From nobody Sat May 4 23:41:32 2024 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69E4FC76196 for ; Tue, 28 Mar 2023 08:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231124AbjC1IqS (ORCPT ); Tue, 28 Mar 2023 04:46:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231819AbjC1IqL (ORCPT ); Tue, 28 Mar 2023 04:46:11 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CFC455A1; Tue, 28 Mar 2023 01:46:06 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id F2E521FDA1; Tue, 28 Mar 2023 08:46:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1679993165; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=XkRrVX8XzPB5UHUjHXjJ+xWWlRyOClSfTOm/ZrUGMDw=; b=BXUn2XOtBlkO6BfqJ9xz1Y8JkP8uIsgjzDECMGZ0Jh/UurP91nuLzaw9ZDMKbiiO4tpgKn 48XtNjyA4FGeWwJDGjFzuzqKiaGnm/Xh/6L5tLJypGtfmM2kE3IixxVyNd5tURiLH/24Hi XN7f7GP61eB39zwsjvWYRnfODaJQtPY= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id AC5A91390D; Tue, 28 Mar 2023 08:46:04 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id X72GKEypImQKLwAAMHmgww (envelope-from ); Tue, 28 Mar 2023 08:46:04 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Cc: Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, Dan Carpenter Subject: [PATCH] xen/scsiback: don't call scsiback_free_translation_entry() under lock Date: Tue, 28 Mar 2023 10:46:02 +0200 Message-Id: <20230328084602.20729-1-jgross@suse.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" scsiback_free_translation_entry() shouldn't be called under spinlock, as it can sleep. This requires to split removing a translation entry from the v2p list from actually calling kref_put() for the entry. Reported-by: Dan Carpenter Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/ Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko --- drivers/xen/xen-scsiback.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c index 954188b0b858..294f29cdc7aa 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -1010,12 +1010,6 @@ static int scsiback_add_translation_entry(struct vsc= sibk_info *info, return err; } =20 -static void __scsiback_del_translation_entry(struct v2p_entry *entry) -{ - list_del(&entry->l); - kref_put(&entry->kref, scsiback_free_translation_entry); -} - /* Delete the translation entry specified */ @@ -1024,18 +1018,20 @@ static int scsiback_del_translation_entry(struct vs= csibk_info *info, { struct v2p_entry *entry; unsigned long flags; - int ret =3D 0; =20 spin_lock_irqsave(&info->v2p_lock, flags); /* Find out the translation entry specified */ entry =3D scsiback_chk_translation_entry(info, v); if (entry) - __scsiback_del_translation_entry(entry); - else - ret =3D -ENOENT; + list_del(&entry->l); =20 spin_unlock_irqrestore(&info->v2p_lock, flags); - return ret; + + if (!entry) + return -ENOENT; + + kref_put(&entry->kref, scsiback_free_translation_entry); + return 0; } =20 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *sta= te, @@ -1239,14 +1235,19 @@ static void scsiback_release_translation_entry(stru= ct vscsibk_info *info) { struct v2p_entry *entry, *tmp; struct list_head *head =3D &(info->v2p_entry_lists); + struct list_head tmp_list; unsigned long flags; =20 spin_lock_irqsave(&info->v2p_lock, flags); =20 - list_for_each_entry_safe(entry, tmp, head, l) - __scsiback_del_translation_entry(entry); + list_cut_before(&tmp_list, head, head); =20 spin_unlock_irqrestore(&info->v2p_lock, flags); + + list_for_each_entry_safe(entry, tmp, &tmp_list, l) { + list_del(&entry->l); + kref_put(&entry->kref, scsiback_free_translation_entry); + } } =20 static void scsiback_remove(struct xenbus_device *dev) --=20 2.35.3