From 1eeb12756ba5fb8a4b4802ad3931f99e64ffda2a Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Fri, 26 Jun 2020 01:06:29 -0700
Subject: [PATCH] shlib: add and use clear_stale_ref_locks function

If git is killed during a ref update operation, it may leave behind
a ref lock file.

Add a new clear_stale_ref_locks function to find and remove
any of these stale left-behind *.lock files.

Call clear_stale_ref_locks as part of the "remove_crud" operation
durin gc, part of the cleanup operation when restarting a failed
clone and as part of the cleanup operation before doing a mirror
update.

Since Girocco now makes it a point to (mostly) maintain refs in
a packed state, the check and removal will always be relatively
quick and cheap to do.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
---
 jobd/gc.sh     |  9 ++++++---
 jobd/update.sh |  3 +++
 shlib.sh       | 20 ++++++++++++++++++++
 taskd/clone.sh |  3 +++
 4 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/jobd/gc.sh b/jobd/gc.sh
index c3393f0..58702b7 100755
--- a/jobd/gc.sh
+++ b/jobd/gc.sh
@@ -481,6 +481,9 @@ remove_crud() {
 	# there were a lot of refs.
 	rm -f FETCH_HEAD
 
+	# Remove any stale ref locks
+	clear_stale_ref_locks
+
 	# remove any existing pack_is_complete_test or repack subdirectories
 	# If either exists when this function is called it's crud
 	rm -rf pack_is_complete_test repack objects/pack/repack
@@ -809,15 +812,15 @@ lock_gc
 # At this point, if .allowgc or .gc_failed exists, it's now crud to be removed
 rm -f .allowgc .gc_failed
 
+# Always get rid of crud
+remove_crud
+
 # Ideally we would do this in post-receive, but that would mean duplicating the
 # logic so it's available in the chroot jail and that's highly undesirable
 # Instead, since the first gc will be triggered immediately following the first
 # push, we do the check here as it's quick and harmless if HEAD is already valid
 check_and_set_head || :
 
-# Always get rid of crud
-remove_crud
-
 # Always perform reflogs maintenance
 coalesce_reflogs
 prune_reflogs
diff --git a/jobd/update.sh b/jobd/update.sh
index 2454bda..c46083a 100755
--- a/jobd/update.sh
+++ b/jobd/update.sh
@@ -133,6 +133,9 @@ progress "+ [$proj] update ($(date))"
 # Any pre-existing FETCH_HEAD from a previous fetch, failed or not, is garbage
 rm -f FETCH_HEAD
 
+# Remove any stale ref locks
+clear_stale_ref_locks
+
 # A previous failed update attempt can leave a huge tmp_pack_XXXXXX file behind.
 # Since no pushes are allowed to mirrors, we know that any such files that exist
 # at this point in time are garbage and can be safely deleted, we do not even
diff --git a/shlib.sh b/shlib.sh
index 2de11ae..80a2e00 100644
--- a/shlib.sh
+++ b/shlib.sh
@@ -920,6 +920,26 @@ check_and_set_needsgc() {
 	fi
 }
 
+# current directory must already be set to Git repository
+# remove any existing stale .lock files anywhere in the refs hierarchy
+# mirror .lock files are considered "stale" after 60m whereas push projects
+# need 12h for a .lock file to be considered stale.
+clear_stale_ref_locks() {
+	# Quick sanity check just in case
+	[ -f HEAD ] && [ -s HEAD ] && [ -d objects ] && [ -d refs ] || return 1
+	_stale=60
+	[ ! -e .nofetch ] || _stale=720
+	# Clear any stale top-level ref locks
+	find . -maxdepth 1 -name '*?.lock' -type f -mmin +$_stale -exec rm -f '{}' + >/dev/null 2>&1 || :
+	if [ -d worktrees ]; then
+		# Clear any worktrees stale top-level ref locks
+		find -H worktrees -mindepth 2 -maxdepth 2 -name '*?.lock' -type f -mmin +$_stale -exec rm -f '{}' + >/dev/null 2>&1 || :
+	fi
+	# Clear any stale ref locks within the refs hierarchy itself
+	find -H refs -mindepth 1 -name '*?.lock' -type f -mmin +$_stale -exec rm -f '{}' + >/dev/null 2>&1 || :
+	return 0
+}
+
 # A well-known UTF-8 locale is required for some of the fast-import providers
 # in order to avoid mangling characters.  Ideally we could use "POSIX.UTF-8"
 # but that is not reliably UTF-8 but rather usually US-ASCII.
diff --git a/taskd/clone.sh b/taskd/clone.sh
index 296b696..14e6733 100755
--- a/taskd/clone.sh
+++ b/taskd/clone.sh
@@ -149,6 +149,9 @@ cleanup_failed_clone() {
 	# now garbage to be removed
 	rm -f FETCH_HEAD
 
+	# Remove any stale ref locks
+	clear_stale_ref_locks
+
 	# Remove any left-over svn dir from a previous failed attempt
 	rm -rf svn
 
-- 
2.11.4.GIT