[PATCH] s390: dasd driver fixes.

s390 dasd driver fixes:
 - Take request queue lock in dasd_end_request.
 - Make it work with CONFIG_DEVFS_FS=y.
 - Properly wait for the root device.
 - Cope with requests killed due to failed channel path.
 - Improve reference counting.
 - Remove devno from struct dasd_device.
 - Remove unnecessary bdget/bdput calls.

drivers/s390/Kconfig

@@ -164,7 +164,7 @@ config DASD_FBA
 
 config DASD_DIAG
 	tristate "Support for DIAG access to CMS reserved Disks"
-	depends on DASD
+	depends on DASD && ARCH_S390X = 'n'
 	help
 	  Select this option if you want to use CMS reserved Disks under VM
 	  with the Diagnose250 command.  If you are not running under VM or

drivers/s390/block/dasd_devmap.c

@@ -11,7 +11,7 @@
  * functions may not be called from interrupt context. In particular
  * dasd_get_device is a no-no from interrupt context.
  *
- * $Revision: 1.11 $
+ * $Revision: 1.12 $
  *
  * History of changes 
  * 05/04/02 split from dasd.c, code restructuring.
@@ -30,6 +30,25 @@
 
 #include "dasd_int.h"
 
+/*
+ * dasd_devmap_t is used to store the features and the relation
+ * between device number and device index. To find a dasd_devmap_t
+ * that corresponds to a device number of a device index each
+ * dasd_devmap_t is added to two linked lists, one to search by
+ * the device number and one to search by the device index. As
+ * soon as big minor numbers are available the device index list
+ * can be removed since the device number will then be identical
+ * to the device index.
+ */
+typedef struct {
+	struct list_head devindex_list;
+	struct list_head devno_list;
+        unsigned int devindex;
+        unsigned short devno;
+        unsigned short features;
+	dasd_device_t *device;
+} dasd_devmap_t;
+
 /*
  * Parameter parsing functions for dasd= parameter. The syntax is:
  *   <devno>		: (0x)?[0-9a-fA-F]+
@@ -278,6 +297,29 @@ dasd_add_range(int from, int to, int features)
 	return 0;
 }
 
+/*
+ * Check if devno has been added to the list of dasd ranges.
+ */
+int
+dasd_devno_in_range(int devno)
+{
+	struct list_head *l;
+	int ret;
+		
+	ret = -ENOENT;
+	spin_lock(&dasd_devmap_lock);
+	/* Find devmap for device with device number devno */
+	list_for_each(l, &dasd_devno_hashlists[devno&255]) {
+		if (list_entry(l, dasd_devmap_t, devno_list)->devno == devno) {
+			/* Found the device. */
+			ret = 0;
+			break;
+		}
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return ret;
+}
+
 /*
  * Forget all about the device numbers added so far.
  * This may only be called at module unload or system shutdown.
@@ -307,7 +349,7 @@ dasd_forget_ranges(void)
  * Find the devmap structure from a devno. Can be removed as soon
  * as big minors are available.
  */
-dasd_devmap_t *
+static dasd_devmap_t *
 dasd_devmap_from_devno(int devno)
 {
 	struct list_head *l;
@@ -332,7 +374,7 @@ dasd_devmap_from_devno(int devno)
  * Find the devmap for a device by its device index. Can be removed
  * as soon as big minors are available.
  */
-dasd_devmap_t *
+static dasd_devmap_t *
 dasd_devmap_from_devindex(int devindex)
 {
 	struct list_head *l;
@@ -353,60 +395,140 @@ dasd_devmap_from_devindex(int devindex)
 	return devmap;
 }
 
-/*
- * Find the device structure for device number devno. If it does not
- * exists yet, allocate it. Increase the reference counter in the device
- * structure and return a pointer to it.
- */
 dasd_device_t *
-dasd_get_device(dasd_devmap_t *devmap)
+dasd_device_from_devindex(int devindex)
 {
+	dasd_devmap_t *devmap;
 	dasd_device_t *device;
 
