Re: [netfs/cifs - Linux 6.14] loop on file cat + file copy when files are on CIFS share

From: Nicolas Baranger
Date: Thu Apr 17 2025 - 06:10:42 EST


Hi Paulo

Resending this mail with content-type: text, sorry !

Thanks again for answer and help, it's good to hear you're back to health.

Thanks for the trace. I was finally able to reproduce your issue and will provide you with a fix soon.

Perfect... And thanks !

If you need more traces or details on (both?) issues :

- 1) infinite loop issue during 'cat' or 'copy' since Linux 6.14.0

- 2) (don't know if it's related) the very high number of several bytes TCP packets transmitted in SMB transaction (more than a hundred) for a 5 bytes file transfert under Linux 6.13.8

Do not hesitate to ask, I would be happy to help.

Kind regards
Nicolas




Le 2025-04-15 20:28, Paulo Alcantara a écrit :

Hi Nicolas,

Sorry for the delay as I've got busy with some downstream work.

Nicolas Baranger <nicolas.baranger@xxxxxx> writes:

I'll look into it as soon as I recover from my illness. Hope you're doing better

I'm fully recovered now, thanks :-)

I had to rollback to linux 6.13.8 to be able to use the SMB share and
here is what I constat
(don't know if it's a normal behavior but if yes, SMB seems to be a very
very unefficient protocol)

I think the issue can be buffer related:
On Linux 6.13.8 the copy and cat of the 5 bytes 'toto' file containing
only ascii string 'toto' is working fine but here is what I capture with
tcpdump during transfert of toto file:
https://xba.soartist.net/t6.pcap
131 tcp packets to transfer a 5 byte file...
Isn't there a problem ?
Openning the pcap file with wireshark show a lot of lines:
25 0.005576 10.0.10.100 10.0.10.25 SMB2 1071 Read Response, Error:
STATUS_END_OF_FILE
It seems that those lines appears after the 5 bytes 'toto' file had been
transferred, and it continue until the last ACK recieved

Thanks for the trace. I was finally able to reproduce your issue and
will provide you with a fix soon.