[LU-14301] EOPNOTSUPP, ENOTSUPP, ENOTSUP confusion

• Status: Resolved
• Project: Lustre
• Fix Version/s: Lustre 2.14.0, Lustre 2.16.0, Lustre 2.15.0
• Type: Bug
• Priority: Minor
• Reporter: John Hammond
• Assignee: John Hammond
• Resolution: Fixed
• Severity: 3

Description

llmv tries posix_fallocate() and falls back to ftruncate() if it indicates that the operation is not supported. From llvm-project-llvmorg-11.0.0/llvm/lib/Support/Unix/Path.inc:

std::error_code resize_file(int FD, uint64_t Size) {
#if defined(HAVE_POSIX_FALLOCATE)
  // If we have posix_fallocate use it. Unlike ftruncate it always allocates                                            
  // space, so we get an error if the disk is full.                                                                     
  if (int Err = ::posix_fallocate(FD, 0, Size)) {
#ifdef _AIX
    constexpr int NotSupportedError = ENOTSUP;
#else
    constexpr int NotSupportedError = EOPNOTSUPP;
#endif
    if (Err != EINVAL && Err != NotSupportedError)
      return std::error_code(Err, std::generic_category());
  }
#endif
  // Use ftruncate as a fallback. It may or may not allocate space. At least on                                         
  // OS X with HFS+ it does.                                                                                            
  if (::ftruncate(FD, Size) == -1)
    return std::error_code(errno, std::generic_category());

  return std::error_code();
}

Somewhere on the server side OST_FALLOCATE is failing and we are returning ENOTSUPP but we should be returning EOPNOTSUPP.

Note:

ENOTSUPP is 524 and defined only in the kernel errno.h and is a NFSv3 specific errno.

EOPNOTSUPP (95) is defined in kernel and userspace errno.h.

ENOTSUP is defined in userspace errno.h as an alias for EOPNOTSUPP.

Ideally we should change every ENOTSUPP to EOPNOTSUPP and add a checkpatch warning. (Or almost every if there's some real NFSv3 interaction.)

Comments

[Gerrit Updater]

John L. Hammond ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41148
Subject: LU-14301 llite: return EOPNOTSUPP if fallocate is not supported
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 51216ee83e1bc036e9e7bd19ede536d98cffb244

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41148/
Subject: LU-14301 llite: return EOPNOTSUPP if fallocate is not supported
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 71a9f5a466bfa46436535e3173d1fed37ca12aea

[Peter Jones]

Landed for 2.14

[Gerrit Updater]

John L. Hammond ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41280
Subject: LU-14301 lustre: add ENOTSUPP to spelling.txt
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: b161a8606b589da824c60702ac35e758ce45c9ca

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41280/
Subject: LU-14301 lustre: add ENOTSUPP to spelling.txt
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: e00733f0f87659c936039a58ea738cfb070638bc

[Mahmoud Hanafi]

Is there a back port to 2.12. ?

[Gerrit Updater]

"Andreas Dilger <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/51511
Subject: LU-14301 client: use EOPNOTSUPP instead of ENOTSUPP
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 1a0d553000d5a869f9039bab74dbdbb20d4259b0

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/51511/
Subject: LU-14301 client: use EOPNOTSUPP instead of ENOTSUPP
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: ffd2fc1e17822c013d7790cc8247361c567792af