fsnotify: use type id to identify connector object type

An fsnotify_mark_connector is referencing a single type of object
(either inode or vfsmount). Instead of storing a type mask in
connector->flags, store a single type id in connector->type to
identify the type of object.

When a connector object is detached from the object, its type is set
to FSNOTIFY_OBJ_TYPE_DETACHED and this object is not going to be
reused.

The function fsnotify_clear_marks_by_group() is the only place where
type mask was used, so use type flags instead of type id to this
function.

This change is going to be more convenient when adding a new object
type (super block).

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

3 files changed, 18 insertions, 19 deletions

diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index d478629c728b..10aac1942c9f 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -77,7 +77,7 @@ static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
         struct inotify_inode_mark *inode_mark;
         struct inode *inode;
 
-        if (!(mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE))
+        if (mark->connector->type != FSNOTIFY_OBJ_TYPE_INODE)
                 return;
 
         inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
@@ -116,7 +116,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
         if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
                 mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
 
-        if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_INODE) {
+        if (mark->connector->type == FSNOTIFY_OBJ_TYPE_INODE) {
                 inode = igrab(mark->connector->inode);
                 if (!inode)
                         return;
@@ -126,7 +126,7 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
                 show_mark_fhandle(m, inode);
                 seq_putc(m, '\n');
                 iput(inode);
-        } else if (mark->connector->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
+        } else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
                 struct mount *mnt = real_mount(mark->connector->mnt);
 
                 seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
diff --git a/fs/notify/group.c b/fs/notify/group.c
index b7a4b6a69efa..aa5468f23e45 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -67,7 +67,7 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
         fsnotify_group_stop_queueing(group);
 
         /* Clear all marks for this group and queue them for destruction */
-        fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_ALL_TYPES);
+        fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_ALL_TYPES_MASK);
 
         /*
          * Some marks can still be pinned when waiting for response from
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index e9191b416434..ef44808b28ca 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -119,9 +119,9 @@ static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
                 if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)
                         new_mask |= mark->mask;
         }
-        if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE)
+        if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
                 conn->inode->i_fsnotify_mask = new_mask;
-        else if (conn->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT)
+        else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
                 real_mount(conn->mnt)->mnt_fsnotify_mask = new_mask;
 }
 
@@ -139,7 +139,7 @@ void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
         spin_lock(&conn->lock);
         __fsnotify_recalc_mask(conn);
         spin_unlock(&conn->lock);
-        if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE)
+        if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
                 __fsnotify_update_child_dentry_flags(conn->inode);
 }
 
@@ -166,18 +166,18 @@ static struct inode *fsnotify_detach_connector_from_object(
 {
         struct inode *inode = NULL;
 
-        if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE) {
+        if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) {
                 inode = conn->inode;
                 rcu_assign_pointer(inode->i_fsnotify_marks, NULL);
                 inode->i_fsnotify_mask = 0;
                 conn->inode = NULL;
-                conn->flags &= ~FSNOTIFY_OBJ_TYPE_INODE;
-        } else if (conn->flags & FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
+                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->flags &= ~FSNOTIFY_OBJ_TYPE_VFSMOUNT;
+                conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
         }
 
         return inode;
@@ -442,10 +442,10 @@ static int fsnotify_attach_connector_to_object(
         spin_lock_init(&conn->lock);
         INIT_HLIST_HEAD(&conn->list);
         if (inode) {
-                conn->flags = FSNOTIFY_OBJ_TYPE_INODE;
+                conn->type = FSNOTIFY_OBJ_TYPE_INODE;
                 conn->inode = igrab(inode);
         } else {
-                conn->flags = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
+                conn->type = FSNOTIFY_OBJ_TYPE_VFSMOUNT;
                 conn->mnt = mnt;
         }
         /*
@@ -479,8 +479,7 @@ static struct fsnotify_mark_connector *fsnotify_grab_connector(
         if (!conn)
                 goto out;
         spin_lock(&conn->lock);
-        if (!(conn->flags & (FSNOTIFY_OBJ_TYPE_INODE |
-                             FSNOTIFY_OBJ_TYPE_VFSMOUNT))) {
+        if (conn->type == FSNOTIFY_OBJ_TYPE_DETACHED) {
                 spin_unlock(&conn->lock);
                 srcu_read_unlock(&fsnotify_mark_srcu, idx);
                 return NULL;
@@ -646,16 +645,16 @@ struct fsnotify_mark *fsnotify_find_mark(
         return NULL;
 }
 
-/* Clear any marks in a group with given type */
+/* Clear any marks in a group with given type mask */
 void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
-                                   unsigned int type)
+                                   unsigned int type_mask)
 {
         struct fsnotify_mark *lmark, *mark;
         LIST_HEAD(to_free);
         struct list_head *head = &to_free;
 
         /* Skip selection step if we want to clear all marks. */
-        if (type == FSNOTIFY_OBJ_ALL_TYPES) {
+        if (type_mask == FSNOTIFY_OBJ_ALL_TYPES_MASK) {
                 head = &group->marks_list;
                 goto clear;
         }
@@ -670,7 +669,7 @@ void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
          */
         mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING);
         list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) {
-                if (mark->connector->flags & type)
+                if ((1U << mark->connector->type) & type_mask)
                         list_move(&mark->g_list, &to_free);
         }
         mutex_unlock(&group->mark_mutex);