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path: root/drivers/scsi/ch.c
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Diffstat (limited to 'drivers/scsi/ch.c')
-rw-r--r--drivers/scsi/ch.c40
1 files changed, 28 insertions, 12 deletions
diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index ed5f4a6ae270..cb74ab1ae5a4 100644
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -44,7 +44,6 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
-static DEFINE_MUTEX(ch_mutex);
static int init = 1;
module_param(init, int, 0444);
MODULE_PARM_DESC(init, \
@@ -569,6 +568,7 @@ static void ch_destroy(struct kref *ref)
{
scsi_changer *ch = container_of(ref, scsi_changer, ref);
+ ch->device = NULL;
kfree(ch->dt);
kfree(ch);
}
@@ -590,20 +590,22 @@ ch_open(struct inode *inode, struct file *file)
scsi_changer *ch;
int minor = iminor(inode);
- mutex_lock(&ch_mutex);
spin_lock(&ch_index_lock);
ch = idr_find(&ch_index_idr, minor);
- if (NULL == ch || scsi_device_get(ch->device)) {
+ if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
spin_unlock(&ch_index_lock);
- mutex_unlock(&ch_mutex);
return -ENXIO;
}
- kref_get(&ch->ref);
spin_unlock(&ch_index_lock);
-
+ if (scsi_device_get(ch->device)) {
+ kref_put(&ch->ref, ch_destroy);
+ return -ENXIO;
+ }
+ /* Synchronize with ch_probe() */
+ mutex_lock(&ch->lock);
file->private_data = ch;
- mutex_unlock(&ch_mutex);
+ mutex_unlock(&ch->lock);
return 0;
}
@@ -938,7 +940,16 @@ static int ch_probe(struct device *dev)
ch->minor = ret;
sprintf(ch->name,"ch%d",ch->minor);
+ ret = scsi_device_get(sd);
+ if (ret) {
+ sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
+ ch->minor);
+ goto remove_idr;
+ }
+ mutex_init(&ch->lock);
+ kref_init(&ch->ref);
+ ch->device = sd;
class_dev = device_create(ch_sysfs_class, dev,
MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
"s%s", ch->name);
@@ -946,24 +957,27 @@ static int ch_probe(struct device *dev)
sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
ch->minor);
ret = PTR_ERR(class_dev);
- goto remove_idr;
+ goto put_device;
}
- mutex_init(&ch->lock);
- kref_init(&ch->ref);
- ch->device = sd;
+ mutex_lock(&ch->lock);
ret = ch_readconfig(ch);
- if (ret)
+ if (ret) {
+ mutex_unlock(&ch->lock);
goto destroy_dev;
+ }
if (init)
ch_init_elem(ch);
+ mutex_unlock(&ch->lock);
dev_set_drvdata(dev, ch);
sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
return 0;
destroy_dev:
device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
+put_device:
+ scsi_device_put(sd);
remove_idr:
idr_remove(&ch_index_idr, ch->minor);
free_ch:
@@ -977,9 +991,11 @@ static int ch_remove(struct device *dev)
spin_lock(&ch_index_lock);
idr_remove(&ch_index_idr, ch->minor);
+ dev_set_drvdata(dev, NULL);
spin_unlock(&ch_index_lock);
device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
+ scsi_device_put(ch->device);
kref_put(&ch->ref, ch_destroy);
return 0;
}