linux-kernel - Re: [PATCH v15 5/9] erofs: introduce the page cache share feature

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ffdfbf7c-25fc-47ca-8c90-c98301847a1f@huawei.com>
Date: Thu, 22 Jan 2026 22:48:27 +0800
From: Hongbo Li <lihongbo22@...wei.com>
To: Christoph Hellwig <hch@....de>
CC: <hsiangkao@...ux.alibaba.com>, <chao@...nel.org>, <brauner@...nel.org>,
	<djwong@...nel.org>, <amir73il@...il.com>, <linux-fsdevel@...r.kernel.org>,
	<linux-erofs@...ts.ozlabs.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v15 5/9] erofs: introduce the page cache share feature



On 2026/1/20 20:29, Hongbo Li wrote:
> 
> 
> On 2026/1/16 23:46, Christoph Hellwig wrote:
>> I don't really understand the fingerprint idea.  Files with the
>> same content will point to the same physical disk blocks, so that
>> should be a much better indicator than a finger print?  Also how does
>> the fingerprint guarantee uniqueness?  Is it a cryptographically
>> secure hash?  In here it just seems like an opaque blob.
>>
>>> +static inline int erofs_inode_set_aops(struct inode *inode,
>>> +                       struct inode *realinode, bool no_fscache)
>>
>> Factoring this out first would be a nice little prep patch.
>> Also it would probably be much cleaner using IS_ENABLED.
> 
> Ok, Thanks for reviewing. I will refine in next version.

Sorry I overlooked this point. Factoring this out is a good idea, but we 
cannot use IS_ENABLED here, because some aops is not visible  when the 
relevant config macro is not enabled. So I choose to keep this format 
and only to factor this out.

Thanks,
Hongbo

> 
> Thanks,
> Hongbo
> 
>>
>>> +static int erofs_ishare_file_open(struct inode *inode, struct file 
>>> *file)
>>> +{
>>> +    struct inode *sharedinode = EROFS_I(inode)->sharedinode;
>>
>> Ok, it looks like this allocates a separate backing file and inode.
>>