[PATCH v2 00/12] IB/srp patches for kernel v4.2

[PATCH v2 00/12] IB/srp patches for kernel v4.2

[Bart Van Assche]

Hello Doug,

My own testing and code review of the SRP initiator driver during the 
past months resulted in a series of twelve patches with bug fixes, 
source code simplifications and other improvements. Patches 1..6 are bug 
fixes and have been tagged for the stable kernel series. These patches 
have been tested against kernel v4.1-rc3. Please consider these patches 
for the v4.2 merge window.

The changes compared to the previous version of this series are as follows:
- Dropped the target->connected state.
- Dropped patch "IB/srp: Make CM timeout dependent on subnet timeout".
- Moved a change from patch "IB/srp: Fix reconnection failure handling"
   into patch "IB/srp: Remove !ch->target tests from the reconnect code".

The individual patches in this series are:
0001-scsi_transport_srp-Introduce-srp_wait_for_queuecomma.patch
0002-scsi_transport_srp-Fix-a-race-condition.patch
0003-IB-srp-Remove-an-extraneous-scsi_host_put-from-an-er.patch
0004-IB-srp-Fix-a-connection-setup-race.patch
0005-IB-srp-Fix-connection-state-tracking.patch
0006-IB-srp-Fix-reconnection-failure-handling.patch
0007-scsi_transport_srp-Reduce-failover-time.patch
0008-IB-srp-Remove-superfluous-casts.patch
0009-IB-srp-Rearrange-module-description.patch
0010-IB-srp-Remove-a-superfluous-check-from-srp_free_req_.patch
0011-IB-srp-Remove-ch-target-tests-from-the-reconnect-cod.patch
0012-IB-srp-Add-64-bit-LUN-support.patch

Thanks,

Bart.
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[PATCH v2 01/12] scsi_transport_srp: Introduce srp_wait_for_queuecommand()

[Bart Van Assche]

Introduce the helper function srp_wait_for_queuecommand().
Move the definition of scsi_request_fn_active(). Add a comment
above srp_wait_for_queuecommand() that support for scsi-mq needs
to be added.

This patch does not change any functionality. A second call to
srp_wait_for_queuecommand() will be introduced in the next patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.13
---
 drivers/scsi/scsi_transport_srp.c | 54 ++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index ae45bd9..e05cd7e 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -396,6 +396,36 @@ static void srp_reconnect_work(struct work_struct *work)
 	}
 }
 
+/**
+ * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
+ * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
+ *
+ * To do: add support for scsi-mq in this function.
+ */
+static int scsi_request_fn_active(struct Scsi_Host *shost)
+{
+	struct scsi_device *sdev;
+	struct request_queue *q;
+	int request_fn_active = 0;
+
+	shost_for_each_device(sdev, shost) {
+		q = sdev->request_queue;
+
+		spin_lock_irq(q->queue_lock);
+		request_fn_active += q->request_fn_active;
+		spin_unlock_irq(q->queue_lock);
+	}
+
+	return request_fn_active;
+}
+
+/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */
+static void srp_wait_for_queuecommand(struct Scsi_Host *shost)
+{
+	while (scsi_request_fn_active(shost))
+		msleep(20);
+}
+
 static void __rport_fail_io_fast(struct srp_rport *rport)
 {
 	struct Scsi_Host *shost = rport_to_shost(rport);
@@ -504,27 +534,6 @@ void srp_start_tl_fail_timers(struct srp_rport *rport)
 EXPORT_SYMBOL(srp_start_tl_fail_timers);
 
 /**
- * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
- * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
- */
-static int scsi_request_fn_active(struct Scsi_Host *shost)
-{
-	struct scsi_device *sdev;
-	struct request_queue *q;
-	int request_fn_active = 0;
-
-	shost_for_each_device(sdev, shost) {
-		q = sdev->request_queue;
-
-		spin_lock_irq(q->queue_lock);
-		request_fn_active += q->request_fn_active;
-		spin_unlock_irq(q->queue_lock);
-	}
-
-	return request_fn_active;
-}
-
-/**
  * srp_reconnect_rport() - reconnect to an SRP target port
  * @rport: SRP target port.
  *
@@ -559,8 +568,7 @@ int srp_reconnect_rport(struct srp_rport *rport)
 	if (res)
 		goto out;
 	scsi_target_block(&shost->shost_gendev);
-	while (scsi_request_fn_active(shost))
-		msleep(20);
+	srp_wait_for_queuecommand(shost);
 	res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
 	pr_debug("%s (state %d): transport.reconnect() returned %d\n",
 		 dev_name(&shost->shost_gendev), rport->state, res);
-- 
2.1.4