+	devmap = dasd_devmap_from_devindex(devindex);
 	spin_lock(&dasd_devmap_lock);
 	device = devmap->device;
-	if (device != NULL)
-		atomic_inc(&device->ref_count);
+	if (device)
+		dasd_get_device(device);
+	else
+		device = ERR_PTR(-ENODEV);
 	spin_unlock(&dasd_devmap_lock);
-	if (device != NULL)
 	return device;
+}
+
+/*
+ * Return kdev for a dasd device.
+ */
+kdev_t
+dasd_get_kdev(dasd_device_t *device)
+{
+	dasd_devmap_t *devmap;
+	int major, minor;
+	int devno;
+
+	devno = _ccw_device_get_device_number(device->cdev);
+	devmap = dasd_devmap_from_devno(devno);
+	if (devmap == NULL)
+		return NODEV;
+	major = dasd_gendisk_index_major(devmap->devindex);
+	if (major < 0)
+		return NODEV;
+	minor = devmap->devindex % DASD_PER_MAJOR;
+	return mk_kdev(major, minor);
+}
+
+/*
+ * Create a dasd device structure for cdev.
+ */
+dasd_device_t *
+dasd_create_device(struct ccw_device *cdev)
+{
+	dasd_devmap_t *devmap;
+	dasd_device_t *device;
+	int devno;
+	int rc;
+
+	devno = _ccw_device_get_device_number(cdev);
+	rc = dasd_add_range(devno, devno, DASD_FEATURE_DEFAULT);
+	if (rc)
+		return ERR_PTR(rc);
+
+	if (!(devmap = dasd_devmap_from_devno (devno)))
+		return ERR_PTR(-ENODEV);
 
-	device = dasd_alloc_device(devmap);
+	device = dasd_alloc_device(devmap->devindex);
 	if (IS_ERR(device))
 		return device;
+	atomic_set(&device->ref_count, 1);
+	device->ro_flag = (devmap->features & DASD_FEATURE_READONLY) ? 1 : 0;
+	device->use_diag_flag = 1;
 
-	spin_lock(&dasd_devmap_lock);
-	if (devmap->device != NULL) {
+	spin_lock_irq(get_ccwdev_lock(cdev));
+	if (cdev->dev.driver_data == NULL) {
+		get_device(&cdev->dev);
+		cdev->dev.driver_data = device;
+		device->gdp->driverfs_dev = &cdev->dev;
+		device->cdev = cdev;
+		rc = 0;
+	} else
 		/* Someone else was faster. */
+		rc = -EBUSY;
+	spin_unlock_irq(get_ccwdev_lock(cdev));
+	if (rc) {
 		dasd_free_device(device);
-		device = devmap->device;
-	} else
+		return ERR_PTR(rc);
+	}
+	/* Device created successfully. Make it known via devmap. */
+	spin_lock(&dasd_devmap_lock);
 	devmap->device = device;
-	atomic_inc(&device->ref_count);
-	device->ro_flag = (devmap->features & DASD_FEATURE_READONLY) ? 1 : 0;
-	device->use_diag_flag = 1;
 	spin_unlock(&dasd_devmap_lock);
+
 	return device;
 }
 
 /*
- * Decrease the reference counter of a devices structure. If the
- * reference counter reaches zero and the device status is
- * DASD_STATE_NEW the device structure is freed. 
+ * Wait queue for dasd_delete_device waits.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(dasd_delete_wq);
+
+/*
+ * Remove a dasd device structure.
  */
 void
-dasd_put_device(dasd_devmap_t *devmap)
+dasd_delete_device(dasd_device_t *device)
 {
-	dasd_device_t *device;
+	struct ccw_device *cdev;
+	dasd_devmap_t *devmap;
+	int devno;
 
+	/* First remove device pointer from devmap. */
+	devno = _ccw_device_get_device_number(device->cdev);
+	devmap = dasd_devmap_from_devno (devno);
 	spin_lock(&dasd_devmap_lock);
-	device = devmap->device;
-	if (atomic_dec_return(&device->ref_count) == 0 &&
-	    device->state == DASD_STATE_NEW) {
 	devmap->device = NULL;
-		dasd_free_device(device);
-	}
 	spin_unlock(&dasd_devmap_lock);
+
+	/* Wait for reference counter to drop to zero. */
+	atomic_dec(&device->ref_count);
+	wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
+
+	/* Disconnect dasd_device structure from ccw_device structure. */
+	cdev = device->cdev;
+	device->cdev = NULL;
+	device->gdp->driverfs_dev = NULL;
+	cdev->dev.driver_data = NULL;
+
+	/* Put ccw_device structure. */
+	put_device(&cdev->dev);
+
+	/* Now the device structure can be freed. */
+	dasd_free_device(device);
+}
+
+/*
+ * Reference counter dropped to zero. Wake up waiter
+ * in dasd_delete_device.
+ */
+void
+dasd_put_device_wake(dasd_device_t *device)
+{
+	wake_up(&dasd_delete_wq);
 }
 
 int

drivers/s390/block/dasd_diag.c

@@ -6,7 +6,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
  *
- * $Revision: 1.27 $
+ * $Revision: 1.28 $
  *
  * History of changes
  * 07/13/00 Added fixup sections for diagnoses ans saved some registers
@@ -96,7 +96,7 @@ mdsk_init_io(dasd_device_t * device, int blocksize, int offset, int size)
 	iib = &private->iib;
 	memset(iib, 0, sizeof (diag_init_io_t));
 
