[PATCH] s390: block device driver

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

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.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 9d30ebf0ba04c75ebc811c8c56a3710a73d11af5..6997d61dcc67834374503db84bc7268d0317c900 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -7,7 +7,7 @@
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (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@de.ibm.com>");
 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
@@ -1990,6 +1991,8 @@ dasd_init(void)
 
        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_init(dasd_init);
 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 --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index 67a896cd4f35d0015c67c06c6c7acc36a8dd8071..888aeb3998ed2471b12dd746a846747834f355ae 100644 (file)
--- a/drivers/s390/block/dasd_diag.c
+++ b/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: 1.34 $
+ * $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 @@ dasd_diag_check_device(struct dasd_device *device)
                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 @@ dasd_diag_init(void)
 
        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 @@ dasd_diag_cleanup(void)
        }
        unregister_external_interrupt(0x2603, dasd_ext_handler);
        ctl_clear_bit(0, 9);
+       dasd_diag_discipline_pointer = NULL;
 }
 
 module_init(dasd_diag_init);

diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 9967c082c0ada52996035a5bd9d58c1b3067ffad..b222f9503c1fc94fe092ebb913740227806cff55 100644 (file)
--- a/drivers/s390/block/dasd_int.h
+++ b/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: 1.57 $
+ * $Revision: 1.58 $
  */
 
 #ifndef DASD_INT_H
@@ -260,12 +260,7 @@ struct dasd_discipline {
        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 --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 8a30b525002b2b020404575c26a4ca38eefbd27a..ca83f9b0a8c165f229cee42293daa90a304a8bbb 100644 (file)
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -76,8 +76,7 @@ struct dcssblk_dev_info {
 };
 
 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 @@ dcssblk_release_segment(struct device *dev)
 
 /*
  * 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 @@ dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
 /*
  * 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)
@@ -136,31 +135,6 @@ dcssblk_get_device_by_name(char *name)
        return NULL;
 }
 
-/*
- * 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 @@ dcssblk_shared_store(struct device *dev, const char *inbuf, size_t count)
                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 @@ dcssblk_shared_store(struct device *dev, const char *inbuf, size_t count)
                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 @@ dcssblk_shared_store(struct device *dev, const char *inbuf, size_t count)
                                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 @@ removeseg:
        put_disk(dev_info->gd);
        device_unregister(dev);
        put_device(dev);
+       up_write(&dcssblk_devices_sem);
 out:
        return rc;
 }
@@ -308,7 +282,7 @@ dcssblk_save_store(struct device *dev, const char *inbuf, size_t count)
        }
        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 @@ dcssblk_save_store(struct device *dev, const char *inbuf, size_t count)
                                        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 @@ dcssblk_add_store(struct device *dev, const char *buf, size_t count)
        /*
         * 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 @@ dcssblk_add_store(struct device *dev, const char *buf, size_t count)
        /*
         * 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 @@ dcssblk_add_store(struct device *dev, const char *buf, size_t count)
        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 @@ dcssblk_add_store(struct device *dev, const char *buf, size_t count)
                        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 @@ dcssblk_remove_store(struct device *dev, const char *buf, size_t count)
                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 @@ dcssblk_remove_store(struct device *dev, const char *buf, size_t count)
        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 @@ dcssblk_release(struct inode *inode, struct file *filp)
                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 @@ dcssblk_release(struct inode *inode, struct file *filp)
                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 @@ dcssblk_make_request(request_queue_t *q, struct bio *bio)
        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 @@ dcssblk_init(void)
                return rc;
        }
        dcssblk_major = rc;
+       init_rwsem(&dcssblk_devices_sem);
        PRINT_DEBUG("...finished!\n");
        return 0;
 }

diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
index 00885b09f170c85ff1f03f7578a6fa35bedeb642..33109cf02aea68e0dbed90bb1cee99f9a1fb9b36 100644 (file)
--- a/drivers/s390/block/xpram.c
+++ b/drivers/s390/block/xpram.c
@@ -290,7 +290,7 @@ static int xpram_make_request(request_queue_t *q, struct bio *bio)
        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)