[PATCH v2 02/12] scsi_transport_srp: Fix a race condition

[Bart Van Assche]

Avoid that srp_terminate_io() can get invoked while srp_queuecommand()
is in progress. This patch avoids that an I/O timeout can trigger the
following kernel warning:

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:1447 srp_terminate_io+0xef/0x100 [ib_srp]()
Call Trace:
 [<ffffffff814c65a2>] dump_stack+0x4e/0x68
 [<ffffffff81051f71>] warn_slowpath_common+0x81/0xa0
 [<ffffffff8105204a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa075f51f>] srp_terminate_io+0xef/0x100 [ib_srp]
 [<ffffffffa07495da>] __rport_fail_io_fast+0xba/0xc0 [scsi_transport_srp]
 [<ffffffffa0749a90>] rport_fast_io_fail_timedout+0xe0/0xf0 [scsi_transport_srp]
 [<ffffffff8106e09b>] process_one_work+0x1db/0x780
 [<ffffffff8106e75b>] worker_thread+0x11b/0x450
 [<ffffffff81073c64>] kthread+0xe4/0x100
 [<ffffffff814cf26c>] ret_from_fork+0x7c/0xb0

See also patch "scsi_transport_srp: Add transport layer error
handling" (commit ID 29c17324803c).

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: James Bottomley <JBottomley-O3H1v1f1dlM@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org> #v3.13
---
 drivers/scsi/scsi_transport_srp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index e05cd7e..f115f67 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -439,8 +439,10 @@ static void __rport_fail_io_fast(struct srp_rport *rport)
 
 	/* Involve the LLD if possible to terminate all I/O on the rport. */
 	i = to_srp_internal(shost->transportt);
-	if (i->f->terminate_rport_io)
+	if (i->f->terminate_rport_io) {
+		srp_wait_for_queuecommand(shost);
 		i->f->terminate_rport_io(rport);
+	}
 }
 
 /**
-- 
2.1.4

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[PATCH v2 03/12] IB/srp: Remove an extraneous scsi_host_put() from an error path

[Bart Van Assche]

Fix a scsi_get_host() / scsi_host_put() imbalance in the error
path of srp_create_target(). See also patch "IB/srp: Avoid that
I/O hangs due to a cable pull during LUN scanning" (commit ID
34aa654ecb8e).

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Reviewed-by: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org> #v3.19
---
 drivers/infiniband/ulp/srp/ib_srp.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 4ee91aa..cdb7a71 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -3188,11 +3188,11 @@ static ssize_t srp_create_target(struct device *dev,
 
 	ret = srp_parse_options(buf, target);
 	if (ret)
-		goto err;
+		goto out;
 
 	ret = scsi_init_shared_tag_map(target_host, target_host->can_queue);
 	if (ret)
-		goto err;
+		goto out;
 
 	target->req_ring_size = target->queue_size - SRP_TSK_MGMT_SQ_SIZE;
 
@@ -3203,7 +3203,7 @@ static ssize_t srp_create_target(struct device *dev,
 			     be64_to_cpu(target->ioc_guid),
 			     be64_to_cpu(target->initiator_ext));
 		ret = -EEXIST;
-		goto err;
+		goto out;
 	}
 
 	if (!srp_dev->has_fmr && !srp_dev->has_fr && !target->allow_ext_sg &&
@@ -3224,7 +3224,7 @@ static ssize_t srp_create_target(struct device *dev,
 	spin_lock_init(&target->lock);
 	ret = ib_query_gid(ibdev, host->port, 0, &target->sgid);
 	if (ret)
-		goto err;
+		goto out;
 
 	ret = -ENOMEM;
 	target->ch_count = max_t(unsigned, num_online_nodes(),
@@ -3235,7 +3235,7 @@ static ssize_t srp_create_target(struct device *dev,
 	target->ch = kcalloc(target->ch_count, sizeof(*target->ch),
 			     GFP_KERNEL);
 	if (!target->ch)
-		goto err;
+		goto out;
 
 	node_idx = 0;
 	for_each_online_node(node) {
@@ -3331,9 +3331,6 @@ err_disconnect:
 	}
 
 	kfree(target->ch);
-
-err:
-	scsi_host_put(target_host);
 	goto out;
 }
 
-- 
2.1.4

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[PATCH v2 04/12] IB/srp: Fix a connection setup race

[Bart Van Assche]

Avoid that receiving a DREQ while RDMA channels are being
established causes target->qp_in_error to be reset.

