Commit 73bf12ad authored by Ye Bin's avatar Ye Bin Committed by Theodore Ts'o
Browse files

ext4: test if inode's all dirty pages are submitted to disk 



The commit aa373cf5 ("writeback: stop background/kupdate works from
livelocking other works") introduced an issue where unmounting a filesystem
in a multi-logical-partition scenario could lead to batch file data loss.
This problem was not fixed until the commit d9210989 ("fs/writeback:
bail out if there is no more inodes for IO and queued once"). It took
considerable time to identify the root cause. Additionally, in actual
production environments, we frequently encountered file data loss after
normal system reboots. Therefore, we are adding a check in the inode
release flow to verify whether all dirty pages have been flushed to disk,
in order to determine whether the data loss is caused by a logic issue in
the filesystem code.

Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260303012242.3206465-1-yebin@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent c4a48e9e

fs/ext4/inode.c

+8 −0
Original line number Diff line number Diff line
@@ -186,6 +186,14 @@ void ext4_evict_inode(struct inode *inode) 
	if (EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)

		ext4_evict_ea_inode(inode);

	if (inode->i_nlink) {

		/*

		 * If there's dirty page will lead to data loss, user

		 * could see stale data.

		 */

		if (unlikely(!ext4_emergency_state(inode->i_sb) &&

		    mapping_tagged(&inode->i_data, PAGECACHE_TAG_DIRTY)))

			ext4_warning_inode(inode, "data will be lost");



		truncate_inode_pages_final(&inode->i_data);



		goto no_delete;