>From 55bde5feb7aa94812b82de615db4effee12bc196 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 16 Jun 2016 10:22:50 +0200
Subject: [PATCH 1/2] Revert "ext4: remove i_ioend_count"

This reverts commit 600be30a8bc1d405f791e01dbef84679e14529b8.
---
 fs/ext4/ext4.h    | 7 ++++++-
 fs/ext4/inode.c   | 3 +++
 fs/ext4/page-io.c | 4 ++++
 fs/ext4/super.c   | 1 +
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b84aa1ca480a..d64fc259590f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1063,8 +1063,13 @@ struct ext4_inode_info {
 	 * transaction reserved
 	 */
 	struct list_head i_rsv_conversion_list;
-	struct work_struct i_rsv_conversion_work;
+	/*
+	 * Completed IOs that need unwritten extents handling and don't have
+	 * transaction reserved
+	 */
+	atomic_t i_ioend_count;	/* Number of outstanding io_end structs */
 	atomic_t i_unwritten; /* Nr. of inflight conversions pending */
+	struct work_struct i_rsv_conversion_work;
 
 	spinlock_t i_block_reservation_lock;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f7140ca66e3b..cb00e5949bc3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -216,6 +216,7 @@ void ext4_evict_inode(struct inode *inode)
 		}
 		truncate_inode_pages_final(&inode->i_data);
 
+		WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
 		goto no_delete;
 	}
 
@@ -227,6 +228,8 @@ void ext4_evict_inode(struct inode *inode)
 		ext4_begin_ordered_truncate(inode, 0);
 	truncate_inode_pages_final(&inode->i_data);
 
+	WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
+
 	/*
 	 * Protect us against freezing - iput() caller didn't have to have any
 	 * protection against it
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 2a01df9cc1c3..cc5f529e328e 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -129,6 +129,9 @@ static void ext4_release_io_end(ext4_io_end_t *io_end)
 	BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN);
 	WARN_ON(io_end->handle);
 
+	if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count))
+		wake_up_all(ext4_ioend_wq(io_end->inode));
+
 	for (bio = io_end->bio; bio; bio = next_bio) {
 		next_bio = bio->bi_private;
 		ext4_finish_bio(bio);
@@ -253,6 +256,7 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
 {
 	ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags);
 	if (io) {
+		atomic_inc(&EXT4_I(inode)->i_ioend_count);
 		io->inode = inode;
 		INIT_LIST_HEAD(&io->list);
 		atomic_set(&io->count, 1);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3822a5aedc61..221ec29afde6 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -943,6 +943,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	spin_lock_init(&ei->i_completed_io_lock);
 	ei->i_sync_tid = 0;
 	ei->i_datasync_tid = 0;
+	atomic_set(&ei->i_ioend_count, 0);
 	atomic_set(&ei->i_unwritten, 0);
 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-- 
2.6.6