[PATCH 4.19 131/247] IB/umad: Return EIO in case of when device disassociated

[Greg Kroah-Hartman]

From: Shay Drory <shayd@xxxxxxxxxx>

[ Upstream commit 4fc5461823c9cad547a9bdfbf17d13f0da0d6bb5 ]

MAD message received by the user has EINVAL error in all flows
including when the device is disassociated. That makes it impossible
for the applications to treat such flow differently.

Change it to return EIO, so the applications will be able to perform
disassociation recovery.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/r/20210125121339.837518-2-leon@xxxxxxxxxx
Signed-off-by: Shay Drory <shayd@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/core/user_mad.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index a18f3f8ad77fe..db2ac5218c371 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -366,6 +366,11 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
 
 	mutex_lock(&file->mutex);
 
+	if (file->agents_dead) {
+		mutex_unlock(&file->mutex);
+		return -EIO;
+	}
+
 	while (list_empty(&file->recv_list)) {
 		mutex_unlock(&file->mutex);
 
@@ -508,7 +513,7 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 
 	agent = __get_agent(file, packet->mad.hdr.id);
 	if (!agent) {
-		ret = -EINVAL;
+		ret = -EIO;
 		goto err_up;
 	}
 
-- 
2.27.0