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From: Eric Sandeen <sandeen@redhat.com>
To: ext4 development <linux-ext4@vger.kernel.org>
Subject: Where all does preallocated/extra space hide?
Date: Tue, 29 Sep 2009 11:47:19 -0500	[thread overview]
Message-ID: <4AC23A17.5020100@redhat.com> (raw)

I was running some of the xfstests enospc tests on ext4, and they were
failing; in one case, manymanymany small files are made to fill up a
100M filesystem.  ext4 stops quite early with -ENOSPC, but after a bit,
(or after a "sync") we get 40MB free again.  So 40% of the fs space is
hidden somewhere in preallocation...

I tried calling out to discard group prealloc but that's only a few
blocks.  I'll go trace through the sync paths to see what all gets
released, but if anyone knows offhand where the rest of that space is
hiding, please give me a shout.  :)

Thanks,
-Eric

             reply	other threads:[~2009-09-29 16:47 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-29 16:47 Eric Sandeen [this message]
2009-10-01 16:55 ` Where all does preallocated/extra space hide? Eric Sandeen
2009-10-08 11:48 ` Aneesh Kumar K.V
2009-10-08 15:56   ` Eric Sandeen
2009-10-09  5:27     ` Aneesh Kumar K.V
2009-10-09 14:51       ` Eric Sandeen

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