[PATCH] generic/465: fix a read bug when encounter EOF

[Su Yanjun <suyj.fnst@cn.fujitsu.com>]

In nfs test, if the writer has not written enough data for reader reading,
then reader only get partial data and test fails.

We can continue reading until read enough data.

Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com>
---
 src/aio-dio-regress/aio-dio-append-write-read-race.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/aio-dio-regress/aio-dio-append-write-read-race.c b/src/aio-dio-regress/aio-dio-append-write-read-race.c
index 911f272..f28ef3c 100644
--- a/src/aio-dio-regress/aio-dio-append-write-read-race.c
+++ b/src/aio-dio-regress/aio-dio-append-write-read-race.c
@@ -44,14 +44,27 @@ static void usage(const char *prog)
 static void *reader(void *arg)
 {
 	struct io_data *data = (struct io_data *)arg;
+	size_t blksize = data->blksize;
+	size_t offset = data->offset;
+	char   *buf = data->buf;
 
 	memset(data->buf, 'b', data->blksize);
 	reader_ready = 1;
 	do {
-		data->read_sz = pread(data->fd, data->buf, data->blksize,
-				      data->offset);
+		data->read_sz = pread(data->fd, buf, blksize,
+				      offset);
 		if (data->read_sz < 0)
 			perror("read file");
+
+		if (data->read_sz > 0) {
+			blksize -= data->read_sz;
+			offset  += data->read_sz;
+			buf	+= data->read_sz;
+			data->read_sz = 0;
+		}
+
+		if (blksize <= 0)
+			break;
 	} while (data->read_sz <= 0);
 
 	return NULL;
-- 
2.7.4