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Commit d2dcd908 authored by Prasad Joshi's avatar Prasad Joshi
Browse files

logfs: destroy the reserved inodes while unmounting 



We were assuming that the evict_inode() would never be called on
reserved inodes. However, (after the commit 8e22c1a4 logfs: get rid
of magical inodes) while unmounting the file system, in put_super, we
call iput() on all of the reserved inodes.

The following simple test used to cause a kernel panic on LogFS:

1. Mount a LogFS file system on /mnt

2. Create a file
   $ touch /mnt/a

3. Try to unmount the FS
   $ umount /mnt

The simple fix would be to drop the assumption and properly destroy
the reserved inodes.

Signed-off-by: default avatarPrasad Joshi <prasadjoshi.linux@gmail.com>
parent dd775ae2

fs/logfs/inode.c

+16 −0
Original line number Diff line number Diff line
@@ -156,10 +156,26 @@ static void __logfs_destroy_inode(struct inode *inode) 
	call_rcu(&inode->i_rcu, logfs_i_callback);

}



static void __logfs_destroy_meta_inode(struct inode *inode)

{

	struct logfs_inode *li = logfs_inode(inode);

	BUG_ON(li->li_block);

	call_rcu(&inode->i_rcu, logfs_i_callback);

}



static void logfs_destroy_inode(struct inode *inode)

{

	struct logfs_inode *li = logfs_inode(inode);



	if (inode->i_ino < LOGFS_RESERVED_INOS) {

		/*

		 * The reserved inodes are never destroyed unless we are in

		 * unmont path.

		 */

		__logfs_destroy_meta_inode(inode);

		return;

	}



	BUG_ON(list_empty(&li->li_freeing_list));

	spin_lock(&logfs_inode_lock);

	li->li_refcount--;

fs/logfs/readwrite.c

+0 −1
Original line number Diff line number Diff line
@@ -2189,7 +2189,6 @@ void logfs_evict_inode(struct inode *inode) 
		return;

	}



	BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS);

	page = inode_to_page(inode);

	BUG_ON(!page); /* FIXME: Use emergency page */

	logfs_put_write_page(page);

fs/logfs/segment.c

+1 −1
Original line number Diff line number Diff line
@@ -886,7 +886,7 @@ static struct logfs_area *alloc_area(struct super_block *sb) 


static void map_invalidatepage(struct page *page, unsigned long l)

{

	BUG();

	return;

}



static int map_releasepage(struct page *page, gfp_t g)