From nobody Tue Feb 10 01:15:03 2026 Received: from canpmsgout11.his.huawei.com (canpmsgout11.his.huawei.com [113.46.200.226]) (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 0822D32E12E for ; Tue, 21 Oct 2025 10:59:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.226 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761044386; cv=none; b=RDx2cu1/fy3fT+3iidl0leH21259rITSHsW3NJiC2+qbHBXm5kZOB9XHOYlnBmy0EZfj5V0JZIgm1L36j1om0wPnjm9UMNkd25bORSoh4oL5Uuu8uThd+mAdE3ubENlUiEQzMKVnbfULqE2+S6VCQg1kVGig/OLSPBtGAn64rmU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761044386; c=relaxed/simple; bh=JhNd83WD2w/WLEeLAvyx8sCelylgN07rekchxNwHQBY=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Z7eemQ/HQXSWuUfAqq65klqwjuSs+lJPA3XFQttbkiRX2viF8x7fFI+9kbHBB9TX6tPpv08f/zPAyVJp2XZ8Vrct1A22bDOkcu51EkRGM/hu629Vn+H1cboraYHlqsH6V0INNoOCYB+8lILhSj4hLQyV/uGv7+TsvUTsFPIf4cQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=1dRJFm92; arc=none smtp.client-ip=113.46.200.226 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="1dRJFm92" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=LY07TegupRGvSH/9+tapmPTo/3N1TCD/ljyoNiLW+uE=; b=1dRJFm92O/Ob7s4AZR8cRATGWCbuqsGQ5t0VTKsGnL8F6JKz80VYYpQExCGGoORilrLZCwWpS fvQET1psEIgqMO0tKVnui7dMEHL7YjMpyKaA6CGcfn8w3HYmf+ij1rJtgbosF/3wTJnwdobe46L xjUdRqksDRBtpL4AWl2PEPc= Received: from mail.maildlp.com (unknown [172.19.88.163]) by canpmsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4crTnV6LdmzKm5G; Tue, 21 Oct 2025 18:59:10 +0800 (CST) Received: from kwepemr500015.china.huawei.com (unknown [7.202.195.162]) by mail.maildlp.com (Postfix) with ESMTPS id BA3A018001B; Tue, 21 Oct 2025 18:59:34 +0800 (CST) Received: from huawei.com (10.67.174.162) by kwepemr500015.china.huawei.com (7.202.195.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 21 Oct 2025 18:59:34 +0800 From: Hongbo Li To: , , , CC: , , Subject: [PATCH RFC v7 5/7] erofs: support unencoded inodes for page cache share Date: Tue, 21 Oct 2025 10:48:13 +0000 Message-ID: <20251021104815.70662-6-lihongbo22@huawei.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20251021104815.70662-1-lihongbo22@huawei.com> References: <20251021104815.70662-1-lihongbo22@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To kwepemr500015.china.huawei.com (7.202.195.162) Content-Type: text/plain; charset="utf-8" From: Hongzhen Luo This patch adds inode page cache sharing functionality for unencoded files. I conducted experiments in the container environment. Below is the memory usage for reading all files in two different minor versions of container images: +-------------------+------------------+-------------+---------------+ | Image | Page Cache Share | Memory (MB) | Memory | | | | | Reduction (%) | +-------------------+------------------+-------------+---------------+ | | No | 241 | - | | redis +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 163 | 33% | +-------------------+------------------+-------------+---------------+ | | No | 872 | - | | postgres +------------------+-------------+---------------+ | 16.1 & 16.2 | Yes | 630 | 28% | +-------------------+------------------+-------------+---------------+ | | No | 2771 | - | | tensorflow +------------------+-------------+---------------+ | 2.11.0 & 2.11.1 | Yes | 2340 | 16% | +-------------------+------------------+-------------+---------------+ | | No | 926 | - | | mysql +------------------+-------------+---------------+ | 8.0.11 & 8.0.12 | Yes | 735 | 21% | +-------------------+------------------+-------------+---------------+ | | No | 390 | - | | nginx +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 219 | 44% | +-------------------+------------------+-------------+---------------+ | tomcat | No | 924 | - | | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ | | Yes | 474 | 49% | +-------------------+------------------+-------------+---------------+ Additionally, the table below shows the runtime memory usage of the container: +-------------------+------------------+-------------+---------------+ | Image | Page Cache Share | Memory (MB) | Memory | | | | | Reduction (%) | +-------------------+------------------+-------------+---------------+ | | No | 35 | - | | redis +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 28 | 20% | +-------------------+------------------+-------------+---------------+ | | No | 149 | - | | postgres +------------------+-------------+---------------+ | 16.1 & 16.2 | Yes | 95 | 37% | +-------------------+------------------+-------------+---------------+ | | No | 1028 | - | | tensorflow +------------------+-------------+---------------+ | 2.11.0 & 2.11.1 | Yes | 930 | 10% | +-------------------+------------------+-------------+---------------+ | | No | 155 | - | | mysql +------------------+-------------+---------------+ | 8.0.11 & 8.0.12 | Yes | 132 | 15% | +-------------------+------------------+-------------+---------------+ | | No | 25 | - | | nginx +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 20 | 20% | +-------------------+------------------+-------------+---------------+ | tomcat | No | 186 | - | | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ | | Yes | 98 | 48% | +-------------------+------------------+-------------+---------------+ Signed-off-by: Hongzhen Luo [hongbo: forward port, minor fixes and cleanup] Signed-off-by: Hongbo Li --- fs/erofs/data.c | 81 ++++++++++++++++++++++++++++++++++++++----- fs/erofs/inode.c | 5 +++ fs/erofs/internal.h | 4 +++ fs/erofs/ishare.c | 83 +++++++++++++++++++++++++++++++++++++++++++++ fs/erofs/ishare.h | 18 ++++++++++ fs/erofs/super.c | 7 ++++ 6 files changed, 190 insertions(+), 8 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 8ca29962a3dd..438d43c959aa 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -5,6 +5,7 @@ * Copyright (C) 2021, Alibaba Cloud */ #include "internal.h" +#include "ishare.h" #include #include =20 @@ -266,25 +267,55 @@ void erofs_onlinefolio_end(struct folio *folio, int e= rr, bool dirty) folio_end_read(folio, !(v & BIT(EROFS_ONLINEFOLIO_EIO))); } =20 +struct erofs_iomap { + void *base; + struct inode *realinode; +}; + static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t le= ngth, unsigned int flags, struct iomap *iomap, struct iomap *srcmap) { int ret; - struct super_block *sb =3D inode->i_sb; + struct super_block *sb; struct erofs_map_blocks map; struct erofs_map_dev mdev; + struct inode *realinode =3D inode; + struct erofs_iomap *erofs_iomap; + bool is_ishare =3D erofs_is_ishare_inode(inode); + + if (is_ishare) { + if (!iomap->private) { + erofs_iomap =3D kzalloc(sizeof(*erofs_iomap), + GFP_KERNEL); + if (!erofs_iomap) + return -ENOMEM; + erofs_iomap->realinode =3D erofs_ishare_iget(inode); + if (!erofs_iomap->realinode) { + kfree(erofs_iomap); + return -EINVAL; + } + iomap->private =3D erofs_iomap; + } + erofs_iomap =3D iomap->private; + realinode =3D erofs_iomap->realinode; + } =20 + sb =3D realinode->i_sb; map.m_la =3D offset; map.m_llen =3D length; - ret =3D erofs_map_blocks(inode, &map); + ret =3D erofs_map_blocks(realinode, &map); if (ret < 0) return ret; =20 iomap->offset =3D map.m_la; iomap->length =3D map.m_llen; iomap->flags =3D 0; - iomap->private =3D NULL; iomap->addr =3D IOMAP_NULL_ADDR; + + if (is_ishare) + erofs_iomap->base =3D NULL; + else + iomap->private =3D NULL; if (!(map.m_flags & EROFS_MAP_MAPPED)) { iomap->type =3D IOMAP_HOLE; return 0; @@ -318,7 +349,10 @@ static int erofs_iomap_begin(struct inode *inode, loff= _t offset, loff_t length, if (IS_ERR(ptr)) return PTR_ERR(ptr); iomap->inline_data =3D ptr; - iomap->private =3D buf.base; + if (is_ishare) + erofs_iomap->base =3D buf.base; + else + iomap->private =3D buf.base; } else { iomap->type =3D IOMAP_MAPPED; } @@ -328,7 +362,17 @@ static int erofs_iomap_begin(struct inode *inode, loff= _t offset, loff_t length, static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length, ssize_t written, unsigned int flags, struct iomap *iomap) { - void *ptr =3D