@@ -198,6 +198,14 @@ void eventfs_set_ef_status_free(struct dentry *dentry)
if (!ef)
goto out;
+ /*
+ * If ef was freed, then the LSB bit is set for d_fsdata.
+ * But this should not happen, as it should still have a
+ * ref count that prevents it. Warn in case it does.
+ */
+ if (WARN_ON_ONCE((unsigned long)ef & 1))
+ goto out;
+
dentry->d_fsdata = NULL;
ef->dentry = NULL;
out:
@@ -656,3 +664,138 @@ int eventfs_add_file(const char *name, umode_t mode,
mutex_unlock(&eventfs_mutex);
return 0;
}
+
+static void free_ef(struct rcu_head *head)
+{
+ struct eventfs_file *ef = container_of(head, struct eventfs_file, rcu);
+
+ kfree(ef->name);
+ kfree(ef->ei);
+ kfree(ef);
+}
+
+/**
+ * eventfs_remove_rec - remove eventfs dir or file from list
+ * @ef: eventfs_file to be removed.
+ * @head: to create list of eventfs_file to be deleted
+ * @level: to check recursion depth
+ *
+ * The helper function eventfs_remove_rec() is used to clean up and free the
+ * associated data from eventfs for both of the added functions.
+ */
+static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, int level)
+{
+ struct eventfs_file *ef_child;
+
+ if (!ef)
+ return;
+ /*
+ * Check recursion depth. It should never be greater than 3:
+ * 0 - events/
+ * 1 - events/group/
+ * 2 - events/group/event/
+ * 3 - events/group/event/file
+ */
+ if (WARN_ON_ONCE(level > 3))
+ return;
+
+ if (ef->ei) {
+ /* search for nested folders or files */
+ list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list,
+ lockdep_is_held(&eventfs_mutex)) {
+ eventfs_remove_rec(ef_child, head, level + 1);
+ }
+ }
+
+ list_del_rcu(&ef->list);
+ list_add_tail(&ef->del_list, head);
+}
+
+/**
+ * eventfs_remove - remove eventfs dir or file from list
+ * @ef: eventfs_file to be removed.
+ *
+ * This function acquire the eventfs_mutex lock and call eventfs_remove_rec()
+ */
+void eventfs_remove(struct eventfs_file *ef)
+{
+ struct eventfs_file *tmp;
+ LIST_HEAD(ef_del_list);
+ struct dentry *dentry_list = NULL;
+ struct dentry *dentry;
+
+ if (!ef)
+ return;
+
+ mutex_lock(&eventfs_mutex);
+ eventfs_remove_rec(ef, &ef_del_list, 0);
+ list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) {
+ if (ef->dentry) {
+ unsigned long ptr = (unsigned long)dentry_list;
+
+ /* Keep the dentry from being freed yet */
+ dget(ef->dentry);
+
+ /*
+ * Paranoid: The dget() above should prevent the dentry
+ * from being freed and calling eventfs_set_ef_status_free().
+ * But just in case, set the link list LSB pointer to 1
+ * and have eventfs_set_ef_status_free() check that to
+ * make sure that if it does happen, it will not think
+ * the d_fsdata is an event_file.
+ *
+ * For this to work, no event_file should be allocated
+ * on a odd space, as the ef should always be allocated
+ * to be at least word aligned. Check for that too.
+ */
+ WARN_ON_ONCE(ptr & 1);
+
+ ef->dentry->d_fsdata = (void *)(ptr | 1);
+ dentry_list = ef->dentry;
+ ef->dentry = NULL;
+ }
+ call_srcu(&eventfs_srcu, &ef->rcu, free_ef);
+ }
+ mutex_unlock(&eventfs_mutex);
+
+ while (dentry_list) {
+ unsigned long ptr;
+
+ dentry = dentry_list;
+ ptr = (unsigned long)dentry->d_fsdata & ~1UL;
+ dentry_list = (struct dentry *)ptr;
+ dentry->d_fsdata = NULL;
+ d_invalidate(dentry);
+ mutex_lock(&eventfs_mutex);
+ /* dentry should now have at least a single reference */
+ WARN_ONCE((int)d_count(dentry) < 1,
+ "dentry %p less than one reference (%d) after invalidate\n",
+ dentry, d_count(dentry));
+ mutex_unlock(&eventfs_mutex);
+ dput(dentry);
+ }
+}
+
+/**
+ * eventfs_remove_events_dir - remove eventfs dir or file from list
+ * @dentry: events's dentry to be removed.
+ *
+ * This function remove events main directory
+ */
+void eventfs_remove_events_dir(struct dentry *dentry)
+{
+ struct tracefs_inode *ti;
+ struct eventfs_inode *ei;
+
+ if (!dentry || !dentry->d_inode)
+ return;
+
+ ti = get_tracefs(dentry->d_inode);
+ if (!ti || !(ti->flags & TRACEFS_EVENT_INODE))
+ return;
+
+ ei = ti->private;
+ d_invalidate(dentry);
+ dput(dentry);
+ kfree(ei);
+}
@@ -40,6 +40,10 @@ int eventfs_add_events_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops);
+void eventfs_remove(struct eventfs_file *ef);
+
+void eventfs_remove_events_dir(struct dentry *dentry);
+
struct dentry *tracefs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops);