1 files changed, 60 insertions, 13 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index ab84da5592e8..0483b2e76b11 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -82,6 +82,14 @@ static struct ccw_driver dasd_eckd_driver; /* see below */
 #define INIT_CQR_UNFORMATTED 1
 #define INIT_CQR_ERROR 2
 
+/* emergency request for reserve/release */
+static struct {
+        struct dasd_ccw_req cqr;
+        struct ccw1 ccw;
+        char data[32];
+} *dasd_reserve_req;
+static DEFINE_MUTEX(dasd_reserve_mutex);
+
 
 /* initial attempt at a probe function. this can be simplified once
  * the other detection code is gone */
@@ -2645,15 +2653,23 @@ dasd_eckd_release(struct dasd_device *device)
         struct dasd_ccw_req *cqr;
         int rc;
         struct ccw1 *ccw;
+        int useglobal;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
+        useglobal = 0;
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
         if (IS_ERR(cqr)) {
-                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
-                            "Could not allocate initialization request");
-                return PTR_ERR(cqr);
+                mutex_lock(&dasd_reserve_mutex);
+                useglobal = 1;
+                cqr = &dasd_reserve_req->cqr;
+                memset(cqr, 0, sizeof(*cqr));
+                memset(&dasd_reserve_req->ccw, 0,
+                       sizeof(dasd_reserve_req->ccw));
+                cqr->cpaddr = &dasd_reserve_req->ccw;
+                cqr->data = &dasd_reserve_req->data;
+                cqr->magic = DASD_ECKD_MAGIC;
         }
         ccw = cqr->cpaddr;
         ccw->cmd_code = DASD_ECKD_CCW_RELEASE;
@@ -2671,7 +2687,10 @@ dasd_eckd_release(struct dasd_device *device)
 
         rc = dasd_sleep_on_immediatly(cqr);
 
-        dasd_sfree_request(cqr, cqr->memdev);
+        if (useglobal)
+                mutex_unlock(&dasd_reserve_mutex);
+        else
+                dasd_sfree_request(cqr, cqr->memdev);
         return rc;
 }
 
@@ -2687,15 +2706,23 @@ dasd_eckd_reserve(struct dasd_device *device)
         struct dasd_ccw_req *cqr;
         int rc;
         struct ccw1 *ccw;
+        int useglobal;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
+        useglobal = 0;
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
         if (IS_ERR(cqr)) {
-                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
-                            "Could not allocate initialization request");
-                return PTR_ERR(cqr);
+                mutex_lock(&dasd_reserve_mutex);
+                useglobal = 1;
+                cqr = &dasd_reserve_req->cqr;
+                memset(cqr, 0, sizeof(*cqr));
+                memset(&dasd_reserve_req->ccw, 0,
+                       sizeof(dasd_reserve_req->ccw));
+                cqr->cpaddr = &dasd_reserve_req->ccw;
+                cqr->data = &dasd_reserve_req->data;
+                cqr->magic = DASD_ECKD_MAGIC;
         }
         ccw = cqr->cpaddr;
         ccw->cmd_code = DASD_ECKD_CCW_RESERVE;
@@ -2713,7 +2740,10 @@ dasd_eckd_reserve(struct dasd_device *device)
 
         rc = dasd_sleep_on_immediatly(cqr);
 
-        dasd_sfree_request(cqr, cqr->memdev);
+        if (useglobal)
+                mutex_unlock(&dasd_reserve_mutex);
+        else
+                dasd_sfree_request(cqr, cqr->memdev);
         return rc;
 }
 
@@ -2728,15 +2758,23 @@ dasd_eckd_steal_lock(struct dasd_device *device)
         struct dasd_ccw_req *cqr;
         int rc;
         struct ccw1 *ccw;
+        int useglobal;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
+        useglobal = 0;
         cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device);
         if (IS_ERR(cqr)) {
-                DBF_DEV_EVENT(DBF_WARNING, device, "%s",
-                            "Could not allocate initialization request");
-                return PTR_ERR(cqr);
+                mutex_lock(&dasd_reserve_mutex);
+                useglobal = 1;
+                cqr = &dasd_reserve_req->cqr;
+                memset(cqr, 0, sizeof(*cqr));
+                memset(&dasd_reserve_req->ccw, 0,
+                       sizeof(dasd_reserve_req->ccw));
+                cqr->cpaddr = &dasd_reserve_req->ccw;
+                cqr->data = &dasd_reserve_req->data;
+                cqr->magic = DASD_ECKD_MAGIC;
         }
         ccw = cqr->cpaddr;
         ccw->cmd_code = DASD_ECKD_CCW_SLCK;
@@ -2754,7 +2792,10 @@ dasd_eckd_steal_lock(struct dasd_device *device)
 
         rc = dasd_sleep_on_immediatly(cqr);
 
-        dasd_sfree_request(cqr, cqr->memdev);
+        if (useglobal)
+                mutex_unlock(&dasd_reserve_mutex);
+        else
+                dasd_sfree_request(cqr, cqr->memdev);
         return rc;
 }
 
@@ -3488,10 +3529,15 @@ dasd_eckd_init(void)
         int ret;
 
         ASCEBC(dasd_eckd_discipline.ebcname, 4);
+        dasd_reserve_req = kmalloc(sizeof(*dasd_reserve_req),
+                                   GFP_KERNEL | GFP_DMA);
+        if (!dasd_reserve_req)
+                return -ENOMEM;
         ret = ccw_driver_register(&dasd_eckd_driver);
         if (!ret)
                 wait_for_device_probe();
-
+        else
+                kfree(dasd_reserve_req);
         return ret;
 }
 
@@ -3499,6 +3545,7 @@ static void __exit
 dasd_eckd_cleanup(void)
 {
         ccw_driver_unregister(&dasd_eckd_driver);
+        kfree(dasd_reserve_req);
 }
 
 module_init(dasd_eckd_init);