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authorJan Steffens <jan.steffens@gmail.com>2011-03-13 19:06:27 +0100
committerJan Steffens <jan.steffens@gmail.com>2011-03-22 19:47:32 +0100
commit174ff59dba8c24f544e354cd43f3b68aea91d265 (patch)
tree08eec872ad89cdb98850082347566a975067f377 /makechrootpkg
parent5434d3991cd51873f987bde49d55948341c09f3e (diff)
Add flock-based locking to chroots
This prevents accidents when chroots are shared between multiple users.
Diffstat (limited to 'makechrootpkg')
-rwxr-xr-xmakechrootpkg23
1 files changed, 23 insertions, 0 deletions
diff --git a/makechrootpkg b/makechrootpkg
index a38a740..1f6f20a 100755
--- a/makechrootpkg
+++ b/makechrootpkg
@@ -105,11 +105,34 @@ if [ ! -d "$chrootdir/root" ]; then
fi
umask 0022
+
+# Lock the chroot we want to use. We'll keep this lock until we exit.
+# Note this is the same FD number as in mkarchroot
+exec 9>"$copydir.lock"
+if ! flock -n 9; then
+ echo -n "locking chroot copy '$copy'..."
+ flock 9
+ echo "done"
+fi
+
if [ ! -d "$copydir" -o "$clean_first" -eq "1" ]; then
+ # Get a read lock on the root chroot to make
+ # sure we don't clone a half-updated chroot
+ exec 8>"$chrootdir/root.lock"
+
+ if ! flock -sn 8; then
+ echo -n "locking clean chroot..."
+ flock -s 8
+ echo "done"
+ fi
+
echo -n 'creating clean working copy...'
mkdir -p "$copydir"
rsync -a --delete -q -W -x "$chrootdir/root/" "$copydir"
echo 'done'
+
+ # Drop the read lock again
+ exec 8>&-
fi
if [ -n "$install_pkg" ]; then