Re: [PATCH] Driver Core update for 2.6.4

Greg KH
2004-03-16T01:22:49Z

ChangeSet 1.1608.84.13, 2004/03/12 15:20:49-08:00, corbet@lwn.net

[PATCH] cdev 2/2: hide cdev->kobj

The existing cdev interface requires users to deal with the embedded
kobject in two places:

- The kobject name field must be set before adding the cdev, and
- Should cdev_add() fail, a call to kobject_put() is required.

IMO, this exposure of the embedded kobject makes the interface more brittle
and harder to understand. It's also unnecessary. With the removal of
/sys/cdev, a call to cdev_del() will nicely replace kobject_put(), and the
name setting is easily wrapped.

This is against 2.6.4, but depends on the /sys/cdev removal patch.

drivers/char/tty_io.c | 12 ++++++------
drivers/ieee1394/amdtp.c | 2 +-
drivers/ieee1394/dv1394.c | 2 +-
drivers/ieee1394/raw1394.c | 3 ++-
drivers/ieee1394/video1394.c | 2 +-
drivers/s390/char/tape_class.c | 4 ++--
drivers/scsi/sg.c | 4 ++--
drivers/scsi/st.c | 5 ++---
include/linux/cdev.h | 2 ++
9 files changed, 19 insertions(+), 17 deletions(-)

diff -Nru a/drivers/char/tty_io.c b/drivers/char/tty_io.c
--- a/drivers/char/tty_io.c Mon Mar 15 15:28:33 2004
+++ b/drivers/char/tty_io.c Mon Mar 15 15:28:33 2004
@@ -2274,14 +2274,14 @@
driver->termios_locked = NULL;
}

- strcpy(driver->cdev.kobj.name, driver->name);
+ cdev_set_name(&driver->cdev, driver->name);
for (s = strchr(driver->cdev.kobj.name, '/'); s; s = strchr(s, '/'))
*s = '!';
cdev_init(&driver->cdev, &tty_fops);
driver->cdev.owner = driver->owner;
error = cdev_add(&driver->cdev, dev, driver->num);
if (error) {
- kobject_del(&driver->cdev.kobj);
+ cdev_del(&driver->cdev);
unregister_chrdev_region(dev, driver->num);
driver->ttys = NULL;
driver->termios = driver->termios_locked = NULL;
@@ -2414,7 +2414,7 @@
*/
static int __init tty_init(void)
{
- strcpy(tty_cdev.kobj.name, "dev.tty");
+ cdev_set_name(&tty_cdev, "dev.tty");
cdev_init(&tty_cdev, &tty_fops);
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
@@ -2422,7 +2422,7 @@
devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");

- strcpy(console_cdev.kobj.name, "dev.console");
+ cdev_set_name(&console_cdev, "dev.console");
cdev_init(&console_cdev, &console_fops);
if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
@@ -2431,7 +2431,7 @@
class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");

#ifdef CONFIG_UNIX98_PTYS
- strcpy(ptmx_cdev.kobj.name, "dev.ptmx");
+ cdev_set_name(&ptmx_cdev, "dev.ptmx");
cdev_init(&ptmx_cdev, &tty_fops);
if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
@@ -2441,7 +2441,7 @@
#endif

#ifdef CONFIG_VT
- strcpy(vc0_cdev.kobj.name, "dev.vc0");
+ cdev_set_name(&vc0_cdev, "dev.vc0");
cdev_init(&vc0_cdev, &console_fops);
if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
diff -Nru a/drivers/ieee1394/amdtp.c b/drivers/ieee1394/amdtp.c
--- a/drivers/ieee1394/amdtp.c Mon Mar 15 15:28:33 2004
+++ b/drivers/ieee1394/amdtp.c Mon Mar 15 15:28:33 2004
@@ -1266,7 +1266,7 @@
{
cdev_init(&amdtp_cdev, &amdtp_fops);
amdtp_cdev.owner = THIS_MODULE;
- kobject_set_name(&amdtp_cdev.kobj, "amdtp");
+ cdev_set_name(&amdtp_cdev, "amdtp");
if (cdev_add(&amdtp_cdev, IEEE1394_AMDTP_DEV, 16)) {
HPSB_ERR("amdtp: unable to add char device");
return -EIO;
diff -Nru a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
--- a/drivers/ieee1394/dv1394.c Mon Mar 15 15:28:33 2004
+++ b/drivers/ieee1394/dv1394.c Mon Mar 15 15:28:33 2004
@@ -2616,7 +2616,7 @@

cdev_init(&dv1394_cdev, &dv1394_fops);
dv1394_cdev.owner = THIS_MODULE;
- kobject_set_name(&dv1394_cdev.kobj, "dv1394");
+ cdev_set_name(&dv1394_cdev, "dv1394");
ret = cdev_add(&dv1394_cdev, IEEE1394_DV1394_DEV, 16);
if (ret) {
printk(KERN_ERR "dv1394: unable to register character device\n");
diff -Nru a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c
--- a/drivers/ieee1394/raw1394.c Mon Mar 15 15:28:33 2004
+++ b/drivers/ieee1394/raw1394.c Mon Mar 15 15:28:33 2004
@@ -2746,9 +2746,10 @@

