From: Eric Sandeen <sandeen@sandeen.net>
Date: Wed, 29 Jul 2009 22:02:16 +0000 (-0700)
Subject: hugetlbfs: fix i_blocks accounting
X-Git-Tag: v2.6.27.30~27
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7514a6632bbf548999869dc7d873f52ddf917856;p=pandora-kernel.git

hugetlbfs: fix i_blocks accounting

commit e4c6f8bed01f9f9a5c607bd689bf67e7b8a36bd8 upstream.

As reported in Red Hat bz #509671, i_blocks for files on hugetlbfs get
accounting wrong when doing something like:

   $ > foo
   $ date  > foo
   date: write error: Invalid argument
   $ /usr/bin/stat foo
     File: `foo'
     Size: 0          Blocks: 18446744073709547520 IO Block: 2097152 regular
...

This is because hugetlb_unreserve_pages() is unconditionally removing
blocks_per_huge_page(h) on each call rather than using the freed amount.
If there were 0 blocks, it goes negative, resulting in the above.

This is a regression from commit a5516438959d90b071ff0a484ce4f3f523dc3152
("hugetlb: modular state for hugetlb page size")

which did:

-	inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed;
+	inode->i_blocks -= blocks_per_huge_page(h);

so just put back the freed multiplier, and it's all happy again.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

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