This is an extension of the noop-sync after unrelated write-sync after
desync corner case:
op a state b state
in-sync in-sync
desync(b) in-sync desync
write(a) unsync desync
sync(a) in-sync' desync
sync(b) in-sync in-sync
But instead of explicitly calling lfsr_file_sync, what if you implicitly
triggered sync through something like a write on a file with the
LFS_O_SYNC flag, but not a normal write, a noop write, write(0)?
If the definition of LFS_O_SYNC is taken literally as "lfsr_file_write
and friends implicitly call lfsr_file_sync after every call", then this
should behave just as if lfsr_file_sync had been called, and
unconditionally broadcast the sync. Since this is the simplest
interpretation, I think this is what we should implement.
Added tests, and adopted this behavior. Fortunately this just involves
some small gotos (https://xkcd.com/292):
code stack
before: 33020 2976
after: 33026 (+0.0%) 2976 (+0.0%)
Christopher Haster
4e7a68ff08