[PATCH]fs/block_dev.c: fix the inaccurate judgement in function blkdev_aio_read

[Gu Zheng <guz.fnst@cn.fujitsu.com>]

In function blkdev_aio_read(), the judgement of 'size', if it is equal or greater than
the target count we request(iocb->ki_left), there is no need to call iov_shorten() to
reduce number of segments and the iovec's length.
So the judgement should be changed to 'if (size < iocb->ki_left)' instead.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
---
 fs/block_dev.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index aae187a..f0328f1 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1559,7 +1559,7 @@ static ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
                return 0;
 
        size -= pos;
-       if (size < INT_MAX)
+       if (size < iocb->ki_left)
                nr_segs = iov_shorten((struct iovec *)iov, nr_segs, size);
        return generic_file_aio_read(iocb, iov, nr_segs, pos);
 }
-- 
1.7.7