From owner-svn-src-head@FreeBSD.ORG Thu Sep 4 03:31:49 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B2591699; Thu, 4 Sep 2014 03:31:49 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8483A12C0; Thu, 4 Sep 2014 03:31:49 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s843VnsT048906; Thu, 4 Sep 2014 03:31:49 GMT (envelope-from benno@FreeBSD.org) Received: (from benno@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id s843Vn5c048905; Thu, 4 Sep 2014 03:31:49 GMT (envelope-from benno@FreeBSD.org) Message-Id: <201409040331.s843Vn5c048905@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: benno set sender to benno@FreeBSD.org using -f From: Benno Rice Date: Thu, 4 Sep 2014 03:31:49 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r271085 - head/lib/libgeom X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Sep 2014 03:31:49 -0000 Author: benno Date: Thu Sep 4 03:31:48 2014 New Revision: 271085 URL: http://svnweb.freebsd.org/changeset/base/271085 Log: Systems with lots of geom providers can end up with a kern.geom.confxml value too large for the buffer allocated. Work around this by retrying a few times with larger buffer sizes. Submitted by: Scott Ferris Reviewed by: mlaier, ngie Sponsored by: EMC Isilon Storage Division Modified: head/lib/libgeom/geom_getxml.c Modified: head/lib/libgeom/geom_getxml.c ============================================================================== --- head/lib/libgeom/geom_getxml.c Thu Sep 4 03:04:37 2014 (r271084) +++ head/lib/libgeom/geom_getxml.c Thu Sep 4 03:31:48 2014 (r271085) @@ -31,10 +31,23 @@ #include #include +#include #include #include #include "libgeom.h" +/* + * Amount of extra space we allocate to try and anticipate the size of + * confxml. + */ +#define GEOM_GETXML_SLACK 4096 + +/* + * Number of times to retry in the face of the size of confxml exceeding + * that of our buffer. + */ +#define GEOM_GETXML_RETRIES 4 + char * geom_getxml(void) { @@ -42,19 +55,33 @@ geom_getxml(void) size_t l = 0; int mib[3]; size_t sizep; + int retries; sizep = sizeof(mib) / sizeof(*mib); if (sysctlnametomib("kern.geom.confxml", mib, &sizep) != 0) return (NULL); if (sysctl(mib, sizep, NULL, &l, NULL, 0) != 0) return (NULL); - l += 4096; - p = malloc(l); - if (p == NULL) - return (NULL); - if (sysctl(mib, sizep, p, &l, NULL, 0) != 0) { + l += GEOM_GETXML_SLACK; + + for (retries = 0; retries < GEOM_GETXML_RETRIES; retries++) { + p = malloc(l); + if (p == NULL) + return (NULL); + if (sysctl(mib, sizep, p, &l, NULL, 0) == 0) + return (reallocf(p, strlen(p) + 1)); + free(p); - return (NULL); + + if (errno != ENOMEM) + return (NULL); + + /* + * Our buffer wasn't big enough. Make it bigger and + * try again. + */ + l *= 2; } - return (reallocf(p, strlen(p) + 1)); + + return (NULL); }