Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Chengguang Xu <cgxu519@mykernel.net>
To: miklos@szeredi.hu, jack@suse.cz, amir73il@gmail.com
Cc: linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Chengguang Xu <cgxu519@mykernel.net>
Subject: [RFC PATCH v4 0/9] implement containerized syncfs for overlayfs
Date: Fri, 13 Nov 2020 14:55:46 +0800
Message-ID: <20201113065555.147276-1-cgxu519@mykernel.net> (raw)

Current syncfs(2) syscall on overlayfs just calls sync_filesystem()
on upper_sb to synchronize whole dirty inodes in upper filesystem
regardless of the overlay ownership of the inode. In the use case of
container, when multiple containers using the same underlying upper
filesystem, it has some shortcomings as below.

(1) Performance
Synchronization is probably heavy because it actually syncs unnecessary
inodes for target overlayfs.

(2) Interference
Unplanned synchronization will probably impact IO performance of
unrelated container processes on the other overlayfs.

This series try to implement containerized syncfs for overlayfs so that
only sync target dirty upper inodes which are belong to specific overlayfs
instance. By doing this, it is able to reduce cost of synchronization and
will not seriously impact IO performance of unrelated processes.

v1->v2:
- Mark overlayfs' inode dirty itself instead of adding notification
  mechanism to vfs inode.

v2->v3:
- Introduce overlayfs' extra syncfs wait list to wait target upper inodes
in ->sync_fs.

v3->v4:
- Using wait_sb_inodes() to wait syncing upper inodes.
- Mark overlay inode dirty only when having upper inode and  VM_SHARED
flag in ovl_mmap().
- Check upper i_state after checking upper mmap state
in ovl_write_inode.

Chengguang Xu (9):
  ovl: setup overlayfs' private bdi
  ovl: implement ->writepages operation
  ovl: implement overlayfs' ->evict_inode operation
  ovl: mark overlayfs' inode dirty on modification
  ovl: mark overlayfs' inode dirty on shared mmap
  ovl: implement overlayfs' ->write_inode operation
  ovl: cache dirty overlayfs' inode
  fs: export wait_sb_inodes()
  ovl: implement containerized syncfs for overlayfs

 fs/fs-writeback.c         |  3 +-
 fs/overlayfs/file.c       |  3 ++
 fs/overlayfs/inode.c      | 15 ++++++++++
 fs/overlayfs/overlayfs.h  |  4 +++
 fs/overlayfs/super.c      | 63 ++++++++++++++++++++++++++++++++++++---
 fs/overlayfs/util.c       | 14 +++++++++
 include/linux/writeback.h |  1 +
 7 files changed, 98 insertions(+), 5 deletions(-)

-- 
2.26.2



             reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-13  6:55 Chengguang Xu [this message]
2020-11-13  6:55 ` [RFC PATCH v4 1/9] ovl: setup overlayfs' private bdi Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 2/9] ovl: implement ->writepages operation Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 3/9] ovl: implement overlayfs' ->evict_inode operation Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 4/9] ovl: mark overlayfs' inode dirty on modification Chengguang Xu
2021-04-09 13:45   ` Miklos Szeredi
2021-04-12 11:58     ` Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 5/9] ovl: mark overlayfs' inode dirty on shared mmap Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 6/9] ovl: implement overlayfs' ->write_inode operation Chengguang Xu
2021-04-09 13:49   ` Miklos Szeredi
2021-04-14  6:14     ` Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 7/9] ovl: cache dirty overlayfs' inode Chengguang Xu
2021-04-09 13:50   ` Miklos Szeredi
2021-04-13  2:14     ` Chengguang Xu
2021-04-13  8:43       ` Miklos Szeredi
2021-04-14  5:53         ` Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 8/9] fs: export wait_sb_inodes() Chengguang Xu
2020-11-13  6:55 ` [RFC PATCH v4 9/9] ovl: implement containerized syncfs for overlayfs Chengguang Xu
2021-04-09 13:51   ` Miklos Szeredi
2021-04-12 12:24     ` Chengguang Xu
2021-04-12 14:22       ` Miklos Szeredi
2020-12-04 14:49 ` 回复:[RFC PATCH v4 0/9] " Chengguang Xu
2020-12-04 15:02   ` [RFC " Miklos Szeredi
2020-12-04 16:40   ` 回复:[RFC " Jan Kara

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201113065555.147276-1-cgxu519@mykernel.net \
    --to=cgxu519@mykernel.net \
    --cc=amir73il@gmail.com \
    --cc=jack@suse.cz \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git