=== DF-2215 FIX VALIDATION (defense-in-depth) ===
=== Fixed dm.ko: SHA256 = 3ed52cca2f6b48a5993c1237d31d42c63f03d9b662410f77b2118ca62bbcdc92 ===
=== Fix compiles, installs, loads; dm operates normally ===

[*] create 'df2215dev': rv=0 (ok)
[*] reload zero: rv=0 (ok)
[*] resume: rv=0 (ok)
[*] mount -o trim still fails (D_CANFREE absent -- path unreachable)
RC=0

=== NOT_TESTABLE for runtime: FREEBLKS path is unreachable on this kernel ===
=== (dm_ops lacks D_CANFREE). Fix validated as: applies + compiles + loads. ===
=== The guard prevents the memset from running on non-READ/WRITE bios.       ===