Re: A few concerns about fanotify implementation.

[Vasily Novikov <vasily.novikov-BkmlMuIjteXqlBn2x/YWAg@public.gmane.org>]

Douglas,

>> 1. The file is thrown out of the cache only when it is modified. But in
>> case there are different scan options for different dirs that's not
>> enough. So we also need it to be evicted from cache on rename or number
>> of hard links change.
>
> This is interesting, as it makes the cache less efficient for those
> users who don't have different scanning within a filesystem.

If you consider overhead is a problem here it could be solved by adding 
some flag to a fsnotify group that would be responsible for whether file 
would be evicted from cache on modify only or on renaming or changing 
attributes as well for each group.

Another thought about this issue: it solves the problem only if a file 
is moved/renamed but not a directory. I just don't know how to resolve 
it without adding too much overhead.

Forgot to write that it would also be nice to have a possibility to set 
cache size (i.e. group->fanotify_data.max_marks).

-- 
Best regards,

Vasily Novikov | Software developer | Kaspersky Lab

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