Date: Sat, 31 Jul 2021 00:21:34 GMT From: Warner Losh <imp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 5b59c5186902 - stable/12 - nvme: use config_intrhook_drain to avoid removable card races Message-ID: <202107310021.16V0LYrt052168@gitrepo.freebsd.org>
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The branch stable/12 has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=5b59c5186902f8ac402b89796567fa630abb10c2 commit 5b59c5186902f8ac402b89796567fa630abb10c2 Author: Warner Losh <imp@FreeBSD.org> AuthorDate: 2021-03-11 15:42:44 +0000 Commit: Warner Losh <imp@FreeBSD.org> CommitDate: 2021-07-31 00:02:53 +0000 nvme: use config_intrhook_drain to avoid removable card races nvme drives are configured early in boot. However, a number of the configuration steps takes which take a while, so we defer those to a config intrhook that runs before the root filesystem is mounted. At the same time, the PCI hot plug wakes up and tests the status of the card. It may decide that the card has gone away and deletes the child. As part of that process nvme_detach is called. If this call happens after the config_intrhook starts to run, but before it is finished, there's a race where we can tear down the device's soft state while the config_intrhook is still using it. Use the new config_intrhook_drain to disestablish the hook. Either it will be removed w/o running, or the routine will wait for it to finish. This closes the race and allows safe hotplug at any time, even very early in boot. Sponsored by: Netflix, Inc Reviewed by: jhb, mav Differential Revision: https://reviews.freebsd.org/D29006 (cherry picked from commit 8423f5d4c127f18e7500bc455bc7b6b1691385ef) --- sys/dev/nvme/nvme.c | 5 +---- sys/dev/nvme/nvme_ctrlr.c | 2 -- 2 files changed, 1 insertion(+), 6 deletions(-) diff --git a/sys/dev/nvme/nvme.c b/sys/dev/nvme/nvme.c index 8e5bc11b35d4..17ee7b19177d 100644 --- a/sys/dev/nvme/nvme.c +++ b/sys/dev/nvme/nvme.c @@ -144,10 +144,7 @@ nvme_detach(device_t dev) { struct nvme_controller *ctrlr = DEVICE2SOFTC(dev); - if (ctrlr->config_hook.ich_arg != NULL) { - config_intrhook_disestablish(&ctrlr->config_hook); - ctrlr->config_hook.ich_arg = NULL; - } + config_intrhook_drain(&ctrlr->config_hook); nvme_ctrlr_destruct(ctrlr, dev); return (0); diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c index d4d472878b82..007e0758023a 100644 --- a/sys/dev/nvme/nvme_ctrlr.c +++ b/sys/dev/nvme/nvme_ctrlr.c @@ -1135,7 +1135,6 @@ nvme_ctrlr_start_config_hook(void *arg) fail: nvme_ctrlr_fail(ctrlr); config_intrhook_disestablish(&ctrlr->config_hook); - ctrlr->config_hook.ich_arg = NULL; return; } @@ -1154,7 +1153,6 @@ fail: nvme_sysctl_initialize_ctrlr(ctrlr); config_intrhook_disestablish(&ctrlr->config_hook); - ctrlr->config_hook.ich_arg = NULL; ctrlr->is_initialized = 1; nvme_notify_new_controller(ctrlr);
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