From patchwork Mon May 20 12:50:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 10951037 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4762417E0 for ; Mon, 20 May 2019 12:52:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 35DD0284ED for ; Mon, 20 May 2019 12:52:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 23C5028686; Mon, 20 May 2019 12:52:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4EFB828686 for ; Mon, 20 May 2019 12:52:10 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id CCAF021F7ED; Mon, 20 May 2019 05:51:46 -0700 (PDT) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from smtp4.ccs.ornl.gov (smtp4.ccs.ornl.gov [160.91.203.40]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id C3D3521F300 for ; Mon, 20 May 2019 05:51:18 -0700 (PDT) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp4.ccs.ornl.gov (Postfix) with ESMTP id 674E91005198; Mon, 20 May 2019 08:51:13 -0400 (EDT) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 61AF12BA; Mon, 20 May 2019 08:51:13 -0400 (EDT) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Mon, 20 May 2019 08:50:52 -0400 Message-Id: <1558356671-29599-11-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1558356671-29599-1-git-send-email-jsimmons@infradead.org> References: <1558356671-29599-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH v2 10/29] lustre: obd_type: discard obd_type_lock X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: NeilBrown This lock is only used to protect typ_refcnt, so change that to an atomic_t and discard the lock. The lock also covers calls to try_module_get and module_put, but this serves no purpose as it does not prevent the module from being unloaded. Finally, the return value for the call to try_module_get is ignored, which is not safe. Signed-off-by: NeilBrown --- fs/lustre/include/obd.h | 3 +-- fs/lustre/include/obd_class.h | 1 - fs/lustre/mdc/mdc_request.c | 2 +- fs/lustre/mgc/mgc_request.c | 7 ------- fs/lustre/obdclass/genops.c | 29 ++++++++++++++--------------- fs/lustre/obdclass/lu_object.c | 2 +- fs/lustre/obdclass/obd_config.c | 19 ------------------- 7 files changed, 17 insertions(+), 46 deletions(-) diff --git a/fs/lustre/include/obd.h b/fs/lustre/include/obd.h index 4c58b91..61fb815 100644 --- a/fs/lustre/include/obd.h +++ b/fs/lustre/include/obd.h @@ -102,9 +102,8 @@ struct obd_type { struct obd_ops *typ_dt_ops; struct md_ops *typ_md_ops; struct dentry *typ_debugfs_entry; - int typ_refcnt; + atomic_t typ_refcnt; struct lu_device_type *typ_lu; - spinlock_t obd_type_lock; struct kobject typ_kobj; }; #define typ_name typ_kobj.name diff --git a/fs/lustre/include/obd_class.h b/fs/lustre/include/obd_class.h index 742cb9a4..a853ed5 100644 --- a/fs/lustre/include/obd_class.h +++ b/fs/lustre/include/obd_class.h @@ -210,7 +210,6 @@ struct lustre_profile { struct lustre_profile *class_get_profile(const char *prof); void class_del_profile(const char *prof); void class_put_profile(struct lustre_profile *lprof); -void class_del_profiles(void); #if LUSTRE_TRACKS_LOCK_EXP_REFS diff --git a/fs/lustre/mdc/mdc_request.c b/fs/lustre/mdc/mdc_request.c index bc764f9..705a4e3 100644 --- a/fs/lustre/mdc/mdc_request.c +++ b/fs/lustre/mdc/mdc_request.c @@ -2542,7 +2542,7 @@ static int mdc_init_ea_size(struct obd_export *exp, u32 easize, u32 def_easize) static int mdc_precleanup(struct obd_device *obd) { /* Failsafe, ok if racy */ - if (obd->obd_type->typ_refcnt <= 1) + if (atomic_read(&obd->obd_type->typ_refcnt) <= 1) libcfs_kkuc_group_rem(0, KUC_GRP_HSM); mdc_changelog_cdev_finish(obd); diff --git a/fs/lustre/mgc/mgc_request.c b/fs/lustre/mgc/mgc_request.c index 