[PATCH 4.15 138/163] Btrfs: fix btrfs_evict_inode to handle abnormal inodes correctly

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liu Bo <bo.li.liu@xxxxxxxxxx>

commit e8f1bc1493855e32b7a2a019decc3c353d94daf6 upstream.

This regression is introduced in
commit 3d48d9810de4 ("btrfs: Handle uninitialised inode eviction").

There are two problems,

a) it is ->destroy_inode() that does the final free on inode, not
   ->evict_inode(),
b) clear_inode() must be called before ->evict_inode() returns.

This could end up hitting BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
in evict() because I_CLEAR is set in clear_inode().

Fixes: commit 3d48d9810de4 ("btrfs: Handle uninitialised inode eviction")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.7-rc6+
Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Reviewed-by: Josef Bacik <jbacik@xxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/btrfs/inode.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5266,7 +5266,7 @@ void btrfs_evict_inode(struct inode *ino
 	trace_btrfs_inode_evict(inode);
 
 	if (!root) {
-		kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+		clear_inode(inode);
 		return;
 	}