From patchwork Tue Mar 28 08:46:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 13190675 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 645C5C76196 for ; Tue, 28 Mar 2023 08:46:25 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.515593.798617 (Exim 4.92) (envelope-from ) id 1ph4y0-0007vg-4p; Tue, 28 Mar 2023 08:46:08 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 515593.798617; Tue, 28 Mar 2023 08:46:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ph4y0-0007vZ-2G; Tue, 28 Mar 2023 08:46:08 +0000 Received: by outflank-mailman (input) for mailman id 515593; Tue, 28 Mar 2023 08:46:07 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ph4xz-0007dl-6m for xen-devel@lists.xenproject.org; Tue, 28 Mar 2023 08:46:07 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [2001:67c:2178:6::1d]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id f95cfe1f-cd44-11ed-b464-930f4c7d94ae; Tue, 28 Mar 2023 10:46:04 +0200 (CEST) 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) 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 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: f95cfe1f-cd44-11ed-b464-930f4c7d94ae 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= 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 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 vscsibk_info *info, return err; } -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 vscsibk_info *info, { struct v2p_entry *entry; unsigned long flags; - int ret = 0; spin_lock_irqsave(&info->v2p_lock, flags); /* Find out the translation entry specified */ entry = scsiback_chk_translation_entry(info, v); if (entry) - __scsiback_del_translation_entry(entry); - else - ret = -ENOENT; + list_del(&entry->l); spin_unlock_irqrestore(&info->v2p_lock, flags); - return ret; + + if (!entry) + return -ENOENT; + + kref_put(&entry->kref, scsiback_free_translation_entry); + return 0; } static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, @@ -1239,14 +1235,19 @@ static void scsiback_release_translation_entry(struct vscsibk_info *info) { struct v2p_entry *entry, *tmp; struct list_head *head = &(info->v2p_entry_lists); + struct list_head tmp_list; unsigned long flags; spin_lock_irqsave(&info->v2p_lock, flags); - list_for_each_entry_safe(entry, tmp, head, l) - __scsiback_del_translation_entry(entry); + list_cut_before(&tmp_list, head, head); 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); + } } static void scsiback_remove(struct xenbus_device *dev)