[PATCH] fs: ramfs: file-nommu: add SetPageUptodate()

[PATCH] fs: ramfs: file-nommu: add SetPageUptodate()

[Bob Liu]

There is a bug in below scene for platform !CONFIG_MMU:
1. create a new file
2. mmap the file and write to it
3. read the file can't get the correct value

Because
sys_read() > generic_file_aio_read() > simple_readpage() > clear_page()
which make the page be zeroed.

Add SetPageUptodate() to ramfs_nommu_expand_for_mapping() so that
generic_file_aio_read() do not call simple_readpage().

Signed-off-by: Bob Liu <lliubbo@gmail.com>
---
 fs/ramfs/file-nommu.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index fbb0b47..d5378d0 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -110,6 +110,7 @@ int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize)
 
 		/* prevent the page from being discarded on memory pressure */
 		SetPageDirty(page);
+		SetPageUptodate(page);
 
 		unlock_page(page);
 		put_page(page);
-- 
1.7.9.5


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