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authorHorst Hummel <horst.hummel@de.ibm.com>2005-09-03 15:57:58 -0700
committerLinus Torvalds <torvalds@evo.osdl.org>2005-09-05 00:06:26 -0700
commitc6eb7b7703ac4b3401b74f411c8c51ded214bf19 (patch)
tree1cb3563cb83f80347dbc3e4bd30c4635d401e87a /drivers/s390
parent942eaabd5d77522223a311ed9bddaaa3cefde27d (diff)
[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>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/block/dasd.c19
-rw-r--r--drivers/s390/block/dasd_devmap.c8
-rw-r--r--drivers/s390/block/dasd_genhd.c10
-rw-r--r--drivers/s390/block/dasd_int.h3
-rw-r--r--drivers/s390/block/dasd_ioctl.c17
-rw-r--r--drivers/s390/block/dasd_proc.c8
6 files changed, 24 insertions, 41 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index d5f53980749b..8fc891a9d47f 100644
--- 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: 1.165 $
+ * $Revision: 1.167 $
*/
#include <linux/config.h>
@@ -1131,17 +1131,13 @@ __dasd_process_blk_queue(struct dasd_device * device)
request_queue_t *queue;
struct request *req;
struct dasd_ccw_req *cqr;
- int nr_queued, feature_ro;
+ int nr_queued;
queue = device->request_queue;
/* No queue ? Then there is nothing to do. */
if (queue == NULL)
return;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0) /* no devmap */
- return;
-
/*
* We requeue request from the block device queue to the ccw
* queue only in two states. In state DASD_STATE_READY the
@@ -1162,7 +1158,8 @@ __dasd_process_blk_queue(struct dasd_device * device)
nr_queued < DASD_CHANQ_MAX_SIZE) {
req = elv_next_request(queue);
- if (feature_ro && rq_data_dir(req) == WRITE) {
+ if (device->features & DASD_FEATURE_READONLY &&
+ rq_data_dir(req) == WRITE) {
DBF_DEV_EVENT(DBF_ERR, device,
"Rejecting write request %p",
req);
@@ -1814,17 +1811,13 @@ dasd_generic_set_online (struct ccw_device *cdev,
{
struct dasd_device *device;
- int feature_diag, rc;
+ int rc;
device = dasd_create_device(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
- feature_diag = dasd_get_feature(cdev, DASD_FEATURE_USEDIAG);
- if (feature_diag < 0)
- return feature_diag;
-
- if (feature_diag) {
+ if (device->features & DASD_FEATURE_USEDIAG) {
if (!dasd_diag_discipline_pointer) {
printk (KERN_WARNING
"dasd_generic couldn't online device %s "
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index d948566bb24a..bda896d9d788 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -11,7 +11,7 @@
* functions may not be called from interrupt context. In particular
* dasd_get_device is a no-no from interrupt context.
*
- * $Revision: 1.40 $
+ * $Revision: 1.43 $
*/
#include <linux/config.h>
@@ -513,6 +513,7 @@ dasd_create_device(struct ccw_device *cdev)
if (!devmap->device) {
devmap->device = device;
device->devindex = devmap->devindex;
+ device->features = devmap->features;
get_device(&cdev->dev);
device->cdev = cdev;
rc = 0;
@@ -643,6 +644,8 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr, const char *buf
devmap->features |= DASD_FEATURE_READONLY;
else
devmap->features &= ~DASD_FEATURE_READONLY;
+ if (devmap->device)
+ devmap->device->features = devmap->features;
if (devmap->device && devmap->device->gdp)
set_disk_ro(devmap->device->gdp, ro_flag);
spin_unlock(&dasd_devmap_lock);
@@ -758,7 +761,8 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
devmap->features |= feature;
else
devmap->features &= ~feature;
-
+ if (devmap->device)
+ devmap->device->features = devmap->features;
spin_unlock(&dasd_devmap_lock);
return 0;
}
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index 96c49349701f..a601c9a33541 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -9,7 +9,7 @@
*
* gendisk related functions for the dasd driver.
