The services db is created as a temporary file that is moved over the
existing file after completion. Thus there is no need to immediately
flush all created db records to the temporary file.
This speeds up creation of the services db by a factor of 500 on my
ZFS based /var/db filesytem (from 110 seconds to 0.235 seconds).
MFC after: 1 week
Similar fix was done for passwd and group operations in r285050. When a
temporary file is created and then renamed to replace official file there
are no checks to make sure data was written to disk and if a power cycle
happens at this time, system can end up with a 0 length file
Approved by: bapt
MFC after: 1 week
Sponsored by: Netgate
Differential Revision: https://reviews.freebsd.org/D2982
In addition to adding missing `static' keywords:
- bin/dd: Pull in `extern.h' to guarantee consistency with source file.
- libexec/rpc.rusersd: Move shared globals into an extern.h.
- libexec/talkd: Move `debug' and `hostname' into extern.h.
- usr.bin/cksum: Put counters in extern.h, as they are used by ckdist/mtree.
- usr.bin/m4: Move `end_result' into extern.h.
- usr.sbin/services_mkdb: Move shared globals into an extern.h.
