From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55FBB79F0; Mon, 8 Apr 2024 13:48:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712584139; cv=none; b=pTn0j81GUZ0PHLKi4xBxMpuGgw2yOFscbucOy4eHmeevU2auTl4KnGhMcUbSdabmKGlIOESLwP6WtMakXdAOwxmdwgA1ahNZ1I2/ksImnFebQzPGrXoczOd3DiWybwO/lsYx5c5GFPXX3GKxx323GnEHabRJUAjducBQ2Tx+vvA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712584139; c=relaxed/simple; bh=qYZkIg7CwvsOs5ML1cn9OGrnsM8MIkCqOZLEVQpGigU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bdrrMRDwZsqPPQaHtBC7Il/5uBAZSDmjxNIn/ZKFwyTwpIp7nOF+95FSorX4rS/siZZBJCFhD8N5JFl0Pv084vfMYlPcbymI1CszDyF0CfW8vEEKMvR5bUp60lv5hcfNjiR6KHP+eYesmoCEpgfn7ZonVklD4gwnzCdKE+aVl5Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WL/CNUJm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WL/CNUJm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 793C7C433C7; Mon, 8 Apr 2024 13:48:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712584138; bh=qYZkIg7CwvsOs5ML1cn9OGrnsM8MIkCqOZLEVQpGigU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WL/CNUJmVn83mjb4QUk2c+G3XoBBA8kAm9GWjh09VLOiWGzLqUpc/E6J8Msxtq+lc CnrZC8XyZ5Q1pwRbYYjeXSEnxIvvCgI9SOgyirW/cjmgQCysqI3ngzLnQEAdA5HZMI jWhbciAFzTXJXrWZeYwOFI3Kywi0nf6qUoMJYjVs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Paulo Alcantara (Red Hat)" , Steve French Subject: [PATCH 6.8 245/273] smb: client: refresh referral without acquiring refpath_lock Date: Mon, 8 Apr 2024 14:58:40 +0200 Message-ID: <20240408125317.050430122@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125309.280181634@linuxfoundation.org> References: <20240408125309.280181634@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara commit 0a05ad21d77a188d06481c36d6016805a881bcc0 upstream. Avoid refreshing DFS referral with refpath_lock acquired as the I/O could block for a while due to a potentially disconnected or slow DFS root server and then making other threads - that use same @server and don't require a DFS root server - unable to make any progress. Cc: stable@vger.kernel.org # 6.4+ Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/dfs_cache.c | 44 ++++++++++++++++++++++++-------------------- 1 file changed, 24 insertions(+), 20 deletions(-) --- a/fs/smb/client/dfs_cache.c +++ b/fs/smb/client/dfs_cache.c @@ -1172,8 +1172,8 @@ static bool is_ses_good(struct cifs_ses return ret; } -/* Refresh dfs referral of tcon and mark it for reconnect if needed */ -static int __refresh_tcon(const char *path, struct cifs_ses *ses, bool force_refresh) +/* Refresh dfs referral of @ses and mark it for reconnect if needed */ +static void __refresh_ses_referral(struct cifs_ses *ses, bool force_refresh) { struct TCP_Server_Info *server = ses->server; DFS_CACHE_TGT_LIST(old_tl); @@ -1181,10 +1181,21 @@ static int __refresh_tcon(const char *pa bool needs_refresh = false; struct cache_entry *ce; unsigned int xid; + char *path = NULL; int rc = 0; xid = get_xid(); + mutex_lock(&server->refpath_lock); + if (server->leaf_fullpath) { + path = kstrdup(server->leaf_fullpath + 1, GFP_ATOMIC); + if (!path) + rc = -ENOMEM; + } + mutex_unlock(&server->refpath_lock); + if (!path) + goto out; + down_read(&htable_rw_lock); ce = lookup_cache_entry(path); needs_refresh = force_refresh || IS_ERR(ce) || cache_entry_expired(ce); @@ -1218,19 +1229,17 @@ out: free_xid(xid); dfs_cache_free_tgts(&old_tl); dfs_cache_free_tgts(&new_tl); - return rc; + kfree(path); } -static int refresh_tcon(struct cifs_tcon *tcon, bool force_refresh) +static inline void refresh_ses_referral(struct cifs_ses *ses) { - struct TCP_Server_Info *server = tcon->ses->server; - struct cifs_ses *ses = tcon->ses; + __refresh_ses_referral(ses, false); +} - mutex_lock(&server->refpath_lock); - if (server->leaf_fullpath) - __refresh_tcon(server->leaf_fullpath + 1, ses, force_refresh); - mutex_unlock(&server->refpath_lock); - return 0; +static inline void force_refresh_ses_referral(struct cifs_ses *ses) +{ + __refresh_ses_referral(ses, true); } /** @@ -1271,25 +1280,20 @@ int dfs_cache_remount_fs(struct cifs_sb_ */ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; - return refresh_tcon(tcon, true); + force_refresh_ses_referral(tcon->ses); + return 0; } /* Refresh all DFS referrals related to DFS tcon */ void dfs_cache_refresh(struct work_struct *work) { - struct TCP_Server_Info *server; struct cifs_tcon *tcon; struct cifs_ses *ses; tcon = container_of(work, struct cifs_tcon, dfs_cache_work.work); - for (ses = tcon->ses; ses; ses = ses->dfs_root_ses) { - server = ses->server; - mutex_lock(&server->refpath_lock); - if (server->leaf_fullpath) - __refresh_tcon(server->leaf_fullpath + 1, ses, false); - mutex_unlock(&server->refpath_lock); - } + for (ses = tcon->ses; ses; ses = ses->dfs_root_ses) + refresh_ses_referral(ses); queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work, atomic_read(&dfs_cache_ttl) * HZ);