iomap->private; + struct erofs_iomap *erofs_iomap; + bool is_ishare; + void *ptr; + + is_ishare =3D erofs_is_ishare_inode(inode); + if (is_ishare) { + erofs_iomap =3D iomap->private; + ptr =3D erofs_iomap->base; + } else { + ptr =3D iomap->private; + } =20 if (ptr) { struct erofs_buf buf =3D { @@ -341,6 +385,12 @@ static int erofs_iomap_end(struct inode *inode, loff_t= pos, loff_t length, } else { DBG_BUGON(iomap->type =3D=3D IOMAP_INLINE); } + + if (is_ishare) { + erofs_ishare_iput(erofs_iomap->realinode); + kfree(erofs_iomap); + iomap->private =3D NULL; + } return written; } =20 @@ -369,17 +419,32 @@ int erofs_fiemap(struct inode *inode, struct fiemap_e= xtent_info *fieinfo, */ static int erofs_read_folio(struct file *file, struct folio *folio) { + struct erofs_read_ctx rdctx =3D { + .file =3D file, + .inode =3D folio_inode(folio), + }; + int ret; + + erofs_read_begin(&rdctx); + ret =3D iomap_read_folio(folio, &erofs_iomap_ops); + erofs_read_end(&rdctx); trace_erofs_read_folio(folio, true); =20 - return iomap_read_folio(folio, &erofs_iomap_ops); + return ret; } =20 static void erofs_readahead(struct readahead_control *rac) { + struct erofs_read_ctx rdctx =3D { + .file =3D rac->file, + .inode =3D rac->mapping->host, + }; + + erofs_read_begin(&rdctx); + iomap_readahead(rac, &erofs_iomap_ops); + erofs_read_end(&rdctx); trace_erofs_readahead(rac->mapping->host, readahead_index(rac), readahead_count(rac), true); - - return iomap_readahead(rac, &erofs_iomap_ops); } =20 static sector_t erofs_bmap(struct address_space *mapping, sector_t block) diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index cb780c095d28..fe45e6c18f8e 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -5,6 +5,7 @@ * Copyright (C) 2021, Alibaba Cloud */ #include "xattr.h" +#include "ishare.h" #include #include =20 @@ -215,6 +216,10 @@ static int erofs_fill_inode(struct inode *inode) case S_IFREG: inode->i_op =3D &erofs_generic_iops; inode->i_fop =3D &erofs_file_fops; +#ifdef CONFIG_EROFS_FS_INODE_SHARE + if (erofs_ishare_fill_inode(inode)) + inode->i_fop =3D &erofs_ishare_fops; +#endif break; case S_IFDIR: inode->i_op =3D &erofs_dir_iops; diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 158bda6ba784..9ce6e5753978 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -322,11 +322,15 @@ struct erofs_inode { spinlock_t lock; /* all backing inodes */ struct list_head backing_head; + /* processing list */ + struct list_head processing_head; }; =20 struct { struct inode *ishare; struct list_head backing_link; + struct list_head processing_link; + atomic_t processing_count; }; }; #endif diff --git a/fs/erofs/ishare.c b/fs/erofs/ishare.c index 910b732bf8e7..73432b13bf75 100644 --- a/fs/erofs/ishare.c +++ b/fs/erofs/ishare.c @@ -72,6 +72,7 @@ static int erofs_ishare_iget5_set(struct inode *inode, vo= id *data) =20 vi->fingerprint =3D data; INIT_LIST_HEAD(&vi->backing_head); + INIT_LIST_HEAD(&vi->processing_head); spin_lock_init(&vi->lock); return 0; } @@ -124,7 +125,9 @@ bool erofs_ishare_fill_inode(struct inode *inode) } =20 INIT_LIST_HEAD(&vi->backing_link); + INIT_LIST_HEAD(&vi->processing_link); vi->ishare =3D idedup; + spin_lock(&EROFS_I(idedup)->lock); list_add(&vi->backing_link, &EROFS_I(idedup)->backing_head); spin_unlock(&EROFS_I(idedup)->lock); @@ -234,3 +237,83 @@ const struct file_operations erofs_ishare_fops =3D { .get_unmapped_area =3D thp_get_unmapped_area, .splice_read =3D filemap_splice_read, }; + +void erofs_read_begin(struct erofs_read_ctx *rdctx) +{ + struct erofs_inode *vi, *vi_dedup; + + if (!rdctx->file || !erofs_is_ishare_inode(rdctx->inode)) + return; + + vi =3D rdctx->file->private_data; + vi_dedup =3D EROFS_I(file_inode(rdctx->file)); + + spin_lock(&vi_dedup->lock); + if (!list_empty(&vi->processing_link)) { + atomic_inc(&vi->processing_count); + } else { + list_add(&vi->processing_link, + &vi_dedup->processing_head); + atomic_set(&vi->processing_count, 1); + } + spin_unlock(&vi_dedup->lock); +} + +void