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org> #v3.19
---
 drivers/infiniband/ulp/srp/ib_srp.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index cdb7a71..034d755 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1009,8 +1009,6 @@ static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
 
 	WARN_ON_ONCE(!multich && target->connected);
 
-	target->qp_in_error = false;
-
 	ret = srp_lookup_path(ch);
 	if (ret)
 		return ret;
@@ -1259,6 +1257,9 @@ static int srp_rport_reconnect(struct srp_rport *rport)
 		for (j = 0; j < target->queue_size; ++j)
 			list_add(&ch->tx_ring[j]->list, &ch->free_tx);
 	}
+
+	target->qp_in_error = false;
+
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
 		if (ret || !ch->target) {
-- 
2.1.4

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[PATCH v2 05/12] IB/srp: Fix connection state tracking

[Bart Van Assche]

Reception of a DREQ message only causes the state of a single
channel to change. Hence move the 'connected' member variable
from the target to the channel data structure. This patch
avoids that following false positive warning can be reported
by srp_destroy_qp():

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:617 srp_destroy_qp+0xa6/0x120 [ib_srp]()
Call Trace:
[<ffffffff8106e10f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8106e16a>] warn_slowpath_null+0x1a/0x20
[<ffffffffa0440226>] srp_destroy_qp+0xa6/0x120 [ib_srp]
[<ffffffffa0440322>] srp_free_ch_ib+0x82/0x1e0 [ib_srp]
[<ffffffffa044408b>] srp_create_target+0x7ab/0x998 [ib_srp]
[<ffffffff81346f60>] dev_attr_store+0x20/0x30
[<ffffffff811dd90f>] sysfs_write_file+0xef/0x170
[<ffffffff8116d248>] vfs_write+0xc8/0x190
[<ffffffff8116d411>] sys_write+0x51/0x90

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org> #v3.19
---
 drivers/infiniband/ulp/srp/ib_srp.c | 60 ++++++++++++++++++-------------------
 drivers/infiniband/ulp/srp/ib_srp.h |  2 +-
 2 files changed, 30 insertions(+), 32 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 034d755..83e4d8a 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -465,14 +465,13 @@ static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
  */
 static void srp_destroy_qp(struct srp_rdma_ch *ch)
 {
-	struct srp_target_port *target = ch->target;
 	static struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
 	static struct ib_recv_wr wr = { .wr_id = SRP_LAST_WR_ID };
 	struct ib_recv_wr *bad_wr;
 	int ret;
 
 	/* Destroying a QP and reusing ch->done is only safe if not connected */
-	WARN_ON_ONCE(target->connected);
+	WARN_ON_ONCE(ch->connected);
 
 	ret = ib_modify_qp(ch->qp, &attr, IB_QP_STATE);
 	WARN_ONCE(ret, "ib_cm_init_qp_attr() returned %d\n", ret);
@@ -827,35 +826,19 @@ static bool srp_queue_remove_work(struct srp_target_port *target)
 	return changed;
 }
 
-static bool srp_change_conn_state(struct srp_target_port *target,
-				  bool connected)
-{
-	bool changed = false;
-
-	spin_lock_irq(&target->lock);
-	if (target->connected != connected) {
-		target->connected = connected;
-		changed = true;
-	}
-	spin_unlock_irq(&target->lock);
-
-	return changed;
-}
-
 static void srp_disconnect_target(struct srp_target_port *target)
 {
 	struct srp_rdma_ch *ch;
 	int i;
 
-	if (srp_change_conn_state(target, false)) {
-		/* XXX should send SRP_I_LOGOUT request */
+	/* XXX should send SRP_I_LOGOUT request */
 
