fsnotify: put inode specific fields in an fsnotify_mark in a union

The addition of marks on vfs mounts will be simplified if the inode
specific parts of a mark and the vfsmnt specific parts of a mark are
actually in a union so naming can be easy.  This patch just implements the
inode struct and the union.
Signed-off-by: Eric Paris <eparis@redhat.com>

fs/notify/dnotify/dnotify.c

@@ -70,8 +70,8 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry)
 	if (old_mask == new_mask)
 		return;
 
-	if (entry->inode)
-		fsnotify_recalc_inode_mask(entry->inode);
+	if (entry->i.inode)
+		fsnotify_recalc_inode_mask(entry->i.inode);
 }
 
 /*

fs/notify/inode_mark.c

@@ -117,7 +117,7 @@ static void fsnotify_recalc_inode_mask_locked(struct inode *inode)
 
 	assert_spin_locked(&inode->i_lock);
 
-	hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list)
+	hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i.i_list)
 		new_mask |= entry->mask;
 	inode->i_fsnotify_mask = new_mask;
 }
@@ -148,7 +148,7 @@ void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry)
 	spin_lock(&entry->lock);
 
 	group = entry->group;
-	inode = entry->inode;
+	inode = entry->i.inode;
 
 	BUG_ON(group && !inode);
 	BUG_ON(!group && inode);
@@ -165,8 +165,8 @@ void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry)
 	spin_lock(&group->mark_lock);
 	spin_lock(&inode->i_lock);
 
-	hlist_del_init(&entry->i_list);
-	entry->inode = NULL;
+	hlist_del_init(&entry->i.i_list);
+	entry->i.inode = NULL;
 
 	list_del_init(&entry->g_list);
 	entry->group = NULL;
@@ -248,14 +248,14 @@ void fsnotify_clear_marks_by_inode(struct inode *inode)
 	LIST_HEAD(free_list);
 
 	spin_lock(&inode->i_lock);
-	hlist_for_each_entry_safe(entry, pos, n, &inode->i_fsnotify_mark_entries, i_list) {
-		list_add(&entry->free_i_list, &free_list);
-		hlist_del_init(&entry->i_list);
+	hlist_for_each_entry_safe(entry, pos, n, &inode->i_fsnotify_mark_entries, i.i_list) {
+		list_add(&entry->i.free_i_list, &free_list);
+		hlist_del_init(&entry->i.i_list);
 		fsnotify_get_mark(entry);
 	}
 	spin_unlock(&inode->i_lock);
 
-	list_for_each_entry_safe(entry, lentry, &free_list, free_i_list) {
+	list_for_each_entry_safe(entry, lentry, &free_list, i.free_i_list) {
 		fsnotify_destroy_mark_by_entry(entry);
 		fsnotify_put_mark(entry);
 	}
@@ -273,7 +273,7 @@ struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *grou
 
 	assert_spin_locked(&inode->i_lock);
 
-	hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list) {
+	hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i.i_list) {
 		if (entry->group == group) {
 			fsnotify_get_mark(entry);
 			return entry;
@@ -285,7 +285,7 @@ struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *grou
 void fsnotify_duplicate_mark(struct fsnotify_mark_entry *new, struct fsnotify_mark_entry *old)
 {
 	assert_spin_locked(&old->lock);
-	new->inode = old->inode;
+	new->i.inode = old->i.inode;
 	new->group = old->group;
 	new->mask = old->mask;
 	new->free_mark = old->free_mark;
@@ -299,10 +299,10 @@ void fsnotify_init_mark(struct fsnotify_mark_entry *entry,
 {
 	spin_lock_init(&entry->lock);
 	atomic_set(&entry->refcnt, 1);
-	INIT_HLIST_NODE(&entry->i_list);
+	INIT_HLIST_NODE(&entry->i.i_list);
 	entry->group = NULL;
 	entry->mask = 0;
-	entry->inode = NULL;
+	entry->i.inode = NULL;
 	entry->free_mark = free_mark;
 }
 
