Kostik Belousov <kostikbel@gmail.com>: > On Thu, May 21, 2009 at 01:22:07PM +0000, Attilio Rao wrote: >> Author: attilio >> Date: Thu May 21 13:22:07 2009 >> New Revision: 192535 >> URL: http://svn.freebsd.org/changeset/base/192535 >> >> Log: >> Move the M_WAITOK flag in notify() into an M_NOWAIT one in order to match >> the behaviour alredy present with the further malloc() call in >> devctl_notify(). >> This fixes a bug in the CAM layer where the camisr handler finished to >> call camperiphfree() (and subsequently destroy_dev() resulting in a new >> dev notify) while the xpt lock is held. > This is wrong. You cannot call destroy_dev() while holding any mutex. > Taking this into account, it makes no sense to use M_NOWAIT in notify(). As long as devctl_notify() also calls M_NOWAIT and if not available skips "silently" it just does the same thing, I think this approach is more consistent. It remains, though, the fact to fix CAM when calling destroy_dev(). Maybe we should add a witness_warn() there? Thanks, Attilio -- Peace can only be achieved by understanding - A. Einstein
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3bbf2fe10905210629p46c7a204v6863aaba77354462>