Date: Tue, 6 Dec 2011 20:57:02 +0100 From: Ed Schouten <ed@80386.nl> To: scsi@freebsd.org Subject: Use cdevpriv in targ(4) Message-ID: <20111206195702.GF59489@hoeg.nl>
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--9sSKoi6Rw660DLir Content-Type: multipart/mixed; boundary="bO4vSxwwZtUjUWHo" Content-Disposition: inline --bO4vSxwwZtUjUWHo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello all, I sent this patch to mjacob@ previously, but he redirected me to this list, so here it goes. The other day I spent some time grepping through character device/devfs code and I noticed we can make the targ(4) driver a lot more beautiful if we simply change the code to use a single device node (/dev/targ) and use per-file descriptor data, instead of hacking around with clonelists. As I have no idea how to actually test and use targ(4), so is there a way I can persuade any of you to test/debug this patch for me? Thanks, --=20 Ed Schouten <ed@80386.nl> WWW: http://80386.nl/ --bO4vSxwwZtUjUWHo Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="targ.diff" Content-Transfer-Encoding: quoted-printable Index: sys/cam/scsi/scsi_target.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- sys/cam/scsi/scsi_target.c (revision 228283) +++ sys/cam/scsi/scsi_target.c (working copy) @@ -96,12 +96,9 @@ targ_state state; struct selinfo read_select; struct devstat device_stats; - struct callout destroy_dev_callout; - struct mtx destroy_mtx; }; =20 static d_open_t targopen; -static d_close_t targclose; static d_read_t targread; static d_write_t targwrite; static d_ioctl_t targioctl; @@ -119,7 +116,6 @@ .d_version =3D D_VERSION, .d_flags =3D D_NEEDGIANT, .d_open =3D targopen, - .d_close =3D targclose, .d_read =3D targread, .d_write =3D targwrite, .d_ioctl =3D targioctl, @@ -152,15 +148,12 @@ static struct targ_cmd_descr * targgetdescr(struct targ_softc *softc); static periph_init_t targinit; -static void targclone(void *arg, struct ucred *cred, char *name, - int namelen, struct cdev **dev); static void targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg); static void abort_all_pending(struct targ_softc *softc); static void notify_user(struct targ_softc *softc); static int targcamstatus(cam_status status); static size_t targccblen(xpt_opcode func_code); -static void targdestroy(void *); =20 static struct periph_driver targdriver =3D { @@ -171,66 +164,18 @@ =20 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data"); =20 -/* - * Create softc and initialize it. Only one proc can open each targ device. - * There is no locking here because a periph doesn't get created until an - * ioctl is issued to do so, and that can't happen until this method retur= ns. - */ -static int -targopen(struct cdev *dev, int flags, int fmt, struct thread *td) +/* Disable LUN if enabled and teardown softc */ +static void +targcdevdtor(void *data) { struct targ_softc *softc; + struct cam_periph *periph; =20 - if (dev->si_drv1 !