forked from Minki/linux
fsnotify: use a mutex instead of a spinlock to protect a groups mark list
Replaces the groups mark_lock spinlock with a mutex. Using a mutex instead of a spinlock results in more flexibility (i.e it allows to sleep while the lock is held). Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
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parent
6dfbd14994
commit
986ab09807
@ -95,7 +95,7 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
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init_waitqueue_head(&group->notification_waitq);
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group->max_events = UINT_MAX;
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spin_lock_init(&group->mark_lock);
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mutex_init(&group->mark_mutex);
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INIT_LIST_HEAD(&group->marks_list);
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group->ops = ops;
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@ -63,8 +63,8 @@ void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
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{
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struct inode *inode = mark->i.inode;
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BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
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assert_spin_locked(&mark->lock);
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assert_spin_locked(&mark->group->mark_lock);
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spin_lock(&inode->i_lock);
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@ -191,8 +191,8 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
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mark->flags |= FSNOTIFY_MARK_FLAG_INODE;
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BUG_ON(!mutex_is_locked(&group->mark_mutex));
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assert_spin_locked(&mark->lock);
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assert_spin_locked(&group->mark_lock);
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spin_lock(&inode->i_lock);
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@ -136,13 +136,13 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
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group = mark->group;
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spin_unlock(&mark->lock);
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spin_lock(&group->mark_lock);
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mutex_lock(&group->mark_mutex);
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spin_lock(&mark->lock);
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/* something else already called this function on this mark */
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if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) {
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spin_unlock(&mark->lock);
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spin_unlock(&group->mark_lock);
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mutex_unlock(&group->mark_mutex);
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goto put_group;
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}
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@ -159,7 +159,7 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark)
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list_del_init(&mark->g_list);
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spin_unlock(&mark->lock);
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spin_unlock(&group->mark_lock);
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mutex_unlock(&group->mark_mutex);
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spin_lock(&destroy_lock);
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list_add(&mark->destroy_list, &destroy_list);
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@ -232,11 +232,11 @@ int fsnotify_add_mark(struct fsnotify_mark *mark,
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/*
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* LOCKING ORDER!!!!
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* group->mark_lock
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* group->mark_mutex
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* mark->lock
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* inode->i_lock
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*/
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spin_lock(&group->mark_lock);
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mutex_lock(&group->mark_mutex);
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spin_lock(&mark->lock);
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mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE;
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@ -263,7 +263,7 @@ int fsnotify_add_mark(struct fsnotify_mark *mark,
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fsnotify_set_mark_mask_locked(mark, mark->mask);
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spin_unlock(&mark->lock);
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spin_unlock(&group->mark_lock);
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mutex_unlock(&group->mark_mutex);
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if (inode)
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__fsnotify_update_child_dentry_flags(inode);
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@ -277,7 +277,7 @@ err:
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atomic_dec(&group->num_marks);
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spin_unlock(&mark->lock);
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spin_unlock(&group->mark_lock);
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mutex_unlock(&group->mark_mutex);
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spin_lock(&destroy_lock);
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list_add(&mark->destroy_list, &destroy_list);
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@ -296,7 +296,7 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group,
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struct fsnotify_mark *lmark, *mark;
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LIST_HEAD(free_list);
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spin_lock(&group->mark_lock);
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mutex_lock(&group->mark_mutex);
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list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) {
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if (mark->flags & flags) {
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list_add(&mark->free_g_list, &free_list);
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@ -304,7 +304,7 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group,
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fsnotify_get_mark(mark);
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}
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}
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spin_unlock(&group->mark_lock);
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mutex_unlock(&group->mark_mutex);
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list_for_each_entry_safe(mark, lmark, &free_list, free_g_list) {
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fsnotify_destroy_mark(mark);
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@ -88,8 +88,8 @@ void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark)
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{
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struct vfsmount *mnt = mark->m.mnt;
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BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
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assert_spin_locked(&mark->lock);
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assert_spin_locked(&mark->group->mark_lock);
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spin_lock(&mnt->mnt_root->d_lock);
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@ -151,8 +151,8 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
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mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;
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BUG_ON(!mutex_is_locked(&group->mark_mutex));
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assert_spin_locked(&mark->lock);
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assert_spin_locked(&group->mark_lock);
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spin_lock(&mnt->mnt_root->d_lock);
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@ -141,7 +141,7 @@ struct fsnotify_group {
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unsigned int priority;
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/* stores all fastpath marks assoc with this group so they can be cleaned on unregister */
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spinlock_t mark_lock; /* protect marks_list */
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struct mutex mark_mutex; /* protect marks_list */
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atomic_t num_marks; /* 1 for each mark and 1 for not being
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* past the point of no return when freeing
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* a group */
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