On Sun, 2004-04-04 at 23:33, Patrick Mansfield wrote:
> How is unregister_cdrom(&cd->cdi) called if the device is not open?
OK, the attached does everything correctly (as I should have done at
first) by using a kobject to hold the compound references.
I've stressed this one nicely. Unfortunately, it's showing up a bug in
scsi_sysfs (hold device open, remove it and re-add it at the same HCTL
and you'll see an "error 1").
James
===== drivers/scsi/sr.c 1.103 vs edited =====
--- 1.103/drivers/scsi/sr.c Fri Apr 2 11:30:44 2004
+++ edited/drivers/scsi/sr.c Mon Apr 5 15:59:34 2004
@@ -113,6 +113,28 @@
.generic_packet = sr_packet,
};
+static void sr_kobject_release(struct kobject *kobj);
+
+static struct kobj_type scsi_cdrom_kobj_type = {
+ .release = sr_kobject_release,
+};
+
+/*
+ * The get and put routines for the struct scsi_cd. Note this entity
+ * has a scsi_device pointer and owns a reference to this.
+ */
+static inline int scsi_cd_get(struct scsi_cd *cd)
+{
+ if (!kobject_get(&cd->kobj))
+ return -ENODEV;
+ return 0;
+}
+
+static inline void scsi_cd_put(struct scsi_cd *cd)
+{
+ kobject_put(&cd->kobj);
+}
+
/*
* This function checks to see if the media has been changed in the
* CDROM drive. It is possible that we have already sensed a change,
@@ -424,8 +446,15 @@
static int sr_block_release(struct inode *inode, struct file *file)
{
+ int ret;
struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
- return cdrom_release(&cd->cdi, file);
+ ret = cdrom_release(&cd->cdi, file);
+ if(ret)
+ return ret;
+
+ scsi_cd_put(cd);
+
+ return 0;
}
static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
@@ -467,7 +496,7 @@
struct scsi_device *sdev = cd->device;
int retval;
- retval = scsi_device_get(sdev);
+ retval = scsi_cd_get(cd);
if (retval)
return retval;
@@ -489,7 +518,7 @@
return 0;
error_out:
- scsi_device_put(sdev);
+ scsi_cd_put(cd);
return retval;
}
@@ -500,7 +529,6 @@
if (cd->device->sector_size > 2048)
sr_set_blocklength(cd, 2048);
- scsi_device_put(cd->device);
}
static int sr_probe(struct device *dev)
@@ -514,12 +542,18 @@
if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
goto fail;
+ if ((err = scsi_device_get(sdev)) != 0)
+ goto fail_put_sdev;
+
error = -ENOMEM;
cd = kmalloc(sizeof(*cd), GFP_KERNEL);
if (!cd)
goto fail;
memset(cd, 0, sizeof(*cd));
+ kobject_init(&cd->kobj);
+ cd->kobj.ktype = &scsi_cdrom_kobj_type;
+
disk = alloc_disk(1);
if (!disk)
goto fail_free;
@@ -588,6 +622,8 @@
put_disk(disk);
fail_free:
kfree(cd);
+fail_put_sdev:
+ scsi_device_put(sdev);
fail:
return error;
}
@@ -863,19 +899,31 @@
return cgc->stat;
}
-static int sr_remove(struct device *dev)
+static void sr_kobject_release(struct kobject *kobj)
{
- struct scsi_cd *cd = dev_get_drvdata(dev);
-
- del_gendisk(cd->disk);
+ struct scsi_cd *cd = container_of(kobj, struct scsi_cd, kobj);
+ struct scsi_device *sdev = cd->device;
spin_lock(&sr_index_lock);
clear_bit(cd->disk->first_minor, sr_index_bits);
spin_unlock(&sr_index_lock);
- put_disk(cd->disk);
unregister_cdrom(&cd->cdi);
+
+ put_disk(cd->disk);
+
kfree(cd);
+
+ scsi_device_put(sdev);
+}
+
+static int sr_remove(struct device *dev)
+{
+ struct scsi_cd *cd = dev_get_drvdata(dev);
+
+ del_gendisk(cd->disk);
+
+ scsi_cd_put(cd);
return 0;
}
===== drivers/scsi/sr.h 1.10 vs edited =====
--- 1.10/drivers/scsi/sr.h Mon May 26 04:50:43 2003
+++ edited/drivers/scsi/sr.h Mon Apr 5 15:51:37 2004
@@ -36,6 +36,9 @@
unsigned readcd_known:1; /* drive supports READ_CD (0xbe) */
unsigned readcd_cdda:1; /* reading audio data using READ_CD */
struct cdrom_device_info cdi;
+ /* We hold gendisk and scsi_device references on probe and use
+ * the refs on this kobj to decide when to release them */
+ struct kobject kobj;
struct gendisk *disk;
} Scsi_CD;
-------------------------------------------------------
This SF.Net email is sponsored by: IBM Linux Tutorials
Free Linux tutorial presented by Daniel Robbins, President and CEO of
GenToo technologies. Learn everything from fundamentals to system
administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
