1 files changed, 39 insertions, 5 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 7ef18fc656c2..469086b9f99b 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -305,7 +305,6 @@ static void nilfs_transaction_lock(struct super_block *sb,
 	ti->ti_count = 0;
 	ti->ti_save = cur_ti;
 	ti->ti_magic = NILFS_TI_MAGIC;
-	INIT_LIST_HEAD(&ti->ti_garbage);
 	current->journal_info = ti;
 
 	for (;;) {
@@ -332,8 +331,6 @@ static void nilfs_transaction_unlock(struct super_block *sb)
 
 	up_write(&nilfs->ns_segctor_sem);
 	current->journal_info = ti->ti_save;
-	if (!list_empty(&ti->ti_garbage))
-		nilfs_dispose_list(nilfs, &ti->ti_garbage, 0);
 }
 
 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
@@ -746,6 +743,15 @@ static void nilfs_dispose_list(struct the_nilfs *nilfs,
 	}
 }
 
+static void nilfs_iput_work_func(struct work_struct *work)
+{
+	struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
+						 sc_iput_work);
+	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
+
+	nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
+}
+
 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
 				     struct nilfs_root *root)
 {
@@ -1900,8 +1906,8 @@ static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
 					     struct the_nilfs *nilfs)
 {
-	struct nilfs_transaction_info *ti = current->journal_info;
 	struct nilfs_inode_info *ii, *n;
+	int defer_iput = false;
 
 	spin_lock(&nilfs->ns_inode_lock);
 	list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
@@ -1912,9 +1918,24 @@ static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
 		clear_bit(NILFS_I_BUSY, &ii->i_state);
 		brelse(ii->i_bh);
 		ii->i_bh = NULL;
-		list_move_tail(&ii->i_dirty, &ti->ti_garbage);
+		list_del_init(&ii->i_dirty);
+		if (!ii->vfs_inode.i_nlink) {
+			/*
+			 * Defer calling iput() to avoid a deadlock
+			 * over I_SYNC flag for inodes with i_nlink == 0
+			 */
+			list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
+			defer_iput = true;
+		} else {
+			spin_unlock(&nilfs->ns_inode_lock);
+			iput(&ii->vfs_inode);
+			spin_lock(&nilfs->ns_inode_lock);
+		}
 	}
 	spin_unlock(&nilfs->ns_inode_lock);
+
+	if (defer_iput)
+		schedule_work(&sci->sc_iput_work);
 }
 
 /*
@@ -2583,6 +2604,8 @@ static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
 	INIT_LIST_HEAD(&sci->sc_segbufs);
 	INIT_LIST_HEAD(&sci->sc_write_logs);
 	INIT_LIST_HEAD(&sci->sc_gc_inodes);
+	INIT_LIST_HEAD(&sci->sc_iput_queue);
+	INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
 	init_timer(&sci->sc_timer);
 
 	sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
@@ -2609,6 +2632,8 @@ static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
 		ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
 		nilfs_transaction_unlock(sci->sc_super);
 
+		flush_work(&sci->sc_iput_work);
+
 	} while (ret && retrycount-- > 0);
 }
 
@@ -2633,6 +2658,9 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
 		|| sci->sc_seq_request != sci->sc_seq_done);
 	spin_unlock(&sci->sc_state_lock);
 
+	if (flush_work(&sci->sc_iput_work))
+		flag = true;
+
 	if (flag || !nilfs_segctor_confirm(sci))
 		nilfs_segctor_write_out(sci);
 
@@ -2642,6 +2670,12 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
 		nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
 	}
 
+	if (!list_empty(&sci->sc_iput_queue)) {
+		nilfs_warning(sci->sc_super, __func__,
+			      "iput queue is not empty\n");
+		nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
+	}
+
 	WARN_ON(!list_empty(&sci->sc_segbufs));
 	WARN_ON(!list_empty(&sci->sc_write_logs));