s390/dasd: Add 'timeout' attribute

This patch adds a 'timeout' attibute to the DASD driver.
When set to non-zero, the blk_timeout function will
be enabled with the timeout specified in the attribute.
Setting 'timeout' to '0' will disable block timeouts.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Hannes Reinecke 2013-01-30 09:26:18 +00:00 committed by Martin Schwidefsky
parent 80bd7181b0
commit 3d71ad3216
3 changed files with 62 additions and 0 deletions

View File

@ -2894,6 +2894,8 @@ enum blk_eh_timer_return dasd_times_out(struct request *req)
return BLK_EH_NOT_HANDLED;
device = cqr->startdev ? cqr->startdev : block->base;
if (!device->blk_timeout)
return BLK_EH_RESET_TIMER;
DBF_DEV_EVENT(DBF_WARNING, device,
" dasd_times_out cqr %p status %x",
cqr, cqr->status);

View File

@ -1280,6 +1280,61 @@ dasd_retries_store(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR(retries, 0644, dasd_retries_show, dasd_retries_store);
static ssize_t
dasd_timeout_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct dasd_device *device;
int len;
device = dasd_device_from_cdev(to_ccwdev(dev));
if (IS_ERR(device))
return -ENODEV;
len = snprintf(buf, PAGE_SIZE, "%lu\n", device->blk_timeout);
dasd_put_device(device);
return len;
}
static ssize_t
dasd_timeout_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct dasd_device *device;
struct request_queue *q;
unsigned long val, flags;
device = dasd_device_from_cdev(to_ccwdev(dev));
if (IS_ERR(device) || !device->block)
return -ENODEV;
if ((strict_strtoul(buf, 10, &val) != 0) ||
val > UINT_MAX / HZ) {
dasd_put_device(device);
return -EINVAL;
}
q = device->block->request_queue;
if (!q) {
dasd_put_device(device);
return -ENODEV;
}
spin_lock_irqsave(&device->block->request_queue_lock, flags);
if (!val)
blk_queue_rq_timed_out(q, NULL);
else
blk_queue_rq_timed_out(q, dasd_times_out);
device->blk_timeout = val;
blk_queue_rq_timeout(q, device->blk_timeout * HZ);
spin_unlock_irqrestore(&device->block->request_queue_lock, flags);
dasd_put_device(device);
return count;
}
static DEVICE_ATTR(timeout, 0644,
dasd_timeout_show, dasd_timeout_store);
static ssize_t dasd_reservation_policy_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@ -1391,6 +1446,7 @@ static struct attribute * dasd_attrs[] = {
&dev_attr_failfast.attr,
&dev_attr_expires.attr,
&dev_attr_retries.attr,
&dev_attr_timeout.attr,
&dev_attr_reservation_policy.attr,
&dev_attr_last_known_reservation_state.attr,
&dev_attr_safe_offline.attr,

View File

@ -470,6 +470,8 @@ struct dasd_device {
unsigned long default_expires;
unsigned long default_retries;
unsigned long blk_timeout;
struct dentry *debugfs_dentry;
struct dasd_profile profile;
};
@ -663,6 +665,8 @@ void dasd_free_device(struct dasd_device *);
struct dasd_block *dasd_alloc_block(void);
void dasd_free_block(struct dasd_block *);
enum blk_eh_timer_return dasd_times_out(struct request *req);
void dasd_enable_device(struct dasd_device *);
void dasd_set_target_state(struct dasd_device *, int);
void dasd_kick_device(struct dasd_device *);