Date: Thu, 23 Mar 2017 07:56:13 +0000 (UTC) From: Andriy Gapon <avg@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: r315831 - stable/10/sys/dev/firewire Message-ID: <201703230756.v2N7uDHr085810@repo.freebsd.org>
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Author: avg Date: Thu Mar 23 07:56:13 2017 New Revision: 315831 URL: https://svnweb.freebsd.org/changeset/base/315831 Log: MFC r314864: firewire/sbp: try to improve locking, plus a few style nits Modified: stable/10/sys/dev/firewire/sbp.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/dev/firewire/sbp.c ============================================================================== --- stable/10/sys/dev/firewire/sbp.c Thu Mar 23 07:56:07 2017 (r315830) +++ stable/10/sys/dev/firewire/sbp.c Thu Mar 23 07:56:13 2017 (r315831) @@ -455,7 +455,6 @@ sbp_alloc_lun(struct sbp_target *target) int maxlun, lun, i; sbp = target->sbp; - SBP_LOCK_ASSERT(sbp); crom_init_context(&cc, target->fwdev->csrrom); /* XXX shoud parse appropriate unit directories only */ maxlun = -1; @@ -588,7 +587,9 @@ END_DEBUG goto next; } callout_init_mtx(&ocb->timer, &sbp->mtx, 0); + SBP_LOCK(sbp); sbp_free_ocb(sdev, ocb); + SBP_UNLOCK(sbp); } next: crom_next(&cc); @@ -718,9 +719,8 @@ END_DEBUG && crom_has_specver((fwdev)->csrrom, CSRVAL_ANSIT10, CSRVAL_T10SBP2)) static void -sbp_probe_target(void *arg) +sbp_probe_target(struct sbp_target *target) { - struct sbp_target *target = (struct sbp_target *)arg; struct sbp_softc *sbp = target->sbp; struct sbp_dev *sdev; int i, alive; @@ -732,8 +732,6 @@ SBP_DEBUG(1) (!alive) ? " not " : ""); END_DEBUG - sbp = target->sbp; - SBP_LOCK_ASSERT(sbp); sbp_alloc_lun(target); /* XXX untimeout mgm_ocb and dequeue */ @@ -749,7 +747,9 @@ END_DEBUG sbp_probe_lun(sdev); sbp_show_sdev_info(sdev); + SBP_LOCK(sbp); sbp_abort_all_ocbs(sdev, CAM_SCSI_BUS_RESET); + SBP_UNLOCK(sbp); switch (sdev->status) { case SBP_DEV_RESET: /* new or revived target */ @@ -804,9 +804,9 @@ SBP_DEBUG(0) printf("sbp_post_busreset\n"); END_DEBUG SBP_LOCK(sbp); - if ((sbp->sim->flags & SIMQ_FREEZED) == 0) { + if ((sbp->flags & SIMQ_FREEZED) == 0) { xpt_freeze_simq(sbp->sim, /*count*/1); - sbp->sim->flags |= SIMQ_FREEZED; + sbp->flags |= SIMQ_FREEZED; } microtime(&sbp->last_busreset); SBP_UNLOCK(sbp); @@ -831,19 +831,15 @@ END_DEBUG sbp_cold --; SBP_LOCK(sbp); -#if 0 - /* - * XXX don't let CAM the bus rest. - * CAM tries to do something with freezed (DEV_RETRY) devices. - */ - xpt_async(AC_BUS_RESET, sbp->path, /*arg*/ NULL); -#endif /* Garbage Collection */ for(i = 0 ; i < SBP_NUM_TARGETS ; i ++){ target = &sbp->targets[i]; + if (target->fwdev == NULL) + continue; + STAILQ_FOREACH(fwdev, &sbp->fd.fc->devices, link) - if (target->fwdev == NULL || target->fwdev == fwdev) + if (target->fwdev == fwdev) break; if (fwdev == NULL) { /* device has removed in lower driver */ @@ -851,6 +847,7 @@ END_DEBUG sbp_free_target(target); } } + /* traverse device list */ STAILQ_FOREACH(fwdev, &sbp->fd.fc->devices, link) { SBP_DEBUG(0) @@ -877,12 +874,24 @@ END_DEBUG continue; } } - sbp_probe_target((void *)target); + + /* + * It is safe to drop the lock here as the target is already + * reserved, so there should be no contenders for it. + * And the target is not yet exposed, so there should not be + * any other accesses to it. + * Finally, the list being iterated is protected somewhere else. + */ + SBP_UNLOCK(sbp); + sbp_probe_target(target); + SBP_LOCK(sbp); if (target->num_lun == 0) sbp_free_target(target); } - xpt_release_simq(sbp->sim, /*run queue*/TRUE); - sbp->sim->flags &= ~SIMQ_FREEZED; + if ((sbp->flags & SIMQ_FREEZED) != 0) { + xpt_release_simq(sbp->sim, /*run queue*/TRUE); + sbp->flags &= ~SIMQ_FREEZED; + } SBP_UNLOCK(sbp); } @@ -989,30 +998,36 @@ sbp_next_dev(struct sbp_target *target, static void sbp_cam_scan_lun(struct cam_periph *periph, union ccb *ccb) { + struct sbp_softc *sbp; struct sbp_target *target; struct sbp_dev *sdev; sdev = (struct sbp_dev *) ccb->ccb_h.ccb_sdev_ptr; target = sdev->target; - SBP_LOCK_ASSERT(target->sbp); + sbp = target->sbp; + SBP_LOCK(sbp); SBP_DEBUG(0) - device_printf(sdev->target->sbp->fd.dev, + device_printf(sbp->fd.dev, "%s:%s\n", __func__, sdev->bustgtlun); END_DEBUG if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) { sdev->status = SBP_DEV_ATTACHED; } else { - device_printf(sdev->target->sbp->fd.dev, + device_printf(sbp->fd.dev, "%s:%s failed\n", __func__, sdev->bustgtlun); } sdev = sbp_next_dev(target, sdev->lun_id + 1); if (sdev == NULL) { + SBP_UNLOCK(sbp); free(ccb, M_SBP); return; } /* reuse ccb */ xpt_setup_ccb(&ccb->ccb_h, sdev->path, SCAN_PRI); ccb->ccb_h.ccb_sdev_ptr = sdev; + ccb->ccb_h.flags |= CAM_DEV_QFREEZE; + SBP_UNLOCK(sbp); + xpt_action(ccb); xpt_release_devq(sdev->path, sdev->freeze, TRUE); sdev->freeze = 1; @@ -1041,6 +1056,8 @@ END_DEBUG printf("sbp_cam_scan_target: malloc failed\n"); return; } + SBP_UNLOCK(target->sbp); + xpt_setup_ccb(&ccb->ccb_h, sdev->path, SCAN_PRI); ccb->ccb_h.func_code = XPT_SCAN_LUN; ccb->ccb_h.cbfcnp = sbp_cam_scan_lun; @@ -1050,6 +1067,8 @@ END_DEBUG /* The scan is in progress now. */ xpt_action(ccb); + + SBP_LOCK(target->sbp); xpt_release_devq(sdev->path, sdev->freeze, TRUE); sdev->freeze = 1; } @@ -2015,8 +2034,8 @@ END_DEBUG sbp->fd.post_explore = sbp_post_explore; if (fc->status != -1) { - sbp_post_busreset((void *)sbp); - sbp_post_explore((void *)sbp); + sbp_post_busreset(sbp); + sbp_post_explore(sbp); } SBP_LOCK(sbp); xpt_async(AC_BUS_RESET, sbp->path, /*arg*/ NULL);
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