[PATCH 3.16 235/305] Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()

[Ben Hutchings]

3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Dexuan Cui <decui@xxxxxxxxxxxxx>

commit eceb05965489784f24bbf4d61ba60e475a983016 upstream.

This is a longstanding issue: if the vmbus upper-layer drivers try to
consume too many GPADLs, the host may return with an error
0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check
the creation_status, and hence we can pass an invalid GPADL handle
into the OPEN_CHANNEL message, and get an error code 0xc0000225 in
open_info->response.open_result.status, and finally we hang in
vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl().

With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED.

Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/hv/channel.c | 8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -416,6 +416,14 @@ int vmbus_establish_gpadl(struct vmbus_c
 	}
 	wait_for_completion(&msginfo->waitevent);
 
+	if (msginfo->response.gpadl_created.creation_status != 0) {
+		pr_err("Failed to establish GPADL: err = 0x%x\n",
+		       msginfo->response.gpadl_created.creation_status);
+
+		ret = -EDQUOT;
+		goto cleanup;
+	}
+
 	/* At this point, we received the gpadl created msg */
 	*gpadl_handle = gpadlmsg->gpadl;