Date: Mon, 25 Jan 2016 09:26:24 +0000 (UTC) From: Steven Hartland <smh@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r294708 - stable/10/sys/dev/iscsi Message-ID: <201601250926.u0P9QODW026534@repo.freebsd.org>
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Author: smh Date: Mon Jan 25 09:26:23 2016 New Revision: 294708 URL: https://svnweb.freebsd.org/changeset/base/294708 Log: MFC r291911, r293659: Fix panic on shutdown due to iscsi event priority. Close iSCSI sessions on shutdown. Sponsored by: Multiplay Modified: stable/10/sys/dev/iscsi/iscsi.c stable/10/sys/dev/iscsi/iscsi.h Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/dev/iscsi/iscsi.c ============================================================================== --- stable/10/sys/dev/iscsi/iscsi.c Mon Jan 25 08:19:16 2016 (r294707) +++ stable/10/sys/dev/iscsi/iscsi.c Mon Jan 25 09:26:23 2016 (r294708) @@ -102,6 +102,9 @@ static int fail_on_disconnection = 0; TUNABLE_INT("kern.iscsi.fail_on_disconnection", &fail_on_disconnection); SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN, &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure"); +static int fail_on_shutdown = 1; +SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_shutdown, CTLFLAG_RWTUN, + &fail_on_shutdown, 0, "Fail disconnected sessions on shutdown"); static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator"); static uma_zone_t iscsi_outstanding_zone; @@ -421,8 +424,6 @@ iscsi_maintenance_thread_terminate(struc sc = is->is_softc; sx_xlock(&sc->sc_lock); - TAILQ_REMOVE(&sc->sc_sessions, is, is_next); - sx_xunlock(&sc->sc_lock); icl_conn_close(is->is_conn); callout_drain(&is->is_callout); @@ -454,6 +455,9 @@ iscsi_maintenance_thread_terminate(struc #ifdef ICL_KERNEL_PROXY cv_destroy(&is->is_login_cv); #endif + TAILQ_REMOVE(&sc->sc_sessions, is, is_next); + sx_xunlock(&sc->sc_lock); + ISCSI_SESSION_DEBUG(is, "terminated"); free(is, M_ISCSI); @@ -477,12 +481,7 @@ iscsi_maintenance_thread(void *arg) STAILQ_EMPTY(&is->is_postponed)) cv_wait(&is->is_maintenance_cv, &is->is_lock); - if (is->is_reconnecting) { - ISCSI_SESSION_UNLOCK(is); - iscsi_maintenance_thread_reconnect(is); - continue; - } - + /* Terminate supersedes reconnect. */ if (is->is_terminating) { ISCSI_SESSION_UNLOCK(is); iscsi_maintenance_thread_terminate(is); @@ -490,6 +489,12 @@ iscsi_maintenance_thread(void *arg) return; } + if (is->is_reconnecting) { + ISCSI_SESSION_UNLOCK(is); + iscsi_maintenance_thread_reconnect(is); + continue; + } + iscsi_session_send_postponed(is); ISCSI_SESSION_UNLOCK(is); } @@ -609,6 +614,11 @@ iscsi_callout(void *context) return; out: + if (is->is_terminating) { + ISCSI_SESSION_UNLOCK(is); + return; + } + ISCSI_SESSION_UNLOCK(is); if (reconnect_needed) @@ -2320,30 +2330,62 @@ iscsi_poll(struct cam_sim *sim) } static void -iscsi_shutdown(struct iscsi_softc *sc) +iscsi_terminate_sessions(struct iscsi_softc *sc) { struct iscsi_session *is; - /* - * Trying to reconnect during system shutdown would lead to hang. - */ - fail_on_disconnection = 1; + sx_slock(&sc->sc_lock); + TAILQ_FOREACH(is, &sc->sc_sessions, is_next) + iscsi_session_terminate(is); + while(!TAILQ_EMPTY(&sc->sc_sessions)) { + ISCSI_DEBUG("waiting for sessions to terminate"); + cv_wait(&sc->sc_cv, &sc->sc_lock); + } + ISCSI_DEBUG("all sessions terminated"); + sx_sunlock(&sc->sc_lock); +} + +static