Merge tag 'fsnotify_for_v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:
 "fsnotify cleanups from Amir and a small inotify improvement"

* tag 'fsnotify_for_v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  inotify: Add flag IN_MASK_CREATE for inotify_add_watch()
  fanotify: factor out helpers to add/remove mark
  fsnotify: add helper to get mask from connector
  fsnotify: let connector point to an abstract object
  fsnotify: pass connp and object type to fsnotify_add_mark()
  fsnotify: use typedef fsnotify_connp_t for brevity

fs/notify/fanotify/fanotify_user.c

@@ -524,17 +524,16 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
 	return mask & oldmask;
 }
 
-static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
-					 struct vfsmount *mnt, __u32 mask,
-					 unsigned int flags)
+static int fanotify_remove_mark(struct fsnotify_group *group,
+				fsnotify_connp_t *connp, __u32 mask,
+				unsigned int flags)
 {
 	struct fsnotify_mark *fsn_mark = NULL;
 	__u32 removed;
 	int destroy_mark;
 
 	mutex_lock(&group->mark_mutex);
-	fsn_mark = fsnotify_find_mark(&real_mount(mnt)->mnt_fsnotify_marks,
-				      group);
+	fsn_mark = fsnotify_find_mark(connp, group);
 	if (!fsn_mark) {
 		mutex_unlock(&group->mark_mutex);
 		return -ENOENT;
@@ -542,47 +541,33 @@ static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
 
 	removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
 						 &destroy_mark);
-	if (removed & real_mount(mnt)->mnt_fsnotify_mask)
-		fsnotify_recalc_mask(real_mount(mnt)->mnt_fsnotify_marks);
+	if (removed & fsnotify_conn_mask(fsn_mark->connector))
+		fsnotify_recalc_mask(fsn_mark->connector);
 	if (destroy_mark)
 		fsnotify_detach_mark(fsn_mark);
 	mutex_unlock(&group->mark_mutex);
 	if (destroy_mark)
 		fsnotify_free_mark(fsn_mark);
 
+	/* matches the fsnotify_find_mark() */
 	fsnotify_put_mark(fsn_mark);
 	return 0;
 }
 
+static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
+					 struct vfsmount *mnt, __u32 mask,
+					 unsigned int flags)
+{
+	return fanotify_remove_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
+				    mask, flags);
+}
+
 static int fanotify_remove_inode_mark(struct fsnotify_group *group,
 				      struct inode *inode, __u32 mask,
 				      unsigned int flags)
 {
-	struct fsnotify_mark *fsn_mark = NULL;
-	__u32 removed;
-	int destroy_mark;
-
-	mutex_lock(&group->mark_mutex);
-	fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
-	if (!fsn_mark) {
-		mutex_unlock(&group->mark_mutex);
-		return -ENOENT;
-	}
-
-	removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags,
-						 &destroy_mark);
-	if (removed & inode->i_fsnotify_mask)
-		fsnotify_recalc_mask(inode->i_fsnotify_marks);
-	if (destroy_mark)
-		fsnotify_detach_mark(fsn_mark);
-	mutex_unlock(&group->mark_mutex);
-	if (destroy_mark)
-		fsnotify_free_mark(fsn_mark);
-
-	/* matches the fsnotify_find_mark() */
-	fsnotify_put_mark(fsn_mark);
-
-	return 0;
+	return fanotify_remove_mark(group, &inode->i_fsnotify_marks, mask,
+				    flags);
 }
 
 static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
@@ -615,8 +600,8 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
 }
 
 static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
-						   struct inode *inode,
-						   struct vfsmount *mnt)
+						   fsnotify_connp_t *connp,
+						   unsigned int type)
 {
 	struct fsnotify_mark *mark;
 	int ret;
@@ -629,7 +614,7 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
 		return ERR_PTR(-ENOMEM);
 
 	fsnotify_init_mark(mark, group);
-	ret = fsnotify_add_mark_locked(mark, inode, mnt, 0);
+	ret = fsnotify_add_mark_locked(mark, connp, type, 0);
 	if (ret) {
 		fsnotify_put_mark(mark);
 		return ERR_PTR(ret);
@@ -639,39 +624,43 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
 }
 