cdev_init(&raw1394_cdev, &raw1394_fops);
raw1394_cdev.owner = THIS_MODULE;
- kobject_set_name(&raw1394_cdev.kobj, RAW1394_DEVICE_NAME);
+ cdev_set_name(&raw1394_cdev, RAW1394_DEVICE_NAME);
ret = cdev_add(&raw1394_cdev, IEEE1394_RAW1394_DEV, 1);
if (ret) {
+ /* jmc: leaves reference to (static) raw1394_cdev */
HPSB_ERR("raw1394 failed to register minor device block");
devfs_remove(RAW1394_DEVICE_NAME);
hpsb_unregister_highlevel(&raw1394_highlevel);
diff -Nru a/drivers/ieee1394/video1394.c b/drivers/ieee1394/video1394.c
--- a/drivers/ieee1394/video1394.c Mon Mar 15 15:28:33 2004
+++ b/drivers/ieee1394/video1394.c Mon Mar 15 15:28:33 2004
@@ -1457,7 +1457,7 @@

cdev_init(&video1394_cdev, &video1394_fops);
video1394_cdev.owner = THIS_MODULE;
- kobject_set_name(&video1394_cdev.kobj, VIDEO1394_DRIVER_NAME);
+ cdev_set_name(&video1394_cdev, VIDEO1394_DRIVER_NAME);
ret = cdev_add(&video1394_cdev, IEEE1394_VIDEO1394_DEV, 16);
if (ret) {
PRINT_G(KERN_ERR, "video1394: unable to get minor device block");
diff -Nru a/drivers/s390/char/tape_class.c b/drivers/s390/char/tape_class.c
--- a/drivers/s390/char/tape_class.c Mon Mar 15 15:28:33 2004
+++ b/drivers/s390/char/tape_class.c Mon Mar 15 15:28:33 2004
@@ -46,13 +46,13 @@
cdev->owner = fops->owner;
cdev->ops = fops;
cdev->dev = dev;
- strcpy(cdev->kobj.name, devname);
+ cdev_set_name(cdev, devname);
for (s = strchr(cdev->kobj.name, '/'); s; s = strchr(s, '/'))
*s = '!';

rc = cdev_add(cdev, cdev->dev, 1);
if (rc) {
- kobject_put(&cdev->kobj);
+ cdev_del(cdev);
return ERR_PTR(rc);
}
class_simple_device_add(tape_class, cdev->dev, device, "%s", devname);
diff -Nru a/drivers/scsi/sg.c b/drivers/scsi/sg.c
--- a/drivers/scsi/sg.c Mon Mar 15 15:28:33 2004
+++ b/drivers/scsi/sg.c Mon Mar 15 15:28:33 2004
@@ -1409,7 +1409,7 @@
SCSI_LOG_TIMEOUT(3, printk("sg_add: dev=%d \n", k));
memset(sdp, 0, sizeof(*sdp));
sprintf(disk->disk_name, "sg%d", k);
- strncpy(cdev->kobj.name, disk->disk_name, KOBJ_NAME_LEN);
+ cdev_set_name(cdev, disk->disk_name);
cdev->owner = THIS_MODULE;
cdev->ops = &sg_fops;
disk->major = SCSI_GENERIC_MAJOR;
@@ -1462,7 +1462,7 @@
out:
put_disk(disk);
if (cdev)
- kobject_put(&cdev->kobj);
+ cdev_del(cdev);
return error;
}

diff -Nru a/drivers/scsi/st.c b/drivers/scsi/st.c
--- a/drivers/scsi/st.c Mon Mar 15 15:28:33 2004
+++ b/drivers/scsi/st.c Mon Mar 15 15:28:33 2004
@@ -3888,8 +3888,7 @@
dev_num);
goto out_free_tape;
}
- snprintf(cdev->kobj.name, KOBJ_NAME_LEN, "%sm%d%s", disk->disk_name,
- mode, j ? "n" : "");
+ cdev_set_name(cdev, "%sm%d%s", disk->disk_name, mode, j ? "n" : "");
cdev->owner = THIS_MODULE;
cdev->ops = &st_fops;

@@ -3944,7 +3943,7 @@
}
}
if (cdev)
- kobject_put(&cdev->kobj);
+ cdev_del(cdev);
write_lock(&st_dev_arr_lock);
scsi_tapes[dev_num] = NULL;
st_nr_dev--;
diff -Nru a/include/linux/cdev.h b/include/linux/cdev.h
--- a/include/linux/cdev.h Mon Mar 15 15:28:33 2004
+++ b/include/linux/cdev.h Mon Mar 15 15:28:33 2004
@@ -25,5 +25,7 @@

void cd_forget(struct inode *);

+#define cdev_set_name(cdev, args...) kobject_set_name(&((cdev)->kobj), ##args)
+
#endif
#endif