[Qt-embedded-interest] Antwort: [SOLVED] Antwort: [Qt-interest] Antwort: Re: Antwort: Re: long-term delay for QDir::entryList (), QDir::count() for directory located on USB stick

[Markus Franke]

Just a small note again on this problem.

The linux kernel documentation states that the mount option "-o usefree" 
could result in problems with recent windows versions.
A rather better method is to improve the algorithm that computes the 
number of free clusters on fat filesystems in the Linux kernel.
Fortunately, I found a patch [1] regarding this problem.
Btw, kernel versions younger than 2.6.22 should not need this patch 
because it should be already mainline.

[1] 
https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/133567/comments/64

Mit freundlichen Grüßen / Best regards

Markus Franke
Entwicklung/ Development

SebaKMT
Hagenuk KMT Kabelmesstechnik GmbH
Röderaue 41
01471 Radeburg / Germany
Reg.Gericht (01067 Dresden) HRB 12567
Geschäftsf.: Dr. Max Iann

Phone +49 (0)35208 84 29142
Fax      +49 (0)35208 84 29249

e-mail: franke.m at sebaKMT.com
web: http//www.sebaKMT.com

qt-embedded-interest-bounces at trolltech.com schrieb am 02.07.2009 17:23:04:

> 
> Just in case anybody has the same problems one day. 
> 
> The mount option "-o usefree" for the USB stick device solves the 
problem. 
> 
> Mit freundlichen Grüßen / Best regards
> 
> Markus Franke
> Entwicklung/ Development
> 
> SebaKMT
> Hagenuk KMT Kabelmesstechnik GmbH
> Röderaue 41
> 01471 Radeburg / Germany
> Reg.Gericht (01067 Dresden) HRB 12567
> Geschäftsf.: Dr. Max Iann
> 
> Phone +49 (0)35208 84 29142
> Fax      +49 (0)35208 84 29249
> 
> e-mail: franke.m at sebaKMT.com
> web: http//www.sebaKMT.com 
> 
> qt-interest-bounces at trolltech.com schrieb am 01.07.2009 16:28:21:
> 
> > 
> > qt-interest-bounces at trolltech.com schrieb am 01.07.2009 16:05:05:
> > 
> > > (i) Use a usb 2.0 device, bus and driver if you have them available. 

> > 
> > The device is USB 2.0 compatible. However, so far we're using an USB 
1.1 
> > OHCI driver. 
> > 
> > > (ii) Use a larger block size with VFAT. Is there any reason you 
really must 
> > > use a 4k block size? 
> > 
> > The USB sticks which we purchase are preformatted with 4 KByte cluster 

> > size. Maybe we should switch over to a different vendor. 
> > 
> > > (iii) Use a different file system. There are many alternatives to 
choose from 
> > > but it depends upon your project requirements. 
> > 
> > The USB stick's should be readable within a windows environment. VFAT 
is 
> > the most suitable filesystem for this, isn't it? 
> > 
> > > (iv) Patch QDir::entryList() and QDir::count() so that they work as 
fast as ls 
> > 
> > Hmmm....sounds not so easy. ;-) 
> > 
> > > (if you are sure that ls is nto using cached results). 
> > 
> > I am sure. 
> > 
> > > (v) Improve the kernel's VFAT driver to work better with small block 
sizes 
> > > over usb 1.1.
> > 
> > Isn't better than the last option. ;-) 
> > 
> > Anyway. Thanks for your help and patience. 
> > 
> > Mit freundlichen Grüßen / Best regards
> > 
> > Markus Franke
> > Entwicklung/ Development
> > 
> > SebaKMT
> > Hagenuk KMT Kabelmesstechnik GmbH
> > Röderaue 41
> > 01471 Radeburg / Germany
> > Reg.Gericht (01067 Dresden) HRB 12567
> > Geschäftsf.: Dr. Max Iann
> > 
> > Phone +49 (0)35208 84 29142
> > Fax      +49 (0)35208 84 29249
> > 
> > e-mail: franke.m at sebaKMT.com
> > web: 
http//www.sebaKMT.com_______________________________________________
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> > Qt-interest at trolltech.com
> > http://lists.trolltech.com/mailman/listinfo/qt-interest
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