 
-static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
-				      struct vfsmount *mnt, __u32 mask,
-				      unsigned int flags)
+static int fanotify_add_mark(struct fsnotify_group *group,
+			     fsnotify_connp_t *connp, unsigned int type,
+			     __u32 mask, unsigned int flags)
 {
 	struct fsnotify_mark *fsn_mark;
 	__u32 added;
 
 	mutex_lock(&group->mark_mutex);
-	fsn_mark = fsnotify_find_mark(&real_mount(mnt)->mnt_fsnotify_marks,
-				      group);
+	fsn_mark = fsnotify_find_mark(connp, group);
 	if (!fsn_mark) {
-		fsn_mark = fanotify_add_new_mark(group, NULL, mnt);
+		fsn_mark = fanotify_add_new_mark(group, connp, type);
 		if (IS_ERR(fsn_mark)) {
 			mutex_unlock(&group->mark_mutex);
 			return PTR_ERR(fsn_mark);
 		}
 	}
 	added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
-	if (added & ~real_mount(mnt)->mnt_fsnotify_mask)
-		fsnotify_recalc_mask(real_mount(mnt)->mnt_fsnotify_marks);
+	if (added & ~fsnotify_conn_mask(fsn_mark->connector))
+		fsnotify_recalc_mask(fsn_mark->connector);
 	mutex_unlock(&group->mark_mutex);
 
 	fsnotify_put_mark(fsn_mark);
 	return 0;
 }
 
+static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
+				      struct vfsmount *mnt, __u32 mask,
+				      unsigned int flags)
+{
+	return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
+				 FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags);
+}
+
 static int fanotify_add_inode_mark(struct fsnotify_group *group,
 				   struct inode *inode, __u32 mask,
 				   unsigned int flags)
 {
-	struct fsnotify_mark *fsn_mark;
-	__u32 added;
-
 	pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
 
 	/*
@@ -684,22 +673,8 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
 	    (atomic_read(&inode->i_writecount) > 0))
 		return 0;
 
-	mutex_lock(&group->mark_mutex);
-	fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
-	if (!fsn_mark) {
-		fsn_mark = fanotify_add_new_mark(group, inode, NULL);
-		if (IS_ERR(fsn_mark)) {
-			mutex_unlock(&group->mark_mutex);
-			return PTR_ERR(fsn_mark);
-		}
-	}
-	added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
-	if (added & ~inode->i_fsnotify_mask)
-		fsnotify_recalc_mask(inode->i_fsnotify_marks);
-	mutex_unlock(&group->mark_mutex);
-
-	fsnotify_put_mark(fsn_mark);
-	return 0;
+	return fanotify_add_mark(group, &inode->i_fsnotify_marks,
+				 FSNOTIFY_OBJ_TYPE_INODE, mask, flags);
 }
 
 /* fanotify syscalls */

fs/notify/fdinfo.c

@@ -15,7 +15,7 @@
 #include <linux/exportfs.h>
 
 #include "inotify/inotify.h"
-#include "../fs/mount.h"
+#include "fsnotify.h"
 
 #if defined(CONFIG_PROC_FS)
 
@@ -81,7 +81,7 @@ static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 		return;
 
 	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
-	inode = igrab(mark->connector->inode);
+	inode = igrab(fsnotify_conn_inode(mark->connector));
 	if (inode) {
 		/*
 		 * IN_ALL_EVENTS represents all of the mask bits
@@ -117,7 +117,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 		mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
 
 	if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
-		inode = igrab(mark->connector->inode);
+		inode = igrab(fsnotify_conn_inode(mark->connector));
 		if (!inode)
 			return;
 		seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
@@ -127,7 +127,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 		seq_putc(m, '\n');
 		iput(inode);
 	} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
-		struct mount *mnt = real_mount(mark->connector->mnt);
+		struct mount *mnt = fsnotify_conn_mount(mark->connector);
 
 		seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
 			   mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);

fs/notify/fsnotify.h

@@ -9,6 +9,18 @@
 
 #include "../mount.h"
 
+static inline struct inode *fsnotify_conn_inode(
+				struct fsnotify_mark_connector *conn)
+{
+	return container_of(conn->obj, struct inode, i_fsnotify_marks);
+}
+
+static inline struct mount *fsnotify_conn_mount(
+				struct fsnotify_mark_connector *conn)
+{
+	return container_of(conn->obj, struct mount, mnt_fsnotify_marks);
+}
+
 /* destroy all events sitting in this groups notification queue */
 extern void fsnotify_flush_notify(struct fsnotify_group *group);
 