void +iscsi_shutdown_pre(struct iscsi_softc *sc) +{ + struct iscsi_session *is; + + if (!fail_on_shutdown) + return; /* * If we have any sessions waiting for reconnection, request * maintenance thread to fail them immediately instead of waiting * for reconnect timeout. + * + * This prevents LUNs with mounted filesystems that are supported + * by disconnected iSCSI sessions from hanging, however it will + * fail all queued BIOs. */ + ISCSI_DEBUG("forcing failing all disconnected sessions due to shutdown"); + + fail_on_disconnection = 1; + sx_slock(&sc->sc_lock); TAILQ_FOREACH(is, &sc->sc_sessions, is_next) { ISCSI_SESSION_LOCK(is); - if (is->is_waiting_for_iscsid) + if (!is->is_connected) { + ISCSI_SESSION_DEBUG(is, "force failing disconnected session early"); iscsi_session_reconnect(is); + } ISCSI_SESSION_UNLOCK(is); } sx_sunlock(&sc->sc_lock); } +static void +iscsi_shutdown_post(struct iscsi_softc *sc) +{ + + ISCSI_DEBUG("removing all sessions due to shutdown"); + iscsi_terminate_sessions(sc); +} + static int iscsi_load(void) { @@ -2366,8 +2408,16 @@ iscsi_load(void) } sc->sc_cdev->si_drv1 = sc; - sc->sc_shutdown_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync, - iscsi_shutdown, sc, SHUTDOWN_PRI_FIRST); + sc->sc_shutdown_pre_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync, + iscsi_shutdown_pre, sc, SHUTDOWN_PRI_FIRST); + /* + * shutdown_post_sync needs to run after filesystem shutdown and before + * CAM shutdown - otherwise when rebooting with an iSCSI session that is + * disconnected but has outstanding requests, dashutdown() will hang on + * cam_periph_runccb(). + */ + sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync, + iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1); return (0); } @@ -2375,7 +2425,6 @@ iscsi_load(void) static int iscsi_unload(void) { - struct iscsi_session *is, *tmp; if (sc->sc_cdev != NULL) { ISCSI_DEBUG("removing device node"); @@ -2383,18 +2432,12 @@ iscsi_unload(void) ISCSI_DEBUG("device node removed"); } - if (sc->sc_shutdown_eh != NULL) - EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_eh); + if (sc->sc_shutdown_pre_eh != NULL) + EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_pre_eh); + if (sc->sc_shutdown_post_eh != NULL) + EVENTHANDLER_DEREGISTER(shutdown_post_sync, sc->sc_shutdown_post_eh); - sx_slock(&sc->sc_lock); - TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) - iscsi_session_terminate(is); - while(!TAILQ_EMPTY(&sc->sc_sessions)) { - ISCSI_DEBUG("waiting for sessions to terminate"); - cv_wait(&sc->sc_cv, &sc->sc_lock); - } - ISCSI_DEBUG("all sessions terminated"); - sx_sunlock(&sc->sc_lock); + iscsi_terminate_sessions(sc); uma_zdestroy(iscsi_outstanding_zone); sx_destroy(&sc->sc_lock); Modified: stable/10/sys/dev/iscsi/iscsi.h ============================================================================== --- stable/10/sys/dev/iscsi/iscsi.h Mon Jan 25 08:19:16 2016 (r294707) +++ stable/10/sys/dev/iscsi/iscsi.h Mon Jan 25 09:26:23 2016 (r294708) @@ -130,7 +130,8 @@ struct iscsi_softc { TAILQ_HEAD(, iscsi_session) sc_sessions; struct cv sc_cv; unsigned int sc_last_session_id; - eventhandler_tag sc_shutdown_eh; + eventhandler_tag sc_shutdown_pre_eh; + eventhandler_tag sc_shutdown_post_eh; }; #endif /* !ISCSI_H */
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