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>

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
@@ -478,6 +478,49 @@ 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);