[PATCH AUTOSEL 6.4 09/54] 9p: virtio: fix unlikely null pointer deref in handle_rerror

[PATCH AUTOSEL 6.4 09/54] 9p: virtio: fix unlikely null pointer deref in handle_rerror

[Sasha Levin]

From: Dominique Martinet <asmadeus@codewreck.org>

[ Upstream commit 13ade4ac5c28e8a014fa85278f5a4270b215f906 ]

handle_rerror can dereference the pages pointer, but it is not
necessarily set for small payloads.
In practice these should be filtered out by the size check, but
might as well double-check explicitly.

This fixes the following scan-build warnings:
net/9p/trans_virtio.c:401:24: warning: Dereference of null pointer [core.NullDereference]
                memcpy_from_page(to, *pages++, offs, n);
                                     ^~~~~~~~
net/9p/trans_virtio.c:406:23: warning: Dereference of null pointer (loaded from variable 'pages') [core.NullDereference]
        memcpy_from_page(to, *pages, offs, size);
                             ^~~~~~

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/9p/trans_virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 3c27ffb781e3e..2c9495ccda6ba 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -384,7 +384,7 @@ static void handle_rerror(struct p9_req_t *req, int in_hdr_len,
 	void *to = req->rc.sdata + in_hdr_len;
 
 	// Fits entirely into the static data?  Nothing to do.
-	if (req->rc.size < in_hdr_len)
+	if (req->rc.size < in_hdr_len || !pages)
 		return;
 
 	// Really long error message?  Tough, truncate the reply.  Might get
-- 
2.40.1

[PATCH AUTOSEL 6.4 10/54] 9p: virtio: make sure 'offs' is initialized in zc_request

[Sasha Levin]

From: Dominique Martinet <asmadeus@codewreck.org>

[ Upstream commit 4a73edab69d3a6623f03817fe950a2d9585f80e4 ]

Similarly to the previous patch: offs can be used in handle_rerrors
without initializing on small payloads; in this case handle_rerrors will
not use it because of the size check, but it doesn't hurt to make sure
it is zero to please scan-build.

This fixes the following warning:
net/9p/trans_virtio.c:539:3: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
                handle_rerror(req, in_hdr_len, offs, in_pages);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/9p/trans_virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 2c9495ccda6ba..f3f6782894239 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -428,7 +428,7 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
 	struct page **in_pages = NULL, **out_pages = NULL;
 	struct virtio_chan *chan = client->trans;
 	struct scatterlist *sgs[4];
-	size_t offs;
+	size_t offs = 0;
 	int need_drop = 0;
 	int kicked = 0;
 
-- 
2.40.1

[PATCH AUTOSEL 6.4 19/54] net: hns3: add tm flush when setting tm

[Sasha Levin]

From: Hao Lan <lanhao@huawei.com>

[ Upstream commit 6d2336120aa6e1a8a64fa5d6ee5c3f3d0809fe9b ]

When the tm module is configured with traffic, traffic
may be abnormal. This patch fixes this problem.
Before the tm module is configured, traffic processing
should be stopped. After the tm module is configured,
traffic processing is enabled.

Signed-off-by: Hao Lan <lanhao@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/hisilicon/hns3/hnae3.h   |  4 +++
 .../hns3/hns3_common/hclge_comm_cmd.c         |  1 +
 .../hns3/hns3_common/hclge_comm_cmd.h         |  2 ++
 .../ethernet/hisilicon/hns3/hns3_debugfs.c    |  3 ++
 .../hisilicon/hns3/hns3pf/hclge_dcb.c         | 34 ++++++++++++++++---
 .../ethernet/hisilicon/hns3/hns3pf/hclge_tm.c | 31 ++++++++++++++++-
 .../ethernet/hisilicon/hns3/hns3pf/hclge_tm.h |  4 +++
 7 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h
index 9c9c72dc57e00..0f01e58f95c99 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h
@@ -101,6 +101,7 @@ enum HNAE3_DEV_CAP_BITS {
 	HNAE3_DEV_SUPPORT_FEC_STATS_B,
 	HNAE3_DEV_SUPPORT_LANE_NUM_B,
 	HNAE3_DEV_SUPPORT_WOL_B,
+	HNAE3_DEV_SUPPORT_TM_FLUSH_B,
 };
 
