[PATCH] s390: deadlock in dasd_devmap
Reintroduce a read-only copy of the devmap features in the device struct. This is necessary to solve a deadlock on the dasd_devmap_lock which is acquired by dasd_get_features called from the dasd tasklet. The current implementation of devmap doesn't allow to call any devmap function from interrupt or softirq context. Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Коммит
c6eb7b7703
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@ -7,7 +7,7 @@
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* Bugreports.to..: <Linux390@de.ibm.com>
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* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
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*
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* $Revision: 1.165 $
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* $Revision: 1.167 $
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*/
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#include <linux/config.h>
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@ -1131,17 +1131,13 @@ __dasd_process_blk_queue(struct dasd_device * device)
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request_queue_t *queue;
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struct request *req;
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struct dasd_ccw_req *cqr;
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int nr_queued, feature_ro;
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int nr_queued;
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queue = device->request_queue;
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/* No queue ? Then there is nothing to do. */
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if (queue == NULL)
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return;
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feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
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if (feature_ro < 0) /* no devmap */
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return;
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/*
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* We requeue request from the block device queue to the ccw
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* queue only in two states. In state DASD_STATE_READY the
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@ -1162,7 +1158,8 @@ __dasd_process_blk_queue(struct dasd_device * device)
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nr_queued < DASD_CHANQ_MAX_SIZE) {
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req = elv_next_request(queue);
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if (feature_ro && rq_data_dir(req) == WRITE) {
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if (device->features & DASD_FEATURE_READONLY &&
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rq_data_dir(req) == WRITE) {
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DBF_DEV_EVENT(DBF_ERR, device,
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"Rejecting write request %p",
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req);
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@ -1814,17 +1811,13 @@ dasd_generic_set_online (struct ccw_device *cdev,
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{
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struct dasd_device *device;
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int feature_diag, rc;
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int rc;
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device = dasd_create_device(cdev);
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if (IS_ERR(device))
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return PTR_ERR(device);
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feature_diag = dasd_get_feature(cdev, DASD_FEATURE_USEDIAG);
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if (feature_diag < 0)
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return feature_diag;
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if (feature_diag) {
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if (device->features & DASD_FEATURE_USEDIAG) {
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if (!dasd_diag_discipline_pointer) {
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printk (KERN_WARNING
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"dasd_generic couldn't online device %s "
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@ -11,7 +11,7 @@
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* functions may not be called from interrupt context. In particular
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* dasd_get_device is a no-no from interrupt context.
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*
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* $Revision: 1.40 $
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* $Revision: 1.43 $
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*/
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#include <linux/config.h>
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@ -513,6 +513,7 @@ dasd_create_device(struct ccw_device *cdev)
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if (!devmap->device) {
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devmap->device = device;
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device->devindex = devmap->devindex;
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device->features = devmap->features;
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get_device(&cdev->dev);
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device->cdev = cdev;
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rc = 0;
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@ -643,6 +644,8 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr, const char *buf
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devmap->features |= DASD_FEATURE_READONLY;
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else
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devmap->features &= ~DASD_FEATURE_READONLY;
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if (devmap->device)
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devmap->device->features = devmap->features;
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if (devmap->device && devmap->device->gdp)
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set_disk_ro(devmap->device->gdp, ro_flag);
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spin_unlock(&dasd_devmap_lock);
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@ -758,7 +761,8 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
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devmap->features |= feature;
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else
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devmap->features &= ~feature;
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if (devmap->device)
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devmap->device->features = devmap->features;
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spin_unlock(&dasd_devmap_lock);
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return 0;
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}
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@ -9,7 +9,7 @@
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*
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* gendisk related functions for the dasd driver.
