Date: Fri, 25 Apr 2008 12:50:09 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Andriy Gapon <avg@icyb.net.ua> Cc: freebsd-hackers@freebsd.org Subject: Re: devctl (alike?) for devfs Message-ID: <20080425095009.GD18958@deviant.kiev.zoral.com.ua> In-Reply-To: <4810FD1E.70602@icyb.net.ua> References: <480E4269.2090604@icyb.net.ua> <480FBAB9.1000904@icyb.net.ua> <48103F36.6060707@icyb.net.ua> <200804240811.26183.jhb@freebsd.org> <4810FD1E.70602@icyb.net.ua>
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--Xc2zRdLclVh020+J Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 25, 2008 at 12:35:26AM +0300, Andriy Gapon wrote: >=20 > I decided to do it in devfs_devs.c because there are less entry points > there and the code is much simpler (you know: aliases, clones). > I also had to add !cold condition, because apparently we have devices > created so early in the boot, that devctl is not ready to handle a > notification. My system hanged after only getting to the following line > in verbose boot: > ULE: setup cpu 0 > However it is possible that it did something wrong - at that time I had > devctl calls in kern_conf. >=20 > I guess this also should be OK from the user perspective because they > would be interested in device events after a system is booted and devd > is running. >=20 > Here is a log of devd started with -dD flags in single-user mode, then I > attached and later detached an external hdd: > http://www.icyb.net.ua/~avg/devd.log.gz > Search for DEVFS for interesting lines. >=20 > --=20 > Andriy Gapon > diff --git a/sys/fs/devfs/devfs_devs.c b/sys/fs/devfs/devfs_devs.c > index ca5c2de..3556799 100644 > --- a/sys/fs/devfs/devfs_devs.c > +++ b/sys/fs/devfs/devfs_devs.c > @@ -33,6 +33,7 @@ > #include <sys/param.h> > #include <sys/systm.h> > #include <sys/conf.h> > +#include <sys/bus.h> > #include <sys/dirent.h> > #include <sys/kernel.h> > #include <sys/limits.h> > @@ -518,6 +519,9 @@ devfs_create(struct cdev *dev) > dev_refl(dev); > TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list); > devfs_generation++; > + > + if (!cold) > + devctl_notify("DEVFS", dev->si_name, "ATTACH", NULL); > } > =20 > void > @@ -529,6 +533,9 @@ devfs_destroy(struct cdev *dev) > cdp =3D dev->si_priv; > cdp->cdp_flags &=3D ~CDP_ACTIVE; > devfs_generation++; > + > + if (!cold) > + devctl_notify("DEVFS", dev->si_name, "DETACH", NULL); > } > =20 > static void Did you run this with WITNESS ? You put the whole devctl_notify() call under the dev_mtx. This includes the malloc(), PROC_LOCK() and signalling, and some internal devctl_queue() stuff. This is wrong. --Xc2zRdLclVh020+J Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (FreeBSD) iEYEARECAAYFAkgRqVEACgkQC3+MBN1Mb4hTrgCeLqWrGFHU2nVieITScAHlZL6x f5UAoJ8tOstn8GmRE2XbmmUDv0yeO3lf =9Tr4 -----END PGP SIGNATURE----- --Xc2zRdLclVh020+J--
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