[PATCH] s390 (3/4): block device driver.

From: Martin Schwidefsky
Date: Wed Jun 02 2004 - 05:59:27 EST

[PATCH] s390: block device driver.

From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>

block device driver changes:
- dasd: Fix diag discipline if it is loaded as a module.
- dcssblk: Replace r/w lock with r/w semaphore to be able to call
device_register inside a critical section.
- dcssblk: Fix error handling in write function for dcss "add" attribute.
- xpram & dcssblk: Fix sanity check for sector number.

diffstat:
drivers/s390/block/dasd.c | 6 +-
drivers/s390/block/dasd_diag.c | 8 ++
drivers/s390/block/dasd_int.h | 9 ---
drivers/s390/block/dcssblk.c | 114 +++++++++++++++++++----------------------
drivers/s390/block/xpram.c | 2
5 files changed, 68 insertions(+), 71 deletions(-)

diff -urN linux-2.6/drivers/s390/block/dasd.c linux-2.6-s390/drivers/s390/block/dasd.c
--- linux-2.6/drivers/s390/block/dasd.c Wed Jun 2 11:29:04 2004
+++ linux-2.6-s390/drivers/s390/block/dasd.c Wed Jun 2 11:29:39 2004
@@ -7,7 +7,7 @@
* Bugreports.to..: <Linux390@xxxxxxxxxx>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
- * $Revision: 1.141 $
+ * $Revision: 1.142 $
*/

#include <linux/config.h>
@@ -37,6 +37,7 @@
* SECTION: exported variables of dasd.c
*/
debug_info_t *dasd_debug_area;
+struct dasd_discipline *dasd_diag_discipline_pointer;

MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@xxxxxxxxxx>");
MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
@@ -1990,6 +1991,8 @@

DBF_EVENT(DBF_EMERG, "%s", "debug area created");

+ dasd_diag_discipline_pointer = NULL;
+
rc = devfs_mk_dir("dasd");
if (rc)
goto failed;
@@ -2022,6 +2025,7 @@
module_exit(dasd_exit);

EXPORT_SYMBOL(dasd_debug_area);
+EXPORT_SYMBOL(dasd_diag_discipline_pointer);

EXPORT_SYMBOL(dasd_add_request_head);
EXPORT_SYMBOL(dasd_add_request_tail);
diff -urN linux-2.6/drivers/s390/block/dasd_diag.c linux-2.6-s390/drivers/s390/block/dasd_diag.c
--- linux-2.6/drivers/s390/block/dasd_diag.c Mon May 10 04:31:58 2004
+++ linux-2.6-s390/drivers/s390/block/dasd_diag.c Wed Jun 2 11:29:39 2004
@@ -6,7 +6,7 @@
* Bugreports.to..: <Linux390@xxxxxxxxxx>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
*
- * $Revision: 1.34 $
+ * $Revision: 1.36 $
*/

#include <linux/config.h>
@@ -35,6 +35,8 @@

MODULE_LICENSE("GPL");

+struct dasd_discipline dasd_diag_discipline;
+
struct dasd_diag_private {
struct dasd_diag_characteristics rdc_data;
struct dasd_diag_rw_io iob;
@@ -292,7 +294,7 @@
mdsk_term_io(device);
}
if (bsize <= PAGE_SIZE && label[3] == bsize &&
- label[0] == 0xc3d4e2f1 && label[13] != 0) {
+ label[0] == 0xc3d4e2f1) {
device->blocks = label[7];
device->bp_block = bsize;
device->s2b_shift = 0; /* bits to shift 512 to get a block */
@@ -489,6 +491,7 @@

ctl_set_bit(0, 9);
register_external_interrupt(0x2603, dasd_ext_handler);
+ dasd_diag_discipline_pointer = &dasd_diag_discipline;
return 0;
}

@@ -503,6 +506,7 @@
}
unregister_external_interrupt(0x2603, dasd_ext_handler);
ctl_clear_bit(0, 9);
+ dasd_diag_discipline_pointer = NULL;
}

module_init(dasd_diag_init);
diff -urN linux-2.6/drivers/s390/block/dasd_int.h linux-2.6-s390/drivers/s390/block/dasd_int.h
--- linux-2.6/drivers/s390/block/dasd_int.h Mon May 10 04:32:54 2004
+++ linux-2.6-s390/drivers/s390/block/dasd_int.h Wed Jun 2 11:29:39 2004
@@ -6,7 +6,7 @@
* Bugreports.to..: <Linux390@xxxxxxxxxx>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
*
- * $Revision: 1.57 $
+ * $Revision: 1.58 $
*/

#ifndef DASD_INT_H
@@ -260,12 +260,7 @@
int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
};

