linux-ext4 - Re: [PATCH 4/4] ext4: fix suboptimal seek

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Message-ID: <20141202230730.GH13618@thunk.org>
Date:	Tue, 2 Dec 2014 18:07:30 -0500
From:	Theodore Ts'o <tytso@....edu>
To:	Dmitry Monakhov <dmonakhov@...nvz.org>
Cc:	linux-ext4@...r.kernel.org
Subject: Re: [PATCH 4/4] ext4: fix suboptimal seek_{data,hole} extents
 traversial

On Tue, Dec 02, 2014 at 03:00:54PM +0400, Dmitry Monakhov wrote:
> It is rediculus practice to scan inode block by block, this technique
> applicable only for old indirect files. This takes signifficant amount
> of time for really large files. Let's reuse ext4_fiemap which already
> traverse inode-tree in most optimal meaner.
> 
> TESTCASE:
> ftruncate64(fd, 0);
> ftruncate64(fd, 1ULL << 40);
> /* lseek will spin very long time */
> lseek64(fd, 0, SEEK_DATA);
> lseek64(fd, 0, SEEK_HOLE);

Thanks, applied.

						- Ted
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