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authorNicholas Bellinger <nab@linux-iscsi.org>2015-07-23 09:14:19 +0300
committerNicholas Bellinger <nab@linux-iscsi.org>2015-07-25 00:19:43 +0300
commite54198657b65625085834847ab6271087323ffea (patch)
treecd51f1a28f009c7f4ed97152a6a9ee245bd64d5d /drivers/target/iscsi/iscsi_target_nego.c
parent417c20a9bdd1e876384127cf096d8ae8b559066c (diff)
downloadlinux-e54198657b65625085834847ab6271087323ffea.tar.xz
iscsi-target: Fix iscsit_start_kthreads failure OOPs
This patch fixes a regression introduced with the following commit in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers a NULL pointer dereference OOPs: commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca Author: Nicholas Bellinger <nab@linux-iscsi.org> Date: Thu Feb 26 22:19:15 2015 -0800 iscsi-target: Convert iscsi_thread_set usage to kthread.h To address this bug, move iscsit_start_kthreads() immediately preceeding the transmit of last login response, before signaling a successful transition into full-feature-phase within existing iscsi_target_do_tx_login_io() logic. This ensures that no target-side resource allocation failures can occur after the final login response has been successfully sent. Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread to sleep to prevent other socket related failures until the final iscsi_post_login_handler() call is able to complete. Cc: Sagi Grimberg <sagig@mellanox.com> Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/iscsi/iscsi_target_nego.c')
-rw-r--r--drivers/target/iscsi/iscsi_target_nego.c34
1 files changed, 33 insertions, 1 deletions
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index 8c02fa34716f..f9cde9141836 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -17,6 +17,7 @@
******************************************************************************/
#include <linux/ctype.h>
+#include <linux/kthread.h>
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
@@ -361,10 +362,24 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
ntohl(login_rsp->statsn), login->rsp_length);
padding = ((-login->rsp_length) & 3);
+ /*
+ * Before sending the last login response containing the transition
+ * bit for full-feature-phase, go ahead and start up TX/RX threads
+ * now to avoid potential resource allocation failures after the
+ * final login response has been sent.
+ */
+ if (login->login_complete) {
+ int rc = iscsit_start_kthreads(conn);
+ if (rc) {
+ iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+ ISCSI_LOGIN_STATUS_NO_RESOURCES);
+ return -1;
+ }
+ }
if (conn->conn_transport->iscsit_put_login_tx(conn, login,
login->rsp_length + padding) < 0)
- return -1;
+ goto err;
login->rsp_length = 0;
mutex_lock(&sess->cmdsn_mutex);
@@ -373,6 +388,23 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
mutex_unlock(&sess->cmdsn_mutex);
return 0;
+
+err:
+ if (login->login_complete) {
+ if (conn->rx_thread && conn->rx_thread_active) {
+ send_sig(SIGINT, conn->rx_thread, 1);
+ kthread_stop(conn->rx_thread);
+ }
+ if (conn->tx_thread && conn->tx_thread_active) {
+ send_sig(SIGINT, conn->tx_thread, 1);
+ kthread_stop(conn->tx_thread);
+ }
+ spin_lock(&iscsit_global->ts_bitmap_lock);
+ bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
+ get_order(1));
+ spin_unlock(&iscsit_global->ts_bitmap_lock);
+ }
+ return -1;
}
static void iscsi_target_sk_data_ready(struct sock *sk)