-extern struct dasd_discipline dasd_diag_discipline;
-#ifdef CONFIG_DASD_DIAG
-#define dasd_diag_discipline_pointer (&dasd_diag_discipline)
-#else
-#define dasd_diag_discipline_pointer (0)
-#endif
+extern struct dasd_discipline *dasd_diag_discipline_pointer;

struct dasd_device {
/* Block device stuff. */
diff -urN linux-2.6/drivers/s390/block/dcssblk.c linux-2.6-s390/drivers/s390/block/dcssblk.c
--- linux-2.6/drivers/s390/block/dcssblk.c Mon May 10 04:32:25 2004
+++ linux-2.6-s390/drivers/s390/block/dcssblk.c Wed Jun 2 11:29:39 2004
@@ -76,8 +76,7 @@
};

static struct list_head dcssblk_devices = LIST_HEAD_INIT(dcssblk_devices);
-static rwlock_t dcssblk_devices_lock = RW_LOCK_UNLOCKED;
-
+static struct rw_semaphore dcssblk_devices_sem;

/*
* release function for segment device.
@@ -92,8 +91,8 @@

/*
* get a minor number. needs to be called with
- * write_lock(&dcssblk_devices_lock) and the
- * device needs to be enqueued before the lock is
+ * down_write(&dcssblk_devices_sem) and the
+ * device needs to be enqueued before the semaphore is
* freed.
*/
static inline int
@@ -121,7 +120,7 @@
/*
* get the struct dcssblk_dev_info from dcssblk_devices
* for the given name.
- * read_lock(&dcssblk_devices_lock) must be held.
+ * down_read(&dcssblk_devices_sem) must be held.
*/
static struct dcssblk_dev_info *
dcssblk_get_device_by_name(char *name)
@@ -137,31 +136,6 @@
}

/*
- * register the device that represents a segment in sysfs,
- * also add the attributes for the device
- */
-static inline int
-dcssblk_register_segment_device(struct device *dev)
-{
- int rc;
-
- rc = device_register(dev);
- if (rc)
- return rc;
- rc = device_create_file(dev, &dev_attr_shared);
- if (rc)
- goto unregister_dev;
- rc = device_create_file(dev, &dev_attr_save);
- if (rc)
- goto unregister_dev;
- return rc;
-
-unregister_dev:
- device_unregister(dev);
- return rc;
-}
-
-/*
* device attribute for switching shared/nonshared (exclusive)
* operation (show + store)
*/
@@ -184,24 +158,24 @@
PRINT_WARN("Invalid value, must be 0 or 1\n");
return -EINVAL;
}
- write_lock(&dcssblk_devices_lock);
+ down_write(&dcssblk_devices_sem);
dev_info = container_of(dev, struct dcssblk_dev_info, dev);
if (atomic_read(&dev_info->use_count)) {
PRINT_ERR("share: segment %s is busy!\n",
dev_info->segment_name);
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
return -EBUSY;
}
if ((inbuf[0] == '1') && (dev_info->is_shared == 1)) {
PRINT_WARN("Segment %s already loaded in shared mode!\n",
dev_info->segment_name);
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
return count;
}
if ((inbuf[0] == '0') && (dev_info->is_shared == 0)) {
PRINT_WARN("Segment %s already loaded in exclusive mode!\n",
dev_info->segment_name);
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
return count;
}
if (inbuf[0] == '1') {
@@ -231,7 +205,7 @@
PRINT_INFO("Segment %s reloaded, exclusive (read-write) mode.\n",
dev_info->segment_name);
} else {
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
PRINT_WARN("Invalid value, must be 0 or 1\n");
return -EINVAL;
}
@@ -262,14 +236,13 @@
dev_info->segment_name);
rc = -EPERM;
}
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
goto out;

removeseg:
PRINT_ERR("Could not reload segment %s, removing it now!\n",
dev_info->segment_name);
list_del(&dev_info->lh);
- write_unlock(&dcssblk_devices_lock);

del_gendisk(dev_info->gd);
blk_put_queue(dev_info->dcssblk_queue);
@@ -277,6 +250,7 @@
put_disk(dev_info->gd);
device_unregister(dev);
put_device(dev);
+ up_write(&dcssblk_devices_sem);
out:
return rc;
}
@@ -308,7 +282,7 @@
}
dev_info = container_of(dev, struct dcssblk_dev_info, dev);

- write_lock(&dcssblk_devices_lock);
+ down_write(&dcssblk_devices_sem);
if (inbuf[0] == '1') {
if (atomic_read(&dev_info->use_count) == 0) {
// device is idle => we save immediately
@@ -332,11 +306,11 @@
dev_info->segment_name);
}
} else {
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
PRINT_WARN("Invalid value, must be 0 or 1\n");
return -EINVAL;
}
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
return count;
}