-		for (i = 0; i < target->ch_count; i++) {
-			ch = &target->ch[i];
-			if (ch->cm_id && ib_send_cm_dreq(ch->cm_id, NULL, 0)) {
-				shost_printk(KERN_DEBUG, target->scsi_host,
-					     PFX "Sending CM DREQ failed\n");
-			}
+	for (i = 0; i < target->ch_count; i++) {
+		ch = &target->ch[i];
+		ch->connected = false;
+		if (ch->cm_id && ib_send_cm_dreq(ch->cm_id, NULL, 0)) {
+			shost_printk(KERN_DEBUG, target->scsi_host,
+				     PFX "Sending CM DREQ failed\n");
 		}
 	}
 }
@@ -1002,12 +985,26 @@ static void srp_rport_delete(struct srp_rport *rport)
 	srp_queue_remove_work(target);
 }
 
+/**
+ * srp_connected_ch() - number of connected channels
+ * @target: SRP target port.
+ */
+static int srp_connected_ch(struct srp_target_port *target)
+{
+	int i, c = 0;
+
+	for (i = 0; i < target->ch_count; i++)
+		c += target->ch[i].connected;
+
+	return c;
+}
+
 static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
 {
 	struct srp_target_port *target = ch->target;
 	int ret;
 
-	WARN_ON_ONCE(!multich && target->connected);
+	WARN_ON_ONCE(!multich && srp_connected_ch(target) > 0);
 
 	ret = srp_lookup_path(ch);
 	if (ret)
@@ -1030,7 +1027,7 @@ static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
 		 */
 		switch (ch->status) {
 		case 0:
-			srp_change_conn_state(target, true);
+			ch->connected = true;
 			return 0;
 
 		case SRP_PORT_REDIRECT:
@@ -1946,7 +1943,7 @@ static void srp_handle_qp_err(u64 wr_id, enum ib_wc_status wc_status,
 		return;
 	}
 
-	if (target->connected && !target->qp_in_error) {
+	if (ch->connected && !target->qp_in_error) {
 		if (wr_id & LOCAL_INV_WR_ID_MASK) {
 			shost_printk(KERN_ERR, target->scsi_host, PFX
 				     "LOCAL_INV failed with status %d\n",
@@ -2384,7 +2381,7 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
 	case IB_CM_DREQ_RECEIVED:
 		shost_printk(KERN_WARNING, target->scsi_host,
 			     PFX "DREQ received - connection closed\n");
-		srp_change_conn_state(target, false);
+		ch->connected = false;
 		if (ib_send_cm_drep(cm_id, NULL, 0))
 			shost_printk(KERN_ERR, target->scsi_host,
 				     PFX "Sending CM DREP failed\n");
@@ -2440,7 +2437,7 @@ static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag,
 	struct srp_iu *iu;
 	struct srp_tsk_mgmt *tsk_mgmt;
 
-	if (!target->connected || target->qp_in_error)
+	if (!ch->connected || target->qp_in_error)
 		return -1;
 
 	init_completion(&ch->tsk_mgmt_done);
@@ -2814,7 +2811,8 @@ static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
 	scsi_scan_target(&target->scsi_host->shost_gendev,
 			 0, target->scsi_id, SCAN_WILD_CARD, 0);
 
-	if (!target->connected || target->qp_in_error) {
+	if (srp_connected_ch(target) < target->ch_count ||
+	    target->qp_in_error) {
 		shost_printk(KERN_INFO, target->scsi_host,
 			     PFX "SCSI scan failed - removing SCSI host\n");
 		srp_queue_remove_work(target);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index a611556..e690847 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -170,6 +170,7 @@ struct srp_rdma_ch {
 
 	struct completion	tsk_mgmt_done;
 	u8			tsk_mgmt_status;
+	bool			connected;
 };
 
 /**
@@ -214,7 +215,6 @@ struct srp_target_port {
 	__be16			pkey;
 
 	u32			rq_tmo_jiffies;
-	bool			connected;
 
 	int			zero_req_lim;
 
-- 
2.1.4

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[PATCH v2 06/12] IB/srp: Fix reconnection failure handling

[Bart Van Assche]

Although it is possible to let SRP I/O continue if a reconnect
results in a reduction of the number of channels, the current
code does not handle this scenario correctly. Instead of making
the reconnect code more complex, consider this as a reconnection
failure.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
---
 drivers/infiniband/ulp/srp/ib_srp.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 83e4d8a..982e329 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1259,11 +1259,8 @@ static int srp_rport_reconnect(struct srp_rport *rport)
 
