Sorry for the delay in reply. Confidence in stable posix implementations could come from:
- hardlink backups being the default for nearly 10 years before the previously mentioned patch disabled them after a series of bug reports coming exclusively from Windows users. - generally more dependencies on hardlinks on such systems by different tools which make cache coherency bugs (theory) like issue 4546 less likely. Getting a repro for this bug has been tough. Do you have any ideas for alternative directions here? Excerpts from Augie Fackler's message of 2017-02-14 10:39:00 -0500: > On Tue, Feb 14, 2017 at 01:31:02AM -0800, Jeroen Vaelen wrote: > > # HG changeset patch > > # User Jeroen Vaelen <jer...@fb.com> > > # Date 1487064458 28800 > > # Tue Feb 14 01:27:38 2017 -0800 > > # Node ID c7fb7ac39a12c8683518bb7db7e1a93346e017e0 > > # Parent a0e3d808690d57d1c9dff840e0b8ee099526397b > > transaction: enable hardlink backups for non-windows systems > > > > 07a92bbd02e5 disabled hardlink backups entirely because they can cause > > trouble > > with CIFS on Windows (see issue 4546). This changeset limits that > > restriction > > to Windows systems. Ideally we check for CIFS, because e.g. NTFS does > > support > > hardlinks. But this at least gives us cheaper transactional backups for > > posix, > > which is a step forward. > > I'm hesitant to take this because as of 10.12 macOS is pushing people > towards CIFS instead of AFP, so this issue feels more likely to come > up there. Also, isn't it possible to mount CIFS volumes in the > filesystem space on Linux? Do we have any reason for confidence this > is only a problem in the Windows CIFS client, and not a problem in the > server? > > Thanks! > > > > > Note: the test changes were originally introduced in 07a92bbd02e5. > > > > diff --git a/mercurial/util.py b/mercurial/util.py > > --- a/mercurial/util.py > > +++ b/mercurial/util.py > > @@ -1084,9 +1084,9 @@ > > if checkambig: > > oldstat = checkambig and filestat(dest) > > unlink(dest) > > - # hardlinks are problematic on CIFS, quietly ignore this flag > > - # until we find a way to work around it cleanly (issue4546) > > - if False and hardlink: > > + # quietly ignore the hardlink flag on Windows due to CIFS limitations > > + # (see discussion on issue 4546) > > + if hardlink and pycompat.osname != 'nt': > > try: > > oslink(src, dest) > > return > > diff --git a/tests/test-hardlinks.t b/tests/test-hardlinks.t > > --- a/tests/test-hardlinks.t > > +++ b/tests/test-hardlinks.t > > @@ -166,7 +166,7 @@ > > 1 r2/.hg/store/00manifest.i > > 1 r2/.hg/store/data/d1/f2.i > > 2 r2/.hg/store/data/f1.i > > - 1 r2/.hg/store/fncache > > + 2 r2/.hg/store/fncache > > > > $ hg -R r2 verify > > checking changesets > > @@ -191,7 +191,7 @@ > > 1 r2/.hg/store/00manifest.i > > 1 r2/.hg/store/data/d1/f2.i > > 1 r2/.hg/store/data/f1.i > > - 1 r2/.hg/store/fncache > > + 2 r2/.hg/store/fncache > > > > > > $ cd r3 > > https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