*
- * $Revision: 1.50 $
+ * $Revision: 1.51 $
*/
#include <linux/config.h>
@@ -31,16 +31,12 @@ int
dasd_gendisk_alloc(struct dasd_device *device)
{
struct gendisk *gdp;
- int len, feature_ro;
+ int len;
/* Make sure the minor for this device exists. */
if (device->devindex >= DASD_PER_MAJOR)
return -EBUSY;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0)
- return feature_ro;
-
gdp = alloc_disk(1 << DASD_PARTN_BITS);
if (!gdp)
return -ENOMEM;
@@ -75,7 +71,7 @@ dasd_gendisk_alloc(struct dasd_device *device)
sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id);
- if (feature_ro)
+ if (device->features & DASD_FEATURE_READONLY)
set_disk_ro(gdp, 1);
gdp->private_data = device;
gdp->queue = device->request_queue;
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index a9f38b235981..9fab04f3056d 100644
--- 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: 1.64 $
+ * $Revision: 1.65 $
*/
#ifndef DASD_INT_H
@@ -286,6 +286,7 @@ struct dasd_device {
unsigned int bp_block; /* bytes per block */
unsigned int s2b_shift; /* log2 (bp_block/512) */
unsigned long flags; /* per device flags */
+ unsigned short features; /* copy of devmap-features (read-only!) */
/* Device discipline stuff. */
struct dasd_discipline *discipline;
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 980c555aa538..789595b3fa09 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -7,7 +7,7 @@
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
- * $Revision: 1.45 $
+ * $Revision: 1.47 $
*
* i/o controls for the dasd driver.
*/
@@ -296,7 +296,6 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args)
{
struct dasd_device *device;
struct format_data_t fdata;
- int feature_ro;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
@@ -308,10 +307,7 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args)
if (device == NULL)
return -ENODEV;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0)
- return feature_ro;
- if (feature_ro)
+ if (device->features & DASD_FEATURE_READONLY)
return -EROFS;
if (copy_from_user(&fdata, (void __user *) args,
sizeof (struct format_data_t)))
@@ -384,7 +380,7 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
struct dasd_device *device;
struct dasd_information2_t *dasd_info;
unsigned long flags;
- int rc, feature_ro;
+ int rc;
struct ccw_device *cdev;
device = bdev->bd_disk->private_data;
@@ -394,10 +390,6 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
if (!device->discipline->fill_info)
return -EINVAL;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0)
- return feature_ro;
-
dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
if (dasd_info == NULL)
return -ENOMEM;
@@ -427,7 +419,8 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args)
(dasd_check_blocksize(device->bp_block)))
dasd_info->format = DASD_FORMAT_NONE;
- dasd_info->features |= feature_ro;
+ dasd_info->features |=
+ ((device->features & DASD_FEATURE_READONLY) != 0);
if (device->discipline)
memcpy(dasd_info->type, device->discipline->name, 4);
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 43c34f8c5e68..fff9020d4886 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -9,7 +9,7 @@
*
* /proc interface for the dasd driver.
*
- * $Revision: 1.32 $
+ * $Revision: 1.33 $
*/
#include <linux/config.h>
@@ -55,7 +55,6 @@ dasd_devices_show(struct seq_file *m, void *v)
{
struct dasd_device *device;
char *substr;
- int feature;
device = dasd_device_from_devindex((unsigned long) v - 1);
if (IS_ERR(device))
@@ -79,10 +78,7 @@ dasd_devices_show(struct seq_file *m, void *v)
else
seq_printf(m, " is ????????");
/* Print devices features. */
- feature = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature < 0)
- return 0;
- substr = feature ? "(ro)" : " ";
+ substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
seq_printf(m, "%4s: ", substr);
/* Print device status information. */
switch ((device != NULL) ? device->state : -1) {