* [PATCH] s390 update (8/9): dasd driver reference counting.
@ 2003-03-26 15:14 Martin Schwidefsky
0 siblings, 0 replies; only message in thread
From: Martin Schwidefsky @ 2003-03-26 15:14 UTC (permalink / raw)
To: linux-kernel, torvalds
* Improve reference counting.
* Remove devno from struct dasd_device.
* Remove unnecessary bdget/bdput calls.
diffstat:
dasd.c | 148 +++++++++++++++------------------------------
dasd_devmap.c | 188 +++++++++++++++++++++++++++++++++++++++++++++++-----------
dasd_diag.c | 10 +--
dasd_genhd.c | 9 --
dasd_int.h | 51 +++++++--------
dasd_ioctl.c | 2
dasd_proc.c | 11 +--
7 files changed, 244 insertions(+), 175 deletions(-)
diff -urN linux-2.5.66/drivers/s390/block/dasd.c linux-2.5.66-s390/drivers/s390/block/dasd.c
--- linux-2.5.66/drivers/s390/block/dasd.c Wed Mar 26 15:45:19 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd.c Wed Mar 26 15:45:19 2003
@@ -7,7 +7,7 @@
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
- * $Revision: 1.81 $
+ * $Revision: 1.82 $
*
* History of changes (starts July 2000)
* 11/09/00 complete redesign after code review
@@ -101,7 +101,7 @@
* Allocate memory for a new device structure.
*/
dasd_device_t *
-dasd_alloc_device(dasd_devmap_t *devmap)
+dasd_alloc_device(unsigned int devindex)
{
dasd_device_t *device;
struct gendisk *gdp;
@@ -111,8 +111,6 @@
return ERR_PTR(-ENOMEM);
memset(device, 0, sizeof (dasd_device_t));
- device->devno = devmap->devno;
-
/* Get two pages for normal block device operations. */
device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
if (device->ccw_mem == NULL) {
@@ -128,7 +126,7 @@
}
/* Allocate gendisk structure for device. */
- gdp = dasd_gendisk_alloc(devmap->devindex);
+ gdp = dasd_gendisk_alloc(devindex);
if (IS_ERR(gdp)) {
free_page((unsigned long) device->erp_mem);
free_pages((unsigned long) device->ccw_mem, 1);
@@ -147,7 +145,7 @@
(unsigned long) device);
INIT_LIST_HEAD(&device->ccw_queue);
init_timer(&device->timer);
- INIT_WORK(&device->kick_work, do_kick_device, (void *) (addr_t) device->devno);
+ INIT_WORK(&device->kick_work, do_kick_device, device);
device->state = DASD_STATE_NEW;
device->target = DASD_STATE_NEW;
@@ -174,22 +172,19 @@
static inline int
dasd_state_new_to_known(dasd_device_t *device)
{
- dasd_devmap_t *devmap;
umode_t devfs_perm;
- int major, minor;
+ kdev_t kdev;
char buf[20];
- /* Increase reference count of bdev. */
- if (bdget(MKDEV(device->gdp->major, device->gdp->first_minor)) == NULL)
+ kdev = dasd_get_kdev(device);
+ if (kdev_none(kdev))
return -ENODEV;
- devmap = dasd_devmap_from_devno(device->devno);
- if (devmap == NULL)
- return -ENODEV;
- major = dasd_gendisk_index_major(devmap->devindex);
- if (major < 0)
- return -ENODEV;
- minor = devmap->devindex % DASD_PER_MAJOR;
+ /*
+ * As long as the device is not in state DASD_STATE_NEW we want to
+ * keep the reference count > 0.
