[dm-devel] [PATCH] convert dm_ulog_request data to little endian

[Dongmao Zhang]

the dm_ulog_request might be little endian or big endian depending on
the architecture. This is not right. This patch is to convert
dm_ulog_request to little endian.

I met a bug when running cmirrord on s390 linux

Signed-off-by: Dongmao Zhang <dmzhang at suse.com>
---
 drivers/md/dm-log-userspace-transfer.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index b428c0a..cddef2f 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -53,6 +53,29 @@ struct receiving_pkg {
 static DEFINE_SPINLOCK(receiving_list_lock);
 static struct list_head receiving_list;
 
+static void cpu_to_network(struct dm_ulog_request *tfr)
+{
+	if (tfr == NULL)
+		return;
+	tfr->luid = cpu_to_le64(tfr->luid);
+	tfr->version =  cpu_to_le32(tfr->version);
+	tfr->seq = cpu_to_le32(tfr->seq);
+	tfr->request_type = cpu_to_le32(tfr->request_type);
+	tfr->data_size = cpu_to_le32(tfr->data_size);
+}
+
+static void network_to_cpu(struct dm_ulog_request *tfr)
+{
+	if (tfr == NULL)
+		return;
+	tfr->luid = le64_to_cpu(tfr->luid);
+	tfr->version =  le32_to_cpu(tfr->version);
+	tfr->seq = le32_to_cpu(tfr->seq);
+	tfr->request_type = le32_to_cpu(tfr->request_type);
+	tfr->data_size = le32_to_cpu(tfr->data_size);
+	tfr->error = le32_to_cpu(tfr->error);
+}
+
 static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
 {
 	int r;
@@ -66,6 +89,7 @@ static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
 	msg->seq = tfr->seq;
 	msg->len = sizeof(struct dm_ulog_request) + tfr->data_size;
 
+	cpu_to_network(tfr);
 	r = cn_netlink_send(msg, 0, 0, gfp_any());
 
 	return r;
@@ -81,8 +105,11 @@ static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
  */
 static int fill_pkg(struct cn_msg *msg, struct dm_ulog_request *tfr)
 {
-	uint32_t rtn_seq = (msg) ? msg->seq : (tfr) ? tfr->seq : 0;
 	struct receiving_pkg *pkg;
+	uint32_t rtn_seq;
+
+	network_to_cpu(tfr);
+	rtn_seq = (msg) ? msg->seq : (tfr) ? tfr->seq : 0;
 
 	/*
 	 * The 'receiving_pkg' entries in this list are statically
@@ -148,6 +175,8 @@ static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 	spin_unlock(&receiving_list_lock);
 }
 
+
+
 /**
  * dm_consult_userspace
  * @uuid: log's universal unique identifier (must be DM_UUID_LEN in size)
-- 
1.8.4.5