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

From: Paulo Alcantara
Date: Tue Apr 15 2025 - 14:28:32 EST


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.