-	iib->dev_nr = device->devno;
+	iib->dev_nr = _ccw_device_get_device_number(device->cdev);
 	iib->block_size = blocksize;
 	iib->offset = offset;
 	iib->start_block = 0;
@@ -117,7 +117,7 @@ mdsk_term_io(dasd_device_t * device)
 	private = (dasd_diag_private_t *) device->private;
 	iib = &private->iib;
 	memset(iib, 0, sizeof (diag_init_io_t));
-	iib->dev_nr = device->devno;
+	iib->dev_nr = _ccw_device_get_device_number(device->cdev);
 	rc = dia250(iib, TERM_BIO);
 	return rc & 3;
 }
@@ -134,7 +134,7 @@ dasd_start_diag(dasd_ccw_req_t * cqr)
 	private = (dasd_diag_private_t *) device->private;
 	dreq = (dasd_diag_req_t *) cqr->data;
 
-	private->iob.dev_nr = device->devno;
+	private->iob.dev_nr = _ccw_device_get_device_number(device->cdev);
 	private->iob.key = 0;
 	private->iob.flags = 2;	/* do asynchronous io */
 	private->iob.block_count = dreq->block_count;
@@ -252,7 +252,7 @@ dasd_diag_check_device(dasd_device_t *device)
 	}
 	/* Read Device Characteristics */
 	rdc_data = (void *) &(private->rdc_data);
-	rdc_data->dev_nr = device->devno;
+	rdc_data->dev_nr = _ccw_device_get_device_number(device->cdev);
 	rdc_data->rdc_len = sizeof (dasd_diag_characteristics_t);
 
 	rc = diag210((struct diag210 *) rdc_data);

drivers/s390/block/dasd_eckd.c

@@ -7,7 +7,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
  *
- * $Revision: 1.36 $
+ * $Revision: 1.38 $
  *
  * History of changes (starts July 2000)
  * 07/11/00 Enabled rotational position sensing
@@ -1003,7 +1003,7 @@ dasd_eckd_build_cp(dasd_device_t * device, struct request *req)
 				return ERR_PTR(-EINVAL);
 			count += bv->bv_len >> (device->s2b_shift + 9);
 #if defined(CONFIG_ARCH_S390X)
-			cidaw += idal_nr_words(kmap(bv->bv_page) +
+			cidaw += idal_nr_words(page_address(bv->bv_page) +
 					       bv->bv_offset, bv->bv_len);
 #endif
 		}
@@ -1042,7 +1042,7 @@ dasd_eckd_build_cp(dasd_device_t * device, struct request *req)
 			      last_rec - recid + 1, cmd, device, blksize);
 	}
 	rq_for_each_bio(bio, req) bio_for_each_segment(bv, bio, i) {
-		dst = kmap(bv->bv_page) + bv->bv_offset;
+		dst = page_address(bv->bv_page) + bv->bv_offset;
 		for (off = 0; off < bv->bv_len; off += blksize) {
 			sector_t trkid = recid;
 			unsigned int recoffs = sector_div(trkid, blk_per_trk);
@@ -1453,6 +1453,8 @@ static dasd_discipline_t dasd_eckd_discipline = {
 static int __init
 dasd_eckd_init(void)
 {
+	int ret;
+
 	dasd_ioctl_no_register(THIS_MODULE, BIODASDSATTR,
 			       dasd_eckd_set_attrib);
 	dasd_ioctl_no_register(THIS_MODULE, BIODASDPSRD,
@@ -1466,7 +1468,22 @@ dasd_eckd_init(void)
 
 	ASCEBC(dasd_eckd_discipline.ebcname, 4);
 
-	ccw_driver_register(&dasd_eckd_driver);
+	ret = ccw_driver_register(&dasd_eckd_driver);
+	if (ret) {
+		dasd_ioctl_no_unregister(THIS_MODULE, BIODASDSATTR,
+					 dasd_eckd_set_attrib);
+		dasd_ioctl_no_unregister(THIS_MODULE, BIODASDPSRD,
+					 dasd_eckd_performance);
+		dasd_ioctl_no_unregister(THIS_MODULE, BIODASDRLSE,
+					 dasd_eckd_release);
+		dasd_ioctl_no_unregister(THIS_MODULE, BIODASDRSRV,
+					 dasd_eckd_reserve);
+		dasd_ioctl_no_unregister(THIS_MODULE, BIODASDSLCK,
+					 dasd_eckd_steal_lock);
+		return ret;
+	}
+
+	dasd_generic_auto_online(&dasd_eckd_driver);
 	return 0;
 }
 

