[patch 26/27] fs: icache protect inode state

[npiggin]

Protect i_hash, i_sb_list etc members with i_lock.
---
 fs/hugetlbfs/inode.c |   14 +++++++++-----
 fs/inode.c           |   30 +++++++++++++++++++++++++++---
 2 files changed, 36 insertions(+), 8 deletions(-)

Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c
+++ linux-2.6/fs/inode.c
@@ -337,12 +337,14 @@ static void dispose_list(struct list_hea
 		clear_inode(inode);
 
 		spin_lock(&inode_lock);
+		spin_lock(&sb_inode_list_lock);
+		spin_lock(&inode->i_lock);
 		spin_lock(&inode_hash_lock);
 		hlist_del_init(&inode->i_hash);
 		spin_unlock(&inode_hash_lock);
-		spin_lock(&sb_inode_list_lock);
 		list_del_init(&inode->i_sb_list);
 		spin_unlock(&sb_inode_list_lock);
+		spin_unlock(&inode->i_lock);
 		spin_unlock(&inode_lock);
 
 		wake_up_inode(inode);
@@ -640,7 +642,6 @@ __inode_add_to_lists(struct super_block
 			struct inode *inode)
 {
 	atomic_inc(&inodes_stat.nr_inodes);
-	spin_lock(&sb_inode_list_lock);
 	list_add(&inode->i_sb_list, &sb->s_inodes);
 	spin_unlock(&sb_inode_list_lock);
 	spin_lock(&wb_inode_list_lock);
@@ -670,7 +671,10 @@ void inode_add_to_lists(struct super_blo
 	struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino);
 
 	spin_lock(&inode_lock);
+	spin_lock(&sb_inode_list_lock);
+	spin_lock(&inode->i_lock);
 	__inode_add_to_lists(sb, head, inode);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 EXPORT_SYMBOL_GPL(inode_add_to_lists);
@@ -702,9 +706,12 @@ struct inode *new_inode(struct super_blo
 	inode = alloc_inode(sb);
 	if (inode) {
 		spin_lock(&inode_lock);
+		spin_lock(&sb_inode_list_lock);
+		spin_lock(&inode->i_lock);
 		inode->i_ino = ++last_ino;
 		inode->i_state = 0;
 		__inode_add_to_lists(sb, NULL, inode);
+		spin_unlock(&inode->i_lock);
 		spin_unlock(&inode_lock);
 	}
 	return inode;
@@ -759,11 +766,14 @@ static struct inode * get_new_inode(stru
 		/* We released the lock, so.. */
 		old = find_inode(sb, head, test, data);
 		if (!old) {
+			spin_lock(&sb_inode_list_lock);
+			spin_lock(&inode->i_lock);
 			if (set(inode, data))
 				goto set_failed;
 
 			inode->i_state = I_LOCK|I_NEW;
 			__inode_add_to_lists(sb, head, inode);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 
 			/* Return the locked inode with I_NEW set, the
@@ -809,9 +819,12 @@ static struct inode * get_new_inode_fast
 		/* We released the lock, so.. */
 		old = find_inode_fast(sb, head, ino);
 		if (!old) {
+			spin_lock(&sb_inode_list_lock);
+			spin_lock(&inode->i_lock);
 			inode->i_ino = ino;
 			inode->i_state = I_LOCK|I_NEW;
 			__inode_add_to_lists(sb, head, inode);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 
 			/* Return the locked inode with I_NEW set, the
@@ -1137,9 +1150,11 @@ int insert_inode_locked(struct inode *in
 		spin_lock(&inode_lock);
 		old = find_inode_fast(sb, head, ino);
 		if (likely(!old)) {
+			spin_lock(&inode->i_lock);
 			spin_lock(&inode_hash_lock);
 			hlist_add_head(&inode->i_hash, head);
 			spin_unlock(&inode_hash_lock);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 			return 0;
 		}
@@ -1170,9 +1185,11 @@ int insert_inode_locked4(struct inode *i
 		spin_lock(&inode_lock);
 		old = find_inode(sb, head, test, data);
 		if (likely(!old)) {
+			spin_lock(&inode->i_lock);
 			spin_lock(&inode_hash_lock);
 			hlist_add_head(&inode->i_hash, head);
 			spin_unlock(&inode_hash_lock);
+			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_lock);
 			return 0;
 		}
@@ -1201,10 +1218,13 @@ EXPORT_SYMBOL(insert_inode_locked4);
 void __insert_inode_hash(struct inode *inode, unsigned long hashval)
 {
 	struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
+
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_add_head(&inode->i_hash, head);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 
@@ -1219,9 +1239,11 @@ EXPORT_SYMBOL(__insert_inode_hash);
 void remove_inode_hash(struct inode *inode)
 {
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_del_init(&inode->i_hash);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 }
 