@@ -19,8 +31,8 @@ extern struct srcu_struct fsnotify_mark_srcu;
 extern int fsnotify_compare_groups(struct fsnotify_group *a,
 				   struct fsnotify_group *b);
 
-/* Destroy all marks connected via given connector */
-extern void fsnotify_destroy_marks(struct fsnotify_mark_connector __rcu **connp);
+/* Destroy all marks attached to an object via connector */
+extern void fsnotify_destroy_marks(fsnotify_connp_t *connp);
 /* run the list of all marks associated with inode and destroy them */
 static inline void fsnotify_clear_marks_by_inode(struct inode *inode)
 {

fs/notify/inotify/inotify_user.c

@@ -510,6 +510,7 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 	__u32 old_mask, new_mask;
 	__u32 mask;
 	int add = (arg & IN_MASK_ADD);
+	int create = (arg & IN_MASK_CREATE);
 	int ret;
 
 	mask = inotify_arg_to_mask(arg);
@@ -517,6 +518,8 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 	fsn_mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
 	if (!fsn_mark)
 		return -ENOENT;
+	else if (create)
+		return -EEXIST;
 
 	i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
 
@@ -718,6 +721,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
 	if (unlikely(!f.file))
 		return -EBADF;
 
+	/* IN_MASK_ADD and IN_MASK_CREATE don't make sense together */
+	if (unlikely((mask & IN_MASK_ADD) && (mask & IN_MASK_CREATE)))
+		return -EINVAL;
+
 	/* verify that this is indeed an inotify instance */
 	if (unlikely(f.file->f_op != &inotify_fops)) {
 		ret = -EINVAL;
@@ -806,7 +813,7 @@ static int __init inotify_user_setup(void)
 	BUILD_BUG_ON(IN_ISDIR != FS_ISDIR);
 	BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
 
-	BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
+	BUG_ON(hweight32(ALL_INOTIFY_BITS) != 22);
 
 	inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
 

fs/notify/mark.c

@@ -109,6 +109,23 @@ void fsnotify_get_mark(struct fsnotify_mark *mark)
 	refcount_inc(&mark->refcnt);
 }
 
+static __u32 *fsnotify_conn_mask_p(struct fsnotify_mark_connector *conn)
+{
+	if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
+		return &fsnotify_conn_inode(conn)->i_fsnotify_mask;
+	else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
+		return &fsnotify_conn_mount(conn)->mnt_fsnotify_mask;
+	return NULL;
+}
+
+__u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn)
+{
+	if (WARN_ON(!fsnotify_valid_obj_type(conn->type)))
+		return 0;
+
+	return *fsnotify_conn_mask_p(conn);
+}
+
 static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
 {
 	u32 new_mask = 0;
@@ -119,15 +136,15 @@ static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
 		if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)
 			new_mask |= mark->mask;
 	}
-	if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
-		conn->inode->i_fsnotify_mask = new_mask;
-	else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
-		real_mount(conn->mnt)->mnt_fsnotify_mask = new_mask;
+	if (WARN_ON(!fsnotify_valid_obj_type(conn->type)))
+		return;
+
+	*fsnotify_conn_mask_p(conn) = new_mask;
 }
 
 /*
  * Calculate mask of events for a list of marks. The caller must make sure
- * connector and connector->inode cannot disappear under us.  Callers achieve
+ * connector and connector->obj cannot disappear under us.  Callers achieve
  * this by holding a mark->lock or mark->group->mark_mutex for a mark on this
  * list.
  */
@@ -140,7 +157,8 @@ void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
 	__fsnotify_recalc_mask(conn);
 	spin_unlock(&conn->lock);
 	if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
-		__fsnotify_update_child_dentry_flags(conn->inode);
+		__fsnotify_update_child_dentry_flags(
+					fsnotify_conn_inode(conn));
 }
 
 /* Free all connectors queued for freeing once SRCU period ends */
@@ -166,20 +184,20 @@ static struct inode *fsnotify_detach_connector_from_object(
 {
 	struct inode *inode = NULL;
 
+	if (conn->type == FSNOTIFY_OBJ_TYPE_DETACHED)
+		return NULL;
+
 	if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
-		inode = conn->inode;
-		rcu_assign_pointer(inode->i_fsnotify_marks, NULL);
+		inode = fsnotify_conn_inode(conn);
 		inode->i_fsnotify_mask = 0;
-		conn->inode = NULL;
-		conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
 	} else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
-		rcu_assign_pointer(real_mount(conn->mnt)->mnt_fsnotify_marks,
-				   NULL);
-		real_mount(conn->mnt)->mnt_fsnotify_mask = 0;
-		conn->mnt = NULL;
-		conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
+		fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
 	}
 