+ */
+ dasd_get_device(device);
#ifdef CONFIG_DEVFS_FS
/* Add a proc directory and the dasd device entry to devfs. */
@@ -201,9 +196,11 @@
else
devfs_perm = S_IFBLK | S_IRUSR | S_IWUSR;
- snprintf(buf, sizeof(buf), "dasd/%04x/device", device->devno);
+ snprintf(buf, sizeof(buf), "dasd/%04x/device",
+ _ccw_device_get_device_number(device->cdev));
device->devfs_entry = devfs_register(NULL, buf, 0,
- major, minor << DASD_PARTN_BITS,
+ major(kdev),
+ minor(kdev) << DASD_PARTN_BITS,
devfs_perm,
&dasd_device_operations, NULL);
device->state = DASD_STATE_KNOWN;
@@ -216,8 +213,6 @@
static inline void
dasd_state_known_to_new(dasd_device_t * device)
{
- struct block_device *bdev;
-
/* Remove device entry and devfs directory. */
devfs_unregister(device->devfs_entry);
devfs_unregister(device->gdp->de);
@@ -226,10 +221,8 @@
device->discipline = NULL;
device->state = DASD_STATE_NEW;
- /* Decrease reference count of bdev. */
- bdev = bdget(MKDEV(device->gdp->major, device->gdp->first_minor));
- bdput(bdev);
- bdput(bdev);
+ /* Give up reference we took in dasd_state_new_to_known. */
+ dasd_put_device(device);
}
/*
@@ -429,7 +422,8 @@
if (rc && rc != -EAGAIN) {
if (rc != -ENODEV)
MESSAGE (KERN_INFO, "giving up on dasd device with "
- "devno %04x", device->devno);
+ "devno %04x",
+ _ccw_device_get_device_number(device->cdev));
device->target = device->state;
}
@@ -446,26 +440,18 @@
static void
do_kick_device(void *data)
{
- int devno;
- dasd_devmap_t *devmap;
dasd_device_t *device;
- devno = (long) data;
- devmap = dasd_devmap_from_devno(devno);
- device = (devmap != NULL) ?
- dasd_get_device(devmap) : ERR_PTR(-ENODEV);
- if (IS_ERR(device))
- return;
- atomic_dec(&device->ref_count);
+ device = (dasd_device_t *) data;
dasd_change_state(device);
dasd_schedule_bh(device);
- dasd_put_device(devmap);
+ dasd_put_device(device);
}
void
dasd_kick_device(dasd_device_t *device)
{
- atomic_inc(&device->ref_count);
+ dasd_get_device(device);
/* queue call to dasd_kick_device to the kernel event daemon. */
schedule_work(&device->kick_work);
}
@@ -647,7 +633,7 @@
}
strncpy((char *) &cqr->magic, magic, 4);
ASCEBC((char *) &cqr->magic, 4);
- atomic_inc(&device->ref_count);
+ dasd_get_device(device);
return cqr;
}
@@ -694,7 +680,7 @@
}
strncpy((char *) &cqr->magic, magic, 4);
ASCEBC((char *) &cqr->magic, 4);
- atomic_inc(&device->ref_count);
+ dasd_get_device(device);
return cqr;
}
@@ -724,7 +710,7 @@
if (cqr->data != NULL)
kfree(cqr->data);
kfree(cqr);
- atomic_dec(&device->ref_count);
+ dasd_put_device(device);
}
void
@@ -739,7 +725,7 @@
spin_lock_irqsave(&device->mem_lock, flags);
dasd_free_chunk(&device->ccw_chunks, cqr);
spin_unlock_irqrestore(&device->mem_lock, flags);
- atomic_dec(&device->ref_count);
+ dasd_put_device(device);
}
/*
@@ -937,19 +923,14 @@
struct work_struct work;
dasd_device_t *device;
} *p;
- dasd_devmap_t *devmap;
dasd_device_t *device;
dasd_ccw_req_t *cqr;
- int devno;
p = data;
device = p->device;
DBF_EVENT(DBF_NOTICE, "State change Interrupt for bus_id %s",
device->cdev->dev.bus_id);
- // FIXME: get rid of devmap.
