[patch] prevent-concurrent-unmap_mapping_range fix (backported to 2.6.32.x)

2.6.32.33_mm-prevent-concurrent-unmap_mapping_range-on-same-inode.patch (text/plain), 4.75 KB, created by RumpletonBongworth on 2011-03-19 04:26:06 UTC

diff -urp a/fs/inode.c b/fs/inode.c
--- a/fs/inode.c	2009-12-03 03:51:21.000000000 +0000
+++ b/fs/inode.c	2011-03-19 04:09:18.249124833 +0000
@@ -256,6 +256,19 @@ void destroy_inode(struct inode *inode)
 		kmem_cache_free(inode_cachep, (inode));
 }
 
+void address_space_init_once(struct address_space *mapping)
+{
+	memset(mapping, 0, sizeof(*mapping));
+	INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC);
+	spin_lock_init(&mapping->tree_lock);
+	spin_lock_init(&mapping->i_mmap_lock);
+	INIT_LIST_HEAD(&mapping->private_list);
+	spin_lock_init(&mapping->private_lock);
+	INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap);
+	INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
+	mutex_init(&mapping->unmap_mutex);
+}
+
 /*
  * These are initializations that only need to be done
  * once, because the fields are idempotent across use
@@ -267,13 +280,7 @@ void inode_init_once(struct inode *inode
 	INIT_HLIST_NODE(&inode->i_hash);
 	INIT_LIST_HEAD(&inode->i_dentry);
 	INIT_LIST_HEAD(&inode->i_devices);
-	INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
-	spin_lock_init(&inode->i_data.tree_lock);
-	spin_lock_init(&inode->i_data.i_mmap_lock);
-	INIT_LIST_HEAD(&inode->i_data.private_list);
-	spin_lock_init(&inode->i_data.private_lock);
-	INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
-	INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
+	address_space_init_once(&inode->i_data);
 	i_size_ordered_init(inode);
 #ifdef CONFIG_INOTIFY
 	INIT_LIST_HEAD(&inode->inotify_watches);
diff -urp a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
--- a/fs/nilfs2/btnode.c	2009-12-03 03:51:21.000000000 +0000
+++ b/fs/nilfs2/btnode.c	2011-03-19 04:10:09.013124741 +0000
@@ -34,19 +34,6 @@
 #include "btnode.h"
 
 
-void nilfs_btnode_cache_init_once(struct address_space *btnc)
-{
-	memset(btnc, 0, sizeof(*btnc));
-	INIT_RADIX_TREE(&btnc->page_tree, GFP_ATOMIC);
-	spin_lock_init(&btnc->tree_lock);
-	INIT_LIST_HEAD(&btnc->private_list);
-	spin_lock_init(&btnc->private_lock);
-
-	spin_lock_init(&btnc->i_mmap_lock);
-	INIT_RAW_PRIO_TREE_ROOT(&btnc->i_mmap);
-	INIT_LIST_HEAD(&btnc->i_mmap_nonlinear);
-}
-
 static const struct address_space_operations def_btnode_aops = {
 	.sync_page		= block_sync_page,
 };
diff -urp a/fs/nilfs2/btnode.h b/fs/nilfs2/btnode.h
--- a/fs/nilfs2/btnode.h	2009-12-03 03:51:21.000000000 +0000
+++ b/fs/nilfs2/btnode.h	2011-03-19 04:10:22.820622908 +0000
@@ -37,7 +37,6 @@ struct nilfs_btnode_chkey_ctxt {
 	struct buffer_head *newbh;
 };
 
-void nilfs_btnode_cache_init_once(struct address_space *);
 void nilfs_btnode_cache_init(struct address_space *, struct backing_dev_info *);
 void nilfs_btnode_cache_clear(struct address_space *);
 int nilfs_btnode_submit_block(struct address_space *, __u64, sector_t,
diff -urp a/fs/nilfs2/super.c b/fs/nilfs2/super.c
--- a/fs/nilfs2/super.c	2011-03-19 03:58:57.000000000 +0000
+++ b/fs/nilfs2/super.c	2011-03-19 04:12:21.501142492 +0000
@@ -166,7 +166,7 @@ static void init_once(void *obj)
 #ifdef CONFIG_NILFS_XATTR
 	init_rwsem(&ii->xattr_sem);
 #endif
-	nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
+	address_space_init_once(&ii->i_btnode_cache);
 	ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
 	inode_init_once(&ii->vfs_inode);
 }
diff -urp a/include/linux/fs.h b/include/linux/fs.h
--- a/include/linux/fs.h	2011-03-19 03:59:20.000000000 +0000
+++ b/include/linux/fs.h	2011-03-19 04:14:14.061141568 +0000
@@ -640,6 +640,7 @@ struct address_space {
 	spinlock_t		private_lock;	/* for use by the address_space */
 	struct list_head	private_list;	/* ditto */
 	struct address_space	*assoc_mapping;	/* ditto */
+	struct mutex		unmap_mutex;	/* to protect unmapping */
 } __attribute__((aligned(sizeof(long))));
 	/*
 	 * On most architectures that alignment is already the case; but
@@ -2163,6 +2164,7 @@ extern loff_t vfs_llseek(struct file *fi
 
 extern int inode_init_always(struct super_block *, struct inode *);
 extern void inode_init_once(struct inode *);
+extern void address_space_init_once(struct address_space *mapping);
 extern void inode_add_to_lists(struct super_block *, struct inode *);
 extern void iput(struct inode *);
 extern struct inode * igrab(struct inode *);
diff -urp a/mm/memory.c b/mm/memory.c
--- a/mm/memory.c	2011-03-19 03:59:20.000000000 +0000
+++ b/mm/memory.c	2011-03-19 04:15:49.332622739 +0000
@@ -2668,6 +2668,7 @@ void unmap_mapping_range(struct address_
 		details.last_index = ULONG_MAX;
 	details.i_mmap_lock = &mapping->i_mmap_lock;
 
+	mutex_lock(&mapping->unmap_mutex);
 	spin_lock(&mapping->i_mmap_lock);
 
 	/* Protect against endless unmapping loops */
@@ -2684,6 +2685,7 @@ void unmap_mapping_range(struct address_
 	if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
 		unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
 	spin_unlock(&mapping->i_mmap_lock);
+	mutex_unlock(&mapping->unmap_mutex);
 }
 EXPORT_SYMBOL(unmap_mapping_range);