=3D 0) { - return (EBUSY); - } -=09 - /* Mark device busy before any potentially blocking operations */ - dev->si_drv1 =3D (void *)~0; - - /* Create the targ device, allocate its softc, initialize it */ - if ((dev->si_flags & SI_NAMED) =3D=3D 0) { - make_dev(&targ_cdevsw, dev2unit(dev), UID_ROOT, GID_WHEEL, 0600, - "targ%d", dev2unit(dev)); - } - softc =3D malloc(sizeof(*softc), M_TARG, - M_WAITOK | M_ZERO); - dev->si_drv1 =3D softc; - softc->state =3D TARG_STATE_OPENED; - softc->periph =3D NULL; - softc->path =3D NULL; - - TAILQ_INIT(&softc->pending_ccb_queue); - TAILQ_INIT(&softc->work_queue); - TAILQ_INIT(&softc->abort_queue); - TAILQ_INIT(&softc->user_ccb_queue); - knlist_init_mtx(&softc->read_select.si_note, NULL); - - return (0); -} - -/* Disable LUN if enabled and teardown softc */ -static int -targclose(struct cdev *dev, int flag, int fmt, struct thread *td) -{ - struct targ_softc *softc; - struct cam_periph *periph; - int error; - - softc =3D (struct targ_softc *)dev->si_drv1; - mtx_init(&softc->destroy_mtx, "targ_destroy", "SCSI Target dev destroy", = MTX_DEF); - callout_init_mtx(&softc->destroy_dev_callout, &softc->destroy_mtx, CALLO= UT_RETURNUNLOCKED); + softc =3D data; if (softc->periph =3D=3D NULL) { -#if 0 - destroy_dev(dev); + printf("%s: destroying non-enabled target\n", __func__); free(softc, M_TARG); -#endif - printf("%s: destroying non-enabled target\n", __func__); - mtx_lock(&softc->destroy_mtx); - callout_reset(&softc->destroy_dev_callout, hz / 2, - (void *)targdestroy, (void *)dev); - mtx_unlock(&softc->destroy_mtx); - return (0); + return; } =20 /* @@ -240,25 +185,41 @@ periph =3D softc->periph; cam_periph_acquire(periph); cam_periph_lock(periph); - error =3D targdisable(softc); + (void)targdisable(softc); if (softc->periph !=3D NULL) { cam_periph_invalidate(softc->periph); softc->periph =3D NULL; } cam_periph_unlock(periph); cam_periph_release(periph); - -#if 0 - destroy_dev(dev); free(softc, M_TARG); -#endif +} =20 - printf("%s: close finished error(%d)\n", __func__, error); - mtx_lock(&softc->destroy_mtx); - callout_reset(&softc->destroy_dev_callout, hz / 2, - (void *)targdestroy, (void *)dev); - mtx_unlock(&softc->destroy_mtx); - return (error); +/* + * Create softc and initialize it. There is no locking here because a + * periph doesn't get created until an ioctl is issued to do so, and + * that can't happen until this method returns. + */ +static int +targopen(struct cdev *dev, int flags, int fmt, struct thread *td) +{ + struct targ_softc *softc; + + /* Allocate its softc, initialize it */ + softc =3D malloc(sizeof(*softc), M_TARG, + M_WAITOK | M_ZERO); + softc->state =3D TARG_STATE_OPENED; + softc->periph =3D NULL; + softc->path =3D NULL; + + TAILQ_INIT(&softc->pending_ccb_queue); + TAILQ_INIT(&softc->work_queue); + TAILQ_INIT(&softc->abort_queue); + TAILQ_INIT(&softc->user_ccb_queue); + knlist_init_mtx(&softc->read_select.si_note, NULL); + + devfs_set_cdevpriv(softc, targcdevdtor); + return (0); } =20 /* Enable/disable LUNs, set debugging level */ @@ -268,7 +229,7 @@ struct targ_softc *softc; cam_status status; =20 - softc =3D (struct targ_softc *)dev->si_drv1; + devfs_get_cdevpriv((void **)&softc); =20 switch (cmd) { case TARGIOCENABLE: @@ -346,7 +307,7 @@ struct targ_softc *softc; int revents; =20 - softc =3D (struct targ_softc *)dev->si_drv1; + devfs_get_cdevpriv((void **)&softc); =20 /* Poll for write() is always ok. */ revents =3D poll_events & (POLLOUT | POLLWRNORM); @@ -371,7 +332,7 @@ { struct targ_softc *softc; =20 - softc =3D (struct targ_softc *)dev->si_drv1; + devfs_get_cdevpriv((void **)&softc); kn->kn_hook =3D (caddr_t)softc; kn->kn_fop =3D &targread_filtops; knlist_add(&softc->read_select.si_note, kn, 0); @@ -572,7 +533,7 @@ int write_len, error; int func_code, priority; =20 - softc =3D (struct targ_softc *)dev->si_drv1; + devfs_get_cdevpriv((void **)&softc); write_len =3D error =3D 0; CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("write - uio_resid %zd\n", uio->uio_resid)); @@ -866,7 +827,7 @@ =20 error =3D 0; read_len =3D 0; - softc =3D (struct targ_softc *)dev->si_drv1; + devfs_get_cdevpriv((void **)&softc); user_queue =3D &softc->user_ccb_queue; abort_queue =3D &softc->abort_queue; CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n")); @@ -1051,23 +1012,11 @@ static void targinit(void) { - EVENTHANDLER_REGISTER(dev_clone, targclone, 0, 1000); -} + struct cdev *dev; =20 -static void -targclone(void *arg, struct ucred *cred, char *name, int namelen, - struct cdev **dev) -{ - int u; - - if (*dev !=3D NULL) - return; - if (dev_stdclone(name, NULL, "targ", &u) !=3D 1) - return; - *dev =3D make_dev(&targ_cdevsw, u, UID_ROOT, GID_WHEEL, - 0600, "targ%d", u); - dev_ref(*dev); - (*dev)->si_flags |=3D SI_CHEAPCLONE; + /* Add symbolic link to targ0 for compatibility. */ + dev =3D make_dev(&targ_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "targ"); + make_dev_alias(dev, "targ0"); } =20 static void @@ -1221,25 +1170,3 @@ =20 return (len); } - -/* - * work around to destroy targ device - * outside of targclose - */ -static void -targdestroy(void *dev) -{ - struct cdev *device =3D (struct cdev *)dev; - struct targ_softc *softc =3D (struct targ_softc *)device->si_drv1; - -#if 0 - callout_stop(&softc->destroy_dev_callout); -#endif - - mtx_unlock(&softc->destroy_mtx); - mtx_destroy(&softc->destroy_mtx); - free(softc, M_TARG); - device->si_drv1 =3D 0; - destroy_dev(device); - printf("%s: destroyed dev\n", __func__); -} --bO4vSxwwZtUjUWHo-- --9sSKoi6Rw660DLir Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iQIcBAEBAgAGBQJO3nOOAAoJEG5e2P40kaK77/8QAKSa9NSr8zLik8pk40h5jPgu wTgN6HCDx0pmVAmLWIMavTdF4hI8b17KMPPXHLSjq2f906LJKN4XUU9qsddbSWWo SICc5gHZbM4DOAQ3x7PIhgNP8tYvufcHlaxdPCg3jr1N3RG6qCCwXxEgiTvDTY7a ii+oupE7QV/rIy8qyGdm4nGg5RQ5qZZ1L7Jv1c3RTk/pwIx8Yd9kc4iZc3Bw7V3P NyrHgxk7lZuIHj/LYT6l5fc6XRdwILgD94kgPIRb9lbZLhgP7UAHfXaDK2YWgMVO BBEtkIE58/d+9SinxMt6SpzuI+Fiy5kgFWTa3aJS3wL/ezH1DldovaXxg88D9ANm 6Tnp09DIap/vnnmJsI1N7jkVm0axxAr7i/bZr7kW5Nk9aCBII07AZ3zhg+fjuMPT Kn/Z61UornBZSN9li6KredCEpiXD9HlKOpdkSyEAlF/2EUD4IiW6KhlFq8a4ikik zujBIYZ49b1dbircZWqD1plWiPX4XewTro0c8J7aY2muLUJiOT3S+BzJnXE2FWCM U41RQ2/BdtE4G6H10jCsRNGFcgHgfE8S6iXtpILtpfBO5z2Nt7F3aZ4WQVm0rRd7 S088mi93Qj7yGu7fzj/fbVRUvHXGlSjuksquKt27UtisYmU7ngkFCbu+xPUte2Yt y/0oShRgRG5n3wiD0Lrp =f6Rg -----END PGP SIGNATURE----- --9sSKoi6Rw660DLir--
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