fsnotify: unify inode and mount marks handling

There's a lot of common code in inode and mount marks handling.  Factor it
out to a common helper function.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 86 insertions, 3 deletions

diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 34c38fabf514..3942d5c9eb8d 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -110,6 +110,17 @@ void fsnotify_put_mark(struct fsnotify_mark *mark)
 	}
 }
 
+/* Calculate mask of events for a list of marks */
+u32 fsnotify_recalc_mask(struct hlist_head *head)
+{
+	u32 new_mask = 0;
+	struct fsnotify_mark *mark;
+
+	hlist_for_each_entry(mark, head, obj_list)
+		new_mask |= mark->mask;
+	return new_mask;
+}
+
 /*
  * Any time a mark is getting freed we end up here.
  * The caller had better be holding a reference to this mark so we don't actually
@@ -133,7 +144,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
 	mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE;
 
 	if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
-		inode = mark->i.inode;
+		inode = mark->inode;
 		fsnotify_destroy_inode_mark(mark);
 	} else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT)
 		fsnotify_destroy_vfsmount_mark(mark);
@@ -192,6 +203,27 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark,
 	mutex_unlock(&group->mark_mutex);
 }
 
+/*
+ * Destroy all marks in the given list. The marks must be already detached from
+ * the original inode / vfsmount.
+ */
+void fsnotify_destroy_marks(struct list_head *to_free)
+{
+	struct fsnotify_mark *mark, *lmark;
+	struct fsnotify_group *group;
+
+	list_for_each_entry_safe(mark, lmark, to_free, free_list) {
+		spin_lock(&mark->lock);
+		fsnotify_get_group(mark->group);
+		group = mark->group;
+		spin_unlock(&mark->lock);
+
+		fsnotify_destroy_mark(mark, group);
+		fsnotify_put_mark(mark);
+		fsnotify_put_group(group);
+	}
+}
+
 void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
 {
 	assert_spin_locked(&mark->lock);
@@ -245,6 +277,39 @@ int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b)
 	return -1;
 }
 
+/* Add mark into proper place in given list of marks */
+int fsnotify_add_mark_list(struct hlist_head *head, struct fsnotify_mark *mark,
+			   int allow_dups)
+{
+	struct fsnotify_mark *lmark, *last = NULL;
+	int cmp;
+
+	/* is mark the first mark? */
+	if (hlist_empty(head)) {
+		hlist_add_head_rcu(&mark->obj_list, head);
+		return 0;
+	}
+
+	/* should mark be in the middle of the current list? */
+	hlist_for_each_entry(lmark, head, obj_list) {
+		last = lmark;
+
+		if ((lmark->group == mark->group) && !allow_dups)
+			return -EEXIST;
+
+		cmp = fsnotify_compare_groups(lmark->group, mark->group);
+		if (cmp >= 0) {
+			hlist_add_before_rcu(&mark->obj_list, &lmark->obj_list);
+			return 0;
+		}
+	}
+
+	BUG_ON(last == NULL);
+	/* mark should be the last entry.  last is the current last entry */
+	hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);
+	return 0;
+}
+
 /*
  * Attach an initialized mark to a given group and fs object.
  * These marks may be used for the fsnotify backend to determine which
@@ -323,6 +388,24 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,
 }
 
 /*
+ * Given a list of marks, find the mark associated with given group. If found
+ * take a reference to that mark and return it, else return NULL.
+ */
+struct fsnotify_mark *fsnotify_find_mark(struct hlist_head *head,
+					 struct fsnotify_group *group)
+{
+	struct fsnotify_mark *mark;
+
+	hlist_for_each_entry(mark, head, obj_list) {
+		if (mark->group == group) {
+			fsnotify_get_mark(mark);
+			return mark;
+		}
+	}
+	return NULL;
+}
+
+/*
  * clear any marks in a group in which mark->flags & flags is true
  */
 void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group,
@@ -352,8 +435,8 @@ void fsnotify_clear_marks_by_group(struct fsnotify_group *group)
 void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old)
 {
 	assert_spin_locked(&old->lock);
-	new->i.inode = old->i.inode;
-	new->m.mnt = old->m.mnt;
+	new->inode = old->inode;
+	new->mnt = old->mnt;
 	if (old->group)
 		fsnotify_get_group(old->group);
 	new->group = old->group;