bfs sends spurious B_STAT_MODIFICATION_TIME notifications after file change

[bonefish]

After a file has been changed (or just touched) BFS starts sending out B_STAT_MODIFICATION_TIME whenever the file is closed after opening it for writing, even if the file wasn't modified. Can be reproduced with the attached test programs:

• Start monitoring a file that hasn't been changed in this session, yet:

  modified_time_monitor /path/to/file
  

• Verify that no spurious notification are sent yet (the test program waits 3s before closing the file):

  open_for_writing /path/to/file
  

• Touch the file. Notifications are received as expected.
• Run open_for_writing again. This time after close() a spurious notification is received.

Tested in the package-management branch, which corresponds to master hrev45747.

[axeld]

Can't reproduce with the steps you mentioned in hrev45817.

In theory this can happen if either Inode::fOldLastModified is not correctly maintained at some place, or if updating the last modified index failed, as that's fOldLastModified's main purpose.

Do you by any chance reproduce this on a volume without indices?

[axeld]

Can you try to remove line 381 from Index.cpp (​http://cgit.haiku-os.org/haiku/tree/src/add-ons/kernel/file_systems/bfs/Index.cpp#n381)? I think that should fix your issue, in case it's really related to a volume without indices.

[bonefish]

Confirmed that the issue only occurs with a volume without indices and that the suggested change fixes it.

[axeld]

Fixed in hrev50874. Obviously needed some time to think it over :-)