Fix race condition when two processes create the same link in /nix/store/.links

This commit is contained in:
Eelco Dolstra 2012-08-05 18:17:55 -04:00
parent 6763084ae5
commit 108e14bb18

View file

@ -102,11 +102,11 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path)
/* Nope, create a hard link in the links directory. */
makeMutable(path);
MakeImmutable mk1(path);
if (link(path.c_str(), linkPath.c_str()) == -1)
if (link(path.c_str(), linkPath.c_str()) == 0) return;
if (errno != EEXIST)
throw SysError(format("cannot link `%1%' to `%2%'") % linkPath % path);
return;
/* Fall through if another process created linkPath before
we did. */
}
/* Yes! We've seen a file with the same contents. Replace the