+	rcu_assign_pointer(*(conn->obj), NULL);
+	conn->obj = NULL;
+	conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
+
 	return inode;
 }
 
@@ -436,11 +454,10 @@ int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b)
 	return -1;
 }
 
-static int fsnotify_attach_connector_to_object(
-				struct fsnotify_mark_connector __rcu **connp,
-				struct inode *inode,
-				struct vfsmount *mnt)
+static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
+					       unsigned int type)
 {
+	struct inode *inode = NULL;
 	struct fsnotify_mark_connector *conn;
 
 	conn = kmem_cache_alloc(fsnotify_mark_connector_cachep, GFP_KERNEL);
@@ -448,13 +465,10 @@ static int fsnotify_attach_connector_to_object(
 		return -ENOMEM;
 	spin_lock_init(&conn->lock);
 	INIT_HLIST_HEAD(&conn->list);
-	if (inode) {
-		conn->type = FSNOTIFY_OBJ_TYPE_INODE;
-		conn->inode = igrab(inode);
-	} else {
-		conn->type = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
-		conn->mnt = mnt;
-	}
+	conn->type = type;
+	conn->obj = connp;
+	if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
+		inode = igrab(fsnotify_conn_inode(conn));
 	/*
 	 * cmpxchg() provides the barrier so that readers of *connp can see
 	 * only initialized structure
@@ -476,7 +490,7 @@ static int fsnotify_attach_connector_to_object(
  * they are sure list cannot go away under them.
  */
 static struct fsnotify_mark_connector *fsnotify_grab_connector(
-				struct fsnotify_mark_connector __rcu **connp)
+						fsnotify_connp_t *connp)
 {
 	struct fsnotify_mark_connector *conn;
 	int idx;
@@ -503,27 +517,22 @@ out:
  * priority, highest number first, and then by the group's location in memory.
  */
 static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
-				  struct inode *inode, struct vfsmount *mnt,
+				  fsnotify_connp_t *connp, unsigned int type,
 				  int allow_dups)
 {
 	struct fsnotify_mark *lmark, *last = NULL;
 	struct fsnotify_mark_connector *conn;
-	struct fsnotify_mark_connector __rcu **connp;
 	int cmp;
 	int err = 0;
 
-	if (WARN_ON(!inode && !mnt))
+	if (WARN_ON(!fsnotify_valid_obj_type(type)))
 		return -EINVAL;
-	if (inode)
-		connp = &inode->i_fsnotify_marks;
-	else
-		connp = &real_mount(mnt)->mnt_fsnotify_marks;
 restart:
 	spin_lock(&mark->lock);
 	conn = fsnotify_grab_connector(connp);
 	if (!conn) {
 		spin_unlock(&mark->lock);
-		err = fsnotify_attach_connector_to_object(connp, inode, mnt);
+		err = fsnotify_attach_connector_to_object(connp, type);
 		if (err)
 			return err;
 		goto restart;
@@ -569,14 +578,13 @@ out_err:
  * These marks may be used for the fsnotify backend to determine which
  * event types should be delivered to which group.
  */
-int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct inode *inode,
-			     struct vfsmount *mnt, int allow_dups)
+int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
+			     fsnotify_connp_t *connp, unsigned int type,
+			     int allow_dups)
 {
 	struct fsnotify_group *group = mark->group;
 	int ret = 0;
 
-	BUG_ON(inode && mnt);
-	BUG_ON(!inode && !mnt);
 	BUG_ON(!mutex_is_locked(&group->mark_mutex));
 
 	/*
@@ -593,7 +601,7 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct inode *inode,
 	fsnotify_get_mark(mark); /* for g_list */
 	spin_unlock(&mark->lock);
 
-	ret = fsnotify_add_mark_list(mark, inode, mnt, allow_dups);
+	ret = fsnotify_add_mark_list(mark, connp, type, allow_dups);
 	if (ret)
 		goto err;
 
