diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 566d9f94f735..9a56e3adf476 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -73,7 +73,7 @@ set_bConfigurationValue(struct device *dev, struct device_attribute *attr, return (value < 0) ? value : count; } -static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR, +static DEVICE_ATTR_IGNORE_LOCKDEP(bConfigurationValue, S_IRUGO | S_IWUSR, show_bConfigurationValue, set_bConfigurationValue); /* String fields */ @@ -595,7 +595,7 @@ static ssize_t usb_dev_authorized_store(struct device *dev, return result < 0? result : size; } -static DEVICE_ATTR(authorized, 0644, +static DEVICE_ATTR_IGNORE_LOCKDEP(authorized, 0644, usb_dev_authorized_show, usb_dev_authorized_store); /* "Safely remove a device" */ @@ -618,7 +618,7 @@ static ssize_t usb_remove_store(struct device *dev, usb_unlock_device(udev); return rc; } -static DEVICE_ATTR(remove, 0200, NULL, usb_remove_store); +static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0200, NULL, usb_remove_store); static struct attribute *dev_attrs[] = { diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 24fa995f0312..e6bb9b2a4cbe 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -132,6 +132,24 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children); } +#ifdef CONFIG_DEBUG_LOCK_ALLOC + +/* Test for attributes that want to ignore lockdep for read-locking */ +static bool ignore_lockdep(struct sysfs_dirent *sd) +{ + return sysfs_type(sd) == SYSFS_KOBJ_ATTR && + sd->s_attr.attr->ignore_lockdep; +} + +#else + +static inline bool ignore_lockdep(struct sysfs_dirent *sd) +{ + return true; +} + +#endif + /** * sysfs_get_active - get an active reference to sysfs_dirent * @sd: sysfs_dirent to get an active reference to @@ -155,15 +173,17 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) return NULL; t = atomic_cmpxchg(&sd->s_active, v, v + 1); - if (likely(t == v)) { - rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); - return sd; - } + if (likely(t == v)) + break; if (t < 0) return NULL; cpu_relax(); } + + if (likely(!ignore_lockdep(sd))) + rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); + return sd; } /** @@ -180,7 +200,8 @@ void sysfs_put_active(struct sysfs_dirent *sd) if (unlikely(!sd)) return; - rwsem_release(&sd->dep_map, 1, _RET_IP_); + if (likely(!ignore_lockdep(sd))) + rwsem_release(&sd->dep_map, 1, _RET_IP_); v = atomic_dec_return(&sd->s_active); if (likely(v != SD_DEACTIVATED_BIAS)) return; diff --git a/include/linux/device.h b/include/linux/device.h index a8db2cfa2c81..e04f5776f6d0 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -504,6 +504,9 @@ ssize_t device_store_int(struct device *dev, struct device_attribute *attr, #define DEVICE_INT_ATTR(_name, _mode, _var) \ struct dev_ext_attribute dev_attr_##_name = \ { __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) } +#define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \ + struct device_attribute dev_attr_##_name = \ + __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) extern int device_create_file(struct device *device, const struct device_attribute *entry); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 0010009b2f00..381f06db2fe5 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -27,6 +27,7 @@ struct attribute { const char *name; umode_t mode; #ifdef CONFIG_DEBUG_LOCK_ALLOC + bool ignore_lockdep:1; struct lock_class_key *key; struct lock_class_key skey; #endif @@ -80,6 +81,17 @@ struct attribute_group { #define __ATTR_NULL { .attr = { .name = NULL } } +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) { \ + .attr = {.name = __stringify(_name), .mode = _mode, \ + .ignore_lockdep = true }, \ + .show = _show, \ + .store = _store, \ +} +#else +#define __ATTR_IGNORE_LOCKDEP __ATTR +#endif + #define attr_name(_attr) (_attr).attr.name struct file;