@@ -350,9 +350,9 @@ int fsnotify_add_mark(struct fsnotify_mark_entry *entry,
 		lentry = fsnotify_find_mark_entry(group, inode);
 	if (!lentry) {
 		entry->group = group;
-		entry->inode = inode;
+		entry->i.inode = inode;
 
-		hlist_add_head(&entry->i_list, &inode->i_fsnotify_mark_entries);
+		hlist_add_head(&entry->i.i_list, &inode->i_fsnotify_mark_entries);
 		list_add(&entry->g_list, &group->mark_entries);
 
 		fsnotify_get_mark(entry); /* for i_list and g_list */

fs/notify/inotify/inotify_fsnotify.c

@@ -193,7 +193,7 @@ static int idr_callback(int id, void *p, void *data)
 	 */
 	if (entry)
 		printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n",
-			entry->group, entry->inode, ientry->wd);
+			entry->group, entry->i.inode, ientry->wd);
 	return 0;
 }
 

fs/notify/inotify/inotify_user.c

@@ -445,7 +445,7 @@ static void inotify_remove_from_idr(struct fsnotify_group *group,
 	if (wd == -1) {
 		WARN_ONCE(1, "%s: ientry=%p ientry->wd=%d ientry->group=%p"
 			" ientry->inode=%p\n", __func__, ientry, ientry->wd,
-			ientry->fsn_entry.group, ientry->fsn_entry.inode);
+			ientry->fsn_entry.group, ientry->fsn_entry.i.inode);
 		goto out;
 	}
 
@@ -454,7 +454,7 @@ static void inotify_remove_from_idr(struct fsnotify_group *group,
 	if (unlikely(!found_ientry)) {
 		WARN_ONCE(1, "%s: ientry=%p ientry->wd=%d ientry->group=%p"
 			" ientry->inode=%p\n", __func__, ientry, ientry->wd,
-			ientry->fsn_entry.group, ientry->fsn_entry.inode);
+			ientry->fsn_entry.group, ientry->fsn_entry.i.inode);
 		goto out;
 	}
 
@@ -468,9 +468,9 @@ static void inotify_remove_from_idr(struct fsnotify_group *group,
 			"entry->inode=%p found_ientry=%p found_ientry->wd=%d "
 			"found_ientry->group=%p found_ientry->inode=%p\n",
 			__func__, ientry, ientry->wd, ientry->fsn_entry.group,
-			ientry->fsn_entry.inode, found_ientry, found_ientry->wd,
+			ientry->fsn_entry.i.inode, found_ientry, found_ientry->wd,
 			found_ientry->fsn_entry.group,
-			found_ientry->fsn_entry.inode);
+			found_ientry->fsn_entry.i.inode);
 		goto out;
 	}
 
@@ -482,7 +482,7 @@ static void inotify_remove_from_idr(struct fsnotify_group *group,
 	if (unlikely(atomic_read(&ientry->fsn_entry.refcnt) < 3)) {
 		printk(KERN_ERR "%s: ientry=%p ientry->wd=%d ientry->group=%p"
 			" ientry->inode=%p\n", __func__, ientry, ientry->wd,
-			ientry->fsn_entry.group, ientry->fsn_entry.inode);
+			ientry->fsn_entry.group, ientry->fsn_entry.i.inode);
 		/* we can't really recover with bad ref cnting.. */
 		BUG();
 	}

include/linux/fsnotify_backend.h

@@ -226,6 +226,15 @@ struct fsnotify_event {
 	struct list_head private_data_list;	/* groups can store private data here */
 };
 
