fsnotify: add super block object type

Add the infrastructure to attach a mark to a super_block struct
and detach all attached marks when super block is destroyed.

This is going to be used by fanotify backend to setup super block
marks.

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

5 files changed, 28 insertions, 2 deletions

diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index 86fcf5814279..25385e336ac7 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -131,6 +131,11 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 
 		seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
 			   mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
+	} else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_SB) {
+		struct super_block *sb = fsnotify_conn_sb(mark->connector);
+
+		seq_printf(m, "fanotify sdev:%x mflags:%x mask:%x ignored_mask:%x\n",
+			   sb->s_dev, mflags, mark->mask, mark->ignored_mask);
 	}
 }
 
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index ababdbfab537..2971803d151c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -48,7 +48,7 @@ void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
  * Called during unmount with no locks held, so needs to be safe against
  * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
  */
-void fsnotify_unmount_inodes(struct super_block *sb)
+static void fsnotify_unmount_inodes(struct super_block *sb)
 {
 	struct inode *inode, *iput_inode = NULL;
 
@@ -98,6 +98,12 @@ void fsnotify_unmount_inodes(struct super_block *sb)
 		iput(iput_inode);
 }
 
+void fsnotify_sb_delete(struct super_block *sb)
+{
+	fsnotify_unmount_inodes(sb);
+	fsnotify_clear_marks_by_sb(sb);
+}
+
 /*
  * Given an inode, first check if we care what happens to our children.  Inotify
  * and dnotify both tell their parents about events.  If we care about any event
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 7902653dd577..5a00121fb219 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -21,6 +21,12 @@ static inline struct mount *fsnotify_conn_mount(
 	return container_of(conn->obj, struct mount, mnt_fsnotify_marks);
 }
 
+static inline struct super_block *fsnotify_conn_sb(
+				struct fsnotify_mark_connector *conn)
+{
+	return container_of(conn->obj, struct super_block, s_fsnotify_marks);
+}
+
 /* destroy all events sitting in this groups notification queue */
 extern void fsnotify_flush_notify(struct fsnotify_group *group);
 
@@ -43,6 +49,11 @@ static inline void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
 {
 	fsnotify_destroy_marks(&real_mount(mnt)->mnt_fsnotify_marks);
 }
+/* run the list of all marks associated with sb and destroy them */
+static inline void fsnotify_clear_marks_by_sb(struct super_block *sb)
+{
+	fsnotify_destroy_marks(&sb->s_fsnotify_marks);
+}
 /* Wait until all marks queued for destruction are destroyed */
 extern void fsnotify_wait_marks_destroyed(void);
 
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 59cdb27826de..b5172ccb2e60 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -115,6 +115,8 @@ static __u32 *fsnotify_conn_mask_p(struct fsnotify_mark_connector *conn)
 		return &fsnotify_conn_inode(conn)->i_fsnotify_mask;
 	else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT)
 		return &fsnotify_conn_mount(conn)->mnt_fsnotify_mask;
+	else if (conn->type == FSNOTIFY_OBJ_TYPE_SB)
+		return &fsnotify_conn_sb(conn)->s_fsnotify_mask;
 	return NULL;
 }
 
@@ -192,6 +194,8 @@ static struct inode *fsnotify_detach_connector_from_object(
 		inode->i_fsnotify_mask = 0;
 	} else if (conn->type == FSNOTIFY_OBJ_TYPE_VFSMOUNT) {
 		fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
+	} else if (conn->type == FSNOTIFY_OBJ_TYPE_SB) {
+		fsnotify_conn_sb(conn)->s_fsnotify_mask = 0;
 	}
 
 	rcu_assign_pointer(*(conn->obj), NULL);
diff --git a/fs/super.c b/fs/super.c
index f3a8c008e164..ca53a08497ed 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -442,7 +442,7 @@ void generic_shutdown_super(struct super_block *sb)
 		sync_filesystem(sb);
 		sb->s_flags &= ~SB_ACTIVE;
 
-		fsnotify_unmount_inodes(sb);
+		fsnotify_sb_delete(sb);
 		cgroup_writeback_umount();
 
 		evict_inodes(sb);