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author | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-07-28 02:29:12 -0700 |
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committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-07-31 16:48:34 -0700 |
commit | b6a245eb34cd935f48235e1160d8b7539b228e8e (patch) | |
tree | 0e3043f3a255a41a0cd838aca265a832aef66f18 /fs/f2fs/file.c | |
parent | dc6b20551044a05cd4d8ad2356a6bd888570f52a (diff) | |
download | linux-stable-b6a245eb34cd935f48235e1160d8b7539b228e8e.tar.gz linux-stable-b6a245eb34cd935f48235e1160d8b7539b228e8e.tar.bz2 linux-stable-b6a245eb34cd935f48235e1160d8b7539b228e8e.zip |
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 'fs/f2fs/file.c')
-rw-r--r-- | fs/f2fs/file.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index a0413c951458..0246d19d96c3 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -274,9 +274,19 @@ sync_nodes: goto sync_nodes; } - ret = wait_on_node_pages_writeback(sbi, ino); - if (ret) - goto out; + /* + * If it's atomic_write, it's just fine to keep write ordering. So + * here we don't need to wait for node write completion, since we use + * node chain which serializes node blocks. If one of node writes are + * reordered, we can see simply broken chain, resulting in stopping + * roll-forward recovery. It means we'll recover all or none node blocks + * given fsync mark. + */ + if (!atomic) { + ret = wait_on_node_pages_writeback(sbi, ino); + if (ret) + goto out; + } /* once recovery info is written, don't need to tack this */ remove_ino_entry(sbi, ino, APPEND_INO); |