[PATCH] ecryptfs remove unnecessary flush_dcache_page

[Dmitriy Monakhov <dmonakhov@sw.ru>]

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Dmitriy Monakhov <dmonakhov@openvz.org> writes:

> 1)Function ecryptfs_do_readpage() calls flush_dcache_page(lower_page),
>   but lower_page was't changed here. So remove this line.
>
> 2)prepare_write ret val was ignored in ecryptfs_write_inode_size_to_header().
> If error happends we can't call commit_write, just do cleanup and fial.
> It is issue easy to reproduce with full lower_fs, in this case prepare_write()
Second issue was fixed by "ecryptfs-resolve-lower-page-unlocking-problem.patch",
but first issue was't.

[LOG]
  Function ecryptfs_do_readpage() calls flush_dcache_page(lower_page),
  but lower_page was't changed here. Even if it was changed by 
  lower_a_ops->readpage() dcache was flushed by readpage() itself.
  So remove this unnecessary line.
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>


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diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 1e5d2ba..2e45513 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -238,7 +238,6 @@ int ecryptfs_do_readpage(struct file *file, struct page *page,
 	lower_page_data = kmap_atomic(lower_page, KM_USER1);
 	memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
 	kunmap_atomic(lower_page_data, KM_USER1);
-	flush_dcache_page(lower_page);
 	kunmap_atomic(page_data, KM_USER0);
 	flush_dcache_page(page);
 	rc = 0;