linux

iv/linux

History

Konstantin Khlebnikov 8c85e455f7 ovl: skip overlayfs superblocks at global sync

[ Upstream commit 32b1924b210a70dcacdf65abd687c5ef86a67541 ]

Stacked filesystems like overlayfs has no own writeback, but they have to
forward syncfs() requests to backend for keeping data integrity.

During global sync() each overlayfs instance calls method ->sync_fs() for
backend although it itself is in global list of superblocks too.  As a
result one syscall sync() could write one superblock several times and send
multiple disk barriers.

This patch adds flag SB_I_SKIP_SYNC into sb->sb_iflags to avoid that.

Reported-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of: b836c4d29f27 ("ima: detect changes to the backing overlay file")
Signed-off-by: Sasha Levin <sashal@kernel.org>

2023-12-08 08:44:27 +01:00

copy_up.c

overlayfs: set ctime when setting mtime and atime

2023-10-25 11:53:23 +02:00

dir.c

ovl: Use ovl mounter's fsuid and fsgid in ovl_link()

2023-01-18 11:41:43 +01:00

export.c

ovl: drop WARN_ON() dentry is NULL in ovl_encode_fh()

2022-08-25 11:17:23 +02:00

file.c

ovl: fix deadlock in splice write