The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 82a25b027ca48d7ef197295846b352345853dfa8 Mon Sep 17 00:00:00 2001
From: Jan Kara jack@suse.cz Date: Thu, 23 May 2019 23:07:08 -0400 Subject: [PATCH] ext4: wait for outstanding dio during truncate in nojournal mode
We didn't wait for outstanding direct IO during truncate in nojournal mode (as we skip orphan handling in that case). This can lead to fs corruption or stale data exposure if truncate ends up freeing blocks and these get reallocated before direct IO finishes. Fix the condition determining whether the wait is necessary.
CC: stable@vger.kernel.org Fixes: 1c9114f9c0f1 ("ext4: serialize unlocked dio reads with truncate") Reviewed-by: Ira Weiny ira.weiny@intel.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Theodore Ts'o tytso@mit.edu
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 82298c63ea6d..9bcb7f2b86dd 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5630,20 +5630,17 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) goto err_out; } } - if (!shrink) + if (!shrink) { pagecache_isize_extended(inode, oldsize, inode->i_size); - - /* - * Blocks are going to be removed from the inode. Wait - * for dio in flight. Temporarily disable - * dioread_nolock to prevent livelock. - */ - if (orphan) { - if (!ext4_should_journal_data(inode)) { - inode_dio_wait(inode); - } else - ext4_wait_for_tail_page_commit(inode); + } else { + /* + * Blocks are going to be removed from the inode. Wait + * for dio in flight. + */ + inode_dio_wait(inode); } + if (orphan && ext4_should_journal_data(inode)) + ext4_wait_for_tail_page_commit(inode); down_write(&EXT4_I(inode)->i_mmap_sem);
rc = ext4_break_layouts(inode);