From: Jan Glauber <jglauber@redhat.com>
Subject: [RHEL5.1 PATCH] s390: runtime switch for dasd erp logging
Date: Tue, 20 Feb 2007 15:51:26 +0100
Bugzilla: 228034
Message-Id: <1171983086.6031.30.camel@localhost.localdomain>
Changelog: [s390] runtime switch for dasd erp logging


BZ 228034

This patch reworks the dasd driver erp (error recovery procedure) logging
to be switchable via a sysfs attribute.

The patch also fixes a build warning from a misplaced __exit (I would not have 
opened a bugzilla for it but compile warnings are annoying to me).

Jan
-- 
jglauber@redhat.com
jang@de.ibm.com

 arch/s390/kernel/vmlinux.lds.S     |    2 -
 drivers/s390/block/dasd.c          |    8 ++---
 drivers/s390/block/dasd_3990_erp.c |   23 ++++++-----------
 drivers/s390/block/dasd_devmap.c   |   50 +++++++++++++++++++++++++++++++++++++
 drivers/s390/block/dasd_eer.c      |    2 -
 drivers/s390/block/dasd_int.h      |    4 --
 include/asm-s390/dasd.h            |    1 
 7 files changed, 66 insertions(+), 24 deletions(-)

diff -urNp linux-2.6.18.s390/arch/s390/kernel/vmlinux.lds.S linux-2.6.18.s390.dasd/arch/s390/kernel/vmlinux.lds.S
--- linux-2.6.18.s390/arch/s390/kernel/vmlinux.lds.S	2007-02-20 14:55:41.000000000 +0100
+++ linux-2.6.18.s390.dasd/arch/s390/kernel/vmlinux.lds.S	2007-02-20 15:06:34.000000000 +0100
@@ -118,7 +118,7 @@ SECTIONS
 
   /* Sections to be discarded */
   /DISCARD/ : {
-	*(.exitcall.exit)
+	*(.exit.text) *(.exit.data) *(.exitcall.exit)
 	}
 
   /* Stabs debugging sections.  */
diff -urNp linux-2.6.18.s390/drivers/s390/block/dasd.c linux-2.6.18.s390.dasd/drivers/s390/block/dasd.c
--- linux-2.6.18.s390/drivers/s390/block/dasd.c	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/drivers/s390/block/dasd.c	2007-02-20 15:05:28.000000000 +0100
@@ -1051,10 +1051,10 @@ dasd_int_handler(struct ccw_device *cdev
 		}
 	} else {		/* error */
 		memcpy(&cqr->irb, irb, sizeof (struct irb));
-#ifdef ERP_DEBUG
-		/* dump sense data */
-		dasd_log_sense(cqr, irb);
-#endif
+		if (device->features & DASD_FEATURE_ERPLOG) {
+			/* dump sense data */
+			dasd_log_sense(cqr, irb);
+		}
 		switch (era) {
 		case dasd_era_fatal:
 			cqr->status = DASD_CQR_FAILED;
diff -urNp linux-2.6.18.s390/drivers/s390/block/dasd_3990_erp.c linux-2.6.18.s390.dasd/drivers/s390/block/dasd_3990_erp.c
--- linux-2.6.18.s390/drivers/s390/block/dasd_3990_erp.c	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/drivers/s390/block/dasd_3990_erp.c	2007-02-20 15:05:28.000000000 +0100
@@ -2641,14 +2641,12 @@ dasd_3990_erp_action(struct dasd_ccw_req
 	struct dasd_ccw_req *erp = NULL;
 	struct dasd_device *device = cqr->device;
 	__u32 cpa = cqr->irb.scsw.cpa;
+	struct dasd_ccw_req *temp_erp = NULL;
 
-#ifdef ERP_DEBUG
-	/* print current erp_chain */
-	DEV_MESSAGE(KERN_ERR, device, "%s",
-		    "ERP chain at BEGINNING of ERP-ACTION");
-	{
-		struct dasd_ccw_req *temp_erp = NULL;
-
+	if (device->features & DASD_FEATURE_ERPLOG) {
+		/* print current erp_chain */
+		DEV_MESSAGE(KERN_ERR, device, "%s",
+			    "ERP chain at BEGINNING of ERP-ACTION");
 		for (temp_erp = cqr;
 		     temp_erp != NULL; temp_erp = temp_erp->refers) {
 
@@ -2658,7 +2656,6 @@ dasd_3990_erp_action(struct dasd_ccw_req
 				    temp_erp->refers);
 		}
 	}
-#endif				/* ERP_DEBUG */
 
 	/* double-check if current erp/cqr was successfull */
 	if ((cqr->irb.scsw.cstat == 0x00) &&
@@ -2695,11 +2692,10 @@ dasd_3990_erp_action(struct dasd_ccw_req
 		erp = dasd_3990_erp_handle_match_erp(cqr, erp);
 	}
 
-#ifdef ERP_DEBUG
-	/* print current erp_chain */
-	DEV_MESSAGE(KERN_ERR, device, "%s", "ERP chain at END of ERP-ACTION");
-	{
-		struct dasd_ccw_req *temp_erp = NULL;
+	if (device->features & DASD_FEATURE_ERPLOG) {
+		/* print current erp_chain */
+		DEV_MESSAGE(KERN_ERR, device, "%s",
+			    "ERP chain at END of ERP-ACTION");
 		for (temp_erp = erp;
 		     temp_erp != NULL; temp_erp = temp_erp->refers) {
 