 #define hnae3_ae_dev_fd_supported(ae_dev) \
@@ -172,6 +173,9 @@ enum HNAE3_DEV_CAP_BITS {
 #define hnae3_ae_dev_wol_supported(ae_dev) \
 	test_bit(HNAE3_DEV_SUPPORT_WOL_B, (ae_dev)->caps)
 
+#define hnae3_ae_dev_tm_flush_supported(hdev) \
+	test_bit(HNAE3_DEV_SUPPORT_TM_FLUSH_B, (hdev)->ae_dev->caps)
+
 enum HNAE3_PF_CAP_BITS {
 	HNAE3_PF_SUPPORT_VLAN_FLTR_MDF_B = 0,
 };
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.c b/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.c
index b85c412683ddc..40684743a4c6c 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.c
@@ -156,6 +156,7 @@ static const struct hclge_comm_caps_bit_map hclge_pf_cmd_caps[] = {
 	{HCLGE_COMM_CAP_FEC_STATS_B, HNAE3_DEV_SUPPORT_FEC_STATS_B},
 	{HCLGE_COMM_CAP_LANE_NUM_B, HNAE3_DEV_SUPPORT_LANE_NUM_B},
 	{HCLGE_COMM_CAP_WOL_B, HNAE3_DEV_SUPPORT_WOL_B},
+	{HCLGE_COMM_CAP_TM_FLUSH_B, HNAE3_DEV_SUPPORT_TM_FLUSH_B},
 };
 
 static const struct hclge_comm_caps_bit_map hclge_vf_cmd_caps[] = {
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.h b/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.h
index 18f1b4bf362da..2b7197ce0ae8f 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_common/hclge_comm_cmd.h
@@ -153,6 +153,7 @@ enum hclge_opcode_type {
 	HCLGE_OPC_TM_INTERNAL_STS	= 0x0850,
 	HCLGE_OPC_TM_INTERNAL_CNT	= 0x0851,
 	HCLGE_OPC_TM_INTERNAL_STS_1	= 0x0852,
+	HCLGE_OPC_TM_FLUSH		= 0x0872,
 
 	/* Packet buffer allocate commands */
 	HCLGE_OPC_TX_BUFF_ALLOC		= 0x0901,
@@ -349,6 +350,7 @@ enum HCLGE_COMM_CAP_BITS {
 	HCLGE_COMM_CAP_FEC_STATS_B = 25,
 	HCLGE_COMM_CAP_LANE_NUM_B = 27,
 	HCLGE_COMM_CAP_WOL_B = 28,
+	HCLGE_COMM_CAP_TM_FLUSH_B = 31,
 };
 
 enum HCLGE_COMM_API_CAP_BITS {
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
index 32bb14303473b..0811f9a4f9ee2 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c
@@ -411,6 +411,9 @@ static struct hns3_dbg_cap_info hns3_dbg_cap[] = {
 	}, {
 		.name = "support wake on lan",
 		.cap_bit = HNAE3_DEV_SUPPORT_WOL_B,
+	}, {
+		.name = "support tm flush",
+		.cap_bit = HNAE3_DEV_SUPPORT_TM_FLUSH_B,
 	}
 };
 
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_dcb.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_dcb.c
index c4aded65e848b..cda7e0d0ba56e 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_dcb.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_dcb.c
@@ -216,6 +216,10 @@ static int hclge_notify_down_uinit(struct hclge_dev *hdev)
 	if (ret)
 		return ret;
 
+	ret = hclge_tm_flush_cfg(hdev, true);
+	if (ret)
+		return ret;
+
 	return hclge_notify_client(hdev, HNAE3_UNINIT_CLIENT);
 }
 
@@ -227,6 +231,10 @@ static int hclge_notify_init_up(struct hclge_dev *hdev)
 	if (ret)
 		return ret;
 
+	ret = hclge_tm_flush_cfg(hdev, false);
+	if (ret)
+		return ret;
+
 	return hclge_notify_client(hdev, HNAE3_UP_CLIENT);
 }
 
