This is version 2 of the patch-set which makes FAT file-system stop using the VFS '->write_super()' method for writing out the FSINFO block. The fist version can be found here: http://lkml.org/lkml/2012/4/11/147 Comparing to v1, this patch takes a completely different approach. Instead of using a delayed job, we introduce a special inode for the FSINFO block, mark it as dirty when needed, and use generic inode write-back mechanisms to write the FSINFO block via '->write_inode()'. I think this is much cleaner. Let me recap why I am doing this, and the current status of this exercises. The final 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, some 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. The '->write_supers()' method is mostly used by baroque file-systems like hfs, udf, etc. Modern file-systems like btrfs and xfs do not use it. This justifies removing this stuff from VFS completely and make every FS self-manage own superblock. Tested with xfstests. Note: in the past I was trying to upstream patches which optimized 'sync_super()', but Al Viro wanted me to kill it completely instead, which I am trying to do now, see http://lkml.org/lkml/2010/7/22/96 ====== Overall status: 1. ext4: patches submitted, waiting for reply from Ted Ts'o: https://lkml.org/lkml/2012/4/2/111 2. ext2: patches are in the ext2 tree maintained by Jan Kara: git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git for_next However, one patch is still not there: http://www.spinics.net/lists/linux-ext4/msg31492.html TODO: affs, exofs, hfs, hfsplus, jffs2, reiserfs, sysv, udf, ufs ====== fs/fat/fat.h | 1 + fs/fat/fatent.c | 22 +++++++++++++----- fs/fat/inode.c | 54 ++++++++++++++++++++------------------------- include/linux/msdos_fs.h | 3 +- 4 files changed, 43 insertions(+), 37 deletions(-) Thanks, Artem. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
