From 2dd54aa236f28ed221f38ca3d0ad6d58c3d69d54 Mon Sep 17 00:00:00 2001
From: DualFroz <me@dualfroz.com>
Date: Sat, 12 Sep 2026 19:42:30 +0200
Subject: [PATCH] test: cover bytesEqual

---
 user/fstest.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 user/fstest.c

diff --git a/user/fstest.c b/user/fstest.c
new file mode 100644
index 0000000..78059f0
--- /dev/null
+++ b/user/fstest.c
@@ -0,0 +1,150 @@
+#include "ulib.h"
+#include "fs.h"
+
+/*
+ * Exercises the persistent SFS filesystem (sfs.h/sfs.c) through the exact
+ * same syscall path a real userspace program would use: open/write/read/
+ * close/mkdir/getdents/unlink on paths under "/mnt", which vfs.c dispatches
+ * to sfs.c instead of the kmalloc-based tmpfs tree. Proves the full stack
+ * (syscall -> vfs -> sfs -> real block I/O on the same ATA disk /dev/disk0
+ * uses) works end to end, not just the in-kernel sfs.c unit tests.
+ */
+
+static int bytesEqual(const char* a, const char* b, unsigned long n)
+{
+    for (unsigned long i = 0; i < n; i++)
+        if (a[i] != b[i])
+            return 0;
+    return 1;
+}
+
+int main(void)
+{
+    print("fstest: start, pid=");
+    printDec(userGetpid());
+    print("\n");
+
+    /* Nested directory creation. */
+    if (userMkdir("/mnt/app") != 0) {
+        print("fstest: FAIL mkdir /mnt/app\n");
+        return 1;
+    }
+    if (userMkdir("/mnt/app/logs") != 0) {
+        print("fstest: FAIL mkdir /mnt/app/logs\n");
+        return 1;
+    }
+
+    /* Create + write + close, then reopen with a fresh fd to prove the data
+       lives past the writer's own fd, not just in that fd's local state. */
+    const char* payload = "frostbyte fstest payload line one\n";
+    unsigned long payloadLen = stringLength(payload);
+
+    int wfd = (int)userOpen("/mnt/app/logs/boot.log", oReadWrite | oCreate);
+    if (wfd < 0) {
+        print("fstest: FAIL open for create\n");
+        return 1;
+    }
+    if (userWrite(wfd, payload, payloadLen) != (long)payloadLen) {
+        print("fstest: FAIL short write\n");
+        return 1;
+    }
+    userClose(wfd);
+
+    FbStat st;
+    if (userStat("/mnt/app/logs/boot.log", &st) != 0 || st.size != payloadLen) {
+        print("fstest: FAIL stat size mismatch\n");
+        return 1;
+    }
+
+    int rfd = (int)userOpen("/mnt/app/logs/boot.log", oReadOnly);
+    if (rfd < 0) {
+        print("fstest: FAIL reopen\n");
+        return 1;
+    }
+    char back[128];
+    long got = userRead(rfd, back, sizeof(back));
+    if (got != (long)payloadLen || !bytesEqual(back, payload, payloadLen)) {
+        print("fstest: FAIL reopen round-trip mismatch\n");
+        return 1;
+    }
+    userClose(rfd);
+    print("fstest: create/write/reopen/read round-trip ok\n");
+
+    /* Append across two separate open() calls: growth must pick up where
+       the previous session's data ended. */
+    int afd = (int)userOpen("/mnt/app/logs/boot.log", oReadWrite | oAppend);
+    if (afd < 0) {
+        print("fstest: FAIL open for append\n");
+        return 1;
+    }
+    const char* more = "line two\n";
+    unsigned long moreLen = stringLength(more);
+    if (userWrite(afd, more, moreLen) != (long)moreLen) {
+        print("fstest: FAIL append write\n");
+        return 1;
+    }
+    userClose(afd);
+
+    if (userStat("/mnt/app/logs/boot.log", &st) != 0 || st.size != payloadLen + moreLen) {
+        print("fstest: FAIL stat after append\n");
+        return 1;
+    }
+    print("fstest: append across reopen ok\n");
+
+    /* A second, unrelated file in the same directory, to exercise readdir
+       against more than one entry. */
+    int cfd = (int)userOpen("/mnt/app/logs/counters.txt", oReadWrite | oCreate);
+    if (cfd < 0) {
+        print("fstest: FAIL create second file\n");
+        return 1;
+    }
+    userWrite(cfd, "0", 1);
+    userClose(cfd);
+
+    int dfd = (int)userOpen("/mnt/app/logs", oReadOnly);
+    if (dfd < 0) {
+        print("fstest: FAIL open dir for listing\n");
+        return 1;
+    }
+    FbDirent entries[8];
+    long entCount = userGetdents(dfd, entries, sizeof(entries));
+    userClose(dfd);
+    if (entCount != 2 * (long)sizeof(FbDirent)) {
+        print("fstest: FAIL readdir entry count\n");
+        return 1;
+    }
+    int sawBoot = 0, sawCounters = 0;
+    for (int i = 0; i < 2; i++) {
+        if (entries[i].type != fsTypeFile) {
+            print("fstest: FAIL readdir entry type\n");
+            return 1;
+        }
+        if (bytesEqual(entries[i].name, "boot.log", 9))
+            sawBoot = 1;
+        if (bytesEqual(entries[i].name, "counters.txt", 13))
+            sawCounters = 1;
+    }
+    if (!sawBoot || !sawCounters) {
+        print("fstest: FAIL readdir missing an expected entry\n");
+        return 1;
+    }
+    print("fstest: readdir lists both files ok\n");
+
+    /* Unlink one, verify it is gone and its sibling survives. */
+    if (userUnlink("/mnt/app/logs/counters.txt") != 0) {
+        print("fstest: FAIL unlink counters.txt\n");
+        return 1;
+    }
+    if (userStat("/mnt/app/logs/counters.txt", &st) == 0) {
+        print("fstest: FAIL unlinked file still stat-able\n");
+        return 1;
+    }
+    if (userStat("/mnt/app/logs/boot.log", &st) != 0) {
+        print("fstest: FAIL sibling disappeared after unlink\n");
+        return 1;
+    }
+    print("fstest: unlink ok, sibling survives\n");
+
+    print("fstest: done\n");
+    return 0;
+}