From 63997e98a3be68d7cec806d22bf9b02b2e1daabb Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 25 Oct 2010 20:49:35 -0400
Subject: [PATCH] split invalidate_inodes()

Pull removal of fsnotify marks into generic_shutdown_super().
Split umount-time work into a new function - evict_inodes().
Make sure that invalidate_inodes() will be able to cope with
I_FREEING once we change locking in iput().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/inode.c             | 46 ++++++++++++++++++++++++++++++++++++++++--
 fs/internal.h          |  1 +
 fs/notify/inode_mark.c |  2 ++
 fs/super.c             |  8 ++++----
 4 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index f6b3b52f1278..a6d60682f0fd 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -477,6 +477,49 @@ static void dispose_list(struct list_head *head)
 	}
 }
 
+/**
+ * evict_inodes	- evict all evictable inodes for a superblock
+ * @sb:		superblock to operate on
+ *
+ * Make sure that no inodes with zero refcount are retained.  This is
+ * called by superblock shutdown after having MS_ACTIVE flag removed,
+ * so any inode reaching zero refcount during or after that call will
+ * be immediately evicted.
+ */
+void evict_inodes(struct super_block *sb)
+{
+	struct inode *inode, *next;
+	LIST_HEAD(dispose);
+
+	down_write(&iprune_sem);
+
+	spin_lock(&inode_lock);
+	list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
+		if (atomic_read(&inode->i_count))
+			continue;
+
+		if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
+			WARN_ON(1);
+			continue;
+		}
+
+		inode->i_state |= I_FREEING;
+
+		/*
+		 * Move the inode off the IO lists and LRU once I_FREEING is
+		 * set so that it won't get moved back on there if it is dirty.
+		 */
+		list_move(&inode->i_lru, &dispose);
+		list_del_init(&inode->i_wb_list);
+		if (!(inode->i_state & (I_DIRTY | I_SYNC)))
+			percpu_counter_dec(&nr_inodes_unused);
+	}
+	spin_unlock(&inode_lock);
+
+	dispose_list(&dispose);
+	up_write(&iprune_sem);
+}
+
 /**
  * invalidate_inodes	- attempt to free all inodes on a superblock
  * @sb:		superblock to operate on
@@ -493,9 +536,8 @@ int invalidate_inodes(struct super_block *sb)
 	down_write(&iprune_sem);
 
 	spin_lock(&inode_lock);
-	fsnotify_unmount_inodes(&sb->s_inodes);
 	list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
-		if (inode->i_state & I_NEW)
+		if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE))
 			continue;
 		if (atomic_read(&inode->i_count)) {
 			busy = 1;
diff --git a/fs/internal.h b/fs/internal.h
index 4cc67eb6ed56..ebad3b90752d 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -106,4 +106,5 @@ extern void release_open_intent(struct nameidata *);
  * inode.c
  */
 extern int get_nr_dirty_inodes(void);
+extern int evict_inodes(struct super_block *);
 extern int invalidate_inodes(struct super_block *);
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 33297c005060..21ed10660b80 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -240,6 +240,7 @@ void fsnotify_unmount_inodes(struct list_head *list)
 {
 	struct inode *inode, *next_i, *need_iput = NULL;
 
+	spin_lock(&inode_lock);
 	list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
 		struct inode *need_iput_tmp;
 
@@ -297,4 +298,5 @@ void fsnotify_unmount_inodes(struct list_head *list)
 
 		spin_lock(&inode_lock);
 	}
+	spin_unlock(&inode_lock);
 }
diff --git a/fs/super.c b/fs/super.c
index 8819e3a7ff20..b9c9869165db 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -273,14 +273,14 @@ void generic_shutdown_super(struct super_block *sb)
 		get_fs_excl();
 		sb->s_flags &= ~MS_ACTIVE;
 
-		/* bad name - it should be evict_inodes() */
-		invalidate_inodes(sb);
+		fsnotify_unmount_inodes(&sb->s_inodes);
+
+		evict_inodes(sb);
 
 		if (sop->put_super)
 			sop->put_super(sb);
 
-		/* Forget any remaining inodes */
-		if (invalidate_inodes(sb)) {
+		if (!list_empty(&sb->s_inodes)) {
 			printk("VFS: Busy inodes after unmount of %s. "
 			   "Self-destruct in 5 seconds.  Have a nice day...\n",
 			   sb->s_id);