fs: add iput_not_last()

Signed-off-by: Mateusz Guzik <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

Author: mjguzik

fs/inode.c

@@ -1967,6 +1967,18 @@ void iput(struct inode *inode)
 }
 EXPORT_SYMBOL(iput);
 
+/**
+ *	iput_not_last	- put an inode assuming this is not the last reference
+ *	@inode: inode to put
+ */
+void iput_not_last(struct inode *inode)
+{
+	VFS_BUG_ON_INODE(atomic_read(&inode->i_count) < 2, inode);
+
+	WARN_ON(atomic_sub_return(1, &inode->i_count) == 0);
+}
+EXPORT_SYMBOL(iput_not_last);
+
 #ifdef CONFIG_BLOCK
 /**
  *	bmap	- find a block number in a file

include/linux/fs.h

@@ -2824,6 +2824,7 @@ extern int current_umask(void);
 
 extern void ihold(struct inode * inode);
 extern void iput(struct inode *);
+void iput_not_last(struct inode *);
 int inode_update_timestamps(struct inode *inode, int flags);
 int generic_update_time(struct inode *, int);