@@ -2709,7 +2705,6 @@ dasd_3990_erp_action(struct dasd_ccw_req
 				    temp_erp->refers);
 		}
 	}
-#endif				/* ERP_DEBUG */
 
 	if (erp->status == DASD_CQR_FAILED)
 		dasd_log_ccw(erp, 1, cpa);
diff -urNp linux-2.6.18.s390/drivers/s390/block/dasd_devmap.c linux-2.6.18.s390.dasd/drivers/s390/block/dasd_devmap.c
--- linux-2.6.18.s390/drivers/s390/block/dasd_devmap.c	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/drivers/s390/block/dasd_devmap.c	2007-02-20 15:05:28.000000000 +0100
@@ -202,6 +202,8 @@ dasd_feature_list(char *str, char **endp
 			features |= DASD_FEATURE_READONLY;
 		else if (len == 4 && !strncmp(str, "diag", 4))
 			features |= DASD_FEATURE_USEDIAG;
+		else if (len == 6 && !strncmp(str, "erplog", 6))
+			features |= DASD_FEATURE_ERPLOG;
 		else {
 			MESSAGE(KERN_WARNING,
 				"unsupported feature: %*s, "
@@ -681,6 +683,53 @@ dasd_ro_store(struct device *dev, struct
 static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_store);
 
 /*
+ * erplog controls the logging of ERP related data
+ * (e.g. failing channel programs).
+ */
+static ssize_t
+dasd_erplog_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int erplog;
+
+	devmap = dasd_find_busid(dev->bus_id);
+	if (!IS_ERR(devmap))
+		erplog = (devmap->features & DASD_FEATURE_ERPLOG) != 0;
+	else
+		erplog = (DASD_FEATURE_DEFAULT & DASD_FEATURE_ERPLOG) != 0;
+	return snprintf(buf, PAGE_SIZE, erplog ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_erplog_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	struct dasd_devmap *devmap;
+	int val;
+	char *endp;
+
+	devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+
+	val = simple_strtoul(buf, &endp, 0);
+	if (((endp + 1) < (buf + count)) || (val > 1))
+		return -EINVAL;
+
+	spin_lock(&dasd_devmap_lock);
+	if (val)
+		devmap->features |= DASD_FEATURE_ERPLOG;
+	else
+		devmap->features &= ~DASD_FEATURE_ERPLOG;
+	if (devmap->device)
+		devmap->device->features = devmap->features;
+	spin_unlock(&dasd_devmap_lock);
+	return count;
+}
+
+static DEVICE_ATTR(erplog, 0644, dasd_erplog_show, dasd_erplog_store);
+
+/*
  * use_diag controls whether the driver should use diag rather than ssch
  * to talk to the device
  */
@@ -854,6 +903,7 @@ static struct attribute * dasd_attrs[] =
 	&dev_attr_uid.attr,
 	&dev_attr_use_diag.attr,
 	&dev_attr_eer_enabled.attr,
+	&dev_attr_erplog.attr,
 	NULL,
 };
 
diff -urNp linux-2.6.18.s390/drivers/s390/block/dasd_eer.c linux-2.6.18.s390.dasd/drivers/s390/block/dasd_eer.c
--- linux-2.6.18.s390/drivers/s390/block/dasd_eer.c	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/drivers/s390/block/dasd_eer.c	2007-02-20 15:06:34.000000000 +0100
@@ -678,7 +678,7 @@ int __init dasd_eer_init(void)
 	return 0;
 }
 
-void __exit dasd_eer_exit(void)
+void dasd_eer_exit(void)
 {
 	WARN_ON(misc_deregister(&dasd_eer_dev) != 0);
 }
diff -urNp linux-2.6.18.s390/drivers/s390/block/dasd_int.h linux-2.6.18.s390.dasd/drivers/s390/block/dasd_int.h
--- linux-2.6.18.s390/drivers/s390/block/dasd_int.h	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/drivers/s390/block/dasd_int.h	2007-02-20 15:05:28.000000000 +0100
@@ -13,10 +13,6 @@
 
 #ifdef __KERNEL__
 
-/* erp debugging in dasd.c and dasd_3990_erp.c */
-#define ERP_DEBUG
-
-
 /* we keep old device allocation scheme; IOW, minors are still in 0..255 */
 #define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
diff -urNp linux-2.6.18.s390/include/asm-s390/dasd.h linux-2.6.18.s390.dasd/include/asm-s390/dasd.h
--- linux-2.6.18.s390/include/asm-s390/dasd.h	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.s390.dasd/include/asm-s390/dasd.h	2007-02-20 15:05:28.000000000 +0100
@@ -74,6 +74,7 @@ typedef struct dasd_information2_t {
 #define DASD_FEATURE_READONLY	     0x01
 #define DASD_FEATURE_USEDIAG	     0x02
 #define DASD_FEATURE_INITIAL_ONLINE  0x04
+#define DASD_FEATURE_ERPLOG	     0x08
 
 #define DASD_PARTN_BITS 2
 

--- linux-rhel5/arch/s390/hypfs/hypfs_diag.c.exit
+++ linux-rhel5/arch/s390/hypfs/hypfs_diag.c
@@ -531,7 +531,7 @@ __init int hypfs_diag_init(void)
 	return rc;
 }
 
-__exit void hypfs_diag_exit(void)
+void hypfs_diag_exit(void)
 {
 	diag224_delete_name_table();
 	diag204_free_buffer();