[linux-rdma][PATCH 3/6] SRP implement device_loss_timeout per target

[Vu Pham]

Introducing device_loss_timeout per target granuality.
SRP driver will propagate I/O errors and clean up connection resources after
device_loss_timeout expired when local port or target port disconnected from
the fabric.
   
Signed-off-by: Vu Pham <v...@mellanox.com>

 drivers/infiniband/ulp/srp/ib_srp.c |   12 +++++++++++-
 drivers/infiniband/ulp/srp/ib_srp.h |    1 +
 2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c 
b/drivers/infiniband/ulp/srp/ib_srp.c
index e44939a..047d488 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1298,7 +1298,6 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct 
ib_cm_event *event)
        case IB_CM_TIMEWAIT_EXIT:
                shost_printk(KERN_ERR, target->scsi_host,
                             PFX "connection closed\n");
-
                target->status = 0;
                break;
 
@@ -1657,6 +1656,7 @@ enum {
        SRP_OPT_MAX_CMD_PER_LUN = 1 << 6,
        SRP_OPT_IO_CLASS        = 1 << 7,
        SRP_OPT_INITIATOR_EXT   = 1 << 8,
+       SRP_OPT_DEVICE_LOSS_TMO = 1 << 9,
        SRP_OPT_ALL             = (SRP_OPT_ID_EXT       |
                                   SRP_OPT_IOC_GUID     |
                                   SRP_OPT_DGID         |
@@ -1674,6 +1674,7 @@ static const match_table_t srp_opt_tokens = {
        { SRP_OPT_MAX_CMD_PER_LUN,      "max_cmd_per_lun=%d"    },
        { SRP_OPT_IO_CLASS,             "io_class=%x"           },
        { SRP_OPT_INITIATOR_EXT,        "initiator_ext=%s"      },
+       { SRP_OPT_DEVICE_LOSS_TMO,      "device_loss_timeout=%d"},
        { SRP_OPT_ERR,                  NULL                    }
 };
 
@@ -1801,6 +1802,15 @@ static int srp_parse_options(const char *buf, struct 
srp_target_port *target)
                        kfree(p);
                        break;
 
+               case SRP_OPT_DEVICE_LOSS_TMO:
+                       if (match_int(args, &token)) {
+                               printk(KERN_WARNING PFX "bad device loss 
timeout '%s'\n", p);
+                               goto out;
+                       }
+                       if (token > 0)
+                               target->device_loss_timeout = token;
+                       break;
+
                default:
                        printk(KERN_WARNING PFX "unknown parameter or missing 
value "
                               "'%s' in target creation request\n", p);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h 
b/drivers/infiniband/ulp/srp/ib_srp.h
index e185b90..92db025 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -159,6 +159,7 @@ struct srp_target_port {
        int                     status;
        enum srp_target_state   state;
        int                     qp_in_error;
+       int                     device_loss_timeout;
 };
 
 struct srp_iu {