1 files changed, 74 insertions, 34 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 801fe7f3628..e57f1724db3 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -21,6 +21,7 @@
 #include <linux/pagemap.h>
 #include <linux/cdev.h>
 #include <linux/bootmem.h>
+#include <linux/inotify.h>
 
 /*
  * This is needed for the following functions:
@@ -202,6 +203,10 @@ void inode_init_once(struct inode *inode)
 	INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
 	spin_lock_init(&inode->i_lock);
 	i_size_ordered_init(inode);
+#ifdef CONFIG_INOTIFY
+	INIT_LIST_HEAD(&inode->inotify_watches);
+	sema_init(&inode->inotify_sem, 1);
+#endif
 }
 
 EXPORT_SYMBOL(inode_init_once);
@@ -282,6 +287,13 @@ static void dispose_list(struct list_head *head)
 		if (inode->i_data.nrpages)
 			truncate_inode_pages(&inode->i_data, 0);
 		clear_inode(inode);
+
+		spin_lock(&inode_lock);
+		hlist_del_init(&inode->i_hash);
+		list_del_init(&inode->i_sb_list);
+		spin_unlock(&inode_lock);
+
+		wake_up_inode(inode);
 		destroy_inode(inode);
 		nr_disposed++;
 	}
@@ -317,8 +329,6 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose)
 		inode = list_entry(tmp, struct inode, i_sb_list);
 		invalidate_inode_buffers(inode);
 		if (!atomic_read(&inode->i_count)) {
-			hlist_del_init(&inode->i_hash);
-			list_del(&inode->i_sb_list);
 			list_move(&inode->i_list, dispose);
 			inode->i_state |= I_FREEING;
 			count++;
@@ -346,6 +356,7 @@ int invalidate_inodes(struct super_block * sb)
 
 	down(&iprune_sem);
 	spin_lock(&inode_lock);
+	inotify_unmount_inodes(&sb->s_inodes);
 	busy = invalidate_list(&sb->s_inodes, &throw_away);
 	spin_unlock(&inode_lock);
 
@@ -439,8 +450,6 @@ static void prune_icache(int nr_to_scan)
 			if (!can_unuse(inode))
 				continue;
 		}
-		hlist_del_init(&inode->i_hash);
-		list_del_init(&inode->i_sb_list);
 		list_move(&inode->i_list, &freeable);
 		inode->i_state |= I_FREEING;
 		nr_pruned++;
@@ -500,7 +509,7 @@ repeat:
 			continue;
 		if (!test(inode, data))
 			continue;
-		if (inode->i_state & (I_FREEING|I_CLEAR)) {
+		if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
 			__wait_on_freeing_inode(inode);
 			goto repeat;
 		}
@@ -525,7 +534,7 @@ repeat:
 			continue;
 		if (inode->i_sb != sb)
 			continue;
-		if (inode->i_state & (I_FREEING|I_CLEAR)) {
+		if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
 			__wait_on_freeing_inode(inode);
 			goto repeat;
 		}
@@ -727,7 +736,7 @@ EXPORT_SYMBOL(iunique);
 struct inode *igrab(struct inode *inode)
 {
 	spin_lock(&inode_lock);
-	if (!(inode->i_state & I_FREEING))
+	if (!(inode->i_state & (I_FREEING|I_WILL_FREE)))
 		__iget(inode);
 	else
 		/*
@@ -748,6 +757,7 @@ EXPORT_SYMBOL(igrab);
  * @head:       the head of the list to search
  * @test:	callback used for comparisons between inodes
  * @data:	opaque data pointer to pass to @test
+ * @wait:	if true wait for the inode to be unlocked, if false do not
  *
  * ifind() searches for the inode specified by @data in the inode
  * cache. This is a generalized version of ifind_fast() for file systems where
@@ -762,7 +772,7 @@ EXPORT_SYMBOL(igrab);
  */
 static inline struct inode *ifind(struct super_block *sb,
 		struct hlist_head *head, int (*test)(struct inode *, void *),
-		void *data)
+		void *data, const int wait)
 {
 	struct inode *inode;
 
@@ -771,7 +781,8 @@ static inline struct inode *ifind(struct super_block *sb,
 	if (inode) {
 		__iget(inode);
 		spin_unlock(&inode_lock);
-		wait_on_inode(inode);
+		if (likely(wait))
+			wait_on_inode(inode);
 		return inode;
 	}
 	spin_unlock(&inode_lock);
@@ -811,7 +822,7 @@ static inline struct inode *ifind_fast(struct super_block *sb,
 }
 