@@ -613,14 +621,14 @@ err:
 	return ret;
 }
 
-int fsnotify_add_mark(struct fsnotify_mark *mark, struct inode *inode,
-		      struct vfsmount *mnt, int allow_dups)
+int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_connp_t *connp,
+		      unsigned int type, int allow_dups)
 {
 	int ret;
 	struct fsnotify_group *group = mark->group;
 
 	mutex_lock(&group->mark_mutex);
-	ret = fsnotify_add_mark_locked(mark, inode, mnt, allow_dups);
+	ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups);
 	mutex_unlock(&group->mark_mutex);
 	return ret;
 }
@@ -629,9 +637,8 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, struct inode *inode,
  * 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 fsnotify_mark_connector __rcu **connp,
-				struct fsnotify_group *group)
+struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
+					 struct fsnotify_group *group)
 {
 	struct fsnotify_mark_connector *conn;
 	struct fsnotify_mark *mark;
@@ -697,8 +704,8 @@ clear:
 	}
 }
 
-/* Destroy all marks attached to inode / vfsmount */
-void fsnotify_destroy_marks(struct fsnotify_mark_connector __rcu **connp)
+/* Destroy all marks attached to an object via connector */
+void fsnotify_destroy_marks(fsnotify_connp_t *connp)
 {
 	struct fsnotify_mark_connector *conn;
 	struct fsnotify_mark *mark, *old_mark = NULL;

include/linux/fsnotify_backend.h

@@ -210,6 +210,11 @@ enum fsnotify_obj_type {
 #define FSNOTIFY_OBJ_TYPE_VFSMOUNT_FL	(1U << FSNOTIFY_OBJ_TYPE_VFSMOUNT)
 #define FSNOTIFY_OBJ_ALL_TYPES_MASK	((1U << FSNOTIFY_OBJ_TYPE_COUNT) - 1)
 
+static inline bool fsnotify_valid_obj_type(unsigned int type)
+{
+	return (type < FSNOTIFY_OBJ_TYPE_COUNT);
+}
+
 struct fsnotify_iter_info {
 	struct fsnotify_mark *marks[FSNOTIFY_OBJ_TYPE_COUNT];
 	unsigned int report_mask;
@@ -250,6 +255,13 @@ FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
 #define fsnotify_foreach_obj_type(type) \
 	for (type = 0; type < FSNOTIFY_OBJ_TYPE_COUNT; type++)
 
+/*
+ * fsnotify_connp_t is what we embed in objects which connector can be attached
+ * to. fsnotify_connp_t * is how we refer from connector back to object.
+ */
+struct fsnotify_mark_connector;
+typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
+
 /*
  * Inode / vfsmount point to this structure which tracks all marks attached to
  * the inode / vfsmount. The reference to inode / vfsmount is held by this
@@ -259,9 +271,9 @@ FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
 struct fsnotify_mark_connector {
 	spinlock_t lock;
 	unsigned int type;	/* Type of object [lock] */
-	union {	/* Object pointer [lock] */
-		struct inode *inode;
-		struct vfsmount *mnt;
+	union {
+		/* Object pointer [lock] */
+		fsnotify_connp_t *obj;
 		/* Used listing heads to free after srcu period expires */
 		struct fsnotify_mark_connector *destroy_next;
 	};
@@ -389,32 +401,36 @@ extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group
 
 /* functions used to manipulate the marks attached to inodes */
 
+/* Get mask of events for a list of marks */
+extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn);
 /* Calculate mask of events for a list of marks */
 extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
 extern void fsnotify_init_mark(struct fsnotify_mark *mark,
 			       struct fsnotify_group *group);
 /* Find mark belonging to given group in the list of marks */
-extern struct fsnotify_mark *fsnotify_find_mark(
-				struct fsnotify_mark_connector __rcu **connp,
-				struct fsnotify_group *group);
-/* attach the mark to the inode or vfsmount */
-extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct inode *inode,
-			     struct vfsmount *mnt, int allow_dups);
+extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
+						struct fsnotify_group *group);
+/* attach the mark to the object */
+extern int fsnotify_add_mark(struct fsnotify_mark *mark,
+			     fsnotify_connp_t *connp, unsigned int type,
+			     int allow_dups);
 extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
-				    struct inode *inode, struct vfsmount *mnt,
+				    fsnotify_connp_t *connp, unsigned int type,
 				    int allow_dups);
 /* attach the mark to the inode */
 static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
 					  struct inode *inode,
 					  int allow_dups)
 {
-	return fsnotify_add_mark(mark, inode, NULL, allow_dups);
+	return fsnotify_add_mark(mark, &inode->i_fsnotify_marks,
+				 FSNOTIFY_OBJ_TYPE_INODE, allow_dups);
 }
 static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark,
 						 struct inode *inode,
 						 int allow_dups)
 {
-	return fsnotify_add_mark_locked(mark, inode, NULL, allow_dups);
+	return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks,
+					FSNOTIFY_OBJ_TYPE_INODE, allow_dups);
 }
 /* given a group and a mark, flag mark to be freed when all references are dropped */
 extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,

