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| author | Bob Liu <lliubbo@gmail.com> | 2012-07-11 14:02:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-16 09:04:45 -0700 |
| commit | 0fa627b15c842095b5147f381fa1943a6a46bb01 (patch) | |
| tree | 4293cc0156d458583829aefff1eee7daa56df5fe | |
| parent | 7a08b440fa93e036968102597c8a2ab809a9bdc4 (diff) | |
| download | linux-3.10-0fa627b15c842095b5147f381fa1943a6a46bb01.tar.gz linux-3.10-0fa627b15c842095b5147f381fa1943a6a46bb01.tar.bz2 linux-3.10-0fa627b15c842095b5147f381fa1943a6a46bb01.zip | |
fs: ramfs: file-nommu: add SetPageUptodate()
commit fea9f718b3d68147f162ed2d870183ce5e0ad8d8 upstream.
There is a bug in the below scenario for !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 causes the page to 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>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
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@linuxfoundation.org>
| -rw-r--r-- | fs/ramfs/file-nommu.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index fbb0b478a34..d5378d02858 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); |