From: Artem Bityutskiy Subject: [PATCHv3 0/4] ext4: stop using write_supers and s_dirt Date: Tue, 3 Jul 2012 15:00:06 +0300 Message-ID: <1341316810-22598-1-git-send-email-dedekind1@gmail.com> Cc: Jan Kara , Linux Kernel Maling List , Ext4 Mailing List , Linux FS Maling List To: Theodore Tso Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org This patch-set makes ext4 file-system stop using the VFS '->write_supers()' call-back and the '->s_dirt' superblock field because I plan to remove them once all users are gone. Like the other similar patch-sets, we switch to a delayed job for writing out the superblock instead of using the 's_dirt' flag. Additionally, this patch-set includes several clean-ups. Tested with xfstests. And thanks to Jan Kara for the help! Reminder: The goal is to get rid of the 'sync_supers()' kernel thread. This kernel thread wakes up every 5 seconds (by default) and calls '->write_super()' for all mounted file-systems. And the bad thing is that this is done even if all the superblocks are clean. Moreover, many file-systems do not even need this end they do not register the '->write_super()' method at all (e.g., btrfs). So 'sync_supers()' most often just generates useless wake-ups and wastes power. I am trying to make all file-systems independent of '->write_super()' and plan to remove 'sync_supers()' and '->write_super()' completely once there are no more users. ====== Overall status: 1. ext4: patches submitted, https://lkml.org/lkml/2012/4/2/111 2. exofs: patch submitted, https://lkml.org/lkml/2012/6/4/211 3. udf: patch submitted, sits in Jan Kara's tree: https://lkml.org/lkml/2012/6/4/233 git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs for_testing 4. affs: patches submitted, sit in Al Viro's tree: https://lkml.org/lkml/2012/6/6/400 git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs for-next 5. hfs: patches submitted, sit Andrew Morton's tree http://lkml.org/lkml/2012/6/12/82 6. hfsplus: patches submitted, sit in Andre Morton's tree: https://lkml.org/lkml/2012/6/13/195 7. ext2: done, see commit f72cf5e223a28d3b3ea7dc9e40464fd534e359e8 8. vfat: done, see commit 78491189ddb6d84d4a4abae992ed891a236d0263 9. jffs2: done, see commit 208b14e507c00ff7f108e1a388dd3d8cc805a443 10. reiserfs: done, see commit 033369d1af1264abc23bea2e174aa47cdd212f6f TODO: sysv, ufs ====== fs/ext4/ext4.h | 10 +--------- fs/ext4/ext4_jbd2.c | 2 +- fs/ext4/file.c | 14 +++++++++++++- fs/ext4/ialloc.c | 2 -- fs/ext4/mballoc.c | 2 -- fs/ext4/super.c | 15 ++------------- 6 files changed, 17 insertions(+), 28 deletions(-) Thanks, Artem.