From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 46F693B7A8; Mon, 17 Nov 2025 02:55:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763348111; cv=none; b=cR82A1tI+ByW+s+1Tsxdxo+ca31JZHqJXY4m4ojhUz3/CMH7kCgAAO+Iq7FC0mSmOmi5YMLHYmzybNqi1j6+jOkKr65YJlqIod/G/jsGKv2ysD+DsCNfXEAHSw1xpe7KRikrtTBG08yMGnYOxxdGriGV7/BEa+bGderxcACyDR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763348111; c=relaxed/simple; bh=cYkO8+vABYHsKGF5qzcNXu8/YPUyUWSWUKNOgrolpzI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XNN1Bg0cwezFtpuVUlNuWhvYuylj3HIuc/VnjaqEwv4G1etzc5g8styemYjbprRXFihG8zU/Ji/1v9RkKVANVpveqi+p5I+y8fnsitx+pE2FBUXgpt4pV5Ny6xtIpwg/fFyOgtS/H4D1Og3a/BS0SlSEIWcicsatcLkwa8je1v8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=yPMKdoRT; arc=none smtp.client-ip=115.124.30.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="yPMKdoRT" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1763348099; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=bM0pzBOedq7loaoI6fMCzbNwCpdPGiGv5NHJEFsZE28=; b=yPMKdoRTU6NbY+uO46to1oeIrg4bFYiS0765bPEd64aEbACW5LLbk0hfRs5D2dP9zxBJF436mxTkJPoz34wcblYop4u8ic6ZonGURfwMybKL6cHBiYL7Wd6qgFV4nxodaPby2edFjVSFgvEWzzIlfKRMMOcBh+t9BmDF8uBCsMs= Received: from 30.221.131.30(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0WsTm8Wr_1763348098 cluster:ay36) by smtp.aliyun-inc.com; Mon, 17 Nov 2025 10:54:58 +0800 Message-ID: Date: Mon, 17 Nov 2025 10:54:57 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 4/9] erofs: support user-defined fingerprint name To: Hongbo Li , chao@kernel.org, brauner@kernel.org, djwong@kernel.org, amir73il@gmail.com, joannelkoong@gmail.com Cc: linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20251114095516.207555-1-lihongbo22@huawei.com> <20251114095516.207555-5-lihongbo22@huawei.com> From: Gao Xiang In-Reply-To: <20251114095516.207555-5-lihongbo22@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/11/14 17:55, Hongbo Li wrote: > From: Hongzhen Luo > > When creating the EROFS image, users can specify the fingerprint name. > This is to prepare for the upcoming inode page cache share. > > Signed-off-by: Hongzhen Luo > Signed-off-by: Hongbo Li > --- > fs/erofs/Kconfig | 9 +++++++++ > fs/erofs/erofs_fs.h | 6 ++++-- > fs/erofs/internal.h | 6 ++++++ > fs/erofs/super.c | 5 ++++- > fs/erofs/xattr.c | 26 ++++++++++++++++++++++++++ > fs/erofs/xattr.h | 6 ++++++ > 6 files changed, 55 insertions(+), 3 deletions(-) > > diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig > index d81f3318417d..1b5c0cd99203 100644 > --- a/fs/erofs/Kconfig > +++ b/fs/erofs/Kconfig > @@ -194,3 +194,12 @@ config EROFS_FS_PCPU_KTHREAD_HIPRI > at higher priority. > > If unsure, say N. > + > +config EROFS_FS_INODE_SHARE > + bool "EROFS inode page cache share support (experimental)" > + depends on EROFS_FS && EROFS_FS_XATTR && !EROFS_FS_ONDEMAND > + help > + This permits EROFS to share page cache for files with same > + fingerprints. I tend to use "EROFS_FS_PAGE_CACHE_SHARE" since it's closer to user impact definition (inode sharing is ambiguious), but we could leave "ishare.c" since it's closer to the implementation details. And how about: config EROFS_FS_PAGE_CACHE_SHARE bool "EROFS page cache share support (experimental)" depends on EROFS_FS && EROFS_FS_XATTR && !EROFS_FS_ONDEMAND help This enables page cache sharing among inodes with identical content fingerprints on the same device. If unsure, say N. > + > + If unsure, say N. > \ No newline at end of file "\ No newline at end of file" should be fixed. > diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h > index 3d5738f80072..104518cd161d 100644 > --- a/fs/erofs/erofs_fs.h > +++ b/fs/erofs/erofs_fs.h > @@ -35,8 +35,9 @@ > #define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES 0x00000040 > #define EROFS_FEATURE_INCOMPAT_48BIT 0x00000080 > #define EROFS_FEATURE_INCOMPAT_METABOX 0x00000100 > +#define EROFS_FEATURE_INCOMPAT_ISHARE_KEY 0x00000200 I do think it should be a compatible feature since images can be mounted in the old kernels without any issue, and it should be renamed as EROFS_FEATURE_COMPAT_ISHARE_XATTRS > #define EROFS_ALL_FEATURE_INCOMPAT \ > - ((EROFS_FEATURE_INCOMPAT_METABOX << 1) - 1) > + ((EROFS_FEATURE_INCOMPAT_ISHARE_KEY << 1) - 1) > > #define EROFS_SB_EXTSLOT_SIZE 16 > > @@ -83,7 +84,8 @@ struct erofs_super_block { > __le32 xattr_prefix_start; /* start of long xattr prefixes */ > __le64 packed_nid; /* nid of the special packed inode */ > __u8 xattr_filter_reserved; /* reserved for xattr name filter */ > - __u8 reserved[3]; > + __u8 ishare_key_start; /* start of ishare key */ ishare_xattr_prefix_id; ? > + __u8 reserved[2]; > __le32 build_time; /* seconds added to epoch for mkfs time */ > __le64 rootnid_8b; /* (48BIT on) nid of root directory */ > __le64 reserved2; > diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h > index e80b35db18e4..3ebbb7c5d085 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -167,6 +167,11 @@ struct erofs_sb_info { > struct erofs_domain *domain; > char *fsid; > char *domain_id; > + > + /* inode page cache share support */ > + u8 ishare_key_start; u8 ishare_xattr_pfx; > + u8 ishare_key_idx; why need this, considering we could just use sbi->xattr_prefixes[sbi->ishare_xattr_pfx] to get this. > + char *ishare_key; > }; > > #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) > @@ -236,6 +241,7 @@ EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE) > EROFS_FEATURE_FUNCS(xattr_prefixes, incompat, INCOMPAT_XATTR_PREFIXES) > EROFS_FEATURE_FUNCS(48bit, incompat, INCOMPAT_48BIT) > EROFS_FEATURE_FUNCS(metabox, incompat, INCOMPAT_METABOX) > +EROFS_FEATURE_FUNCS(ishare_key, incompat, INCOMPAT_ISHARE_KEY) > EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) > EROFS_FEATURE_FUNCS(xattr_filter, compat, COMPAT_XATTR_FILTER) > EROFS_FEATURE_FUNCS(shared_ea_in_metabox, compat, COMPAT_SHARED_EA_IN_METABOX) > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index 0d88c04684b9..3561473cb789 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -339,7 +339,7 @@ static int erofs_read_superblock(struct super_block *sb) > return -EFSCORRUPTED; /* self-loop detection */ > } > sbi->inos = le64_to_cpu(dsb->inos); > - > + sbi->ishare_key_start = dsb->ishare_key_start; > sbi->epoch = (s64)le64_to_cpu(dsb->epoch); > sbi->fixed_nsec = le32_to_cpu(dsb->fixed_nsec); > super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid)); > @@ -738,6 +738,9 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) > if (err) > return err; > > + err = erofs_xattr_set_ishare_key(sb); I don't think it's necessary to duplicate the copy, just use "sbi->xattr_prefixes[sbi->ishare_xattr_pfx]" directly. Thanks, Gao Xiang > + if (err) > + return err; > erofs_set_sysfs_name(sb); > err = erofs_register_sysfs(sb); > if (err) > diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c > index 396536d9a862..3c99091f39a5 100644 > --- a/fs/erofs/xattr.c > +++ b/fs/erofs/xattr.c > @@ -564,3 +564,29 @@ struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu) > return acl; > } > #endif > + > +#ifdef CONFIG_EROFS_FS_INODE_SHARE > +int erofs_xattr_set_ishare_key(struct super_block *sb) > +{ > + struct erofs_sb_info *sbi = EROFS_SB(sb); > + struct erofs_xattr_prefix_item *pf; > + char *ishare_key; > + > + if (!sbi->xattr_prefixes || > + !(sbi->ishare_key_start & EROFS_XATTR_LONG_PREFIX)) > + return 0; > + > + pf = sbi->xattr_prefixes + > + (sbi->ishare_key_start & EROFS_XATTR_LONG_PREFIX_MASK); > + if (!pf || pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) > + return 0; > + ishare_key = kmalloc(pf->infix_len + 1, GFP_KERNEL); > + if (!ishare_key) > + return -ENOMEM; > + memcpy(ishare_key, pf->prefix->infix, pf->infix_len); > + ishare_key[pf->infix_len] = '\0'; > + sbi->ishare_key = ishare_key; > + sbi->ishare_key_idx = pf->prefix->base_index; > + return 0; > +} > +#endif > diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h > index 6317caa8413e..21684359662c 100644 > --- a/fs/erofs/xattr.h > +++ b/fs/erofs/xattr.h > @@ -67,4 +67,10 @@ struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu); > #define erofs_get_acl (NULL) > #endif > > +#ifdef CONFIG_EROFS_FS_INODE_SHARE > +int erofs_xattr_set_ishare_key(struct super_block *sb); > +#else > +static inline int erofs_xattr_set_ishare_key(struct super_block *sb) { return 0; } > +#endif > + > #endif