@@ -313,6 +321,7 @@ static int hclge_ieee_setpfc(struct hnae3_handle *h, struct ieee_pfc *pfc)
 	struct net_device *netdev = h->kinfo.netdev;
 	struct hclge_dev *hdev = vport->back;
 	u8 i, j, pfc_map, *prio_tc;
+	int last_bad_ret = 0;
 	int ret;
 
 	if (!(hdev->dcbx_cap & DCB_CAP_DCBX_VER_IEEE))
@@ -350,13 +359,28 @@ static int hclge_ieee_setpfc(struct hnae3_handle *h, struct ieee_pfc *pfc)
 	if (ret)
 		return ret;
 
-	ret = hclge_buffer_alloc(hdev);
-	if (ret) {
-		hclge_notify_client(hdev, HNAE3_UP_CLIENT);
+	ret = hclge_tm_flush_cfg(hdev, true);
+	if (ret)
 		return ret;
-	}
 
-	return hclge_notify_client(hdev, HNAE3_UP_CLIENT);
+	/* No matter whether the following operations are performed
+	 * successfully or not, disabling the tm flush and notify
+	 * the network status to up are necessary.
+	 * Do not return immediately.
+	 */
+	ret = hclge_buffer_alloc(hdev);
+	if (ret)
+		last_bad_ret = ret;
+
+	ret = hclge_tm_flush_cfg(hdev, false);
+	if (ret)
+		last_bad_ret = ret;
+
+	ret = hclge_notify_client(hdev, HNAE3_UP_CLIENT);
+	if (ret)
+		last_bad_ret = ret;
+
+	return last_bad_ret;
 }
 
 static int hclge_ieee_setapp(struct hnae3_handle *h, struct dcb_app *app)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c
index 922c0da3660c7..c40ea6b8c8ec6 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.c
@@ -1484,7 +1484,11 @@ int hclge_tm_schd_setup_hw(struct hclge_dev *hdev)
 		return ret;
 
 	/* Cfg schd mode for each level schd */
-	return hclge_tm_schd_mode_hw(hdev);
+	ret = hclge_tm_schd_mode_hw(hdev);
+	if (ret)
+		return ret;
+
+	return hclge_tm_flush_cfg(hdev, false);
 }
 
 static int hclge_pause_param_setup_hw(struct hclge_dev *hdev)
@@ -2113,3 +2117,28 @@ int hclge_tm_get_port_shaper(struct hclge_dev *hdev,
 
 	return 0;
 }
+
+int hclge_tm_flush_cfg(struct hclge_dev *hdev, bool enable)
+{
+	struct hclge_desc desc;
+	int ret;
+
+	if (!hnae3_ae_dev_tm_flush_supported(hdev))
+		return 0;
+
+	hclge_cmd_setup_basic_desc(&desc, HCLGE_OPC_TM_FLUSH, false);
+
+	desc.data[0] = cpu_to_le32(enable ? HCLGE_TM_FLUSH_EN_MSK : 0);
+
+	ret = hclge_cmd_send(&hdev->hw, &desc, 1);
+	if (ret) {
+		dev_err(&hdev->pdev->dev,
+			"failed to config tm flush, ret = %d\n", ret);
+		return ret;
+	}
+
+	if (enable)
+		msleep(HCLGE_TM_FLUSH_TIME_MS);
+
+	return ret;
+}
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.h b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.h
index dd6f1fd486cf2..45dcfef3f90cc 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_tm.h
@@ -33,6 +33,9 @@ enum hclge_opcode_type;
 #define HCLGE_DSCP_MAP_TC_BD_NUM	2
 #define HCLGE_DSCP_TC_SHIFT(n)		(((n) & 1) * 4)
 