- devno = _ccw_device_get_device_number(device->cdev);
- devmap = dasd_devmap_from_devno(devno);
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* re-activate first request in queue */
if (!list_empty(&device->ccw_queue)) {
@@ -966,7 +947,7 @@
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
dasd_schedule_bh(device);
- dasd_put_device(devmap);
+ dasd_put_device(device);
kfree(p);
}
@@ -1014,8 +995,7 @@
return;
INIT_WORK(&p->work, (void *) do_state_change_pending, p);
p->device = device;
- atomic_inc(&device->ref_count);
- /* queue call to do_state_change_pending to the kernel event daemon. */
+ dasd_get_device(device);
schedule_work(&p->work);
}
@@ -1143,7 +1123,6 @@
BUG();
add_disk_randomness(req->rq_disk);
end_that_request_last(req);
- return;
}
/*
@@ -1226,7 +1205,6 @@
__dasd_process_blk_queue(dasd_device_t * device)
{
request_queue_t *queue;
- struct list_head *l;
struct request *req;
dasd_ccw_req_t *cqr;
int nr_queued;
@@ -1248,11 +1226,9 @@
return;
nr_queued = 0;
/* Now we try to fetch requests from the request queue */
- list_for_each(l, &device->ccw_queue) {
- cqr = list_entry(l, dasd_ccw_req_t, list);
+ list_for_each_entry(cqr, &device->ccw_queue, list)
if (cqr->status == DASD_CQR_QUEUED)
nr_queued++;
- }
while (!blk_queue_plugged(queue) &&
!blk_queue_empty(queue) &&
nr_queued < DASD_CHANQ_MAX_SIZE) {
@@ -1260,7 +1236,8 @@
if (device->ro_flag && rq_data_dir(req) == WRITE) {
DBF_EVENT(DBF_ERR,
"(%04x) Rejecting write request %p",
- device->devno, req);
+ _ccw_device_get_device_number(device->cdev),
+ req);
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
continue;
@@ -1271,7 +1248,8 @@
break; /* terminate request queue loop */
DBF_EVENT(DBF_ERR,
"(%04x) CCW creation failed on request %p",
- device->devno, req);
+ _ccw_device_get_device_number(device->cdev),
+ req);
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
continue;
@@ -1408,8 +1386,7 @@
__dasd_start_head(device);
spin_unlock(get_ccwdev_lock(device->cdev));
spin_unlock_irq(&device->request_queue_lock);
- /* FIXME: what if ref_count == 0 && state == DASD_STATE_NEW ?? */
- atomic_dec(&device->ref_count);
+ dasd_put_device(device);
}
/*
@@ -1421,7 +1398,7 @@
/* Protect against rescheduling. */
if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
return;
- atomic_inc(&device->ref_count);
+ dasd_get_device(device);
tasklet_hi_schedule(&device->tasklet);
}
@@ -1803,8 +1780,8 @@
return 0;
}
-struct
-block_device_operations dasd_device_operations = {
+struct block_device_operations
+dasd_device_operations = {
.owner = THIS_MODULE,
.open = dasd_open,
.release = dasd_release,
@@ -1885,30 +1862,12 @@
dasd_discipline_t *discipline)
{
- int devno;
- dasd_devmap_t *devmap;
dasd_device_t *device;
int rc;
- if (cdev->dev.driver_data != NULL) /* already enabled */
- return 0;
-
- devno = _ccw_device_get_device_number(cdev);
- rc = dasd_add_range(devno, devno, DASD_FEATURE_DEFAULT);
- if (rc)
- return rc;
-
- if (!(devmap = dasd_devmap_from_devno (devno)))
- return 0; /* device is still disabled -> ignore it */
-
- if (IS_ERR(device = dasd_get_device(devmap))) {
- printk (KERN_WARNING "dasd_generic could not get %s\n",
- cdev->dev.bus_id);
+ device = dasd_create_device(cdev);
+ if (IS_ERR(device))
return PTR_ERR(device);
- }
-
- device->gdp->driverfs_dev = &cdev->dev;
- device->cdev = cdev;
if (device->use_diag_flag)
device->discipline = dasd_diag_discipline_pointer;
@@ -1929,7 +1888,7 @@
if (rc) {
printk (KERN_WARNING "dasd_generic found a bad device %s\n",
cdev->dev.bus_id);
- dasd_put_device(devmap);
+ dasd_delete_device(device);
return rc;
}
@@ -1940,16 +1899,17 @@
cdev->dev.bus_id);
rc = -ENODEV;
dasd_set_target_state(device, DASD_STATE_NEW);
+ dasd_delete_device(device);
} else {
pr_debug("dasd_generic device %s found\n",
cdev->dev.bus_id);
cdev->dev.driver_data = device;
}
- dasd_put_device(devmap);
/* FIXME: we have to wait for the root device but we don't want
* to wait for each single device but for all at once. */
wait_event(dasd_init_waitq, _wait_for_device(device));
+
return rc;
}
@@ -1957,21 +1917,16 @@
dasd_generic_set_offline (struct ccw_device *cdev)
{
dasd_device_t *device;
- dasd_devmap_t *devmap;
- int devno;
- devno = _ccw_device_get_device_number(cdev);
device = cdev->dev.driver_data;
- devmap = dasd_devmap_from_devno(devno);
- if (device == NULL || devmap == NULL)
- return -ENODEV;
-
- device = dasd_get_device(devmap);
- if (IS_ERR(device))
- return PTR_ERR(device);
-
+ if (atomic_read(&device->open_count) > 0) {
+ printk (KERN_WARNING "Can't offline dasd device with open"
+ " count = %i.\n",
+ atomic_read(&device->open_count));
+ return -EBUSY;
+ }
dasd_set_target_state(device, DASD_STATE_NEW);
- dasd_put_device(devmap);
+ dasd_delete_device(device);
return 0;
}
@@ -1999,8 +1954,7 @@
continue;
cdev = to_ccwdev(dev);
devno = _ccw_device_get_device_number(cdev);
- if (dasd_autodetect ||
- dasd_devmap_from_devno(devno) != 0)
+ if (dasd_autodetect || dasd_devno_in_range(devno) == 0)
ccw_device_set_online(cdev);
put_device(dev);
}
diff -urN linux-2.5.66/drivers/s390/block/dasd_devmap.c linux-2.5.66-s390/drivers/s390/block/dasd_devmap.c
--- linux-2.5.66/drivers/s390/block/dasd_devmap.c Mon Mar 24 23:00:40 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_devmap.c Wed Mar 26 15:45:19 2003
@@ -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.