84ba6d0..d8be54d 100644 --- a/fs/lustre/mgc/mgc_request.c +++ b/fs/lustre/mgc/mgc_request.c @@ -712,13 +712,6 @@ static int mgc_precleanup(struct obd_device *obd) static int mgc_cleanup(struct obd_device *obd) { - /* COMPAT_146 - old config logs may have added profiles we don't - * know about - */ - if (obd->obd_type->typ_refcnt <= 1) - /* Only for the last mgc */ - class_del_profiles(); - lprocfs_obd_cleanup(obd); ptlrpcd_decref(); diff --git a/fs/lustre/obdclass/genops.c b/fs/lustre/obdclass/genops.c index 3f46298..9c9ad9c 100644 --- a/fs/lustre/obdclass/genops.c +++ b/fs/lustre/obdclass/genops.c @@ -113,15 +113,17 @@ static struct obd_type *class_get_type(const char *name) } } if (type) { - spin_lock(&type->obd_type_lock); - type->typ_refcnt++; - try_module_get(type->typ_dt_ops->owner); - spin_unlock(&type->obd_type_lock); - /* class_search_type() returned a counted reference, - * but we don't need that count any more as - * we have one through typ_refcnt. - */ - kobject_put(&type->typ_kobj); + if (try_module_get(type->typ_dt_ops->owner)) { + atomic_inc(&type->typ_refcnt); + /* class_search_type() returned a counted reference, + * but we don't need that count any more as + * we have one through typ_refcnt. + */ + kobject_put(&type->typ_kobj); + } else { + kobject_put(&type->typ_kobj); + type = NULL; + } } return type; } @@ -129,10 +131,8 @@ static struct obd_type *class_get_type(const char *name) void class_put_type(struct obd_type *type) { LASSERT(type); - spin_lock(&type->obd_type_lock); - type->typ_refcnt--; module_put(type->typ_dt_ops->owner); - spin_unlock(&type->obd_type_lock); + atomic_dec(&type->typ_refcnt); } static void class_sysfs_release(struct kobject *kobj) @@ -193,7 +193,6 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops, /* md_ops is optional */ if (md_ops) *type->typ_md_ops = *md_ops; - spin_lock_init(&type->obd_type_lock); if (ldt) { type->typ_lu = ldt; @@ -220,8 +219,8 @@ int class_unregister_type(const char *name) return -EINVAL; } - if (type->typ_refcnt) { - CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt); + if (atomic_read(&type->typ_refcnt)) { + CERROR("type %s has refcount (%d)\n", name, atomic_read(&type->typ_refcnt)); /* This is a bad situation, let's make the best of it */ /* Remove ops, but leave the name for debugging */ kfree(type->typ_dt_ops); diff --git a/fs/lustre/obdclass/lu_object.c b/fs/lustre/obdclass/lu_object.c index 9c872db..770cc1b 100644 --- a/fs/lustre/obdclass/lu_object.c +++ b/fs/lustre/obdclass/lu_object.c @@ -1267,7 +1267,7 @@ void lu_stack_fini(const struct lu_env *env, struct lu_device *top) next = ldt->ldt_ops->ldto_device_free(env, scan); type = ldt->ldt_obd_type; if (type) { - type->typ_refcnt--; + atomic_dec(&type->typ_refcnt); class_put_type(type); } } diff --git a/fs/lustre/obdclass/obd_config.c b/fs/lustre/obdclass/obd_config.c index 0cdadea4..0da69f6 100644 --- a/fs/lustre/obdclass/obd_config.c +++ b/fs/lustre/obdclass/obd_config.c @@ -743,25 +743,6 @@ void class_put_profile(struct lustre_profile *lprof) } EXPORT_SYMBOL(class_put_profile); -/* COMPAT_146 */ -void class_del_profiles(void) -{ - struct lustre_profile *lprof, *n; - - spin_lock(&lustre_profile_list_lock); - list_for_each_entry_safe(lprof, n, &lustre_profile_list, lp_list) { - list_del(&lprof->lp_list); - lprof->lp_list_deleted = true; - spin_unlock(&lustre_profile_list_lock); - - class_put_profile(lprof); - - spin_lock(&lustre_profile_list_lock); - } - spin_unlock(&lustre_profile_list_lock); -} -EXPORT_SYMBOL(class_del_profiles); - /* We can't call lquota_process_config directly because * it lives in a module that must be loaded after this one. */