From ff483d55ba6fb50a8d6f99e808da35218533b1ef Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 13 Jan 2014 13:55:05 -0800 Subject: [PATCH] Revert "s390: use device_remove_file_self() instead of device_schedule_callback()" This reverts commit bdbb0a1376635d80e096f6433595a38984cf5408. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/s390/include/asm/ccwgroup.h | 1 - arch/s390/pci/pci_sysfs.c | 18 ++++++++++-------- drivers/s390/block/dcssblk.c | 14 +++++++------- drivers/s390/cio/ccwgroup.c | 26 ++++++++++---------------- 4 files changed, 27 insertions(+), 32 deletions(-) diff --git a/arch/s390/include/asm/ccwgroup.h b/arch/s390/include/asm/ccwgroup.h index 6e670f88d125..23723ce5ca7a 100644 --- a/arch/s390/include/asm/ccwgroup.h +++ b/arch/s390/include/asm/ccwgroup.h @@ -23,7 +23,6 @@ struct ccwgroup_device { unsigned int count; struct device dev; struct ccw_device *cdev[0]; - struct work_struct ungroup_work; }; /** diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c index ab4a91393005..cf8a12ff733b 100644 --- a/arch/s390/pci/pci_sysfs.c +++ b/arch/s390/pci/pci_sysfs.c @@ -48,27 +48,29 @@ static ssize_t show_pfgid(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(pfgid, S_IRUGO, show_pfgid, NULL); -static ssize_t store_recover(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +static void recover_callback(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); struct zpci_dev *zdev = get_zdev(pdev); int ret; - if (!device_remove_file_self(dev, attr)) - return count; - pci_stop_and_remove_bus_device(pdev); ret = zpci_disable_device(zdev); if (ret) - return ret; + return; ret = zpci_enable_device(zdev); if (ret) - return ret; + return; pci_rescan_bus(zdev->bus); - return count; +} + +static ssize_t store_recover(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + int rc = device_schedule_callback(dev, recover_callback); + return rc ? rc : count; } static DEVICE_ATTR(recover, S_IWUSR, NULL, store_recover); diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 2e2f454a05a1..6eca019bcf30 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -304,6 +304,12 @@ dcssblk_load_segment(char *name, struct segment_info **seg_info) return rc; } +static void dcssblk_unregister_callback(struct device *dev) +{ + device_unregister(dev); + put_device(dev); +} + /* * device attribute for switching shared/nonshared (exclusive) * operation (show + store) @@ -391,13 +397,7 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch blk_cleanup_queue(dev_info->dcssblk_queue); dev_info->gd->queue = NULL; put_disk(dev_info->gd); - up_write(&dcssblk_devices_sem); - - if (device_remove_file_self(dev, attr)) { - device_unregister(dev); - put_device(dev); - } - return rc; + rc = device_schedule_callback(dev, dcssblk_unregister_callback); out: up_write(&dcssblk_devices_sem); return rc; diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 67b9dc9044c2..959135a01847 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -168,12 +168,14 @@ static ssize_t ccwgroup_online_show(struct device *dev, * Provide an 'ungroup' attribute so the user can remove group devices no * longer needed or accidentially created. Saves memory :) */ -static void ccwgroup_ungroup(struct ccwgroup_device *gdev) +static void ccwgroup_ungroup_callback(struct device *dev) { + struct ccwgroup_device *gdev = to_ccwgroupdev(dev); + mutex_lock(&gdev->reg_mutex); if (device_is_registered(&gdev->dev)) { __ccwgroup_remove_symlinks(gdev); - device_unregister(&gdev->dev); + device_unregister(dev); __ccwgroup_remove_cdev_refs(gdev); } mutex_unlock(&gdev->reg_mutex); @@ -193,9 +195,10 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev, rc = -EINVAL; goto out; } - - if (device_remove_file_self(dev, attr)) - ccwgroup_ungroup(gdev); + /* 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); out: if (rc) { if (rc != -EAGAIN) @@ -221,14 +224,6 @@ static const struct attribute_group *ccwgroup_attr_groups[] = { NULL, }; -static void ccwgroup_ungroup_workfn(struct work_struct *work) -{ - struct ccwgroup_device *gdev = - container_of(work, struct ccwgroup_device, ungroup_work); - - ccwgroup_ungroup(gdev); -} - static void ccwgroup_release(struct device *dev) { kfree(to_ccwgroupdev(dev)); @@ -328,7 +323,6 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv, atomic_set(&gdev->onoff, 0); mutex_init(&gdev->reg_mutex); mutex_lock(&gdev->reg_mutex); - INIT_WORK(&gdev->ungroup_work, ccwgroup_ungroup_workfn); gdev->count = num_devices; gdev->dev.bus = &ccwgroup_bus_type; gdev->dev.parent = parent; @@ -410,10 +404,10 @@ EXPORT_SYMBOL(ccwgroup_create_dev); static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action, void *data) { - struct ccwgroup_device *gdev = to_ccwgroupdev(data); + struct device *dev = data; if (action == BUS_NOTIFY_UNBIND_DRIVER) - schedule_work(&gdev->ungroup_work); + device_schedule_callback(dev, ccwgroup_ungroup_callback); return NOTIFY_OK; }