Re: fatal: Out of memory, getdelim failed under NFS mounts

From

Yaroslav Halchenko <yoh@onerussian.com>

Date

Aug 10, 2017, 20:29 UTC

Message-ID

<20170810202942.s232yr5stjxmmz4t@hopa.kiewit.dartmouth.edu>

In-Reply-To

<20170810200502.rutab4z3ft7gcpjz@sigill.intra.peff.net>

On Thu, 10 Aug 2017, Jeff King wrote:

> On Thu, Aug 10, 2017 at 09:58:37PM +0200, René Scharfe wrote:

> > > So the function is returning -1 and leaving ENOMEM in errno on
> > > Yaroslav's system.

> > > I wonder if we are truly hitting out of memory, though.  The same
> > > symptom could bee seen if getdelim() does not touch errno when it
> > > returns -1, but some other system call earlier set it to ENOMEM,
> > > for example.

> > That can happen when the end of a file is reached; getdelim() returns
> > -1 and leaves errno unchanged.  So we need to set errno to 0 just
> > before that call.

> Good catch. That's a bug in my original conversoin of
> strbuf_getwholeline().

commit 36ef5e3ad2c187d3be664c33dbc8c06e59bceaf4 (HEAD -> bf-seterrno0)
Author: Yaroslav O. Halchenko <yhalchen@smaug.cns.dartmouth.edu>
Date:   Thu Aug 10 20:26:47 2017 +0000

    BF: set errno to 0 before getdelim call to get unbiased assesment later

diff --git a/strbuf.c b/strbuf.c
index 89d22e3b0..323c49ceb 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -476,6 +476,7 @@ int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
        /* Translate slopbuf to NULL, as we cannot call realloc on it */
        if (!sb->alloc)
                sb->buf = NULL;
+       errno = 0;
        r = getdelim(&sb->buf, &sb->alloc, term, fp);
 
        if (r > 0) {

-- 
Yaroslav O. Halchenko
Center for Open Neuroscience     http://centerforopenneuroscience.org
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834                       Fax: +1 (603) 646-1419
WWW:   http://www.linkedin.com/in/yarik