+/*
+ * Inode specific fields in an fsnotify_mark_entry
+ */
+struct fsnotify_inode_mark {
+	struct inode *inode;		/* inode this entry is associated with */
+	struct hlist_node i_list;	/* list of mark_entries by inode->i_fsnotify_mark_entries */
+	struct list_head free_i_list;	/* tmp list used when freeing this mark */
+};
+
 /*
  * a mark is simply an entry attached to an in core inode which allows an
  * fsnotify listener to indicate they are either no longer interested in events
@@ -241,12 +250,12 @@ struct fsnotify_mark_entry {
 	/* we hold ref for each i_list and g_list.  also one ref for each 'thing'
 	 * in kernel that found and may be using this mark. */
 	atomic_t refcnt;		/* active things looking at this mark */
-	struct inode *inode;		/* inode this entry is associated with */
 	struct fsnotify_group *group;	/* group this mark entry is for */
-	struct hlist_node i_list;	/* list of mark_entries by inode->i_fsnotify_mark_entries */
 	struct list_head g_list;	/* list of mark_entries by group->i_fsnotify_mark_entries */
-	spinlock_t lock;		/* protect group, inode, and killme */
-	struct list_head free_i_list;	/* tmp list used when freeing this mark */
+	spinlock_t lock;		/* protect group and inode */
+	union {
+		struct fsnotify_inode_mark i;
+	};
 	struct list_head free_g_list;	/* tmp list used when freeing this mark */
 	void (*free_mark)(struct fsnotify_mark_entry *entry); /* called on final put+free */
 };

kernel/audit_tree.c

@@ -179,9 +179,9 @@ static void insert_hash(struct audit_chunk *chunk)
 	struct fsnotify_mark_entry *entry = &chunk->mark;
 	struct list_head *list;
 
-	if (!entry->inode)
+	if (!entry->i.inode)
 		return;
-	list = chunk_hash(entry->inode);
+	list = chunk_hash(entry->i.inode);
 	list_add_rcu(&chunk->hash, list);
 }
 
@@ -193,7 +193,7 @@ struct audit_chunk *audit_tree_lookup(const struct inode *inode)
 
 	list_for_each_entry_rcu(p, list, hash) {
 		/* mark.inode may have gone NULL, but who cares? */
-		if (p->mark.inode == inode) {
+		if (p->mark.i.inode == inode) {
 			atomic_long_inc(&p->refs);
 			return p;
 		}
@@ -233,7 +233,7 @@ static void untag_chunk(struct node *p)
 	spin_unlock(&hash_lock);
 
 	spin_lock(&entry->lock);
-	if (chunk->dead || !entry->inode) {
+	if (chunk->dead || !entry->i.inode) {
 		spin_unlock(&entry->lock);
 		goto out;
 	}
@@ -259,7 +259,7 @@ static void untag_chunk(struct node *p)
 	if (!new)
 		goto Fallback;
 	fsnotify_duplicate_mark(&new->mark, entry);
-	if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, 1)) {
+	if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, 1)) {
 		free_chunk(new);
 		goto Fallback;
 	}
@@ -388,7 +388,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
 	chunk_entry = &chunk->mark;
 
 	spin_lock(&old_entry->lock);
-	if (!old_entry->inode) {
+	if (!old_entry->i.inode) {
 		/* old_entry is being shot, lets just lie */
 		spin_unlock(&old_entry->lock);
 		fsnotify_put_mark(old_entry);
@@ -397,7 +397,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
 	}
 
 	fsnotify_duplicate_mark(chunk_entry, old_entry);
-	if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, 1)) {
+	if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, 1)) {
 		spin_unlock(&old_entry->lock);
 		free_chunk(chunk);
 		fsnotify_put_mark(old_entry);
@@ -605,7 +605,7 @@ void audit_trim_trees(void)
 		list_for_each_entry(node, &tree->chunks, list) {
 			struct audit_chunk *chunk = find_chunk(node);
 			/* this could be NULL if the watch is dieing else where... */
-			struct inode *inode = chunk->mark.inode;
+			struct inode *inode = chunk->mark.i.inode;
 			node->index |= 1U<<31;
 			if (iterate_mounts(compare_root, inode, root_mnt))
 				node->index &= ~(1U<<31);