locks: move freeing of leases outside of i_lock

There was only one place where we still could free a file_lock while
holding the i_lock -- lease_modify. Add a new list_head argument to the
lm_change operation, pass in a private list when calling it, and fix
those callers to dispose of the list once the lock has been dropped.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9a6d56154dd5..f419f718e447 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -873,7 +873,7 @@ struct lock_manager_operations {
         void (*lm_notify)(struct file_lock *);  /* unblock callback */
         int (*lm_grant)(struct file_lock *, int);
         void (*lm_break)(struct file_lock *);
-        int (*lm_change)(struct file_lock **, int);
+        int (*lm_change)(struct file_lock **, int, struct list_head *);
         void (*lm_setup)(struct file_lock *, void **);
 };
 
@@ -985,7 +985,7 @@ extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int t
 extern void lease_get_mtime(struct inode *, struct timespec *time);
 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
 extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
-extern int lease_modify(struct file_lock **, int);
+extern int lease_modify(struct file_lock **, int, struct list_head *);
 #else /* !CONFIG_FILE_LOCKING */
 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
                               struct flock __user *user)
@@ -1112,7 +1112,8 @@ static inline int vfs_setlease(struct file *filp, long arg,
         return -EINVAL;
 }
 
-static inline int lease_modify(struct file_lock **before, int arg)
+static inline int lease_modify(struct file_lock **before, int arg,
+                               struct list_head *dispose)
 {
         return -EINVAL;
 }