s3:smbd: make use of share_mode_entry_prepare_{lock_add,unlock}() in open_{file_ntcre...

s3:smbd: make use of share_mode_entry_prepare_{lock_add,unlock}() in open_{file_ntcreate,directory}()

This gives a nice speed up...

The following test with 256 commections all looping with open/close
on the same inode (share root) is improved drastically:

  smbtorture //127.0.0.1/m -Uroot%test smb2.bench.path-contention-shared \
         --option='torture:bench_path=' \
         --option="torture:timelimit=60" \
         --option="torture:nprocs=256" \
         --option="torture:qdepth=1"

From something like this:

    open[num/s=11536,avslat=0.011450,minlat=0.000039,maxlat=0.052707]
    close[num/s=11534,avslat=0.010878,minlat=0.000022,maxlat=0.052342]

(only this commit with the close part reverted) to:

    open[num/s=12722,avslat=0.009548,minlat=0.000051,maxlat=0.054338]
    close[num/s=12720,avslat=0.010701,minlat=0.000033,maxlat=0.054372]

(with both patches) to:

    open[num/s=37680,avslat=0.003471,minlat=0.000040,maxlat=0.061411]
    close[num/s=37678,avslat=0.003440,minlat=0.000022,maxlat=0.051536]

So we are finally perform similar like we did in Samba 4.12,
which resulted in:

    open[num/s=36846,avslat=0.003574,minlat=0.000043,maxlat=0.020378]
    close[num/s=36844,avslat=0.003552,minlat=0.000026,maxlat=0.020321]

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15125

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>