Btrfs: Add delayed iput

iput() can trigger new transactions if we are dropping the
final reference, so calling it in btrfs_commit_transaction
may end up deadlock. This patch adds delayed iput to avoid
the issue.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index a7cac2148c7c..1983c889bb1c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -872,6 +872,9 @@ struct btrfs_fs_info {
         struct list_head dead_roots;
         struct list_head caching_block_groups;
 
+        spinlock_t delayed_iput_lock;
+        struct list_head delayed_iputs;
+
         atomic_t nr_async_submits;
         atomic_t async_submit_draining;
         atomic_t nr_async_bios;
@@ -2301,7 +2304,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
                                struct inode *inode, u64 new_size,
                                u32 min_type);
 
-int btrfs_start_delalloc_inodes(struct btrfs_root *root);
+int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput);
 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
 int btrfs_writepages(struct address_space *mapping,
                      struct writeback_control *wbc);
@@ -2341,6 +2344,8 @@ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
 void btrfs_orphan_cleanup(struct btrfs_root *root);
 int btrfs_cont_expand(struct inode *inode, loff_t size);
 int btrfs_invalidate_inodes(struct btrfs_root *root);
+void btrfs_add_delayed_iput(struct inode *inode);
+void btrfs_run_delayed_iputs(struct btrfs_root *root);
 extern const struct dentry_operations btrfs_dentry_operations;
 
 /* ioctl.c */