[PATCH] transaction: enable hardlink backups for non-windows systems

[Durham Goode]

On 3/2/17 8:09 AM, Ryan McElroy wrote:
>
>
> On 3/2/17 7:46 AM, Yuya Nishihara wrote:
>> On Wed, 1 Mar 2017 17:55:25 -0800, Jun Wu wrote:
>>> According to
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__bz.mercurial-2Dscm.org_show-5Fbug.cgi-3Fid-3D4546-3A&d=DwIGaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=Jw8rundaE7TbmqBYd1txIQ&m=vjW-XcGbq_x7AbgPtmJ8lHDdDLYljlyx2xvUxSdf4IE&s=6scd8qQkJR-0MXuZo-p47gjTcBa4U3m-ZywPbWfxOKI&e=
>>>
>>>
>>>    Testing with mercurial 3.2 and 3.3 to a Linux samba server worked
>>> without
>>>    issue in the few tests I've done.  This suggests the most likely
>>> cause is
>>>    an NTFS/Windows based file server?
>>>
>>> So I think at least we can have a whitelist (instead of a blacklist)
>>> that
>>> allows Linux to use real hardlinks. Just ignore OS X or Windows for now.
>> She said a Linux samba server had no problem, not a Linux client with
>> Windows
>> server.
>
> Sounds like just changing this is a non-starter then. How about using a
> config option, so people like us can get the perf benefits in places
> where we are not concerned about the possible downsides (because we
> prevent clones onto NFS/CIFS shares, for example)? Would anyone object
> to turning this into an option that defaults to off?

Might be hard to get a config option down to this level, since there's 
no ui object around here, but we could probably move the 'False' value 
to a module level variable so extensions could at least set it to True.