From 61cc9f34d208f838db3a8935e224aade6038ffdc Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 9 Dec 2019 23:57:33 +0100
Subject: [PATCH] Remove UserLock self-lock check
This is no longer needed since we're not using POSIX locks anymore.
---
src/libstore/build.cc | 75 +++++++++++++------------------------------
1 file changed, 22 insertions(+), 53 deletions(-)
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 31011cd7c..69649162e 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -499,12 +499,6 @@ void handleDiffHook(uid_t uid, uid_t gid, Path tryA, Path tryB, Path drvPath, Pa
class UserLock
{
private:
- /* POSIX locks suck. If we have a lock on a file, and we open and
- close that file again (without closing the original file
- descriptor), we lose the lock. So we have to be *very* careful
- not to open a lock file on which we are holding a lock. */
- static Sync<PathSet> lockedPaths_;
-
Path fnUserLock;
AutoCloseFD fdUserLock;
@@ -515,7 +509,6 @@ private:
public:
UserLock();
- ~UserLock();
void kill();
@@ -529,9 +522,6 @@ public:
};
-Sync<PathSet> UserLock::lockedPaths_;
-
-
UserLock::UserLock()
{
assert(settings.buildUsersGroup != "");
@@ -568,47 +558,34 @@ UserLock::UserLock()
fnUserLock = (format("%1%/userpool/%2%") % settings.nixStateDir % pw->pw_uid).str();
- {
- auto lockedPaths(lockedPaths_.lock());
- if (!lockedPaths->insert(fnUserLock).second)
- /* We already have a lock on this one. */
- continue;
- }
+ AutoCloseFD fd = open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600);
+ if (!fd)
+ throw SysError(format("opening user lock '%1%'") % fnUserLock);
- try {
-
- AutoCloseFD fd = open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600);
- if (!fd)
- throw SysError(format("opening user lock '%1%'") % fnUserLock);
+ if (lockFile(fd.get(), ltWrite, false)) {
+ fdUserLock = std::move(fd);
+ user = i;
+ uid = pw->pw_uid;
- if (lockFile(fd.get(), ltWrite, false)) {
- fdUserLock = std::move(fd);
- user = i;
- uid = pw->pw_uid;
-
- /* Sanity check... */
- if (uid == getuid() || uid == geteuid())
- throw Error(format("the Nix user should not be a member of '%1%'")
- % settings.buildUsersGroup);
+ /* Sanity check... */
+ if (uid == getuid() || uid == geteuid())
+ throw Error(format("the Nix user should not be a member of '%1%'")
+ % settings.buildUsersGroup);
#if __linux__
- /* Get the list of supplementary groups of this build user. This
- is usually either empty or contains a group such as "kvm". */
- supplementaryGIDs.resize(10);
- int ngroups = supplementaryGIDs.size();
- int err = getgrouplist(pw->pw_name, pw->pw_gid,
- supplementaryGIDs.data(), &ngroups);
- if (err == -1)
- throw Error(format("failed to get list of supplementary groups for '%1%'") % pw->pw_name);
-
- supplementaryGIDs.resize(ngroups);
+ /* Get the list of supplementary groups of this build user. This
+ is usually either empty or contains a group such as "kvm". */
+ supplementaryGIDs.resize(10);
+ int ngroups = supplementaryGIDs.size();
+ int err = getgrouplist(pw->pw_name, pw->pw_gid,
+ supplementaryGIDs.data(), &ngroups);
+ if (err == -1)
+ throw Error(format("failed to get list of supplementary groups for '%1%'") % pw->pw_name);
+
+ supplementaryGIDs.resize(ngroups);
#endif
- return;
- }
-
- } catch (...) {
- lockedPaths_.lock()->erase(fnUserLock);
+ return;
}
}
@@ -618,14 +595,6 @@ UserLock::UserLock()
}
-UserLock::~UserLock()
-{
- auto lockedPaths(lockedPaths_.lock());
- auto erased = lockedPaths->erase(fnUserLock);
- assert(erased);
-}
-
-
void UserLock::kill()
{
killUser(uid);
--
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