Re: Solaris cloning woes partly diagnosed

From: Linus Torvalds <torvalds@osdl.org>
To: Junio C Hamano <junkio@cox.net>
Cc: git@vger.kernel.org
Subject: Re: Solaris cloning woes partly diagnosed
Date: Sun, 2 Apr 2006 11:33:46 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.64.0604021118210.3050@g5.osdl.org> (raw)
In-Reply-To: <7vy7yol0nk.fsf@assigned-by-dhcp.cox.net>

On Sun, 2 Apr 2006, Junio C Hamano wrote:
>
> We do two funky things when we have progress bar.  We play games
> with timer signal (setitimer(ITIMER_REAL) and signal(SIGALRM)),
> and we spit out messages to stderr.

I'd be willing to bet that it's the fact that we take signals.

Suddenly, some system calls will either return -1/EINTR, or they'll return 
partial reads or writes. 

We should be pretty good at handling that, but maybe some place forgets.

One thing to do might be to make the itimer use a much higher frequency, 
to trigger the problem more easily.

We do, for example, expect that regular file writing not do that. At least 
"write_sha1_from_fd()" will just do a "write()" without testing the error 
return, which is bad (it would silently create a truncated object if the 
/tmp filesystem filled up). If somebody has their filesystem over NFS 
mounted interruptible, partial writes could also happen.

Ho humm.

		Linus