@@ -375,9 +349,9 @@
/*
* already loaded?
*/
- read_lock(&dcssblk_devices_lock);
+ down_read(&dcssblk_devices_sem);
dev_info = dcssblk_get_device_by_name(local_buf);
- read_unlock(&dcssblk_devices_lock);
+ up_read(&dcssblk_devices_sem);
if (dev_info != NULL) {
PRINT_WARN("Segment %s already loaded!\n", local_buf);
rc = -EEXIST;
@@ -433,10 +407,10 @@
/*
* get minor, add to list
*/
- write_lock(&dcssblk_devices_lock);
+ down_write(&dcssblk_devices_sem);
rc = dcssblk_assign_free_minor(dev_info);
if (rc) {
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
PRINT_ERR("No free minor number available! "
"Unloading segment...\n");
goto unload_seg;
@@ -444,22 +418,29 @@
sprintf(dev_info->gd->disk_name, "dcssblk%d",
dev_info->gd->first_minor);
list_add_tail(&dev_info->lh, &dcssblk_devices);
+
+ if (!try_module_get(THIS_MODULE)) {
+ rc = -ENODEV;
+ goto list_del;
+ }
/*
* register the device
*/
- rc = dcssblk_register_segment_device(&dev_info->dev);
+ rc = device_register(&dev_info->dev);
if (rc) {
PRINT_ERR("Segment %s could not be registered RC=%d\n",
local_buf, rc);
+ module_put(THIS_MODULE);
goto list_del;
}
-
- if (!try_module_get(THIS_MODULE)) {
- rc = -ENODEV;
- goto list_del;
- }
-
get_device(&dev_info->dev);
+ rc = device_create_file(&dev_info->dev, &dev_attr_shared);
+ if (rc)
+ goto unregister_dev;
+ rc = device_create_file(&dev_info->dev, &dev_attr_save);
+ if (rc)
+ goto unregister_dev;
+
add_disk(dev_info->gd);

blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
@@ -476,13 +457,24 @@
break;
}
PRINT_DEBUG("Segment %s loaded successfully\n", local_buf);
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
rc = count;
goto out;

+unregister_dev:
+ PRINT_ERR("device_create_file() failed!\n");
+ list_del(&dev_info->lh);
+ blk_put_queue(dev_info->dcssblk_queue);
+ dev_info->gd->queue = NULL;
+ put_disk(dev_info->gd);
+ device_unregister(&dev_info->dev);
+ segment_unload(dev_info->segment_name);
+ put_device(&dev_info->dev);
+ up_write(&dcssblk_devices_sem);
+ goto out;
list_del:
list_del(&dev_info->lh);
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
unload_seg:
segment_unload(local_buf);
dealloc_gendisk:
@@ -526,22 +518,21 @@
goto out_buf;
}

- write_lock(&dcssblk_devices_lock);
+ down_write(&dcssblk_devices_sem);
dev_info = dcssblk_get_device_by_name(local_buf);
if (dev_info == NULL) {
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
PRINT_WARN("Segment %s is not loaded!\n", local_buf);
rc = -ENODEV;
goto out_buf;
}
if (atomic_read(&dev_info->use_count) != 0) {
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
PRINT_WARN("Segment %s is in use!\n", local_buf);
rc = -EBUSY;
goto out_buf;
}
list_del(&dev_info->lh);
- write_unlock(&dcssblk_devices_lock);

del_gendisk(dev_info->gd);
blk_put_queue(dev_info->dcssblk_queue);
@@ -552,6 +543,8 @@
PRINT_DEBUG("Segment %s unloaded successfully\n",
dev_info->segment_name);
put_device(&dev_info->dev);
+ up_write(&dcssblk_devices_sem);
+
rc = count;
out_buf:
kfree(local_buf);
@@ -587,7 +580,7 @@
rc = -ENODEV;
goto out;
}
- write_lock(&dcssblk_devices_lock);
+ down_write(&dcssblk_devices_sem);
if (atomic_dec_and_test(&dev_info->use_count)
&& (dev_info->save_pending)) {
PRINT_INFO("Segment %s became idle and is being saved now\n",
@@ -595,7 +588,7 @@
segment_replace(dev_info->segment_name);
dev_info->save_pending = 0;
}
- write_unlock(&dcssblk_devices_lock);
+ up_write(&dcssblk_devices_sem);
rc = 0;
out:
return rc;
@@ -616,7 +609,7 @@
dev_info = bio->bi_bdev->bd_disk->private_data;
if (dev_info == NULL)
goto fail;
- if ((bio->bi_sector & 3) != 0 || (bio->bi_size & 4095) != 0)
+ if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
/* Request is not page-aligned. */
goto fail;
if (((bio->bi_size >> 9) + bio->bi_sector)
@@ -695,6 +688,7 @@
return rc;
}
dcssblk_major = rc;
+ init_rwsem(&dcssblk_devices_sem);
PRINT_DEBUG("...finished!\n");
return 0;
}
diff -urN linux-2.6/drivers/s390/block/xpram.c linux-2.6-s390/drivers/s390/block/xpram.c
--- linux-2.6/drivers/s390/block/xpram.c Mon May 10 04:32:54 2004
+++ linux-2.6-s390/drivers/s390/block/xpram.c Wed Jun 2 11:29:39 2004
@@ -290,7 +290,7 @@
unsigned long bytes;
int i;

- if ((bio->bi_sector & 3) != 0 || (bio->bi_size & 4095) != 0)
+ if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
/* Request is not page-aligned. */
goto fail;
if ((bio->bi_size >> 12) > xdev->size)
-
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