[PATCH] fsnotify_name/inoderemove

The patch below unhooks fsnotify from vfs_unlink & vfs_rmdir.  It
introduces two new fsnotify calls, that are hooked in at the dcache
level.  This not only more closely matches how the VFS layer works, it
also avoids the problem with locking and inode lifetimes.

The two functions are

 - fsnotify_nameremove -- called when a directory entry is going away.
   It notifies the PARENT of the deletion.  This is called from
   d_delete().

 - inoderemove -- called when the files inode itself is going away.  It
   notifies the inode that is being deleted.  This is called from
   dentry_iput().

Signed-off-by: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/dcache.c

@@ -19,6 +19,7 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
+#include <linux/fsnotify.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/smp_lock.h>
@@ -101,6 +102,7 @@ static inline void dentry_iput(struct dentry * dentry)
 		list_del_init(&dentry->d_alias);
 		spin_unlock(&dentry->d_lock);
 		spin_unlock(&dcache_lock);
+		fsnotify_inoderemove(inode);
 		if (dentry->d_op && dentry->d_op->d_iput)
 			dentry->d_op->d_iput(dentry, inode);
 		else
@@ -1165,13 +1167,16 @@ int d_validate(struct dentry *dentry, struct dentry *dparent)
 
 void d_delete(struct dentry * dentry)
 {
+	int isdir = 0;
 	/*
 	 * Are we the only user?
 	 */
 	spin_lock(&dcache_lock);
 	spin_lock(&dentry->d_lock);
+	isdir = S_ISDIR(dentry->d_inode->i_mode);
 	if (atomic_read(&dentry->d_count) == 1) {
 		dentry_iput(dentry);
+		fsnotify_nameremove(dentry, isdir);
 		return;
 	}
 
@@ -1180,6 +1185,8 @@ void d_delete(struct dentry * dentry)
 
 	spin_unlock(&dentry->d_lock);
 	spin_unlock(&dcache_lock);
+
+	fsnotify_nameremove(dentry, isdir);
 }
 
 static void __d_rehash(struct dentry * entry, struct hlist_head *list)

fs/namei.c

@@ -1802,7 +1802,6 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
 	up(&dentry->d_inode->i_sem);
 	if (!error) {
 		d_delete(dentry);
-		fsnotify_rmdir(dentry, dentry->d_inode, dir);
 	}
 	dput(dentry);
 
@@ -1874,9 +1873,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
 
 	/* We don't d_delete() NFS sillyrenamed files--they still exist. */
 	if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
-		struct inode *inode = dentry->d_inode;
 		d_delete(dentry);
-		fsnotify_unlink(dentry, inode, dir);
 	}
 
 	return error;

include/linux/fsnotify.h

@@ -67,6 +67,26 @@ static inline void fsnotify_rmdir(struct dentry *dentry, struct inode *inode,
 	inotify_inode_is_dead(inode);
 }
 
+/*
+ * fsnotify_nameremove - a filename was removed from a directory
+ */
+static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
+{
+	if (isdir)
+		isdir = IN_ISDIR;
+	dnotify_parent(dentry, DN_DELETE);
+	inotify_dentry_parent_queue_event(dentry, IN_DELETE|isdir, 0, dentry->d_name.name);
+}
+
+/*
+ * fsnotify_inoderemove - an inode is going away
+ */
+static inline void fsnotify_inoderemove(struct inode *inode)
+{
+	inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL);
+	inotify_inode_is_dead(inode);
+}
+
 /*
  * fsnotify_create - 'name' was linked in
  */