ext4: update c/mtime on truncate up

Commit 3da40c7b0898 ("ext4: only call ext4_truncate when size <= isize")
introduced a bug that c/mtime is not updated on truncate up.

Fix the issue by setting c/mtime explicitly in the truncate up case.

Note that ftruncate(2) is not affected, so you won't see this bug using
truncate(1) and xfs_io(1).

Signed-off-by: Zirong Lang <zorro.lang@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index cecf9aa1081134d255455ee329a4e118b8355216..2442eb065e1961029c2cacc0230ac7b49f03fc67 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4725,6 +4725,14 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                                error = ext4_orphan_add(handle, inode);
                                orphan = 1;
                        }
+                       /*
+                        * Update c/mtime on truncate up, ext4_truncate() will
+                        * update c/mtime in shrink case below
+                        */
+                       if (!shrink) {
+                               inode->i_mtime = ext4_current_time(inode);
+                               inode->i_ctime = inode->i_mtime;
+                       }
                        down_write(&EXT4_I(inode)->i_data_sem);
                        EXT4_I(inode)->i_disksize = attr->ia_size;
                        rc = ext4_mark_inode_dirty(handle, inode);