From 184e0aefe61a0b3f52701c8143fafb3d0f8b9bc0 Mon Sep 17 00:00:00 2001
From: Stefan Weinhuber <wein@de.ibm.com>
Date: Mon, 9 Aug 2010 18:12:59 +0200
Subject: [PATCH] --- yaml --- r: 207864 b: refs/heads/master c:
 f932bcea6b7317312ab38df12a84710fc6c67a81 h: refs/heads/master v: v3

---
 [refs]                               |  2 +-
 trunk/drivers/s390/block/dasd_eckd.c | 73 +++++++++++++++++++++++-----
 2 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/[refs] b/[refs]
index 64983c092791..b11254a16f50 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: eafd2b6ddd8604998bdfbf7550b23795c07f03bb
+refs/heads/master: f932bcea6b7317312ab38df12a84710fc6c67a81
diff --git a/trunk/drivers/s390/block/dasd_eckd.c b/trunk/drivers/s390/block/dasd_eckd.c
index ab84da5592e8..0483b2e76b11 100644
--- a/trunk/drivers/s390/block/dasd_eckd.c
+++ b/trunk/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);