From nobody Sun Feb 8 15:28:37 2026 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 A225BEB64DC for ; Fri, 21 Jul 2023 10:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230441AbjGUKtr (ORCPT ); Fri, 21 Jul 2023 06:49:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230137AbjGUKtc (ORCPT ); Fri, 21 Jul 2023 06:49:32 -0400 Received: from out30-124.freemail.mail.aliyun.com (out30-124.freemail.mail.aliyun.com [115.124.30.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 689C5171A for ; Fri, 21 Jul 2023 03:49:30 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VnuOFUN_1689936566; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VnuOFUN_1689936566) by smtp.aliyun-inc.com; Fri, 21 Jul 2023 18:49:26 +0800 From: Jingbo Xu To: hsiangkao@linux.alibaba.com, chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, alexl@redhat.com Subject: [PATCH v5 2/2] erofs: boost negative xattr lookup with bloom filter Date: Fri, 21 Jul 2023 18:49:23 +0800 Message-Id: <20230721104923.20236-3-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20230721104923.20236-1-jefflexu@linux.alibaba.com> References: <20230721104923.20236-1-jefflexu@linux.alibaba.com> 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" Optimise the negative xattr lookup with bloom filter. The bit value for the bloom filter map has a reverse semantics for compatibility. That is, the bit value of 0 indicates existence, while the bit value of 1 indicates the absence of corresponding xattr. The initial version is _only_ enabled when xattr_filter_reserved is zero. The filter map internals may change in the future, in which case the reserved flag will be set non-zero and we don't need bothering the compatible bits again at that time. For now disable the optimization if this reserved flag is non-zero. Signed-off-by: Jingbo Xu --- fs/erofs/Kconfig | 1 + fs/erofs/internal.h | 3 +++ fs/erofs/super.c | 1 + fs/erofs/xattr.c | 14 ++++++++++++++ 4 files changed, 19 insertions(+) diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index f259d92c9720..f49669def828 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -38,6 +38,7 @@ config EROFS_FS_DEBUG config EROFS_FS_XATTR bool "EROFS extended attributes" depends on EROFS_FS + select XXHASH default y help Extended attributes are name:value pairs associated with inodes by diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 36e32fa542f0..3c1f89d8421b 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -151,6 +151,7 @@ struct erofs_sb_info { u32 xattr_prefix_start; u8 xattr_prefix_count; struct erofs_xattr_prefix_item *xattr_prefixes; + unsigned int xattr_filter_reserved; #endif u16 device_id_mask; /* valid bits of device id to be used */ =20 @@ -251,6 +252,7 @@ EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGM= ENTS) EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE) EROFS_FEATURE_FUNCS(xattr_prefixes, incompat, INCOMPAT_XATTR_PREFIXES) EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) +EROFS_FEATURE_FUNCS(xattr_filter, compat, COMPAT_XATTR_FILTER) =20 /* atomic flag definitions */ #define EROFS_I_EA_INITED_BIT 0 @@ -270,6 +272,7 @@ struct erofs_inode { unsigned char inode_isize; unsigned int xattr_isize; =20 + unsigned int xattr_name_filter; unsigned int xattr_shared_count; unsigned int *xattr_shared_xattrs; =20 diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 9d6a3c6158bd..72122323300e 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -388,6 +388,7 @@ static int erofs_read_superblock(struct super_block *sb) sbi->xattr_blkaddr =3D le32_to_cpu(dsb->xattr_blkaddr); sbi->xattr_prefix_start =3D le32_to_cpu(dsb->xattr_prefix_start); sbi->xattr_prefix_count =3D dsb->xattr_prefix_count; + sbi->xattr_filter_reserved =3D dsb->xattr_filter_reserved; #endif sbi->islotbits =3D ilog2(sizeof(struct erofs_inode_compact)); sbi->root_nid =3D le16_to_cpu(dsb->root_nid); diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 40178b6e0688..e9b9ed6b28d2 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -5,6 +5,7 @@ * Copyright (C) 2021-2022, Alibaba Cloud */ #include +#include #include "xattr.h" =20 struct erofs_xattr_iter { @@ -87,6 +88,7 @@ static int erofs_init_inode_xattrs(struct inode *inode) } =20 ih =3D it.kaddr + erofs_blkoff(sb, it.pos); + vi->xattr_name_filter =3D le32_to_cpu(ih->h_name_filter); vi->xattr_shared_count =3D ih->h_shared_count; vi->xattr_shared_xattrs =3D kmalloc_array(vi->xattr_shared_count, sizeof(uint), GFP_KERNEL); @@ -392,7 +394,10 @@ int erofs_getxattr(struct inode *inode, int index, con= st char *name, void *buffer, size_t buffer_size) { int ret; + uint32_t hashbit; struct erofs_xattr_iter it; + struct erofs_inode *vi =3D EROFS_I(inode); + struct erofs_sb_info *sbi =3D EROFS_SB(inode->i_sb); =20 if (!name) return -EINVAL; @@ -401,6 +406,15 @@ int erofs_getxattr(struct inode *inode, int index, con= st char *name, if (ret) return ret; =20 + /* reserved flag is non-zero if there's any change of on-disk format */ + if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved) { + hashbit =3D xxh32(name, strlen(name), + EROFS_XATTR_FILTER_SEED + index); + hashbit &=3D EROFS_XATTR_FILTER_BITS - 1; + if (vi->xattr_name_filter & (1U << hashbit)) + return -ENOATTR; + } + it.index =3D index; it.name =3D (struct qstr)QSTR_INIT(name, strlen(name)); if (it.name.len > EROFS_NAME_LEN) --=20 2.19.1.6.gb485710b