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* [PATCH] vfs: Fix vmtruncate() regression
@ 2010-01-11 18:40 OGAWA Hirofumi
  2010-01-13  6:07 ` Nick Piggin
  0 siblings, 1 reply; 8+ messages in thread
From: OGAWA Hirofumi @ 2010-01-11 18:40 UTC (permalink / raw)
  To: Al Viro, Nick Piggin; +Cc: linux-kernel, linux-fsdevel

Hi,

Could you review this one?



If __block_prepare_write() was failed in block_write_begin(), the
allocated blocks can be outside of ->i_size.

But new truncate_pagecache() in vmtuncate() does nothing if new < old.
It means the above usage is not working anymore.

So, this patch fixes it by removing "new < old" check. It would need
more cleanup/change. But, now -rc and truncate working is in progress,
so, this tried to fix it minimum change.

Cc: stable@kernel.org
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---

 mm/truncate.c |   28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff -puN mm/truncate.c~truncate_pagecache-fix mm/truncate.c
--- linux-2.6/mm/truncate.c~truncate_pagecache-fix	2010-01-12 02:41:27.000000000 +0900
+++ linux-2.6-hirofumi/mm/truncate.c	2010-01-12 02:42:53.000000000 +0900
@@ -522,22 +522,20 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages
  */
 void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
 {
-	if (new < old) {
-		struct address_space *mapping = inode->i_mapping;
+	struct address_space *mapping = inode->i_mapping;
 
-		/*
-		 * unmap_mapping_range is called twice, first simply for
-		 * efficiency so that truncate_inode_pages does fewer
-		 * single-page unmaps.  However after this first call, and
-		 * before truncate_inode_pages finishes, it is possible for
-		 * private pages to be COWed, which remain after
-		 * truncate_inode_pages finishes, hence the second
-		 * unmap_mapping_range call must be made for correctness.
-		 */
-		unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
-		truncate_inode_pages(mapping, new);
-		unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
-	}
+	/*
+	 * unmap_mapping_range is called twice, first simply for
+	 * efficiency so that truncate_inode_pages does fewer
+	 * single-page unmaps.  However after this first call, and
+	 * before truncate_inode_pages finishes, it is possible for
+	 * private pages to be COWed, which remain after
+	 * truncate_inode_pages finishes, hence the second
+	 * unmap_mapping_range call must be made for correctness.
+	 */
+	unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+	truncate_inode_pages(mapping, new);
+	unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
 }
 EXPORT_SYMBOL(truncate_pagecache);
 
_

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2010-01-19 23:52 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-01-11 18:40 [PATCH] vfs: Fix vmtruncate() regression OGAWA Hirofumi
2010-01-13  6:07 ` Nick Piggin
2010-01-13 12:07   ` OGAWA Hirofumi
2010-01-13 12:14     ` OGAWA Hirofumi
2010-01-14 22:30       ` Andrew Morton
2010-01-15  0:26         ` OGAWA Hirofumi
2010-01-18  3:51           ` Nick Piggin
2010-01-19 23:52             ` [stable] " Greg KH

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