include/linux/inotify.h

@@ -18,6 +18,6 @@ extern struct ctl_table inotify_table[]; /* for sysctl */
 			  IN_DELETE_SELF | IN_MOVE_SELF | IN_UNMOUNT | \
 			  IN_Q_OVERFLOW | IN_IGNORED | IN_ONLYDIR | \
 			  IN_DONT_FOLLOW | IN_EXCL_UNLINK | IN_MASK_ADD | \
-			  IN_ISDIR | IN_ONESHOT)
+			  IN_MASK_CREATE | IN_ISDIR | IN_ONESHOT)
 
 #endif	/* _LINUX_INOTIFY_H */

include/uapi/linux/inotify.h

@@ -53,6 +53,7 @@ struct inotify_event {
 #define IN_ONLYDIR		0x01000000	/* only watch the path if it is a directory */
 #define IN_DONT_FOLLOW		0x02000000	/* don't follow a sym link */
 #define IN_EXCL_UNLINK		0x04000000	/* exclude events on unlinked objects */
+#define IN_MASK_CREATE		0x10000000	/* only create watches */
 #define IN_MASK_ADD		0x20000000	/* add to the mask of an already existing watch */
 #define IN_ISDIR		0x40000000	/* event occurred against dir */
 #define IN_ONESHOT		0x80000000	/* only send event once */

kernel/audit_tree.c

@@ -168,7 +168,8 @@ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(hash_lock);
 /* Function to return search key in our hash from inode. */
 static unsigned long inode_to_key(const struct inode *inode)
 {
-	return (unsigned long)inode;
+	/* Use address pointed to by connector->obj as the key */
+	return (unsigned long)&inode->i_fsnotify_marks;
 }
 
 /*
@@ -183,7 +184,7 @@ static unsigned long chunk_to_key(struct audit_chunk *chunk)
 	 */
 	if (WARN_ON_ONCE(!chunk->mark.connector))
 		return 0;
-	return (unsigned long)chunk->mark.connector->inode;
+	return (unsigned long)chunk->mark.connector->obj;
 }
 
 static inline struct list_head *chunk_hash(unsigned long key)
@@ -258,7 +259,7 @@ static void untag_chunk(struct node *p)
 	spin_lock(&entry->lock);
 	/*
 	 * mark_mutex protects mark from getting detached and thus also from
-	 * mark->connector->inode getting NULL.
+	 * mark->connector->obj getting NULL.
 	 */
 	if (chunk->dead || !(entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
 		spin_unlock(&entry->lock);
@@ -288,8 +289,8 @@ static void untag_chunk(struct node *p)
 	if (!new)
 		goto Fallback;
 
-	if (fsnotify_add_inode_mark_locked(&new->mark, entry->connector->inode,
-					   1)) {
+	if (fsnotify_add_mark_locked(&new->mark, entry->connector->obj,
+				     FSNOTIFY_OBJ_TYPE_INODE, 1)) {
 		fsnotify_put_mark(&new->mark);
 		goto Fallback;
 	}
@@ -423,7 +424,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
 	spin_lock(&old_entry->lock);
 	/*
 	 * mark_mutex protects mark from getting detached and thus also from
-	 * mark->connector->inode getting NULL.
+	 * mark->connector->obj getting NULL.
 	 */
 	if (!(old_entry->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
 		/* old_entry is being shot, lets just lie */
@@ -434,8 +435,8 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
 		return -ENOENT;
 	}
 
-	if (fsnotify_add_inode_mark_locked(chunk_entry,
-			     old_entry->connector->inode, 1)) {
+	if (fsnotify_add_mark_locked(chunk_entry, old_entry->connector->obj,
+				     FSNOTIFY_OBJ_TYPE_INODE, 1)) {
 		spin_unlock(&old_entry->lock);
 		mutex_unlock(&old_entry->group->mark_mutex);
 		fsnotify_put_mark(chunk_entry);