lix/src/libutil/mount.cc
Artemis Tosini 3058029fba
libutil: Add bindPath function from libstore
bindPath/doBind is a useful function in build that is used in several
parts of LocalDerivationGoal. Moving this function makes it easier to
split LocalDerivationGoal implementation between several files.

Change-Id: Ic5a0768479c153c1aa3ed425f12604b20bbf0f42
2024-07-27 19:40:40 +00:00

44 lines
1.1 KiB
C++

#include "mount.hh"
#include "error.hh"
#include "file-system.hh"
#include "logging.hh"
#if __linux__
#include <sys/mount.h>
namespace nix {
void bindPath(const Path & source, const Path & target, bool optional) {
debug("bind mounting '%1%' to '%2%'", source, target);
auto bindMount = [&]() {
if (mount(source.c_str(), target.c_str(), "", MS_BIND | MS_REC, 0) == -1)
throw SysError("bind mount from '%1%' to '%2%' failed", source, target);
};
auto maybeSt = maybeLstat(source);
if (!maybeSt) {
if (optional)
return;
else
throw SysError("getting attributes of path '%1%'", source);
}
auto st = *maybeSt;
if (S_ISDIR(st.st_mode)) {
createDirs(target);
bindMount();
} else if (S_ISLNK(st.st_mode)) {
// Symlinks can (apparently) not be bind-mounted, so just copy it
createDirs(dirOf(target));
copyFile(source, target, {});
} else {
createDirs(dirOf(target));
writeFile(target, "");
bindMount();
}
}
}
#endif