fs: Do to trim high file position bits in iomap_page_mkwrite_actor
iomap_page_mkwrite_actor() calls __block_write_begin_int() with position
masked as pos & ~PAGE_MASK which is equivalent to pos & (PAGE_SIZE-1).
Thus it masks off high bits of file position. However
__block_write_begin_int() expects full file position on input. This does
not cause any visible issues because all __block_write_begin_int()
really cares about are low file position bits but still it is a bug
waiting to happen.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/iomap.c b/fs/iomap.c
index a922040..a8ee8c3 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -433,8 +433,7 @@
struct page *page = data;
int ret;
- ret = __block_write_begin_int(page, pos & ~PAGE_MASK, length,
- NULL, iomap);
+ ret = __block_write_begin_int(page, pos, length, NULL, iomap);
if (ret)
return ret;