kernel_optimize_test/fs/nilfs2
Andreas Rohner b9f6614072 nilfs2: improve the performance of fdatasync()
Support for fdatasync() has been implemented in NILFS2 for a long time,
but whenever the corresponding inode is dirty the implementation falls
back to a full-flegded sync().  Since every write operation has to
update the modification time of the file, the inode will almost always
be dirty and fdatasync() will fall back to sync() most of the time.  But
this fallback is only necessary for a change of the file size and not
for a change of the various timestamps.

This patch adds a new flag NILFS_I_INODE_SYNC to differentiate between
those two situations.

 * If it is set the file size was changed and a full sync is necessary.
 * If it is not set then only the timestamps were updated and
   fdatasync() can go ahead.

There is already a similar flag I_DIRTY_DATASYNC on the VFS layer with
the exact same semantics.  Unfortunately it cannot be used directly,
because NILFS2 doesn't implement write_inode() and doesn't clear the VFS
flags when inodes are written out.  So the VFS writeback thread can
clear I_DIRTY_DATASYNC at any time without notifying NILFS2.  So
I_DIRTY_DATASYNC has to be mapped onto NILFS_I_INODE_SYNC in
nilfs_update_inode().

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:20 +02:00
..
alloc.c
alloc.h
bmap.c
bmap.h
btnode.c
btnode.h
btree.c
btree.h
cpfile.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
cpfile.h
dat.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
dat.h
dir.c
direct.c
direct.h
export.h
file.c nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() 2014-10-14 02:18:20 +02:00
gcinode.c
ifile.c
ifile.h
inode.c nilfs2: improve the performance of fdatasync() 2014-10-14 02:18:20 +02:00
ioctl.c nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() 2014-10-14 02:18:20 +02:00
Kconfig
Makefile nilfs2: integrate sysfs support into driver 2014-08-08 15:57:21 -07:00
mdt.c
mdt.h
namei.c
nilfs.h nilfs2: improve the performance of fdatasync() 2014-10-14 02:18:20 +02:00
page.c nilfs2: fix issue with race condition of competition between segments for dirty blocks 2013-09-30 14:31:02 -07:00
page.h
recovery.c
segbuf.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
segbuf.h
segment.c nilfs2: improve the performance of fdatasync() 2014-10-14 02:18:20 +02:00
segment.h
sufile.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
sufile.h nilfs2: add nilfs_sufile_trim_fs to trim clean segs 2014-04-03 16:21:25 -07:00
super.c nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() 2014-10-14 02:18:20 +02:00
sysfs.c nilfs2: integrate sysfs support into driver 2014-08-08 15:57:21 -07:00
sysfs.h nilfs2: add /sys/fs/nilfs2/<device>/mounted_snapshots/<snapshot> group 2014-08-08 15:57:21 -07:00
the_nilfs.c nilfs2: integrate sysfs support into driver 2014-08-08 15:57:21 -07:00
the_nilfs.h nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() 2014-10-14 02:18:20 +02:00