diff options
| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-07-28 02:29:12 -0700 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-09-21 14:11:16 -0700 |
| commit | 4f71d28e090f62689f2b48ff25200120a68e07b6 (patch) | |
| tree | ef6e7144f15435fbfbd03070371f2ff43263599f /tools/perf/scripts/python/netdev-times.py | |
| parent | 8af6d9311d8beb57310d2a51d8ed876dc19f0b5d (diff) | |
f2fs: don't need to wait for node writes for atomic write
We have a node chain to serialize node block writes, so if any IOs for
node block writes are reordered, we'll get broken node chain. IOWs,
roll-forward recovery will see all or none node blocks given fsync
mark.
E.g.,
Node chain consists of:
N1 -> N2 -> N3 -> NFSYNC -> N1' -> N2' -> N'FSYNC
Reordered to:
1) N1 -> N2 -> N3 -> N2' -> NFSYNC -> N'FSYNC -> power-cut
2) N1 -> N2 -> N3 -> N1' -> NFSYNC -> power-cut
3) N1 -> N2 -> NFSYNC -> N1' -> N'FSYNC -> N3 -> power-cut
4) N1 -> NFSYNC -> N1' -> N2' -> N'FSYNC -> N3 -> power-cut
Roll-forward recovery can proceed to:
1) N1 -> N2 -> N3 -> NFSYNC -> X
2) N1 -> N2 -> N3 -> NFSYNC -> N1' -> X
3) N1 -> N2 -> N3 -> FSYNC -> N1' -> X
4) N1 -> X
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'tools/perf/scripts/python/netdev-times.py')
0 files changed, 0 insertions, 0 deletions
