From: Alberto Leiva Popper <ydahhrk@gmail.com>
Date: Fri, 6 Dec 2024 19:41:05 +0000 (-0300)
Subject: Clear the cache after a crash
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0880f8eac3d35e576a2c1a2cb588424ab4b3e1b;p=thirdparty%2FFORT-validator.git

Clear the cache after a crash

There are many ways in which a mismatching cache index can cause erratic
behavior that's hard to detect. Since the index is written at the end of
the validation cycle, crashing at any point between a cache refresh and
the index write results in a misindexed cache.

Deleting the index after loading it seems to be a reliable way to force
Fort to reset the cache after a crash.

Terminating signals are still a problem, though.
---

diff --git a/src/cache.c b/src/cache.c
index 2b89f740..f6b81583 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -487,6 +487,25 @@ load_index_file(void)
 
 	json_decref(root);
 	pr_op_debug(INDEX_FILE " loaded.");
+
+	/*
+	 * There are many ways in which a mismatching cache index can cause
+	 * erratic behavior that's hard to detect. Since the index is written at
+	 * the end of the validation cycle, crashing at any point between a
+	 * cache refresh and the index write results in a misindexed cache.
+	 *
+	 * Deleting the index right after loading it seems to be a simple and
+	 * reliable way to force Fort to reset the cache after a crash.
+	 * (Recovering with an empty cache is safer than with a misindexed one.)
+	 */
+	error = file_rm_f(INDEX_FILE);
+	if (error)
+		pr_op_warn("Unable to delete " INDEX_FILE ": %s. "
+		    "This means Fort might not recover properly after a crash. "
+		    "If Fort crashes for some reason, "
+		    "please clear the cache manually before restarting.",
+		    strerror(error));
+
 	return 0;
 
 fail:	json_decref(root);
diff --git a/src/file.c b/src/file.c
index 970de0ed..81387a64 100644
--- a/src/file.c
+++ b/src/file.c
@@ -180,6 +180,8 @@ file_rm_f(char const *path)
 {
 	int error;
 
+	pr_op_debug("rm -f %s", path);
+
 	if (remove(path) < 0) {
 		error = errno;
 		if (error != ENOENT)