+#define HCLGE_TM_FLUSH_TIME_MS	10
+#define HCLGE_TM_FLUSH_EN_MSK	BIT(0)
+
 struct hclge_pg_to_pri_link_cmd {
 	u8 pg_id;
 	u8 rsvd1[3];
@@ -272,4 +275,5 @@ int hclge_tm_get_port_shaper(struct hclge_dev *hdev,
 			     struct hclge_tm_shaper_para *para);
 int hclge_up_to_tc_map(struct hclge_dev *hdev);
 int hclge_dscp_to_tc_map(struct hclge_dev *hdev);
+int hclge_tm_flush_cfg(struct hclge_dev *hdev, bool enable);
 #endif
-- 
2.40.1

[PATCH AUTOSEL 6.4 20/54] ethernet: atheros: fix return value check in atl1c_tso_csum()

[Sasha Levin]

From: Yuanjun Gong <ruc_gongyuanjun@163.com>

[ Upstream commit 8d01da0a1db237c44c92859ce3612df7af8d3a53 ]

in atl1c_tso_csum, it should check the return value of pskb_trim(),
and return an error code if an unexpected value is returned
by pskb_trim().

Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index 4a288799633f8..940c5d1ff9cfc 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -2094,8 +2094,11 @@ static int atl1c_tso_csum(struct atl1c_adapter *adapter,
 			real_len = (((unsigned char *)ip_hdr(skb) - skb->data)
 					+ ntohs(ip_hdr(skb)->tot_len));
 
-			if (real_len < skb->len)
-				pskb_trim(skb, real_len);
+			if (real_len < skb->len) {
+				err = pskb_trim(skb, real_len);
+				if (err)
+					return err;
+			}
 
 			hdr_len = skb_tcp_all_headers(skb);
 			if (unlikely(skb->len == hdr_len)) {
-- 
2.40.1

[PATCH AUTOSEL 6.4 21/54] vxlan: generalize vxlan_parse_gpe_hdr and remove unused args

[Sasha Levin]

From: Jiri Benc <jbenc@redhat.com>

[ Upstream commit 17a0a64448b568442a101de09575f81ffdc45d15 ]

The vxlan_parse_gpe_hdr function extracts the next protocol value from
the GPE header and marks GPE bits as parsed.

In order to be used in the next patch, split the function into protocol
extraction and bit marking. The bit marking is meaningful only in
vxlan_rcv; move it directly there.

Rename the function to vxlan_parse_gpe_proto to reflect what it now
does. Remove unused arguments skb and vxflags. Move the function earlier
in the file to allow it to be called from more places in the next patch.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/vxlan/vxlan_core.c | 58 ++++++++++++++++------------------
 1 file changed, 28 insertions(+), 30 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 561fe1b314f5f..3e3cdd4c18d43 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -623,6 +623,32 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
 	return 1;
 }
 
+static bool vxlan_parse_gpe_proto(struct vxlanhdr *hdr, __be16 *protocol)
+{
+	struct vxlanhdr_gpe *gpe = (struct vxlanhdr_gpe *)hdr;
+
+	/* Need to have Next Protocol set for interfaces in GPE mode. */
+	if (!gpe->np_applied)
+		return false;
+	/* "The initial version is 0. If a receiver does not support the
+	 * version indicated it MUST drop the packet.
+	 */
+	if (gpe->version != 0)
+		return false;
+	/* "When the O bit is set to 1, the packet is an OAM packet and OAM
+	 * processing MUST occur." However, we don't implement OAM
+	 * processing, thus drop the packet.
+	 */
+	if (gpe->oam_flag)
+		return false;
+
+	*protocol = tun_p_to_eth_p(gpe->next_protocol);
+	if (!*protocol)
+		return false;
+
+	return true;
+}
+
 static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
 					  unsigned int off,
 					  struct vxlanhdr *vh, size_t hdrlen,
@@ -1525,35 +1551,6 @@ static void vxlan_parse_gbp_hdr(struct vxlanhdr *unparsed,
 	unparsed->vx_flags &= ~VXLAN_GBP_USED_BITS;
 }
 
