From: Gao Xiang <gaoxiang25@huawei.com>
To: "Theodore Y. Ts'o" <tytso@mit.edu>,
Eric Biggers <ebiggers@kernel.org>,
<linux-fsdevel@vger.kernel.org>, <linux-ext4@vger.kernel.org>,
<linux-f2fs-devel@lists.sourceforge.net>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
Michael Halcrow <mhalcrow@google.com>,
<linux-kernel@vger.kernel.org>, <linux-fscrypt@vger.kernel.org>,
<linux-integrity@vger.kernel.org>,
Mimi Zohar <zohar@linux.vnet.ibm.com>,
Victor Hsieh <victorhsieh@google.com>
Subject: Re: [f2fs-dev] [RFC PATCH 02/10] fs-verity: add data verification hooks for ->readpages()
Date: Sat, 25 Aug 2018 12:00:04 +0800 [thread overview]
Message-ID: <cb646950-94ea-9b28-80f1-3c840ad85581@huawei.com> (raw)
In-Reply-To: <20180825034544.GA5281@thunk.org>
Hi Ted,
On 2018/8/25 11:45, Theodore Y. Ts'o wrote:
> On Sat, Aug 25, 2018 at 10:29:26AM +0800, Gao Xiang wrote:
>> My first question is that 'Is there any way to skip to verify pages in a bio?'
>> I am thinking about
>> If metadata and data page are mixed in a filesystem of such kind, they could submit together in a bio, but metadata could be unsuitable for such kind of verification.
>>
>> The second question is related to the first question --- 'Is there any way to verify a partial page?'
>> Take scalability into consideration, some files could be totally inlined or partially inlined in metadata.
>> Is there any way to deal with them in per-file approach? at least --- support for the interface?
> A requirement of both fscrypt and fsverity is that is that block size
> == page size, and that all data is stored in blocks. Inline data is
> not supported.
>
> The files that are intended for use with fsverity are large files
> (such as APK files), so optimizing for files smaller than a block was
> not a design goal.
Thanks for your quickly reply. :)
I had seen the background of why Google/Android introduces fs-verity before.
>
But I have some consideration than the current implementation.... (if it is suitable to discuss, thanks...)
1) Since it is the libfs-like library, I think bio-strict is too strict for its future fs users.
bios could be already organized in filesystem-specific way, which could include some other pages that is unnecessary to be verified.
I could give some example, if some filesystem organizes its bios for decompression, and some data exist in metadata.
It could be hard to use this libfs-like fsverity interface.
2) My last question
"At last, I hope filesystems could select the on-disk position of hash tree and 'struct fsverity_descriptor'
rather than fixed in the end of verity files...I think if fs-verity preparing such support and interfaces could be better....."
is also for some files partially or totally encoded (eg. compressed, or whatever ...)
I think the hash tree is unnecessary to be compressed...so I think it could be better that it can be selected by users (filesystems of course).
Thanks,
Gao Xiang.
> - Ted
next prev parent reply other threads:[~2018-08-25 4:00 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-24 16:16 [RFC PATCH 00/10] fs-verity: filesystem-level integrity protection Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 01/10] fs-verity: add setup code, UAPI, and Kconfig Eric Biggers
2018-08-24 17:28 ` Randy Dunlap
2018-08-24 17:42 ` Colin Walters
2018-08-24 22:45 ` Theodore Y. Ts'o
2018-08-25 4:48 ` Eric Biggers
2018-09-14 13:15 ` Colin Walters
2018-09-14 16:21 ` Eric Biggers
2018-09-15 15:27 ` Theodore Y. Ts'o
2018-08-26 16:22 ` Chuck Lever
2018-08-26 17:17 ` Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 02/10] fs-verity: add data verification hooks for ->readpages() Eric Biggers
2018-08-25 2:29 ` [f2fs-dev] " Gao Xiang
2018-08-25 3:45 ` Theodore Y. Ts'o
2018-08-25 4:00 ` Gao Xiang [this message]
2018-08-25 5:06 ` Theodore Y. Ts'o
2018-08-25 7:33 ` Gao Xiang
2018-08-25 7:55 ` Gao Xiang
2018-08-25 4:16 ` Eric Biggers
2018-08-25 6:31 ` Gao Xiang
2018-08-25 7:18 ` Eric Biggers
2018-08-25 7:43 ` Gao Xiang
2018-08-25 17:06 ` Theodore Y. Ts'o
2018-08-26 13:44 ` Gao Xiang
2018-09-02 2:35 ` Olof Johansson
2018-08-26 15:55 ` Chuck Lever
2018-08-26 17:04 ` Eric Biggers
2018-08-26 17:44 ` Gao Xiang
2018-08-24 16:16 ` [RFC PATCH 03/10] fs-verity: implement FS_IOC_ENABLE_VERITY ioctl Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 04/10] fs-verity: implement FS_IOC_MEASURE_VERITY ioctl Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 05/10] fs-verity: add SHA-512 support Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 06/10] fs-verity: add CRC-32C support Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 07/10] fs-verity: support builtin file signatures Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 08/10] ext4: add basic fs-verity support Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 09/10] ext4: add fs-verity read support Eric Biggers
2018-08-24 16:16 ` [RFC PATCH 10/10] f2fs: fs-verity support Eric Biggers
2018-08-25 5:54 ` [f2fs-dev] " Chao Yu
2018-08-26 17:35 ` Eric Biggers
2018-08-27 15:54 ` Chao Yu
2018-08-28 7:27 ` Jaegeuk Kim
2018-08-28 9:20 ` Chao Yu
2018-08-28 17:01 ` Jaegeuk Kim
2018-08-29 1:22 ` Chao Yu
2018-08-29 1:43 ` Jaegeuk Kim
2018-08-31 20:05 ` [RFC PATCH 00/10] fs-verity: filesystem-level integrity protection Jan Lübbe
2018-08-31 21:39 ` Eric Biggers
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