Document why we need to sort paths while it's still fresh in my
memory.
Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
src/security/security_manager.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/security/security_manager.c b/src/security/security_manager.c
index c205c3bf17..ade2c96141 100644
--- a/src/security/security_manager.c
+++ b/src/security/security_manager.c
@@ -1289,7 +1289,12 @@ virSecurityManagerMetadataLock(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
if (VIR_ALLOC_N(fds, npaths) < 0)
return NULL;
- /* Sort paths to lock in order to avoid deadlocks. */
+ /* Sort paths to lock in order to avoid deadlocks with other
+ * processes. For instance, if one process wants to lock
+ * paths A B and there's another that is trying to lock them
+ * in reversed order a deadlock might occur. But if we sort
+ * the paths alphabetically then both processes will try lock
+ * paths in the same order and thus no deadlock can occur. */
qsort(paths, npaths, sizeof(*paths), cmpstringp);
for (i = 0; i < npaths; i++) {
--
2.21.0
--
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