-static bool vxlan_parse_gpe_hdr(struct vxlanhdr *unparsed,
-				__be16 *protocol,
-				struct sk_buff *skb, u32 vxflags)
-{
-	struct vxlanhdr_gpe *gpe = (struct vxlanhdr_gpe *)unparsed;
-
-	/* Need to have Next Protocol set for interfaces in GPE mode. */
-	if (!gpe->np_applied)
-		return false;
-	/* "The initial version is 0. If a receiver does not support the
-	 * version indicated it MUST drop the packet.
-	 */
-	if (gpe->version != 0)
-		return false;
-	/* "When the O bit is set to 1, the packet is an OAM packet and OAM
-	 * processing MUST occur." However, we don't implement OAM
-	 * processing, thus drop the packet.
-	 */
-	if (gpe->oam_flag)
-		return false;
-
-	*protocol = tun_p_to_eth_p(gpe->next_protocol);
-	if (!*protocol)
-		return false;
-
-	unparsed->vx_flags &= ~VXLAN_GPE_USED_BITS;
-	return true;
-}
-
 static bool vxlan_set_mac(struct vxlan_dev *vxlan,
 			  struct vxlan_sock *vs,
 			  struct sk_buff *skb, __be32 vni)
@@ -1655,8 +1652,9 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	 * used by VXLAN extensions if explicitly requested.
 	 */
 	if (vs->flags & VXLAN_F_GPE) {
-		if (!vxlan_parse_gpe_hdr(&unparsed, &protocol, skb, vs->flags))
+		if (!vxlan_parse_gpe_proto(&unparsed, &protocol))
 			goto drop;
+		unparsed.vx_flags &= ~VXLAN_GPE_USED_BITS;
 		raw_proto = true;
 	}
 
-- 
2.40.1

[PATCH AUTOSEL 6.4 48/54] rbd: harden get_lock_owner_info() a bit

[Sasha Levin]

From: Ilya Dryomov <idryomov@gmail.com>

[ Upstream commit 8ff2c64c9765446c3cef804fb99da04916603e27 ]

- we want the exclusive lock type, so test for it directly
- use sscanf() to actually parse the lock cookie and avoid admitting
  invalid handles
- bail if locker has a blank address

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/block/rbd.c  | 21 +++++++++++++++------
 net/ceph/messenger.c |  1 +
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 7c37c047dbea2..a6210dfae0012 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3862,10 +3862,9 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
 	u32 num_lockers;
 	u8 lock_type;
 	char *lock_tag;
+	u64 handle;
 	int ret;
 
-	dout("%s rbd_dev %p\n", __func__, rbd_dev);
-
 	ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
 				 &rbd_dev->header_oloc, RBD_LOCK_NAME,
 				 &lock_type, &lock_tag, &lockers, &num_lockers);
@@ -3886,18 +3885,28 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
 		goto err_busy;
 	}
 
-	if (lock_type == CEPH_CLS_LOCK_SHARED) {
-		rbd_warn(rbd_dev, "shared lock type detected");
+	if (lock_type != CEPH_CLS_LOCK_EXCLUSIVE) {
+		rbd_warn(rbd_dev, "incompatible lock type detected");
 		goto err_busy;
 	}
 
 	WARN_ON(num_lockers != 1);
-	if (strncmp(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
-		    strlen(RBD_LOCK_COOKIE_PREFIX))) {
+	ret = sscanf(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu",
+		     &handle);
+	if (ret != 1) {
 		rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
 			 lockers[0].id.cookie);
 		goto err_busy;
 	}
+	if (ceph_addr_is_blank(&lockers[0].info.addr)) {
+		rbd_warn(rbd_dev, "locker has a blank address");
+		goto err_busy;
+	}
+
+	dout("%s rbd_dev %p got locker %s%llu@%pISpc/%u handle %llu\n",
+	     __func__, rbd_dev, ENTITY_NAME(lockers[0].id.name),
+	     &lockers[0].info.addr.in_addr,
+	     le32_to_cpu(lockers[0].info.addr.nonce), handle);
 
 out:
 	kfree(lock_tag);
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index cd7b0bf5369ec..5eb4898cccd4c 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1123,6 +1123,7 @@ bool ceph_addr_is_blank(const struct ceph_entity_addr *addr)
 		return true;
 	}
 }
+EXPORT_SYMBOL(ceph_addr_is_blank);
 
 int ceph_addr_port(const struct ceph_entity_addr *addr)
 {
-- 
2.40.1