};
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.
/*
* 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
/*
* 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)
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)
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') {
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;
}
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);
put_disk(dev_info->gd);
device_unregister(dev);
put_device(dev);
+ up_write(&dcssblk_devices_sem);
out:
return rc;
}
}
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
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;
}
/*
* 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;
/*
* 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;
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);
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:
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);
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);
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",
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;
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)
return rc;
}
dcssblk_major = rc;
+ init_rwsem(&dcssblk_devices_sem);
PRINT_DEBUG("...finished!\n");
return 0;
}
git://git.onelab.eu / linux-2.6.git / blobdiff