real-time filesystem monitoring

[Ognen Duzlevski <maketo@sdf.lonestar.org>]

Hi,

I am working on a GPL-ed tool to monitor a filesystem in real time and
then perform a backup as soon as something has changed. In that direction
I tried FAM/libfam and dnotify and both choked on large directory
hierarchies. dnotify seems to require open file descriptors so it is not a
good solution unless one is to carefully control the number of the file
descriptors open and perform (sometimes large and slow) directory
re-reads every time there is some change (whose nature dnotify will not
report). I wanted to also port the code to Windows and provide a free
solution for its users and it turns out implementing such a solution on
Windows is much easier - there is a function called ReadDirectoryChangesW
which will notify an application every time there is a filesystem-wide
change and provide all information about this change. Anything similar on
Linux?

Thank you,
Ognen