drivers/s390/block/dasd_fba.c

@@ -4,7 +4,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
  *
- * $Revision: 1.25 $
+ * $Revision: 1.27 $
  *
  * History of changes
  *	    fixed partition handling and HDIO_GETGEO
@@ -414,9 +414,16 @@ static dasd_discipline_t dasd_fba_discipline = {
 static int __init
 dasd_fba_init(void)
 {
+	int ret;
+
 	ASCEBC(dasd_fba_discipline.ebcname, 4);
 
-	return ccw_driver_register(&dasd_fba_driver);
+	ret = ccw_driver_register(&dasd_fba_driver);
+	if (ret)
+		return ret;
+
+	dasd_generic_auto_online(&dasd_fba_driver);
+	return 0;
 }
 
 static void __exit

drivers/s390/block/dasd_genhd.c

@@ -9,7 +9,7 @@
  *
  * Dealing with devices registered to multiple major numbers.
  *
- * $Revision: 1.23 $
+ * $Revision: 1.24 $
  *
  * History of changes
  * 05/04/02 split from dasd.c, code restructuring.
@@ -108,7 +108,6 @@ dasd_unregister_major(struct major_info * mi)
 struct gendisk *
 dasd_gendisk_alloc(int devindex)
 {
-	struct list_head *l;
 	struct major_info *mi;
 	struct gendisk *gdp;
 	int index, len, rc;
@@ -118,8 +117,7 @@ dasd_gendisk_alloc(int devindex)
 	while (1) {
 		spin_lock(&dasd_major_lock);
 		index = devindex;
-		list_for_each(l, &dasd_major_info) {
-			mi = list_entry(l, struct major_info, list);
+		list_for_each_entry(mi, &dasd_major_info, list) {
 			if (index < DASD_PER_MAJOR)
 				break;
 			index -= DASD_PER_MAJOR;
@@ -142,6 +140,7 @@ dasd_gendisk_alloc(int devindex)
 	gdp->major = mi->major;
 	gdp->first_minor = index << DASD_PARTN_BITS;
 	gdp->fops = &dasd_device_operations;
+	gdp->flags |= GENHD_FL_DEVFS;
 
 	/*
 	 * Set device name.
@@ -191,14 +190,12 @@ static int dasd_gendisk_major_index(int major)
  */
 int dasd_gendisk_index_major(int devindex)
 {
-	struct list_head *l;
 	struct major_info *mi;
 	int rc;
 
 	spin_lock(&dasd_major_lock);
 	rc = -ENODEV;
-	list_for_each(l, &dasd_major_info) {
-		mi = list_entry(l, struct major_info, list);
+	list_for_each_entry(mi, &dasd_major_info, list) {
 		if (devindex < DASD_PER_MAJOR) {
 			rc = mi->major;
 			break;
@@ -231,6 +228,7 @@ void
 dasd_destroy_partitions(dasd_device_t * device)
 {
 	del_gendisk(device->gdp);
+	put_disk(device->gdp);
 }
 
 int

drivers/s390/block/dasd_int.h

@@ -6,7 +6,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
  *
- * $Revision: 1.36 $
+ * $Revision: 1.38 $
  *
  * History of changes (starts July 2000)
  * 02/01/01 added dynamic registration of ioctls
@@ -297,10 +297,6 @@ typedef struct dasd_device_t {
 	struct list_head ccw_chunks;
 	struct list_head erp_chunks;
 
-	/* Common i/o stuff. */
-	/* FIXME: remove the next */
-	int devno;
-
 	atomic_t tasklet_scheduled;
         struct tasklet_struct tasklet;
 	struct work_struct kick_work;
@@ -315,24 +311,23 @@ typedef struct dasd_device_t {
 #endif
 } dasd_device_t;
 
+void dasd_put_device_wake(dasd_device_t *);
+
 /*
- * dasd_devmap_t is used to store the features and the relation
- * between device number and device index. To find a dasd_devmap_t
- * that corresponds to a device number of a device index each
- * dasd_devmap_t is added to two linked lists, one to search by
- * the device number and one to search by the device index. As
- * soon as big minor numbers are available the device index list
- * can be removed since the device number will then be identical
- * to the device index.
+ * Reference count inliners
  */
-typedef struct {
-	struct list_head devindex_list;
-	struct list_head devno_list;
-        unsigned int devindex;
-        unsigned short devno;
-        unsigned short features;
-        dasd_device_t *device;
-} dasd_devmap_t;
+static inline void
+dasd_get_device(dasd_device_t *device)
+{
+	atomic_inc(&device->ref_count);
+}
+
+static inline void
+dasd_put_device(dasd_device_t *device)
+{
+	if (atomic_dec_return(&device->ref_count) == 0)
+		dasd_put_device_wake(device);
+}
 
