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From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Eric Biggers <ebiggers@kernel.org>
Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org, Victor Hsieh <victorhsieh@google.com>,
	linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [PATCH v2] fs-verity: implement readahead of Merkle tree pages
Date: Mon, 13 Jan 2020 19:14:07 -0500
Message-ID: <20200114001407.GO76141@mit.edu> (raw)
In-Reply-To: <20200106205533.137005-1-ebiggers@kernel.org>

On Mon, Jan 06, 2020 at 12:55:33PM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> When fs-verity verifies data pages, currently it reads each Merkle tree
> page synchronously using read_mapping_page().
> 
> Therefore, when the Merkle tree pages aren't already cached, fs-verity
> causes an extra 4 KiB I/O request for every 512 KiB of data (assuming
> that the Merkle tree uses SHA-256 and 4 KiB blocks).  This results in
> more I/O requests and performance loss than is strictly necessary.
> 
> Therefore, implement readahead of the Merkle tree pages.

Looks good.   Feel free to add:

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

(for the ext4 and fs/verity bits)


  parent reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-06 20:55 Eric Biggers
2020-01-13 19:25 ` Eric Biggers
2020-01-14  0:14 ` Theodore Y. Ts'o [this message]
2020-01-14 21:31 ` [f2fs-dev] " Eric Biggers

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