test: strengthen tests for sfsTest

src/sfsTest.c

@@ -468,3 +468,159 @@ KTEST(sfsPersistsMtimeAndCtimeAcrossUnmountRemount)
         return;
     KT_EQ(t, sfsWriteAt(f, 0, "persisted", 9), 9);
 
+    uint64 mtimeBefore = sfsMtimeOf(f);
+    uint64 ctimeBefore = sfsCtimeOf(f);
+    KT_GT(t, mtimeBefore, 0);
+
+    sfsUnmount();
+    KT_TRUE(t, sfsMount());
+
+    int32 reloaded = sfsLookup("timepersist.txt");
+    KT_EQ(t, reloaded, f);
+    KT_EQ(t, sfsMtimeOf(reloaded), mtimeBefore);
+    KT_EQ(t, sfsCtimeOf(reloaded), ctimeBefore);
+}
+
+/* Real chmod(2) owner rwx bits (fs.h's fsModeOwner*): createNode stamps a
+   type-based default (a file gets fsModeDefaultFile, a directory gets
+   fsModeDefaultDir), sfsChmod overwrites it and bumps ctime like any other
+   metadata-only mutation (sfsLink's linkCount bump does the same, see
+   above), and sfsModeOf/sfsChmod on an invalid inode number fail the same
+   way sfsSizeOf/sfsTypeOf already do for one. */
+KTEST(sfsModeDefaultsByTypeAndChmodBumpsCtime)
+{
+    if (!KT_TRUE(t, sfsFormat()))
+        return;
+
+    int32 f = sfsCreateFile("modefile.txt");
+    if (!KT_TRUE(t, f > 0))
+        return;
+    KT_EQ(t, sfsModeOf(f), fsModeDefaultFile);
+
+    int32 d = sfsCreateDir("modedir");
+    if (!KT_TRUE(t, d > 0))
+        return;
+    KT_EQ(t, sfsModeOf(d), fsModeDefaultDir);
+
+    uint64 ctimeBefore = sfsCtimeOf(f);
+    int64 before = rtcNow();
+    KT_TRUE(t, sfsChmod(f, 0400));
+    int64 after = rtcNow();
+
+    KT_EQ(t, sfsModeOf(f), 0400u);
+    KT_GE(t, sfsCtimeOf(f), ctimeBefore);
+    KT_GE(t, sfsCtimeOf(f), before);
+    KT_LE(t, sfsCtimeOf(f), after);
+
+    KT_EQ(t, sfsModeOf(-1), 0u);
+    KT_EQ(t, sfsModeOf(9999), 0u);
+    KT_FALSE(t, sfsChmod(-1, 0644));
+    KT_FALSE(t, sfsChmod(9999, 0644));
+}
+
+/* Same real point as sfsPersistsMtimeAndCtimeAcrossUnmountRemount above,
+   applied to mode: sfsUnmount() drops every in-memory structure, so an
+   exact match after sfsMount() proves the chmod'd value genuinely lives on
+   disk inside the inode, not in some cache that happens to survive. */
+KTEST(sfsPersistsModeAcrossUnmountRemount)
+{
+    if (!KT_TRUE(t, sfsFormat()))
+        return;
+
+    int32 f = sfsCreateFile("modepersist.txt");
+    if (!KT_TRUE(t, f > 0))
+        return;
+    KT_TRUE(t, sfsChmod(f, 0400));
+
+    sfsUnmount();
+    KT_TRUE(t, sfsMount());
+
+    int32 reloaded = sfsLookup("modepersist.txt");
+    KT_EQ(t, reloaded, f);
+    KT_EQ(t, sfsModeOf(reloaded), 0400u);
+}
+
+/* Real owner identity (fs.h's FbStat.uid, sched.h's currentThreadUid()):
+   createNode stamps every new node -- file, dir, symlink, fifo all go
+   through it, exactly like mtime/ctime already verified sufficient for
+   (FALA 39's own note) -- with whoever is CURRENT at creation time.
+   ktestRunAll always runs as the permanent idle thread (id 0, uid 0), the
+   same context schedTest.c's own uid-default tests already document
+   relying on, so both a freshly created file and the root inode itself
+   (sfsFormat, this test's own sfsFormat() call included) come back
+   root-owned. sfsUidOf on an invalid inode number fails the same way
+   sfsModeOf/sfsSizeOf/sfsTypeOf already do for one. */
+KTEST(sfsCreateNodeStampsCreatorUidAsOwner)
+{
+    if (!KT_TRUE(t, sfsFormat()))
+        return;
+
+    KT_EQU(t, sfsUidOf(sfsRootInode), 0u);
+
+    int32 f = sfsCreateFile("uidfile.txt");
+    if (!KT_TRUE(t, f > 0))
+        return;
+    KT_EQU(t, sfsUidOf(f), 0u);
+
+    int32 d = sfsCreateDir("uiddir");
+    if (!KT_TRUE(t, d > 0))
+        return;
+    KT_EQU(t, sfsUidOf(d), 0u);
+
+    KT_EQU(t, sfsUidOf(-1), 0u);
+    KT_EQU(t, sfsUidOf(9999), 0u);
+}
+
+/* Same real point as sfsPersistsModeAcrossUnmountRemount above, applied to
+   uid: sfsUnmount() drops every in-memory structure, so an exact match
+   after sfsMount() proves ownership genuinely lives on disk inside the
+   inode, not in some cache that happens to survive. */
+KTEST(sfsPersistsUidAcrossUnmountRemount)
+{
+    if (!KT_TRUE(t, sfsFormat()))
+        return;
+
+    int32 f = sfsCreateFile("uidpersist.txt");
+    if (!KT_TRUE(t, f > 0))
+        return;
+    KT_EQU(t, sfsUidOf(f), 0u);
+
+    sfsUnmount();
+    KT_TRUE(t, sfsMount());
+
+    int32 reloaded = sfsLookup("uidpersist.txt");
+    KT_EQ(t, reloaded, f);
+    KT_EQU(t, sfsUidOf(reloaded), 0u);
+}
+
+/* Real chown(2)'s on-disk half (sfsChown): overwrites the inode's owner
+   uid outright and bumps ctime like sfsChmod's own metadata-only mutation
+   does -- same "bump ctime, invalid inode fails the same way" shape as
+   sfsModeDefaultsByTypeAndChmodBumpsCtime above. sfsChown itself has no
+   privilege check (vfsChown, vfs.c, is the real choke point that enforces
+   chown(2)'s root-only rule), so calling it directly here at any uid is
+   deliberately not restricted. */
+KTEST(sfsChownReassignsOwnerAndBumpsCtime)
+{
+    if (!KT_TRUE(t, sfsFormat()))
+        return;
+
+    int32 f = sfsCreateFile("chownfile.txt");
+    if (!KT_TRUE(t, f > 0))
+        return;
+    KT_EQU(t, sfsUidOf(f), 0u);
+
+    uint64 ctimeBefore = sfsCtimeOf(f);
+    int64 before = rtcNow();
+    KT_TRUE(t, sfsChown(f, 9001));
+    int64 after = rtcNow();
+
+    KT_EQU(t, sfsUidOf(f), 9001u);
+    KT_GE(t, sfsCtimeOf(f), ctimeBefore);
+    KT_GE(t, sfsCtimeOf(f), before);
+    KT_LE(t, sfsCtimeOf(f), after);
+
+    KT_FALSE(t, sfsChown(-1, 1000));
+    KT_FALSE(t, sfsChown(9999, 1000));
+}
+