[PATCH] ext4: deaccount delayed allocations at freeing inode in ext4_evict_inode()

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
	linux-ext4@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
	linux-kernel@vger.kernel.org
Cc: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>,
	Eric Whitney <enwlinux@gmail.com>
Subject: [PATCH] ext4: deaccount delayed allocations at freeing inode in ext4_evict_inode()
Date: Tue, 29 Oct 2019 10:17:28 +0300	[thread overview]
Message-ID: <157233344808.4027.17162642259754563372.stgit@buzz> (raw)

If inode->i_blocks is zero then ext4_evict_inode() skips ext4_truncate().
Delayed allocation extents are freed later in ext4_clear_inode() but this
happens when quota reference is already dropped. This leads to leak of
reserved space in quota block, which disappears after umount-mount.

This seems broken for a long time but worked somehow until recent changes
in delayed allocation.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 fs/ext4/inode.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 516faa280ced..580898145e8f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -293,6 +293,15 @@ void ext4_evict_inode(struct inode *inode)
 				   inode->i_ino, err);
 			goto stop_handle;
 		}
+	} else if (EXT4_I(inode)->i_reserved_data_blocks) {
+		/* Deaccount reserve if inode has only delayed allocations. */
+		err = ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
+		if (err) {
+			ext4_warning(inode->i_sb,
+				     "couldn't remove extents %lu (err %d)",
+				     inode->i_ino, err);
+			goto stop_handle;
+		}
 	}
 
 	/* Remove xattr references. */