 /*
  * The static memory in ccw_mem and erp_mem is managed by a sorted
@@ -444,8 +439,9 @@ dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, dasd_device_t *device)
 	return set_normalized_cda(ccw, cda);
 }
 
-dasd_device_t *dasd_alloc_device(dasd_devmap_t *);
+dasd_device_t *dasd_alloc_device(unsigned int devindex);
 void dasd_free_device(dasd_device_t *);
+
 void dasd_enable_device(dasd_device_t *);
 void dasd_set_target_state(dasd_device_t *, int);
 void dasd_kick_device(dasd_device_t *);
@@ -467,6 +463,7 @@ int dasd_generic_remove (struct ccw_device *cdev);
 int dasd_generic_set_online(struct ccw_device *cdev, 
 			    dasd_discipline_t *discipline);
 int dasd_generic_set_offline (struct ccw_device *cdev);
+void dasd_generic_auto_online (struct ccw_driver *);
 
 /* externals in dasd_devmap.c */
 extern int dasd_max_devindex;
@@ -475,13 +472,16 @@ extern int dasd_autodetect;
 
 int dasd_devmap_init(void);
 void dasd_devmap_exit(void);
-dasd_devmap_t *dasd_devmap_from_devno(int);
-dasd_devmap_t *dasd_devmap_from_devindex(int);
-dasd_device_t *dasd_get_device(dasd_devmap_t *);
-void dasd_put_device(dasd_devmap_t *);
+
+dasd_device_t *dasd_create_device(struct ccw_device *);
+void dasd_delete_device(dasd_device_t *);
+
+kdev_t dasd_get_kdev(dasd_device_t *);
+dasd_device_t *dasd_device_from_devindex(int);
 
 int dasd_parse(void);
 int dasd_add_range(int, int, int);
+int dasd_devno_in_range(int);
 
 /* externals in dasd_gendisk.c */
 int  dasd_gendisk_init(void);

drivers/s390/block/dasd_ioctl.c

@@ -12,7 +12,6 @@
  * 05/04/02 split from dasd.c, code restructuring.
  */
 #include <linux/config.h>
-#include <linux/version.h>
 #include <linux/interrupt.h>
 #include <linux/major.h>
 #include <linux/fs.h>
@@ -333,7 +332,7 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
 
 	cdev = device->cdev;
 
-	dasd_info->devno = device->devno;
+	dasd_info->devno = _ccw_device_get_device_number(device->cdev);
 	dasd_info->schid = _ccw_device_get_subchannel_number(device->cdev);
 	dasd_info->cu_type = cdev->id.cu_type;
 	dasd_info->cu_model = cdev->id.cu_model;

drivers/s390/block/dasd_proc.c

@@ -9,7 +9,7 @@
  *
  * /proc interface for the dasd driver.
  *
- * $Revision: 1.17 $
+ * $Revision: 1.18 $
  *
  * History of changes
  * 05/04/02 split from dasd.c, code restructuring.
@@ -56,17 +56,14 @@ dasd_get_user_string(const char *user_buf, size_t user_len)
 static int
 dasd_devices_show(struct seq_file *m, void *v)
 {
-	dasd_devmap_t *devmap;
 	dasd_device_t *device;
 	char *substr;
 
-	devmap = dasd_devmap_from_devindex((unsigned long) v - 1);
-	device = (devmap != NULL) ?
-		dasd_get_device(devmap) : ERR_PTR(-ENODEV);
+	device = dasd_device_from_devindex((unsigned long) v - 1);
 	if (IS_ERR(device))
 		return 0;
 	/* Print device number. */
-	seq_printf(m, "%04x", devmap->devno);
+	seq_printf(m, "%04x", _ccw_device_get_device_number(device->cdev));
 	/* Print discipline string. */
 	if (device != NULL && device->discipline != NULL)
 		seq_printf(m, "(%s)", device->discipline->name);
@@ -113,7 +110,7 @@ dasd_devices_show(struct seq_file *m, void *v)
 		seq_printf(m, "no stat");
 		break;
 	}
-	dasd_put_device(devmap);
+	dasd_put_device(device);
 	if (dasd_probeonly)
 		seq_printf(m, "(probeonly)");
 	seq_printf(m, "\n");