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| author | Stefan Haberland <stefan.haberland@de.ibm.com> | 2016-03-18 09:42:13 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-04-15 18:16:37 +0200 |
| commit | 5a3b7b112884f80ff19b18028fabeb4f9c035518 (patch) | |
| tree | b1b743c481c829d26fdb97043f446f9f0d682b4f /drivers/s390/block/dasd_devmap.c | |
| parent | 2fd92273646abad21766ddfbfa00b6f927362308 (diff) | |
| download | linux-5a3b7b112884f80ff19b18028fabeb4f9c035518.tar.gz | |
s390/dasd: add query host access to volume support
With this feature, applications can query if a DASD volume is online
to another operating system instances by checking the online status of
all attached hosts from the storage server.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/block/dasd_devmap.c')
| -rw-r--r-- | drivers/s390/block/dasd_devmap.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index 2f18f61092b52a..3cdbce45e4649f 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -982,6 +982,32 @@ out: static DEVICE_ATTR(safe_offline, 0200, NULL, dasd_safe_offline_store); static ssize_t +dasd_access_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct ccw_device *cdev = to_ccwdev(dev); + struct dasd_device *device; + int count; + + device = dasd_device_from_cdev(cdev); + if (IS_ERR(device)) + return PTR_ERR(device); + + if (device->discipline->host_access_count) + count = device->discipline->host_access_count(device); + else + count = -EOPNOTSUPP; + + dasd_put_device(device); + if (count < 0) + return count; + + return sprintf(buf, "%d\n", count); +} + +static DEVICE_ATTR(host_access_count, 0444, dasd_access_show, NULL); + +static ssize_t dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1471,6 +1497,7 @@ static struct attribute * dasd_attrs[] = { &dev_attr_reservation_policy.attr, &dev_attr_last_known_reservation_state.attr, &dev_attr_safe_offline.attr, + &dev_attr_host_access_count.attr, &dev_attr_path_masks.attr, NULL, }; |