erofs_read_end(struct erofs_read_ctx *rdctx) +{ + struct erofs_inode *vi, *vi_dedup; + + if (!rdctx->file || !erofs_is_ishare_inode(rdctx->inode)) + return; + + vi =3D rdctx->file->private_data; + vi_dedup =3D EROFS_I(file_inode(rdctx->file)); + + spin_lock(&vi_dedup->lock); + if (atomic_dec_and_test(&vi->processing_count)) + list_del_init(&vi->processing_link); + spin_unlock(&vi_dedup->lock); +} + +/* + * erofs_ishare_iget - find the backing inode. + */ +struct inode *erofs_ishare_iget(struct inode *inode) +{ + struct erofs_inode *vi, *vi_dedup; + struct inode *realinode; + + if (!erofs_is_ishare_inode(inode)) + return igrab(inode); + + vi_dedup =3D EROFS_I(inode); + spin_lock(&vi_dedup->lock); + /* try processing inodes first */ + if (!list_empty(&vi_dedup->processing_head)) { + list_for_each_entry(vi, &vi_dedup->processing_head, + processing_link) { + realinode =3D igrab(&vi->vfs_inode); + if (realinode) { + spin_unlock(&vi_dedup->lock); + return realinode; + } + } + } + + /* fall back to all backing inodes */ + DBG_BUGON(list_empty(&vi_dedup->backing_head)); + list_for_each_entry(vi, &vi_dedup->backing_head, backing_link) { + realinode =3D igrab(&vi->vfs_inode); + if (realinode) + break; + } + spin_unlock(&vi_dedup->lock); + + DBG_BUGON(!realinode); + return realinode; +} + +void erofs_ishare_iput(struct inode *realinode) +{ + iput(realinode); +} diff --git a/fs/erofs/ishare.h b/fs/erofs/ishare.h index 54f2251c8179..b85fa240507b 100644 --- a/fs/erofs/ishare.h +++ b/fs/erofs/ishare.h @@ -9,6 +9,11 @@ #include #include "internal.h" =20 +struct erofs_read_ctx { + struct file *file; /* may be NULL */ + struct inode *inode; +}; + #ifdef CONFIG_EROFS_FS_INODE_SHARE =20 int erofs_ishare_init(struct super_block *sb); @@ -16,6 +21,13 @@ void erofs_ishare_exit(struct super_block *sb); bool erofs_ishare_fill_inode(struct inode *inode); void erofs_ishare_free_inode(struct inode *inode); =20 +/* read/readahead */ +void erofs_read_begin(struct erofs_read_ctx *rdctx); +void erofs_read_end(struct erofs_read_ctx *rdctx); + +struct inode *erofs_ishare_iget(struct inode *inode); +void erofs_ishare_iput(struct inode *realinode); + #else =20 static inline int erofs_ishare_init(struct super_block *sb) { return 0; } @@ -23,6 +35,12 @@ static inline void erofs_ishare_exit(struct super_block = *sb) {} static inline bool erofs_ishare_fill_inode(struct inode *inode) { return f= alse; } static inline void erofs_ishare_free_inode(struct inode *inode) {} =20 +static inline void erofs_read_begin(struct erofs_read_ctx *rdctx) {} +static inline void erofs_read_end(struct erofs_read_ctx *rdctx) {} + +static inline struct inode *erofs_ishare_iget(struct inode *inode) { retur= n inode; } +static inline void erofs_ishare_iput(struct inode *realinode) {} + #endif // CONFIG_EROFS_FS_INODE_SHARE =20 #endif diff --git a/fs/erofs/super.c b/fs/erofs/super.c index f067633c0072..cba3da383558 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -97,6 +97,7 @@ static void erofs_free_inode(struct inode *inode) erofs_free_dedup_inode(vi); return; } + erofs_ishare_free_inode(inode); if (inode->i_op =3D=3D &erofs_fast_symlink_iops) kfree(inode->i_link); kfree(vi->xattr_shared_xattrs); @@ -762,6 +763,10 @@ static int erofs_fc_fill_super(struct super_block *sb,= struct fs_context *fc) if (err) return err; =20 + err =3D erofs_ishare_init(sb); + if (err) + return err; + sbi->dir_ra_bytes =3D EROFS_DIR_RA_BYTES; erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid); return 0; @@ -911,6 +916,7 @@ static void erofs_kill_sb(struct super_block *sb) kill_anon_super(sb); else kill_block_super(sb); + erofs_drop_internal_inodes(sbi); fs_put_dax(sbi->dif0.dax_dev, NULL); erofs_fscache_unregister_fs(sb); @@ -922,6 +928,7 @@ static void erofs_put_super(struct super_block *sb) { struct erofs_sb_info *const sbi =3D EROFS_SB(sb); =20 + erofs_ishare_exit(sb); erofs_unregister_sysfs(sb); erofs_shrinker_unregister(sb); erofs_xattr_prefixes_cleanup(sb); --=20 2.22.0