Was following up on a recent question about support for Linux features that are missing that could help us pass more xfstests Looking at the standard fstests for Linux (xfstests that are skipped or fail for cifs.ko) to find 'features' that would help, perhaps extending the current POSIX Extensions or adding a couple of SMB3.1.1 FSCTLs, I spotted a few obvious ones: 1) renameat2 (RENAME_EXCHANGE) and renameat2(WHITEOUT) 2) FITRIM support 3) trusted namespace (perhaps xattr/EA extension) 4) attr namespace 5) deduplication 6) chattr -i 7) unshare (namespace command) 8) delayed allocation 9) dax 10) attr namespace security 11) fstrim 12) chattr +s 13) exchange range Any thoughts on which of these which would be 'easy' for samba and/or ksmbd server to implement (e.g. as new fsctls)? -- Thanks, Steve