@@ -31,6 +31,25 @@
#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]+
* <feature> : ro
@@ -279,6 +298,29 @@
}
/*
+ * 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 @@
* 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 @@
* 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 @@
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 device;
+}
- device = dasd_alloc_device(devmap);
+/*
+ * 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->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
- devmap->device = device;
- atomic_inc(&device->ref_count);
- device->ro_flag = (devmap->features & DASD_FEATURE_READONLY) ? 1 : 0;
- device->use_diag_flag = 1;
+ return ERR_PTR(rc);
+ }
+ /* Device created successfully. Make it known via devmap. */
+ spin_lock(&dasd_devmap_lock);
+ devmap->device = device;
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);
- }
+ devmap->device = NULL;
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
diff -urN linux-2.5.66/drivers/s390/block/dasd_diag.c linux-2.5.66-s390/drivers/s390/block/dasd_diag.c
--- linux-2.5.66/drivers/s390/block/dasd_diag.c Mon Mar 24 22:59:54 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_diag.c Wed Mar 26 15:45:19 2003
@@ -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 @@
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 @@
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 @@
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 @@
}
/* 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);
diff -urN linux-2.5.66/drivers/s390/block/dasd_genhd.c linux-2.5.66-s390/drivers/s390/block/dasd_genhd.c
--- linux-2.5.66/drivers/s390/block/dasd_genhd.c Wed Mar 26 15:45:19 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_genhd.c Wed Mar 26 15:45:19 2003
@@ -108,7 +108,6 @@
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 @@
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;
@@ -192,14 +190,12 @@
*/
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;
@@ -232,6 +228,7 @@
dasd_destroy_partitions(dasd_device_t * device)
{
del_gendisk(device->gdp);
+ put_disk(device->gdp);
}
int
diff -urN linux-2.5.66/drivers/s390/block/dasd_int.h linux-2.5.66-s390/drivers/s390/block/dasd_int.h
--- linux-2.5.66/drivers/s390/block/dasd_int.h Wed Mar 26 15:45:19 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_int.h Wed Mar 26 15:45:19 2003
@@ -6,7 +6,7 @@
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
*
- * $Revision: 1.37 $
+ * $Revision: 1.38 $
*
* History of changes (starts July 2000)
* 02/01/01 added dynamic registration of ioctls
@@ -297,10 +297,6 @@
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 @@
#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 @@
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 *);
@@ -476,13 +472,16 @@
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);
diff -urN linux-2.5.66/drivers/s390/block/dasd_ioctl.c linux-2.5.66-s390/drivers/s390/block/dasd_ioctl.c
--- linux-2.5.66/drivers/s390/block/dasd_ioctl.c Mon Mar 24 23:00:48 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_ioctl.c Wed Mar 26 15:45:19 2003
@@ -333,7 +333,7 @@
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;
diff -urN linux-2.5.66/drivers/s390/block/dasd_proc.c linux-2.5.66-s390/drivers/s390/block/dasd_proc.c
--- linux-2.5.66/drivers/s390/block/dasd_proc.c Mon Mar 24 23:00:09 2003
+++ linux-2.5.66-s390/drivers/s390/block/dasd_proc.c Wed Mar 26 15:45:19 2003
@@ -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 @@
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 @@
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");
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2003-03-26 15:14 [PATCH] s390 update (8/9): dasd driver reference counting Martin Schwidefsky
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