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
-		if (ret || !ch->target) {
-			if (i > 1)
-				ret = 0;
+		if (ret || !ch->target)
 			break;
-		}
 		ret = srp_connect_ch(ch, multich);
 		multich = true;
 	}
-- 
2.1.4

[PATCH v2 07/12] scsi_transport_srp: Reduce failover time

[Bart Van Assche]

Unlike FC, there is no risk that SCSI devices will be offlined
by the SCSI error handler if the SCSI error handler is started
while a reconnect attempt is ongoing. Hence report timeout errors
as soon as possible if a higher software layer (e.g. multipathd)
needs to be informed about a timeout. It is assumed that if both
fast_io_fail_tmo < 0 and rport->dev_loss_tmo < 0 that this means
that there is no need to report timeouts quickly.

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: James Bottomley <JBottomley-O3H1v1f1dlM@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
---
 drivers/scsi/scsi_transport_srp.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index f115f67..a85292b 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -61,6 +61,11 @@ static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
 	return dev_to_shost(r->dev.parent);
 }
 
+static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
+{
+	return transport_class_to_srp_rport(&shost->shost_gendev);
+}
+
 /**
  * srp_tmo_valid() - check timeout combination validity
  * @reconnect_delay: Reconnect delay in seconds.
@@ -628,9 +633,11 @@ static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
 	struct scsi_device *sdev = scmd->device;
 	struct Scsi_Host *shost = sdev->host;
 	struct srp_internal *i = to_srp_internal(shost->transportt);
+	struct srp_rport *rport = shost_to_rport(shost);
 
 	pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
-	return i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
+	return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 &&
+		i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
 		BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
 }
 
-- 
2.1.4

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[PATCH v2 08/12] IB/srp: Remove superfluous casts

[Bart Van Assche]

A long time ago the data type int64_t was declared as long long
on x86 systems and as long on PPC systems. Today that data type
is declared as long long on all Linux architectures. This means
that the casts from uint64_t into unsigned long long are
superfluous. Remove these superfluous casts.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 982e329..6025fb8 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -796,7 +796,7 @@ static int srp_send_req(struct srp_rdma_ch *ch, bool multich)
 		shost_printk(KERN_DEBUG, target->scsi_host,
 			     PFX "Topspin/Cisco initiator port ID workaround "
 			     "activated for target GUID %016llx\n",
-			     (unsigned long long) be64_to_cpu(target->ioc_guid));
+			     be64_to_cpu(target->ioc_guid));
 		memset(req->priv.initiator_port_id, 0, 8);
 		memcpy(req->priv.initiator_port_id + 8,
 		       &target->srp_host->srp_dev->dev->node_guid, 8);
@@ -2574,8 +2574,7 @@ static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
 {
 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
 
-	return sprintf(buf, "0x%016llx\n",
-		       (unsigned long long) be64_to_cpu(target->id_ext));
+	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->id_ext));
 }
 
 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
@@ -2583,8 +2582,7 @@ static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
 {
 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
 
-	return sprintf(buf, "0x%016llx\n",
-		       (unsigned long long) be64_to_cpu(target->ioc_guid));
+	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->ioc_guid));
 }
 
 static ssize_t show_service_id(struct device *dev,
@@ -2592,8 +2590,7 @@ static ssize_t show_service_id(struct device *dev,
 {
 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
 
-	return sprintf(buf, "0x%016llx\n",
-		       (unsigned long long) be64_to_cpu(target->service_id));
+	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->service_id));
 }
 
 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
@@ -2784,7 +2781,7 @@ static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
 
 	target->state = SRP_TARGET_SCANNING;
 	sprintf(target->target_name, "SRP.T10:%016llX",
-		 (unsigned long long) be64_to_cpu(target->id_ext));
+		be64_to_cpu(target->id_ext));
 
 	if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
 		return -ENODEV;
-- 
2.1.4

[PATCH v2 09/12] IB/srp: Rearrange module description

[Bart Van Assche]

Move the module version and release date into separate fields.
This makes the modinfo output easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Reviewed-by: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 6025fb8..24b9d22 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -59,9 +59,10 @@
 #define DRV_RELDATE	"July 1, 2013"
 
 MODULE_AUTHOR("Roland Dreier");
-MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
-		   "v" DRV_VERSION " (" DRV_RELDATE ")");
+MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator");
 MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRV_VERSION);
+MODULE_INFO(release_date, DRV_RELDATE);
 
 static unsigned int srp_sg_tablesize;
 static unsigned int cmd_sg_entries;
-- 
2.1.4

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[PATCH v2 10/12] IB/srp: Remove a superfluous check from srp_free_req_data()

[Bart Van Assche]

The function srp_free_req_data() does not use ch->target.
Hence remove the ch->target != NULL check.

Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 24b9d22..dd6f928 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -852,7 +852,7 @@ static void srp_free_req_data(struct srp_target_port *target,
 	struct srp_request *req;
 	int i;
 
-	if (!ch->target || !ch->req_ring)
+	if (!ch->req_ring)
 		return;
 
 	for (i = 0; i < target->req_ring_size; ++i) {
-- 
2.1.4

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[PATCH v2 11/12] IB/srp: Remove !ch->target tests from the reconnect code

[Bart Van Assche]

Remove the !ch->target tests from the reconnect code. These
tests are not needed: upon entry of srp_rport_reconnect()
it is guaranteed that all ch->target pointers are non-NULL.
None of the functions srp_new_cm_id(), srp_finish_req(),
srp_create_ch_ib() nor srp_connect_ch() modifies this pointer.
srp_free_ch_ib() is never called concurrently with
srp_rport_reconnect().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index dd6f928..a0a2348 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1226,14 +1226,10 @@ static int srp_rport_reconnect(struct srp_rport *rport)
 	 */
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
-		if (!ch->target)
-			break;
 		ret += srp_new_cm_id(ch);
 	}
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
-		if (!ch->target)
-			break;
 		for (j = 0; j < target->req_ring_size; ++j) {
 			struct srp_request *req = &ch->req_ring[j];
 
@@ -1242,8 +1238,6 @@ static int srp_rport_reconnect(struct srp_rport *rport)
 	}
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
-		if (!ch->target)
-			break;
 		/*
 		 * Whether or not creating a new CM ID succeeded, create a new
 		 * QP. This guarantees that all completion callback function
@@ -1260,7 +1254,7 @@ static int srp_rport_reconnect(struct srp_rport *rport)
 
 	for (i = 0; i < target->ch_count; i++) {
 		ch = &target->ch[i];
-		if (ret || !ch->target)
+		if (ret)
 			break;
 		ret = srp_connect_ch(ch, multich);
 		multich = true;
-- 
2.1.4

[PATCH v2 12/12] IB/srp: Add 64-bit LUN support

[Bart Van Assche]

The SCSI standard defines 64-bit values for LUNs. Large arrays
employing large or hierarchical LUN numbers become more and more
common. So update the SRP initiator to use 64-bit LUN numbers.
See also Hannes Reinecke, commit 9cb78c16f5da ("scsi: use 64-bit LUNs"),
June 2014.

The largest LUN number that has been tested is 0xd2003fff00000000.

Checked the following structure sizes with gdb:
* sizeof(struct srp_cmd) = 48
* sizeof(struct srp_tsk_mgmt) = 48
* sizeof(struct srp_aer_req) = 36

The ibmvscsi changes have been compile tested only (on a PPC system).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 12 ++++++------
 drivers/infiniband/ulp/srp/ib_srp.h |  1 -
 drivers/scsi/ibmvscsi/ibmvscsi.c    |  6 +++---
 include/scsi/srp.h                  |  7 ++++---
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index a0a2348..6b6f6e3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1848,7 +1848,7 @@ static void srp_process_aer_req(struct srp_rdma_ch *ch,
 	s32 delta = be32_to_cpu(req->req_lim_delta);
 
 	shost_printk(KERN_ERR, target->scsi_host, PFX
-		     "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
+		     "ignoring AER for LUN %llu\n", scsilun_to_int(&req->lun));
 
 	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
 		shost_printk(KERN_ERR, target->scsi_host, PFX
@@ -2040,7 +2040,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 	memset(cmd, 0, sizeof *cmd);
 
 	cmd->opcode = SRP_CMD;
-	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
+	int_to_scsilun(scmnd->device->lun, &cmd->lun);
 	cmd->tag    = tag;
 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
 
