The current strategy in ib_srp for posting receive buffers is as follows:
* Post one buffer after channel establishment.
* Post one buffer before sending an SRP_CMD or SRP_TSK_MGMT to the target.
As a result, only the first non-SRP_RSP information unit from the target will
be processed. If that first information unit is an SRP_T_LOGOUT, it will be
processed. On the other hand, if the initiator receives an SRP_CRED_REQ or
SRP_AER_REQ before it receives a SRP_T_LOGOUT, the SRP_T_LOGOUT won't be
processed. This patch fixes this inconsistency by changing the strategy for
posting receive buffers as follows:
* Post all receive buffers after channel establishment.
* After a receive buffer has been consumed and processed, post it again.
A side effect is that the ib_post_recv() call is moved out of the SCSI command
processing path.
Signed-off-by: Bart Van Assche <bart.vanass...@gmail.com>
Cc: Roland Dreier <rola...@cisco.com>
Cc: David Dillow <d...@thedillows.org>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
b/drivers/infiniband/ulp/srp/ib_srp.c
index ed3f9eb..b9a38c2 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -82,6 +82,7 @@ static void srp_add_one(struct ib_device *device);
static void srp_remove_one(struct ib_device *device);
static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
+static int srp_post_recv(struct srp_target_port *target);
static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
static struct scsi_transport_template *ib_srp_transport_template;
@@ -868,6 +869,7 @@ static void srp_handle_recv(struct srp_target_port *target,
struct ib_wc *wc)
{
struct ib_device *dev;
struct srp_iu *iu;
+ int res;
u8 opcode;
iu = target->rx_ring[wc->wr_id];
@@ -915,6 +917,11 @@ static void srp_handle_recv(struct srp_target_port
*target, struct ib_wc *wc)
ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
DMA_FROM_DEVICE);
+
+ res = srp_post_recv(target);
+ if (res != 0)
+ shost_printk(KERN_ERR, target->scsi_host,
+ PFX "Recv failed with error code %d\n", res);
}
static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
@@ -1102,11 +1109,6 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
goto err;
}
- if (__srp_post_recv(target)) {
- shost_printk(KERN_ERR, target->scsi_host, PFX "Recv failed\n");
- goto err_unmap;
- }
-
ib_dma_sync_single_for_device(dev, iu->dma, srp_max_iu_len,
DMA_TO_DEVICE);
@@ -1249,6 +1251,7 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct
ib_cm_event *event)
int attr_mask = 0;
int comp = 0;
int opcode = 0;
+ int i;
switch (event->event) {
case IB_CM_REQ_ERROR:
@@ -1298,7 +1301,11 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct
ib_cm_event *event)
if (target->status)
break;
- target->status = srp_post_recv(target);
+ for (i = 0; i < SRP_RQ_SIZE; i++) {
+ target->status = srp_post_recv(target);
+ if (target->status)
+ break;
+ }
if (target->status)
break;
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