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*
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* $Revision: 1.50 $
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* $Revision: 1.51 $
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*/
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#include <linux/config.h>
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@ -31,16 +31,12 @@ int
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dasd_gendisk_alloc(struct dasd_device *device)
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{
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struct gendisk *gdp;
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int len, feature_ro;
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int len;
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/* Make sure the minor for this device exists. */
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if (device->devindex >= DASD_PER_MAJOR)
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return -EBUSY;
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feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
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if (feature_ro < 0)
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return feature_ro;
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gdp = alloc_disk(1 << DASD_PARTN_BITS);
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if (!gdp)
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return -ENOMEM;
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@ -75,7 +71,7 @@ dasd_gendisk_alloc(struct dasd_device *device)
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sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id);
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if (feature_ro)
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if (device->features & DASD_FEATURE_READONLY)
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set_disk_ro(gdp, 1);
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gdp->private_data = device;
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gdp->queue = device->request_queue;
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@ -6,7 +6,7 @@
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* Bugreports.to..: <Linux390@de.ibm.com>
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* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
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*
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* $Revision: 1.64 $
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* $Revision: 1.65 $
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*/
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#ifndef DASD_INT_H
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@ -286,6 +286,7 @@ struct dasd_device {
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unsigned int bp_block; /* bytes per block */
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unsigned int s2b_shift; /* log2 (bp_block/512) */
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unsigned long flags; /* per device flags */
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unsigned short features; /* copy of devmap-features (read-only!) */
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/* Device discipline stuff. */
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struct dasd_discipline *discipline;
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@ -7,7 +7,7 @@
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* Bugreports.to..: <Linux390@de.ibm.com>
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* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
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*
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* $Revision: 1.45 $
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* $Revision: 1.47 $
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*
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* i/o controls for the dasd driver.
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*/
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@ -296,7 +296,6 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args)
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{
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struct dasd_device *device;
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struct format_data_t fdata;
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int feature_ro;
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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@ -308,10 +307,7 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args)
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if (device == NULL)
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return -ENODEV;
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feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
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if (feature_ro < 0)
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return feature_ro;
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if (feature_ro)
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if (device->features & DASD_FEATURE_READONLY)
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return -EROFS;
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if (copy_from_user(&fdata, (void __user *) args,
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sizeof (struct format_data_t)))
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@ -384,7 +380,7 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
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struct dasd_device *device;
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struct dasd_information2_t *dasd_info;
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unsigned long flags;
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int rc, feature_ro;
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int rc;
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struct ccw_device *cdev;
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device = bdev->bd_disk->private_data;
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@ -394,10 +390,6 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
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if (!device->discipline->fill_info)
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return -EINVAL;
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feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
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if (feature_ro < 0)
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return feature_ro;
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dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
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if (dasd_info == NULL)
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return -ENOMEM;
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@ -427,7 +419,8 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
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(dasd_check_blocksize(device->bp_block)))
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dasd_info->format = DASD_FORMAT_NONE;
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dasd_info->features |= feature_ro;
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dasd_info->features |=
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((device->features & DASD_FEATURE_READONLY) != 0);
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if (device->discipline)
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memcpy(dasd_info->type, device->discipline->name, 4);
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@ -9,7 +9,7 @@
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*
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* /proc interface for the dasd driver.
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*
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* $Revision: 1.32 $
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* $Revision: 1.33 $
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*/
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#include <linux/config.h>
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@ -55,7 +55,6 @@ dasd_devices_show(struct seq_file *m, void *v)
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{
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struct dasd_device *device;
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char *substr;
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int feature;
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device = dasd_device_from_devindex((unsigned long) v - 1);
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if (IS_ERR(device))
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@ -79,10 +78,7 @@ dasd_devices_show(struct seq_file *m, void *v)
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else
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seq_printf(m, " is ????????");
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/* Print devices features. */
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feature = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
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if (feature < 0)
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return 0;
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substr = feature ? "(ro)" : " ";
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substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
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seq_printf(m, "%4s: ", substr);
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/* Print device status information. */
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switch ((device != NULL) ? device->state : -1) {
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