@@ -2420,8 +2420,8 @@ srp_change_queue_depth(struct scsi_device *sdev, int qdepth)
 	return scsi_change_queue_depth(sdev, qdepth);
 }
 
-static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag,
-			     unsigned int lun, u8 func)
+static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag, u64 lun,
+			     u8 func)
 {
 	struct srp_target_port *target = ch->target;
 	struct srp_rport *rport = target->rport;
@@ -2455,7 +2455,7 @@ static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag,
 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
 
 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
-	tsk_mgmt->lun		= cpu_to_be64((u64) lun << 48);
+	int_to_scsilun(lun, &tsk_mgmt->lun);
 	tsk_mgmt->tag		= req_tag | SRP_TAG_TSK_MGMT;
 	tsk_mgmt->tsk_mgmt_func = func;
 	tsk_mgmt->task_tag	= req_tag;
@@ -3150,7 +3150,7 @@ static ssize_t srp_create_target(struct device *dev,
 	target_host->transportt  = ib_srp_transport_template;
 	target_host->max_channel = 0;
 	target_host->max_id      = 1;
-	target_host->max_lun     = SRP_MAX_LUN;
+	target_host->max_lun     = -1LL;
 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
 
 	target = host_to_target(target_host);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index e690847..17ee3f8 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -54,7 +54,6 @@ enum {
 	SRP_DLID_REDIRECT	= 2,
 	SRP_STALE_CONN		= 3,
 
-	SRP_MAX_LUN		= 512,
 	SRP_DEF_SG_TABLESIZE	= 12,
 
 	SRP_DEFAULT_QUEUE_SIZE	= 1 << 6,
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index acea5d6..6a41c36 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1053,7 +1053,7 @@ static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd,
 	memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
 	srp_cmd->opcode = SRP_CMD;
 	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb));
-	srp_cmd->lun = cpu_to_be64(((u64)lun) << 48);
+	int_to_scsilun(lun, &srp_cmd->lun);
 
 	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
 		if (!firmware_has_feature(FW_FEATURE_CMO))
@@ -1529,7 +1529,7 @@ static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
 		/* Set up an abort SRP command */
 		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
 		tsk_mgmt->opcode = SRP_TSK_MGMT;
-		tsk_mgmt->lun = cpu_to_be64(((u64) lun) << 48);
+		int_to_scsilun(lun, &tsk_mgmt->lun);
 		tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
 		tsk_mgmt->task_tag = (u64) found_evt;
 
@@ -1652,7 +1652,7 @@ static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
 		/* Set up a lun reset SRP command */
 		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
 		tsk_mgmt->opcode = SRP_TSK_MGMT;
-		tsk_mgmt->lun = cpu_to_be64(((u64) lun) << 48);
+		int_to_scsilun(lun, &tsk_mgmt->lun);
 		tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
 
 		evt->sync_srp = &srp_rsp;
diff --git a/include/scsi/srp.h b/include/scsi/srp.h
index 1ae84db..5be834d 100644
--- a/include/scsi/srp.h
+++ b/include/scsi/srp.h
@@ -42,6 +42,7 @@
  */
 
 #include <linux/types.h>
+#include <scsi/scsi.h>
 
 enum {
 	SRP_LOGIN_REQ	= 0x00,
@@ -179,7 +180,7 @@ struct srp_tsk_mgmt {
 	u8	reserved1[6];
 	u64	tag;
 	u8	reserved2[4];
-	__be64	lun __attribute__((packed));
+	struct scsi_lun	lun;
 	u8	reserved3[2];
 	u8	tsk_mgmt_func;
 	u8	reserved4;
@@ -200,7 +201,7 @@ struct srp_cmd {
 	u8	data_in_desc_cnt;
 	u64	tag;
 	u8	reserved2[4];
-	__be64	lun __attribute__((packed));
+	struct scsi_lun	lun;
 	u8	reserved3;
 	u8	task_attr;
 	u8	reserved4;
@@ -265,7 +266,7 @@ struct srp_aer_req {
 	__be32	req_lim_delta;
 	u64	tag;
 	u32	reserved2;
-	__be64	lun;
+	struct scsi_lun	lun;
 	__be32	sense_data_len;
 	u32	reserved3;
 	u8	sense_data[0];
-- 
2.1.4