[PATCH] vfs: Fix vmtruncate() regression
OGAWA Hirofumi
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: sta...@kernel.org
Signed-off-by: OGAWA Hirofumi <hiro...@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 <hiro...@mail.parknet.co.jp>
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Nick Piggin
> 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: sta...@kernel.org
> Signed-off-by: OGAWA Hirofumi <hiro...@mail.parknet.co.jp>
Hmm, truncate_pagecache() is for truncating the mm/vm part of the
pagecache. vmtruncate should still call inode->i_op->truncate() to
trim blocks if required.
However I'd say we do still need to ensure do_invalidatepage is
called for the page, for private metadata. So yes I think your patch
looks good.
Acked-by: Nick Piggin <npi...@suse.de>
Please apply to mainline and 2.6.32.
OGAWA Hirofumi
>> 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: sta...@kernel.org
>> Signed-off-by: OGAWA Hirofumi <hiro...@mail.parknet.co.jp>
>
> Hmm, truncate_pagecache() is for truncating the mm/vm part of the
> pagecache. vmtruncate should still call inode->i_op->truncate() to
> trim blocks if required.
>
> However I'd say we do still need to ensure do_invalidatepage is
> called for the page, for private metadata. So yes I think your patch
> looks good.
Thanks for reviewing. Yes, and it also needs to be called to ensure that
have the same state on-disk and page/bh state. [BTW, this became the
cause of fatfs corruption.]
Thanks.
OGAWA Hirofumi
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.
Acked-by: Nick Piggin <npi...@suse.de>
Signed-off-by: OGAWA Hirofumi <hiro...@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 05:43:06.000000000 +0900
+++ linux-2.6-hirofumi/mm/truncate.c 2010-01-12 05:43:06.000000000 +0900
Andrew Morton
The fix was applied to 2.6.33-rcX
(cedabed49b39b4319bccc059a63344b6232b619c), appears to be needed in
2.6.32.x but no cc:stable's are present?
OGAWA Hirofumi
Ah, yes. I forgot to add "Cc: stable". Please apply this to 2.6.32.x.
--
OGAWA Hirofumi <hiro...@mail.parknet.co.jp>
Nick Piggin
Thanks guys, it's quite important so please apply to stable 2.6.32 and
consider it as a high priority to release.
Greg KH
Now queued up for the next .32 -stable release.
greg k-h