 /**
- * ilookup5 - search for an inode in the inode cache
+ * ilookup5_nowait - search for an inode in the inode cache
  * @sb:		super block of file system to search
  * @hashval:	hash value (usually inode number) to search for
  * @test:	callback used for comparisons between inodes
@@ -823,7 +834,38 @@ static inline struct inode *ifind_fast(struct super_block *sb,
  * identification of an inode.
  *
  * If the inode is in the cache, the inode is returned with an incremented
- * reference count.
+ * reference count.  Note, the inode lock is not waited upon so you have to be
+ * very careful what you do with the returned inode.  You probably should be
+ * using ilookup5() instead.
+ *
+ * Otherwise NULL is returned.
+ *
+ * Note, @test is called with the inode_lock held, so can't sleep.
+ */
+struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
+		int (*test)(struct inode *, void *), void *data)
+{
+	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
+
+	return ifind(sb, head, test, data, 0);
+}
+
+EXPORT_SYMBOL(ilookup5_nowait);
+
+/**
+ * ilookup5 - search for an inode in the inode cache
+ * @sb:		super block of file system to search
+ * @hashval:	hash value (usually inode number) to search for
+ * @test:	callback used for comparisons between inodes
+ * @data:	opaque data pointer to pass to @test
+ *
+ * ilookup5() uses ifind() to search for the inode specified by @hashval and
+ * @data in the inode cache. This is a generalized version of ilookup() for
+ * file systems where the inode number is not sufficient for unique
+ * identification of an inode.
+ *
+ * If the inode is in the cache, the inode lock is waited upon and the inode is
+ * returned with an incremented reference count.
  *
  * Otherwise NULL is returned.
  *
@@ -834,7 +876,7 @@ struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
 {
 	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
 
-	return ifind(sb, head, test, data);
+	return ifind(sb, head, test, data, 1);
 }
 
 EXPORT_SYMBOL(ilookup5);
@@ -891,7 +933,7 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
 	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
 	struct inode *inode;
 
-	inode = ifind(sb, head, test, data);
+	inode = ifind(sb, head, test, data, 1);
 	if (inode)
 		return inode;
 	/*
@@ -1024,17 +1066,21 @@ static void generic_forget_inode(struct inode *inode)
 		if (!(inode->i_state & (I_DIRTY|I_LOCK)))
 			list_move(&inode->i_list, &inode_unused);
 		inodes_stat.nr_unused++;
-		spin_unlock(&inode_lock);
-		if (!sb || (sb->s_flags & MS_ACTIVE))
+		if (!sb || (sb->s_flags & MS_ACTIVE)) {
+			spin_unlock(&inode_lock);
 			return;
+		}
+		inode->i_state |= I_WILL_FREE;
+		spin_unlock(&inode_lock);
 		write_inode_now(inode, 1);
 		spin_lock(&inode_lock);
+		inode->i_state &= ~I_WILL_FREE;
 		inodes_stat.nr_unused--;
 		hlist_del_init(&inode->i_hash);
 	}
 	list_del_init(&inode->i_list);
 	list_del_init(&inode->i_sb_list);
-	inode->i_state|=I_FREEING;
+	inode->i_state |= I_FREEING;
 	inodes_stat.nr_inodes--;
 	spin_unlock(&inode_lock);
 	if (inode->i_data.nrpages)
@@ -1048,7 +1094,7 @@ static void generic_forget_inode(struct inode *inode)
  * inode when the usage count drops to zero, and
  * i_nlink is zero.
  */
-static void generic_drop_inode(struct inode *inode)
+void generic_drop_inode(struct inode *inode)
 {
 	if (!inode->i_nlink)
 		generic_delete_inode(inode);
@@ -1056,6 +1102,8 @@ static void generic_drop_inode(struct inode *inode)
 		generic_forget_inode(inode);
 }
 
+EXPORT_SYMBOL_GPL(generic_drop_inode);
+
 /*
  * Called when we're dropping the last reference
  * to an inode. 
@@ -1238,29 +1286,21 @@ int inode_wait(void *word)
 }
 
 /*
- * If we try to find an inode in the inode hash while it is being deleted, we
- * have to wait until the filesystem completes its deletion before reporting
- * that it isn't found.  This is because iget will immediately call
- * ->read_inode, and we want to be sure that evidence of the deletion is found
- * by ->read_inode.
+ * If we try to find an inode in the inode hash while it is being
+ * deleted, we have to wait until the filesystem completes its
+ * deletion before reporting that it isn't found.  This function waits
+ * until the deletion _might_ have completed.  Callers are responsible
+ * to recheck inode state.
+ *
+ * It doesn't matter if I_LOCK is not set initially, a call to
+ * wake_up_inode() after removing from the hash list will DTRT.
+ *
  * This is called with inode_lock held.
  */
 static void __wait_on_freeing_inode(struct inode *inode)
 {
 	wait_queue_head_t *wq;
 	DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK);
-
-	/*
-	 * I_FREEING and I_CLEAR are cleared in process context under
-	 * inode_lock, so we have to give the tasks who would clear them
-	 * a chance to run and acquire inode_lock.
-	 */
-	if (!(inode->i_state & I_LOCK)) {
-		spin_unlock(&inode_lock);
-		yield();
-		spin_lock(&inode_lock);
-		return;
-	}
 	wq = bit_waitqueue(&inode->i_state, __I_LOCK);
 	prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
 	spin_unlock(&inode_lock);