From d9a9cdfb078d755e648d53ec25b7370f84ee5729 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 15 Mar 2007 15:50:34 -0400 Subject: [PATCH] sysfs and driver core: add callback helper, used by SCSI and S390 This patch (as868) adds a helper routine for device drivers that need to set up a callback to perform some action in a different process's context. This is intended for use by attribute methods that want to unregister themselves or their parent device. Attribute method calls are mutually exclusive with unregistration, so such actions cannot be taken directly. Two attribute methods are converted to use the new helper routine: one for SCSI device deletion and one for System/390 ccwgroup devices. Signed-off-by: Alan Stern Cc: Hugh Dickins Cc: Cornelia Huck Cc: Oliver Neukum Signed-off-by: Linus Torvalds --- drivers/s390/cio/ccwgroup.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index d48e3ca4752..5aeb68e732b 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -71,19 +71,31 @@ __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev) * Provide an 'ungroup' attribute so the user can remove group devices no * longer needed or accidentially created. Saves memory :) */ +static void ccwgroup_ungroup_callback(struct device *dev) +{ + struct ccwgroup_device *gdev = to_ccwgroupdev(dev); + + __ccwgroup_remove_symlinks(gdev); + device_unregister(dev); +} + static ssize_t ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ccwgroup_device *gdev; + int rc; gdev = to_ccwgroupdev(dev); if (gdev->state != CCWGROUP_OFFLINE) return -EINVAL; - __ccwgroup_remove_symlinks(gdev); - device_unregister(dev); - + /* Note that we cannot unregister the device from one of its + * attribute methods, so we have to use this roundabout approach. + */ + rc = device_schedule_callback(dev, ccwgroup_ungroup_callback); + if (rc) + count = rc; return count; } -- cgit v1.2.3