From patchwork Fri Mar 24 16:56:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paulo Alcantara X-Patchwork-Id: 13187003 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 06126C6FD1C for ; Fri, 24 Mar 2023 16:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230021AbjCXQ4o (ORCPT ); Fri, 24 Mar 2023 12:56:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231608AbjCXQ4n (ORCPT ); Fri, 24 Mar 2023 12:56:43 -0400 Received: from mx.manguebit.com (mx.manguebit.com [167.235.159.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8587CA9 for ; Fri, 24 Mar 2023 09:56:42 -0700 (PDT) From: Paulo Alcantara DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manguebit.com; s=dkim; t=1679677000; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=+swoB9cir7CdV+UF2zOItQXXE6oCK43tQ1ufYulnD1U=; b=ahFSwELGTFzOj6ipfi1fJuoRGw3oFU9nxoPBETOY8WsvEtBhzFUWqI7zVscKiGzh2YnPZr ESp4peJZy68Q9kDjsTpJvnsSMTkER5bA/2M5j0cV+XqEzGArHY5YblH0C3CbVMkLfPOVfY S79jUhXIGZdpdQsnkMVJhskgKWJ73ilWCmCANDeoAl956sZBO44pyl3d59F2aKijNSHAzy yv/TbL9owTvTlnSGI5U1dKyGeW1dtiHbSvPBQOAlzFGR2AvewwNJVTlsnBAio0de609O+7 tu2GNeui8C/y1Ec16XyQexn6w6Gf6erTeE4HGUl6BmFw1ajmP+UrHchV8nCC7A== ARC-Seal: i=1; s=dkim; d=manguebit.com; t=1679677000; a=rsa-sha256; cv=none; b=dvJkY5NkhruYXpRmEACRFWYjfLESE1m5LSBQUBKyHn2Nvduo79KUiX2WQUeMKvAEwnPFMX CpQwkXyIVZ4DOgEIc5eFAHZhasmw0s/+kxIx3nwVQ0O2cmw5iIlmRvP6PjYY6YclC3RIe0 smETR44p/E9NHqq9hexvD3J/lTF0YKWvpVeFDanVKS/6Zl4hwVVEQ9IRsIGXjMHpOOcEar EyhKekReAHlPYbH6dULRDyT+NlMruImUC9i1/Y641/MQQIoCPtUGVWRdI22PrOdGtX3L05 z7IO87yRqThYp4ExRUhL2OBH9YSlqvmtZWT//OjLs+u1xFtEW9sB3Q0yd7AKfw== ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pc@manguebit.com smtp.mailfrom=pc@manguebit.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=manguebit.com; s=dkim; t=1679677000; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=+swoB9cir7CdV+UF2zOItQXXE6oCK43tQ1ufYulnD1U=; b=A1qEW0RbI/G7f83ozeXc0RkNqNfCIgJixkJIEVLBVEAQubkeBqOsRRHzk2md72j3uyz3Jq hnJ3x4gPMseHyq77WvF6rq9ve9M2e4Hn6RT8FAyqBBKFqodYx+8pZJcFVlRCfLOAruktIu oiTJozJN5vkhw56s8yf9X3RF3cuCNiiASaREmmQit9jyfoajU0+O/ykw2q0GeNTZWWhw1W hQikAyl6pEOrNDzXtTXCt3OopENSOdaLDAH/s9eCuGkq4SwhpklYaPtJVm6uyh121rNbaw ZN22kR+X5Zpd9H2DN7mg02FQ/0gvsgHyfy9zT4X9Jh+PElXvJzqLb+iNet4idQ== To: smfrench@gmail.com Cc: linux-cifs@vger.kernel.org, Paulo Alcantara Subject: [PATCH] cifs: fix dentry lookups in directory handle cache Date: Fri, 24 Mar 2023 13:56:33 -0300 Message-Id: <20230324165633.22702-1-pc@manguebit.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Get rid of any prefix paths in @path before lookup_positive_unlocked() as it will call ->lookup() which already adds those prefix paths through build_path_from_dentry(). This has caused a performance regression when mounting shares with a prefix path where readdir(2) would end up retrying several times to open bad directory names that contained duplicate prefix paths. Fix this by skipping any prefix paths in @path before calling lookup_positive_unlocked(). Fixes: e4029e072673 ("cifs: find and use the dentry for cached non-root directories also") Signed-off-by: Paulo Alcantara (SUSE) --- fs/cifs/cached_dir.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cached_dir.c b/fs/cifs/cached_dir.c index 71fabb4c09a4..bfc964b36c72 100644 --- a/fs/cifs/cached_dir.c +++ b/fs/cifs/cached_dir.c @@ -99,6 +99,23 @@ path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path) return dentry; } +static const char *path_no_prefix(struct cifs_sb_info *cifs_sb, + const char *path) +{ + size_t len = 0; + + if (!*path) + return path; + + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) && + cifs_sb->prepath) { + len = strlen(cifs_sb->prepath) + 1; + if (unlikely(len > strlen(path))) + return ERR_PTR(-EINVAL); + } + return path + len; +} + /* * Open the and cache a directory handle. * If error then *cfid is not initialized. @@ -125,6 +142,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, struct dentry *dentry = NULL; struct cached_fid *cfid; struct cached_fids *cfids; + const char *npath; if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache || is_smb1_server(tcon->ses->server)) @@ -160,6 +178,20 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, return 0; } + /* + * Skip any prefix paths in @path as lookup_positive_unlocked() ends up + * calling ->lookup() which already adds those through + * build_path_from_dentry(). Also, do it earlier as we might reconnect + * below when trying to send compounded request and then potentially + * having a different prefix path (e.g. after DFS failover). + */ + npath = path_no_prefix(cifs_sb, path); + if (IS_ERR(npath)) { + rc = PTR_ERR(npath); + kfree(utf16_path); + return rc; + } + /* * We do not hold the lock for the open because in case * SMB2_open needs to reconnect. @@ -252,10 +284,10 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, (char *)&cfid->file_all_info)) cfid->file_all_info_is_valid = true; - if (!path[0]) + if (!npath[0]) dentry = dget(cifs_sb->root); else { - dentry = path_to_dentry(cifs_sb, path); + dentry = path_to_dentry(cifs_sb, npath); if (IS_ERR(dentry)) { rc = -ENOENT; goto oshr_free;