@@ -1270,9 +1292,11 @@ void generic_delete_inode(struct inode *
 		clear_inode(inode);
 	}
 	spin_lock(&inode_lock);
+	spin_lock(&inode->i_lock);
 	spin_lock(&inode_hash_lock);
 	hlist_del_init(&inode->i_hash);
 	spin_unlock(&inode_hash_lock);
+	spin_unlock(&inode->i_lock);
 	spin_unlock(&inode_lock);
 	wake_up_inode(inode);
 	BUG_ON(inode->i_state != I_CLEAR);
@@ -1309,10 +1333,10 @@ static void generic_forget_inode(struct
 		spin_lock(&inode->i_lock);
 		WARN_ON(inode->i_state & I_NEW);
 		inode->i_state &= ~I_WILL_FREE;
-		atomic_dec(&inodes_stat.nr_unused);
 		spin_lock(&inode_hash_lock);
 		hlist_del_init(&inode->i_hash);
 		spin_unlock(&inode_hash_lock);
+		atomic_dec(&inodes_stat.nr_unused);
 	}
 	spin_lock(&wb_inode_list_lock);
 	list_del_init(&inode->i_list);
Index: linux-2.6/fs/hugetlbfs/inode.c
===================================================================
--- linux-2.6.orig/fs/hugetlbfs/inode.c
+++ linux-2.6/fs/hugetlbfs/inode.c
@@ -400,12 +400,15 @@ static void hugetlbfs_forget_inode(struc
 		}
 		atomic_inc(&inodes_stat.nr_unused);
 		if (!sb || (sb->s_flags & MS_ACTIVE)) {
+			spin_unlock(&inode->i_lock);
+			spin_unlock(&sb_inode_list_lock);
 			spin_unlock(&inode_lock);
 			return;
 		}
-		spin_lock(&inode->i_lock);
+		WARN_ON(inode->i_state & I_NEW);
 		inode->i_state |= I_WILL_FREE;
 		spin_unlock(&inode->i_lock);
+		spin_unlock(&sb_inode_list_lock);
 		spin_unlock(&inode_lock);
 		/*
 		 * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK
@@ -413,27 +416,28 @@ static void hugetlbfs_forget_inode(struc
 		 */
 		write_inode_now(inode, 1);
 		spin_lock(&inode_lock);
+		spin_lock(&sb_inode_list_lock);
 		spin_lock(&inode->i_lock);
+		WARN_ON(inode->i_state & I_NEW);
 		inode->i_state &= ~I_WILL_FREE;
 		spin_lock(&inode_hash_lock);
 		hlist_del_init(&inode->i_hash);
 		spin_unlock(&inode_hash_lock);
-		spin_unlock(&inode->i_lock);
 		atomic_dec(&inodes_stat.nr_unused);
 	}
 	spin_lock(&wb_inode_list_lock);
 	list_del_init(&inode->i_list);
 	spin_unlock(&wb_inode_list_lock);
-	spin_lock(&sb_inode_list_lock);
 	list_del_init(&inode->i_sb_list);
 	spin_unlock(&sb_inode_list_lock);
-	spin_lock(&inode->i_lock);
+	WARN_ON(inode->i_state & I_NEW);
 	inode->i_state |= I_FREEING;
 	spin_unlock(&inode->i_lock);
-	atomic_dec(&inodes_stat.nr_unused);
 	spin_unlock(&inode_lock);
+	atomic_dec(&inodes_stat.nr_unused);
 	truncate_hugepages(inode, 0);
 	clear_inode(inode);
+	/* XXX: why no wake_up_inode? */
 	destroy_inode(inode);
 }
 


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