[S390] dasd: revert LCU optimization

Remove the optimization that validate server is only called once per
LCU. If a device is set online we only know that we already know the
LCU. But if the pathgroup was lost in between we have to do a
validate server again to activate some features.
Since we have no indication when a pathgroup gets lost we have to do
a validate server every time a device is set online.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 553b3c5..b3beed5 100644 (file)
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -189,14 +189,12 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
        unsigned long flags;
        struct alias_server *server, *newserver;
        struct alias_lcu *lcu, *newlcu;
-       int is_lcu_known;
        struct dasd_uid uid;
 
        private = (struct dasd_eckd_private *) device->private;
 
        device->discipline->get_uid(device, &uid);
        spin_lock_irqsave(&aliastree.lock, flags);
-       is_lcu_known = 1;
        server = _find_server(&uid);
        if (!server) {
                spin_unlock_irqrestore(&aliastree.lock, flags);
@@ -208,7 +206,6 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
                if (!server) {
                        list_add(&newserver->server, &aliastree.serverlist);
                        server = newserver;
-                       is_lcu_known = 0;
                } else {
                        /* someone was faster */
                        _free_server(newserver);
@@ -226,12 +223,10 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
                if (!lcu) {
                        list_add(&newlcu->lcu, &server->lculist);
                        lcu = newlcu;
-                       is_lcu_known = 0;
                } else {
                        /* someone was faster */
                        _free_lcu(newlcu);
                }
-               is_lcu_known = 0;
        }
        spin_lock(&lcu->lock);
        list_add(&device->alias_list, &lcu->inactive_devices);
@@ -239,64 +234,7 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
        spin_unlock(&lcu->lock);
        spin_unlock_irqrestore(&aliastree.lock, flags);
 
-       return is_lcu_known;
-}
-
-/*
- * The first device to be registered on an LCU will have to do
- * some additional setup steps to configure that LCU on the
- * storage server. All further devices should wait with their
- * initialization until the first device is done.
- * To synchronize this work, the first device will call
- * dasd_alias_lcu_setup_complete when it is done, and all
- * other devices will wait for it with dasd_alias_wait_for_lcu_setup.
- */
-void dasd_alias_lcu_setup_complete(struct dasd_device *device)
-{
-       unsigned long flags;
-       struct alias_server *server;
-       struct alias_lcu *lcu;
-       struct dasd_uid uid;
-
-       device->discipline->get_uid(device, &uid);
-       lcu = NULL;
-       spin_lock_irqsave(&aliastree.lock, flags);
-       server = _find_server(&uid);
-       if (server)
-               lcu = _find_lcu(server, &uid);
-       spin_unlock_irqrestore(&aliastree.lock, flags);
-       if (!lcu) {
-               DBF_EVENT_DEVID(DBF_ERR, device->cdev,
-                               "could not find lcu for %04x %02x",
-                               uid.ssid, uid.real_unit_addr);
-               WARN_ON(1);
-               return;
-       }
-       complete_all(&lcu->lcu_setup);
-}
-
-void dasd_alias_wait_for_lcu_setup(struct dasd_device *device)
-{
-       unsigned long flags;
-       struct alias_server *server;
-       struct alias_lcu *lcu;
-       struct dasd_uid uid;
-
-       device->discipline->get_uid(device, &uid);
-       lcu = NULL;
-       spin_lock_irqsave(&aliastree.lock, flags);
-       server = _find_server(&uid);
-       if (server)
-               lcu = _find_lcu(server, &uid);
-       spin_unlock_irqrestore(&aliastree.lock, flags);
-       if (!lcu) {
-               DBF_EVENT_DEVID(DBF_ERR, device->cdev,
-                               "could not find lcu for %04x %02x",
-                               uid.ssid, uid.real_unit_addr);
-               WARN_ON(1);
-               return;
-       }
-       wait_for_completion(&lcu->lcu_setup);
+       return 0;
 }
 
 /*

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index bbcd5e9..1b6e7ea 100644 (file)
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1534,6 +1534,10 @@ static void dasd_eckd_validate_server(struct dasd_device *device)
        struct dasd_eckd_private *private;
        int enable_pav;
 
+       private = (struct dasd_eckd_private *) device->private;
+       if (private->uid.type == UA_BASE_PAV_ALIAS ||
+           private->uid.type == UA_HYPER_PAV_ALIAS)
+               return;
        if (dasd_nopav || MACHINE_IS_VM)
                enable_pav = 0;
        else
@@ -1542,7 +1546,6 @@ static void dasd_eckd_validate_server(struct dasd_device *device)
 
        /* may be requested feature is not available on server,
         * therefore just report error and go ahead */
-       private = (struct dasd_eckd_private *) device->private;
        DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "PSF-SSC for SSID %04x "
                        "returned rc=%d", private->uid.ssid, rc);
 }
@@ -1588,7 +1591,7 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
        struct dasd_eckd_private *private;
        struct dasd_block *block;
        struct dasd_uid temp_uid;
-       int is_known, rc, i;
+       int rc, i;
        int readonly;
        unsigned long value;
 
@@ -1651,22 +1654,12 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
                block->base = device;
        }
 
-       /* register lcu with alias handling, enable PAV if this is a new lcu */
-       is_known = dasd_alias_make_device_known_to_lcu(device);
-       if (is_known < 0) {
-               rc = is_known;
+       /* register lcu with alias handling, enable PAV */
+       rc = dasd_alias_make_device_known_to_lcu(device);
+       if (rc)
                goto out_err2;
-       }
-       /*
-        * dasd_eckd_validate_server is done on the first device that
-        * is found for an LCU. All later other devices have to wait
-        * for it, so they will read the correct feature codes.
-        */
-       if (!is_known) {
-               dasd_eckd_validate_server(device);
-               dasd_alias_lcu_setup_complete(device);
-       } else
-               dasd_alias_wait_for_lcu_setup(device);
+
+       dasd_eckd_validate_server(device);
 
        /* device may report different configuration data after LCU setup */
        rc = dasd_eckd_read_conf(device);
@@ -4098,7 +4091,7 @@ static int dasd_eckd_restore_device(struct dasd_device *device)
 {
        struct dasd_eckd_private *private;
        struct dasd_eckd_characteristics temp_rdc_data;
-       int is_known, rc;
+       int rc;
        struct dasd_uid temp_uid;
        unsigned long flags;
 
@@ -4121,14 +4114,10 @@ static int dasd_eckd_restore_device(struct dasd_device *device)
                goto out_err;
 
        /* register lcu with alias handling, enable PAV if this is a new lcu */
-       is_known = dasd_alias_make_device_known_to_lcu(device);
-       if (is_known < 0)
-               return is_known;
-       if (!is_known) {
-               dasd_eckd_validate_server(device);
-               dasd_alias_lcu_setup_complete(device);
-       } else
-               dasd_alias_wait_for_lcu_setup(device);
+       rc = dasd_alias_make_device_known_to_lcu(device);
+       if (rc)
+               return rc;
+       dasd_eckd_validate_server(device);
 
        /* RE-Read Configuration Data */
        rc = dasd_eckd_read_conf(device);