Regression: 2.6.25-rc8: FTP transfer errors

From: Mark Lord
Date: Wed Apr 09 2008 - 10:07:22 EST


Mark Lord wrote:
Mark Lord wrote:
Today I've been using 2.6.25-rc8 with an old embedded build system here
for my empegs. One shell script calls out to /usr/bin/ftp to transfer
an image to a remote system, and then read it back again and compare.

The compare is failing, most (but not all) of the time,
but only on 2.6.25-rc8, not on 2.6.24. Verified by switching
back and forth between kernel versions for a short spell.

The ftp client is netkit-ftp 0.17-16 on Kubuntu feisty.

Switching to ncftpput/ncftpget avoids it on 2.6.25,
but I wonder where the problem is.

Now verified that the data loss occurs in the outbound direction.
The readback data is the same, regardless of which client s/w is used.

So something in 2.6.25 is incompatible with the ftp client binary, or libs,
that are installed here. Or some other problem.
..

Recap, with more info:

The host system is running 2.6.25-rc8-git. It uses netkit-ftp to
send a file to the remote system. Using strace shows that the
entire file was read, and passed to write() for the outbound socket.

The remote system is running linux-2.2.xx, and is reporting -EPIPE
from net/socket.c::sock_recvmsg() before all of the data has been received,
and thus ends up with a short file, missing data at the end.

This exact sequence, with the exact same software,
works fine when the host system is NOT running 2.6.25-*,
(eg. 2.6.11 through 2.6.24 are fine).

Something may be broken here.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/