[Nepomuk] Review Request 106748: FileWatch: Use KAuth to automatically raise the inotify watch limit if we run out of watches.

[Commit Hook]

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://git.reviewboard.kde.org/r/106748/#review32017
-----------------------------------------------------------


This review has been submitted with commit b0a49dab7cfa431835620a1bd50d4826fa2db356 by Simeon Bird to branch master.

- Commit Hook


On May 4, 2013, 3:35 p.m., Simeon Bird wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://git.reviewboard.kde.org/r/106748/
> -----------------------------------------------------------
> 
> (Updated May 4, 2013, 3:35 p.m.)
> 
> 
> Review request for Nepomuk, Sebastian Trueg and Vishesh Handa.
> 
> 
> Description
> -------
> 
> FileWatch: Use KAuth to automatically raise the inotify watch limit if we run out of watches.
> 
> When we run out of watches, use a KAuth action to double the inotify
> watch limit (by writing to /proc/sys/fs/inotify/max_user_watches).
> At the same time, make the new setting persist across reboots by writing
> /etc/sysctl.d/97-kde-nepomuk-filewatch-inotify.conf.
> 
> If for some reason raising the limit does not work, print a message to
> syslog.
> 
> While the limit is being raised, no new watches will be added, only
> queued.
> 
> ==Potential issues==
> 
> 1. At the moment there is no way to turn this off, except by not using
> nepomuk or denying the user the requisite kauth permissions. This is the
> sort of thing that people complain about, but I can't really see any
> reason to want to do that - you'd be running nepomuk in a "known broken"
> configuration, which makes no sense.
> 
> 2. the action description string is "To avoid missing file changes,
> raise the folder watch limit", which could probably be improved.
> 
> 3. The method of making the change persist across reboots is to write a
> file to /etc/sysctl.d, which is a bit anti-social. (note that if /etc is
> not writable, it simply does nothing). /etc/sysctl.d should work on all
> systemd distros, debian (including derivatives such as ubuntu) and
> gentoo.
> 
> Part of me wants to make this a separate action, but as I understand it
> this would require a second prompt and a second authorization, which
> would be a bit annoying. Also, the user's file system isn't going away -
> if they wanted a larger limit once, they almost certainly want it again,
> so there are limited reasons for not wanting it permanent. But finer
> grained permissions are a Good Thing, so I'm not so sure about this.
> 
> 4. If the user has manually set the watch limit to a too-low number in
> sysctl.conf, it could potentially over-ride the file in /etc/sysctl.d,
> leading to the prompt appearing on every boot.
> 
> Also, I'd just like to mention that I was quite impressed at how easy to
> KAuth was to work with.
> 
> 
> Diffs
> -----
> 
>   services/filewatch/CMakeLists.txt 338fe8c2b008b1c898d71934e4de3028c0078fca 
>   services/filewatch/kinotify.h e795371d922d483bce29e9eea03c1eeb97738355 
>   services/filewatch/kinotify.cpp 94babfe437ddfa8c9318b8b29dd8c8a03a4e71b1 
>   services/filewatch/nepomukfilewatch.h 66e0112d909a2abefed48d0959323e7f32a5ff9b 
>   services/filewatch/nepomukfilewatch.cpp fbbf3db619516e296bc1e4aa07f53808fbe4a4c0 
>   services/filewatch/org.kde.nepomuk.filewatch.actions PRE-CREATION 
>   services/filewatch/raiselimit.h PRE-CREATION 
>   services/filewatch/raiselimit.cpp PRE-CREATION 
> 
> Diff: http://git.reviewboard.kde.org/r/106748/diff/
> 
> 
> Testing
> -------
> 
> Compiled, ran, raised and lowered the limit a few times.
> 
> 
> Thanks,
> 
> Simeon Bird
> 
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/nepomuk/attachments/20130504/e207b97d/attachment.html>