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 nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
alloc.h nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
bmap.c
bmap.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
btnode.c
btnode.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
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 [readdir] convert nilfs2 2013-06-29 12:56:36 +04:00
direct.c
direct.h
export.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
file.c nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() 2014-10-14 02:18:20 +02:00
gcinode.c nilfs2: ensure proper cache clearing for gc-inodes 2012-06-20 14:39:35 -07:00
ifile.c ] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct 2013-07-03 16:08:01 -07:00
ifile.h nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
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 fs/nilfs2: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:04 -08:00
Makefile nilfs2: integrate sysfs support into driver 2014-08-08 15:57:21 -07:00
mdt.c nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption 2013-04-30 17:04:04 -07:00
mdt.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
namei.c fs: encode_fh: return FILEID_INVALID if invalid fid_type 2013-02-26 02:46:10 -05:00
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 nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption 2013-04-30 17:04:04 -07:00
recovery.c nilfs2: drop vmtruncate 2012-12-20 18:40:54 -05:00
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