Bug 312113

Summary:	nepomuk 4.9.95 gets stuck on recursive directory structures and uses 100% cpu
Product:	[Unmaintained] nepomuk	Reporter:	Daniel Eklöf <daniel>
Component:	filewatch	Assignee:	Nepomuk Bugs Coordination <nepomuk-bugs>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	jessie, me
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:	http://commits.kde.org/nepomuk-core/3daabb6407383b0620b8c6db9973fc9be8f0a6fd	Version Fixed In:
Sentry Crash Report:
Attachments:	Strace output from nepomukservices while being stuck at 100% cpu usage GDB backtrace

Description Daniel Eklöf 2012-12-23 12:42:51 UTC

After installing KDE 4.10 rc1 (4.9.95), I started seeing nepomukservices using 100% cpu.

An strace shows what appears to be nepomuk being stuck in a directory with recursive links (xmlrpc-c/src/cpp/srcdir -> xmlrpc-c).

strace output will be attached. If you look for a specific file, for example libxmlrpc_util.so, and search for it, you'll find it several times, each time deeper  down in the dir hierarchy.

It's also worth noting that this directory hierarchy is in a directory that should have been excluded from indexing (as far as I know, guess there might be a link somewhere from an indexed directory - should nepomuk follow links outside indexed dirs?).

Reproducible: Always

Steps to Reproduce:
1. Create a directory hierarchy with at least one link pointing back to the base dir
(2. Make sure the newly created directory hierarchy is in the selected list of dirs to index)
3. Run nepomuk with file indexing enabled.
Actual Results:  
Nepomuk is stuck at 100% cpu usage and appears to make no progress

Expected Results:  
Close to no cpu usage, and progress while indexing.

Comment 1 Daniel Eklöf 2012-12-23 12:45:00 UTC

Created attachment 75976 [details]
Strace output from nepomukservices while being stuck at 100% cpu usage

Comment 2 Vishesh Handa 2012-12-23 13:30:48 UTC

I'm sorry. I'm not sure how to read the strace. Could you please provide the following information?

1. Full application name - nepomukservicestub <pluginName>
2. GDB Backtrace?

You can obtain the gdb backtrace as follows -

$ ps aux | grep nepomuk # Get the pid of that process
$ gdb --pid <pid>
$ thread apply all backtrace

Comment 3 Daniel Eklöf 2012-12-23 14:28:16 UTC

Created attachment 75977 [details]
GDB backtrace

The offending process is: /usr/bin/nepomukservicestub nepomukfilewatch

The backtrace was taken after verifying with the strace output that it is indeed stuck at the same directory hierarchy.

Comment 4 Vishesh Handa 2012-12-23 14:42:10 UTC

Confirmed. Another developer has also reported the same bug via IRC. I'll try to have it fixed before RC2.

Comment 5 Vishesh Handa 2013-01-02 20:13:23 UTC

Git commit 3daabb6407383b0620b8c6db9973fc9be8f0a6fd by Vishesh Handa.
Committed on 30/12/2012 at 16:11.
Pushed by vhanda into branch 'KDE/4.10'.

FileWatch: Do not add watches for system links

Following system links can lead to various infinite cycles, which is
something we do not ever want.

I'm not sure if there is any advantage gained by adding watches to them?
REVIEW: 108025

M  +3    -2    services/filewatch/kinotify.cpp
M  +0    -11   services/filewatch/nepomukfilewatch.cpp

http://commits.kde.org/nepomuk-core/3daabb6407383b0620b8c6db9973fc9be8f0a6fd

Comment 6 Vishesh Handa 2013-01-07 09:31:40 UTC

*** Bug 312497 has been marked as a duplicate of this bug. ***

Comment 7 Daniel Eklöf 2013-01-07 16:41:15 UTC

Works as expected in 4.10 rc2. Thanks!

Comment 8 Andrew Crouthamel 2018-09-04 15:24:36 UTC

Hello! Sorry to be the bearer of bad news, but this project has been unmaintained for many years so I am closing this bug. Development has moved to Baloo, please try again using the latest version and applications, and submit a new ticket for frameworks-baloo if you still have an issue. Thank you!